[PATCH] i2c: davinci: Add block read functionality for IPMI

classic Classic list List threaded Threaded
6 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

[PATCH] i2c: davinci: Add block read functionality for IPMI

Murali Karicheri
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 <[hidden email]>
Signed-off-by: Murali Karicheri <[hidden email]>
Tested-by: Garrett Ding <[hidden email]>
CC: Sekhar Nori <[hidden email]>
CC: Kevin Hilman <[hidden email]>
CC: Wolfram Sang <[hidden email]>
CC: Santosh Shilimkar <[hidden email]>
---
 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

_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

RE: [PATCH] i2c: davinci: Add block read functionality for IPMI

Murali Karicheri
>-----Original Message-----
>From: Karicheri, Muralidharan
>Sent: Thursday, May 01, 2014 2:50 PM
>To: [hidden email]; [hidden email]; linux-
>[hidden email]
>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 <[hidden email]>
>Signed-off-by: Murali Karicheri <[hidden email]>
>Tested-by: Garrett Ding <[hidden email]>
>CC: Sekhar Nori <[hidden email]>
>CC: Kevin Hilman <[hidden email]>
>CC: Wolfram Sang <[hidden email]>
>CC: Santosh Shilimkar <[hidden email]>
>---
> 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

_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [PATCH] i2c: davinci: Add block read functionality for IPMI

Wolfram Sang-2
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

_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source

signature.asc (853 bytes) Download Attachment
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [PATCH] i2c: davinci: Add block read functionality for IPMI

Sekhar Nori
In reply to this post by Murali Karicheri
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 <[hidden email]>
> Signed-off-by: Murali Karicheri <[hidden email]>

I tested this on a DA850 using i2cdetect and it did not seem to break
anything so:

Tested-by: Sekhar Nori <[hidden email]>

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

_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [PATCH] i2c: davinci: Add block read functionality for IPMI

Murali Karicheri
In reply to this post by Wolfram Sang-2
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
_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: [PATCH] i2c: davinci: Add block read functionality for IPMI

Murali Karicheri
In reply to this post by Sekhar Nori
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 <[hidden email]>
>> Signed-off-by: Murali Karicheri <[hidden email]>
> I tested this on a DA850 using i2cdetect and it did not seem to break
> anything so:
>
> Tested-by: Sekhar Nori <[hidden email]>
>
> 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
_______________________________________________
Davinci-linux-open-source mailing list
[hidden email]
http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
Loading...