diff options
Diffstat (limited to 'drivers/spi/omap2_mcspi.c')
| -rw-r--r-- | drivers/spi/omap2_mcspi.c | 1081 |
1 files changed, 1081 insertions, 0 deletions
diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c new file mode 100644 index 00000000000..6b357cdb9ea --- /dev/null +++ b/drivers/spi/omap2_mcspi.c @@ -0,0 +1,1081 @@ +/* + * OMAP2 McSPI controller driver + * + * Copyright (C) 2005, 2006 Nokia Corporation + * Author: Samuel Ortiz <samuel.ortiz@nokia.com> and + * Juha Yrjölä <juha.yrjola@nokia.com> + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include <linux/spi/spi.h> + +#include <asm/arch/dma.h> +#include <asm/arch/clock.h> + + +#define OMAP2_MCSPI_MAX_FREQ 48000000 + +#define OMAP2_MCSPI_REVISION 0x00 +#define OMAP2_MCSPI_SYSCONFIG 0x10 +#define OMAP2_MCSPI_SYSSTATUS 0x14 +#define OMAP2_MCSPI_IRQSTATUS 0x18 +#define OMAP2_MCSPI_IRQENABLE 0x1c +#define OMAP2_MCSPI_WAKEUPENABLE 0x20 +#define OMAP2_MCSPI_SYST 0x24 +#define OMAP2_MCSPI_MODULCTRL 0x28 + +/* per-channel banks, 0x14 bytes each, first is: */ +#define OMAP2_MCSPI_CHCONF0 0x2c +#define OMAP2_MCSPI_CHSTAT0 0x30 +#define OMAP2_MCSPI_CHCTRL0 0x34 +#define OMAP2_MCSPI_TX0 0x38 +#define OMAP2_MCSPI_RX0 0x3c + +/* per-register bitmasks: */ + +#define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE (1 << 0) +#define OMAP2_MCSPI_SYSCONFIG_SOFTRESET (1 << 1) + +#define OMAP2_MCSPI_SYSSTATUS_RESETDONE (1 << 0) + +#define OMAP2_MCSPI_MODULCTRL_SINGLE (1 << 0) +#define OMAP2_MCSPI_MODULCTRL_MS (1 << 2) +#define OMAP2_MCSPI_MODULCTRL_STEST (1 << 3) + +#define OMAP2_MCSPI_CHCONF_PHA (1 << 0) +#define OMAP2_MCSPI_CHCONF_POL (1 << 1) +#define OMAP2_MCSPI_CHCONF_CLKD_MASK (0x0f << 2) +#define OMAP2_MCSPI_CHCONF_EPOL (1 << 6) +#define OMAP2_MCSPI_CHCONF_WL_MASK (0x1f << 7) +#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY (0x01 << 12) +#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY (0x02 << 12) +#define OMAP2_MCSPI_CHCONF_TRM_MASK (0x03 << 12) +#define OMAP2_MCSPI_CHCONF_DMAW (1 << 14) +#define OMAP2_MCSPI_CHCONF_DMAR (1 << 15) +#define OMAP2_MCSPI_CHCONF_DPE0 (1 << 16) +#define OMAP2_MCSPI_CHCONF_DPE1 (1 << 17) +#define OMAP2_MCSPI_CHCONF_IS (1 << 18) +#define OMAP2_MCSPI_CHCONF_TURBO (1 << 19) +#define OMAP2_MCSPI_CHCONF_FORCE (1 << 20) + +#define OMAP2_MCSPI_CHSTAT_RXS (1 << 0) +#define OMAP2_MCSPI_CHSTAT_TXS (1 << 1) +#define OMAP2_MCSPI_CHSTAT_EOT (1 << 2) + +#define OMAP2_MCSPI_CHCTRL_EN (1 << 0) + + +/* We have 2 DMA channels per CS, one for RX and one for TX */ +struct omap2_mcspi_dma { + int dma_tx_channel; + int dma_rx_channel; + + int dma_tx_sync_dev; + int dma_rx_sync_dev; + + struct completion dma_tx_completion; + struct completion dma_rx_completion; +}; + +/* use PIO for small transfers, avoiding DMA setup/teardown overhead and + * cache operations; better heuristics consider wordsize and bitrate. + */ +#define DMA_MIN_BYTES 8 + + +struct omap2_mcspi { + struct work_struct work; + /* lock protects queue and registers */ + spinlock_t lock; + struct list_head msg_queue; + struct spi_master *master; + struct clk *ick; + struct clk *fck; + /* Virtual base address of the controller */ + void __iomem *base; + /* SPI1 has 4 channels, while SPI2 has 2 */ + struct omap2_mcspi_dma *dma_channels; +}; + +struct omap2_mcspi_cs { + void __iomem *base; + int word_len; +}; + +static struct workqueue_struct *omap2_mcspi_wq; + +#define MOD_REG_BIT(val, mask, set) do { \ + if (set) \ + val |= mask; \ + else \ + val &= ~mask; \ +} while (0) + +static inline void mcspi_write_reg(struct spi_master *master, + int idx, u32 val) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + + __raw_writel(val, mcspi->base + idx); +} + +static inline u32 mcspi_read_reg(struct spi_master *master, int idx) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + + return __raw_readl(mcspi->base + idx); +} + +static inline void mcspi_write_cs_reg(const struct spi_device *spi, + int idx, u32 val) +{ + struct omap2_mcspi_cs *cs = spi->controller_state; + + __raw_writel(val, cs->base + idx); +} + +static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx) +{ + struct omap2_mcspi_cs *cs = spi->controller_state; + + return __raw_readl(cs->base + idx); +} + +static void omap2_mcspi_set_dma_req(const struct spi_device *spi, + int is_read, int enable) +{ + u32 l, rw; + + l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); + + if (is_read) /* 1 is read, 0 write */ + rw = OMAP2_MCSPI_CHCONF_DMAR; + else + rw = OMAP2_MCSPI_CHCONF_DMAW; + + MOD_REG_BIT(l, rw, enable); + mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l); +} + +static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) +{ + u32 l; + + l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0; + mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l); +} + +static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active) +{ + u32 l; + + l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); + MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active); + mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l); +} + +static void omap2_mcspi_set_master_mode(struct spi_master *master) +{ + u32 l; + + /* setup when switching from (reset default) slave mode + * to single-channel master mode + */ + l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL); + MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0); + MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0); + MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1); + mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l); +} + +static unsigned +omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) +{ + struct omap2_mcspi *mcspi; + struct omap2_mcspi_cs *cs = spi->controller_state; + struct omap2_mcspi_dma *mcspi_dma; + unsigned int count, c; + unsigned long base, tx_reg, rx_reg; + int word_len, data_type, element_count; + u8 * rx; + const u8 * tx; + + mcspi = spi_master_get_devdata(spi->master); + mcspi_dma = &mcspi->dma_channels[spi->chip_select]; + + count = xfer->len; + c = count; + word_len = cs->word_len; + + base = (unsigned long) io_v2p(cs->base); + tx_reg = base + OMAP2_MCSPI_TX0; + rx_reg = base + OMAP2_MCSPI_RX0; + rx = xfer->rx_buf; + tx = xfer->tx_buf; + + if (word_len <= 8) { + data_type = OMAP_DMA_DATA_TYPE_S8; + element_count = count; + } else if (word_len <= 16) { + data_type = OMAP_DMA_DATA_TYPE_S16; + element_count = count >> 1; + } else /* word_len <= 32 */ { + data_type = OMAP_DMA_DATA_TYPE_S32; + element_count = count >> 2; + } + + if (tx != NULL) { + omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel, + data_type, element_count, 1, + OMAP_DMA_SYNC_ELEMENT, + mcspi_dma->dma_tx_sync_dev, 0); + + omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + tx_reg, 0, 0); + + omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0, + OMAP_DMA_AMODE_POST_INC, + xfer->tx_dma, 0, 0); + } + + if (rx != NULL) { + omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel, + data_type, element_count, 1, + OMAP_DMA_SYNC_ELEMENT, + mcspi_dma->dma_rx_sync_dev, 1); + + omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + rx_reg, 0, 0); + + omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0, + OMAP_DMA_AMODE_POST_INC, + xfer->rx_dma, 0, 0); + } + + if (tx != NULL) { + omap_start_dma(mcspi_dma->dma_tx_channel); + omap2_mcspi_set_dma_req(spi, 0, 1); + } + + if (rx != NULL) { + omap_start_dma(mcspi_dma->dma_rx_channel); + omap2_mcspi_set_dma_req(spi, 1, 1); + } + + if (tx != NULL) { + wait_for_completion(&mcspi_dma->dma_tx_completion); + dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE); + } + + if (rx != NULL) { + wait_for_completion(&mcspi_dma->dma_rx_completion); + dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE); + } + return count; +} + +static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit) +{ + unsigned long timeout; + + timeout = jiffies + msecs_to_jiffies(1000); + while (!(__raw_readl(reg) & bit)) { + if (time_after(jiffies, timeout)) + return -1; + cpu_relax(); + } + return 0; +} + +static unsigned +omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) +{ + struct omap2_mcspi *mcspi; + struct omap2_mcspi_cs *cs = spi->controller_state; + unsigned int count, c; + u32 l; + void __iomem *base = cs->base; + void __iomem *tx_reg; + void __iomem *rx_reg; + void __iomem *chstat_reg; + int word_len; + + mcspi = spi_master_get_devdata(spi->master); + count = xfer->len; + c = count; + word_len = cs->word_len; + + l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); + l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; + + /* We store the pre-calculated register addresses on stack to speed + * up the transfer loop. */ + tx_reg = base + OMAP2_MCSPI_TX0; + rx_reg = base + OMAP2_MCSPI_RX0; + chstat_reg = base + OMAP2_MCSPI_CHSTAT0; + + if (word_len <= 8) { + u8 *rx; + const u8 *tx; + + rx = xfer->rx_buf; + tx = xfer->tx_buf; + + do { + if (tx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_TXS) < 0) { + dev_err(&spi->dev, "TXS timed out\n"); + goto out; + } +#ifdef VERBOSE + dev_dbg(&spi->dev, "write-%d %02x\n", + word_len, *tx); +#endif + __raw_writel(*tx++, tx_reg); + } + if (rx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_RXS) < 0) { + dev_err(&spi->dev, "RXS timed out\n"); + goto out; + } + /* prevent last RX_ONLY read from triggering + * more word i/o: switch to rx+tx + */ + if (c == 0 && tx == NULL) + mcspi_write_cs_reg(spi, + OMAP2_MCSPI_CHCONF0, l); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %02x\n", + word_len, *(rx - 1)); +#endif + } + c -= 1; + } while (c); + } else if (word_len <= 16) { + u16 *rx; + const u16 *tx; + + rx = xfer->rx_buf; + tx = xfer->tx_buf; + do { + if (tx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_TXS) < 0) { + dev_err(&spi->dev, "TXS timed out\n"); + goto out; + } +#ifdef VERBOSE + dev_dbg(&spi->dev, "write-%d %04x\n", + word_len, *tx); +#endif + __raw_writel(*tx++, tx_reg); + } + if (rx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_RXS) < 0) { + dev_err(&spi->dev, "RXS timed out\n"); + goto out; + } + /* prevent last RX_ONLY read from triggering + * more word i/o: switch to rx+tx + */ + if (c == 0 && tx == NULL) + mcspi_write_cs_reg(spi, + OMAP2_MCSPI_CHCONF0, l); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %04x\n", + word_len, *(rx - 1)); +#endif + } + c -= 2; + } while (c); + } else if (word_len <= 32) { + u32 *rx; + const u32 *tx; + + rx = xfer->rx_buf; + tx = xfer->tx_buf; + do { + if (tx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_TXS) < 0) { + dev_err(&spi->dev, "TXS timed out\n"); + goto out; + } +#ifdef VERBOSE + dev_dbg(&spi->dev, "write-%d %04x\n", + word_len, *tx); +#endif + __raw_writel(*tx++, tx_reg); + } + if (rx != NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_RXS) < 0) { + dev_err(&spi->dev, "RXS timed out\n"); + goto out; + } + /* prevent last RX_ONLY read from triggering + * more word i/o: switch to rx+tx + */ + if (c == 0 && tx == NULL) + mcspi_write_cs_reg(spi, + OMAP2_MCSPI_CHCONF0, l); + *rx++ = __raw_readl(rx_reg); +#ifdef VERBOSE + dev_dbg(&spi->dev, "read-%d %04x\n", + word_len, *(rx - 1)); +#endif + } + c -= 4; + } while (c); + } + + /* for TX_ONLY mode, be sure all words have shifted out */ + if (xfer->rx_buf == NULL) { + if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_TXS) < 0) { + dev_err(&spi->dev, "TXS timed out\n"); + } else if (mcspi_wait_for_reg_bit(chstat_reg, + OMAP2_MCSPI_CHSTAT_EOT) < 0) + dev_err(&spi->dev, "EOT timed out\n"); + } +out: + return count - c; +} + +/* called only when no transfer is active to this device */ +static int omap2_mcspi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + struct omap2_mcspi_cs *cs = spi->controller_state; + struct omap2_mcspi *mcspi; + u32 l = 0, div = 0; + u8 word_len = spi->bits_per_word; + + mcspi = spi_master_get_devdata(spi->master); + + if (t != NULL && t->bits_per_word) + word_len = t->bits_per_word; + + cs->word_len = word_len; + + if (spi->max_speed_hz) { + while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div)) + > spi->max_speed_hz) + div++; + } else + div = 15; + + l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); + + /* standard 4-wire master mode: SCK, MOSI/out, MISO/in, nCS + * REVISIT: this controller could support SPI_3WIRE mode. + */ + l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1); + l |= OMAP2_MCSPI_CHCONF_DPE0; + + /* wordlength */ + l &= ~OMAP2_MCSPI_CHCONF_WL_MASK; + l |= (word_len - 1) << 7; + + /* set chipselect polarity; manage with FORCE */ + if (!(spi->mode & SPI_CS_HIGH)) + l |= OMAP2_MCSPI_CHCONF_EPOL; /* active-low; normal */ + else + l &= ~OMAP2_MCSPI_CHCONF_EPOL; + + /* set clock divisor */ + l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK; + l |= div << 2; + + /* set SPI mode 0..3 */ + if (spi->mode & SPI_CPOL) + l |= OMAP2_MCSPI_CHCONF_POL; + else + l &= ~OMAP2_MCSPI_CHCONF_POL; + if (spi->mode & SPI_CPHA) + l |= OMAP2_MCSPI_CHCONF_PHA; + else + l &= ~OMAP2_MCSPI_CHCONF_PHA; + + mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l); + + dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n", + OMAP2_MCSPI_MAX_FREQ / (1 << div), + (spi->mode & SPI_CPHA) ? "trailing" : "leading", + (spi->mode & SPI_CPOL) ? "inverted" : "normal"); + + return 0; +} + +static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data) +{ + struct spi_device *spi = data; + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *mcspi_dma; + + mcspi = spi_master_get_devdata(spi->master); + mcspi_dma = &(mcspi->dma_channels[spi->chip_select]); + + complete(&mcspi_dma->dma_rx_completion); + + /* We must disable the DMA RX request */ + omap2_mcspi_set_dma_req(spi, 1, 0); +} + +static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data) +{ + struct spi_device *spi = data; + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *mcspi_dma; + + mcspi = spi_master_get_devdata(spi->master); + mcspi_dma = &(mcspi->dma_channels[spi->chip_select]); + + complete(&mcspi_dma->dma_tx_completion); + + /* We must disable the DMA TX request */ + omap2_mcspi_set_dma_req(spi, 0, 0); +} + +static int omap2_mcspi_request_dma(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *mcspi_dma; + + mcspi = spi_master_get_devdata(master); + mcspi_dma = mcspi->dma_channels + spi->chip_select; + + if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX", + omap2_mcspi_dma_rx_callback, spi, + &mcspi_dma->dma_rx_channel)) { + dev_err(&spi->dev, "no RX DMA channel for McSPI\n"); + return -EAGAIN; + } + + if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX", + omap2_mcspi_dma_tx_callback, spi, + &mcspi_dma->dma_tx_channel)) { + omap_free_dma(mcspi_dma->dma_rx_channel); + mcspi_dma->dma_rx_channel = -1; + dev_err(&spi->dev, "no TX DMA channel for McSPI\n"); + return -EAGAIN; + } + + init_completion(&mcspi_dma->dma_rx_completion); + init_completion(&mcspi_dma->dma_tx_completion); + + return 0; +} + +/* the spi->mode bits understood by this driver: */ +#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH) + +static int omap2_mcspi_setup(struct spi_device *spi) +{ + int ret; + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *mcspi_dma; + struct omap2_mcspi_cs *cs = spi->controller_state; + + if (spi->mode & ~MODEBITS) { + dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n", + spi->mode & ~MODEBITS); + return -EINVAL; + } + + if (spi->bits_per_word == 0) + spi->bits_per_word = 8; + else if (spi->bits_per_word < 4 || spi->bits_per_word > 32) { + dev_dbg(&spi->dev, "setup: unsupported %d bit words\n", + spi->bits_per_word); + return -EINVAL; + } + + mcspi = spi_master_get_devdata(spi->master); + mcspi_dma = &mcspi->dma_channels[spi->chip_select]; + + if (!cs) { + cs = kzalloc(sizeof *cs, GFP_KERNEL); + if (!cs) + return -ENOMEM; + cs->base = mcspi->base + spi->chip_select * 0x14; + spi->controller_state = cs; + } + + if (mcspi_dma->dma_rx_channel == -1 + || mcspi_dma->dma_tx_channel == -1) { + ret = omap2_mcspi_request_dma(spi); + if (ret < 0) + return ret; + } + + clk_enable(mcspi->ick); + clk_enable(mcspi->fck); + ret = omap2_mcspi_setup_transfer(spi, NULL); + clk_disable(mcspi->fck); + clk_disable(mcspi->ick); + + return ret; +} + +static void omap2_mcspi_cleanup(struct spi_device *spi) +{ + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *mcspi_dma; + + mcspi = spi_master_get_devdata(spi->master); + mcspi_dma = &mcspi->dma_channels[spi->chip_select]; + + kfree(spi->controller_state); + + if (mcspi_dma->dma_rx_channel != -1) { + omap_free_dma(mcspi_dma->dma_rx_channel); + mcspi_dma->dma_rx_channel = -1; + } + if (mcspi_dma->dma_tx_channel != -1) { + omap_free_dma(mcspi_dma->dma_tx_channel); + mcspi_dma->dma_tx_channel = -1; + } +} + +static void omap2_mcspi_work(struct work_struct *work) +{ + struct omap2_mcspi *mcspi; + + mcspi = container_of(work, struct omap2_mcspi, work); + spin_lock_irq(&mcspi->lock); + + clk_enable(mcspi->ick); + clk_enable(mcspi->fck); + + /* We only enable one channel at a time -- the one whose message is + * at the head of the queue -- although this controller would gladly + * arbitrate among multiple channels. This corresponds to "single + * channel" master mode. As a side effect, we need to manage the + * chipselect with the FORCE bit ... CS != channel enable. + */ + while (!list_empty(&mcspi->msg_queue)) { + struct spi_message *m; + struct spi_device *spi; + struct spi_transfer *t = NULL; + int cs_active = 0; + struct omap2_mcspi_device_config *conf; + struct omap2_mcspi_cs *cs; + int par_override = 0; + int status = 0; + u32 chconf; + + m = container_of(mcspi->msg_queue.next, struct spi_message, + queue); + + list_del_init(&m->queue); + spin_unlock_irq(&mcspi->lock); + + spi = m->spi; + conf = spi->controller_data; + cs = spi->controller_state; + + omap2_mcspi_set_enable(spi, 1); + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { + status = -EINVAL; + break; + } + if (par_override || t->speed_hz || t->bits_per_word) { + par_override = 1; + status = omap2_mcspi_setup_transfer(spi, t); + if (status < 0) + break; + if (!t->speed_hz && !t->bits_per_word) + par_override = 0; + } + + if (!cs_active) { + omap2_mcspi_force_cs(spi, 1); + cs_active = 1; + } + + chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0); + chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK; + if (t->tx_buf == NULL) + chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY; + else if (t->rx_buf == NULL) + chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; + mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, chconf); + + if (t->len) { + unsigned count; + + /* RX_ONLY mode needs dummy data in TX reg */ + if (t->tx_buf == NULL) + __raw_writel(0, cs->base + + OMAP2_MCSPI_TX0); + + if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES) + count = omap2_mcspi_txrx_dma(spi, t); + else + count = omap2_mcspi_txrx_pio(spi, t); + m->actual_length += count; + + if (count != t->len) { + status = -EIO; + break; + } + } + + if (t->delay_usecs) + udelay(t->delay_usecs); + + /* ignore the "leave it on after last xfer" hint */ + if (t->cs_change) { + omap2_mcspi_force_cs(spi, 0); + cs_active = 0; + } + } + + /* Restore defaults if they were overriden */ + if (par_override) { + par_override = 0; + status = omap2_mcspi_setup_transfer(spi, NULL); + } + + if (cs_active) + omap2_mcspi_force_cs(spi, 0); + + omap2_mcspi_set_enable(spi, 0); + + m->status = status; + m->complete(m->context); + + spin_lock_irq(&mcspi->lock); + } + + clk_disable(mcspi->fck); + clk_disable(mcspi->ick); + + spin_unlock_irq(&mcspi->lock); +} + +static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m) +{ + struct omap2_mcspi *mcspi; + unsigned long flags; + struct spi_transfer *t; + + m->actual_length = 0; + m->status = 0; + + /* reject invalid messages and transfers */ + if (list_empty(&m->transfers) || !m->complete) + return -EINVAL; + list_for_each_entry(t, &m->transfers, transfer_list) { + const void *tx_buf = t->tx_buf; + void *rx_buf = t->rx_buf; + unsigned len = t->len; + + if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ + || (len && !(rx_buf || tx_buf)) + || (t->bits_per_word && + ( t->bits_per_word < 4 + || t->bits_per_word > 32))) { + dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n", + t->speed_hz, + len, + tx_buf ? "tx" : "", + rx_buf ? "rx" : "", + t->bits_per_word); + return -EINVAL; + } + if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) { + dev_dbg(&spi->dev, "%d Hz max exceeds %d\n", + t->speed_hz, + OMAP2_MCSPI_MAX_FREQ/(1<<16)); + return -EINVAL; + } + + if (m->is_dma_mapped || len < DMA_MIN_BYTES) + continue; + + /* Do DMA mapping "early" for better error reporting and + * dcache use. Note that if dma_unmap_single() ever starts + * to do real work on ARM, we'd need to clean up mappings + * for previous transfers on *ALL* exits of this loop... + */ + if (tx_buf != NULL) { + t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf, + len, DMA_TO_DEVICE); + if (dma_mapping_error(t->tx_dma)) { + dev_dbg(&spi->dev, "dma %cX %d bytes error\n", + 'T', len); + return -EINVAL; + } + } + if (rx_buf != NULL) { + t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len, + DMA_FROM_DEVICE); + if (dma_mapping_error(t->rx_dma)) { + dev_dbg(&spi->dev, "dma %cX %d bytes error\n", + 'R', len); + if (tx_buf != NULL) + dma_unmap_single(NULL, t->tx_dma, + len, DMA_TO_DEVICE); + return -EINVAL; + } + } + } + + mcspi = spi_master_get_devdata(spi->master); + + spin_lock_irqsave(&mcspi->lock, flags); + list_add_tail(&m->queue, &mcspi->msg_queue); + queue_work(omap2_mcspi_wq, &mcspi->work); + spin_unlock_irqrestore(&mcspi->lock, flags); + + return 0; +} + +static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi) +{ + struct spi_master *master = mcspi->master; + u32 tmp; + + clk_enable(mcspi->ick); + clk_enable(mcspi->fck); + + mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, + OMAP2_MCSPI_SYSCONFIG_SOFTRESET); + do { + tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS); + } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE)); + + mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG, + /* (3 << 8) | (2 << 3) | */ + OMAP2_MCSPI_SYSCONFIG_AUTOIDLE); + + omap2_mcspi_set_master_mode(master); + + clk_disable(mcspi->fck); + clk_disable(mcspi->ick); + return 0; +} + +static u8 __initdata spi1_rxdma_id [] = { + OMAP24XX_DMA_SPI1_RX0, + OMAP24XX_DMA_SPI1_RX1, + OMAP24XX_DMA_SPI1_RX2, + OMAP24XX_DMA_SPI1_RX3, +}; + +static u8 __initdata spi1_txdma_id [] = { + OMAP24XX_DMA_SPI1_TX0, + OMAP24XX_DMA_SPI1_TX1, + OMAP24XX_DMA_SPI1_TX2, + OMAP24XX_DMA_SPI1_TX3, +}; + +static u8 __initdata spi2_rxdma_id[] = { + OMAP24XX_DMA_SPI2_RX0, + OMAP24XX_DMA_SPI2_RX1, +}; + +static u8 __initdata spi2_txdma_id[] = { + OMAP24XX_DMA_SPI2_TX0, + OMAP24XX_DMA_SPI2_TX1, +}; + +static int __init omap2_mcspi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct omap2_mcspi *mcspi; + struct resource *r; + int status = 0, i; + const u8 *rxdma_id, *txdma_id; + unsigned num_chipselect; + + switch (pdev->id) { + case 1: + rxdma_id = spi1_rxdma_id; + txdma_id = spi1_txdma_id; + num_chipselect = 4; + break; + case 2: + rxdma_id = spi2_rxdma_id; + txdma_id = spi2_txdma_id; + num_chipselect = 2; + break; + /* REVISIT omap2430 has a third McSPI ... */ + default: + return -EINVAL; + } + + master = spi_alloc_master(&pdev->dev, sizeof *mcspi); + if (master == NULL) { + dev_dbg(&pdev->dev, "master allocation failed\n"); + return -ENOMEM; + } + + if (pdev->id != -1) + master->bus_num = pdev->id; + + master->setup = omap2_mcspi_setup; + master->transfer = omap2_mcspi_transfer; + master->cleanup = omap2_mcspi_cleanup; + master->num_chipselect = num_chipselect; + + dev_set_drvdata(&pdev->dev, master); + + mcspi = spi_master_get_devdata(master); + mcspi->master = master; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (r == NULL) { + status = -ENODEV; + goto err1; + } + if (!request_mem_region(r->start, (r->end - r->start) + 1, + pdev->dev.bus_id)) { + status = -EBUSY; + goto err1; + } + + mcspi->base = (void __iomem *) io_p2v(r->start); + + INIT_WORK(&mcspi->work, omap2_mcspi_work); + + spin_lock_init(&mcspi->lock); + INIT_LIST_HEAD(&mcspi->msg_queue); + + mcspi->ick = clk_get(&pdev->dev, "mcspi_ick"); + if (IS_ERR(mcspi->ick)) { + dev_dbg(&pdev->dev, "can't get mcspi_ick\n"); + status = PTR_ERR(mcspi->ick); + goto err1a; + } + mcspi->fck = clk_get(&pdev->dev, "mcspi_fck"); + if (IS_ERR(mcspi->fck)) { + dev_dbg(&pdev->dev, "can't get mcspi_fck\n"); + status = PTR_ERR(mcspi->fck); + goto err2; + } + + mcspi->dma_channels = kcalloc(master->num_chipselect, + sizeof(struct omap2_mcspi_dma), + GFP_KERNEL); + + if (mcspi->dma_channels == NULL) + goto err3; + + for (i = 0; i < num_chipselect; i++) { + mcspi->dma_channels[i].dma_rx_channel = -1; + mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i]; + mcspi->dma_channels[i].dma_tx_channel = -1; + mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i]; + } + + if (omap2_mcspi_reset(mcspi) < 0) + goto err4; + + status = spi_register_master(master); + if (status < 0) + goto err4; + + return status; + +err4: + kfree(mcspi->dma_channels); +err3: + clk_put(mcspi->fck); +err2: + clk_put(mcspi->ick); +err1a: + release_mem_region(r->start, (r->end - r->start) + 1); +err1: + spi_master_put(master); + return status; +} + +static int __exit omap2_mcspi_remove(struct platform_device *pdev) +{ + struct spi_master *master; + struct omap2_mcspi *mcspi; + struct omap2_mcspi_dma *dma_channels; + struct resource *r; + + master = dev_get_drvdata(&pdev->dev); + mcspi = spi_master_get_devdata(master); + dma_channels = mcspi->dma_channels; + + clk_put(mcspi->fck); + clk_put(mcspi->ick); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + release_mem_region(r->start, (r->end - r->start) + 1); + + spi_unregister_master(master); + kfree(dma_channels); + + return 0; +} + +static struct platform_driver omap2_mcspi_driver = { + .driver = { + .name = "omap2_mcspi", + .owner = THIS_MODULE, + }, + .remove = __exit_p(omap2_mcspi_remove), +}; + + +static int __init omap2_mcspi_init(void) +{ + omap2_mcspi_wq = create_singlethread_workqueue( + omap2_mcspi_driver.driver.name); + if (omap2_mcspi_wq == NULL) + return -1; + return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe); +} +subsys_initcall(omap2_mcspi_init); + +static void __exit omap2_mcspi_exit(void) +{ + platform_driver_unregister(&omap2_mcspi_driver); + + destroy_workqueue(omap2_mcspi_wq); +} +module_exit(omap2_mcspi_exit); + +MODULE_LICENSE("GPL"); |