[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>

diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c
index 596bf820b70c655b9720093e81936ec25f393d99..29aec77f98be53a758311f78d71cc86c26ec7a64 100644 (file)
--- 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 1e70908b816f59b1bf172c9445d294c6aab3bb81..915590c391c8c8a4f6f7972912e7ce3cbf247d5c 100644 (file)
--- 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)))))