gpio/tca6424: merge I2C transactions, remove cast

This is a follow-up to ae79c1904 "[PATCH v2] Add support for TCA6424"
merged in the v3.5 merge window.  It fixes comments made when the
patch was merged.
- Use 3 byte transfers instead of two separate transfers (2+1 byte)
- An unnecessary cast removed

Signed-off-by: Andreas Schallenberg <Andreas.Schallenberg@3alitytechnica.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 16 insertions, 12 deletions

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 1c313c710be3..de24af202447 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 +134,27 @@ 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);
-        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 = ret;
         }
-        else
+        else if (chip->gpio_chip.ngpio == 24) {
+                *val = 0;
+                ret = i2c_smbus_read_i2c_block_data(chip->client,
+                                                (reg << 2) | REG_ADDR_AI,
+                                                3,
+                                                (u8 *) val);
+                le32_to_cpus(val);
+        } 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;
 }