#include <linux/dma-mapping.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
-#include <linux/errno.h>
#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/gpio.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/pxa2xx_spi.h>
+#include <mach/dma.h>
+#include <mach/regs-ssp.h>
+#include <mach/ssp.h>
+#include <mach/pxa2xx_spi.h>
MODULE_AUTHOR("Stephen Street");
-MODULE_DESCRIPTION("PXA2xx SSP SPI Contoller");
+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)
+#define RX_THRESH_DFLT 8
+#define TX_THRESH_DFLT 8
+#define TIMOUT_DFLT 1000
+
+#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)
+#define MAX_DMA_LEN 8191
+#define DMA_ALIGNMENT 8
+
+/*
+ * 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 *p) { return __raw_readl(p + (off)); } \
-static inline void write_##reg(u32 v, void *p) { __raw_writel(v, p + (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)
/* 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;
u32 *null_dma_buf;
/* SSP register addresses */
- void *ioaddr;
+ void __iomem *ioaddr;
u32 ssdr_physical;
/* SSP masks*/
size_t tx_map_len;
u8 n_bytes;
u32 dma_width;
- int cs_change;
- void (*write)(struct driver_data *drv_data);
- void (*read)(struct driver_data *drv_data);
+ 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 to;
u32 psp;
u32 timeout;
u8 n_bytes;
u8 enable_dma;
u8 bits_per_word;
u32 speed_hz;
- void (*write)(struct driver_data *drv_data);
- void (*read)(struct driver_data *drv_data);
+ int gpio_cs;
+ int gpio_cs_inverted;
+ int (*write)(struct driver_data *drv_data);
+ int (*read)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
};
-static void pump_messages(void *data);
+static void pump_messages(struct work_struct *work);
+
+static void cs_assert(struct driver_data *drv_data)
+{
+ struct chip_data *chip = drv_data->cur_chip;
+
+ if (chip->cs_control) {
+ chip->cs_control(PXA2XX_CS_ASSERT);
+ return;
+ }
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
+}
+
+static void cs_deassert(struct driver_data *drv_data)
+{
+ struct chip_data *chip = drv_data->cur_chip;
+
+ if (chip->cs_control) {
+ chip->cs_control(PXA2XX_CS_DEASSERT);
+ return;
+ }
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
+}
static int flush(struct driver_data *drv_data)
{
unsigned long limit = loops_per_jiffy << 1;
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
do {
while (read_SSSR(reg) & SSSR_RNE) {
read_SSDR(reg);
}
- } while ((read_SSSR(reg) & SSSR_BSY) && limit--);
+ } while ((read_SSSR(reg) & SSSR_BSY) && --limit);
write_SSSR(SSSR_ROR, reg);
return limit;
}
-static void restore_state(struct driver_data *drv_data)
+static int null_writer(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
-
- /* Clear status and disable clock */
- write_SSSR(drv_data->clear_sr, reg);
- write_SSCR0(drv_data->cur_chip->cr0 & ~SSCR0_SSE, reg);
+ void __iomem *reg = drv_data->ioaddr;
+ u8 n_bytes = drv_data->n_bytes;
- /* Load the registers */
- write_SSCR1(drv_data->cur_chip->cr1, reg);
- write_SSCR0(drv_data->cur_chip->cr0, reg);
- if (drv_data->ssp_type != PXA25x_SSP) {
- write_SSTO(0, reg);
- write_SSPSP(drv_data->cur_chip->psp, reg);
- }
-}
+ if (((read_SSSR(reg) & 0x00000f00) == 0x00000f00)
+ || (drv_data->tx == drv_data->tx_end))
+ return 0;
-static void null_cs_control(u32 command)
-{
-}
+ write_SSDR(0, reg);
+ drv_data->tx += n_bytes;
-static void null_writer(struct driver_data *drv_data)
-{
- void *reg = drv_data->ioaddr;
- u8 n_bytes = drv_data->n_bytes;
-
- while ((read_SSSR(reg) & SSSR_TNF)
- && (drv_data->tx < drv_data->tx_end)) {
- write_SSDR(0, reg);
- drv_data->tx += n_bytes;
- }
+ return 1;
}
-static void null_reader(struct driver_data *drv_data)
+static int null_reader(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ 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)) {
+ && (drv_data->rx < drv_data->rx_end)) {
read_SSDR(reg);
drv_data->rx += n_bytes;
}
+
+ return drv_data->rx == drv_data->rx_end;
}
-static void u8_writer(struct driver_data *drv_data)
+static int u8_writer(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
- while ((read_SSSR(reg) & SSSR_TNF)
- && (drv_data->tx < drv_data->tx_end)) {
- write_SSDR(*(u8 *)(drv_data->tx), reg);
- ++drv_data->tx;
- }
+ 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 void u8_reader(struct driver_data *drv_data)
+static int u8_reader(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
- && (drv_data->rx < drv_data->rx_end)) {
+ && (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 void u16_writer(struct driver_data *drv_data)
+static int u16_writer(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
- while ((read_SSSR(reg) & SSSR_TNF)
- && (drv_data->tx < drv_data->tx_end)) {
- write_SSDR(*(u16 *)(drv_data->tx), reg);
- drv_data->tx += 2;
- }
+ 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 void u16_reader(struct driver_data *drv_data)
+static int u16_reader(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
- && (drv_data->rx < drv_data->rx_end)) {
+ && (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 void u32_writer(struct driver_data *drv_data)
+
+static int u32_writer(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
- while ((read_SSSR(reg) & SSSR_TNF)
- && (drv_data->tx < drv_data->tx_end)) {
- write_SSDR(*(u32 *)(drv_data->tx), reg);
- drv_data->tx += 4;
- }
+ 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 void u32_reader(struct driver_data *drv_data)
+static int u32_reader(struct driver_data *drv_data)
{
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
while ((read_SSSR(reg) & SSSR_RNE)
- && (drv_data->rx < drv_data->rx_end)) {
+ && (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)
} 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 */
+ /* Stream map the tx buffer. Always do DMA_TO_DEVICE first
+ * so we flush the cache *before* invalidating it, in case
+ * the tx and rx buffers overlap.
+ */
drv_data->tx_dma = dma_map_single(dev, drv_data->tx,
- drv_data->tx_map_len,
- DMA_TO_DEVICE);
+ drv_data->tx_map_len, DMA_TO_DEVICE);
+ if (dma_mapping_error(dev, drv_data->tx_dma))
+ return 0;
- if (dma_mapping_error(drv_data->tx_dma)) {
- dma_unmap_single(dev, drv_data->rx_dma,
+ /* 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(dev, drv_data->rx_dma)) {
+ dma_unmap_single(dev, drv_data->tx_dma,
+ drv_data->tx_map_len, DMA_TO_DEVICE);
return 0;
}
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);
struct spi_transfer,
transfer_list);
+ /* Delay if requested before any change in chip select */
+ if (last_transfer->delay_usecs)
+ udelay(last_transfer->delay_usecs);
+
+ /* Drop chip select UNLESS cs_change is true or we are returning
+ * a message with an error, or next message is for another chip
+ */
if (!last_transfer->cs_change)
- drv_data->cs_control(PXA2XX_CS_DEASSERT);
+ cs_deassert(drv_data);
+ else {
+ struct spi_message *next_msg;
+
+ /* Holding of cs was hinted, but we need to make sure
+ * the next message is for the same chip. Don't waste
+ * time with the following tests unless this was hinted.
+ *
+ * We cannot postpone this until pump_messages, because
+ * after calling msg->complete (below) the driver that
+ * sent the current message could be unloaded, which
+ * could invalidate the cs_control() callback...
+ */
+
+ /* get a pointer to the next message, if any */
+ spin_lock_irqsave(&drv_data->lock, flags);
+ if (list_empty(&drv_data->queue))
+ next_msg = NULL;
+ else
+ next_msg = list_entry(drv_data->queue.next,
+ struct spi_message, queue);
+ spin_unlock_irqrestore(&drv_data->lock, flags);
+
+ /* see if the next and current messages point
+ * to the same chip
+ */
+ if (next_msg && next_msg->spi != msg->spi)
+ next_msg = NULL;
+ if (!next_msg || msg->state == ERROR_STATE)
+ cs_deassert(drv_data);
+ }
msg->state = NULL;
if (msg->complete)
msg->complete(msg->context);
+
+ drv_data->cur_chip = NULL;
}
-static int wait_ssp_rx_stall(void *ioaddr)
+static int wait_ssp_rx_stall(void const __iomem *ioaddr)
{
unsigned long limit = loops_per_jiffy << 1;
- while ((read_SSSR(ioaddr) & SSSR_BSY) && limit--)
+ while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit)
cpu_relax();
return limit;
{
unsigned long limit = loops_per_jiffy << 1;
- while (!(DCSR(channel) & DCSR_STOPSTATE) && limit--)
+ while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit)
cpu_relax();
return limit;
}
-static void dma_handler(int channel, void *data)
+static void dma_error_stop(struct driver_data *drv_data, const char *msg)
{
- struct driver_data *drv_data = data;
+ 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;
- void *reg = drv_data->ioaddr;
- u32 irq_status = DCSR(channel) & DMA_INT_MASK;
- u32 trailing_sssr = 0;
- if (irq_status & DCSR_BUSERR) {
+ /* 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;
- /* Disable interrupts, clear status and reset DMA */
- write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
- write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
- if (drv_data->ssp_type != PXA25x_SSP)
- write_SSTO(0, reg);
- write_SSSR(drv_data->clear_sr, reg);
- DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
- DCSR(drv_data->tx_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 (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_handler: flush fail\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);
+ 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);
+
+ /* Transfer delays and chip select release are
+ * handled in pump_transfers or giveback
+ */
+
+ /* 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)
- dev_err(&drv_data->pdev->dev,
- "dma_handler: bad bus address on "
- "tx channel %d, source %x target = %x\n",
- channel, DSADR(channel), DTADR(channel));
+ dma_error_stop(drv_data,
+ "dma_handler: "
+ "bad bus address on tx channel");
else
- dev_err(&drv_data->pdev->dev,
- "dma_handler: bad bus address on "
- "rx channel %d, source %x target = %x\n",
- channel, DSADR(channel), DTADR(channel));
-
- msg->state = ERROR_STATE;
- tasklet_schedule(&drv_data->pump_transfers);
+ 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 ((drv_data->ssp_type == PXA25x_SSP)
- && (channel == drv_data->tx_channel)
- && (irq_status & DCSR_ENDINTR)) {
+ 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");
- /* 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");
-
- unmap_dma_buffers(drv_data);
-
- /* Read trailing bytes */
- /* Calculate number of trailing bytes, read them */
- trailing_sssr = read_SSSR(reg);
- if ((trailing_sssr & 0xf008) != 0xf000) {
- drv_data->rx = drv_data->rx_end -
- (((trailing_sssr >> 12) & 0x0f) + 1);
- drv_data->read(drv_data);
- }
- msg->actual_length += drv_data->len;
-
- /* 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);
+ /* finish this transfer, start the next */
+ dma_transfer_complete(drv_data);
}
}
static irqreturn_t dma_transfer(struct driver_data *drv_data)
{
u32 irq_status;
- u32 trailing_sssr = 0;
- struct spi_message *msg = drv_data->cur_msg;
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
irq_status = read_SSSR(reg) & drv_data->mask_sr;
if (irq_status & SSSR_ROR) {
- /* Clear and disable interrupts on SSP and DMA channels*/
- write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
- write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
- if (drv_data->ssp_type != PXA25x_SSP)
- write_SSTO(0, reg);
- write_SSSR(drv_data->clear_sr, reg);
- DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
- DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
- unmap_dma_buffers(drv_data);
-
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_transfer: flush fail\n");
-
- dev_warn(&drv_data->pdev->dev, "dma_transfer: fifo overun\n");
-
- drv_data->cur_msg->state = ERROR_STATE;
- tasklet_schedule(&drv_data->pump_transfers);
-
+ 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) {
+ 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 interrupts on SSP and DMA channels*/
- write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
+ /* Clear and disable timeout interrupt, do the rest in
+ * dma_transfer_complete */
if (drv_data->ssp_type != PXA25x_SSP)
write_SSTO(0, 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_transfer: 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);
-
- /* Calculate number of trailing bytes, read them */
- trailing_sssr = read_SSSR(reg);
- if ((trailing_sssr & 0xf008) != 0xf000) {
- drv_data->rx = drv_data->rx_end -
- (((trailing_sssr >> 12) & 0x0f) + 1);
- drv_data->read(drv_data);
- }
- msg->actual_length += drv_data->len;
-
- /* 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);
+ /* finish this transfer, start the next */
+ dma_transfer_complete(drv_data);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
-static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
+static void int_error_stop(struct driver_data *drv_data, const char* msg)
{
- struct spi_message *msg = drv_data->cur_msg;
- void *reg = drv_data->ioaddr;
- unsigned long limit = loops_per_jiffy << 1;
- u32 irq_status;
- u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
- drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
-
- while ((irq_status = read_SSSR(reg) & irq_mask)) {
-
- if (irq_status & SSSR_ROR) {
+ void __iomem *reg = drv_data->ioaddr;
- /* Clear and disable interrupts */
- 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);
+ /* 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);
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "interrupt_transfer: flush fail\n");
+ dev_err(&drv_data->pdev->dev, "%s\n", msg);
- /* Stop the SSP */
+ drv_data->cur_msg->state = ERROR_STATE;
+ tasklet_schedule(&drv_data->pump_transfers);
+}
- dev_warn(&drv_data->pdev->dev,
- "interrupt_transfer: fifo overun\n");
+static void int_transfer_complete(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
- msg->state = ERROR_STATE;
- tasklet_schedule(&drv_data->pump_transfers);
+ /* 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);
- return IRQ_HANDLED;
- }
+ /* 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);
- /* Look for false positive timeout */
- if ((irq_status & SSSR_TINT)
- && (drv_data->rx < drv_data->rx_end))
- write_SSSR(SSSR_TINT, reg);
+ /* Transfer delays and chip select release are
+ * handled in pump_transfers or giveback
+ */
- /* Pump data */
- drv_data->read(drv_data);
- drv_data->write(drv_data);
+ /* Move to next transfer */
+ drv_data->cur_msg->state = next_transfer(drv_data);
- if (drv_data->tx == drv_data->tx_end) {
- /* Disable tx interrupt */
- write_SSCR1(read_SSCR1(reg) & ~SSCR1_TIE, reg);
- irq_mask = drv_data->mask_sr & ~SSSR_TFS;
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
+}
- /* PXA25x_SSP has no timeout, read trailing bytes */
- if (drv_data->ssp_type == PXA25x_SSP) {
- while ((read_SSSR(reg) & SSSR_BSY) && limit--)
- drv_data->read(drv_data);
+static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
+{
+ void __iomem *reg = drv_data->ioaddr;
- if (limit == 0)
- dev_err(&drv_data->pdev->dev,
- "interrupt_transfer: "
- "trailing byte read failed\n");
- }
- }
+ u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ?
+ drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS;
- if ((irq_status & SSSR_TINT)
- || (drv_data->rx == drv_data->rx_end)) {
+ u32 irq_status = read_SSSR(reg) & irq_mask;
- /* Clear timeout */
- 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);
+ if (irq_status & SSSR_ROR) {
+ int_error_stop(drv_data, "interrupt_transfer: fifo overrun");
+ return IRQ_HANDLED;
+ }
- /* Update total byte transfered */
- msg->actual_length += drv_data->len;
+ if (irq_status & SSSR_TINT) {
+ write_SSSR(SSSR_TINT, reg);
+ if (drv_data->read(drv_data)) {
+ int_transfer_complete(drv_data);
+ return IRQ_HANDLED;
+ }
+ }
- /* Release chip select if requested, transfer delays are
- * handled in pump_transfers */
- if (drv_data->cs_change)
- drv_data->cs_control(PXA2XX_CS_DEASSERT);
+ /* 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));
- /* Move to next transfer */
- msg->state = next_transfer(drv_data);
+ if (drv_data->read(drv_data)) {
+ int_transfer_complete(drv_data);
+ return IRQ_HANDLED;
+ }
- /* Schedule transfer tasklet */
- tasklet_schedule(&drv_data->pump_transfers);
+ 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);
}
}
static irqreturn_t ssp_int(int irq, void *dev_id)
{
struct driver_data *drv_data = dev_id;
- void *reg = drv_data->ioaddr;
+ void __iomem *reg = drv_data->ioaddr;
if (!drv_data->cur_msg) {
write_SSSR(drv_data->clear_sr, reg);
dev_err(&drv_data->pdev->dev, "bad message state "
- "in interrupt handler");
+ "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_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
struct chip_data *chip = NULL;
- void *reg = drv_data->ioaddr;
+ 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;
return;
}
- /* Delay if requested at end of transfer*/
+ /* Delay if requested at end of transfer before CS change */
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);
+
+ /* Drop chip select only if cs_change is requested */
+ if (previous->cs_change)
+ cs_deassert(drv_data);
+ }
+
+ /* Check for transfers that need multiple DMA segments */
+ if (transfer->len > MAX_DMA_LEN && chip->enable_dma) {
+
+ /* reject already-mapped transfers; PIO won't always work */
+ if (message->is_dma_mapped
+ || transfer->rx_dma || transfer->tx_dma) {
+ dev_err(&drv_data->pdev->dev,
+ "pump_transfers: mapped transfer length "
+ "of %u is greater than %d\n",
+ transfer->len, MAX_DMA_LEN);
+ message->status = -EINVAL;
+ giveback(drv_data);
+ return;
+ }
+
+ /* warn ... we force this to PIO mode */
+ if (printk_ratelimit())
+ dev_warn(&message->spi->dev, "pump_transfers: "
+ "DMA disabled for transfer length %ld "
+ "greater than %d\n",
+ (long)drv_data->len, MAX_DMA_LEN);
}
/* Setup the transfer state based on the type of transfer */
}
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;
+ 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) {
- /* Disable clock */
- write_SSCR0(chip->cr0 & ~SSCR0_SSE, reg);
- cr0 = chip->cr0;
bits = chip->bits_per_word;
speed = chip->speed_hz;
if (transfer->bits_per_word)
bits = transfer->bits_per_word;
- if (reg == SSP1_VIRT)
- clk_div = SSP1_SerClkDiv(speed);
- else if (reg == SSP2_VIRT)
- clk_div = SSP2_SerClkDiv(speed);
- else if (reg == SSP3_VIRT)
- clk_div = SSP3_SerClkDiv(speed);
+ clk_div = ssp_get_clk_div(ssp, speed);
if (bits <= 8) {
drv_data->n_bytes = 1;
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_transfers: "
+ "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);
-
- /* Start it back up */
- write_SSCR0(cr0, reg);
}
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))) {
+ /* Try to map dma buffer and do a dma transfer if successful, but
+ * only if the length is non-zero and less than MAX_DMA_LEN.
+ *
+ * Zero-length non-descriptor DMA is illegal on PXA2xx; force use
+ * of PIO instead. Care is needed above because the transfer may
+ * have have been passed with buffers that are already dma mapped.
+ * A zero-length transfer in PIO mode will not try to write/read
+ * to/from the buffers
+ *
+ * REVISIT large transfers are exactly where we most want to be
+ * using DMA. If this happens much, split those transfers into
+ * multiple DMA segments rather than forcing PIO.
+ */
+ drv_data->dma_mapped = 0;
+ if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN)
+ drv_data->dma_mapped = map_dma_buffers(drv_data);
+ if (drv_data->dma_mapped) {
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = dma_transfer;
/* No target address increment */
DCMD(drv_data->rx_channel) = DCMD_FLOWSRC
| drv_data->dma_width
- | chip->dma_burst_size
+ | dma_burst
| drv_data->len;
else
DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR
| DCMD_FLOWSRC
| drv_data->dma_width
- | chip->dma_burst_size
+ | dma_burst
| drv_data->len;
/* Setup tx DMA Channel */
/* No source address increment */
DCMD(drv_data->tx_channel) = DCMD_FLOWTRG
| drv_data->dma_width
- | chip->dma_burst_size
+ | dma_burst
| drv_data->len;
else
DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR
| DCMD_FLOWTRG
| drv_data->dma_width
- | chip->dma_burst_size
+ | 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;
- /* Fix me, need to handle cs polarity */
- drv_data->cs_control(PXA2XX_CS_ASSERT);
-
- /* Go baby, go */
+ /* 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;
- if (drv_data->ssp_type != PXA25x_SSP)
- write_SSTO(chip->timeout, reg);
- write_SSCR1(chip->cr1
- | chip->dma_threshold
- | drv_data->dma_cr1,
- reg);
} else {
/* Ensure we have the correct interrupt handler */
drv_data->transfer_handler = interrupt_transfer;
- /* Fix me, need to handle cs polarity */
- drv_data->cs_control(PXA2XX_CS_ASSERT);
-
- /* Go baby, go */
+ /* 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);
- write_SSCR1(chip->cr1
- | chip->threshold
- | drv_data->int_cr1,
- reg);
}
+
+ cs_assert(drv_data);
+
+ /* 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(void *data)
+static void pump_messages(struct work_struct *work)
{
- struct driver_data *drv_data = data;
+ struct driver_data *drv_data =
+ container_of(work, struct driver_data, pump_messages);
unsigned long flags;
/* Lock queue and check for queue work */
struct spi_transfer,
transfer_list);
- /* Setup the SSP using the per chip configuration */
+ /* 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);
- restore_state(drv_data);
/* Mark as busy and launch transfers */
tasklet_schedule(&drv_data->pump_transfers);
return 0;
}
+static int setup_cs(struct spi_device *spi, struct chip_data *chip,
+ struct pxa2xx_spi_chip *chip_info)
+{
+ int err = 0;
+
+ if (chip == NULL || chip_info == NULL)
+ return 0;
+
+ /* NOTE: setup() can be called multiple times, possibly with
+ * different chip_info, release previously requested GPIO
+ */
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_free(chip->gpio_cs);
+
+ /* If (*cs_control) is provided, ignore GPIO chip select */
+ if (chip_info->cs_control) {
+ chip->cs_control = chip_info->cs_control;
+ return 0;
+ }
+
+ if (gpio_is_valid(chip_info->gpio_cs)) {
+ err = gpio_request(chip_info->gpio_cs, "SPI_CS");
+ if (err) {
+ dev_err(&spi->dev, "failed to request chip select "
+ "GPIO%d\n", chip_info->gpio_cs);
+ return err;
+ }
+
+ chip->gpio_cs = chip_info->gpio_cs;
+ chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
+
+ err = gpio_direction_output(chip->gpio_cs,
+ !chip->gpio_cs_inverted);
+ }
+
+ return err;
+}
+
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;
+ uint tx_thres = TX_THRESH_DFLT;
+ uint rx_thres = RX_THRESH_DFLT;
if (drv_data->ssp_type != PXA25x_SSP
- && (spi->bits_per_word < 4 || spi->bits_per_word > 32))
+ && (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 (spi->bits_per_word < 4 || spi->bits_per_word > 16)
+ }
+ 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;
+ }
- /* Only alloc (or use chip_info) on first setup */
+ /* Only alloc on first setup */
chip = spi_get_ctldata(spi);
- if (chip == NULL) {
+ if (!chip) {
chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
- if (!chip)
+ if (!chip) {
+ dev_err(&spi->dev,
+ "failed setup: can't allocate chip data\n");
return -ENOMEM;
+ }
- chip->cs_control = null_cs_control;
+ chip->gpio_cs = -1;
chip->enable_dma = 0;
- chip->timeout = SSP_TIMEOUT(1000);
- chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1);
+ chip->timeout = TIMOUT_DFLT;
chip->dma_burst_size = drv_data->master_info->enable_dma ?
DCMD_BURST8 : 0;
-
- chip_info = spi->controller_data;
}
+ /* 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 = SSP_TIMEOUT(chip_info->timeout_microsecs);
-
- chip->threshold = SSCR1_RxTresh(chip_info->rx_threshold)
- | SSCR1_TxTresh(chip_info->tx_threshold);
-
- chip->enable_dma = chip_info->dma_burst_size != 0
- && drv_data->master_info->enable_dma;
+ if (chip_info->timeout)
+ chip->timeout = chip_info->timeout;
+ if (chip_info->tx_threshold)
+ tx_thres = chip_info->tx_threshold;
+ if (chip_info->rx_threshold)
+ rx_thres = chip_info->rx_threshold;
+ chip->enable_dma = drv_data->master_info->enable_dma;
chip->dma_threshold = 0;
-
- if (chip->enable_dma) {
- if (chip_info->dma_burst_size <= 8) {
- chip->dma_threshold = SSCR1_RxTresh(8)
- | SSCR1_TxTresh(8);
- chip->dma_burst_size = DCMD_BURST8;
- } else if (chip_info->dma_burst_size <= 16) {
- chip->dma_threshold = SSCR1_RxTresh(16)
- | SSCR1_TxTresh(16);
- chip->dma_burst_size = DCMD_BURST16;
- } else {
- chip->dma_threshold = SSCR1_RxTresh(32)
- | SSCR1_TxTresh(32);
- chip->dma_burst_size = DCMD_BURST32;
- }
- }
-
-
if (chip_info->enable_loopback)
chip->cr1 = SSCR1_LBM;
}
- if (drv_data->ioaddr == SSP1_VIRT)
- clk_div = SSP1_SerClkDiv(spi->max_speed_hz);
- else if (drv_data->ioaddr == SSP2_VIRT)
- clk_div = SSP2_SerClkDiv(spi->max_speed_hz);
- else if (drv_data->ioaddr == SSP3_VIRT)
- clk_div = SSP3_SerClkDiv(spi->max_speed_hz);
- else
- return -ENODEV;
+ chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
+ (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
+
+ /* 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
spi->bits_per_word - 16 : spi->bits_per_word)
| SSCR0_SSE
| (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
- chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) << 4)
- | (((spi->mode & SPI_CPOL) != 0) << 3);
+ 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, %d Hz, mode %d\n",
- spi->bits_per_word,
- (CLOCK_SPEED_HZ)
+ dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
+ clk_get_rate(ssp->clk)
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
- spi->mode & 0x3);
+ chip->enable_dma ? "DMA" : "PIO");
else
- dev_dbg(&spi->dev, "%d bits/word, %d Hz, mode %d\n",
- spi->bits_per_word,
- (CLOCK_SPEED_HZ/2)
+ dev_dbg(&spi->dev, "%ld Hz actual, %s\n",
+ clk_get_rate(ssp->clk) / 2
/ (1 + ((chip->cr0 & SSCR0_SCR) >> 8)),
- spi->mode & 0x3);
+ chip->enable_dma ? "DMA" : "PIO");
if (spi->bits_per_word <= 8) {
chip->n_bytes = 1;
chip->write = u32_writer;
} else {
dev_err(&spi->dev, "invalid wordsize\n");
- kfree(chip);
return -ENODEV;
}
chip->bits_per_word = spi->bits_per_word;
spi_set_ctldata(spi, chip);
- return 0;
+ return setup_cs(spi, chip, chip_info);
}
-static void cleanup(const struct spi_device *spi)
+static void cleanup(struct spi_device *spi)
{
- struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
+ struct chip_data *chip = spi_get_ctldata(spi);
+
+ if (!chip)
+ return;
+
+ if (gpio_is_valid(chip->gpio_cs))
+ gpio_free(chip->gpio_cs);
kfree(chip);
}
-static int init_queue(struct driver_data *drv_data)
+static int __init init_queue(struct driver_data *drv_data)
{
INIT_LIST_HEAD(&drv_data->queue);
spin_lock_init(&drv_data->lock);
tasklet_init(&drv_data->pump_transfers,
pump_transfers, (unsigned long)drv_data);
- INIT_WORK(&drv_data->pump_messages, pump_messages, drv_data);
+ INIT_WORK(&drv_data->pump_messages, pump_messages);
drv_data->workqueue = create_singlethread_workqueue(
- drv_data->master->cdev.dev->bus_id);
+ dev_name(drv_data->master->dev.parent));
if (drv_data->workqueue == NULL)
return -EBUSY;
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;
return 0;
}
-static int pxa2xx_spi_probe(struct platform_device *pdev)
+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 = 0;
- struct resource *memory_resource;
- int irq;
- int status = 0;
+ struct driver_data *drv_data;
+ struct ssp_device *ssp;
+ int status;
platform_info = dev->platform_data;
- if (platform_info->ssp_type == SSP_UNDEFINED) {
- dev_err(&pdev->dev, "undefined SSP\n");
+ 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");
+ dev_err(&pdev->dev, "cannot 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;
+
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->bus_num = pdev->id;
master->num_chipselect = platform_info->num_chipselect;
+ master->dma_alignment = DMA_ALIGNMENT;
master->cleanup = cleanup;
master->setup = setup;
master->transfer = transfer;
- drv_data->ssp_type = platform_info->ssp_type;
+ drv_data->ssp_type = ssp->type;
drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data +
sizeof(struct driver_data)), 8);
- /* Setup register addresses */
- memory_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!memory_resource) {
- dev_err(&pdev->dev, "memory resources not defined\n");
- status = -ENODEV;
- goto out_error_master_alloc;
- }
-
- drv_data->ioaddr = (void *)io_p2v((unsigned long)(memory_resource->start));
- drv_data->ssdr_physical = memory_resource->start + 0x00000010;
- if (platform_info->ssp_type == PXA25x_SSP) {
+ 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_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR;
}
- /* Attach to IRQ */
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "irq resource not defined\n");
- status = -ENODEV;
- goto out_error_master_alloc;
- }
-
- status = request_irq(irq, ssp_int, 0, dev->bus_id, drv_data);
+ status = request_irq(ssp->irq, ssp_int, 0, dev_name(dev), drv_data);
if (status < 0) {
- dev_err(&pdev->dev, "can not get IRQ\n");
+ dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq);
goto out_error_master_alloc;
}
goto out_error_dma_alloc;
}
- if (drv_data->ioaddr == SSP1_VIRT) {
- DRCMRRXSSDR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSSDR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else if (drv_data->ioaddr == SSP2_VIRT) {
- DRCMRRXSS2DR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSS2DR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else if (drv_data->ioaddr == SSP3_VIRT) {
- DRCMRRXSS3DR = DRCMR_MAPVLD
- | drv_data->rx_channel;
- DRCMRTXSS3DR = DRCMR_MAPVLD
- | drv_data->tx_channel;
- } else {
- dev_err(dev, "bad SSP type\n");
- 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 */
- pxa_set_cken(platform_info->clock_enable, 1);
+ 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_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
+ SSCR1_TxTresh(TX_THRESH_DFLT),
+ drv_data->ioaddr);
write_SSCR0(SSCR0_SerClkDiv(2)
| SSCR0_Motorola
| SSCR0_DataSize(8),
destroy_queue(drv_data);
out_error_clock_enabled:
- pxa_set_cken(platform_info->clock_enable, 0);
+ clk_disable(ssp->clk);
out_error_dma_alloc:
if (drv_data->tx_channel != -1)
pxa_free_dma(drv_data->rx_channel);
out_error_irq_alloc:
- free_irq(irq, drv_data);
+ 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);
- int irq;
+ struct ssp_device *ssp;
int status = 0;
if (!drv_data)
return 0;
+ ssp = drv_data->ssp;
/* Remove the queue */
status = destroy_queue(drv_data);
if (status != 0)
- return status;
+ /* 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);
- pxa_set_cken(drv_data->master_info->clock_enable, 0);
+ clk_disable(ssp->clk);
/* Release DMA */
if (drv_data->master_info->enable_dma) {
- if (drv_data->ioaddr == SSP1_VIRT) {
- DRCMRRXSSDR = 0;
- DRCMRTXSSDR = 0;
- } else if (drv_data->ioaddr == SSP2_VIRT) {
- DRCMRRXSS2DR = 0;
- DRCMRTXSS2DR = 0;
- } else if (drv_data->ioaddr == SSP3_VIRT) {
- DRCMRRXSS3DR = 0;
- DRCMRTXSS3DR = 0;
- }
+ 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 */
- irq = platform_get_irq(pdev, 0);
- if (irq >= 0)
- free_irq(irq, drv_data);
+ free_irq(ssp->irq, drv_data);
+
+ /* Release SSP */
+ ssp_free(ssp);
/* Disconnect from the SPI framework */
spi_unregister_master(drv_data->master);
}
#ifdef CONFIG_PM
-static int suspend_devices(struct device *dev, void *pm_message)
-{
- pm_message_t *state = pm_message;
-
- if (dev->power.power_state.event != state->event) {
- dev_warn(dev, "pm state does not match request\n");
- return -1;
- }
-
- return 0;
-}
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;
- /* Check all childern for current power state */
- if (device_for_each_child(&pdev->dev, &state, suspend_devices) != 0) {
- dev_warn(&pdev->dev, "suspend aborted\n");
- return -1;
- }
-
status = stop_queue(drv_data);
if (status != 0)
return status;
write_SSCR0(0, drv_data->ioaddr);
- pxa_set_cken(drv_data->master_info->clock_enable, 0);
+ 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;
+ if (drv_data->rx_channel != -1)
+ DRCMR(drv_data->ssp->drcmr_rx) =
+ DRCMR_MAPVLD | drv_data->rx_channel;
+ if (drv_data->tx_channel != -1)
+ DRCMR(drv_data->ssp->drcmr_tx) =
+ DRCMR_MAPVLD | drv_data->tx_channel;
+
/* Enable the SSP clock */
- pxa_set_cken(drv_data->master_info->clock_enable, 1);
+ clk_enable(ssp->clk);
/* Start the queue running */
status = start_queue(drv_data);
static struct platform_driver driver = {
.driver = {
.name = "pxa2xx-spi",
- .bus = &platform_bus_type,
.owner = THIS_MODULE,
},
- .probe = pxa2xx_spi_probe,
- .remove = __devexit_p(pxa2xx_spi_remove),
+ .remove = pxa2xx_spi_remove,
.shutdown = pxa2xx_spi_shutdown,
.suspend = pxa2xx_spi_suspend,
.resume = pxa2xx_spi_resume,
static int __init pxa2xx_spi_init(void)
{
- platform_driver_register(&driver);
-
- return 0;
+ return platform_driver_probe(&driver, pxa2xx_spi_probe);
}
module_init(pxa2xx_spi_init);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff