From 0dfbaa8932a6c4ffd83a6459f247bf06b4652543 Mon Sep 17 00:00:00 2001
From: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Date: Sat, 5 Dec 2015 17:57:01 +0100
Subject: spi: imx: replace multiple watermarks with single for RX, TX and RXT

There is no need to have different watermarks levels since they are the same.
Merge them into one WML parameter.

Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index e6b1c74..beba40b 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -104,9 +104,7 @@ struct spi_imx_data {
 	unsigned int dma_is_inited;
 	unsigned int dma_finished;
 	bool usedma;
-	u32 rx_wml;
-	u32 tx_wml;
-	u32 rxt_wml;
+	u32 wml;
 	struct completion dma_rx_completion;
 	struct completion dma_tx_completion;
 
@@ -201,9 +199,8 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
 
-	if (spi_imx->dma_is_inited
-	    && transfer->len > spi_imx->rx_wml * sizeof(u32)
-	    && transfer->len > spi_imx->tx_wml * sizeof(u32))
+	if (spi_imx->dma_is_inited &&
+	    transfer->len > spi_imx->wml * sizeof(u32))
 		return true;
 	return false;
 }
@@ -388,10 +385,9 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
 	if (spi_imx->dma_is_inited) {
 		dma = readl(spi_imx->base + MX51_ECSPI_DMA);
 
-		spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
-		rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
-		tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
-		rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
+		rx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
+		tx_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
+		rxt_wml_cfg = spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
 		dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
 			   & ~MX51_ECSPI_DMA_RX_WML_MASK
 			   & ~MX51_ECSPI_DMA_RXT_WML_MASK)
@@ -842,6 +838,8 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		return 0;
 
+	spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2;
+
 	/* Prepare for TX DMA: */
 	master->dma_tx = dma_request_slave_channel(dev, "tx");
 	if (!master->dma_tx) {
@@ -853,7 +851,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	slave_config.direction = DMA_MEM_TO_DEV;
 	slave_config.dst_addr = res->start + MXC_CSPITXDATA;
 	slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+	slave_config.dst_maxburst = spi_imx->wml;
 	ret = dmaengine_slave_config(master->dma_tx, &slave_config);
 	if (ret) {
 		dev_err(dev, "error in TX dma configuration.\n");
@@ -871,7 +869,7 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	slave_config.direction = DMA_DEV_TO_MEM;
 	slave_config.src_addr = res->start + MXC_CSPIRXDATA;
 	slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
+	slave_config.src_maxburst = spi_imx->wml;
 	ret = dmaengine_slave_config(master->dma_rx, &slave_config);
 	if (ret) {
 		dev_err(dev, "error in RX dma configuration.\n");
@@ -884,8 +882,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
 	master->max_dma_len = MAX_SDMA_BD_BYTES;
 	spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
 					 SPI_MASTER_MUST_TX;
-	spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
-	spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
 	spi_imx->dma_is_inited = 1;
 
 	return 0;
@@ -952,7 +948,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 	dma = readl(spi_imx->base + MX51_ECSPI_DMA);
 	dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
 	/* Change RX_DMA_LENGTH trigger dma fetch tail data */
-	left = transfer->len % spi_imx->rxt_wml;
+	left = transfer->len % spi_imx->wml;
 	if (left)
 		writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
 				spi_imx->base + MX51_ECSPI_DMA);
@@ -987,8 +983,9 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 			spi_imx->devtype_data->reset(spi_imx);
 			dmaengine_terminate_all(master->dma_rx);
 		}
+		dma &= ~MX51_ECSPI_DMA_RXT_WML_MASK;
 		writel(dma |
-		       spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
+		       spi_imx->wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
 		       spi_imx->base + MX51_ECSPI_DMA);
 	}
 
-- 
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