/* * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/init.h> #include <linux/module.h> #include <linux/device.h> #include <linux/ioport.h> #include <linux/errno.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/spi/spi.h> #include <linux/workqueue.h> #include <linux/delay.h> #include <linux/clk.h> #include <asm/io.h> #include <asm/irq.h> #include <asm/hardware.h> #include <asm/delay.h> #include <asm/dma.h> #include <asm/arch/hardware.h> #include <asm/arch/pxa-regs.h> #include <asm/arch/regs-ssp.h> #include <asm/arch/ssp.h> #include <asm/arch/pxa2xx_spi.h> MODULE_AUTHOR("Stephen Street"); MODULE_DESCRIPTION("PXA2xx SSP SPI Controller"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pxa2xx-spi"); #define MAX_BUSES 3 #define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) #define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) #define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0) /* * for testing SSCR1 changes that require SSP restart, basically * everything except the service and interrupt enables, the pxa270 developer * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this * list, but the PXA255 dev man says all bits without really meaning the * service and interrupt enables */ #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \ | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \ | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \ | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \ | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \ | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM) #define DEFINE_SSP_REG(reg, off) \ static inline u32 read_##reg(void const __iomem *p) \ { return __raw_readl(p + (off)); } \ \ static inline void write_##reg(u32 v, void __iomem *p) \ { __raw_writel(v, p + (off)); } DEFINE_SSP_REG(SSCR0, 0x00) DEFINE_SSP_REG(SSCR1, 0x04) DEFINE_SSP_REG(SSSR, 0x08) DEFINE_SSP_REG(SSITR, 0x0c) DEFINE_SSP_REG(SSDR, 0x10) DEFINE_SSP_REG(SSTO, 0x28) DEFINE_SSP_REG(SSPSP, 0x2c) #define START_STATE ((void*)0) #define RUNNING_STATE ((void*)1) #define DONE_STATE ((void*)2) #define ERROR_STATE ((void*)-1) #define QUEUE_RUNNING 0 #define QUEUE_STOPPED 1 struct driver_data { /* Driver model hookup */ struct platform_device *pdev; /* SSP Info */ struct ssp_device *ssp; /* SPI framework hookup */ enum pxa_ssp_type ssp_type; struct spi_master *master; /* PXA hookup */ struct pxa2xx_spi_master *master_info; /* DMA setup stuff */ int rx_channel; int tx_channel; u32 *null_dma_buf; /* SSP register addresses */ void __iomem *ioaddr; u32 ssdr_physical; /* SSP masks*/ u32 dma_cr1; u32 int_cr1; u32 clear_sr; u32 mask_sr; /* Driver message queue */ struct workqueue_struct *workqueue; struct work_struct pump_messages; spinlock_t lock; struct list_head queue; int busy; int run; /* Message Transfer pump */ struct tasklet_struct pump_transfers; /* Current message transfer state info */ struct spi_message* cur_msg; struct spi_transfer* cur_transfer; struct chip_data *cur_chip; size_t len; void *tx; void *tx_end; void *rx; void *rx_end; int dma_mapped; dma_addr_t rx_dma; dma_addr_t tx_dma; size_t rx_map_len; size_t tx_map_len; u8 n_bytes; u32 dma_width; int cs_change; int (*write)(struct driver_data *drv_data); int (*read)(struct driver_data *drv_data); irqreturn_t (*transfer_handler)(struct driver_data *drv_data); void (*cs_control)(u32 command); }; struct chip_data { u32 cr0; u32 cr1; u32 psp; u32 timeout; u8 n_bytes; u32 dma_width; u32 dma_burst_size; u32 threshold; u32 dma_threshold; u8 enable_dma; u8 bits_per_word; u32 speed_hz; int (*write)(struct driver_data *drv_data); int (*read)(struct driver_data *drv_data); void (*cs_control)(u32 command); }; static void pump_messages(struct work_struct *work); static int flush(struct driver_data *drv_data) { unsigned long limit = loops_per_jiffy << 1; void __iomem *reg = drv_data->ioaddr; do { while (read_SSSR(reg) & SSSR_RNE) { read_SSDR(reg); } } while ((read_SSSR(reg) & SSSR_BSY) && limit--); write_SSSR(SSSR_ROR, reg); return limit; } static void null_cs_control(u32 command) { } static int null_writer(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; u8 n_bytes = drv_data->n_bytes; if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00) || (drv_data->tx == drv_data->tx_end)) return 0; write_SSDR(0, reg); drv_data->tx += n_bytes; return 1; } static int null_reader(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; u8 n_bytes = drv_data->n_bytes; while ((read_SSSR(reg) & SSSR_RNE) && (drv_data->rx < drv_data->rx_end)) { read_SSDR(reg); drv_data->rx += n_bytes; } return drv_data->rx == drv_data->rx_end; } static int u8_writer(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00) || (drv_data->tx == drv_data->tx_end)) return 0; write_SSDR(*(u8 *)(drv_data->tx), reg); ++drv_data->tx; return 1; } static int u8_reader(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) && (drv_data->rx < drv_data->rx_end)) { *(u8 *)(drv_data->rx) = read_SSDR(reg); ++drv_data->rx; } return drv_data->rx == drv_data->rx_end; } static int u16_writer(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00) || (drv_data->tx == drv_data->tx_end)) return 0; write_SSDR(*(u16 *)(drv_data->tx), reg); drv_data->tx += 2; return 1; } static int u16_reader(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) && (drv_data->rx < drv_data->rx_end)) { *(u16 *)(drv_data->rx) = read_SSDR(reg); drv_data->rx += 2; } return drv_data->rx == drv_data->rx_end; } static int u32_writer(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00) || (drv_data->tx == drv_data->tx_end)) return 0; write_SSDR(*(u32 *)(drv_data->tx), reg); drv_data->tx += 4; return 1; } static int u32_reader(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; while ((read_SSSR(reg) & SSSR_RNE) && (drv_data->rx < drv_data->rx_end)) { *(u32 *)(drv_data->rx) = read_SSDR(reg); drv_data->rx += 4; } return drv_data->rx == drv_data->rx_end; } static void *next_transfer(struct driver_data *drv_data) { struct spi_message *msg = drv_data->cur_msg; struct spi_transfer *trans = drv_data->cur_transfer; /* Move to next transfer */ if (trans->transfer_list.next != &msg->transfers) { drv_data->cur_transfer = list_entry(trans->transfer_list.next, struct spi_transfer, transfer_list); return RUNNING_STATE; } else return DONE_STATE; } static int map_dma_buffers(struct driver_data *drv_data) { struct spi_message *msg = drv_data->cur_msg; struct device *dev = &msg->spi->dev; if (!drv_data->cur_chip->enable_dma) return 0; if (msg->is_dma_mapped) return drv_data->rx_dma && drv_data->tx_dma; if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx)) return 0; /* Modify setup if rx buffer is null */ if (drv_data->rx == NULL) { *drv_data->null_dma_buf = 0; drv_data->rx = drv_data->null_dma_buf; drv_data->rx_map_len = 4; } else drv_data->rx_map_len = drv_data->len; /* Modify setup if tx buffer is null */ if (drv_data->tx == NULL) { *drv_data->null_dma_buf = 0; drv_data->tx = drv_data->null_dma_buf; drv_data->tx_map_len = 4; } else drv_data->tx_map_len = drv_data->len; /* Stream map the rx buffer */ drv_data->rx_dma = dma_map_single(dev, drv_data->rx, drv_data->rx_map_len, DMA_FROM_DEVICE); if (dma_mapping_error(drv_data->rx_dma)) return 0; /* Stream map the tx buffer */ drv_data->tx_dma = dma_map_single(dev, drv_data->tx, drv_data->tx_map_len, DMA_TO_DEVICE); if (dma_mapping_error(drv_data->tx_dma)) { dma_unmap_single(dev, drv_data->rx_dma, drv_data->rx_map_len, DMA_FROM_DEVICE); return 0; } return 1; } static void unmap_dma_buffers(struct driver_data *drv_data) { struct device *dev; if (!drv_data->dma_mapped) return; if (!drv_data->cur_msg->is_dma_mapped) { dev = &drv_data->cur_msg->spi->dev; dma_unmap_single(dev, drv_data->rx_dma, drv_data->rx_map_len, DMA_FROM_DEVICE); dma_unmap_single(dev, drv_data->tx_dma, drv_data->tx_map_len, DMA_TO_DEVICE); } drv_data->dma_mapped = 0; } /* caller already set message->status; dma and pio irqs are blocked */ static void giveback(struct driver_data *drv_data) { struct spi_transfer* last_transfer; unsigned long flags; struct spi_message *msg; spin_lock_irqsave(&drv_data->lock, flags); msg = drv_data->cur_msg; drv_data->cur_msg = NULL; drv_data->cur_transfer = NULL; drv_data->cur_chip = NULL; queue_work(drv_data->workqueue, &drv_data->pump_messages); spin_unlock_irqrestore(&drv_data->lock, flags); last_transfer = list_entry(msg->transfers.prev, struct spi_transfer, transfer_list); if (!last_transfer->cs_change) drv_data->cs_control(PXA2XX_CS_DEASSERT); msg->state = NULL; if (msg->complete) msg->complete(msg->context); } static int wait_ssp_rx_stall(void const __iomem *ioaddr) { unsigned long limit = loops_per_jiffy << 1; while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--) cpu_relax(); return limit; } static int wait_dma_channel_stop(int channel) { unsigned long limit = loops_per_jiffy << 1; while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--) cpu_relax(); return limit; } static void dma_error_stop(struct driver_data *drv_data, const char *msg) { void __iomem *reg = drv_data->ioaddr; /* Stop and reset */ DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; write_SSSR(drv_data->clear_sr, reg); write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, reg); flush(drv_data); write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); unmap_dma_buffers(drv_data); dev_err(&drv_data->pdev->dev, "%s\n", msg); drv_data->cur_msg->state = ERROR_STATE; tasklet_schedule(&drv_data->pump_transfers); } static void dma_transfer_complete(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; struct spi_message *msg = drv_data->cur_msg; /* Clear and disable interrupts on SSP and DMA channels*/ write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); write_SSSR(drv_data->clear_sr, reg); DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; if (wait_dma_channel_stop(drv_data->rx_channel) == 0) dev_err(&drv_data->pdev->dev, "dma_handler: dma rx channel stop failed\n"); if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) dev_err(&drv_data->pdev->dev, "dma_transfer: ssp rx stall failed\n"); unmap_dma_buffers(drv_data); /* update the buffer pointer for the amount completed in dma */ drv_data->rx += drv_data->len - (DCMD(drv_data->rx_channel) & DCMD_LENGTH); /* read trailing data from fifo, it does not matter how many * bytes are in the fifo just read until buffer is full * or fifo is empty, which ever occurs first */ drv_data->read(drv_data); /* return count of what was actually read */ msg->actual_length += drv_data->len - (drv_data->rx_end - drv_data->rx); /* Release chip select if requested, transfer delays are * handled in pump_transfers */ if (drv_data->cs_change) drv_data->cs_control(PXA2XX_CS_DEASSERT); /* Move to next transfer */ msg->state = next_transfer(drv_data); /* Schedule transfer tasklet */ tasklet_schedule(&drv_data->pump_transfers); } static void dma_handler(int channel, void *data) { struct driver_data *drv_data = data; u32 irq_status = DCSR(channel) & DMA_INT_MASK; if (irq_status & DCSR_BUSERR) { if (channel == drv_data->tx_channel) dma_error_stop(drv_data, "dma_handler: " "bad bus address on tx channel"); else dma_error_stop(drv_data, "dma_handler: " "bad bus address on rx channel"); return; } /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */ if ((channel == drv_data->tx_channel) && (irq_status & DCSR_ENDINTR) && (drv_data->ssp_type == PXA25x_SSP)) { /* Wait for rx to stall */ if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) dev_err(&drv_data->pdev->dev, "dma_handler: ssp rx stall failed\n"); /* finish this transfer, start the next */ dma_transfer_complete(drv_data); } } static irqreturn_t dma_transfer(struct driver_data *drv_data) { u32 irq_status; void __iomem *reg = drv_data->ioaddr; irq_status = read_SSSR(reg) & drv_data->mask_sr; if (irq_status & SSSR_ROR) { dma_error_stop(drv_data, "dma_transfer: fifo overrun"); return IRQ_HANDLED; } /* Check for false positive timeout */ if ((irq_status & SSSR_TINT) && (DCSR(drv_data->tx_channel) & DCSR_RUN)) { write_SSSR(SSSR_TINT, reg); return IRQ_HANDLED; } if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) { /* Clear and disable timeout interrupt, do the rest in * dma_transfer_complete */ if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, reg); /* finish this transfer, start the next */ dma_transfer_complete(drv_data); return IRQ_HANDLED; } /* Opps problem detected */ return IRQ_NONE; } static void int_error_stop(struct driver_data *drv_data, const char* msg) { void __iomem *reg = drv_data->ioaddr; /* Stop and reset SSP */ write_SSSR(drv_data->clear_sr, reg); write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, reg); flush(drv_data); write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); dev_err(&drv_data->pdev->dev, "%s\n", msg); drv_data->cur_msg->state = ERROR_STATE; tasklet_schedule(&drv_data->pump_transfers); } static void int_transfer_complete(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; /* Stop SSP */ write_SSSR(drv_data->clear_sr, reg); write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, reg); /* Update total byte transfered return count actual bytes read */ drv_data->cur_msg->actual_length += drv_data->len - (drv_data->rx_end - drv_data->rx); /* Release chip select if requested, transfer delays are * handled in pump_transfers */ if (drv_data->cs_change) drv_data->cs_control(PXA2XX_CS_DEASSERT); /* Move to next transfer */ drv_data->cur_msg->state = next_transfer(drv_data); /* Schedule transfer tasklet */ tasklet_schedule(&drv_data->pump_transfers); } static irqreturn_t interrupt_transfer(struct driver_data *drv_data) { void __iomem *reg = drv_data->ioaddr; u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ? drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS; u32 irq_status = read_SSSR(reg) & irq_mask; if (irq_status & SSSR_ROR) { int_error_stop(drv_data, "interrupt_transfer: fifo overrun"); return IRQ_HANDLED; } if (irq_status & SSSR_TINT) { write_SSSR(SSSR_TINT, reg); if (drv_data->read(drv_data)) { int_transfer_complete(drv_data); return IRQ_HANDLED; } } /* Drain rx fifo, Fill tx fifo and prevent overruns */ do { if (drv_data->read(drv_data)) { int_transfer_complete(drv_data); return IRQ_HANDLED; } } while (drv_data->write(drv_data)); if (drv_data->read(drv_data)) { int_transfer_complete(drv_data); return IRQ_HANDLED; } if (drv_data->tx == drv_data->tx_end) { write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg); /* PXA25x_SSP has no timeout, read trailing bytes */ if (drv_data->ssp_type == PXA25x_SSP) { if (!wait_ssp_rx_stall(reg)) { int_error_stop(drv_data, "interrupt_transfer: " "rx stall failed"); return IRQ_HANDLED; } if (!drv_data->read(drv_data)) { int_error_stop(drv_data, "interrupt_transfer: " "trailing byte read failed"); return IRQ_HANDLED; } int_transfer_complete(drv_data); } } /* We did something */ return IRQ_HANDLED; } static irqreturn_t ssp_int(int irq, void *dev_id) { struct driver_data *drv_data = dev_id; void __iomem *reg = drv_data->ioaddr; if (!drv_data->cur_msg) { write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, reg); write_SSSR(drv_data->clear_sr, reg); dev_err(&drv_data->pdev->dev, "bad message state " "in interrupt handler\n"); /* Never fail */ return IRQ_HANDLED; } return drv_data->transfer_handler(drv_data); } static int set_dma_burst_and_threshold(struct chip_data *chip, struct spi_device *spi, u8 bits_per_word, u32 *burst_code, u32 *threshold) { struct pxa2xx_spi_chip *chip_info = (struct pxa2xx_spi_chip *)spi->controller_data; int bytes_per_word; int burst_bytes; int thresh_words; int req_burst_size; int retval = 0; /* Set the threshold (in registers) to equal the same amount of data * as represented by burst size (in bytes). The computation below * is (burst_size rounded up to nearest 8 byte, word or long word) * divided by (bytes/register); the tx threshold is the inverse of * the rx, so that there will always be enough data in the rx fifo * to satisfy a burst, and there will always be enough space in the * tx fifo to accept a burst (a tx burst will overwrite the fifo if * there is not enough space), there must always remain enough empty * space in the rx fifo for any data loaded to the tx fifo. * Whenever burst_size (in bytes) equals bits/word, the fifo threshold * will be 8, or half the fifo; * The threshold can only be set to 2, 4 or 8, but not 16, because * to burst 16 to the tx fifo, the fifo would have to be empty; * however, the minimum fifo trigger level is 1, and the tx will * request service when the fifo is at this level, with only 15 spaces. */ /* find bytes/word */ if (bits_per_word <= 8) bytes_per_word = 1; else if (bits_per_word <= 16) bytes_per_word = 2; else bytes_per_word = 4; /* use struct pxa2xx_spi_chip->dma_burst_size if available */ if (chip_info) req_burst_size = chip_info->dma_burst_size; else { switch (chip->dma_burst_size) { default: /* if the default burst size is not set, * do it now */ chip->dma_burst_size = DCMD_BURST8; case DCMD_BURST8: req_burst_size = 8; break; case DCMD_BURST16: req_burst_size = 16; break; case DCMD_BURST32: req_burst_size = 32; break; } } if (req_burst_size <= 8) { *burst_code = DCMD_BURST8; burst_bytes = 8; } else if (req_burst_size <= 16) { if (bytes_per_word == 1) { /* don't burst more than 1/2 the fifo */ *burst_code = DCMD_BURST8; burst_bytes = 8; retval = 1; } else { *burst_code = DCMD_BURST16; burst_bytes = 16; } } else { if (bytes_per_word == 1) { /* don't burst more than 1/2 the fifo */ *burst_code = DCMD_BURST8; burst_bytes = 8; retval = 1; } else if (bytes_per_word == 2) { /* don't burst more than 1/2 the fifo */ *burst_code = DCMD_BURST16; burst_bytes = 16; retval = 1; } else { *burst_code = DCMD_BURST32; burst_bytes = 32; } } thresh_words = burst_bytes / bytes_per_word; /* thresh_words will be between 2 and 8 */ *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT) | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT); return retval; } static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate) { unsigned long ssp_clk = clk_get_rate(ssp->clk); if (ssp->type == PXA25x_SSP) return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8; else return ((ssp_clk / rate - 1) & 0xfff) << 8; } static void pump_transfers(unsigned long data) { struct driver_data *drv_data = (struct driver_data *)data; struct spi_message *message = NULL; struct spi_transfer *transfer = NULL; struct spi_transfer *previous = NULL; struct chip_data *chip = NULL; struct ssp_device *ssp = drv_data->ssp; void __iomem *reg = drv_data->ioaddr; u32 clk_div = 0; u8 bits = 0; u32 speed = 0; u32 cr0; u32 cr1; u32 dma_thresh = drv_data->cur_chip->dma_threshold; u32 dma_burst = drv_data->cur_chip->dma_burst_size; /* Get current state information */ message = drv_data->cur_msg; transfer = drv_data->cur_transfer; chip = drv_data->cur_chip; /* Handle for abort */ if (message->state == ERROR_STATE) { message->status = -EIO; giveback(drv_data); return; } /* Handle end of message */ if (message->state == DONE_STATE) { message->status = 0; giveback(drv_data); return; } /* Delay if requested at end of transfer*/ if (message->state == RUNNING_STATE) { previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); if (previous->delay_usecs) udelay(previous->delay_usecs); } /* Check transfer length */ if (transfer->len > 8191) { dev_warn(&drv_data->pdev->dev, "pump_transfers: transfer " "length greater than 8191\n"); message->status = -EINVAL; giveback(drv_data); return; } /* Setup the transfer state based on the type of transfer */ if (flush(drv_data) == 0) { dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n"); message->status = -EIO; giveback(drv_data); return; } drv_data->n_bytes = chip->n_bytes; drv_data->dma_width = chip->dma_width; drv_data->cs_control = chip->cs_control; drv_data->tx = (void *)transfer->tx_buf; drv_data->tx_end = drv_data->tx + transfer->len; drv_data->rx = transfer->rx_buf; drv_data->rx_end = drv_data->rx + transfer->len; drv_data->rx_dma = transfer->rx_dma; drv_data->tx_dma = transfer->tx_dma; drv_data->len = transfer->len & DCMD_LENGTH; drv_data->write = drv_data->tx ? chip->write : null_writer; drv_data->read = drv_data->rx ? chip->read : null_reader; drv_data->cs_change = transfer->cs_change; /* Change speed and bit per word on a per transfer */ cr0 = chip->cr0; if (transfer->speed_hz || transfer->bits_per_word) { bits = chip->bits_per_word; speed = chip->speed_hz; if (transfer->speed_hz) speed = transfer->speed_hz; if (transfer->bits_per_word) bits = transfer->bits_per_word; clk_div = ssp_get_clk_div(ssp, speed); if (bits <= 8) { drv_data->n_bytes = 1; drv_data->dma_width = DCMD_WIDTH1; drv_data->read = drv_data->read != null_reader ? u8_reader : null_reader; drv_data->write = drv_data->write != null_writer ? u8_writer : null_writer; } else if (bits <= 16) { drv_data->n_bytes = 2; drv_data->dma_width = DCMD_WIDTH2; drv_data->read = drv_data->read != null_reader ? u16_reader : null_reader; drv_data->write = drv_data->write != null_writer ? u16_writer : null_writer; } else if (bits <= 32) { drv_data->n_bytes = 4; drv_data->dma_width = DCMD_WIDTH4; drv_data->read = drv_data->read != null_reader ? u32_reader : null_reader; drv_data->write = drv_data->write != null_writer ? u32_writer : null_writer; } /* if bits/word is changed in dma mode, then must check the * thresholds and burst also */ if (chip->enable_dma) { if (set_dma_burst_and_threshold(chip, message->spi, bits, &dma_burst, &dma_thresh)) if (printk_ratelimit()) dev_warn(&message->spi->dev, "pump_transfer: " "DMA burst size reduced to " "match bits_per_word\n"); } cr0 = clk_div | SSCR0_Motorola | SSCR0_DataSize(bits > 16 ? bits - 16 : bits) | SSCR0_SSE | (bits > 16 ? SSCR0_EDSS : 0); } message->state = RUNNING_STATE; /* Try to map dma buffer and do a dma transfer if successful */ if ((drv_data->dma_mapped = map_dma_buffers(drv_data))) { /* Ensure we have the correct interrupt handler */ drv_data->transfer_handler = dma_transfer; /* Setup rx DMA Channel */ DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; DSADR(drv_data->rx_channel) = drv_data->ssdr_physical; DTADR(drv_data->rx_channel) = drv_data->rx_dma; if (drv_data->rx == drv_data->null_dma_buf) /* No target address increment */ DCMD(drv_data->rx_channel) = DCMD_FLOWSRC | drv_data->dma_width | dma_burst | drv_data->len; else DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR | DCMD_FLOWSRC | drv_data->dma_width | dma_burst | drv_data->len; /* Setup tx DMA Channel */ DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; DSADR(drv_data->tx_channel) = drv_data->tx_dma; DTADR(drv_data->tx_channel) = drv_data->ssdr_physical; if (drv_data->tx == drv_data->null_dma_buf) /* No source address increment */ DCMD(drv_data->tx_channel) = DCMD_FLOWTRG | drv_data->dma_width | dma_burst | drv_data->len; else DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR | DCMD_FLOWTRG | drv_data->dma_width | dma_burst | drv_data->len; /* Enable dma end irqs on SSP to detect end of transfer */ if (drv_data->ssp_type == PXA25x_SSP) DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN; /* Clear status and start DMA engine */ cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1; write_SSSR(drv_data->clear_sr, reg); DCSR(drv_data->rx_channel) |= DCSR_RUN; DCSR(drv_data->tx_channel) |= DCSR_RUN; } else { /* Ensure we have the correct interrupt handler */ drv_data->transfer_handler = interrupt_transfer; /* Clear status */ cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1; write_SSSR(drv_data->clear_sr, reg); } /* see if we need to reload the config registers */ if ((read_SSCR0(reg) != cr0) || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) != (cr1 & SSCR1_CHANGE_MASK)) { /* stop the SSP, and update the other bits */ write_SSCR0(cr0 & ~SSCR0_SSE, reg); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(chip->timeout, reg); /* first set CR1 without interrupt and service enables */ write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg); /* restart the SSP */ write_SSCR0(cr0, reg); } else { if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(chip->timeout, reg); } /* FIXME, need to handle cs polarity, * this driver uses struct pxa2xx_spi_chip.cs_control to * specify a CS handling function, and it ignores most * struct spi_device.mode[s], including SPI_CS_HIGH */ drv_data->cs_control(PXA2XX_CS_ASSERT); /* after chip select, release the data by enabling service * requests and interrupts, without changing any mode bits */ write_SSCR1(cr1, reg); } static void pump_messages(struct work_struct *work) { struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages); unsigned long flags; /* Lock queue and check for queue work */ spin_lock_irqsave(&drv_data->lock, flags); if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) { drv_data->busy = 0; spin_unlock_irqrestore(&drv_data->lock, flags); return; } /* Make sure we are not already running a message */ if (drv_data->cur_msg) { spin_unlock_irqrestore(&drv_data->lock, flags); return; } /* Extract head of queue */ drv_data->cur_msg = list_entry(drv_data->queue.next, struct spi_message, queue); list_del_init(&drv_data->cur_msg->queue); /* Initial message state*/ drv_data->cur_msg->state = START_STATE; drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next, struct spi_transfer, transfer_list); /* prepare to setup the SSP, in pump_transfers, using the per * chip configuration */ drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi); /* Mark as busy and launch transfers */ tasklet_schedule(&drv_data->pump_transfers); drv_data->busy = 1; spin_unlock_irqrestore(&drv_data->lock, flags); } static int transfer(struct spi_device *spi, struct spi_message *msg) { struct driver_data *drv_data = spi_master_get_devdata(spi->master); unsigned long flags; spin_lock_irqsave(&drv_data->lock, flags); if (drv_data->run == QUEUE_STOPPED) { spin_unlock_irqrestore(&drv_data->lock, flags); return -ESHUTDOWN; } msg->actual_length = 0; msg->status = -EINPROGRESS; msg->state = START_STATE; list_add_tail(&msg->queue, &drv_data->queue); if (drv_data->run == QUEUE_RUNNING && !drv_data->busy) queue_work(drv_data->workqueue, &drv_data->pump_messages); spin_unlock_irqrestore(&drv_data->lock, flags); return 0; } /* the spi->mode bits understood by this driver: */ #define MODEBITS (SPI_CPOL | SPI_CPHA) static int setup(struct spi_device *spi) { struct pxa2xx_spi_chip *chip_info = NULL; struct chip_data *chip; struct driver_data *drv_data = spi_master_get_devdata(spi->master); struct ssp_device *ssp = drv_data->ssp; unsigned int clk_div; if (!spi->bits_per_word) spi->bits_per_word = 8; if (drv_data->ssp_type != PXA25x_SSP && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) { dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d " "b/w not 4-32 for type non-PXA25x_SSP\n", drv_data->ssp_type, spi->bits_per_word); return -EINVAL; } else if (drv_data->ssp_type == PXA25x_SSP && (spi->bits_per_word < 4 || spi->bits_per_word > 16)) { dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d " "b/w not 4-16 for type PXA25x_SSP\n", drv_data->ssp_type, spi->bits_per_word); return -EINVAL; } if (spi->mode & ~MODEBITS) { dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n", spi->mode & ~MODEBITS); return -EINVAL; } /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (!chip) { chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) { dev_err(&spi->dev, "failed setup: can't allocate chip data\n"); return -ENOMEM; } chip->cs_control = null_cs_control; chip->enable_dma = 0; chip->timeout = 1000; chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1); chip->dma_burst_size = drv_data->master_info->enable_dma ? DCMD_BURST8 : 0; } /* protocol drivers may change the chip settings, so... * if chip_info exists, use it */ chip_info = spi->controller_data; /* chip_info isn't always needed */ chip->cr1 = 0; if (chip_info) { if (chip_info->cs_control) chip->cs_control = chip_info->cs_control; chip->timeout = chip_info->timeout; chip->threshold = (SSCR1_RxTresh(chip_info->rx_threshold) & SSCR1_RFT) | (SSCR1_TxTresh(chip_info->tx_threshold) & SSCR1_TFT); chip->enable_dma = chip_info->dma_burst_size != 0 && drv_data->master_info->enable_dma; chip->dma_threshold = 0; if (chip_info->enable_loopback) chip->cr1 = SSCR1_LBM; } /* set dma burst and threshold outside of chip_info path so that if * chip_info goes away after setting chip->enable_dma, the * burst and threshold can still respond to changes in bits_per_word */ if (chip->enable_dma) { /* set up legal burst and threshold for dma */ if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word, &chip->dma_burst_size, &chip->dma_threshold)) { dev_warn(&spi->dev, "in setup: DMA burst size reduced " "to match bits_per_word\n"); } } clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz); chip->speed_hz = spi->max_speed_hz; chip->cr0 = clk_div | SSCR0_Motorola | SSCR0_DataSize(spi->bits_per_word > 16 ? spi->bits_per_word - 16 : spi->bits_per_word) | SSCR0_SSE | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0); chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH); chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0) | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0); /* NOTE: PXA25x_SSP _could_ use external clocking ... */ if (drv_data->ssp_type != PXA25x_SSP) dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n", spi->bits_per_word, clk_get_rate(ssp->clk) / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)), spi->mode & 0x3); else dev_dbg(&spi->dev, "%d bits/word, %ld Hz, mode %d\n", spi->bits_per_word, clk_get_rate(ssp->clk) / (1 + ((chip->cr0 & SSCR0_SCR) >> 8)), spi->mode & 0x3); if (spi->bits_per_word <= 8) { chip->n_bytes = 1; chip->dma_width = DCMD_WIDTH1; chip->read = u8_reader; chip->write = u8_writer; } else if (spi->bits_per_word <= 16) { chip->n_bytes = 2; chip->dma_width = DCMD_WIDTH2; chip->read = u16_reader; chip->write = u16_writer; } else if (spi->bits_per_word <= 32) { chip->cr0 |= SSCR0_EDSS; chip->n_bytes = 4; chip->dma_width = DCMD_WIDTH4; chip->read = u32_reader; chip->write = u32_writer; } else { dev_err(&spi->dev, "invalid wordsize\n"); return -ENODEV; } chip->bits_per_word = spi->bits_per_word; spi_set_ctldata(spi, chip); return 0; } static void cleanup(struct spi_device *spi) { struct chip_data *chip = spi_get_ctldata(spi); kfree(chip); } static int __init init_queue(struct driver_data *drv_data) { INIT_LIST_HEAD(&drv_data->queue); spin_lock_init(&drv_data->lock); drv_data->run = QUEUE_STOPPED; drv_data->busy = 0; tasklet_init(&drv_data->pump_transfers, pump_transfers, (unsigned long)drv_data); INIT_WORK(&drv_data->pump_messages, pump_messages); drv_data->workqueue = create_singlethread_workqueue( drv_data->master->dev.parent->bus_id); if (drv_data->workqueue == NULL) return -EBUSY; return 0; } static int start_queue(struct driver_data *drv_data) { unsigned long flags; spin_lock_irqsave(&drv_data->lock, flags); if (drv_data->run == QUEUE_RUNNING || drv_data->busy) { spin_unlock_irqrestore(&drv_data->lock, flags); return -EBUSY; } drv_data->run = QUEUE_RUNNING; drv_data->cur_msg = NULL; drv_data->cur_transfer = NULL; drv_data->cur_chip = NULL; spin_unlock_irqrestore(&drv_data->lock, flags); queue_work(drv_data->workqueue, &drv_data->pump_messages); return 0; } static int stop_queue(struct driver_data *drv_data) { unsigned long flags; unsigned limit = 500; int status = 0; spin_lock_irqsave(&drv_data->lock, flags); /* This is a bit lame, but is optimized for the common execution path. * A wait_queue on the drv_data->busy could be used, but then the common * execution path (pump_messages) would be required to call wake_up or * friends on every SPI message. Do this instead */ drv_data->run = QUEUE_STOPPED; while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) { spin_unlock_irqrestore(&drv_data->lock, flags); msleep(10); spin_lock_irqsave(&drv_data->lock, flags); } if (!list_empty(&drv_data->queue) || drv_data->busy) status = -EBUSY; spin_unlock_irqrestore(&drv_data->lock, flags); return status; } static int destroy_queue(struct driver_data *drv_data) { int status; status = stop_queue(drv_data); /* we are unloading the module or failing to load (only two calls * to this routine), and neither call can handle a return value. * However, destroy_workqueue calls flush_workqueue, and that will * block until all work is done. If the reason that stop_queue * timed out is that the work will never finish, then it does no * good to call destroy_workqueue, so return anyway. */ if (status != 0) return status; destroy_workqueue(drv_data->workqueue); return 0; } static int __init pxa2xx_spi_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct pxa2xx_spi_master *platform_info; struct spi_master *master; struct driver_data *drv_data = NULL; struct ssp_device *ssp; int status = 0; platform_info = dev->platform_data; ssp = ssp_request(pdev->id, pdev->name); if (ssp == NULL) { dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id); return -ENODEV; } /* Allocate master with space for drv_data and null dma buffer */ master = spi_alloc_master(dev, sizeof(struct driver_data) + 16); if (!master) { dev_err(&pdev->dev, "can not alloc spi_master\n"); ssp_free(ssp); return -ENOMEM; } drv_data = spi_master_get_devdata(master); drv_data->master = master; drv_data->master_info = platform_info; drv_data->pdev = pdev; drv_data->ssp = ssp; master->bus_num = pdev->id; master->num_chipselect = platform_info->num_chipselect; master->cleanup = cleanup; master->setup = setup; master->transfer = transfer; drv_data->ssp_type = ssp->type; drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data + sizeof(struct driver_data)), 8); drv_data->ioaddr = ssp->mmio_base; drv_data->ssdr_physical = ssp->phys_base + SSDR; if (ssp->type == PXA25x_SSP) { drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE; drv_data->dma_cr1 = 0; drv_data->clear_sr = SSSR_ROR; drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR; } else { drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE; drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE; drv_data->clear_sr = SSSR_ROR | SSSR_TINT; drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR; } status = request_irq(ssp->irq, ssp_int, 0, dev->bus_id, drv_data); if (status < 0) { dev_err(&pdev->dev, "can not get IRQ\n"); goto out_error_master_alloc; } /* Setup DMA if requested */ drv_data->tx_channel = -1; drv_data->rx_channel = -1; if (platform_info->enable_dma) { /* Get two DMA channels (rx and tx) */ drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx", DMA_PRIO_HIGH, dma_handler, drv_data); if (drv_data->rx_channel < 0) { dev_err(dev, "problem (%d) requesting rx channel\n", drv_data->rx_channel); status = -ENODEV; goto out_error_irq_alloc; } drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx", DMA_PRIO_MEDIUM, dma_handler, drv_data); if (drv_data->tx_channel < 0) { dev_err(dev, "problem (%d) requesting tx channel\n", drv_data->tx_channel); status = -ENODEV; goto out_error_dma_alloc; } DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel; DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel; } /* Enable SOC clock */ clk_enable(ssp->clk); /* Load default SSP configuration */ write_SSCR0(0, drv_data->ioaddr); write_SSCR1(SSCR1_RxTresh(4) | SSCR1_TxTresh(12), drv_data->ioaddr); write_SSCR0(SSCR0_SerClkDiv(2) | SSCR0_Motorola | SSCR0_DataSize(8), drv_data->ioaddr); if (drv_data->ssp_type != PXA25x_SSP) write_SSTO(0, drv_data->ioaddr); write_SSPSP(0, drv_data->ioaddr); /* Initial and start queue */ status = init_queue(drv_data); if (status != 0) { dev_err(&pdev->dev, "problem initializing queue\n"); goto out_error_clock_enabled; } status = start_queue(drv_data); if (status != 0) { dev_err(&pdev->dev, "problem starting queue\n"); goto out_error_clock_enabled; } /* Register with the SPI framework */ platform_set_drvdata(pdev, drv_data); status = spi_register_master(master); if (status != 0) { dev_err(&pdev->dev, "problem registering spi master\n"); goto out_error_queue_alloc; } return status; out_error_queue_alloc: destroy_queue(drv_data); out_error_clock_enabled: clk_disable(ssp->clk); out_error_dma_alloc: if (drv_data->tx_channel != -1) pxa_free_dma(drv_data->tx_channel); if (drv_data->rx_channel != -1) pxa_free_dma(drv_data->rx_channel); out_error_irq_alloc: free_irq(ssp->irq, drv_data); out_error_master_alloc: spi_master_put(master); ssp_free(ssp); return status; } static int pxa2xx_spi_remove(struct platform_device *pdev) { struct driver_data *drv_data = platform_get_drvdata(pdev); struct ssp_device *ssp = drv_data->ssp; int status = 0; if (!drv_data) return 0; /* Remove the queue */ status = destroy_queue(drv_data); if (status != 0) /* the kernel does not check the return status of this * this routine (mod->exit, within the kernel). Therefore * nothing is gained by returning from here, the module is * going away regardless, and we should not leave any more * resources allocated than necessary. We cannot free the * message memory in drv_data->queue, but we can release the * resources below. I think the kernel should honor -EBUSY * returns but... */ dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not " "complete, message memory not freed\n"); /* Disable the SSP at the peripheral and SOC level */ write_SSCR0(0, drv_data->ioaddr); clk_disable(ssp->clk); /* Release DMA */ if (drv_data->master_info->enable_dma) { DRCMR(ssp->drcmr_rx) = 0; DRCMR(ssp->drcmr_tx) = 0; pxa_free_dma(drv_data->tx_channel); pxa_free_dma(drv_data->rx_channel); } /* Release IRQ */ free_irq(ssp->irq, drv_data); /* Release SSP */ ssp_free(ssp); /* Disconnect from the SPI framework */ spi_unregister_master(drv_data->master); /* Prevent double remove */ platform_set_drvdata(pdev, NULL); return 0; } static void pxa2xx_spi_shutdown(struct platform_device *pdev) { int status = 0; if ((status = pxa2xx_spi_remove(pdev)) != 0) dev_err(&pdev->dev, "shutdown failed with %d\n", status); } #ifdef CONFIG_PM static int pxa2xx_spi_suspend(struct platform_device *pdev, pm_message_t state) { struct driver_data *drv_data = platform_get_drvdata(pdev); struct ssp_device *ssp = drv_data->ssp; int status = 0; status = stop_queue(drv_data); if (status != 0) return status; write_SSCR0(0, drv_data->ioaddr); clk_disable(ssp->clk); return 0; } static int pxa2xx_spi_resume(struct platform_device *pdev) { struct driver_data *drv_data = platform_get_drvdata(pdev); struct ssp_device *ssp = drv_data->ssp; int status = 0; /* Enable the SSP clock */ clk_enable(ssp->clk); /* Start the queue running */ status = start_queue(drv_data); if (status != 0) { dev_err(&pdev->dev, "problem starting queue (%d)\n", status); return status; } return 0; } #else #define pxa2xx_spi_suspend NULL #define pxa2xx_spi_resume NULL #endif /* CONFIG_PM */ static struct platform_driver driver = { .driver = { .name = "pxa2xx-spi", .owner = THIS_MODULE, }, .remove = pxa2xx_spi_remove, .shutdown = pxa2xx_spi_shutdown, .suspend = pxa2xx_spi_suspend, .resume = pxa2xx_spi_resume, }; static int __init pxa2xx_spi_init(void) { return platform_driver_probe(&driver, pxa2xx_spi_probe); } module_init(pxa2xx_spi_init); static void __exit pxa2xx_spi_exit(void) { platform_driver_unregister(&driver); } module_exit(pxa2xx_spi_exit);