On Mon, Sep 03, 2012 at 01:03:47PM +0200, Steffen Trumtrar wrote:
> Signed-off-by: Steffen Trumtrar <[email protected]>
> ---
> +static int stmpe_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
> +{
> + struct stmpe_gpio_chip *stmpegpio = container_of(chip, struct
> stmpe_gpio_chip, chip);
> + struct stmpe_client_info *ci = (struct stmpe_client_info
> *)stmpegpio->ci;
> + int ret;
> + u8 val;
> +
> + ci->read_reg(ci->stmpe, GPIO_SET_DIR + OFFSET(gpio), &val);
> + val &= ~(1 << (gpio % 8));
> + ret = ci->write_reg(ci->stmpe, GPIO_SET_DIR + OFFSET(gpio), val);
> +
> + if (ret)
> + dev_err(chip->dev, "couldn't change direction. Write
> failed!\n");
> +
> + return 0;
Please propagate the error value.
> +}
> +
> +static int stmpe_gpio_direction_output(struct gpio_chip *chip, unsigned
> gpio, int value)
> +{
> + struct stmpe_gpio_chip *stmpegpio = container_of(chip, struct
> stmpe_gpio_chip, chip);
> + struct stmpe_client_info *ci = (struct stmpe_client_info
> *)stmpegpio->ci;
> + int ret;
> + u8 val;
> +
> + ci->read_reg(ci->stmpe, GPIO_SET_DIR + OFFSET(gpio), &val);
> + val |= 1 << (gpio % 8);
> + ret = ci->write_reg(ci->stmpe, GPIO_SET_DIR + OFFSET(gpio), val);
> +
> + stmpe_gpio_set_value(chip, gpio, value);
> +
> + if (ret)
> + dev_err(chip->dev, "couldn't change direction. Write
> failed!\n");
> +
> + return 0;
ditto
> +
> +static int stmpe_gpio_probe(struct device_d *dev)
> +{
> + struct stmpe_gpio_chip *stmpegpio;
> + struct stmpe_client_info *ci;
> +
> + stmpegpio = xzalloc(sizeof(*stmpegpio));
> +
> + stmpegpio->base = dev_request_mem_region(dev, 0);
> + stmpegpio->chip.ops = &stmpe_gpio_ops;
> + stmpegpio->ci = dev->platform_data;
> +
> + ci = (struct stmpe_client_info *)stmpegpio->ci;
> +
> + if (ci->stmpe->pdata->gpio_base)
> + stmpegpio->chip.base = ci->stmpe->pdata->gpio_base;
> + else
> + stmpegpio->chip.base = -1;
> +
> + stmpegpio->chip.ngpio = 16;
> + stmpegpio->chip.dev = dev;
> +
> + gpiochip_add(&stmpegpio->chip);
It's worth checking the return value of gpiochip_add. It could indicate
that the selected chip.base is busy.
Sascha
--
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