[PATCH 0/3] Fixup mediatek spi driver

[PATCH 0/3] Fixup mediatek spi driver

[Leilk Liu]

Change in this patch:
1. revise coding styles.
2. delete redundant clock in prepare/unprepare_hardware.
3. fix incorrect endian usage on big-endian system.

Leilk Liu (3):
  spi: mediatek: revise coding style
  spi: mediatek: remove redundant clock in
    prepare_hardware/unprepare_hardware
  spi: mediatek: fix spi incorrect endian usage

 drivers/spi/spi-mt65xx.c                 | 169 +++++++++++++------------------
 include/linux/platform_data/spi-mt65xx.h |   2 -
 2 files changed, 73 insertions(+), 98 deletions(-)

--
1.8.1.1.dirty

[PATCH 1/3] spi: mediatek: revise coding style

[Leilk Liu]

This patch revises mediatek spi driver coding styles.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
---
 drivers/spi/spi-mt65xx.c | 125 ++++++++++++++++++++++++-----------------------
 1 file changed, 65 insertions(+), 60 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index c467ce0..814bca4 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -16,6 +16,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -48,15 +49,8 @@
 #define SPI_CFG1_PACKET_LOOP_MASK         0xff00
 #define SPI_CFG1_PACKET_LENGTH_MASK       0x3ff0000
 
-#define SPI_CMD_ACT_OFFSET                0
-#define SPI_CMD_RESUME_OFFSET             1
-#define SPI_CMD_CPHA_OFFSET               8
-#define SPI_CMD_CPOL_OFFSET               9
-#define SPI_CMD_TXMSBF_OFFSET             12
-#define SPI_CMD_RXMSBF_OFFSET             13
-#define SPI_CMD_RX_ENDIAN_OFFSET          14
-#define SPI_CMD_TX_ENDIAN_OFFSET          15
-
+#define SPI_CMD_ACT                  BIT(0)
+#define SPI_CMD_RESUME               BIT(1)
 #define SPI_CMD_RST                  BIT(2)
 #define SPI_CMD_PAUSE_EN             BIT(4)
 #define SPI_CMD_DEASSERT             BIT(5)
@@ -71,12 +65,10 @@
 #define SPI_CMD_FINISH_IE            BIT(16)
 #define SPI_CMD_PAUSE_IE             BIT(17)
 
-#define MTK_SPI_QUIRK_PAD_SELECT 1
-/* Must explicitly send dummy Tx bytes to do Rx only transfer */
-#define MTK_SPI_QUIRK_MUST_TX 1
-
 #define MT8173_SPI_MAX_PAD_SEL 3
 
+#define MTK_SPI_PAUSE_INT_STATUS 0x2
+
 #define MTK_SPI_IDLE 0
 #define MTK_SPI_PAUSED 1
 
@@ -84,8 +76,9 @@
 #define MTK_SPI_PACKET_SIZE 1024
 
 struct mtk_spi_compatible {
-	u32 need_pad_sel;
-	u32 must_tx;
+	bool need_pad_sel;
+	/* Must explicitly send dummy Tx bytes to do Rx only transfer */
+	bool must_tx;
 };
 
 struct mtk_spi {
@@ -100,19 +93,11 @@ struct mtk_spi {
 	const struct mtk_spi_compatible *dev_comp;
 };
 
-static const struct mtk_spi_compatible mt6589_compat = {
-	.need_pad_sel = 0,
-	.must_tx = 0,
-};
-
-static const struct mtk_spi_compatible mt8135_compat = {
-	.need_pad_sel = 0,
-	.must_tx = 0,
-};
-
+static const struct mtk_spi_compatible mt6589_compat;
+static const struct mtk_spi_compatible mt8135_compat;
 static const struct mtk_spi_compatible mt8173_compat = {
-	.need_pad_sel = MTK_SPI_QUIRK_PAD_SELECT,
-	.must_tx = MTK_SPI_QUIRK_MUST_TX,
+	.need_pad_sel = true,
+	.must_tx = true,
 };
 
 /*
@@ -156,14 +141,24 @@ static void mtk_spi_config(struct mtk_spi *mdata,
 	reg_val = readl(mdata->base + SPI_CMD_REG);
 
 	/* set the mlsbx and mlsbtx */
-	reg_val &= ~(SPI_CMD_TXMSBF | SPI_CMD_RXMSBF);
-	reg_val |= (chip_config->tx_mlsb << SPI_CMD_TXMSBF_OFFSET);
-	reg_val |= (chip_config->rx_mlsb << SPI_CMD_RXMSBF_OFFSET);
+	if (chip_config->tx_mlsb)
+		reg_val |= SPI_CMD_TXMSBF;
+	else
+		reg_val &= ~SPI_CMD_TXMSBF;
+	if (chip_config->rx_mlsb)
+		reg_val |= SPI_CMD_RXMSBF;
+	else
+		reg_val &= ~SPI_CMD_RXMSBF;
 
 	/* set the tx/rx endian */
-	reg_val &= ~(SPI_CMD_TX_ENDIAN | SPI_CMD_RX_ENDIAN);
-	reg_val |= (chip_config->tx_endian << SPI_CMD_TX_ENDIAN_OFFSET);
-	reg_val |= (chip_config->rx_endian << SPI_CMD_RX_ENDIAN_OFFSET);
+	if (chip_config->tx_endian)
+		reg_val |= SPI_CMD_TX_ENDIAN;
+	else
+		reg_val &= ~SPI_CMD_TX_ENDIAN;
+	if (chip_config->rx_endian)
+		reg_val |= SPI_CMD_RX_ENDIAN;
+	else
+		reg_val &= ~SPI_CMD_RX_ENDIAN;
 
 	/* set finish and pause interrupt always enable */
 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_EN;
@@ -196,7 +191,7 @@ static int mtk_spi_prepare_hardware(struct spi_master *master)
 
 	trans = list_first_entry(&msg->transfers, struct spi_transfer,
 				 transfer_list);
-	if (trans->cs_change == 0) {
+	if (!trans->cs_change) {
 		mdata->state = MTK_SPI_IDLE;
 		mtk_spi_reset(mdata);
 	}
@@ -226,9 +221,14 @@ static int mtk_spi_prepare_message(struct spi_master *master,
 	cpol = spi->mode & SPI_CPOL ? 1 : 0;
 
 	reg_val = readl(mdata->base + SPI_CMD_REG);
-	reg_val &= ~(SPI_CMD_CPHA | SPI_CMD_CPOL);
-	reg_val |= (cpha << SPI_CMD_CPHA_OFFSET);
-	reg_val |= (cpol << SPI_CMD_CPOL_OFFSET);
+	if (cpha)
+		reg_val |= SPI_CMD_CPHA;
+	else
+		reg_val &= ~SPI_CMD_CPHA;
+	if (cpol)
+		reg_val |= SPI_CMD_CPOL;
+	else
+		reg_val &= ~SPI_CMD_CPOL;
 	writel(reg_val, mdata->base + SPI_CMD_REG);
 
 	chip_config = spi->controller_data;
@@ -257,8 +257,7 @@ static void mtk_spi_set_cs(struct spi_device *spi, bool enable)
 static void mtk_spi_prepare_transfer(struct spi_master *master,
 				     struct spi_transfer *xfer)
 {
-	u32 spi_clk_hz, div, high_time, low_time, holdtime,
-	    setuptime, cs_idletime, reg_val = 0;
+	u32 spi_clk_hz, div, sck_time, cs_time, reg_val = 0;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
 	spi_clk_hz = clk_get_rate(mdata->spi_clk);
@@ -267,21 +266,18 @@ static void mtk_spi_prepare_transfer(struct spi_master *master,
 	else
 		div = 1;
 
-	high_time = (div + 1) / 2;
-	low_time = (div + 1) / 2;
-	holdtime = (div + 1) / 2 * 2;
-	setuptime = (div + 1) / 2 * 2;
-	cs_idletime = (div + 1) / 2 * 2;
+	sck_time = (div + 1) / 2;
+	cs_time = sck_time * 2;
 
-	reg_val |= (((high_time - 1) & 0xff) << SPI_CFG0_SCK_HIGH_OFFSET);
-	reg_val |= (((low_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
-	reg_val |= (((holdtime - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
-	reg_val |= (((setuptime - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
+	reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_HIGH_OFFSET);
+	reg_val |= (((sck_time - 1) & 0xff) << SPI_CFG0_SCK_LOW_OFFSET);
+	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_HOLD_OFFSET);
+	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG0_CS_SETUP_OFFSET);
 	writel(reg_val, mdata->base + SPI_CFG0_REG);
 
 	reg_val = readl(mdata->base + SPI_CFG1_REG);
 	reg_val &= ~SPI_CFG1_CS_IDLE_MASK;
-	reg_val |= (((cs_idletime - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
+	reg_val |= (((cs_time - 1) & 0xff) << SPI_CFG1_CS_IDLE_OFFSET);
 	writel(reg_val, mdata->base + SPI_CFG1_REG);
 }
 
@@ -290,11 +286,11 @@ static void mtk_spi_setup_packet(struct spi_master *master)
 	u32 packet_size, packet_loop, reg_val;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
-	packet_size = min_t(unsigned, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
+	packet_size = min_t(u32, mdata->xfer_len, MTK_SPI_PACKET_SIZE);
 	packet_loop = mdata->xfer_len / packet_size;
 
 	reg_val = readl(mdata->base + SPI_CFG1_REG);
-	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK + SPI_CFG1_PACKET_LOOP_MASK);
+	reg_val &= ~(SPI_CFG1_PACKET_LENGTH_MASK | SPI_CFG1_PACKET_LOOP_MASK);
 	reg_val |= (packet_size - 1) << SPI_CFG1_PACKET_LENGTH_OFFSET;
 	reg_val |= (packet_loop - 1) << SPI_CFG1_PACKET_LOOP_OFFSET;
 	writel(reg_val, mdata->base + SPI_CFG1_REG);
@@ -302,20 +298,20 @@ static void mtk_spi_setup_packet(struct spi_master *master)
 
 static void mtk_spi_enable_transfer(struct spi_master *master)
 {
-	int cmd;
+	u32 cmd;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
 	cmd = readl(mdata->base + SPI_CMD_REG);
 	if (mdata->state == MTK_SPI_IDLE)
-		cmd |= 1 << SPI_CMD_ACT_OFFSET;
+		cmd |= SPI_CMD_ACT;
 	else
-		cmd |= 1 << SPI_CMD_RESUME_OFFSET;
+		cmd |= SPI_CMD_RESUME;
 	writel(cmd, mdata->base + SPI_CMD_REG);
 }
 
-static int mtk_spi_get_mult_delta(int xfer_len)
+static int mtk_spi_get_mult_delta(u32 xfer_len)
 {
-	int mult_delta;
+	u32 mult_delta;
 
 	if (xfer_len > MTK_SPI_PACKET_SIZE)
 		mult_delta = xfer_len % MTK_SPI_PACKET_SIZE;
@@ -459,7 +455,7 @@ static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 	struct spi_transfer *trans = mdata->cur_transfer;
 
 	reg_val = readl(mdata->base + SPI_STATUS0_REG);
-	if (reg_val & 0x2)
+	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
 		mdata->state = MTK_SPI_PAUSED;
 	else
 		mdata->state = MTK_SPI_IDLE;
@@ -527,7 +523,7 @@ static int mtk_spi_probe(struct platform_device *pdev)
 	struct mtk_spi *mdata;
 	const struct of_device_id *of_id;
 	struct resource *res;
-	int	irq, ret;
+	int irq, ret;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(*mdata));
 	if (!master) {
@@ -693,8 +689,10 @@ static int mtk_spi_resume(struct device *dev)
 
 	if (!pm_runtime_suspended(dev)) {
 		ret = clk_prepare_enable(mdata->spi_clk);
-		if (ret < 0)
+		if (ret < 0) {
+			dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
 			return ret;
+		}
 	}
 
 	ret = spi_master_resume(master);
@@ -720,8 +718,15 @@ static int mtk_spi_runtime_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
+	int ret;
 
-	return clk_prepare_enable(mdata->spi_clk);
+	ret = clk_prepare_enable(mdata->spi_clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable spi_clk (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
 }
 #endif /* CONFIG_PM */
 
-- 
1.8.1.1.dirty

[PATCH 1/3] spi: mediatek: revise coding style

[Mark Brown]

On Wed, Aug 19, 2015 at 11:37:56AM +0800, Leilk Liu wrote:
> This patch revises mediatek spi driver coding styles.

Two problems here.  One is that it's best practice to make purely
stylistic changes after any substantial ones, that way people can pick
up bug fixes without needing the stylistic changes.  The other is that
this just isn't an adequate changelog - what are the revisions that are
being made to the coding style and why are they being made?  This is a
very large change and there seem to be many different and unrelated
changes being made here.
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[PATCH 2/3] spi: mediatek: remove redundant clock in prepare_hardware/unprepare_hardware

[Leilk Liu]

clock in prepare_hardware/unprepare_hardware is redundant
with pm_runtime, so remove them.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
---
 drivers/spi/spi-mt65xx.c | 17 -----------------
 1 file changed, 17 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 814bca4..1c2b215 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -181,13 +181,6 @@ static int mtk_spi_prepare_hardware(struct spi_master *master)
 	struct spi_transfer *trans;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 	struct spi_message *msg = master->cur_msg;
-	int ret;
-
-	ret = clk_prepare_enable(mdata->spi_clk);
-	if (ret < 0) {
-		dev_err(&master->dev, "failed to enable clock (%d)\n", ret);
-		return ret;
-	}
 
 	trans = list_first_entry(&msg->transfers, struct spi_transfer,
 				 transfer_list);
@@ -196,15 +189,6 @@ static int mtk_spi_prepare_hardware(struct spi_master *master)
 		mtk_spi_reset(mdata);
 	}
 
-	return ret;
-}
-
-static int mtk_spi_unprepare_hardware(struct spi_master *master)
-{
-	struct mtk_spi *mdata = spi_master_get_devdata(master);
-
-	clk_disable_unprepare(mdata->spi_clk);
-
 	return 0;
 }
 
@@ -537,7 +521,6 @@ static int mtk_spi_probe(struct platform_device *pdev)
 
 	master->set_cs = mtk_spi_set_cs;
 	master->prepare_transfer_hardware = mtk_spi_prepare_hardware;
-	master->unprepare_transfer_hardware = mtk_spi_unprepare_hardware;
 	master->prepare_message = mtk_spi_prepare_message;
 	master->transfer_one = mtk_spi_transfer_one;
 	master->can_dma = mtk_spi_can_dma;
-- 
1.8.1.1.dirty

[PATCH 3/3] spi: mediatek: fix spi incorrect endian usage

[Leilk Liu]

TX_ENDIAN/RX_ENDIAN bits define whether to reverse the endian
order of the data DMA from/to memory. The endian order should
keep the same with cpu endian.

Signed-off-by: Leilk Liu <leilk.liu@mediatek.com>
---
 drivers/spi/spi-mt65xx.c                 | 43 ++++++++++++--------------------
 include/linux/platform_data/spi-mt65xx.h |  2 --
 2 files changed, 16 insertions(+), 29 deletions(-)

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 1c2b215..eaadc7e 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -107,8 +107,6 @@ static const struct mtk_spi_compatible mt8173_compat = {
 static const struct mtk_chip_config mtk_default_chip_info = {
 	.rx_mlsb = 1,
 	.tx_mlsb = 1,
-	.tx_endian = 0,
-	.rx_endian = 0,
 };
 
 static const struct of_device_id mtk_spi_of_match[] = {
@@ -151,14 +149,13 @@ static void mtk_spi_config(struct mtk_spi *mdata,
 		reg_val &= ~SPI_CMD_RXMSBF;
 
 	/* set the tx/rx endian */
-	if (chip_config->tx_endian)
-		reg_val |= SPI_CMD_TX_ENDIAN;
-	else
-		reg_val &= ~SPI_CMD_TX_ENDIAN;
-	if (chip_config->rx_endian)
-		reg_val |= SPI_CMD_RX_ENDIAN;
-	else
-		reg_val &= ~SPI_CMD_RX_ENDIAN;
+#ifdef __LITTLE_ENDIAN
+	reg_val &= ~SPI_CMD_TX_ENDIAN;
+	reg_val &= ~SPI_CMD_RX_ENDIAN;
+#else
+	reg_val |= SPI_CMD_TX_ENDIAN;
+	reg_val |= SPI_CMD_RX_ENDIAN;
+#endif
 
 	/* set finish and pause interrupt always enable */
 	reg_val |= SPI_CMD_FINISH_IE | SPI_CMD_PAUSE_EN;
@@ -348,7 +345,7 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
 				 struct spi_device *spi,
 				 struct spi_transfer *xfer)
 {
-	int cnt, i;
+	int cnt;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 
 	mdata->cur_transfer = xfer;
@@ -360,10 +357,7 @@ static int mtk_spi_fifo_transfer(struct spi_master *master,
 		cnt = xfer->len / 4 + 1;
 	else
 		cnt = xfer->len / 4;
-
-	for (i = 0; i < cnt; i++)
-		writel(*((u32 *)xfer->tx_buf + i),
-		       mdata->base + SPI_TX_DATA_REG);
+	iowrite32_rep(mdata->base + SPI_TX_DATA_REG, xfer->tx_buf, cnt);
 
 	mtk_spi_enable_transfer(master);
 
@@ -433,7 +427,7 @@ static bool mtk_spi_can_dma(struct spi_master *master,
 
 static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 {
-	u32 cmd, reg_val, i;
+	u32 cmd, reg_val, cnt;
 	struct spi_master *master = dev_id;
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
 	struct spi_transfer *trans = mdata->cur_transfer;
@@ -445,18 +439,13 @@ static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 		mdata->state = MTK_SPI_IDLE;
 
 	if (!master->can_dma(master, master->cur_msg->spi, trans)) {
-		/* xfer len is not N*4 bytes every time in a transfer,
-		 * but SPI_RX_DATA_REG must reads 4 bytes once,
-		 * so rx buffer byte by byte.
-		 */
 		if (trans->rx_buf) {
-			for (i = 0; i < mdata->xfer_len; i++) {
-				if (i % 4 == 0)
-					reg_val =
-					readl(mdata->base + SPI_RX_DATA_REG);
-				*((u8 *)(trans->rx_buf + i)) =
-					(reg_val >> ((i % 4) * 8)) & 0xff;
-			}
+			if (mdata->xfer_len % 4)
+				cnt = mdata->xfer_len / 4 + 1;
+			else
+				cnt = mdata->xfer_len / 4;
+			ioread32_rep(mdata->base + SPI_RX_DATA_REG,
+				     trans->rx_buf, cnt);
 		}
 		spi_finalize_current_transfer(master);
 		return IRQ_HANDLED;
diff --git a/include/linux/platform_data/spi-mt65xx.h b/include/linux/platform_data/spi-mt65xx.h
index 7512255..54b0448 100644
--- a/include/linux/platform_data/spi-mt65xx.h
+++ b/include/linux/platform_data/spi-mt65xx.h
@@ -16,7 +16,5 @@
 struct mtk_chip_config {
 	u32 tx_mlsb;
 	u32 rx_mlsb;
-	u32 tx_endian;
-	u32 rx_endian;
 };
 #endif
-- 
1.8.1.1.dirty

[PATCH 3/3] spi: mediatek: fix spi incorrect endian usage

[Mark Brown]

On Wed, Aug 19, 2015 at 11:37:58AM +0800, Leilk Liu wrote:
> TX_ENDIAN/RX_ENDIAN bits define whether to reverse the endian
> order of the data DMA from/to memory. The endian order should
> keep the same with cpu endian.

This doesn't apply, probably because it depends on your stylistic
changes patch - this is an example of the issues I was mentioning with
stylistic changes getting in the waty of fixes :(
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