[U-Boot] [PATCH v4 0/6] I2C fixes for the R-Car H3

[U-Boot] [PATCH v4 0/6] I2C fixes for the R-Car H3

[Ismael Luceno Cortes]

This series is meant to be applied on top of the "i2c: rcar_i2c: Add
Gen3 SoC support" patch.


Ismael Luceno (6):
  i2c: rcar_i2c: Setup SCL/SDA delay at rcar_i2c_set_speed
  i2c: rcar_i2c: Add comments about registers & values
  i2c: rcar_i2c: Fix sending of slave addresses
  i2c: rcar_i2c: Don't mask errors with EREMOTEIO at rcar_i2c_xfer
  i2c: rcar_i2c: Set the slave address from rcar_i2c_xfer
  i2c: rcar_i2c: Move FSDA check to rcar_i2c_recover

 drivers/i2c/rcar_i2c.c | 87 +++++++++++++++++++++++-------------------
 1 file changed, 47 insertions(+), 40 deletions(-)


base-commit: f08023c07d826fbc8e62fdd3367961b2f0b06844
prerequisite-patch-id: 9e5b0458bc15640eb483ccad91dbe85150f9f7be
-- 
2.19.1

[U-Boot] [PATCH v4 1/6] i2c: rcar_i2c: Setup SCL/SDA delay at rcar_i2c_set_speed

[Ismael Luceno Cortes]

Setting up the delay only needs to be done once; move it to
rcar_i2c_set_speed so it's done at initialization time.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
---

Notes:
    Changes since v3:
    - Removed unused variable val @ rcar_i2c_set_addr
    
    Changes since v2:
    - Improved commit message
    - Style fixes

 drivers/i2c/rcar_i2c.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index 10b0f8bad4..32176d3b45 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -108,7 +108,6 @@ static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read)
 	struct rcar_i2c_priv *priv = dev_get_priv(dev);
 	u32 mask = RCAR_I2C_ICMSR_MAT |
 		   (read ? RCAR_I2C_ICMSR_MDR : RCAR_I2C_ICMSR_MDE);
-	u32 val;
 	int ret;
 
 	writel(0, priv->base + RCAR_I2C_ICMIER);
@@ -116,9 +115,7 @@ static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read)
 	writel(0, priv->base + RCAR_I2C_ICMSR);
 	writel(priv->icccr, priv->base + RCAR_I2C_ICCCR);
 
-	if (priv->type == RCAR_I2C_TYPE_GEN3)
-		writel(RCAR_I2C_ICFBSCR_TCYC17, priv->base + RCAR_I2C_ICFBSCR);
-
+	/* Wait for the bus */
 	ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMCR,
 				RCAR_I2C_ICMCR_FSDA, false, 2, true);
 	if (ret) {
@@ -304,6 +301,11 @@ scgd_find:
 	priv->icccr = (scgd << RCAR_I2C_ICCCR_SCGD_OFF) | cdf;
 	writel(priv->icccr, priv->base + RCAR_I2C_ICCCR);
 
+	if (priv->type == RCAR_I2C_TYPE_GEN3) {
+		/* Set SCL/SDA delay */
+		writel(RCAR_I2C_ICFBSCR_TCYC17, priv->base + RCAR_I2C_ICFBSCR);
+	}
+
 	return 0;
 }
 
-- 
2.19.1

[U-Boot] [PATCH v4 2/6] i2c: rcar_i2c: Add comments about registers & values

[Ismael Luceno Cortes]

Document the meaning of macros related to registers and values to be
written to them.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
---

Notes:
    Changes since v2:
    - Fixed style of comments
    
    Changes since v1:
    - Rebased on top of patch 1050650 ("i2c: rcar_i2c: Add Gen3 SoC support")

 drivers/i2c/rcar_i2c.c | 47 +++++++++++++++++++++++-------------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index 32176d3b45..eb64115c51 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -18,35 +18,40 @@
 #include <asm/io.h>
 #include <wait_bit.h>
 
-#define RCAR_I2C_ICSCR			0x00
-#define RCAR_I2C_ICMCR			0x04
-#define RCAR_I2C_ICMCR_MDBS		BIT(7)
-#define RCAR_I2C_ICMCR_FSCL		BIT(6)
-#define RCAR_I2C_ICMCR_FSDA		BIT(5)
-#define RCAR_I2C_ICMCR_OBPC		BIT(4)
-#define RCAR_I2C_ICMCR_MIE		BIT(3)
+#define RCAR_I2C_ICSCR			0x00 /* slave ctrl */
+#define RCAR_I2C_ICMCR			0x04 /* master ctrl */
+#define RCAR_I2C_ICMCR_MDBS		BIT(7) /* non-fifo mode switch */
+#define RCAR_I2C_ICMCR_FSCL		BIT(6) /* override SCL pin */
+#define RCAR_I2C_ICMCR_FSDA		BIT(5) /* override SDA pin */
+#define RCAR_I2C_ICMCR_OBPC		BIT(4) /* override pins */
+#define RCAR_I2C_ICMCR_MIE		BIT(3) /* master if enable */
 #define RCAR_I2C_ICMCR_TSBE		BIT(2)
-#define RCAR_I2C_ICMCR_FSB		BIT(1)
-#define RCAR_I2C_ICMCR_ESG		BIT(0)
-#define RCAR_I2C_ICSSR			0x08
-#define RCAR_I2C_ICMSR			0x0c
+#define RCAR_I2C_ICMCR_FSB		BIT(1) /* force stop bit */
+#define RCAR_I2C_ICMCR_ESG		BIT(0) /* enable start bit gen */
+#define RCAR_I2C_ICSSR			0x08 /* slave status */
+#define RCAR_I2C_ICMSR			0x0c /* master status */
 #define RCAR_I2C_ICMSR_MASK		0x7f
-#define RCAR_I2C_ICMSR_MNR		BIT(6)
-#define RCAR_I2C_ICMSR_MAL		BIT(5)
-#define RCAR_I2C_ICMSR_MST		BIT(4)
+#define RCAR_I2C_ICMSR_MNR		BIT(6) /* Nack */
+#define RCAR_I2C_ICMSR_MAL		BIT(5) /* Arbitration lost */
+#define RCAR_I2C_ICMSR_MST		BIT(4) /* Stop */
 #define RCAR_I2C_ICMSR_MDE		BIT(3)
 #define RCAR_I2C_ICMSR_MDT		BIT(2)
 #define RCAR_I2C_ICMSR_MDR		BIT(1)
 #define RCAR_I2C_ICMSR_MAT		BIT(0)
-#define RCAR_I2C_ICSIER			0x10
-#define RCAR_I2C_ICMIER			0x14
-#define RCAR_I2C_ICCCR			0x18
+#define RCAR_I2C_ICSIER			0x10 /* slave irq enable */
+#define RCAR_I2C_ICMIER			0x14 /* master irq enable */
+#define RCAR_I2C_ICCCR			0x18 /* clock dividers */
 #define RCAR_I2C_ICCCR_SCGD_OFF		3
-#define RCAR_I2C_ICSAR			0x1c
-#define RCAR_I2C_ICMAR			0x20
-#define RCAR_I2C_ICRXD_ICTXD		0x24
+#define RCAR_I2C_ICSAR			0x1c /* slave address */
+#define RCAR_I2C_ICMAR			0x20 /* master address */
+#define RCAR_I2C_ICRXD_ICTXD		0x24 /* data port */
+/*
+ * First Bit Setup Cycle (Gen3).
+ * Defines 1st bit delay between SDA and SCL.
+ */
 #define RCAR_I2C_ICFBSCR		0x38
-#define RCAR_I2C_ICFBSCR_TCYC17		0x0f
+#define RCAR_I2C_ICFBSCR_TCYC17		0x0f /* 17*Tcyc */
+
 
 enum rcar_i2c_type {
 	RCAR_I2C_TYPE_GEN2,
-- 
2.19.1

[U-Boot] [PATCH v4 3/6] i2c: rcar_i2c: Fix sending of slave addresses

[Ismael Luceno Cortes]

Do the reset before clearing the MSR, otherwise it may result in a read
or write operation instead if the start condition is repeated.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@gmail.com>
---

Notes:
    Changes since v1:
    - Rebased on top of patch 1050650 ("i2c: rcar_i2c: Add Gen3 SoC support")

 drivers/i2c/rcar_i2c.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index eb64115c51..a2c62cf934 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -133,9 +133,11 @@ static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read)
 	}
 
 	writel((chip << 1) | read, priv->base + RCAR_I2C_ICMAR);
-	writel(0, priv->base + RCAR_I2C_ICMSR);
+	/* Reset */
 	writel(RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE | RCAR_I2C_ICMCR_ESG,
 	       priv->base + RCAR_I2C_ICMCR);
+	/* Clear Status */
+	writel(0, priv->base + RCAR_I2C_ICMSR);
 
 	ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMSR, mask,
 				true, 100, true);
-- 
2.19.1

[U-Boot] [PATCH v4 4/6] i2c: rcar_i2c: Don't mask errors with EREMOTEIO at rcar_i2c_xfer

[Ismael Luceno Cortes]

Fix rcar_i2c_xfer return value, previously it was always returning
-EREMOTEIO when dealing with errors from calls to the read/write
functions.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
---

Notes:
    Changes since v2:
    - Fixed commit message
    
    Changes since v1:
    - Rebased on top of patch 1050650 ("i2c: rcar_i2c: Add Gen3 SoC support")

 drivers/i2c/rcar_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index a2c62cf934..eb2158ae00 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -220,7 +220,7 @@ static int rcar_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
 			ret = rcar_i2c_write_common(dev, msg);
 
 		if (ret)
-			return -EREMOTEIO;
+			return ret;
 	}
 
 	return ret;
-- 
2.19.1

[U-Boot] [PATCH v4 5/6] i2c: rcar_i2c: Set the slave address from rcar_i2c_xfer

[Ismael Luceno Cortes]

It needs to be done for both reads and writes, so do it at rcar_i2c_xfer
to avoid duplication.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
---

Notes:
    Changes since v2:
    - Fixed commit message
    
    Changes since v1:
    - Rebased on top of patch 1050650 ("i2c: rcar_i2c: Add Gen3 SoC support")
    - Fixed masking of return value from rcar_i2c_set_addr

 drivers/i2c/rcar_i2c.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index eb2158ae00..999724e964 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -157,10 +157,6 @@ static int rcar_i2c_read_common(struct udevice *dev, struct i2c_msg *msg)
 	u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE;
 	int i, ret = -EREMOTEIO;
 
-	ret = rcar_i2c_set_addr(dev, msg->addr, 1);
-	if (ret)
-		return ret;
-
 	for (i = 0; i < msg->len; i++) {
 		if (msg->len - 1 == i)
 			icmcr |= RCAR_I2C_ICMCR_FSB;
@@ -187,10 +183,6 @@ static int rcar_i2c_write_common(struct udevice *dev, struct i2c_msg *msg)
 	u32 icmcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_MIE;
 	int i, ret = -EREMOTEIO;
 
-	ret = rcar_i2c_set_addr(dev, msg->addr, 0);
-	if (ret)
-		return ret;
-
 	for (i = 0; i < msg->len; i++) {
 		writel(msg->buf[i], priv->base + RCAR_I2C_ICRXD_ICTXD);
 		writel(icmcr, priv->base + RCAR_I2C_ICMCR);
@@ -214,6 +206,10 @@ static int rcar_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
 	int ret;
 
 	for (; nmsgs > 0; nmsgs--, msg++) {
+		ret = rcar_i2c_set_addr(dev, msg->addr, 1);
+		if (ret)
+			return ret;
+
 		if (msg->flags & I2C_M_RD)
 			ret = rcar_i2c_read_common(dev, msg);
 		else
@@ -223,7 +219,7 @@ static int rcar_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
 			return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static int rcar_i2c_probe_chip(struct udevice *dev, uint addr, uint flags)
-- 
2.19.1

[U-Boot] [PATCH v4 6/6] i2c: rcar_i2c: Move FSDA check to rcar_i2c_recover

[Ismael Luceno Cortes]

Cosmetic change.  Any call to the recover function would need to do the
same check afterwards, so it's sensible to make it part of the function.

Signed-off-by: Ismael Luceno <ismael.luceno@silicon-gears.com>
---

Notes:
    Changes since v2:
    - Fixed variable names
    - Fixed return value to be standard
    
    Changes since v1:
    - Rebased on top of patch 1050650 ("i2c: rcar_i2c: Add Gen3 SoC support")
    - Explained the change
    - Replaced C99-style variable declaration

 drivers/i2c/rcar_i2c.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/rcar_i2c.c b/drivers/i2c/rcar_i2c.c
index 999724e964..2ebae349ed 100644
--- a/drivers/i2c/rcar_i2c.c
+++ b/drivers/i2c/rcar_i2c.c
@@ -81,12 +81,13 @@ static int rcar_i2c_finish(struct udevice *dev)
 	return ret;
 }
 
-static void rcar_i2c_recover(struct udevice *dev)
+static int rcar_i2c_recover(struct udevice *dev)
 {
 	struct rcar_i2c_priv *priv = dev_get_priv(dev);
 	u32 mcr = RCAR_I2C_ICMCR_MDBS | RCAR_I2C_ICMCR_OBPC;
 	u32 mcra = mcr | RCAR_I2C_ICMCR_FSDA;
 	int i;
+	u32 mstat;
 
 	/* Send 9 SCL pulses */
 	for (i = 0; i < 9; i++) {
@@ -106,6 +107,9 @@ static void rcar_i2c_recover(struct udevice *dev)
 	udelay(5);
 	writel(mcra | RCAR_I2C_ICMCR_FSCL, priv->base + RCAR_I2C_ICMCR);
 	udelay(5);
+
+	mstat = readl(priv->base + RCAR_I2C_ICMSR);
+	return mstat & RCAR_I2C_ICMCR_FSDA ? -EBUSY : 0;
 }
 
 static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read)
@@ -124,9 +128,7 @@ static int rcar_i2c_set_addr(struct udevice *dev, u8 chip, u8 read)
 	ret = wait_for_bit_le32(priv->base + RCAR_I2C_ICMCR,
 				RCAR_I2C_ICMCR_FSDA, false, 2, true);
 	if (ret) {
-		rcar_i2c_recover(dev);
-		val = readl(priv->base + RCAR_I2C_ICMSR);
-		if (val & RCAR_I2C_ICMCR_FSDA) {
+		if (rcar_i2c_recover(dev)) {
 			dev_err(dev, "Bus busy, aborting\n");
 			return ret;
 		}
-- 
2.19.1

[U-Boot] [PATCH v4 0/6] I2C fixes for the R-Car H3

[Marek Vasut]

On 3/7/19 2:34 PM, Ismael Luceno Cortes wrote:
> This series is meant to be applied on top of the "i2c: rcar_i2c: Add
> Gen3 SoC support" patch.
> 
> 
> Ismael Luceno (6):
>   i2c: rcar_i2c: Setup SCL/SDA delay at rcar_i2c_set_speed
>   i2c: rcar_i2c: Add comments about registers & values
>   i2c: rcar_i2c: Fix sending of slave addresses
>   i2c: rcar_i2c: Don't mask errors with EREMOTEIO at rcar_i2c_xfer
>   i2c: rcar_i2c: Set the slave address from rcar_i2c_xfer
>   i2c: rcar_i2c: Move FSDA check to rcar_i2c_recover
> 
>  drivers/i2c/rcar_i2c.c | 87 +++++++++++++++++++++++-------------------
>  1 file changed, 47 insertions(+), 40 deletions(-)
> 
> 
> base-commit: f08023c07d826fbc8e62fdd3367961b2f0b06844
> prerequisite-patch-id: 9e5b0458bc15640eb483ccad91dbe85150f9f7be
> 
Nit: You want to keep my R-B tags on patches that didn't change :)

-- 
Best regards,
Marek Vasut

[U-Boot] [PATCH v4 0/6] I2C fixes for the R-Car H3

[Ismael Luceno Cortes]

Please ignore this series; I made a mistake, I'll submit a v5.

On 07/Mar/2019 13:34, Ismael Luceno Cortes wrote:
> This series is meant to be applied on top of the "i2c: rcar_i2c: Add
> Gen3 SoC support" patch.
> 
> 
> Ismael Luceno (6):
>   i2c: rcar_i2c: Setup SCL/SDA delay at rcar_i2c_set_speed
>   i2c: rcar_i2c: Add comments about registers & values
>   i2c: rcar_i2c: Fix sending of slave addresses
>   i2c: rcar_i2c: Don't mask errors with EREMOTEIO at rcar_i2c_xfer
>   i2c: rcar_i2c: Set the slave address from rcar_i2c_xfer
>   i2c: rcar_i2c: Move FSDA check to rcar_i2c_recover
> 
>  drivers/i2c/rcar_i2c.c | 87 +++++++++++++++++++++++-------------------
>  1 file changed, 47 insertions(+), 40 deletions(-)
> 
> 
> base-commit: f08023c07d826fbc8e62fdd3367961b2f0b06844
> prerequisite-patch-id: 9e5b0458bc15640eb483ccad91dbe85150f9f7be
> -- 
> 2.19.1