[PATCH v2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[PATCH v2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Guenter Roeck]

Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.
Required to support the PMBus zl6100 driver with i2c-mpc.

Reported-by: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Cc: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Signed-off-by: Guenter Roeck <guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org>
---
v2:
  - renamed bool block --> bool recv_len
  - Added I2C_FUNC_SMBUS_BLOCK_PROC_CALL to list of supported features
  - Read data only after updating CCR register

I have not been able to test this patch yet.

 drivers/i2c/busses/i2c-mpc.c |   60 ++++++++++++++++++++++++++++++++----------
 1 files changed, 46 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 107397a..74a2aa5 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
 }
 
 static int mpc_read(struct mpc_i2c *i2c, int target,
-		    u8 *data, int length, int restart)
+		    u8 *data, int length, int restart, bool recv_len)
 {
 	unsigned timeout = i2c->adap.timeout;
 	int i, result;
@@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 		return result;
 
 	if (length) {
-		if (length == 1)
+		if (length == 1 && !recv_len)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		else
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
@@ -479,17 +479,43 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 	}
 
 	for (i = 0; i < length; i++) {
+		u8 byte;
+
 		result = i2c_wait(i2c, timeout, 0);
 		if (result < 0)
 			return result;
 
-		/* Generate txack on next to last byte */
-		if (i == length - 2)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
-		/* Do not generate stop on last byte */
-		if (i == length - 1)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
-		data[i] = readb(i2c->base + MPC_I2C_DR);
+		/*
+		 * For block reads, we have to know the total length (1st byte)
+		 * before we can determine if we are done.
+		 */
+		if (i || !recv_len) {
+			/* Generate txack on next to last byte */
+			if (i == length - 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+			/* Do not generate stop on last byte */
+			if (i == length - 1)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_MTX);
+		}
+
+		byte = readb(i2c->base + MPC_I2C_DR);
+
+		/* Adjust length if first received byte is length */
+		if (i == 0 && recv_len) {
+			if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
+				return -EPROTO;
+			length += byte;
+			/*
+			 * For block reads, generate txack here if data length
+			 * is 1 byte (total length is 2 bytes).
+			 */
+			if (length == 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+		}
+		data[i] = byte;
 	}
 
 	return length;
@@ -532,12 +558,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 			pmsg->flags & I2C_M_RD ? "read" : "write",
 			pmsg->len, pmsg->addr, i + 1, num);
-		if (pmsg->flags & I2C_M_RD)
-			ret =
-			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
-		else
+		if (pmsg->flags & I2C_M_RD) {
+			bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
+
+			ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
+				       recv_len);
+			if (recv_len && ret > 0)
+				pmsg->len = ret;
+		} else {
 			ret =
 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+		}
 	}
 	mpc_i2c_stop(i2c);
 	return (ret < 0) ? ret : num;
@@ -545,7 +576,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 static u32 mpc_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+	  | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 }
 
 static const struct i2c_algorithm mpc_algo = {
-- 
1.7.3.1

[PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Yuantian.Tang-KZfg59tc24xl57MIdRCFDg]

From: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>

Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.

Signed-off-by: Tang Yuantian <Yuantian.Tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---
tested on p1022ds
v2 vs v1:
	-remove signature

 drivers/i2c/busses/i2c-mpc.c |   63 ++++++++++++++++++++++++++++++++---------
 1 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 107397a..bba9a07 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
 }
 
 static int mpc_read(struct mpc_i2c *i2c, int target,
-		    u8 *data, int length, int restart)
+		    u8 *data, int length, int restart, bool recv_len)
 {
 	unsigned timeout = i2c->adap.timeout;
 	int i, result;
@@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 		return result;
 
 	if (length) {
-		if (length == 1)
+		if (length == 1 && !recv_len)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		else
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
@@ -479,17 +479,46 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 	}
 
 	for (i = 0; i < length; i++) {
+		u8 byte;
+
 		result = i2c_wait(i2c, timeout, 0);
 		if (result < 0)
 			return result;
 
-		/* Generate txack on next to last byte */
-		if (i == length - 2)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
-		/* Do not generate stop on last byte */
-		if (i == length - 1)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
-		data[i] = readb(i2c->base + MPC_I2C_DR);
+		/*
+		 * For block reads, we have to know the total length (1st byte)
+		 * before we can determine if we are done.
+		 */
+		if (i || !recv_len) {
+			/* Generate txack on next to last byte */
+			if (i == length - 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+			/* Do not generate stop on last byte */
+			if (i == length - 1)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_MTX);
+		}
+
+		byte = readb(i2c->base + MPC_I2C_DR);
+
+		/*
+		 * Adjust length if first received byte is length.
+		 * The length is 1 length byte plus actually data length
+		 */
+		if (i == 0 && recv_len) {
+			if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
+				return -EPROTO;
+			length += byte;
+			/*
+			 * For block reads, generate txack here if data length
+			 * is 1 byte (total length is 2 bytes).
+			 */
+			if (length == 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+		}
+		data[i] = byte;
 	}
 
 	return length;
@@ -532,12 +561,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 			pmsg->flags & I2C_M_RD ? "read" : "write",
 			pmsg->len, pmsg->addr, i + 1, num);
-		if (pmsg->flags & I2C_M_RD)
-			ret =
-			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
-		else
+		if (pmsg->flags & I2C_M_RD) {
+			bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
+
+			ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
+				       recv_len);
+			if (recv_len && ret > 0)
+				pmsg->len = ret;
+		} else {
 			ret =
 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+		}
 	}
 	mpc_i2c_stop(i2c);
 	return (ret < 0) ? ret : num;
@@ -545,7 +579,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 static u32 mpc_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+	  | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 }
 
 static const struct i2c_algorithm mpc_algo = {
-- 
1.6.4

Re: [PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 276 bytes --]

>    There is not any feedback since 12/12/2011, and this patch has been
>    blocked.

Please resend the patch.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

[PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[b29983-KZfg59tc24xl57MIdRCFDg]

From: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>

Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.

Signed-off-by: Tang Yuantian <Yuantian.Tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
Cc: Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>
Cc: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
Add Cc and resend this patch
tested on p1022ds
v2 vs v1:
	-remove signature

 drivers/i2c/busses/i2c-mpc.c |   63 ++++++++++++++++++++++++++++++++---------
 1 files changed, 49 insertions(+), 14 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 107397a..bba9a07 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -454,7 +454,7 @@ static int mpc_write(struct mpc_i2c *i2c, int target,
 }
 
 static int mpc_read(struct mpc_i2c *i2c, int target,
-		    u8 *data, int length, int restart)
+		    u8 *data, int length, int restart, bool recv_len)
 {
 	unsigned timeout = i2c->adap.timeout;
 	int i, result;
@@ -470,7 +470,7 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 		return result;
 
 	if (length) {
-		if (length == 1)
+		if (length == 1 && !recv_len)
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
 		else
 			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
@@ -479,17 +479,46 @@ static int mpc_read(struct mpc_i2c *i2c, int target,
 	}
 
 	for (i = 0; i < length; i++) {
+		u8 byte;
+
 		result = i2c_wait(i2c, timeout, 0);
 		if (result < 0)
 			return result;
 
-		/* Generate txack on next to last byte */
-		if (i == length - 2)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
-		/* Do not generate stop on last byte */
-		if (i == length - 1)
-			writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX);
-		data[i] = readb(i2c->base + MPC_I2C_DR);
+		/*
+		 * For block reads, we have to know the total length (1st byte)
+		 * before we can determine if we are done.
+		 */
+		if (i || !recv_len) {
+			/* Generate txack on next to last byte */
+			if (i == length - 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+			/* Do not generate stop on last byte */
+			if (i == length - 1)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_MTX);
+		}
+
+		byte = readb(i2c->base + MPC_I2C_DR);
+
+		/*
+		 * Adjust length if first received byte is length.
+		 * The length is 1 length byte plus actually data length
+		 */
+		if (i == 0 && recv_len) {
+			if (byte == 0 || byte > I2C_SMBUS_BLOCK_MAX)
+				return -EPROTO;
+			length += byte;
+			/*
+			 * For block reads, generate txack here if data length
+			 * is 1 byte (total length is 2 bytes).
+			 */
+			if (length == 2)
+				writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA
+					 | CCR_TXAK);
+		}
+		data[i] = byte;
 	}
 
 	return length;
@@ -532,12 +561,17 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			"Doing %s %d bytes to 0x%02x - %d of %d messages\n",
 			pmsg->flags & I2C_M_RD ? "read" : "write",
 			pmsg->len, pmsg->addr, i + 1, num);
-		if (pmsg->flags & I2C_M_RD)
-			ret =
-			    mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
-		else
+		if (pmsg->flags & I2C_M_RD) {
+			bool recv_len = pmsg->flags & I2C_M_RECV_LEN;
+
+			ret = mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i,
+				       recv_len);
+			if (recv_len && ret > 0)
+				pmsg->len = ret;
+		} else {
 			ret =
 			    mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+		}
 	}
 	mpc_i2c_stop(i2c);
 	return (ret < 0) ? ret : num;
@@ -545,7 +579,8 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 static u32 mpc_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+	  | I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL;
 }
 
 static const struct i2c_algorithm mpc_algo = {
-- 
1.6.4

RE: [PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Huang Changming-R66093]

Hi, Wolfram,
My workmate (Tang Yuantian) has re-post it, please review.

Thanks
Jerry Huang


> -----Original Message-----
> From: Wolfram Sang [mailto:w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org]
> Sent: Thursday, February 23, 2012 5:16 PM
> To: Huang Changming-R66093
> Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org;
> guenter.roeck-IzeFyvvaP7pWk0Htik3J/w@public.gmane.org; Tang Yuantian-B29983; sun york-R58495
> Subject: Re: [PATCH][V2] i2c/busses: (mpc) Add support for
> SMBUS_READ_BLOCK_DATA
> 
> >    There is not any feedback since 12/12/2011, and this patch has been
> >    blocked.
> 
> Please resend the patch.
> 
> --
> Pengutronix e.K.                           | Wolfram Sang
> |
> Industrial Linux Solutions                 | http://www.pengutronix.de/
> |

Re: [PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 511 bytes --]

On Thu, Feb 23, 2012 at 05:42:45PM +0800, b29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org wrote:
> From: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> 
> Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.
> 
> Signed-off-by: Tang Yuantian <Yuantian.Tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>

Thanks, picked.

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

RE: [PATCH][V2] i2c/busses: (mpc) Add support for SMBUS_READ_BLOCK_DATA

[Huang Changming-R66093]

Thanks, Wlofram.

Thanks
Jerry Huang


> -----Original Message-----
> From: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-i2c-
> owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Wolfram Sang
> Sent: Friday, February 24, 2012 7:22 PM
> To: Tang Yuantian-B29983
> Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Tang Yuantian-B29983; Ben Dooks
> Subject: Re: [PATCH][V2] i2c/busses: (mpc) Add support for
> SMBUS_READ_BLOCK_DATA
> 
> On Thu, Feb 23, 2012 at 05:42:45PM +0800, b29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org wrote:
> > From: Tang Yuantian <B29983-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> >
> > Add support for SMBUS_READ_BLOCK_DATA to the i2c-mpc bus driver.
> >
> > Signed-off-by: Tang Yuantian <Yuantian.Tang-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> 
> Thanks, picked.
> 
> --
> Pengutronix e.K.                           | Wolfram Sang
> |
> Industrial Linux Solutions                 | http://www.pengutronix.de/
> |