Re: [U-Boot] [PATCH 02/16] pmic:i2c: Add I2C byte order to PMIC framework

17 Sep 2012

Hi Stefano,
...
On 14/09/2012 17:40, Lukasz Majewski wrote:
...
Since the pmic_reg_read is the u32 value, the order in which bytes
are placed to form u32 value is important.
This commit adds the reverse (which is default) and normal byte
order.
Signed-off-by: Lukasz Majewski l.majewski@samsung.com
Signed-off-by: Kyungmin Park kyungmin.park@samsung.com

Hi,
...
drivers/misc/pmic_i2c.c |   31 ++++++++++++++++++++++++-------
 include/pmic.h          |    3 +++
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/pmic_i2c.c b/drivers/misc/pmic_i2c.c
index e74c372..1aa5b7b 100644
--- a/drivers/misc/pmic_i2c.c
+++ b/drivers/misc/pmic_i2c.c
@@ -40,13 +40,24 @@ int pmic_reg_write(struct pmic *p, u32 reg, u32
val) 
   switch (pmic_i2c_tx_num) {
   case 3:

buf[0] = (val >> 16) & 0xff;


buf[1] = (val >> 8) & 0xff;


buf[2] = val & 0xff;




if (pmic_i2c_byte_order == PMIC_BYTE_ORDER_NORMAL)



{

	buf[2] = (val >> 16) & 0xff;


	buf[1] = (val >> 8) & 0xff;


	buf[0] = val & 0xff;


} else {


	buf[0] = (val >> 16) & 0xff;


	buf[1] = (val >> 8) & 0xff;


	buf[2] = val & 0xff;


}

break;
case 2:


buf[0] = (val >> 8) & 0xff;


buf[1] = val & 0xff;




if (pmic_i2c_byte_order == PMIC_BYTE_ORDER_NORMAL)



{

	buf[1] = (val >> 8) & 0xff;


	buf[0] = val & 0xff;


} else {


	buf[0] = (val >> 8) & 0xff;


	buf[1] = val & 0xff;


}

break;
case 1:
buf[0] = val & 0xff;

@@ -75,10 +86,16 @@ int pmic_reg_read(struct pmic *p, u32 reg, u32
*val) 
   switch (pmic_i2c_tx_num) {
   case 3:

ret_val = buf[0] << 16 | buf[1] << 8 | buf[2];




if (pmic_i2c_byte_order == PMIC_BYTE_ORDER_NORMAL)


	ret_val = buf[2] << 16 | buf[1] << 8 |



buf[0];

else


	ret_val = buf[0] << 16 | buf[1] << 8 |



buf[2]; break;
   case 2:

ret_val = buf[0] << 8 | buf[1];




if (pmic_i2c_byte_order == PMIC_BYTE_ORDER_NORMAL)


	ret_val = buf[1] << 8 | buf[0];


else


	ret_val = buf[0] << 8 | buf[1];

break;
case 1:
ret_val = buf[0];

diff --git a/include/pmic.h b/include/pmic.h
index 6a05b40..2166f73 100644
--- a/include/pmic.h
+++ b/include/pmic.h
@@ -27,11 +27,13 @@
 enum { PMIC_I2C, PMIC_SPI, };
 enum { I2C_PMIC, I2C_NUM, };
 enum { PMIC_READ, PMIC_WRITE, };
+enum { PMIC_BYTE_ORDER_REVERSED, PMIC_BYTE_ORDER_NORMAL, };
struct p_i2c {
   unsigned char addr;
   unsigned char *buf;
   unsigned char tx_num;

unsigned char byte_order;

I can imagine we could have the same issue with SPI and not only with
I2C. The byte order is not strictly related to the interface type,
and I think this should add to the "struct pmic" instead of the
"struct p_i2c".
Thanks for reply.
Good point. I will move this to struct pmic.
Best regards,
Lukasz Majewski

    