From a252e3e35ef8144fb772da70bb93c99a1486097a Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Fri, 3 Oct 2008 14:46:17 +0200 Subject: atmel-mci: Initialize BLKR before sending data transfer command The atmel-mci driver sometimes fails data transfers like this: mmcblk0: error -5 transferring data end_request: I/O error, dev mmcblk0, sector 2749769 end_request: I/O error, dev mmcblk0, sector 2749777 It turns out that this might be caused by the BLKR register (which contains the block size and the number of blocks being transfered) being initialized too late. This patch moves the initialization of BLKR so that it contains the correct value before the block transfer command is sent. This error is difficult to reproduce, but if you insert a long delay (mdelay(10) or thereabouts) between the calls to atmci_start_command() and atmci_submit_data(), all transfers seem to fail without this patch, while I haven't seen any failures with this patch. Reported-by: Hein_Tibosch Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 917035e16da..00008967ef7 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -426,8 +426,6 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) host->sg = NULL; host->data = data; - mci_writel(host, BLKR, MCI_BCNT(data->blocks) - | MCI_BLKLEN(data->blksz)); dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n", MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); @@ -483,6 +481,10 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) if (data->blocks > 1 && data->blksz & 3) goto fail; atmci_set_timeout(host, data); + + /* Must set block count/size before sending command */ + mci_writel(host, BLKR, MCI_BCNT(data->blocks) + | MCI_BLKLEN(data->blksz)); } iflags = MCI_CMDRDY; -- cgit v1.2.3 From c06ad2580dca4eb14ca07541d4f00a3b7cbcf12f Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Thu, 31 Jul 2008 14:49:16 +0200 Subject: atmel-mci: Implement tasklet as a state machine With the current system of completed/pending events, things may get handled in different order depending on which event triggers first. For example, if the data transfer is complete before the command, the stop command must be sent after the command is complete, not the data. This creates a bit of complexity around the stop command. By having the tasklet go through a sequence of clearly defined states, things always happen in a certain order even if the events come at different times, so the stop command can simply be sent when we exit the "sending data" state because we will never enter that state before the command has been sent successfully. Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 249 +++++++++++++++++++++++++------------------ 1 file changed, 145 insertions(+), 104 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 00008967ef7..d834e3756ae 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -36,11 +36,17 @@ enum { EVENT_CMD_COMPLETE = 0, - EVENT_DATA_ERROR, - EVENT_DATA_COMPLETE, - EVENT_STOP_SENT, - EVENT_STOP_COMPLETE, EVENT_XFER_COMPLETE, + EVENT_DATA_COMPLETE, + EVENT_DATA_ERROR, +}; + +enum atmel_mci_state { + STATE_SENDING_CMD = 0, + STATE_SENDING_DATA, + STATE_DATA_BUSY, + STATE_SENDING_STOP, + STATE_DATA_ERROR, }; struct atmel_mci { @@ -56,7 +62,6 @@ struct atmel_mci { u32 cmd_status; u32 data_status; - u32 stop_status; u32 stop_cmdr; u32 mode_reg; @@ -65,6 +70,7 @@ struct atmel_mci { struct tasklet_struct tasklet; unsigned long pending_events; unsigned long completed_events; + enum atmel_mci_state state; int present; int detect_pin; @@ -79,18 +85,12 @@ struct atmel_mci { struct platform_device *pdev; }; -#define atmci_is_completed(host, event) \ - test_bit(event, &host->completed_events) #define atmci_test_and_clear_pending(host, event) \ test_and_clear_bit(event, &host->pending_events) -#define atmci_test_and_set_completed(host, event) \ - test_and_set_bit(event, &host->completed_events) #define atmci_set_completed(host, event) \ set_bit(event, &host->completed_events) #define atmci_set_pending(host, event) \ set_bit(event, &host->pending_events) -#define atmci_clear_pending(host, event) \ - clear_bit(event, &host->pending_events) /* * The debugfs stuff below is mostly optimized away when @@ -258,6 +258,10 @@ static void atmci_init_debugfs(struct atmel_mci *host) if (!node) goto err; + node = debugfs_create_u32("state", S_IRUSR, root, (u32 *)&host->state); + if (!node) + goto err; + node = debugfs_create_x32("pending_events", S_IRUSR, root, (u32 *)&host->pending_events); if (!node) @@ -378,8 +382,6 @@ static void atmci_start_command(struct atmel_mci *host, struct mmc_command *cmd, u32 cmd_flags) { - /* Must read host->cmd after testing event flags */ - smp_rmb(); WARN_ON(host->cmd); host->cmd = cmd; @@ -472,6 +474,7 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) host->mrq = mrq; host->pending_events = 0; host->completed_events = 0; + host->state = STATE_SENDING_CMD; atmci_enable(host); @@ -596,8 +599,10 @@ static struct mmc_host_ops atmci_ops = { }; static void atmci_command_complete(struct atmel_mci *host, - struct mmc_command *cmd, u32 status) + struct mmc_command *cmd) { + u32 status = host->cmd_status; + /* Read the response from the card (up to 16 bytes) */ cmd->resp[0] = mci_readl(host, RSPR); cmd->resp[1] = mci_readl(host, RSPR); @@ -666,20 +671,32 @@ static void atmci_detect_change(unsigned long data) * commands or data transfers. */ mci_writel(host, CR, MCI_CR_SWRST); + mci_readl(host, SR); - if (!atmci_is_completed(host, EVENT_CMD_COMPLETE)) - mrq->cmd->error = -ENOMEDIUM; + host->data = NULL; + host->cmd = NULL; - if (mrq->data && !atmci_is_completed(host, - EVENT_DATA_COMPLETE)) { - host->data = NULL; + switch (host->state) { + case STATE_SENDING_CMD: + mrq->cmd->error = -ENOMEDIUM; + if (!mrq->data) + break; + /* fall through */ + case STATE_SENDING_DATA: mrq->data->error = -ENOMEDIUM; - } - if (mrq->stop && !atmci_is_completed(host, - EVENT_STOP_COMPLETE)) + break; + case STATE_DATA_BUSY: + case STATE_DATA_ERROR: + if (mrq->data->error == -EINPROGRESS) + mrq->data->error = -ENOMEDIUM; + if (!mrq->stop) + break; + /* fall through */ + case STATE_SENDING_STOP: mrq->stop->error = -ENOMEDIUM; + break; + } - host->cmd = NULL; atmci_request_end(host->mmc, mrq); } @@ -693,81 +710,116 @@ static void atmci_tasklet_func(unsigned long priv) struct atmel_mci *host = mmc_priv(mmc); struct mmc_request *mrq = host->mrq; struct mmc_data *data = host->data; + struct mmc_command *cmd = host->cmd; + enum atmel_mci_state state = host->state; + enum atmel_mci_state prev_state; + u32 status; + + state = host->state; dev_vdbg(&mmc->class_dev, - "tasklet: pending/completed/mask %lx/%lx/%x\n", - host->pending_events, host->completed_events, + "tasklet: state %u pending/completed/mask %lx/%lx/%x\n", + state, host->pending_events, host->completed_events, mci_readl(host, IMR)); - if (atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) { - /* - * host->cmd must be set to NULL before the interrupt - * handler sees EVENT_CMD_COMPLETE - */ - host->cmd = NULL; - smp_wmb(); - atmci_set_completed(host, EVENT_CMD_COMPLETE); - atmci_command_complete(host, mrq->cmd, host->cmd_status); - - if (!mrq->cmd->error && mrq->stop - && atmci_is_completed(host, EVENT_XFER_COMPLETE) - && !atmci_test_and_set_completed(host, - EVENT_STOP_SENT)) - send_stop_cmd(host->mmc, mrq->data); - } - if (atmci_test_and_clear_pending(host, EVENT_STOP_COMPLETE)) { - /* - * host->cmd must be set to NULL before the interrupt - * handler sees EVENT_STOP_COMPLETE - */ - host->cmd = NULL; - smp_wmb(); - atmci_set_completed(host, EVENT_STOP_COMPLETE); - atmci_command_complete(host, mrq->stop, host->stop_status); - } - if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) { - u32 status = host->data_status; + do { + prev_state = state; - dev_vdbg(&mmc->class_dev, "data error: status=%08x\n", status); + switch (state) { + case STATE_SENDING_CMD: + if (!atmci_test_and_clear_pending(host, + EVENT_CMD_COMPLETE)) + break; - atmci_set_completed(host, EVENT_DATA_ERROR); - atmci_set_completed(host, EVENT_DATA_COMPLETE); + host->cmd = NULL; + atmci_set_completed(host, EVENT_CMD_COMPLETE); + atmci_command_complete(host, mrq->cmd); + if (!mrq->data || cmd->error) { + atmci_request_end(mmc, host->mrq); + break; + } - if (status & MCI_DTOE) { - dev_dbg(&mmc->class_dev, - "data timeout error\n"); - data->error = -ETIMEDOUT; - } else if (status & MCI_DCRCE) { - dev_dbg(&mmc->class_dev, "data CRC error\n"); - data->error = -EILSEQ; - } else { - dev_dbg(&mmc->class_dev, - "data FIFO error (status=%08x)\n", - status); - data->error = -EIO; - } + prev_state = state = STATE_SENDING_DATA; + /* fall through */ - if (host->present && data->stop - && atmci_is_completed(host, EVENT_CMD_COMPLETE) - && !atmci_test_and_set_completed( - host, EVENT_STOP_SENT)) - send_stop_cmd(host->mmc, data); + case STATE_SENDING_DATA: + if (atmci_test_and_clear_pending(host, + EVENT_DATA_ERROR)) { + if (data->stop) + send_stop_cmd(host->mmc, data); + state = STATE_DATA_ERROR; + break; + } - host->data = NULL; - } - if (atmci_test_and_clear_pending(host, EVENT_DATA_COMPLETE)) { - atmci_set_completed(host, EVENT_DATA_COMPLETE); + if (!atmci_test_and_clear_pending(host, + EVENT_XFER_COMPLETE)) + break; - if (!atmci_is_completed(host, EVENT_DATA_ERROR)) { - data->bytes_xfered = data->blocks * data->blksz; - data->error = 0; - } + atmci_set_completed(host, EVENT_XFER_COMPLETE); + prev_state = state = STATE_DATA_BUSY; + /* fall through */ - host->data = NULL; - } + case STATE_DATA_BUSY: + if (!atmci_test_and_clear_pending(host, + EVENT_DATA_COMPLETE)) + break; + + host->data = NULL; + atmci_set_completed(host, EVENT_DATA_COMPLETE); + status = host->data_status; + if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) { + if (status & MCI_DTOE) { + dev_dbg(&mmc->class_dev, + "data timeout error\n"); + data->error = -ETIMEDOUT; + } else if (status & MCI_DCRCE) { + dev_dbg(&mmc->class_dev, + "data CRC error\n"); + data->error = -EILSEQ; + } else { + dev_dbg(&mmc->class_dev, + "data FIFO error (status=%08x)\n", + status); + data->error = -EIO; + } + } else { + data->bytes_xfered = data->blocks * data->blksz; + data->error = 0; + } + + if (!data->stop) { + atmci_request_end(mmc, host->mrq); + prev_state = state; + break; + } - if (host->mrq && !host->cmd && !host->data) - atmci_request_end(mmc, host->mrq); + prev_state = state = STATE_SENDING_STOP; + if (!data->error) + send_stop_cmd(host->mmc, data); + /* fall through */ + + case STATE_SENDING_STOP: + if (!atmci_test_and_clear_pending(host, + EVENT_CMD_COMPLETE)) + break; + + host->cmd = NULL; + atmci_command_complete(host, mrq->stop); + atmci_request_end(mmc, host->mrq); + prev_state = state; + break; + + case STATE_DATA_ERROR: + if (!atmci_test_and_clear_pending(host, + EVENT_XFER_COMPLETE)) + break; + + state = STATE_DATA_BUSY; + break; + } + } while (state != prev_state); + + host->state = state; } static void atmci_read_data_pio(struct atmel_mci *host) @@ -832,10 +884,7 @@ done: mci_writel(host, IDR, MCI_RXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; - atmci_set_completed(host, EVENT_XFER_COMPLETE); - if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE) - && !atmci_test_and_set_completed(host, EVENT_STOP_SENT)) - send_stop_cmd(host->mmc, data); + atmci_set_pending(host, EVENT_XFER_COMPLETE); } static void atmci_write_data_pio(struct atmel_mci *host) @@ -903,10 +952,7 @@ done: mci_writel(host, IDR, MCI_TXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; - atmci_set_completed(host, EVENT_XFER_COMPLETE); - if (data->stop && atmci_is_completed(host, EVENT_CMD_COMPLETE) - && !atmci_test_and_set_completed(host, EVENT_STOP_SENT)) - send_stop_cmd(host->mmc, data); + atmci_set_pending(host, EVENT_XFER_COMPLETE); } static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status) @@ -915,14 +961,8 @@ static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status) mci_writel(host, IDR, MCI_CMDRDY); - if (atmci_is_completed(host, EVENT_STOP_SENT)) { - host->stop_status = status; - atmci_set_pending(host, EVENT_STOP_COMPLETE); - } else { - host->cmd_status = status; - atmci_set_pending(host, EVENT_CMD_COMPLETE); - } - + host->cmd_status = status; + atmci_set_pending(host, EVENT_CMD_COMPLETE); tasklet_schedule(&host->tasklet); } @@ -951,8 +991,9 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) tasklet_schedule(&host->tasklet); } if (pending & MCI_NOTBUSY) { - mci_writel(host, IDR, (MCI_NOTBUSY - | ATMCI_DATA_ERROR_FLAGS)); + mci_writel(host, IDR, + ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY); + host->data_status = status; atmci_set_pending(host, EVENT_DATA_COMPLETE); tasklet_schedule(&host->tasklet); } -- cgit v1.2.3 From 945533b538c6c6185afc77ba4a81eeba8f6ef8dd Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Fri, 3 Oct 2008 17:48:16 +0200 Subject: atmel-mci: Don't stop the clock between transfers Some cards might get upset if we turn off the clock for extended periods of time. So keep the clock running until the mmc core tells us to turn it off. Also, don't reset the controller between each transfer. That was an attempt to work around earlier bugs, and it never really worked very well. Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 60 ++++++++++++++++---------------------------- 1 file changed, 22 insertions(+), 38 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index d834e3756ae..14ab28da7fa 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -279,23 +279,6 @@ err: "failed to initialize debugfs for controller\n"); } -static void atmci_enable(struct atmel_mci *host) -{ - clk_enable(host->mck); - mci_writel(host, CR, MCI_CR_MCIEN); - mci_writel(host, MR, host->mode_reg); - mci_writel(host, SDCR, host->sdc_reg); -} - -static void atmci_disable(struct atmel_mci *host) -{ - mci_writel(host, CR, MCI_CR_SWRST); - - /* Stall until write is complete, then disable the bus clock */ - mci_readl(host, SR); - clk_disable(host->mck); -} - static inline unsigned int ns_to_clocks(struct atmel_mci *host, unsigned int ns) { @@ -408,8 +391,6 @@ static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq) WARN_ON(host->cmd || host->data); host->mrq = NULL; - atmci_disable(host); - mmc_request_done(mmc, mrq); } @@ -476,8 +457,6 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) host->completed_events = 0; host->state = STATE_SENDING_CMD; - atmci_enable(host); - /* We don't support multiple blocks of weird lengths. */ data = mrq->data; if (data) { @@ -520,7 +499,6 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) return; fail: - atmci_disable(host); host->mrq = NULL; mrq->cmd->error = -EINVAL; mmc_request_done(mmc, mrq); @@ -530,9 +508,21 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct atmel_mci *host = mmc_priv(mmc); + switch (ios->bus_width) { + case MMC_BUS_WIDTH_1: + host->sdc_reg = 0; + break; + case MMC_BUS_WIDTH_4: + host->sdc_reg = MCI_SDCBUS_4BIT; + break; + } + if (ios->clock) { u32 clkdiv; + if (!host->mode_reg) + clk_enable(host->mck); + /* Set clock rate */ clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1; if (clkdiv > 255) { @@ -544,26 +534,20 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF | MCI_MR_RDPROOF; - } - switch (ios->bus_width) { - case MMC_BUS_WIDTH_1: - host->sdc_reg = 0; - break; - case MMC_BUS_WIDTH_4: - host->sdc_reg = MCI_SDCBUS_4BIT; - break; + mci_writel(host, CR, MCI_CR_MCIEN); + mci_writel(host, MR, host->mode_reg); + mci_writel(host, SDCR, host->sdc_reg); + } else { + mci_writel(host, CR, MCI_CR_MCIDIS); + if (host->mode_reg) { + mci_readl(host, MR); + clk_disable(host->mck); + } + host->mode_reg = 0; } switch (ios->power_mode) { - case MMC_POWER_ON: - /* Send init sequence (74 clock cycles) */ - atmci_enable(host); - mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT); - while (!(mci_readl(host, SR) & MCI_CMDRDY)) - cpu_relax(); - atmci_disable(host); - break; default: /* * TODO: None of the currently available AVR32-based -- cgit v1.2.3 From 6b918657b7431e4c5c953b8222ae2f4fc1b2576a Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Thu, 7 Aug 2008 14:08:49 +0200 Subject: atmel-mci: Platform code for supporting multiple mmc slots Add the necessary platform infrastructure to support multiple mmc/sdcard slots all at once through a single controller. Currently, the driver will use the first valid slot it finds and stick with that, but later patches will add support for switching between several slots on the fly. Extend the platform data structure with per-slot information: MMC/SDcard bus width and card detect/write protect pins. This will affect the pin muxing as well as the capabilities announced to the mmc core. Note that board code is now required to supply a mci_platform_data struct to at32_add_device_mci(). Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci-regs.h | 6 ++++-- drivers/mmc/host/atmel-mci.c | 24 ++++++++++++++++++++---- 2 files changed, 24 insertions(+), 6 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h index 26bd80e6503..b58364ed6bb 100644 --- a/drivers/mmc/host/atmel-mci-regs.h +++ b/drivers/mmc/host/atmel-mci-regs.h @@ -25,8 +25,10 @@ #define MCI_SDCR 0x000c /* SD Card / SDIO */ # define MCI_SDCSEL_SLOT_A ( 0 << 0) /* Select SD slot A */ # define MCI_SDCSEL_SLOT_B ( 1 << 0) /* Select SD slot A */ -# define MCI_SDCBUS_1BIT ( 0 << 7) /* 1-bit data bus */ -# define MCI_SDCBUS_4BIT ( 1 << 7) /* 4-bit data bus */ +# define MCI_SDCSEL_MASK ( 3 << 0) +# define MCI_SDCBUS_1BIT ( 0 << 6) /* 1-bit data bus */ +# define MCI_SDCBUS_4BIT ( 2 << 6) /* 4-bit data bus */ +# define MCI_SDCBUS_MASK ( 3 << 6) #define MCI_ARGR 0x0010 /* Command Argument */ #define MCI_CMDR 0x0014 /* Command */ # define MCI_CMDR_CMDNB(x) ((x) << 0) /* Command Opcode */ diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 14ab28da7fa..8170905a040 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -508,9 +508,10 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct atmel_mci *host = mmc_priv(mmc); + host->sdc_reg &= ~MCI_SDCBUS_MASK; switch (ios->bus_width) { case MMC_BUS_WIDTH_1: - host->sdc_reg = 0; + host->sdc_reg |= MCI_SDCBUS_1BIT; break; case MMC_BUS_WIDTH_4: host->sdc_reg = MCI_SDCBUS_4BIT; @@ -1014,9 +1015,11 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) static int __init atmci_probe(struct platform_device *pdev) { struct mci_platform_data *pdata; + struct mci_slot_pdata *slot; struct atmel_mci *host; struct mmc_host *mmc; struct resource *regs; + u32 sdc_reg; int irq; int ret; @@ -1030,6 +1033,17 @@ static int __init atmci_probe(struct platform_device *pdev) if (irq < 0) return irq; + /* TODO: Allow using several slots at once */ + if (pdata->slot[0].bus_width) { + sdc_reg = MCI_SDCSEL_SLOT_A; + slot = &pdata->slot[0]; + } else if (pdata->slot[1].bus_width) { + sdc_reg = MCI_SDCSEL_SLOT_B; + slot = &pdata->slot[1]; + } else { + return -EINVAL; + } + mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev); if (!mmc) return -ENOMEM; @@ -1037,8 +1051,9 @@ static int __init atmci_probe(struct platform_device *pdev) host = mmc_priv(mmc); host->pdev = pdev; host->mmc = mmc; - host->detect_pin = pdata->detect_pin; - host->wp_pin = pdata->wp_pin; + host->detect_pin = slot->detect_pin; + host->wp_pin = slot->wp_pin; + host->sdc_reg = sdc_reg; host->mck = clk_get(&pdev->dev, "mci_clk"); if (IS_ERR(host->mck)) { @@ -1062,7 +1077,8 @@ static int __init atmci_probe(struct platform_device *pdev) mmc->f_min = (host->bus_hz + 511) / 512; mmc->f_max = host->bus_hz / 2; mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; - mmc->caps |= MMC_CAP_4_BIT_DATA; + if (slot->bus_width >= 4) + mmc->caps |= MMC_CAP_4_BIT_DATA; mmc->max_hw_segs = 64; mmc->max_phys_segs = 64; -- cgit v1.2.3 From 965ebf33ea5afb6386f5b57cc71e6572253746b3 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 17 Sep 2008 20:53:55 +0200 Subject: atmel-mci: support multiple mmc slots The Atmel MCI controller can drive multiple cards through separate sets of pins, but only one at a time. This patch adds support for multiplexing access to the controller so that multiple card slots can be used as if they were hooked up to separate mmc controllers. The atmel-mci driver registers each slot as a separate mmc_host. Both access the same common controller state, but they also have some state on their own for card detection/write protect handling, and separate shadows of the MR and SDCR registers. When one of the slots receives a request from the mmc core, the common controller state is checked. If it's idle, the request is submitted immediately. If not, the request is added to a queue. When a request is done, the queue is checked and if there is a queued request, it is submitted before the completion callback is called. This patch also includes a few cleanups and fixes, including a locking overhaul. I had to change the locking extensively in any case, so I might as well try to get it right. The driver no longer takes any irq-safe locks, which may or may not improve the overall system performance. This patch also adds a bit of documentation of the internal data structures. Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 922 ++++++++++++++++++++++++++++--------------- 1 file changed, 614 insertions(+), 308 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 8170905a040..d8ab35175a5 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -42,20 +42,86 @@ enum { }; enum atmel_mci_state { - STATE_SENDING_CMD = 0, + STATE_IDLE = 0, + STATE_SENDING_CMD, STATE_SENDING_DATA, STATE_DATA_BUSY, STATE_SENDING_STOP, STATE_DATA_ERROR, }; +/** + * struct atmel_mci - MMC controller state shared between all slots + * @lock: Spinlock protecting the queue and associated data. + * @regs: Pointer to MMIO registers. + * @sg: Scatterlist entry currently being processed by PIO code, if any. + * @pio_offset: Offset into the current scatterlist entry. + * @cur_slot: The slot which is currently using the controller. + * @mrq: The request currently being processed on @cur_slot, + * or NULL if the controller is idle. + * @cmd: The command currently being sent to the card, or NULL. + * @data: The data currently being transferred, or NULL if no data + * transfer is in progress. + * @cmd_status: Snapshot of SR taken upon completion of the current + * command. Only valid when EVENT_CMD_COMPLETE is pending. + * @data_status: Snapshot of SR taken upon completion of the current + * data transfer. Only valid when EVENT_DATA_COMPLETE or + * EVENT_DATA_ERROR is pending. + * @stop_cmdr: Value to be loaded into CMDR when the stop command is + * to be sent. + * @tasklet: Tasklet running the request state machine. + * @pending_events: Bitmask of events flagged by the interrupt handler + * to be processed by the tasklet. + * @completed_events: Bitmask of events which the state machine has + * processed. + * @state: Tasklet state. + * @queue: List of slots waiting for access to the controller. + * @need_clock_update: Update the clock rate before the next request. + * @need_reset: Reset controller before next request. + * @mode_reg: Value of the MR register. + * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus + * rate and timeout calculations. + * @mapbase: Physical address of the MMIO registers. + * @mck: The peripheral bus clock hooked up to the MMC controller. + * @pdev: Platform device associated with the MMC controller. + * @slot: Slots sharing this MMC controller. + * + * Locking + * ======= + * + * @lock is a softirq-safe spinlock protecting @queue as well as + * @cur_slot, @mrq and @state. These must always be updated + * at the same time while holding @lock. + * + * @lock also protects mode_reg and need_clock_update since these are + * used to synchronize mode register updates with the queue + * processing. + * + * The @mrq field of struct atmel_mci_slot is also protected by @lock, + * and must always be written at the same time as the slot is added to + * @queue. + * + * @pending_events and @completed_events are accessed using atomic bit + * operations, so they don't need any locking. + * + * None of the fields touched by the interrupt handler need any + * locking. However, ordering is important: Before EVENT_DATA_ERROR or + * EVENT_DATA_COMPLETE is set in @pending_events, all data-related + * interrupts must be disabled and @data_status updated with a + * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the + * CMDRDY interupt must be disabled and @cmd_status updated with a + * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the + * bytes_xfered field of @data must be written. This is ensured by + * using barriers. + */ struct atmel_mci { - struct mmc_host *mmc; + spinlock_t lock; void __iomem *regs; struct scatterlist *sg; unsigned int pio_offset; + struct atmel_mci_slot *cur_slot; struct mmc_request *mrq; struct mmc_command *cmd; struct mmc_data *data; @@ -64,25 +130,59 @@ struct atmel_mci { u32 data_status; u32 stop_cmdr; - u32 mode_reg; - u32 sdc_reg; - struct tasklet_struct tasklet; unsigned long pending_events; unsigned long completed_events; enum atmel_mci_state state; + struct list_head queue; - int present; - int detect_pin; - int wp_pin; - - /* For detect pin debouncing */ - struct timer_list detect_timer; - + bool need_clock_update; + bool need_reset; + u32 mode_reg; unsigned long bus_hz; unsigned long mapbase; struct clk *mck; struct platform_device *pdev; + + struct atmel_mci_slot *slot[ATMEL_MCI_MAX_NR_SLOTS]; +}; + +/** + * struct atmel_mci_slot - MMC slot state + * @mmc: The mmc_host representing this slot. + * @host: The MMC controller this slot is using. + * @sdc_reg: Value of SDCR to be written before using this slot. + * @mrq: mmc_request currently being processed or waiting to be + * processed, or NULL when the slot is idle. + * @queue_node: List node for placing this node in the @queue list of + * &struct atmel_mci. + * @clock: Clock rate configured by set_ios(). Protected by host->lock. + * @flags: Random state bits associated with the slot. + * @detect_pin: GPIO pin used for card detection, or negative if not + * available. + * @wp_pin: GPIO pin used for card write protect sending, or negative + * if not available. + * @detect_timer: Timer used for debouncing @detect_pin interrupts. + */ +struct atmel_mci_slot { + struct mmc_host *mmc; + struct atmel_mci *host; + + u32 sdc_reg; + + struct mmc_request *mrq; + struct list_head queue_node; + + unsigned int clock; + unsigned long flags; +#define ATMCI_CARD_PRESENT 0 +#define ATMCI_CARD_NEED_INIT 1 +#define ATMCI_SHUTDOWN 2 + + int detect_pin; + int wp_pin; + + struct timer_list detect_timer; }; #define atmci_test_and_clear_pending(host, event) \ @@ -98,14 +198,15 @@ struct atmel_mci { */ static int atmci_req_show(struct seq_file *s, void *v) { - struct atmel_mci *host = s->private; - struct mmc_request *mrq = host->mrq; + struct atmel_mci_slot *slot = s->private; + struct mmc_request *mrq; struct mmc_command *cmd; struct mmc_command *stop; struct mmc_data *data; /* Make sure we get a consistent snapshot */ - spin_lock_irq(&host->mmc->lock); + spin_lock_bh(&slot->host->lock); + mrq = slot->mrq; if (mrq) { cmd = mrq->cmd; @@ -130,7 +231,7 @@ static int atmci_req_show(struct seq_file *s, void *v) stop->resp[2], stop->error); } - spin_unlock_irq(&host->mmc->lock); + spin_unlock_bh(&slot->host->lock); return 0; } @@ -193,12 +294,16 @@ static int atmci_regs_show(struct seq_file *s, void *v) if (!buf) return -ENOMEM; - /* Grab a more or less consistent snapshot */ - spin_lock_irq(&host->mmc->lock); + /* + * Grab a more or less consistent snapshot. Note that we're + * not disabling interrupts, so IMR and SR may not be + * consistent. + */ + spin_lock_bh(&host->lock); clk_enable(host->mck); memcpy_fromio(buf, host->regs, MCI_REGS_SIZE); clk_disable(host->mck); - spin_unlock_irq(&host->mmc->lock); + spin_unlock_bh(&host->lock); seq_printf(s, "MR:\t0x%08x%s%s CLKDIV=%u\n", buf[MCI_MR / 4], @@ -236,13 +341,13 @@ static const struct file_operations atmci_regs_fops = { .release = single_release, }; -static void atmci_init_debugfs(struct atmel_mci *host) +static void atmci_init_debugfs(struct atmel_mci_slot *slot) { - struct mmc_host *mmc; - struct dentry *root; - struct dentry *node; + struct mmc_host *mmc = slot->mmc; + struct atmel_mci *host = slot->host; + struct dentry *root; + struct dentry *node; - mmc = host->mmc; root = mmc->debugfs_root; if (!root) return; @@ -254,7 +359,7 @@ static void atmci_init_debugfs(struct atmel_mci *host) if (!node) goto err; - node = debugfs_create_file("req", S_IRUSR, root, host, &atmci_req_fops); + node = debugfs_create_file("req", S_IRUSR, root, slot, &atmci_req_fops); if (!node) goto err; @@ -275,8 +380,7 @@ static void atmci_init_debugfs(struct atmel_mci *host) return; err: - dev_err(&host->pdev->dev, - "failed to initialize debugfs for controller\n"); + dev_err(&mmc->class_dev, "failed to initialize debugfs for slot\n"); } static inline unsigned int ns_to_clocks(struct atmel_mci *host, @@ -286,7 +390,7 @@ static inline unsigned int ns_to_clocks(struct atmel_mci *host, } static void atmci_set_timeout(struct atmel_mci *host, - struct mmc_data *data) + struct atmel_mci_slot *slot, struct mmc_data *data) { static unsigned dtomul_to_shift[] = { 0, 4, 7, 8, 10, 12, 16, 20 @@ -309,7 +413,7 @@ static void atmci_set_timeout(struct atmel_mci *host, dtocyc = 15; } - dev_vdbg(&host->mmc->class_dev, "setting timeout to %u cycles\n", + dev_vdbg(&slot->mmc->class_dev, "setting timeout to %u cycles\n", dtocyc << dtomul_to_shift[dtomul]); mci_writel(host, DTOR, (MCI_DTOMUL(dtomul) | MCI_DTOCYC(dtocyc))); } @@ -362,13 +466,12 @@ static u32 atmci_prepare_command(struct mmc_host *mmc, } static void atmci_start_command(struct atmel_mci *host, - struct mmc_command *cmd, - u32 cmd_flags) + struct mmc_command *cmd, u32 cmd_flags) { WARN_ON(host->cmd); host->cmd = cmd; - dev_vdbg(&host->mmc->class_dev, + dev_vdbg(&host->pdev->dev, "start command: ARGR=0x%08x CMDR=0x%08x\n", cmd->arg, cmd_flags); @@ -376,32 +479,19 @@ static void atmci_start_command(struct atmel_mci *host, mci_writel(host, CMDR, cmd_flags); } -static void send_stop_cmd(struct mmc_host *mmc, struct mmc_data *data) +static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data) { - struct atmel_mci *host = mmc_priv(mmc); - atmci_start_command(host, data->stop, host->stop_cmdr); mci_writel(host, IER, MCI_CMDRDY); } -static void atmci_request_end(struct mmc_host *mmc, struct mmc_request *mrq) -{ - struct atmel_mci *host = mmc_priv(mmc); - - WARN_ON(host->cmd || host->data); - host->mrq = NULL; - - mmc_request_done(mmc, mrq); -} - /* * Returns a mask of interrupt flags to be enabled after the whole * request has been prepared. */ -static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) +static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data) { - struct atmel_mci *host = mmc_priv(mmc); - u32 iflags; + u32 iflags; data->error = -EINPROGRESS; @@ -409,10 +499,19 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) host->sg = NULL; host->data = data; - dev_vdbg(&mmc->class_dev, "BLKR=0x%08x\n", - MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); - iflags = ATMCI_DATA_ERROR_FLAGS; + + /* + * Errata: MMC data write operation with less than 12 + * bytes is impossible. + * + * Errata: MCI Transmit Data Register (TDR) FIFO + * corruption when length is not multiple of 4. + */ + if (data->blocks * data->blksz < 12 + || (data->blocks * data->blksz) & 3) + host->need_reset = true; + host->sg = data->sg; host->pio_offset = 0; if (data->flags & MMC_DATA_READ) @@ -423,62 +522,62 @@ static u32 atmci_submit_data(struct mmc_host *mmc, struct mmc_data *data) return iflags; } -static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) +static void atmci_start_request(struct atmel_mci *host, + struct atmel_mci_slot *slot) { - struct atmel_mci *host = mmc_priv(mmc); - struct mmc_data *data; + struct mmc_request *mrq; struct mmc_command *cmd; + struct mmc_data *data; u32 iflags; - u32 cmdflags = 0; - - iflags = mci_readl(host, IMR); - if (iflags) - dev_warn(&mmc->class_dev, "WARNING: IMR=0x%08x\n", - mci_readl(host, IMR)); - - WARN_ON(host->mrq != NULL); - - /* - * We may "know" the card is gone even though there's still an - * electrical connection. If so, we really need to communicate - * this to the MMC core since there won't be any more - * interrupts as the card is completely removed. Otherwise, - * the MMC core might believe the card is still there even - * though the card was just removed very slowly. - */ - if (!host->present) { - mrq->cmd->error = -ENOMEDIUM; - mmc_request_done(mmc, mrq); - return; - } + u32 cmdflags; + mrq = slot->mrq; + host->cur_slot = slot; host->mrq = mrq; + host->pending_events = 0; host->completed_events = 0; - host->state = STATE_SENDING_CMD; - /* We don't support multiple blocks of weird lengths. */ + if (host->need_reset) { + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + mci_writel(host, MR, host->mode_reg); + host->need_reset = false; + } + mci_writel(host, SDCR, slot->sdc_reg); + + iflags = mci_readl(host, IMR); + if (iflags) + dev_warn(&slot->mmc->class_dev, "WARNING: IMR=0x%08x\n", + iflags); + + if (unlikely(test_and_clear_bit(ATMCI_CARD_NEED_INIT, &slot->flags))) { + /* Send init sequence (74 clock cycles) */ + mci_writel(host, CMDR, MCI_CMDR_SPCMD_INIT); + while (!(mci_readl(host, SR) & MCI_CMDRDY)) + cpu_relax(); + } data = mrq->data; if (data) { - if (data->blocks > 1 && data->blksz & 3) - goto fail; - atmci_set_timeout(host, data); + atmci_set_timeout(host, slot, data); /* Must set block count/size before sending command */ mci_writel(host, BLKR, MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); + dev_vdbg(&slot->mmc->class_dev, "BLKR=0x%08x\n", + MCI_BCNT(data->blocks) | MCI_BLKLEN(data->blksz)); } iflags = MCI_CMDRDY; cmd = mrq->cmd; - cmdflags = atmci_prepare_command(mmc, cmd); + cmdflags = atmci_prepare_command(slot->mmc, cmd); atmci_start_command(host, cmd, cmdflags); if (data) - iflags |= atmci_submit_data(mmc, data); + iflags |= atmci_submit_data(host, data); if (mrq->stop) { - host->stop_cmdr = atmci_prepare_command(mmc, mrq->stop); + host->stop_cmdr = atmci_prepare_command(slot->mmc, mrq->stop); host->stop_cmdr |= MCI_CMDR_STOP_XFER; if (!(data->flags & MMC_DATA_WRITE)) host->stop_cmdr |= MCI_CMDR_TRDIR_READ; @@ -495,65 +594,156 @@ static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) * prepared yet.) */ mci_writel(host, IER, iflags); +} - return; +static void atmci_queue_request(struct atmel_mci *host, + struct atmel_mci_slot *slot, struct mmc_request *mrq) +{ + dev_vdbg(&slot->mmc->class_dev, "queue request: state=%d\n", + host->state); + + spin_lock_bh(&host->lock); + slot->mrq = mrq; + if (host->state == STATE_IDLE) { + host->state = STATE_SENDING_CMD; + atmci_start_request(host, slot); + } else { + list_add_tail(&slot->queue_node, &host->queue); + } + spin_unlock_bh(&host->lock); +} -fail: - host->mrq = NULL; - mrq->cmd->error = -EINVAL; - mmc_request_done(mmc, mrq); +static void atmci_request(struct mmc_host *mmc, struct mmc_request *mrq) +{ + struct atmel_mci_slot *slot = mmc_priv(mmc); + struct atmel_mci *host = slot->host; + struct mmc_data *data; + + WARN_ON(slot->mrq); + + /* + * We may "know" the card is gone even though there's still an + * electrical connection. If so, we really need to communicate + * this to the MMC core since there won't be any more + * interrupts as the card is completely removed. Otherwise, + * the MMC core might believe the card is still there even + * though the card was just removed very slowly. + */ + if (!test_bit(ATMCI_CARD_PRESENT, &slot->flags)) { + mrq->cmd->error = -ENOMEDIUM; + mmc_request_done(mmc, mrq); + return; + } + + /* We don't support multiple blocks of weird lengths. */ + data = mrq->data; + if (data && data->blocks > 1 && data->blksz & 3) { + mrq->cmd->error = -EINVAL; + mmc_request_done(mmc, mrq); + } + + atmci_queue_request(host, slot, mrq); } static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci_slot *slot = mmc_priv(mmc); + struct atmel_mci *host = slot->host; + unsigned int i; - host->sdc_reg &= ~MCI_SDCBUS_MASK; + slot->sdc_reg &= ~MCI_SDCBUS_MASK; switch (ios->bus_width) { case MMC_BUS_WIDTH_1: - host->sdc_reg |= MCI_SDCBUS_1BIT; + slot->sdc_reg |= MCI_SDCBUS_1BIT; break; case MMC_BUS_WIDTH_4: - host->sdc_reg = MCI_SDCBUS_4BIT; + slot->sdc_reg = MCI_SDCBUS_4BIT; break; } if (ios->clock) { + unsigned int clock_min = ~0U; u32 clkdiv; - if (!host->mode_reg) + spin_lock_bh(&host->lock); + if (!host->mode_reg) { clk_enable(host->mck); + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + } - /* Set clock rate */ - clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * ios->clock) - 1; + /* + * Use mirror of ios->clock to prevent race with mmc + * core ios update when finding the minimum. + */ + slot->clock = ios->clock; + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i] && host->slot[i]->clock + && host->slot[i]->clock < clock_min) + clock_min = host->slot[i]->clock; + } + + /* Calculate clock divider */ + clkdiv = DIV_ROUND_UP(host->bus_hz, 2 * clock_min) - 1; if (clkdiv > 255) { dev_warn(&mmc->class_dev, "clock %u too slow; using %lu\n", - ios->clock, host->bus_hz / (2 * 256)); + clock_min, host->bus_hz / (2 * 256)); clkdiv = 255; } + /* + * WRPROOF and RDPROOF prevent overruns/underruns by + * stopping the clock when the FIFO is full/empty. + * This state is not expected to last for long. + */ host->mode_reg = MCI_MR_CLKDIV(clkdiv) | MCI_MR_WRPROOF | MCI_MR_RDPROOF; - mci_writel(host, CR, MCI_CR_MCIEN); - mci_writel(host, MR, host->mode_reg); - mci_writel(host, SDCR, host->sdc_reg); + if (list_empty(&host->queue)) + mci_writel(host, MR, host->mode_reg); + else + host->need_clock_update = true; + + spin_unlock_bh(&host->lock); } else { - mci_writel(host, CR, MCI_CR_MCIDIS); - if (host->mode_reg) { - mci_readl(host, MR); - clk_disable(host->mck); + bool any_slot_active = false; + + spin_lock_bh(&host->lock); + slot->clock = 0; + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i] && host->slot[i]->clock) { + any_slot_active = true; + break; + } } - host->mode_reg = 0; + if (!any_slot_active) { + mci_writel(host, CR, MCI_CR_MCIDIS); + if (host->mode_reg) { + mci_readl(host, MR); + clk_disable(host->mck); + } + host->mode_reg = 0; + } + spin_unlock_bh(&host->lock); } switch (ios->power_mode) { + case MMC_POWER_UP: + set_bit(ATMCI_CARD_NEED_INIT, &slot->flags); + break; default: /* * TODO: None of the currently available AVR32-based * boards allow MMC power to be turned off. Implement * power control when this can be tested properly. + * + * We also need to hook this into the clock management + * somehow so that newly inserted cards aren't + * subjected to a fast clock before we have a chance + * to figure out what the maximum rate is. Currently, + * there's no way to avoid this, and there never will + * be for boards that don't support power control. */ break; } @@ -561,28 +751,77 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) static int atmci_get_ro(struct mmc_host *mmc) { - int read_only = 0; - struct atmel_mci *host = mmc_priv(mmc); + int read_only = -ENOSYS; + struct atmel_mci_slot *slot = mmc_priv(mmc); - if (gpio_is_valid(host->wp_pin)) { - read_only = gpio_get_value(host->wp_pin); + if (gpio_is_valid(slot->wp_pin)) { + read_only = gpio_get_value(slot->wp_pin); dev_dbg(&mmc->class_dev, "card is %s\n", read_only ? "read-only" : "read-write"); - } else { - dev_dbg(&mmc->class_dev, - "no pin for checking read-only switch." - " Assuming write-enable.\n"); } return read_only; } -static struct mmc_host_ops atmci_ops = { +static int atmci_get_cd(struct mmc_host *mmc) +{ + int present = -ENOSYS; + struct atmel_mci_slot *slot = mmc_priv(mmc); + + if (gpio_is_valid(slot->detect_pin)) { + present = !gpio_get_value(slot->detect_pin); + dev_dbg(&mmc->class_dev, "card is %spresent\n", + present ? "" : "not "); + } + + return present; +} + +static const struct mmc_host_ops atmci_ops = { .request = atmci_request, .set_ios = atmci_set_ios, .get_ro = atmci_get_ro, + .get_cd = atmci_get_cd, }; +/* Called with host->lock held */ +static void atmci_request_end(struct atmel_mci *host, struct mmc_request *mrq) + __releases(&host->lock) + __acquires(&host->lock) +{ + struct atmel_mci_slot *slot = NULL; + struct mmc_host *prev_mmc = host->cur_slot->mmc; + + WARN_ON(host->cmd || host->data); + + /* + * Update the MMC clock rate if necessary. This may be + * necessary if set_ios() is called when a different slot is + * busy transfering data. + */ + if (host->need_clock_update) + mci_writel(host, MR, host->mode_reg); + + host->cur_slot->mrq = NULL; + host->mrq = NULL; + if (!list_empty(&host->queue)) { + slot = list_entry(host->queue.next, + struct atmel_mci_slot, queue_node); + list_del(&slot->queue_node); + dev_vdbg(&host->pdev->dev, "list not empty: %s is next\n", + mmc_hostname(slot->mmc)); + host->state = STATE_SENDING_CMD; + atmci_start_request(host, slot); + } else { + dev_vdbg(&host->pdev->dev, "list empty\n"); + host->state = STATE_IDLE; + } + + spin_unlock(&host->lock); + mmc_request_done(prev_mmc, mrq); + spin_lock(&host->lock); +} + static void atmci_command_complete(struct atmel_mci *host, struct mmc_command *cmd) { @@ -604,7 +843,7 @@ static void atmci_command_complete(struct atmel_mci *host, cmd->error = 0; if (cmd->error) { - dev_dbg(&host->mmc->class_dev, + dev_dbg(&host->pdev->dev, "command error: status=0x%08x\n", status); if (cmd->data) { @@ -618,81 +857,102 @@ static void atmci_command_complete(struct atmel_mci *host, static void atmci_detect_change(unsigned long data) { - struct atmel_mci *host = (struct atmel_mci *)data; - struct mmc_request *mrq = host->mrq; - int present; + struct atmel_mci_slot *slot = (struct atmel_mci_slot *)data; + bool present; + bool present_old; /* - * atmci_remove() sets detect_pin to -1 before freeing the - * interrupt. We must not re-enable the interrupt if it has - * been freed. + * atmci_cleanup_slot() sets the ATMCI_SHUTDOWN flag before + * freeing the interrupt. We must not re-enable the interrupt + * if it has been freed, and if we're shutting down, it + * doesn't really matter whether the card is present or not. */ smp_rmb(); - if (!gpio_is_valid(host->detect_pin)) + if (test_bit(ATMCI_SHUTDOWN, &slot->flags)) return; - enable_irq(gpio_to_irq(host->detect_pin)); - present = !gpio_get_value(host->detect_pin); + enable_irq(gpio_to_irq(slot->detect_pin)); + present = !gpio_get_value(slot->detect_pin); + present_old = test_bit(ATMCI_CARD_PRESENT, &slot->flags); - dev_vdbg(&host->pdev->dev, "detect change: %d (was %d)\n", - present, host->present); + dev_vdbg(&slot->mmc->class_dev, "detect change: %d (was %d)\n", + present, present_old); - if (present != host->present) { - dev_dbg(&host->mmc->class_dev, "card %s\n", + if (present != present_old) { + struct atmel_mci *host = slot->host; + struct mmc_request *mrq; + + dev_dbg(&slot->mmc->class_dev, "card %s\n", present ? "inserted" : "removed"); - host->present = present; - /* Reset controller if card is gone */ - if (!present) { - mci_writel(host, CR, MCI_CR_SWRST); - mci_writel(host, IDR, ~0UL); - mci_writel(host, CR, MCI_CR_MCIEN); - } + spin_lock(&host->lock); + + if (!present) + clear_bit(ATMCI_CARD_PRESENT, &slot->flags); + else + set_bit(ATMCI_CARD_PRESENT, &slot->flags); /* Clean up queue if present */ + mrq = slot->mrq; if (mrq) { - /* - * Reset controller to terminate any ongoing - * commands or data transfers. - */ - mci_writel(host, CR, MCI_CR_SWRST); - mci_readl(host, SR); - - host->data = NULL; - host->cmd = NULL; - - switch (host->state) { - case STATE_SENDING_CMD: - mrq->cmd->error = -ENOMEDIUM; - if (!mrq->data) + if (mrq == host->mrq) { + /* + * Reset controller to terminate any ongoing + * commands or data transfers. + */ + mci_writel(host, CR, MCI_CR_SWRST); + mci_writel(host, CR, MCI_CR_MCIEN); + mci_writel(host, MR, host->mode_reg); + + host->data = NULL; + host->cmd = NULL; + + switch (host->state) { + case STATE_IDLE: break; - /* fall through */ - case STATE_SENDING_DATA: - mrq->data->error = -ENOMEDIUM; - break; - case STATE_DATA_BUSY: - case STATE_DATA_ERROR: - if (mrq->data->error == -EINPROGRESS) + case STATE_SENDING_CMD: + mrq->cmd->error = -ENOMEDIUM; + if (!mrq->data) + break; + /* fall through */ + case STATE_SENDING_DATA: mrq->data->error = -ENOMEDIUM; - if (!mrq->stop) break; - /* fall through */ - case STATE_SENDING_STOP: - mrq->stop->error = -ENOMEDIUM; - break; - } + case STATE_DATA_BUSY: + case STATE_DATA_ERROR: + if (mrq->data->error == -EINPROGRESS) + mrq->data->error = -ENOMEDIUM; + if (!mrq->stop) + break; + /* fall through */ + case STATE_SENDING_STOP: + mrq->stop->error = -ENOMEDIUM; + break; + } - atmci_request_end(host->mmc, mrq); + atmci_request_end(host, mrq); + } else { + list_del(&slot->queue_node); + mrq->cmd->error = -ENOMEDIUM; + if (mrq->data) + mrq->data->error = -ENOMEDIUM; + if (mrq->stop) + mrq->stop->error = -ENOMEDIUM; + + spin_unlock(&host->lock); + mmc_request_done(slot->mmc, mrq); + spin_lock(&host->lock); + } } + spin_unlock(&host->lock); - mmc_detect_change(host->mmc, 0); + mmc_detect_change(slot->mmc, 0); } } static void atmci_tasklet_func(unsigned long priv) { - struct mmc_host *mmc = (struct mmc_host *)priv; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci *host = (struct atmel_mci *)priv; struct mmc_request *mrq = host->mrq; struct mmc_data *data = host->data; struct mmc_command *cmd = host->cmd; @@ -700,9 +960,11 @@ static void atmci_tasklet_func(unsigned long priv) enum atmel_mci_state prev_state; u32 status; + spin_lock(&host->lock); + state = host->state; - dev_vdbg(&mmc->class_dev, + dev_vdbg(&host->pdev->dev, "tasklet: state %u pending/completed/mask %lx/%lx/%x\n", state, host->pending_events, host->completed_events, mci_readl(host, IMR)); @@ -711,6 +973,9 @@ static void atmci_tasklet_func(unsigned long priv) prev_state = state; switch (state) { + case STATE_IDLE: + break; + case STATE_SENDING_CMD: if (!atmci_test_and_clear_pending(host, EVENT_CMD_COMPLETE)) @@ -720,8 +985,8 @@ static void atmci_tasklet_func(unsigned long priv) atmci_set_completed(host, EVENT_CMD_COMPLETE); atmci_command_complete(host, mrq->cmd); if (!mrq->data || cmd->error) { - atmci_request_end(mmc, host->mrq); - break; + atmci_request_end(host, host->mrq); + goto unlock; } prev_state = state = STATE_SENDING_DATA; @@ -731,7 +996,7 @@ static void atmci_tasklet_func(unsigned long priv) if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) { if (data->stop) - send_stop_cmd(host->mmc, data); + send_stop_cmd(host, data); state = STATE_DATA_ERROR; break; } @@ -754,15 +1019,15 @@ static void atmci_tasklet_func(unsigned long priv) status = host->data_status; if (unlikely(status & ATMCI_DATA_ERROR_FLAGS)) { if (status & MCI_DTOE) { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data timeout error\n"); data->error = -ETIMEDOUT; } else if (status & MCI_DCRCE) { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data CRC error\n"); data->error = -EILSEQ; } else { - dev_dbg(&mmc->class_dev, + dev_dbg(&host->pdev->dev, "data FIFO error (status=%08x)\n", status); data->error = -EIO; @@ -773,14 +1038,13 @@ static void atmci_tasklet_func(unsigned long priv) } if (!data->stop) { - atmci_request_end(mmc, host->mrq); - prev_state = state; - break; + atmci_request_end(host, host->mrq); + goto unlock; } prev_state = state = STATE_SENDING_STOP; if (!data->error) - send_stop_cmd(host->mmc, data); + send_stop_cmd(host, data); /* fall through */ case STATE_SENDING_STOP: @@ -790,9 +1054,8 @@ static void atmci_tasklet_func(unsigned long priv) host->cmd = NULL; atmci_command_complete(host, mrq->stop); - atmci_request_end(mmc, host->mrq); - prev_state = state; - break; + atmci_request_end(host, host->mrq); + goto unlock; case STATE_DATA_ERROR: if (!atmci_test_and_clear_pending(host, @@ -805,6 +1068,9 @@ static void atmci_tasklet_func(unsigned long priv) } while (state != prev_state); host->state = state; + +unlock: + spin_unlock(&host->lock); } static void atmci_read_data_pio(struct atmel_mci *host) @@ -854,9 +1120,11 @@ static void atmci_read_data_pio(struct atmel_mci *host) mci_writel(host, IDR, (MCI_NOTBUSY | MCI_RXRDY | ATMCI_DATA_ERROR_FLAGS)); host->data_status = status; + data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); - break; + return; } } while (status & MCI_RXRDY); @@ -869,6 +1137,7 @@ done: mci_writel(host, IDR, MCI_RXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_XFER_COMPLETE); } @@ -922,9 +1191,11 @@ static void atmci_write_data_pio(struct atmel_mci *host) mci_writel(host, IDR, (MCI_NOTBUSY | MCI_TXRDY | ATMCI_DATA_ERROR_FLAGS)); host->data_status = status; + data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); - break; + return; } } while (status & MCI_TXRDY); @@ -937,29 +1208,26 @@ done: mci_writel(host, IDR, MCI_TXRDY); mci_writel(host, IER, MCI_NOTBUSY); data->bytes_xfered += nbytes; + smp_wmb(); atmci_set_pending(host, EVENT_XFER_COMPLETE); } -static void atmci_cmd_interrupt(struct mmc_host *mmc, u32 status) +static void atmci_cmd_interrupt(struct atmel_mci *host, u32 status) { - struct atmel_mci *host = mmc_priv(mmc); - mci_writel(host, IDR, MCI_CMDRDY); host->cmd_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_CMD_COMPLETE); tasklet_schedule(&host->tasklet); } static irqreturn_t atmci_interrupt(int irq, void *dev_id) { - struct mmc_host *mmc = dev_id; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci *host = dev_id; u32 status, mask, pending; unsigned int pass_count = 0; - spin_lock(&mmc->lock); - do { status = mci_readl(host, SR); mask = mci_readl(host, IMR); @@ -971,7 +1239,9 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS | MCI_RXRDY | MCI_TXRDY); pending &= mci_readl(host, IMR); + host->data_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_ERROR); tasklet_schedule(&host->tasklet); } @@ -979,6 +1249,7 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY); host->data_status = status; + smp_wmb(); atmci_set_pending(host, EVENT_DATA_COMPLETE); tasklet_schedule(&host->tasklet); } @@ -988,18 +1259,15 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) atmci_write_data_pio(host); if (pending & MCI_CMDRDY) - atmci_cmd_interrupt(mmc, status); + atmci_cmd_interrupt(host, status); } while (pass_count++ < 5); - spin_unlock(&mmc->lock); - return pass_count ? IRQ_HANDLED : IRQ_NONE; } static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) { - struct mmc_host *mmc = dev_id; - struct atmel_mci *host = mmc_priv(mmc); + struct atmel_mci_slot *slot = dev_id; /* * Disable interrupts until the pin has stabilized and check @@ -1007,21 +1275,122 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) * middle of the timer routine when this interrupt triggers. */ disable_irq_nosync(irq); - mod_timer(&host->detect_timer, jiffies + msecs_to_jiffies(20)); + mod_timer(&slot->detect_timer, jiffies + msecs_to_jiffies(20)); return IRQ_HANDLED; } +static int __init atmci_init_slot(struct atmel_mci *host, + struct mci_slot_pdata *slot_data, unsigned int id, + u32 sdc_reg) +{ + struct mmc_host *mmc; + struct atmel_mci_slot *slot; + + mmc = mmc_alloc_host(sizeof(struct atmel_mci_slot), &host->pdev->dev); + if (!mmc) + return -ENOMEM; + + slot = mmc_priv(mmc); + slot->mmc = mmc; + slot->host = host; + slot->detect_pin = slot_data->detect_pin; + slot->wp_pin = slot_data->wp_pin; + slot->sdc_reg = sdc_reg; + + mmc->ops = &atmci_ops; + mmc->f_min = DIV_ROUND_UP(host->bus_hz, 512); + mmc->f_max = host->bus_hz / 2; + mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; + if (slot_data->bus_width >= 4) + mmc->caps |= MMC_CAP_4_BIT_DATA; + + mmc->max_hw_segs = 64; + mmc->max_phys_segs = 64; + mmc->max_req_size = 32768 * 512; + mmc->max_blk_size = 32768; + mmc->max_blk_count = 512; + + /* Assume card is present initially */ + set_bit(ATMCI_CARD_PRESENT, &slot->flags); + if (gpio_is_valid(slot->detect_pin)) { + if (gpio_request(slot->detect_pin, "mmc_detect")) { + dev_dbg(&mmc->class_dev, "no detect pin available\n"); + slot->detect_pin = -EBUSY; + } else if (gpio_get_value(slot->detect_pin)) { + clear_bit(ATMCI_CARD_PRESENT, &slot->flags); + } + } + + if (!gpio_is_valid(slot->detect_pin)) + mmc->caps |= MMC_CAP_NEEDS_POLL; + + if (gpio_is_valid(slot->wp_pin)) { + if (gpio_request(slot->wp_pin, "mmc_wp")) { + dev_dbg(&mmc->class_dev, "no WP pin available\n"); + slot->wp_pin = -EBUSY; + } + } + + host->slot[id] = slot; + mmc_add_host(mmc); + + if (gpio_is_valid(slot->detect_pin)) { + int ret; + + setup_timer(&slot->detect_timer, atmci_detect_change, + (unsigned long)slot); + + ret = request_irq(gpio_to_irq(slot->detect_pin), + atmci_detect_interrupt, + IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, + "mmc-detect", slot); + if (ret) { + dev_dbg(&mmc->class_dev, + "could not request IRQ %d for detect pin\n", + gpio_to_irq(slot->detect_pin)); + gpio_free(slot->detect_pin); + slot->detect_pin = -EBUSY; + } + } + + atmci_init_debugfs(slot); + + return 0; +} + +static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot, + unsigned int id) +{ + /* Debugfs stuff is cleaned up by mmc core */ + + set_bit(ATMCI_SHUTDOWN, &slot->flags); + smp_wmb(); + + mmc_remove_host(slot->mmc); + + if (gpio_is_valid(slot->detect_pin)) { + int pin = slot->detect_pin; + + free_irq(gpio_to_irq(pin), slot); + del_timer_sync(&slot->detect_timer); + gpio_free(pin); + } + if (gpio_is_valid(slot->wp_pin)) + gpio_free(slot->wp_pin); + + slot->host->slot[id] = NULL; + mmc_free_host(slot->mmc); +} + static int __init atmci_probe(struct platform_device *pdev) { struct mci_platform_data *pdata; - struct mci_slot_pdata *slot; - struct atmel_mci *host; - struct mmc_host *mmc; - struct resource *regs; - u32 sdc_reg; - int irq; - int ret; + struct atmel_mci *host; + struct resource *regs; + unsigned int nr_slots; + int irq; + int ret; regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!regs) @@ -1033,27 +1402,13 @@ static int __init atmci_probe(struct platform_device *pdev) if (irq < 0) return irq; - /* TODO: Allow using several slots at once */ - if (pdata->slot[0].bus_width) { - sdc_reg = MCI_SDCSEL_SLOT_A; - slot = &pdata->slot[0]; - } else if (pdata->slot[1].bus_width) { - sdc_reg = MCI_SDCSEL_SLOT_B; - slot = &pdata->slot[1]; - } else { - return -EINVAL; - } - - mmc = mmc_alloc_host(sizeof(struct atmel_mci), &pdev->dev); - if (!mmc) + host = kzalloc(sizeof(struct atmel_mci), GFP_KERNEL); + if (!host) return -ENOMEM; - host = mmc_priv(mmc); host->pdev = pdev; - host->mmc = mmc; - host->detect_pin = slot->detect_pin; - host->wp_pin = slot->wp_pin; - host->sdc_reg = sdc_reg; + spin_lock_init(&host->lock); + INIT_LIST_HEAD(&host->queue); host->mck = clk_get(&pdev->dev, "mci_clk"); if (IS_ERR(host->mck)) { @@ -1073,123 +1428,74 @@ static int __init atmci_probe(struct platform_device *pdev) host->mapbase = regs->start; - mmc->ops = &atmci_ops; - mmc->f_min = (host->bus_hz + 511) / 512; - mmc->f_max = host->bus_hz / 2; - mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; - if (slot->bus_width >= 4) - mmc->caps |= MMC_CAP_4_BIT_DATA; - - mmc->max_hw_segs = 64; - mmc->max_phys_segs = 64; - mmc->max_req_size = 32768 * 512; - mmc->max_blk_size = 32768; - mmc->max_blk_count = 512; - - tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)mmc); + tasklet_init(&host->tasklet, atmci_tasklet_func, (unsigned long)host); - ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, mmc); + ret = request_irq(irq, atmci_interrupt, 0, pdev->dev.bus_id, host); if (ret) goto err_request_irq; - /* Assume card is present if we don't have a detect pin */ - host->present = 1; - if (gpio_is_valid(host->detect_pin)) { - if (gpio_request(host->detect_pin, "mmc_detect")) { - dev_dbg(&mmc->class_dev, "no detect pin available\n"); - host->detect_pin = -1; - } else { - host->present = !gpio_get_value(host->detect_pin); - } - } - - if (!gpio_is_valid(host->detect_pin)) - mmc->caps |= MMC_CAP_NEEDS_POLL; - - if (gpio_is_valid(host->wp_pin)) { - if (gpio_request(host->wp_pin, "mmc_wp")) { - dev_dbg(&mmc->class_dev, "no WP pin available\n"); - host->wp_pin = -1; - } - } - platform_set_drvdata(pdev, host); - mmc_add_host(mmc); - - if (gpio_is_valid(host->detect_pin)) { - setup_timer(&host->detect_timer, atmci_detect_change, - (unsigned long)host); - - ret = request_irq(gpio_to_irq(host->detect_pin), - atmci_detect_interrupt, - IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, - "mmc-detect", mmc); - if (ret) { - dev_dbg(&mmc->class_dev, - "could not request IRQ %d for detect pin\n", - gpio_to_irq(host->detect_pin)); - gpio_free(host->detect_pin); - host->detect_pin = -1; - } + /* We need at least one slot to succeed */ + nr_slots = 0; + ret = -ENODEV; + if (pdata->slot[0].bus_width) { + ret = atmci_init_slot(host, &pdata->slot[0], + MCI_SDCSEL_SLOT_A, 0); + if (!ret) + nr_slots++; + } + if (pdata->slot[1].bus_width) { + ret = atmci_init_slot(host, &pdata->slot[1], + MCI_SDCSEL_SLOT_B, 1); + if (!ret) + nr_slots++; } - dev_info(&mmc->class_dev, - "Atmel MCI controller at 0x%08lx irq %d\n", - host->mapbase, irq); + if (!nr_slots) + goto err_init_slot; - atmci_init_debugfs(host); + dev_info(&pdev->dev, + "Atmel MCI controller at 0x%08lx irq %d, %u slots\n", + host->mapbase, irq, nr_slots); return 0; +err_init_slot: + free_irq(irq, host); err_request_irq: iounmap(host->regs); err_ioremap: clk_put(host->mck); err_clk_get: - mmc_free_host(mmc); + kfree(host); return ret; } static int __exit atmci_remove(struct platform_device *pdev) { - struct atmel_mci *host = platform_get_drvdata(pdev); + struct atmel_mci *host = platform_get_drvdata(pdev); + unsigned int i; platform_set_drvdata(pdev, NULL); - if (host) { - /* Debugfs stuff is cleaned up by mmc core */ - - if (gpio_is_valid(host->detect_pin)) { - int pin = host->detect_pin; - - /* Make sure the timer doesn't enable the interrupt */ - host->detect_pin = -1; - smp_wmb(); - - free_irq(gpio_to_irq(pin), host->mmc); - del_timer_sync(&host->detect_timer); - gpio_free(pin); - } - - mmc_remove_host(host->mmc); - - clk_enable(host->mck); - mci_writel(host, IDR, ~0UL); - mci_writel(host, CR, MCI_CR_MCIDIS); - mci_readl(host, SR); - clk_disable(host->mck); + for (i = 0; i < ATMEL_MCI_MAX_NR_SLOTS; i++) { + if (host->slot[i]) + atmci_cleanup_slot(host->slot[i], i); + } - if (gpio_is_valid(host->wp_pin)) - gpio_free(host->wp_pin); + clk_enable(host->mck); + mci_writel(host, IDR, ~0UL); + mci_writel(host, CR, MCI_CR_MCIDIS); + mci_readl(host, SR); + clk_disable(host->mck); - free_irq(platform_get_irq(pdev, 0), host->mmc); - iounmap(host->regs); + free_irq(platform_get_irq(pdev, 0), host); + iounmap(host->regs); - clk_put(host->mck); + clk_put(host->mck); + kfree(host); - mmc_free_host(host->mmc); - } return 0; } -- cgit v1.2.3 From 65e8b083fc8ec303499baa1924ae032d46d29990 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 30 Jul 2008 20:29:03 +0200 Subject: atmel-mci: Add experimental DMA support This adds support for DMA transfers through the generic DMA engine framework with the DMA slave extensions. The driver has been tested using mmc-block and ext3fs on several SD, SDHC and MMC+ cards. Reads and writes work fine, with read transfer rates up to 7.5 MiB/s on fast cards with debugging disabled. Unfortunately, the driver has been known to lock up from time to time with DMA enabled, so DMA support is currently optional and marked EXPERIMENTAL. However, I didn't see any problems while testing 13 different cards (MMC, SD and SDHC of different brands and sizes), so I suspect the "Initialize BLKR before sending data transfer command" fix that was posted earlier fixed this as well. Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/Kconfig | 11 ++ drivers/mmc/host/atmel-mci.c | 274 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 269 insertions(+), 16 deletions(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index ea8d7a3490d..1ce21d4c860 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -114,6 +114,17 @@ config MMC_ATMELMCI If unsure, say N. +config MMC_ATMELMCI_DMA + bool "Atmel MCI DMA support (EXPERIMENTAL)" + depends on MMC_ATMELMCI && DMA_ENGINE && EXPERIMENTAL + help + Say Y here to have the Atmel MCI driver use a DMA engine to + do data transfers and thus increase the throughput and + reduce the CPU utilization. Note that this is highly + experimental and may cause the driver to lock up. + + If unsure, say N. + config MMC_IMX tristate "Motorola i.MX Multimedia Card Interface support" depends on ARCH_IMX diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index d8ab35175a5..d45dfa25938 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -11,6 +11,8 @@ #include #include #include +#include +#include #include #include #include @@ -33,6 +35,7 @@ #include "atmel-mci-regs.h" #define ATMCI_DATA_ERROR_FLAGS (MCI_DCRCE | MCI_DTOE | MCI_OVRE | MCI_UNRE) +#define ATMCI_DMA_THRESHOLD 16 enum { EVENT_CMD_COMPLETE = 0, @@ -50,6 +53,14 @@ enum atmel_mci_state { STATE_DATA_ERROR, }; +struct atmel_mci_dma { +#ifdef CONFIG_MMC_ATMELMCI_DMA + struct dma_client client; + struct dma_chan *chan; + struct dma_async_tx_descriptor *data_desc; +#endif +}; + /** * struct atmel_mci - MMC controller state shared between all slots * @lock: Spinlock protecting the queue and associated data. @@ -62,6 +73,8 @@ enum atmel_mci_state { * @cmd: The command currently being sent to the card, or NULL. * @data: The data currently being transferred, or NULL if no data * transfer is in progress. + * @dma: DMA client state. + * @data_chan: DMA channel being used for the current data transfer. * @cmd_status: Snapshot of SR taken upon completion of the current * command. Only valid when EVENT_CMD_COMPLETE is pending. * @data_status: Snapshot of SR taken upon completion of the current @@ -126,6 +139,9 @@ struct atmel_mci { struct mmc_command *cmd; struct mmc_data *data; + struct atmel_mci_dma dma; + struct dma_chan *data_chan; + u32 cmd_status; u32 data_status; u32 stop_cmdr; @@ -485,6 +501,144 @@ static void send_stop_cmd(struct atmel_mci *host, struct mmc_data *data) mci_writel(host, IER, MCI_CMDRDY); } +#ifdef CONFIG_MMC_ATMELMCI_DMA +static void atmci_dma_cleanup(struct atmel_mci *host) +{ + struct mmc_data *data = host->data; + + dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len, + ((data->flags & MMC_DATA_WRITE) + ? DMA_TO_DEVICE : DMA_FROM_DEVICE)); +} + +static void atmci_stop_dma(struct atmel_mci *host) +{ + struct dma_chan *chan = host->data_chan; + + if (chan) { + chan->device->device_terminate_all(chan); + atmci_dma_cleanup(host); + } else { + /* Data transfer was stopped by the interrupt handler */ + atmci_set_pending(host, EVENT_XFER_COMPLETE); + mci_writel(host, IER, MCI_NOTBUSY); + } +} + +/* This function is called by the DMA driver from tasklet context. */ +static void atmci_dma_complete(void *arg) +{ + struct atmel_mci *host = arg; + struct mmc_data *data = host->data; + + dev_vdbg(&host->pdev->dev, "DMA complete\n"); + + atmci_dma_cleanup(host); + + /* + * If the card was removed, data will be NULL. No point trying + * to send the stop command or waiting for NBUSY in this case. + */ + if (data) { + atmci_set_pending(host, EVENT_XFER_COMPLETE); + tasklet_schedule(&host->tasklet); + + /* + * Regardless of what the documentation says, we have + * to wait for NOTBUSY even after block read + * operations. + * + * When the DMA transfer is complete, the controller + * may still be reading the CRC from the card, i.e. + * the data transfer is still in progress and we + * haven't seen all the potential error bits yet. + * + * The interrupt handler will schedule a different + * tasklet to finish things up when the data transfer + * is completely done. + * + * We may not complete the mmc request here anyway + * because the mmc layer may call back and cause us to + * violate the "don't submit new operations from the + * completion callback" rule of the dma engine + * framework. + */ + mci_writel(host, IER, MCI_NOTBUSY); + } +} + +static int +atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data) +{ + struct dma_chan *chan; + struct dma_async_tx_descriptor *desc; + struct scatterlist *sg; + unsigned int i; + enum dma_data_direction direction; + + /* + * We don't do DMA on "complex" transfers, i.e. with + * non-word-aligned buffers or lengths. Also, we don't bother + * with all the DMA setup overhead for short transfers. + */ + if (data->blocks * data->blksz < ATMCI_DMA_THRESHOLD) + return -EINVAL; + if (data->blksz & 3) + return -EINVAL; + + for_each_sg(data->sg, sg, data->sg_len, i) { + if (sg->offset & 3 || sg->length & 3) + return -EINVAL; + } + + /* If we don't have a channel, we can't do DMA */ + chan = host->dma.chan; + if (chan) { + dma_chan_get(chan); + host->data_chan = chan; + } + + if (!chan) + return -ENODEV; + + if (data->flags & MMC_DATA_READ) + direction = DMA_FROM_DEVICE; + else + direction = DMA_TO_DEVICE; + + desc = chan->device->device_prep_slave_sg(chan, + data->sg, data->sg_len, direction, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + return -ENOMEM; + + host->dma.data_desc = desc; + desc->callback = atmci_dma_complete; + desc->callback_param = host; + desc->tx_submit(desc); + + /* Go! */ + chan->device->device_issue_pending(chan); + + return 0; +} + +#else /* CONFIG_MMC_ATMELMCI_DMA */ + +static int atmci_submit_data_dma(struct atmel_mci *host, struct mmc_data *data) +{ + return -ENOSYS; +} + +static void atmci_stop_dma(struct atmel_mci *host) +{ + /* Data transfer was stopped by the interrupt handler */ + atmci_set_pending(host, EVENT_XFER_COMPLETE); + mci_writel(host, IER, MCI_NOTBUSY); +} + +#endif /* CONFIG_MMC_ATMELMCI_DMA */ + /* * Returns a mask of interrupt flags to be enabled after the whole * request has been prepared. @@ -500,24 +654,27 @@ static u32 atmci_submit_data(struct atmel_mci *host, struct mmc_data *data) host->data = data; iflags = ATMCI_DATA_ERROR_FLAGS; + if (atmci_submit_data_dma(host, data)) { + host->data_chan = NULL; - /* - * Errata: MMC data write operation with less than 12 - * bytes is impossible. - * - * Errata: MCI Transmit Data Register (TDR) FIFO - * corruption when length is not multiple of 4. - */ - if (data->blocks * data->blksz < 12 - || (data->blocks * data->blksz) & 3) - host->need_reset = true; + /* + * Errata: MMC data write operation with less than 12 + * bytes is impossible. + * + * Errata: MCI Transmit Data Register (TDR) FIFO + * corruption when length is not multiple of 4. + */ + if (data->blocks * data->blksz < 12 + || (data->blocks * data->blksz) & 3) + host->need_reset = true; - host->sg = data->sg; - host->pio_offset = 0; - if (data->flags & MMC_DATA_READ) - iflags |= MCI_RXRDY; - else - iflags |= MCI_TXRDY; + host->sg = data->sg; + host->pio_offset = 0; + if (data->flags & MMC_DATA_READ) + iflags |= MCI_RXRDY; + else + iflags |= MCI_TXRDY; + } return iflags; } @@ -848,6 +1005,7 @@ static void atmci_command_complete(struct atmel_mci *host, if (cmd->data) { host->data = NULL; + atmci_stop_dma(host); mci_writel(host, IDR, MCI_NOTBUSY | MCI_TXRDY | MCI_RXRDY | ATMCI_DATA_ERROR_FLAGS); @@ -917,6 +1075,7 @@ static void atmci_detect_change(unsigned long data) /* fall through */ case STATE_SENDING_DATA: mrq->data->error = -ENOMEDIUM; + atmci_stop_dma(host); break; case STATE_DATA_BUSY: case STATE_DATA_ERROR: @@ -995,6 +1154,7 @@ static void atmci_tasklet_func(unsigned long priv) case STATE_SENDING_DATA: if (atmci_test_and_clear_pending(host, EVENT_DATA_ERROR)) { + atmci_stop_dma(host); if (data->stop) send_stop_cmd(host, data); state = STATE_DATA_ERROR; @@ -1280,6 +1440,60 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } +#ifdef CONFIG_MMC_ATMELMCI_DMA + +static inline struct atmel_mci * +dma_client_to_atmel_mci(struct dma_client *client) +{ + return container_of(client, struct atmel_mci, dma.client); +} + +static enum dma_state_client atmci_dma_event(struct dma_client *client, + struct dma_chan *chan, enum dma_state state) +{ + struct atmel_mci *host; + enum dma_state_client ret = DMA_NAK; + + host = dma_client_to_atmel_mci(client); + + switch (state) { + case DMA_RESOURCE_AVAILABLE: + spin_lock_bh(&host->lock); + if (!host->dma.chan) { + host->dma.chan = chan; + ret = DMA_ACK; + } + spin_unlock_bh(&host->lock); + + if (ret == DMA_ACK) + dev_info(&host->pdev->dev, + "Using %s for DMA transfers\n", + chan->dev.bus_id); + break; + + case DMA_RESOURCE_REMOVED: + spin_lock_bh(&host->lock); + if (host->dma.chan == chan) { + host->dma.chan = NULL; + ret = DMA_ACK; + } + spin_unlock_bh(&host->lock); + + if (ret == DMA_ACK) + dev_info(&host->pdev->dev, + "Lost %s, falling back to PIO\n", + chan->dev.bus_id); + break; + + default: + break; + } + + + return ret; +} +#endif /* CONFIG_MMC_ATMELMCI_DMA */ + static int __init atmci_init_slot(struct atmel_mci *host, struct mci_slot_pdata *slot_data, unsigned int id, u32 sdc_reg) @@ -1434,6 +1648,25 @@ static int __init atmci_probe(struct platform_device *pdev) if (ret) goto err_request_irq; +#ifdef CONFIG_MMC_ATMELMCI_DMA + if (pdata->dma_slave) { + struct dma_slave *slave = pdata->dma_slave; + + slave->tx_reg = regs->start + MCI_TDR; + slave->rx_reg = regs->start + MCI_RDR; + + /* Try to grab a DMA channel */ + host->dma.client.event_callback = atmci_dma_event; + dma_cap_set(DMA_SLAVE, host->dma.client.cap_mask); + host->dma.client.slave = slave; + + dma_async_client_register(&host->dma.client); + dma_async_client_chan_request(&host->dma.client); + } else { + dev_notice(&pdev->dev, "DMA not available, using PIO\n"); + } +#endif /* CONFIG_MMC_ATMELMCI_DMA */ + platform_set_drvdata(pdev, host); /* We need at least one slot to succeed */ @@ -1462,6 +1695,10 @@ static int __init atmci_probe(struct platform_device *pdev) return 0; err_init_slot: +#ifdef CONFIG_MMC_ATMELMCI_DMA + if (pdata->dma_slave) + dma_async_client_unregister(&host->dma.client); +#endif free_irq(irq, host); err_request_irq: iounmap(host->regs); @@ -1490,6 +1727,11 @@ static int __exit atmci_remove(struct platform_device *pdev) mci_readl(host, SR); clk_disable(host->mck); +#ifdef CONFIG_MMC_ATMELMCI_DMA + if (host->dma.client.slave) + dma_async_client_unregister(&host->dma.client); +#endif + free_irq(platform_get_irq(pdev, 0), host); iounmap(host->regs); -- cgit v1.2.3 From ca55f46e13dd07b029b0a3d64637f983a6627b23 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Sun, 5 Oct 2008 15:16:59 +0200 Subject: atmel-mci: Don't overwrite error bits when NOTBUSY is set After a data error, we wait for the NOTBUSY bit to be set so that we can be sure the data transfer is completely finished. However, when NOTBUSY is set, the interrupt handler copies the contents of SR into data_status, overwriting any error bits we may have detected earlier. To avoid this, initialize data_status to 0 before starting a request, and don't overwrite it unless it still contains 0. Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index d45dfa25938..02529af7c74 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -694,6 +694,7 @@ static void atmci_start_request(struct atmel_mci *host, host->pending_events = 0; host->completed_events = 0; + host->data_status = 0; if (host->need_reset) { mci_writel(host, CR, MCI_CR_SWRST); @@ -1408,7 +1409,8 @@ static irqreturn_t atmci_interrupt(int irq, void *dev_id) if (pending & MCI_NOTBUSY) { mci_writel(host, IDR, ATMCI_DATA_ERROR_FLAGS | MCI_NOTBUSY); - host->data_status = status; + if (!host->data_status) + host->data_status = status; smp_wmb(); atmci_set_pending(host, EVENT_DATA_COMPLETE); tasklet_schedule(&host->tasklet); -- cgit v1.2.3 From 5e7184ae0dd49456387e8b1cdebc6b2c92fc6d51 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Sun, 5 Oct 2008 15:27:50 +0200 Subject: atmel-mci: Add missing flush_dcache_page() in PIO transfer code Signed-off-by: Haavard Skinnemoen --- drivers/mmc/host/atmel-mci.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/mmc') diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 02529af7c74..7a3f2436b01 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -1253,6 +1253,7 @@ static void atmci_read_data_pio(struct atmel_mci *host) nbytes += 4; if (offset == sg->length) { + flush_dcache_page(sg_page(sg)); host->sg = sg = sg_next(sg); if (!sg) goto done; -- cgit v1.2.3