spi: pxa2xx: Use core message processing loop

Convert the pump_transfers() transfer tasklet to transfer_one() hook the
SPI core calls to process single transfer instead of handling message
processing and chip select handling in the driver. This not only
simplifies the driver but also brings transfer statistics from the core.
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-pxa2xx-dma.c

@@ -51,19 +51,15 @@ static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data,
 		if (!pxa25x_ssp_comp(drv_data))
 			pxa2xx_spi_write(drv_data, SSTO, 0);
 
-		if (!error) {
-			msg->actual_length += drv_data->len;
-			msg->state = pxa2xx_spi_next_transfer(drv_data);
-		} else {
+		if (error) {
 			/* In case we got an error we disable the SSP now */
 			pxa2xx_spi_write(drv_data, SSCR0,
 					 pxa2xx_spi_read(drv_data, SSCR0)
 					 & ~SSCR0_SSE);
-
-			msg->state = ERROR_STATE;
+			msg->status = -EIO;
 		}
 
-		tasklet_schedule(&drv_data->pump_transfers);
+		spi_finalize_current_transfer(drv_data->master);
 	}
 }
 
@@ -74,11 +70,11 @@ static void pxa2xx_spi_dma_callback(void *data)
 
 static struct dma_async_tx_descriptor *
 pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
-			   enum dma_transfer_direction dir)
+			   enum dma_transfer_direction dir,
+			   struct spi_transfer *xfer)
 {
 	struct chip_data *chip =
 		spi_get_ctldata(drv_data->master->cur_msg->spi);
-	struct spi_transfer *xfer = drv_data->cur_transfer;
 	enum dma_slave_buswidth width;
 	struct dma_slave_config cfg;
 	struct dma_chan *chan;
@@ -144,12 +140,13 @@ irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data)
 	return IRQ_NONE;
 }
 
-int pxa2xx_spi_dma_prepare(struct driver_data *drv_data)
+int pxa2xx_spi_dma_prepare(struct driver_data *drv_data,
+			   struct spi_transfer *xfer)
 {
 	struct dma_async_tx_descriptor *tx_desc, *rx_desc;
 	int err;
 
-	tx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_MEM_TO_DEV);
+	tx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_MEM_TO_DEV, xfer);
 	if (!tx_desc) {
 		dev_err(&drv_data->pdev->dev,
 			"failed to get DMA TX descriptor\n");
@@ -157,7 +154,7 @@ int pxa2xx_spi_dma_prepare(struct driver_data *drv_data)
 		goto err_tx;
 	}
 
-	rx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_DEV_TO_MEM);
+	rx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_DEV_TO_MEM, xfer);
 	if (!rx_desc) {
 		dev_err(&drv_data->pdev->dev,
 			"failed to get DMA RX descriptor\n");
@@ -187,6 +184,13 @@ void pxa2xx_spi_dma_start(struct driver_data *drv_data)
 	atomic_set(&drv_data->dma_running, 1);
 }
 
+void pxa2xx_spi_dma_stop(struct driver_data *drv_data)
+{
+	atomic_set(&drv_data->dma_running, 0);
+	dmaengine_terminate_sync(drv_data->master->dma_rx);
+	dmaengine_terminate_sync(drv_data->master->dma_tx);
+}
+
 int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
 {
 	struct pxa2xx_spi_master *pdata = drv_data->master_info;

drivers/spi/spi-pxa2xx.h

@@ -46,15 +46,10 @@ struct driver_data {
 	u32 clear_sr;
 	u32 mask_sr;
 
-	/* Message Transfer pump */
-	struct tasklet_struct pump_transfers;
-
 	/* DMA engine support */
 	atomic_t dma_running;
 
-	/* Current message transfer state info */
-	struct spi_transfer *cur_transfer;
-	size_t len;
+	/* Current transfer state info */
 	void *tx;
 	void *tx_end;
 	void *rx;
@@ -104,11 +99,6 @@ static  inline void pxa2xx_spi_write(const struct driver_data *drv_data,
 	__raw_writel(val, drv_data->ioaddr + reg);
 }
 
-#define START_STATE ((void *)0)
-#define RUNNING_STATE ((void *)1)
-#define DONE_STATE ((void *)2)
-#define ERROR_STATE ((void *)-1)
-
 #define DMA_ALIGNMENT		8
 
 static inline int pxa25x_ssp_comp(struct driver_data *drv_data)
@@ -133,14 +123,15 @@ static inline void write_SSSR_CS(struct driver_data *drv_data, u32 val)
 }
 
 extern int pxa2xx_spi_flush(struct driver_data *drv_data);
-extern void *pxa2xx_spi_next_transfer(struct driver_data *drv_data);
 
 #define MAX_DMA_LEN		SZ_64K
 #define DEFAULT_DMA_CR1		(SSCR1_TSRE | SSCR1_RSRE | SSCR1_TRAIL)
 
 extern irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data);
-extern int pxa2xx_spi_dma_prepare(struct driver_data *drv_data);
+extern int pxa2xx_spi_dma_prepare(struct driver_data *drv_data,
+				  struct spi_transfer *xfer);
 extern void pxa2xx_spi_dma_start(struct driver_data *drv_data);
+extern void pxa2xx_spi_dma_stop(struct driver_data *drv_data);
 extern int pxa2xx_spi_dma_setup(struct driver_data *drv_data);
 extern void pxa2xx_spi_dma_release(struct driver_data *drv_data);
 extern int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,