Messages in this thread | | | From | Andy Shevchenko <> | Date | Fri, 29 Dec 2017 11:44:47 +0200 | Subject | Re: [PATCH] gpio-pca953x: fall back to byte-at-a-time for 24-bit io |
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On Tue, Dec 5, 2017 at 4:17 AM, Andrew Cooks <andrew.cooks@opengear.com> wrote: > Using TCA6424A with i2c-piix4 bus driver requires byte-at-a-time IO, > because the i2c-piix4 driver (and probably some SMBus controllers) don't > support I2C_SMBUS_I2C_BLOCK_DATA.
Why not to fix piix4 for now?
> static int pca953x_write_regs_24(struct pca953x_chip *chip, int reg, u8 *val) > { > + int ret, i; > int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ); > > - return i2c_smbus_write_i2c_block_data(chip->client, > + if (i2c_check_functionality(chip->client->adapter, > + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { > + return i2c_smbus_write_i2c_block_data(chip->client, > (reg << bank_shift) | REG_ADDR_AI, > NBANK(chip), val);
> + } else {
Redundant and makes useless indentation level below.
> + for (i = 0; i < NBANK(chip); i++) { > + ret = i2c_smbus_write_byte_data(chip->client, > + (reg << 1) + i, val[i]); > + if (ret < 0) > + return ret; > + } > + return ret; > + } > } > > static int pca953x_write_regs(struct pca953x_chip *chip, int reg, u8 *val) > @@ -249,7 +261,7 @@ static int pca953x_read_regs_24(struct pca953x_chip *chip, int reg, u8 *val) > { > int bank_shift = fls((chip->gpio_chip.ngpio - 1) / BANK_SZ); > > - return i2c_smbus_read_i2c_block_data(chip->client, > + return i2c_smbus_read_i2c_block_data_or_emulated(chip->client, > (reg << bank_shift) | REG_ADDR_AI, > NBANK(chip), val);
Don't we have a counter part for writing?
Perhaps, it might be another option.
-- With Best Regards, Andy Shevchenko
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