[PATCH] GPIO/TCA6424: merge I2C transactions, remove cast

From: Andreas Schallenberg
Date: Fri May 18 2012 - 10:20:31 EST


This is a follow-up to "[PATCH v2] Add support for TCA6424":
- Use 3 byte transfers instead of two separate transfers (2+1 byte)
- An unnecessary cast removed

Please check especially if endianness conversion is done the way it should be.

Signed-off-by: Andreas Schallenberg <Andreas.Schallenberg@xxxxxxxxxxxxxxxxxx>

---
drivers/gpio/gpio-pca953x.c | 27 ++++++++++++++++-----------
1 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 1c313c7..5eee524 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -98,12 +98,11 @@ static int pca953x_write_reg(struct pca953x_chip *chip,
int reg, u32 val)
if (chip->gpio_chip.ngpio <= 8)
ret = i2c_smbus_write_byte_data(chip->client, reg, val);
else if (chip->gpio_chip.ngpio == 24) {
- ret = i2c_smbus_write_word_data(chip->client,
+ cpu_to_le32s(&val);
+ ret = i2c_smbus_write_i2c_block_data(chip->client,
(reg << 2) | REG_ADDR_AI,
- val & 0xffff);
- ret = i2c_smbus_write_byte_data(chip->client,
- (reg << 2) + 2,
- (val & 0xff0000) >> 16);
+ 3,
+ (u8 *) &val);
}
else {
switch (chip->chip_type) {
@@ -135,22 +134,28 @@ static int pca953x_read_reg(struct pca953x_chip *chip,
int reg, u32 *val)
{
int ret;

- if (chip->gpio_chip.ngpio <= 8)
+ if (chip->gpio_chip.ngpio <= 8) {
ret = i2c_smbus_read_byte_data(chip->client, reg);
+ *val = ret;
+ }
else if (chip->gpio_chip.ngpio == 24) {
- ret = i2c_smbus_read_word_data(chip->client, reg << 2);
- ret |= (i2c_smbus_read_byte_data(chip->client,
- (reg << 2) + 2)<<16);
+ *val = 0;
+ ret = i2c_smbus_read_i2c_block_data(chip->client,
+ (reg << 2) | REG_ADDR_AI,
+ 3,
+ (u8 *) val);
+ le32_to_cpus(val);
}
- else
+ else {
ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+ *val = ret;
+ }

if (ret < 0) {
dev_err(&chip->client->dev, "failed reading register\n");
return ret;
}

- *val = (u32)ret;
return 0;
}

--
1.7.3.4
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