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SubjectRe: [PATCH 2/3] video: hx8357: Make IM pins optional
Date
On Tuesday, July 16, 2013 12:27 AM, Maxime Ripard wrote:
>
> The IM pins of the HX8357 controller are used to define the interface
> used to feed pixel stream to the LCD panel.
>
> Most of the time, these pins are directly routed to either the ground or
> the VCC to set their values.
>
> Remove the need to assign GPIOs to these pins when we are in such a case.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
> drivers/video/backlight/hx8357.c | 52 +++++++++++++++++++++++-----------------
> 1 file changed, 30 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/video/backlight/hx8357.c b/drivers/video/backlight/hx8357.c
> index a0482b5..ed94796 100644
> --- a/drivers/video/backlight/hx8357.c
> +++ b/drivers/video/backlight/hx8357.c
> @@ -76,6 +76,7 @@ struct hx8357_data {
> unsigned reset;
> struct spi_device *spi;
> int state;
> + bool use_im_pins;
> };
>
> static u8 hx8357_seq_power[] = {
> @@ -250,9 +251,11 @@ static int hx8357_lcd_init(struct lcd_device *lcdev)
> * Set the interface selection pins to SPI mode, with three
> * wires
> */
> - gpio_set_value_cansleep(lcd->im_pins[0], 1);
> - gpio_set_value_cansleep(lcd->im_pins[1], 0);
> - gpio_set_value_cansleep(lcd->im_pins[2], 1);
> + if (lcd->use_im_pins) {
> + gpio_set_value_cansleep(lcd->im_pins[0], 1);
> + gpio_set_value_cansleep(lcd->im_pins[1], 0);
> + gpio_set_value_cansleep(lcd->im_pins[2], 1);
> + }
>
> /* Reset the screen */
> gpio_set_value(lcd->reset, 1);
> @@ -424,26 +427,31 @@ static int hx8357_probe(struct spi_device *spi)
> return -EINVAL;
> }
>
> - for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
> - lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
> - "im-gpios", i);
> - if (lcd->im_pins[i] == -EPROBE_DEFER) {
> - dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
> - return -EPROBE_DEFER;
> - }
> - if (!gpio_is_valid(lcd->im_pins[i])) {
> - dev_err(&spi->dev, "Missing dt property: im-gpios\n");
> - return -EINVAL;
> + if (of_find_property(spi->dev.of_node, "im-gpios", NULL)) {
> + lcd->use_im_pins = 1;
> +
> + for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
> + lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
> + "im-gpios", i);
> + if (lcd->im_pins[i] == -EPROBE_DEFER) {
> + dev_info(&spi->dev, "GPIO requested is not here yet, deferring the
> probe\n");
> + return -EPROBE_DEFER;
> + }
> + if (!gpio_is_valid(lcd->im_pins[i])) {
> + dev_err(&spi->dev, "Missing dt property: im-gpios\n");
> + return -EINVAL;
> + }
> +
> + ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
> + GPIOF_OUT_INIT_LOW, "im_pins");

This makes a checkpatch warning such as 'WARNING: line over 80 characters'.
How about the following?

ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
GPIOF_OUT_INIT_LOW, "im_pins");

> + if (ret) {
> + dev_err(&spi->dev, "failed to request gpio %d: %d\n",
> + lcd->im_pins[i], ret);
> + return -EINVAL;
> + }
> }
> -
> - ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
> - GPIOF_OUT_INIT_LOW, "im_pins");
> - if (ret) {
> - dev_err(&spi->dev, "failed to request gpio %d: %d\n",
> - lcd->im_pins[i], ret);
> - return -EINVAL;
> - }
> - }
> + } else
> + lcd->use_im_pins = 0;

According to the 'Documentation/CodingStyle', braces are necessary as below.

} else {
lcd->use_im_pins = 0;
}


Others look good.
Acked-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

>
> lcdev = lcd_device_register("mxsfb", &spi->dev, lcd, &hx8357_ops);
> if (IS_ERR(lcdev)) {
> --
> 1.8.3.2
>
> --
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