diff mbox

[v5,3/3] I2C: mediatek: Add driver for MediaTek MT8173 I2C controller

Message ID 1426917922-61356-4-git-send-email-eddie.huang@mediatek.com (mailing list archive)
State New, archived
Headers show

Commit Message

Eddie Huang March 21, 2015, 6:05 a.m. UTC
Add mediatek MT8173 I2C controller driver. Compare to I2C controller
of earlier mediatek SoC, MT8173 fix write-then-read limitation, and
also increase message size to 64kb.

Signed-off-by: Xudong Chen <xudong.chen@mediatek.com>
Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 107 ++++++++++++++++++++++++++++------------
 1 file changed, 75 insertions(+), 32 deletions(-)

Comments

Sascha Hauer March 23, 2015, 7:39 a.m. UTC | #1
On Sat, Mar 21, 2015 at 02:05:22PM +0800, Eddie Huang wrote:
> Add mediatek MT8173 I2C controller driver. Compare to I2C controller
> of earlier mediatek SoC, MT8173 fix write-then-read limitation, and
> also increase message size to 64kb.
> 

[...]

> +static const struct i2c_adapter_quirks mt8173_i2c_quirks = {
> +	.max_num_msgs = MAX_MSG_NUM_MT8173,
> +	.max_write_len = MAX_DMA_TRANS_SIZE_MT8173,
> +	.max_read_len = MAX_DMA_TRANS_SIZE_MT8173,
> +	.max_comb_1st_msg_len = MAX_DMA_TRANS_SIZE_MT8173,
> +	.max_comb_2nd_msg_len = MAX_WRRD_TRANS_SIZE_MT8173,
> +};
> +
>  static int mtk_i2c_probe(struct platform_device *pdev)
>  {
>  	int ret = 0;
> @@ -587,7 +626,8 @@ static int mtk_i2c_probe(struct platform_device *pdev)
>  		return -EINVAL;
>  
>  	i2c->platform_compat = mtk_get_device_prop(pdev);
> -	if (i2c->have_pmic && (i2c->platform_compat & COMPAT_MT6577))
> +	if (i2c->have_pmic && (i2c->platform_compat &
> +			(COMPAT_MT6577 | COMPAT_MT8173)))
>  		return -EINVAL;
>  
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> @@ -613,7 +653,10 @@ static int mtk_i2c_probe(struct platform_device *pdev)
>  	i2c->adap.dev.parent = &pdev->dev;
>  	i2c->adap.owner = THIS_MODULE;
>  	i2c->adap.algo = &mtk_i2c_algorithm;
> -	i2c->adap.quirks = &mt6577_i2c_quirks;
> +	if (i2c->platform_compat & COMPAT_MT8173)
> +		i2c->adap.quirks = &mt8173_i2c_quirks;
> +	else
> +		i2c->adap.quirks = &mt6577_i2c_quirks;

Instead of putting an integer into struct of_device_id you should
introduce a

struct mtk_i2c_data {
	struct i2c_adapter_quirks quirks;
	int compat;
	/* Additional SoC specific data */
};

and put a pointer to this directly into the of_device_id. This way you
need less casting and can put newly discovered differences diretly into
some data struct and don't have to introduce if(socxy) ... else ...
everytime.

Sascha
Eddie Huang March 30, 2015, 8:05 a.m. UTC | #2
Hi Sascha,

On Mon, 2015-03-23 at 08:39 +0100, Sascha Hauer wrote:
> On Sat, Mar 21, 2015 at 02:05:22PM +0800, Eddie Huang wrote:
> > Add mediatek MT8173 I2C controller driver. Compare to I2C controller
> > of earlier mediatek SoC, MT8173 fix write-then-read limitation, and
> > also increase message size to 64kb.
> > 
> 
> [...]
> 
> > +static const struct i2c_adapter_quirks mt8173_i2c_quirks = {
> > +	.max_num_msgs = MAX_MSG_NUM_MT8173,
> > +	.max_write_len = MAX_DMA_TRANS_SIZE_MT8173,
> > +	.max_read_len = MAX_DMA_TRANS_SIZE_MT8173,
> > +	.max_comb_1st_msg_len = MAX_DMA_TRANS_SIZE_MT8173,
> > +	.max_comb_2nd_msg_len = MAX_WRRD_TRANS_SIZE_MT8173,
> > +};
> > +
> >  static int mtk_i2c_probe(struct platform_device *pdev)
> >  {
> >  	int ret = 0;
> > @@ -587,7 +626,8 @@ static int mtk_i2c_probe(struct platform_device *pdev)
> >  		return -EINVAL;
> >  
> >  	i2c->platform_compat = mtk_get_device_prop(pdev);
> > -	if (i2c->have_pmic && (i2c->platform_compat & COMPAT_MT6577))
> > +	if (i2c->have_pmic && (i2c->platform_compat &
> > +			(COMPAT_MT6577 | COMPAT_MT8173)))
> >  		return -EINVAL;
> >  
> >  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > @@ -613,7 +653,10 @@ static int mtk_i2c_probe(struct platform_device *pdev)
> >  	i2c->adap.dev.parent = &pdev->dev;
> >  	i2c->adap.owner = THIS_MODULE;
> >  	i2c->adap.algo = &mtk_i2c_algorithm;
> > -	i2c->adap.quirks = &mt6577_i2c_quirks;
> > +	if (i2c->platform_compat & COMPAT_MT8173)
> > +		i2c->adap.quirks = &mt8173_i2c_quirks;
> > +	else
> > +		i2c->adap.quirks = &mt6577_i2c_quirks;
> 
> Instead of putting an integer into struct of_device_id you should
> introduce a
> 
> struct mtk_i2c_data {
> 	struct i2c_adapter_quirks quirks;
> 	int compat;
> 	/* Additional SoC specific data */
> };
> 
> and put a pointer to this directly into the of_device_id. This way you
> need less casting and can put newly discovered differences diretly into
> some data struct and don't have to introduce if(socxy) ... else ...
> everytime.
> 

Thanks your suggestion. I will use capability struct like 

struct mtk_i2c_compatible {
	unsigned char pmic_i2c;
	unsigned char dcm;
	unsigned char auto_restart;
	const struct i2c_adapter_quirks *quirks;
};

And pass in of_device_id, then remove all if(socxy).... else ... in
driver.

Eddie
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 3940112..17607c8 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -33,10 +33,13 @@ 
 #include <linux/of_irq.h>
 #include <linux/clk.h>
 
+#define I2C_RS_TRANSFER			(1 << 4)
 #define I2C_HS_NACKERR			(1 << 2)
 #define I2C_ACKERR			(1 << 1)
 #define I2C_TRANSAC_COMP		(1 << 0)
 #define I2C_TRANSAC_START		(1 << 0)
+#define I2C_RS_MUL_CNFG			(1 << 15)
+#define I2C_RS_MUL_TRIG			(1 << 14)
 #define I2C_TIMING_STEP_DIV_MASK	(0x3f << 0)
 #define I2C_TIMING_SAMPLE_COUNT_MASK	(0x7 << 0)
 #define I2C_TIMING_SAMPLE_DIV_MASK	(0x7 << 8)
@@ -67,6 +70,9 @@ 
 #define MAX_MSG_NUM_MT6577		1
 #define MAX_DMA_TRANS_SIZE_MT6577	255
 #define MAX_WRRD_TRANS_SIZE_MT6577	31
+#define MAX_MSG_NUM_MT8173		65535
+#define MAX_DMA_TRANS_SIZE_MT8173	65535
+#define MAX_WRRD_TRANS_SIZE_MT8173	65535
 #define MAX_SAMPLE_CNT_DIV		8
 #define MAX_STEP_CNT_DIV		64
 #define MAX_HS_STEP_CNT_DIV		8
@@ -81,6 +87,7 @@ 
 
 #define COMPAT_MT6577			(0x1 << 0)
 #define COMPAT_MT6589			(0x1 << 1)
+#define COMPAT_MT8173			(0x1 << 2)
 
 #define I2C_DRV_NAME		"mt-i2c"
 
@@ -172,6 +179,7 @@  struct mtk_i2c {
 static const struct of_device_id mtk_i2c_of_match[] = {
 	{ .compatible = "mediatek,mt6577-i2c", .data = (void *)COMPAT_MT6577 },
 	{ .compatible = "mediatek,mt6589-i2c", .data = (void *)COMPAT_MT6589 },
+	{ .compatible = "mediatek,mt8173-i2c", .data = (void *)COMPAT_MT8173 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mtk_i2c_match);
@@ -236,7 +244,7 @@  static inline void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 	else
 		mtk_i2c_writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c, OFFSET_IO_CONFIG);
 
-	if (i2c->platform_compat & COMPAT_MT6577)
+	if (i2c->platform_compat & (COMPAT_MT6577 | COMPAT_MT8173))
 		mtk_i2c_writew(I2C_DCM_DISABLE, i2c, OFFSET_DCM_EN);
 
 	mtk_i2c_writew(i2c->timing_reg, i2c, OFFSET_TIMING);
@@ -320,10 +328,12 @@  static int i2c_set_speed(struct mtk_i2c *i2c, unsigned int clk_src_in_hz)
 	return 0;
 }
 
-static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
+static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
+					int num, int left_num)
 {
 	u16 addr_reg;
 	u16 control_reg;
+	u16 start_reg = 0;
 	u16 irqstat;
 	dma_addr_t rpaddr = 0;
 	dma_addr_t wpaddr = 0;
@@ -344,6 +354,8 @@  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
 		control_reg |= I2C_CONTROL_RS;
 	if (i2c->op == I2C_MASTER_WRRD)
 		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
+	if (left_num >= 1)
+		control_reg |= I2C_CONTROL_RS;
 	mtk_i2c_writew(control_reg, i2c, OFFSET_CONTROL);
 
 	/* set start condition */
@@ -361,13 +373,13 @@  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
 	mtk_i2c_writew(addr_reg, i2c, OFFSET_SLAVE_ADDR);
 
 	/* Clear interrupt status */
-	mtk_i2c_writew(I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP,
-		i2c, OFFSET_INTR_STAT);
+	mtk_i2c_writew(I2C_RS_TRANSFER | I2C_HS_NACKERR | I2C_ACKERR
+			| I2C_TRANSAC_COMP, i2c, OFFSET_INTR_STAT);
 	mtk_i2c_writew(I2C_FIFO_ADDR_CLR, i2c, OFFSET_FIFO_ADDR_CLR);
 
 	/* Enable interrupt */
-	mtk_i2c_writew(I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP,
-		i2c, OFFSET_INTR_MASK);
+	mtk_i2c_writew(I2C_RS_TRANSFER | I2C_HS_NACKERR | I2C_ACKERR
+			| I2C_TRANSAC_COMP, i2c, OFFSET_INTR_MASK);
 
 	/* Set transfer and transaction len */
 	if (i2c->op == I2C_MASTER_WRRD) {
@@ -376,7 +388,7 @@  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
 		mtk_i2c_writew(I2C_WRRD_TRANAC_VALUE, i2c, OFFSET_TRANSAC_LEN);
 	} else {
 		mtk_i2c_writew(msgs->len, i2c, OFFSET_TRANSFER_LEN);
-		mtk_i2c_writew(I2C_RD_TRANAC_VALUE, i2c, OFFSET_TRANSAC_LEN);
+		mtk_i2c_writew(num, i2c, OFFSET_TRANSAC_LEN);
 	}
 
 	/* Prepare buffer data to start transfer */
@@ -422,7 +434,17 @@  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
 	/* flush before sending start */
 	mb();
 	mtk_i2c_writel_dma(I2C_DMA_START_EN, i2c, OFFSET_EN);
-	mtk_i2c_writew(I2C_TRANSAC_START, i2c, OFFSET_START);
+
+	if (i2c->platform_compat & (COMPAT_MT6577 | COMPAT_MT6589)) {
+		start_reg = I2C_TRANSAC_START;
+	} else if (i2c->platform_compat & COMPAT_MT8173) {
+		if (left_num >= 1)
+			start_reg = I2C_TRANSAC_START | I2C_RS_MUL_CNFG
+					| I2C_RS_MUL_TRIG;
+		else
+			start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG;
+	}
+	mtk_i2c_writew(start_reg, i2c, OFFSET_START);
 
 	tmo = wait_event_timeout(i2c->wait, i2c->trans_stop, tmo);
 
@@ -455,6 +477,10 @@  static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs)
 		return -EREMOTEIO;
 	}
 
+	if (irqstat & I2C_RS_TRANSFER)
+		dev_dbg(i2c->dev, "addr: %x, restart transfer interrupt.\n",
+				msgs->addr);
+
 	return 0;
 }
 
@@ -469,28 +495,33 @@  static int mtk_i2c_transfer(struct i2c_adapter *adap,
 	if (ret)
 		return ret;
 
-	if (msgs->buf == NULL) {
-		dev_dbg(i2c->dev, "data buffer is NULL.\n");
-		ret = -EINVAL;
-		goto err_exit;
-	}
-
-	if (msgs->flags & I2C_M_RD)
-		i2c->op = I2C_MASTER_RD;
-	else
-		i2c->op = I2C_MASTER_WR;
+	while (left_num--) {
+		if (msgs->buf == NULL) {
+			dev_dbg(i2c->dev, "data buffer is NULL.\n");
+			ret = -EINVAL;
+			goto err_exit;
+		}
 
-	if (num > 1) {
-		/* combined two messages into one transaction */
-		i2c->op = I2C_MASTER_WRRD;
-		left_num--;
-	}
+		if (msgs->flags & I2C_M_RD)
+			i2c->op = I2C_MASTER_RD;
+		else
+			i2c->op = I2C_MASTER_WR;
+
+		if (i2c->platform_compat & (COMPAT_MT6577 | COMPAT_MT6589)) {
+			if (num > 1) {
+				/* combined two messages into one transaction */
+				i2c->op = I2C_MASTER_WRRD;
+				left_num--;
+			}
+		}
 
-	/* always use DMA mode. */
-	ret = mtk_i2c_do_transfer(i2c, msgs);
-	if (ret < 0)
-		goto err_exit;
+		/* always use DMA mode. */
+		ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num);
+		if (ret < 0)
+			goto err_exit;
 
+		msgs++;
+	}
 	/* the return value is number of executed messages */
 	ret = num;
 
@@ -504,14 +535,14 @@  static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 	struct mtk_i2c *i2c = dev_id;
 
 	/* Clear interrupt mask */
-	mtk_i2c_writew(~(I2C_HS_NACKERR | I2C_ACKERR | I2C_TRANSAC_COMP),
-		i2c, OFFSET_INTR_MASK);
+	mtk_i2c_writew(~(I2C_RS_TRANSFER | I2C_HS_NACKERR | I2C_ACKERR
+			| I2C_TRANSAC_COMP), i2c, OFFSET_INTR_MASK);
 
 	spin_lock(&i2c->irqlock);
 	i2c->irq_stat = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
 	i2c->trans_stop = true;
 	spin_unlock(&i2c->irqlock);
-	mtk_i2c_writew(I2C_HS_NACKERR | I2C_ACKERR
+	mtk_i2c_writew(I2C_RS_TRANSFER | I2C_HS_NACKERR | I2C_ACKERR
 			| I2C_TRANSAC_COMP, i2c, OFFSET_INTR_STAT);
 	wake_up(&i2c->wait);
 
@@ -569,6 +600,14 @@  static const struct i2c_adapter_quirks mt6577_i2c_quirks = {
 	.max_comb_2nd_msg_len = MAX_WRRD_TRANS_SIZE_MT6577,
 };
 
+static const struct i2c_adapter_quirks mt8173_i2c_quirks = {
+	.max_num_msgs = MAX_MSG_NUM_MT8173,
+	.max_write_len = MAX_DMA_TRANS_SIZE_MT8173,
+	.max_read_len = MAX_DMA_TRANS_SIZE_MT8173,
+	.max_comb_1st_msg_len = MAX_DMA_TRANS_SIZE_MT8173,
+	.max_comb_2nd_msg_len = MAX_WRRD_TRANS_SIZE_MT8173,
+};
+
 static int mtk_i2c_probe(struct platform_device *pdev)
 {
 	int ret = 0;
@@ -587,7 +626,8 @@  static int mtk_i2c_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	i2c->platform_compat = mtk_get_device_prop(pdev);
-	if (i2c->have_pmic && (i2c->platform_compat & COMPAT_MT6577))
+	if (i2c->have_pmic && (i2c->platform_compat &
+			(COMPAT_MT6577 | COMPAT_MT8173)))
 		return -EINVAL;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -613,7 +653,10 @@  static int mtk_i2c_probe(struct platform_device *pdev)
 	i2c->adap.dev.parent = &pdev->dev;
 	i2c->adap.owner = THIS_MODULE;
 	i2c->adap.algo = &mtk_i2c_algorithm;
-	i2c->adap.quirks = &mt6577_i2c_quirks;
+	if (i2c->platform_compat & COMPAT_MT8173)
+		i2c->adap.quirks = &mt8173_i2c_quirks;
+	else
+		i2c->adap.quirks = &mt6577_i2c_quirks;
 	i2c->adap.timeout = 2 * HZ;
 	i2c->adap.retries = 1;