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path: root/drivers/spi/omap2_mcspi.c
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Diffstat (limited to 'drivers/spi/omap2_mcspi.c')
-rw-r--r--drivers/spi/omap2_mcspi.c1081
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 000000000000..6b357cdb9ea3
--- /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");
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-26 18:24:39 +0300