diff options
| author | Marek Vasut <marek.vasut@gmail.com> | 2018-12-12 02:39:51 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2018-12-14 15:18:50 +0100 |
| commit | 8958262af3fb832c9817e50f599c5552957ceaba (patch) | |
| tree | 3bbd935bf833aaacb1224c2c79c3214f13641e00 /drivers/gpio | |
| parent | 92f45ebe68181c2d7f76633ffae55bc9447d62cd (diff) | |
| download | linux-8958262af3fb832c9817e50f599c5552957ceaba.tar.bz2 | |
gpio: pca953x: Repair multi-byte IO address increment on PCA9575
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@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-pca953x.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index 4e9c79ca69c5..479fa376bd18 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; |