[PATCH 3/3] spi: pxa2xx: Use dummy buffers provided by SPI core

[Jarkko Nikula <jarkko.nikula-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

Dummy buffer is used for half duplex transfers that don't have TX or RX
buffer set. Instead of own dummy buffer management here let the SPI core to
handle it by setting the SPI_MASTER_MUST_RX and SPI_MASTER_MUST_TX flags.
Then core makes sure both transfer buffers are set.

Signed-off-by: Jarkko Nikula <jarkko.nikula-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-pxa2xx-dma.c | 10 +---------
 drivers/spi/spi-pxa2xx.c     |  1 +
 drivers/spi/spi-pxa2xx.h     |  1 -
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/spi/spi-pxa2xx-dma.c b/drivers/spi/spi-pxa2xx-dma.c
index 696a340230eb..bef707f7ae99 100644
--- a/drivers/spi/spi-pxa2xx-dma.c
+++ b/drivers/spi/spi-pxa2xx-dma.c
@@ -53,11 +53,7 @@ static int pxa2xx_spi_map_dma_buffer(struct driver_data *drv_data,
 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 		size_t bytes = min_t(size_t, len, SZ_2K);
 
-		if (buf)
-			sg_set_buf(sg, pbuf, bytes);
-		else
-			sg_set_buf(sg, drv_data->dummy, bytes);
-
+		sg_set_buf(sg, pbuf, bytes);
 		pbuf += bytes;
 		len -= bytes;
 	}
@@ -303,10 +299,6 @@ int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	drv_data->dummy = devm_kzalloc(dev, SZ_2K, GFP_KERNEL);
-	if (!drv_data->dummy)
-		return -ENOMEM;
-
 	drv_data->tx_chan = dma_request_slave_channel_compat(mask,
 				pdata->dma_filter, pdata->tx_param, dev, "tx");
 	if (!drv_data->tx_chan)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 47bdbd350a24..86c155aea0cf 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1562,6 +1562,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
 	master->unprepare_transfer_hardware = pxa2xx_spi_unprepare_transfer;
 	master->fw_translate_cs = pxa2xx_spi_fw_translate_cs;
 	master->auto_runtime_pm = true;
+	master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX;
 
 	drv_data->ssp_type = ssp->type;
 
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 85017f9ca67c..e6b09000ff14 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -56,7 +56,6 @@ struct driver_data {
 	struct sg_table tx_sgt;
 	int rx_nents;
 	int tx_nents;
-	void *dummy;
 	atomic_t dma_running;
 
 	/* Current message transfer state info */
-- 
2.7.0

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