[PATCH] pxa2xx-spi update

Fix some outstanding issues with the pxa2xx_spi driver when running on a
PXA270:

- Wrong timeout calculation in the setup function due to different
  peripheral clock rates in the PXAxxx family.

- Bad handling of SSSR_TFS interrupts in interrupt_transfer function.

- Added locking to interface between the pump_messages workqueue and the
  pump_transfers tasklet.

Much thanks to Juergen Beisert for the extensive testing on the PXA270.

Signed-off-by: Stephen Street <stephen@streetfiresound.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 59 insertions, 37 deletions

diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index 596bf820b70c..29aec77f98be 100644
--- a/drivers/spi/pxa2xx_spi.c
+++ b/drivers/spi/pxa2xx_spi.c
@@ -363,25 +363,30 @@ static void unmap_dma_buffers(struct driver_data *drv_data)
 }
 
 /* caller already set message->status; dma and pio irqs are blocked */
-static void giveback(struct spi_message *message, struct driver_data *drv_data)
+static void giveback(struct driver_data *drv_data)
 {
         struct spi_transfer* last_transfer;
+        unsigned long flags;
+        struct spi_message *msg;
 
-        last_transfer = list_entry(message->transfers.prev,
+        spin_lock_irqsave(&drv_data->lock, flags);
+        msg = drv_data->cur_msg;
+        drv_data->cur_msg = NULL;
+        drv_data->cur_transfer = NULL;
+        drv_data->cur_chip = NULL;
+        queue_work(drv_data->workqueue, &drv_data->pump_messages);
+        spin_unlock_irqrestore(&drv_data->lock, flags);
+
+        last_transfer = list_entry(msg->transfers.prev,
                                         struct spi_transfer,
                                         transfer_list);
 
         if (!last_transfer->cs_change)
                 drv_data->cs_control(PXA2XX_CS_DEASSERT);
 
-        message->state = NULL;
-        if (message->complete)
-                message->complete(message->context);
-
-        drv_data->cur_msg = NULL;
-        drv_data->cur_transfer = NULL;
-        drv_data->cur_chip = NULL;
-        queue_work(drv_data->workqueue, &drv_data->pump_messages);
+        msg->state = NULL;
+        if (msg->complete)
+                msg->complete(msg->context);
 }
 
 static int wait_ssp_rx_stall(void *ioaddr)
@@ -415,10 +420,11 @@ static void dma_handler(int channel, void *data, struct pt_regs *regs)
         if (irq_status & DCSR_BUSERR) {
 
                 /* 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);
-                write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
                 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
                 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
 
@@ -454,8 +460,8 @@ static void dma_handler(int channel, void *data, struct pt_regs *regs)
                                 "dma_handler: ssp rx stall failed\n");
 
                 /* Clear and disable interrupts on SSP and DMA channels*/
-                write_SSSR(drv_data->clear_sr, reg);
                 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)
@@ -497,10 +503,11 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
         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);
-                write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
                 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
                 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
                 unmap_dma_buffers(drv_data);
@@ -526,10 +533,10 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
         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);
                 if (drv_data->ssp_type != PXA25x_SSP)
                         write_SSTO(0, reg);
                 write_SSSR(drv_data->clear_sr, reg);
-                write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg);
                 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
                 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
 
@@ -572,26 +579,30 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
 
 static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 {
-        u32 irq_status;
         struct spi_message *msg = drv_data->cur_msg;
         void *reg = drv_data->ioaddr;
-        irqreturn_t handled = IRQ_NONE;
         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) & drv_data->mask_sr))) {
+        while ((irq_status = read_SSSR(reg) & irq_mask)) {
 
                 if (irq_status & SSSR_ROR) {
 
                         /* 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);
-                        write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
 
                         if (flush(drv_data) == 0)
                                 dev_err(&drv_data->pdev->dev,
                                         "interrupt_transfer: flush fail\n");
 
+                        /* Stop the SSP */
+
                         dev_warn(&drv_data->pdev->dev,
                                         "interrupt_transfer: fifo overun\n");
 
@@ -613,6 +624,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *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;
 
                         /* PXA25x_SSP has no timeout, read trailing bytes */
                         if (drv_data->ssp_type == PXA25x_SSP) {
@@ -630,10 +642,10 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
                                 || (drv_data->rx == drv_data->rx_end)) {
 
                         /* 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);
-                        write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
 
                         /* Update total byte transfered */
                         msg->actual_length += drv_data->len;
@@ -648,24 +660,29 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
 
                         /* Schedule transfer tasklet */
                         tasklet_schedule(&drv_data->pump_transfers);
-
-                        return IRQ_HANDLED;
                 }
-
-                /* We did something */
-                handled = IRQ_HANDLED;
         }
 
-        return handled;
+        /* We did something */
+        return IRQ_HANDLED;
 }
 
 static irqreturn_t ssp_int(int irq, void *dev_id, struct pt_regs *regs)
 {
         struct driver_data *drv_data = (struct driver_data *)dev_id;
+        void *reg = drv_data->ioaddr;
 
         if (!drv_data->cur_msg) {
+
+                write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg);
+                write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg);
+                if (drv_data->ssp_type != PXA25x_SSP)
+                        write_SSTO(0, reg);
+                write_SSSR(drv_data->clear_sr, reg);
+
                 dev_err(&drv_data->pdev->dev, "bad message state "
-                                "in interrupt handler\n");
+                                "in interrupt handler");
+
                 /* Never fail */
                 return IRQ_HANDLED;
         }
@@ -694,14 +711,14 @@ static void pump_transfers(unsigned long data)
         /* Handle for abort */
         if (message->state == ERROR_STATE) {
                 message->status = -EIO;
-                giveback(message, drv_data);
+                giveback(drv_data);
                 return;
         }
 
         /* Handle end of message */
         if (message->state == DONE_STATE) {
                 message->status = 0;
-                giveback(message, drv_data);
+                giveback(drv_data);
                 return;
         }
 
@@ -718,7 +735,7 @@ static void pump_transfers(unsigned long data)
         if (flush(drv_data) == 0) {
                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
                 message->status = -EIO;
-                giveback(message, drv_data);
+                giveback(drv_data);
                 return;
         }
         drv_data->n_bytes = chip->n_bytes;
@@ -782,7 +799,7 @@ static void pump_transfers(unsigned long data)
 
                 cr0 = clk_div
                         | SSCR0_Motorola
-                        | SSCR0_DataSize(bits & 0x0f)
+                        | SSCR0_DataSize(bits > 16 ? bits - 16 : bits)
                         | SSCR0_SSE
                         | (bits > 16 ? SSCR0_EDSS : 0);
 
@@ -890,8 +907,6 @@ static void pump_messages(void *data)
         drv_data->cur_msg = list_entry(drv_data->queue.next,
                                         struct spi_message, queue);
         list_del_init(&drv_data->cur_msg->queue);
-        drv_data->busy = 1;
-        spin_unlock_irqrestore(&drv_data->lock, flags);
 
         /* Initial message state*/
         drv_data->cur_msg->state = START_STATE;
@@ -905,6 +920,9 @@ static void pump_messages(void *data)
 
         /* Mark as busy and launch transfers */
         tasklet_schedule(&drv_data->pump_transfers);
+
+        drv_data->busy = 1;
+        spin_unlock_irqrestore(&drv_data->lock, flags);
 }
 
 static int transfer(struct spi_device *spi, struct spi_message *msg)
@@ -958,7 +976,7 @@ static int setup(struct spi_device *spi)
 
                 chip->cs_control = null_cs_control;
                 chip->enable_dma = 0;
-                chip->timeout = 5;
+                chip->timeout = SSP_TIMEOUT(1000);
                 chip->threshold = SSCR1_RxTresh(1) | SSCR1_TxTresh(1);
                 chip->dma_burst_size = drv_data->master_info->enable_dma ?
                                         DCMD_BURST8 : 0;
@@ -971,7 +989,7 @@ static int setup(struct spi_device *spi)
                 if (chip_info->cs_control)
                         chip->cs_control = chip_info->cs_control;
 
-                chip->timeout = (chip_info->timeout_microsecs * 10000) / 2712;
+                chip->timeout = SSP_TIMEOUT(chip_info->timeout_microsecs);
 
                 chip->threshold = SSCR1_RxTresh(chip_info->rx_threshold)
                                         | SSCR1_TxTresh(chip_info->tx_threshold);
@@ -1013,7 +1031,8 @@ static int setup(struct spi_device *spi)
 
         chip->cr0 = clk_div
                         | SSCR0_Motorola
-                        | SSCR0_DataSize(spi->bits_per_word & 0x0f)
+                        | SSCR0_DataSize(spi->bits_per_word > 16 ?
+                                spi->bits_per_word - 16 : spi->bits_per_word)
                         | SSCR0_SSE
                         | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0);
         chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) << 4)
@@ -1196,7 +1215,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
                 goto out_error_master_alloc;
         }
 
-        drv_data->ioaddr = (void *)io_p2v(memory_resource->start);
+        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->int_cr1 = SSCR1_TIE | SSCR1_RIE;
@@ -1218,7 +1237,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
                 goto out_error_master_alloc;
         }
 
-        status = request_irq(irq, ssp_int, SA_INTERRUPT, dev->bus_id, drv_data);
+        status = request_irq(irq, ssp_int, 0, dev->bus_id, drv_data);
         if (status < 0) {
                 dev_err(&pdev->dev, "can not get IRQ\n");
                 goto out_error_master_alloc;
diff --git a/include/asm-arm/arch-pxa/pxa2xx_spi.h b/include/asm-arm/arch-pxa/pxa2xx_spi.h
index 1e70908b816f..915590c391c8 100644
--- a/include/asm-arm/arch-pxa/pxa2xx_spi.h
+++ b/include/asm-arm/arch-pxa/pxa2xx_spi.h
@@ -27,13 +27,16 @@
 #define SSP1_SerClkDiv(x) (((CLOCK_SPEED_HZ/2/(x+1))<<8)&0x0000ff00)
 #define SSP2_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00)
 #define SSP3_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00)
+#define SSP_TIMEOUT_SCALE (2712)
 #elif defined(CONFIG_PXA27x)
 #define CLOCK_SPEED_HZ 13000000
 #define SSP1_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00)
 #define SSP2_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00)
 #define SSP3_SerClkDiv(x) (((CLOCK_SPEED_HZ/(x+1))<<8)&0x000fff00)
+#define SSP_TIMEOUT_SCALE (769)
 #endif
 
+#define SSP_TIMEOUT(x) ((x*10000)/SSP_TIMEOUT_SCALE)
 #define SSP1_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(1)))))
 #define SSP2_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(2)))))
 #define SSP3_VIRT ((void *)(io_p2v(__PREG(SSCR0_P(3)))))