Re: [PATCH][RFC] McSPI Slave and DMA,FIFO support

"Hemanth V" <hemanthv@xxxxxx> · Mon, 18 May 2009 13:01:57 +0530

----- Original Message ----- 
From: "Kevin Hilman" <khilman@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [PATCH][RFC] McSPI Slave and DMA,FIFO support


"Hemanth V" <hemanthv@xxxxxx> writes:

This patch adds support for McSPI slave and FIFO. DMA and FIFO
could be enabled together for better throughput. Platform config
parameters have been added to enable these features on any particular
McSPI controller.

FIFO can be enabled by defining fifo_depth parameter. fifo_depth needs
to be a multiple of buffer size that is used for read/write.

These features are useful when you have high throughput devices
like WLAN or Modem connected over SPI.

Signed-off-by: Hemanth V <hemanthv@xxxxxx>

---
 arch/arm/mach-omap2/board-3430sdp.c     |   19 +
 arch/arm/mach-omap2/devices.c           |   16 +
 arch/arm/mach-omap2/mux.c               |   11
 arch/arm/plat-omap/include/mach/mcspi.h |   13 +
 arch/arm/plat-omap/include/mach/mux.h   |    7
 drivers/spi/omap2_mcspi.c               |  353 
++++++++++++++++++++++++++++----
 6 files changed, 379 insertions(+), 40 deletions(-)

I think you should break this up into a series:

1) SPI driver changes (which could go upstream after review/approval)
2) mux changes
3) OMAP init changes (devices.c)
4) SDP changes, which are debug only

Where (2) and (3) could probably be combined.


Yes, will create a series of 3 patches.




Index: linux-omap-2.6/arch/arm/mach-omap2/board-3430sdp.c
===================================================================

--- linux-omap-2.6.orig/arch/arm/mach-omap2/board-3430sdp.c 2009-05-14
12:38:50.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/board-3430sdp.c 2009-05-14
19:48:35.000000000 +0530
@@ -228,6 +228,13 @@
 .single_channel = 1, /* 0: slave, 1: master */
 };

+#ifdef CONFIG_SPI_DEBUG
+static struct omap2_mcspi_device_config dummy_mcspi_config = {
+ .turbo_mode = 0,
+ .single_channel = 1,  /* 0: slave, 1: master */
+};
+#endif
+
 static struct spi_board_info sdp3430_spi_board_info[] __initdata = {
 [0] = {
 /*
@@ -242,6 +249,18 @@
 .irq = 0,
 .platform_data = &tsc2046_config,
 },
+#ifdef CONFIG_SPI_DEBUG
+ [1] = {
+ /* SPI test driver attached to SPI2 controller by
+ * default
+ */
+ .modalias = "spitst",
+ .bus_num = 2,
+ .chip_select = 0,
+ .max_speed_hz = 1500000,
+ .controller_data = &dummy_mcspi_config,
+ },
+#endif
 };

 static struct platform_device sdp3430_lcd_device = {
Index: linux-omap-2.6/arch/arm/mach-omap2/devices.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/devices.c 2009-05-14
12:38:50.000000000 +0530
+++ linux-omap-2.6/arch/arm/mach-omap2/devices.c 2009-05-15 
16:53:38.000000000
+0530
@@ -257,8 +257,12 @@
 #define OMAP2_MCSPI3_BASE 0x480b8000
 #define OMAP2_MCSPI4_BASE 0x480ba000

+#define OMAP2_MCSPI_MASTER 0
+#define OMAP2_MCSPI_SLAVE 1
+

If these are to be 'mode' flags for 'struct
omap2_mcspi_platform_config' then they should be part of mcspi.h, not
defined here.


Will move them to mcspi.h



 static struct omap2_mcspi_platform_config omap2_mcspi1_config = {
 .num_cs = 4,
+ .force_cs_mode = 1,
 };

 static struct resource omap2_mcspi1_resources[] = {
@@ -281,6 +285,10 @@

 static struct omap2_mcspi_platform_config omap2_mcspi2_config = {
 .num_cs = 2,
+ .mode = OMAP2_MCSPI_MASTER,
+ .dma_mode = 1,
+ .force_cs_mode = 0,
+ .fifo_depth = 0,

Setting these init values to zero is redundant.

This is to serve as an easy reference for someone trying to enable these 
features.



 };

 static struct resource omap2_mcspi2_resources[] = {
@@ -351,6 +359,14 @@

 static void omap_init_mcspi(void)
 {
+
+ if (cpu_is_omap3430()) {
+ omap_cfg_reg(AA3_3430_McSPI2_CLK);
+ omap_cfg_reg(Y2_3430_McSPI2_SIMO);
+ omap_cfg_reg(Y3_3430_McSPI2_SOMI);
+ omap_cfg_reg(Y4_3430_McSPI2_CS0);
+ }
+
 platform_device_register(&omap2_mcspi1);
 platform_device_register(&omap2_mcspi2);
 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3)
Index: linux-omap-2.6/arch/arm/mach-omap2/mux.c
===================================================================
--- linux-omap-2.6.orig/arch/arm/mach-omap2/mux.c 2009-05-14 
12:38:50.000000000
+0530
+++ linux-omap-2.6/arch/arm/mach-omap2/mux.c 2009-05-15 
16:18:41.000000000 +0530
@@ -486,6 +486,17 @@
 OMAP34XX_MUX_MODE4 | OMAP34XX_PIN_OUTPUT)
 MUX_CFG_34XX("J25_34XX_GPIO170", 0x1c6,
 OMAP34XX_MUX_MODE4 | OMAP34XX_PIN_INPUT)
+
+/* McSPI */
+MUX_CFG_34XX("AA3_3430_McSPI2_CLK", 0x1d6,
+ OMAP34XX_MUX_MODE0 | OMAP34XX_PIN_INPUT)
+MUX_CFG_34XX("Y2_3430_McSPI2_SIMO", 0x1d8,
+ OMAP34XX_MUX_MODE0 | OMAP34XX_PIN_INPUT)
+MUX_CFG_34XX("Y3_3430_McSPI2_SOMI", 0x1da,
+ OMAP34XX_MUX_MODE0 | OMAP34XX_PIN_INPUT)
+MUX_CFG_34XX("Y4_3430_McSPI2_CS0", 0x1dc,
+ OMAP34XX_MUX_MODE0 | OMAP34XX_PIN_INPUT_PULLDOWN)
+
 };

 #define OMAP34XX_PINS_SZ ARRAY_SIZE(omap34xx_pins)
Index: linux-omap-2.6/arch/arm/plat-omap/include/mach/mcspi.h
===================================================================
--- linux-omap-2.6.orig/arch/arm/plat-omap/include/mach/mcspi.h 
2009-05-14
12:38:54.000000000 +0530
+++ linux-omap-2.6/arch/arm/plat-omap/include/mach/mcspi.h 2009-05-14
19:48:35.000000000 +0530
@@ -3,6 +3,19 @@

 struct omap2_mcspi_platform_config {
 unsigned short num_cs;
+
+ /* SPI is master or slave */
+ unsigned short mode;
+
+ /* Use only DMA for data transfers */
+ unsigned short dma_mode;
+
+ /* Force chip select mode */
+ unsigned short force_cs_mode;
+
+ /* FIFO depth in bytes, max value 64 */
+ unsigned short fifo_depth;
+
 };

 struct omap2_mcspi_device_config {
Index: linux-omap-2.6/arch/arm/plat-omap/include/mach/mux.h
===================================================================
--- linux-omap-2.6.orig/arch/arm/plat-omap/include/mach/mux.h 2009-05-14
12:38:54.000000000 +0530
+++ linux-omap-2.6/arch/arm/plat-omap/include/mach/mux.h 2009-05-15
16:22:28.000000000 +0530
@@ -853,6 +853,13 @@
 AE5_34XX_GPIO143,
 H19_34XX_GPIO164_OUT,
 J25_34XX_GPIO170,
+
+ /* McSPI */
+ AA3_3430_McSPI2_CLK,
+ Y2_3430_McSPI2_SIMO,
+ Y3_3430_McSPI2_SOMI,
+ Y4_3430_McSPI2_CS0,
+
 };

 struct omap_mux_cfg {
Index: linux-omap-2.6/drivers/spi/omap2_mcspi.c
===================================================================
--- linux-omap-2.6.orig/drivers/spi/omap2_mcspi.c 2009-05-14 
12:37:40.000000000
+0530
+++ linux-omap-2.6/drivers/spi/omap2_mcspi.c 2009-05-15 
17:33:05.000000000 +0530
@@ -37,9 +37,11 @@

 #include <mach/dma.h>
 #include <mach/clock.h>
+#include <mach/mcspi.h>


 #define OMAP2_MCSPI_MAX_FREQ 48000000
+#define OMAP2_MCSPI_MAX_FIFODEPTH 64

 #define OMAP2_MCSPI_REVISION 0x00
 #define OMAP2_MCSPI_SYSCONFIG 0x10
@@ -49,6 +51,7 @@
 #define OMAP2_MCSPI_WAKEUPENABLE 0x20
 #define OMAP2_MCSPI_SYST 0x24
 #define OMAP2_MCSPI_MODULCTRL 0x28
+#define OMAP2_MCSPI_XFERLEVEL 0x7c

 /* per-channel banks, 0x14 bytes each, first is: */
 #define OMAP2_MCSPI_CHCONF0 0x2c
@@ -85,6 +88,9 @@
 #define OMAP2_MCSPI_CHCONF_IS BIT(18)
 #define OMAP2_MCSPI_CHCONF_TURBO BIT(19)
 #define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
+#define OMAP2_MCSPI_CHCONF_FFER BIT(28)
+#define OMAP2_MCSPI_CHCONF_FFET BIT(27)
+

 #define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
 #define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
@@ -93,6 +99,10 @@
 #define OMAP2_MCSPI_CHCTRL_EN BIT(0)

 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0)
+#define OMAP2_MCSPI_IRQ_EOW BIT(17)
+
+#define OMAP2_MCSPI_MODE_IS_MASTER 0
+#define OMAP2_MCSPI_MODE_IS_SLAVE 1

This is the 2nd define of the master/slave mode flags.  Pick a name
and define it once in mcspi.h.


Will move them to mcspi.h




 /* We have 2 DMA channels per CS, one for RX and one for TX */
 struct omap2_mcspi_dma {
@@ -125,6 +135,10 @@
 unsigned long phys;
 /* SPI1 has 4 channels, while SPI2 has 2 */
 struct omap2_mcspi_dma *dma_channels;
+ unsigned short mcspi_mode;
+ unsigned short dma_mode;
+ unsigned short force_cs_mode;
+ unsigned short fifo_depth;
 };

 struct omap2_mcspi_cs {
@@ -133,6 +147,37 @@
 int word_len;
 };

+#ifdef CONFIG_SPI_DEBUG
+struct reg_type {
+ char name[40];
+ int offset;
+};
+
+static struct reg_type reg_map[] = {
+ {"MCSPI_REV", 0x0},
+ {"MCSPI_SYSCONFIG", 0x10},
+ {"MCSPI_SYSSTATUS", 0x14},
+ {"MCSPI_IRQSTATUS", 0x18},
+ {"MCSPI_IRQENABLE", 0x1C},
+ {"MCSPI_WAKEUPENABLE", 0x20},
+ {"MCSPI_SYST", 0x24},
+ {"MCSPI_MODULCTRL", 0x28},
+ {"MCSPI_XFERLEVEL", 0x7c},
+ {"CH0", 0x2C},
+ {"CH1", 0x40},
+ {"CH2", 0x54},
+ {"CH3", 0x68}
+};
+
+static struct reg_type ch_reg_type[] = {
+ {"CONF", 0x00},
+ {"STAT", 0x04},
+ {"CTRL", 0x08},
+ {"TX", 0x0C},
+ {"RX", 0x10},
+};
+#endif
+
 static struct workqueue_struct *omap2_mcspi_wq;

 #define MOD_REG_BIT(val, mask, set) do { \
@@ -188,6 +233,44 @@
 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 }

+#ifdef CONFIG_SPI_DEBUG
+static int
+omap2_mcspi_dump_regs(struct spi_master *master)
+{
+ u32 spi_base;
+ u32 reg;
+ u32 bus;
+ u32 chan;
+ u32 channel;
+ struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+ spi_base = mcspi->base;
+
+ for (reg = 0; (reg < sizeof(reg_map) / sizeof(struct reg_type));

You could use ARRAY_SIZE() here.

Yes I think that will make the code look cleaner,




+      reg++) {
+ struct reg_type *reg_d = &reg_map[reg];
+ u32 base1 = spi_base + reg_d->offset;
+ if (reg_d->name[0] == 'C') {
+ for (channel = 0;
+      (channel < (sizeof(ch_reg_type) /
+ sizeof(struct reg_type)));
+      channel++) {
+ struct reg_type *reg_c = &ch_reg_type[channel];
+ u32 base2 = base1 + reg_c->offset;
+ printk(KERN_DEBUG "MCSPI_%s%s [0x%08X] = 0x%08X\n",
+        reg_d->name, reg_c->name, base2,
+        __raw_readl(base2));

Use pr_debug()

Would  dev_dbg() be more appropriate.




+ }
+ } else {
+ printk(KERN_DEBUG "%s : [0x%08X] = 0x%08X\n",
+ reg_d->name, base1, __raw_readl(base1));

ditto

+ }
+
+ }
+ return 0;
+}
+#endif
+
 static void omap2_mcspi_set_enable(const struct spi_device *spi, int 
enable)
 {
 u32 l;
@@ -205,34 +288,149 @@
 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 }

+static int omap2_mcspi_set_txfifo(const struct spi_device *spi, int 
buf_size,
+ int enable)
+{
+ u32 l, rw, s;
+ unsigned short revert = 0;
+ struct spi_master *master = spi->master;
+ struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+ l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+ s = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
+
+ if (enable == 1) {
+ if (l & OMAP2_MCSPI_CHCONF_FFER)
+ return -1;
+
+ if (s & OMAP2_MCSPI_CHCTRL_EN) {
+ omap2_mcspi_set_enable(spi, 0);
+ revert = 1;
+ }
+
+ if (buf_size < mcspi->fifo_depth)
+ mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL,
+ ((buf_size << 16) |
+ (buf_size - 1) << 0));
+ else
+ mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL,
+ ((buf_size << 16) |
+ (mcspi->fifo_depth - 1) << 0));
+ }
+
+ rw = OMAP2_MCSPI_CHCONF_FFET;
+ MOD_REG_BIT(l, rw, enable);
+ mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+
+ if (revert)
+ omap2_mcspi_set_enable(spi, 1);
+
+ return 0;
+
+}
+
+static int omap2_mcspi_set_rxfifo(const struct spi_device *spi, int 
buf_size,
+ int enable)
+{
+ u32 l, rw, s;
+ unsigned short revert = 0;
+ struct spi_master *master = spi->master;
+ struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
+
+ l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
+ s = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
+
+ if (enable == 1) {
+ if (l & OMAP2_MCSPI_CHCONF_FFET)
+ return -1;
+
+ /* Channel needs to be disabled and enabled
+ * again for FIFO setting to take affect
+ */
+ if (s & OMAP2_MCSPI_CHCTRL_EN) {
+ omap2_mcspi_set_enable(spi, 0);
+ revert = 1;
+ }
+
+ if (buf_size < mcspi->fifo_depth)
+ mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL,
+ ((buf_size << 16) |
+ (buf_size - 1) << 8));
+ else
+ mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL,
+ ((buf_size << 16) |
+ (mcspi->fifo_depth - 1) << 8));
+ }
+
+ rw = OMAP2_MCSPI_CHCONF_FFER;
+ MOD_REG_BIT(l, rw, enable);
+ mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
+
+ if (revert)
+ omap2_mcspi_set_enable(spi, 1);
+
+ return 0;
+
+}
+
 static void omap2_mcspi_set_master_mode(struct spi_master *master)
 {
 u32 l;
+ struct omap2_mcspi *mcspi = spi_master_get_devdata(master);

 /* setup when switching from (reset default) slave mode
- * to single-channel master mode
+ * to single-channel master mode based on config value
 */
 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);
+
+ if (mcspi->force_cs_mode)
+ MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
+
+ mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
+}
+
+static void omap2_mcspi_set_slave_mode(struct spi_master *master)
+{
+ u32 l;
+
+ 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, 1);
 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 }

+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_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 int count, c, bytes_per_transfer;
 unsigned long base, tx_reg, rx_reg;
- int word_len, data_type, element_count;
- u8 * rx;
- const u8 * tx;
+ int word_len, data_type, element_count, frame_count,
+ sync_type;
+ u8 *rx;
+ const u8 *tx;
+ void __iomem            *irqstat_reg;

 mcspi = spi_master_get_devdata(spi->master);
 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
+ irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;

 count = xfer->len;
 c = count;
@@ -247,19 +445,34 @@
 if (word_len <= 8) {
 data_type = OMAP_DMA_DATA_TYPE_S8;
 element_count = count;
+ bytes_per_transfer = 1;
 } else if (word_len <= 16) {
 data_type = OMAP_DMA_DATA_TYPE_S16;
 element_count = count >> 1;
+ bytes_per_transfer = 2;
 } else /* word_len <= 32 */ {
 data_type = OMAP_DMA_DATA_TYPE_S32;
 element_count = count >> 2;
+ bytes_per_transfer = 4;
+ }
+
+ if ((mcspi->fifo_depth != 0) && (count > mcspi->fifo_depth)) {
+ sync_type = OMAP_DMA_SYNC_FRAME;
+ element_count = mcspi->fifo_depth/bytes_per_transfer;
+ frame_count = count/mcspi->fifo_depth;
+ } else if ((mcspi->fifo_depth != 0) && (count <=  mcspi->fifo_depth)) {
+ sync_type = OMAP_DMA_SYNC_FRAME;
+ frame_count = 1;
+ } else {
+ sync_type = OMAP_DMA_SYNC_ELEMENT;
+ frame_count = 1;
 }

 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);
+ data_type, element_count, frame_count,
+ sync_type, mcspi_dma->dma_tx_sync_dev, 0);

 omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
 OMAP_DMA_AMODE_CONSTANT,
@@ -268,13 +481,16 @@
 omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
 OMAP_DMA_AMODE_POST_INC,
 xfer->tx_dma, 0, 0);
+
+ if (mcspi->fifo_depth != 0)
+ omap2_mcspi_set_txfifo(spi, count, 1);
 }

 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);
+ data_type, element_count, frame_count,
+ sync_type, mcspi_dma->dma_rx_sync_dev, 1);

 omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
 OMAP_DMA_AMODE_CONSTANT,
@@ -283,6 +499,14 @@
 omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
 OMAP_DMA_AMODE_POST_INC,
 xfer->rx_dma, 0, 0);
+
+ if (mcspi->fifo_depth != 0) {
+ omap2_mcspi_set_rxfifo(spi, count, 1);
+
+ /* Dummy write required for RX only mode */
+ if (tx == NULL)
+ mcspi_write_cs_reg(spi, OMAP2_MCSPI_TX0, 0);
+ }
 }

 if (tx != NULL) {
@@ -297,27 +521,35 @@

 if (tx != NULL) {
 wait_for_completion(&mcspi_dma->dma_tx_completion);
+
+ if (mcspi->fifo_depth != 0) {
+ if (mcspi_wait_for_reg_bit(irqstat_reg,
+ OMAP2_MCSPI_IRQ_EOW) < 0)
+ dev_err(&spi->dev, "TXS timed out\n");
+
+ mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
+ OMAP2_MCSPI_IRQ_EOW);
+
+ omap2_mcspi_set_txfifo(spi, count, 0);
+ }
+
 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;
+ if (mcspi->fifo_depth != 0) {
+ omap2_mcspi_set_rxfifo(spi, count, 0);

- timeout = jiffies + msecs_to_jiffies(1000);
- while (!(__raw_readl(reg) & bit)) {
- if (time_after(jiffies, timeout))
- return -1;
- cpu_relax();
+ mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
+ OMAP2_MCSPI_IRQ_EOW);
+
+ }
+
+ dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
 }
- return 0;
+ return count;
 }

 static unsigned
@@ -508,8 +740,14 @@
 /* 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;
+ if (mcspi->mcspi_mode == OMAP2_MCSPI_MODE_IS_MASTER) {
+ l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
+ l |= OMAP2_MCSPI_CHCONF_DPE0;
+ } else {
+ l |= OMAP2_MCSPI_CHCONF_IS;
+ l |= OMAP2_MCSPI_CHCONF_DPE1;
+ l &= ~OMAP2_MCSPI_CHCONF_DPE0;
+ }

 /* wordlength */
 l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
@@ -521,9 +759,11 @@
 else
 l &= ~OMAP2_MCSPI_CHCONF_EPOL;

- /* set clock divisor */
- l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
- l |= div << 2;
+ if (mcspi->mcspi_mode == OMAP2_MCSPI_MODE_IS_MASTER) {
+ /* set clock divisor */
+ l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
+ l |= div << 2;
+ }

 /* set SPI mode 0..3 */
 if (spi->mode & SPI_CPOL)
@@ -688,7 +928,7 @@
 clk_enable(mcspi->ick);
 clk_enable(mcspi->fck);

- /* We only enable one channel at a time -- the one whose message is
+ /*  only enable one channel at a time -- the one whose message is

Heh, are you against first person plural comments. ;)

Seems to have sneaked in somehow, will correct that,


 * 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
@@ -728,7 +968,10 @@
 par_override = 0;
 }

- if (!cs_active) {
+ if ((!cs_active) && (mcspi->force_cs_mode) &&
+ (mcspi->mcspi_mode ==
+ OMAP2_MCSPI_MODE_IS_MASTER)) {
+
 omap2_mcspi_force_cs(spi, 1);
 cs_active = 1;
 }
@@ -749,10 +992,14 @@
 __raw_writel(0, cs->base
 + OMAP2_MCSPI_TX0);

- if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
+ if (m->is_dma_mapped ||
+ t->len >= DMA_MIN_BYTES ||
+ mcspi->dma_mode)
+
 count = omap2_mcspi_txrx_dma(spi, t);
 else
 count = omap2_mcspi_txrx_pio(spi, t);
+
 m->actual_length += count;

 if (count != t->len) {
@@ -765,7 +1012,10 @@
 udelay(t->delay_usecs);

 /* ignore the "leave it on after last xfer" hint */
- if (t->cs_change) {
+ if ((t->cs_change) && (mcspi->force_cs_mode) &&
+ (mcspi->mcspi_mode ==
+ OMAP2_MCSPI_MODE_IS_MASTER)) {
+
 omap2_mcspi_force_cs(spi, 0);
 cs_active = 0;
 }
@@ -777,8 +1027,9 @@
 status = omap2_mcspi_setup_transfer(spi, NULL);
 }

- if (cs_active)
- omap2_mcspi_force_cs(spi, 0);
+ if ((cs_active) && (mcspi->force_cs_mode) &&
+ (mcspi->mcspi_mode == OMAP2_MCSPI_MODE_IS_MASTER))
+ omap2_mcspi_force_cs(spi, 0);

 omap2_mcspi_set_enable(spi, 0);

@@ -803,6 +1054,8 @@
 m->actual_length = 0;
 m->status = 0;

+ mcspi = spi_master_get_devdata(spi->master);
+
 /* reject invalid messages and transfers */
 if (list_empty(&m->transfers) || !m->complete)
 return -EINVAL;
@@ -831,7 +1084,14 @@
 return -EINVAL;
 }

- if (m->is_dma_mapped || len < DMA_MIN_BYTES)
+ if (mcspi->fifo_depth != 0) {
+ if ((len % mcspi->fifo_depth) != 0)
+ return -EINVAL;
+ }
+
+ /* Ignore DMA_MIN_BYTES check if dma only mode is set */
+ if (m->is_dma_mapped || ((len < DMA_MIN_BYTES) &&
+ (!mcspi->dma_mode)))
 continue;

 /* Do DMA mapping "early" for better error reporting and
@@ -862,8 +1122,6 @@
 }
 }

- 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);
@@ -894,7 +1152,10 @@
 mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
 OMAP2_MCSPI_WAKEUPENABLE_WKEN);

- omap2_mcspi_set_master_mode(master);
+ if (mcspi->mcspi_mode == OMAP2_MCSPI_MODE_IS_MASTER)
+ omap2_mcspi_set_master_mode(master);
+ else
+ omap2_mcspi_set_slave_mode(master);

 clk_disable(mcspi->fck);
 clk_disable(mcspi->ick);
@@ -950,6 +1211,8 @@
 static int __init omap2_mcspi_probe(struct platform_device *pdev)
 {
 struct spi_master *master;
+ struct omap2_mcspi_platform_config *pdata =
+ (struct omap2_mcspi_platform_config *)pdev->dev.platform_data;
 struct omap2_mcspi *mcspi;
 struct resource *r;
 int status = 0, i;
@@ -1003,6 +1266,16 @@

 mcspi = spi_master_get_devdata(master);
 mcspi->master = master;
+ mcspi->mcspi_mode = pdata->mode;
+ mcspi->dma_mode = pdata->dma_mode;
+ mcspi->force_cs_mode = pdata->force_cs_mode;
+
+ if (pdata->fifo_depth <= OMAP2_MCSPI_MAX_FIFODEPTH)
+ mcspi->fifo_depth = pdata->fifo_depth;
+ else {
+ mcspi->fifo_depth = 0;
+ dev_dbg(&pdev->dev, "Invalid fifo depth specified\n");

Would seeting to MAX_FIFODEPTH be more appropriate here, along with
a warning.


No that would not work, the idea is to use SYNC_FRAME for DMA and the user
buffer needs to be a multiple of fifo_depth for that to work. Hence setting 
a default
value of MAX_FIFODEPTH could break it.




+ }

 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 if (r == NULL) {

Kevin



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