[U-Boot] [PATCH v4 02/24] pmic:i2c: Add I2C sensor byte order (big/little) to PMIC framework

Lukasz Majewski
2012-10-30T16:56:57Z

Since the pmic_reg_read is the u32 value, the order in which bytes
are placed to form u32 value is important.

Support for big and little sensor endianess is added.

Moreover calls to [leXX|beXX]_to_cpu have been added to support
little and big endian SoCs.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Changes for v2:
- Move byte_order variable to struct pmic

Changes for v3:
- New names for sensor endianess (more readable)
- Support for SoCs with different endianess

Changes for v4:
- None
---
drivers/misc/pmic_i2c.c | 38 +++++++++++++++++++++++++++++---------
include/pmic.h | 2 ++
2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/pmic_i2c.c b/drivers/misc/pmic_i2c.c
index e74c372..1064bfe 100644
--- a/drivers/misc/pmic_i2c.c
+++ b/drivers/misc/pmic_i2c.c
@@ -30,6 +30,7 @@
#include <linux/types.h>
#include <pmic.h>
#include <i2c.h>
+#include <compiler.h>

int pmic_reg_write(struct pmic *p, u32 reg, u32 val)
{
@@ -40,16 +41,27 @@ 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 (p->sensor_byte_order == PMIC_SENSOR_BYTE_ORDER_BIG) {
+ buf[2] = (cpu_to_le32(val) >> 16) & 0xff;
+ buf[1] = (cpu_to_le32(val) >> 8) & 0xff;
+ buf[0] = cpu_to_le32(val) & 0xff;
+ } else {
+ buf[0] = (cpu_to_le32(val) >> 16) & 0xff;
+ buf[1] = (cpu_to_le32(val) >> 8) & 0xff;
+ buf[2] = cpu_to_le32(val) & 0xff;
+ }
break;
case 2:
- buf[0] = (val >> 8) & 0xff;
- buf[1] = val & 0xff;
+ if (p->sensor_byte_order == PMIC_SENSOR_BYTE_ORDER_BIG) {
+ buf[1] = (cpu_to_le32(val) >> 8) & 0xff;
+ buf[0] = cpu_to_le32(val) & 0xff;
+ } else {
+ buf[0] = (cpu_to_le32(val) >> 8) & 0xff;
+ buf[1] = cpu_to_le32(val) & 0xff;
+ }
break;
case 1:
- buf[0] = val & 0xff;
+ buf[0] = cpu_to_le32(val) & 0xff;
break;
default:
printf("%s: invalid tx_num: %d", __func__, pmic_i2c_tx_num);
@@ -75,13 +87,21 @@ 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 (p->sensor_byte_order == PMIC_SENSOR_BYTE_ORDER_BIG)
+ ret_val = le32_to_cpu(buf[2] << 16
+ | buf[1] << 8 | buf[0]);
+ else
+ ret_val = le32_to_cpu(buf[0] << 16 |
+ buf[1] << 8 | buf[2]);
break;
case 2:
- ret_val = buf[0] << 8 | buf[1];
+ if (p->sensor_byte_order == PMIC_SENSOR_BYTE_ORDER_BIG)
+ ret_val = le32_to_cpu(buf[1] << 8 | buf[0]);
+ else
+ ret_val = le32_to_cpu(buf[0] << 8 | buf[1]);
break;
case 1:
- ret_val = buf[0];
+ ret_val = le32_to_cpu(buf[0]);
break;
default:
printf("%s: invalid tx_num: %d", __func__, pmic_i2c_tx_num);
diff --git a/include/pmic.h b/include/pmic.h
index 6a05b40..1a2db05 100644
--- a/include/pmic.h
+++ b/include/pmic.h
@@ -27,6 +27,7 @@
enum { PMIC_I2C, PMIC_SPI, };
enum { I2C_PMIC, I2C_NUM, };
enum { PMIC_READ, PMIC_WRITE, };
+enum { PMIC_SENSOR_BYTE_ORDER_LITTLE, PMIC_SENSOR_BYTE_ORDER_BIG, };

struct p_i2c {
unsigned char addr;
@@ -47,6 +48,7 @@ struct pmic {
const char *name;
unsigned char bus;
unsigned char interface;
+ unsigned char sensor_byte_order;
unsigned char number_of_regs;
union hw {
struct p_i2c i2c;
--
1.7.2.3