* [PATCH] i2c: davinci: Add block read functionality for IPMI
@ 2014-05-01 18:49 Murali Karicheri
2014-05-05 20:30 ` Karicheri, Muralidharan
2014-05-22 10:51 ` Sekhar Nori
0 siblings, 2 replies; 6+ messages in thread
From: Murali Karicheri @ 2014-05-01 18:49 UTC (permalink / raw)
To: davinci-linux-open-source, linux-i2c, linux-kernel
Cc: Murali Karicheri, Garrett Ding, Sekhar Nori, Kevin Hilman,
Wolfram Sang, Santosh Shilimkar
Intelligent Plaform Management Interface (IPMI) requires I2C driver
to support block read, where the first byte received from slave is
the length of following data:-
Added length check if the read type is block read (I2C_M_RECV_LEN)
Send NACK/STOP bits before last byte is received
Signed-off-by: Garrett Ding <g-ding@ti.com>
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Tested-by: Garrett Ding <g-ding@ti.com>
CC: Sekhar Nori <nsekhar@ti.com>
CC: Kevin Hilman <khilman@deeprootsystems.com>
CC: Wolfram Sang <wsa@the-dreams.de>
CC: Santosh Shilimkar <santosh.shilimkar@ti.com>
---
Tested on a customer board based on K2HK SoC
drivers/i2c/busses/i2c-davinci.c | 42 +++++++++++++++++++++++++++++++++-----
1 file changed, 37 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 389bc68..cd97920 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -97,6 +97,10 @@
#define DAVINCI_I2C_IMR_NACK BIT(1)
#define DAVINCI_I2C_IMR_AL BIT(0)
+/* capabilities */
+#define I2C_CAPABILITIES (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | \
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA)
+
struct davinci_i2c_dev {
struct device *dev;
void __iomem *base;
@@ -318,7 +322,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
dev->buf = msg->buf;
- dev->buf_len = msg->len;
+
+ /* if first received byte is length, set buf_len = 0xffff as flag */
+ if (msg->flags & I2C_M_RECV_LEN)
+ dev->buf_len = 0xffff;
+ else
+ dev->buf_len = msg->len;
+
dev->stop = stop;
davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
@@ -456,7 +466,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
static u32 i2c_davinci_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+ return I2C_CAPABILITIES;
}
static void terminate_read(struct davinci_i2c_dev *dev)
@@ -528,10 +538,32 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
case DAVINCI_I2C_IVR_RDR:
if (dev->buf_len) {
- *dev->buf++ =
- davinci_i2c_read_reg(dev,
- DAVINCI_I2C_DRR_REG);
+ *dev->buf++ = davinci_i2c_read_reg(dev,
+ DAVINCI_I2C_DRR_REG);
+ /*
+ * check if the first received byte is message
+ * length, i.e, I2C_M_RECV_LEN
+ */
+ if (dev->buf_len == 0xffff)
+ dev->buf_len = *(dev->buf - 1) + 1;
+
dev->buf_len--;
+ /*
+ * send NACK/STOP bits BEFORE last byte is
+ * received
+ */
+ if (dev->buf_len == 1) {
+ w = davinci_i2c_read_reg(dev,
+ DAVINCI_I2C_MDR_REG);
+ w |= DAVINCI_I2C_MDR_NACK;
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
+
+ w |= DAVINCI_I2C_MDR_STP;
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
+ }
+
if (dev->buf_len)
continue;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* RE: [PATCH] i2c: davinci: Add block read functionality for IPMI
2014-05-01 18:49 [PATCH] i2c: davinci: Add block read functionality for IPMI Murali Karicheri
@ 2014-05-05 20:30 ` Karicheri, Muralidharan
2014-05-22 9:00 ` Wolfram Sang
2014-05-22 10:51 ` Sekhar Nori
1 sibling, 1 reply; 6+ messages in thread
From: Karicheri, Muralidharan @ 2014-05-05 20:30 UTC (permalink / raw)
To: Karicheri, Muralidharan, davinci-linux-open-source, linux-i2c,
linux-kernel
Cc: Ding, Garrett, Nori, Sekhar, Kevin Hilman, Wolfram Sang,
Shilimkar, Santosh
>-----Original Message-----
>From: Karicheri, Muralidharan
>Sent: Thursday, May 01, 2014 2:50 PM
>To: davinci-linux-open-source@linux.davincidsp.com; linux-i2c@vger.kernel.org; linux-
>kernel@vger.kernel.org
>Cc: Karicheri, Muralidharan; Ding, Garrett; Nori, Sekhar; Kevin Hilman; Wolfram Sang;
>Shilimkar, Santosh
>Subject: [PATCH] i2c: davinci: Add block read functionality for IPMI
>
>Intelligent Plaform Management Interface (IPMI) requires I2C driver to support block read,
>where the first byte received from slave is the length of following data:- Added length
>check if the read type is block read (I2C_M_RECV_LEN) Send NACK/STOP bits before last
>byte is received
>
>Signed-off-by: Garrett Ding <g-ding@ti.com>
>Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>Tested-by: Garrett Ding <g-ding@ti.com>
>CC: Sekhar Nori <nsekhar@ti.com>
>CC: Kevin Hilman <khilman@deeprootsystems.com>
>CC: Wolfram Sang <wsa@the-dreams.de>
>CC: Santosh Shilimkar <santosh.shilimkar@ti.com>
>---
> Tested on a customer board based on K2HK SoC
> drivers/i2c/busses/i2c-davinci.c | 42 +++++++++++++++++++++++++++++++++-
>----
> 1 file changed, 37 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
>index 389bc68..cd97920 100644
>--- a/drivers/i2c/busses/i2c-davinci.c
>+++ b/drivers/i2c/busses/i2c-davinci.c
>@@ -97,6 +97,10 @@
> #define DAVINCI_I2C_IMR_NACK BIT(1)
> #define DAVINCI_I2C_IMR_AL BIT(0)
>
>+/* capabilities */
>+#define I2C_CAPABILITIES (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | \
>+ I2C_FUNC_SMBUS_READ_BLOCK_DATA)
>+
> struct davinci_i2c_dev {
> struct device *dev;
> void __iomem *base;
>@@ -318,7 +322,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg
>*msg, int stop)
> davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
>
> dev->buf = msg->buf;
>- dev->buf_len = msg->len;
>+
>+ /* if first received byte is length, set buf_len = 0xffff as flag */
>+ if (msg->flags & I2C_M_RECV_LEN)
>+ dev->buf_len = 0xffff;
>+ else
>+ dev->buf_len = msg->len;
>+
> dev->stop = stop;
>
> davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); @@ -456,7
>+466,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>
> static u32 i2c_davinci_func(struct i2c_adapter *adap) {
>- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>+ return I2C_CAPABILITIES;
> }
>
> static void terminate_read(struct davinci_i2c_dev *dev) @@ -528,10 +538,32 @@ static
>irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
>
> case DAVINCI_I2C_IVR_RDR:
> if (dev->buf_len) {
>- *dev->buf++ =
>- davinci_i2c_read_reg(dev,
>- DAVINCI_I2C_DRR_REG);
>+ *dev->buf++ = davinci_i2c_read_reg(dev,
>+ DAVINCI_I2C_DRR_REG);
>+ /*
>+ * check if the first received byte is message
>+ * length, i.e, I2C_M_RECV_LEN
>+ */
>+ if (dev->buf_len == 0xffff)
>+ dev->buf_len = *(dev->buf - 1) + 1;
>+
> dev->buf_len--;
>+ /*
>+ * send NACK/STOP bits BEFORE last byte is
>+ * received
>+ */
>+ if (dev->buf_len == 1) {
>+ w = davinci_i2c_read_reg(dev,
>+ DAVINCI_I2C_MDR_REG);
>+ w |= DAVINCI_I2C_MDR_NACK;
>+ davinci_i2c_write_reg(dev,
>+ DAVINCI_I2C_MDR_REG, w);
>+
>+ w |= DAVINCI_I2C_MDR_STP;
>+ davinci_i2c_write_reg(dev,
>+ DAVINCI_I2C_MDR_REG, w);
>+ }
>+
> if (dev->buf_len)
> continue;
>
>--
>1.7.9.5
All,
Please review this when you get a chance.
Murali
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: davinci: Add block read functionality for IPMI
2014-05-05 20:30 ` Karicheri, Muralidharan
@ 2014-05-22 9:00 ` Wolfram Sang
2014-06-02 16:28 ` Murali Karicheri
0 siblings, 1 reply; 6+ messages in thread
From: Wolfram Sang @ 2014-05-22 9:00 UTC (permalink / raw)
To: Karicheri, Muralidharan
Cc: davinci-linux-open-source, linux-i2c, linux-kernel, Ding,
Garrett, Nori, Sekhar, Kevin Hilman, Shilimkar, Santosh
[-- Attachment #1: Type: text/plain, Size: 2474 bytes --]
Hi,
thanks for the patch.
> >+/* capabilities */
> >+#define I2C_CAPABILITIES (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | \
> >+ I2C_FUNC_SMBUS_READ_BLOCK_DATA)
I don't see the need for a seperate define.
> >+
> > struct davinci_i2c_dev {
> > struct device *dev;
> > void __iomem *base;
> >@@ -318,7 +322,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg
> >*msg, int stop)
> > davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
> >
> > dev->buf = msg->buf;
> >- dev->buf_len = msg->len;
> >+
> >+ /* if first received byte is length, set buf_len = 0xffff as flag */
> >+ if (msg->flags & I2C_M_RECV_LEN)
> >+ dev->buf_len = 0xffff;
a) this magic value should be a define instead of a comment
b) i2c messages easily have a 16 bit range, so 0xffff is a troublesome
choice.
> >+ else
> >+ dev->buf_len = msg->len;
> >+
> > dev->stop = stop;
> >
> > davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); @@ -456,7
> >+466,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> >
> > static u32 i2c_davinci_func(struct i2c_adapter *adap) {
> >- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> >+ return I2C_CAPABILITIES;
> > }
> >
> > static void terminate_read(struct davinci_i2c_dev *dev) @@ -528,10 +538,32 @@ static
> >irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
> >
> > case DAVINCI_I2C_IVR_RDR:
> > if (dev->buf_len) {
> >- *dev->buf++ =
> >- davinci_i2c_read_reg(dev,
> >- DAVINCI_I2C_DRR_REG);
> >+ *dev->buf++ = davinci_i2c_read_reg(dev,
> >+ DAVINCI_I2C_DRR_REG);
> >+ /*
> >+ * check if the first received byte is message
> >+ * length, i.e, I2C_M_RECV_LEN
> >+ */
> >+ if (dev->buf_len == 0xffff)
> >+ dev->buf_len = *(dev->buf - 1) + 1;
Please rework the code to get rid of the '- 1' and '+ 1'. They look
hackish and make the code less readable.
> >+
> > dev->buf_len--;
> >+ /*
> >+ * send NACK/STOP bits BEFORE last byte is
> >+ * received
> >+ */
> >+ if (dev->buf_len == 1) {
> >+ w = davinci_i2c_read_reg(dev,
> >+ DAVINCI_I2C_MDR_REG);
> >+ w |= DAVINCI_I2C_MDR_NACK;
> >+ davinci_i2c_write_reg(dev,
> >+ DAVINCI_I2C_MDR_REG, w);
> >+
> >+ w |= DAVINCI_I2C_MDR_STP;
> >+ davinci_i2c_write_reg(dev,
> >+ DAVINCI_I2C_MDR_REG, w);
> >+ }
> >+
Looks like an unreleated change to me? Why is this I2C_M_RECV_LEN
specific?
Kind regards,
Wolfram
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: davinci: Add block read functionality for IPMI
2014-05-01 18:49 [PATCH] i2c: davinci: Add block read functionality for IPMI Murali Karicheri
2014-05-05 20:30 ` Karicheri, Muralidharan
@ 2014-05-22 10:51 ` Sekhar Nori
2014-06-02 16:29 ` Murali Karicheri
1 sibling, 1 reply; 6+ messages in thread
From: Sekhar Nori @ 2014-05-22 10:51 UTC (permalink / raw)
To: Murali Karicheri, davinci-linux-open-source, linux-i2c, linux-kernel
Cc: Garrett Ding, Kevin Hilman, Wolfram Sang, Santosh Shilimkar
On Friday 02 May 2014 12:19 AM, Murali Karicheri wrote:
> Intelligent Plaform Management Interface (IPMI) requires I2C driver
> to support block read, where the first byte received from slave is
> the length of following data:-
> Added length check if the read type is block read (I2C_M_RECV_LEN)
> Send NACK/STOP bits before last byte is received
>
> Signed-off-by: Garrett Ding <g-ding@ti.com>
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
I tested this on a DA850 using i2cdetect and it did not seem to break
anything so:
Tested-by: Sekhar Nori <nsekhar@ti.com>
There are some checks that were triggered in checkpatch. You may want
to fix them up.
Thanks,
Sekhar
CHECK: Alignment should match open parenthesis
#112: FILE: drivers/i2c/busses/i2c-davinci.c:557:
+ w = davinci_i2c_read_reg(dev,
+ DAVINCI_I2C_MDR_REG);
CHECK: Alignment should match open parenthesis
#115: FILE: drivers/i2c/busses/i2c-davinci.c:560:
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
CHECK: Alignment should match open parenthesis
#119: FILE: drivers/i2c/busses/i2c-davinci.c:564:
+ davinci_i2c_write_reg(dev,
+ DAVINCI_I2C_MDR_REG, w);
total: 0 errors, 0 warnings, 3 checks, 67 lines checked
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: davinci: Add block read functionality for IPMI
2014-05-22 9:00 ` Wolfram Sang
@ 2014-06-02 16:28 ` Murali Karicheri
0 siblings, 0 replies; 6+ messages in thread
From: Murali Karicheri @ 2014-06-02 16:28 UTC (permalink / raw)
To: Wolfram Sang
Cc: davinci-linux-open-source, linux-i2c, linux-kernel, Ding,
Garrett, Nori, Sekhar, Kevin Hilman, Shilimkar, Santosh
On 5/22/2014 5:00 AM, Wolfram Sang wrote:
> Hi,
>
> thanks for the patch.
>
>>> +/* capabilities */
>>> +#define I2C_CAPABILITIES (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | \
>>> + I2C_FUNC_SMBUS_READ_BLOCK_DATA)
> I don't see the need for a seperate define.
>
>>> +
>>> struct davinci_i2c_dev {
>>> struct device *dev;
>>> void __iomem *base;
>>> @@ -318,7 +322,13 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg
>>> *msg, int stop)
>>> davinci_i2c_write_reg(dev, DAVINCI_I2C_SAR_REG, msg->addr);
>>>
>>> dev->buf = msg->buf;
>>> - dev->buf_len = msg->len;
>>> +
>>> + /* if first received byte is length, set buf_len = 0xffff as flag */
>>> + if (msg->flags & I2C_M_RECV_LEN)
>>> + dev->buf_len = 0xffff;
> a) this magic value should be a define instead of a comment
> b) i2c messages easily have a 16 bit range, so 0xffff is a troublesome
> choice.
>
>>> + else
>>> + dev->buf_len = msg->len;
>>> +
>>> dev->stop = stop;
>>>
>>> davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len); @@ -456,7
>>> +466,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>>>
>>> static u32 i2c_davinci_func(struct i2c_adapter *adap) {
>>> - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>>> + return I2C_CAPABILITIES;
>>> }
>>>
>>> static void terminate_read(struct davinci_i2c_dev *dev) @@ -528,10 +538,32 @@ static
>>> irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
>>>
>>> case DAVINCI_I2C_IVR_RDR:
>>> if (dev->buf_len) {
>>> - *dev->buf++ =
>>> - davinci_i2c_read_reg(dev,
>>> - DAVINCI_I2C_DRR_REG);
>>> + *dev->buf++ = davinci_i2c_read_reg(dev,
>>> + DAVINCI_I2C_DRR_REG);
>>> + /*
>>> + * check if the first received byte is message
>>> + * length, i.e, I2C_M_RECV_LEN
>>> + */
>>> + if (dev->buf_len == 0xffff)
>>> + dev->buf_len = *(dev->buf - 1) + 1;
> Please rework the code to get rid of the '- 1' and '+ 1'. They look
> hackish and make the code less readable.
>
>>> +
>>> dev->buf_len--;
>>> + /*
>>> + * send NACK/STOP bits BEFORE last byte is
>>> + * received
>>> + */
>>> + if (dev->buf_len == 1) {
>>> + w = davinci_i2c_read_reg(dev,
>>> + DAVINCI_I2C_MDR_REG);
>>> + w |= DAVINCI_I2C_MDR_NACK;
>>> + davinci_i2c_write_reg(dev,
>>> + DAVINCI_I2C_MDR_REG, w);
>>> +
>>> + w |= DAVINCI_I2C_MDR_STP;
>>> + davinci_i2c_write_reg(dev,
>>> + DAVINCI_I2C_MDR_REG, w);
>>> + }
>>> +
> Looks like an unreleated change to me? Why is this I2C_M_RECV_LEN
> specific?
>
> Kind regards,
>
> Wolfram
Wolfram,
Thanks for reviewing the patch. I will review your comments and get back
to you. This patch
is tested on a customer board and thus it might be a while before I can
incorporate these changes
and provide an updated patch to the list. Meanwhile I will be reviewing
the comment in the
next few weeks and get back to you in case I have questions.
Thanks and regards,
Murali
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] i2c: davinci: Add block read functionality for IPMI
2014-05-22 10:51 ` Sekhar Nori
@ 2014-06-02 16:29 ` Murali Karicheri
0 siblings, 0 replies; 6+ messages in thread
From: Murali Karicheri @ 2014-06-02 16:29 UTC (permalink / raw)
To: Sekhar Nori
Cc: davinci-linux-open-source, linux-i2c, linux-kernel, Garrett Ding,
Kevin Hilman, Wolfram Sang, Santosh Shilimkar
On 5/22/2014 6:51 AM, Sekhar Nori wrote:
> On Friday 02 May 2014 12:19 AM, Murali Karicheri wrote:
>> Intelligent Plaform Management Interface (IPMI) requires I2C driver
>> to support block read, where the first byte received from slave is
>> the length of following data:-
>> Added length check if the read type is block read (I2C_M_RECV_LEN)
>> Send NACK/STOP bits before last byte is received
>>
>> Signed-off-by: Garrett Ding <g-ding@ti.com>
>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> I tested this on a DA850 using i2cdetect and it did not seem to break
> anything so:
>
> Tested-by: Sekhar Nori <nsekhar@ti.com>
>
> There are some checks that were triggered in checkpatch. You may want
> to fix them up.
>
> Thanks,
> Sekhar
>
> CHECK: Alignment should match open parenthesis
> #112: FILE: drivers/i2c/busses/i2c-davinci.c:557:
> + w = davinci_i2c_read_reg(dev,
> + DAVINCI_I2C_MDR_REG);
>
> CHECK: Alignment should match open parenthesis
> #115: FILE: drivers/i2c/busses/i2c-davinci.c:560:
> + davinci_i2c_write_reg(dev,
> + DAVINCI_I2C_MDR_REG, w);
>
> CHECK: Alignment should match open parenthesis
> #119: FILE: drivers/i2c/busses/i2c-davinci.c:564:
> + davinci_i2c_write_reg(dev,
> + DAVINCI_I2C_MDR_REG, w);
>
> total: 0 errors, 0 warnings, 3 checks, 67 lines checked
>
Sekhar,
Thanks for testing this. I have other comments against this patch and
will be sending an
updated patch in few weeks.
Thanks and regards,
Murali
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-06-02 16:30 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2014-05-01 18:49 [PATCH] i2c: davinci: Add block read functionality for IPMI Murali Karicheri
2014-05-05 20:30 ` Karicheri, Muralidharan
2014-05-22 9:00 ` Wolfram Sang
2014-06-02 16:28 ` Murali Karicheri
2014-05-22 10:51 ` Sekhar Nori
2014-06-02 16:29 ` Murali Karicheri
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