The multi-byte IO on various pca953x chips requires the auto-increment bit,
while other chips toggle the LSbit automatically. Note that LSbit toggling
only alternates between two registers during the IO, it is not the same as
address auto-increment. The driver currently assumes that #gpios > 16 implies
auto-increment, while #gpios <= 16 implies LSbit toggling. This is incorrect
at there are chips with 16 GPIOs which require the auto-increment bit.
The PCA9575, according to NXP datasheet rev. 4.2 from 16 April 2015, section
7.3 Command Register, the bit 7 in command register is the auto-increment
bit, which allows programming multiple registers sequentially.
Set this bit both in pca953x_gpio_set_multiple(), where it fixes the multi
register programming, and in pca957x_write_regs_16(), where is simplifies
the function. In fact, the pca957x_write_regs_16() now looks rather similar
to pca953x_write_regs_24() and pca953x_write_regs_16(), which is intended
for subsequent patches.
Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
---
V2: No change
V3: No change
---
drivers/gpio/gpio-pca953x.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index ec9fd11cd21c..8f6478f4545f 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -215,13 +215,10 @@ static int pca953x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
static int pca957x_write_regs_16(struct pca953x_chip *chip, int reg, u8 *val)
{
- int ret;
-
- ret = i2c_smbus_write_byte_data(chip->client, reg << 1, val[0]);
- if (ret < 0)
- return ret;
+ u32 regaddr = (reg << 1) | REG_ADDR_AI;
- return i2c_smbus_write_byte_data(chip->client, (reg << 1) + 1, val[1]);
+ return i2c_smbus_write_i2c_block_data(chip->client, regaddr,
+ NBANK(chip), val);
}
static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val)
@@ -408,6 +405,7 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
{
struct pca953x_chip *chip = gpiochip_get_data(gc);
int bank_shift = pca953x_bank_shift(chip);
+ u32 regaddr = chip->regs->output << bank_shift;
unsigned int bank_mask, bank_val;
int bank;
u8 reg_val[MAX_BANK];
@@ -426,8 +424,13 @@ static void pca953x_gpio_set_multiple(struct gpio_chip *gc,
}
}
- ret = i2c_smbus_write_i2c_block_data(chip->client,
- chip->regs->output << bank_shift,
+ /* PCA9575 needs address-increment on multi-byte writes */
+ if ((PCA_CHIP_TYPE(chip->driver_data) == PCA957X_TYPE) &&
+ (NBANK(chip) > 1)) {
+ regaddr |= REG_ADDR_AI;
+ }
+
+ ret = i2c_smbus_write_i2c_block_data(chip->client, regaddr,
NBANK(chip), reg_val);
if (ret)
goto exit;
--
2.18.0
