[PATCH 0/4] meson i2c driver cleanups

[PATCH 0/4] meson i2c driver cleanups

[Beniamino Galvani]

Some cleanups for the u-boot meson i2c driver.

Beniamino Galvani (4):
  i2c: meson: improve Kconfig description
  i2c: meson: reduce timeout
  i2c: meson: fix return codes on error
  i2c: meson: add some comments

 drivers/i2c/Kconfig     |  7 ++++++-
 drivers/i2c/meson_i2c.c | 31 ++++++++++++++++++++++---------
 2 files changed, 28 insertions(+), 10 deletions(-)

-- 
2.14.3

[PATCH 1/4] i2c: meson: improve Kconfig description

[Beniamino Galvani]

Expand the Kconfig description with hardware features.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
 drivers/i2c/Kconfig | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 1989f8eb57..a7931aa6d4 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -141,7 +141,12 @@ config SYS_I2C_MESON
 	bool "Amlogic Meson I2C driver"
 	depends on DM_I2C && ARCH_MESON
 	help
-	  Add support for the Amlogic Meson I2C driver.
+	  Add support for the I2C controller available in Amlogic Meson
+	  SoCs. The controller supports programmable bus speed including
+	  standard (100kbits/s) and fast (400kbit/s) speed and allows the
+	  software to define a flexible format of the bit streams. It has an
+	  internal buffer holding up to 8 bytes for transfers and supports
+	  both 7-bit and 10-bit addresses.
 
 config SYS_I2C_MXC
 	bool "NXP i.MX I2C driver"
-- 
2.14.3

[PATCH 1/4] i2c: meson: improve Kconfig description

[Simon Glass]

On 26 November 2017 at 09:40, Beniamino Galvani <b.galvani@gmail.com> wrote:
> Expand the Kconfig description with hardware features.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>  drivers/i2c/Kconfig | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
> index 1989f8eb57..a7931aa6d4 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -141,7 +141,12 @@ config SYS_I2C_MESON
>         bool "Amlogic Meson I2C driver"
>         depends on DM_I2C && ARCH_MESON
>         help
> -         Add support for the Amlogic Meson I2C driver.
> +         Add support for the I2C controller available in Amlogic Meson
> +         SoCs. The controller supports programmable bus speed including
> +         standard (100kbits/s) and fast (400kbit/s) speed and allows the
> +         software to define a flexible format of the bit streams. It has an
> +         internal buffer holding up to 8 bytes for transfers and supports
> +         both 7-bit and 10-bit addresses.
>
>  config SYS_I2C_MXC
>         bool "NXP i.MX I2C driver"
> --
> 2.14.3
>

Great!

Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH 1/4] i2c: meson: improve Kconfig description

[Heiko Schocher]

Hello Baniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Expand the Kconfig description with hardware features.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/Kconfig | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)

Thanks!

Reviewed-by: Heiko Schocher <hs@denx.de>

bye,
Heiko
--
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 1/4] i2c: meson: improve Kconfig description

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Expand the Kconfig description with hardware features.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/Kconfig | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)

Applied to u-boot-i2c master

Thanks!

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 2/4] i2c: meson: reduce timeout

[Beniamino Galvani]

The datasheet doesn't specify a suggested timeout and 500ms seems very
long: reduce it to 100ms.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
 drivers/i2c/meson_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/meson_i2c.c b/drivers/i2c/meson_i2c.c
index 2434d9ed53..84e1997c76 100644
--- a/drivers/i2c/meson_i2c.c
+++ b/drivers/i2c/meson_i2c.c
@@ -9,7 +9,7 @@
 #include <dm.h>
 #include <i2c.h>
 
-#define I2C_TIMEOUT_MS		500
+#define I2C_TIMEOUT_MS		100
 
 /* Control register fields */
 #define REG_CTRL_START		BIT(0)
-- 
2.14.3

[PATCH 2/4] i2c: meson: reduce timeout

[Simon Glass]

On 26 November 2017 at 09:40, Beniamino Galvani <b.galvani@gmail.com> wrote:
> The datasheet doesn't specify a suggested timeout and 500ms seems very
> long: reduce it to 100ms.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>  drivers/i2c/meson_i2c.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH 2/4] i2c: meson: reduce timeout

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> The datasheet doesn't specify a suggested timeout and 500ms seems very
> long: reduce it to 100ms.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Thanks!

Reviewed-by: Heiko Schocher <hs@denx.de>

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 2/4] i2c: meson: reduce timeout

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> The datasheet doesn't specify a suggested timeout and 500ms seems very
> long: reduce it to 100ms.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Applied to u-boot-i2c master

Thanks!

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 3/4] i2c: meson: fix return codes on error

[Beniamino Galvani]

Change meson_i2c_xfer_msg() to return -EREMOTEIO in case of NACK, as
done by other drivers. Also, don't change the return error in
meson_i2c_xfer().

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
 drivers/i2c/meson_i2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/meson_i2c.c b/drivers/i2c/meson_i2c.c
index 84e1997c76..2f39214ad2 100644
--- a/drivers/i2c/meson_i2c.c
+++ b/drivers/i2c/meson_i2c.c
@@ -178,7 +178,7 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg,
 
 		if (readl(&i2c->regs->ctrl) & REG_CTRL_ERROR) {
 			debug("meson i2c: error\n");
-			return -ENXIO;
+			return -EREMOTEIO;
 		}
 
 		if ((msg->flags & I2C_M_RD) && i2c->count) {
@@ -200,7 +200,7 @@ static int meson_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 	for (i = 0; i < nmsgs; i++) {
 		ret = meson_i2c_xfer_msg(i2c, msg + i, i == nmsgs - 1);
 		if (ret)
-			return -EREMOTEIO;
+			return ret;
 	}
 
 	return 0;
-- 
2.14.3

[PATCH 3/4] i2c: meson: fix return codes on error

[Simon Glass]

On 26 November 2017 at 09:40, Beniamino Galvani <b.galvani@gmail.com> wrote:
> Change meson_i2c_xfer_msg() to return -EREMOTEIO in case of NACK, as
> done by other drivers. Also, don't change the return error in
> meson_i2c_xfer().
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>  drivers/i2c/meson_i2c.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH 3/4] i2c: meson: fix return codes on error

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Change meson_i2c_xfer_msg() to return -EREMOTEIO in case of NACK, as
> done by other drivers. Also, don't change the return error in
> meson_i2c_xfer().
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Thanks!

Reviewed-by: Heiko Schocher <hs@denx.de>

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 3/4] i2c: meson: fix return codes on error

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Change meson_i2c_xfer_msg() to return -EREMOTEIO in case of NACK, as
> done by other drivers. Also, don't change the return error in
> meson_i2c_xfer().
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Applied to u-boot-i2c master

Thanks!

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 4/4] i2c: meson: add some comments

[Beniamino Galvani]

Add some comment describing the purpose of struct members and
functions.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
 drivers/i2c/meson_i2c.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/meson_i2c.c b/drivers/i2c/meson_i2c.c
index 2f39214ad2..4f37d2f316 100644
--- a/drivers/i2c/meson_i2c.c
+++ b/drivers/i2c/meson_i2c.c
@@ -44,12 +44,12 @@ struct i2c_regs {
 
 struct meson_i2c {
 	struct i2c_regs *regs;
-	struct i2c_msg *msg;
-	bool last;
-	uint count;
-	uint pos;
-	u32 tokens[2];
-	uint num_tokens;
+	struct i2c_msg *msg;	/* Current I2C message */
+	bool last;		/* Whether the message is the last */
+	uint count;		/* Number of bytes in the current transfer */
+	uint pos;		/* Position of current transfer in message */
+	u32 tokens[2];		/* Sequence of tokens to be written */
+	uint num_tokens;	/* Number of tokens to be written */
 };
 
 static void meson_i2c_reset_tokens(struct meson_i2c *i2c)
@@ -69,6 +69,10 @@ static void meson_i2c_add_token(struct meson_i2c *i2c, int token)
 	i2c->num_tokens++;
 }
 
+/*
+ * Retrieve data for the current transfer (which can be at most 8
+ * bytes) from the device internal buffer.
+ */
 static void meson_i2c_get_data(struct meson_i2c *i2c, u8 *buf, int len)
 {
 	u32 rdata0, rdata1;
@@ -86,6 +90,10 @@ static void meson_i2c_get_data(struct meson_i2c *i2c, u8 *buf, int len)
 		*buf++ = (rdata1 >> (i - 4) * 8) & 0xff;
 }
 
+/*
+ * Write data for the current transfer (which can be at most 8 bytes)
+ * to the device internal buffer.
+ */
 static void meson_i2c_put_data(struct meson_i2c *i2c, u8 *buf, int len)
 {
 	u32 wdata0 = 0, wdata1 = 0;
@@ -103,6 +111,11 @@ static void meson_i2c_put_data(struct meson_i2c *i2c, u8 *buf, int len)
 	debug("meson i2c: write data %08x %08x len %d\n", wdata0, wdata1, len);
 }
 
+/*
+ * Prepare the next transfer: pick the next 8 bytes in the remaining
+ * part of message and write tokens and data (if needed) to the
+ * device.
+ */
 static void meson_i2c_prepare_xfer(struct meson_i2c *i2c)
 {
 	bool write = !(i2c->msg->flags & I2C_M_RD);
-- 
2.14.3

[PATCH 4/4] i2c: meson: add some comments

[Simon Glass]

On 26 November 2017 at 09:40, Beniamino Galvani <b.galvani@gmail.com> wrote:
> Add some comment describing the purpose of struct members and
> functions.
>
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>  drivers/i2c/meson_i2c.c | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)

Reviewed-by: Simon Glass <sjg@chromium.org>

[PATCH 4/4] i2c: meson: add some comments

[Heiko Schocher]

Hello Beniammino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Add some comment describing the purpose of struct members and
> functions.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 25 +++++++++++++++++++------
>   1 file changed, 19 insertions(+), 6 deletions(-)

Thanks!

Reviewed-by: Heiko Schocher <hs@denx.de>

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de

[PATCH 4/4] i2c: meson: add some comments

[Heiko Schocher]

Hello Beniamino,

Am 26.11.2017 um 17:40 schrieb Beniamino Galvani:
> Add some comment describing the purpose of struct members and
> functions.
> 
> Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
> ---
>   drivers/i2c/meson_i2c.c | 25 +++++++++++++++++++------
>   1 file changed, 19 insertions(+), 6 deletions(-)

Applied to u-boot-i2c master

Thanks!

bye,
Heiko
-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de