[U-Boot] [PATCH 09/10] exynos: Enable the LCD backlight for snow

Ajay kumar
2014-03-29T22:35:21Z

Hi Simon,

Find my comments below:

On Wed, Mar 26, 2014 at 11:26 PM, Simon Glass <sjg@chromium.org> wrote:

> The backlight uses FETs on the TPS65090. Enable this so that the display
> is visible.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> board/samsung/smdk5250/exynos5-dt.c | 90
> +++++++++++++++++++++++++++++++++++++
> 1 file changed, 90 insertions(+)
>
> diff --git a/board/samsung/smdk5250/exynos5-dt.c
> b/board/samsung/smdk5250/exynos5-dt.c
> index c83b034..a0ae641 100644
> --- a/board/samsung/smdk5250/exynos5-dt.c
> +++ b/board/samsung/smdk5250/exynos5-dt.c
> @@ -20,6 +20,7 @@
> #include <asm/arch/sromc.h>
> #include <power/pmic.h>
> #include <power/max77686_pmic.h>
> +#include <power/tps65090_pmic.h>
> #include <tmu.h>
>
> DECLARE_GLOBAL_DATA_PTR;
> @@ -60,6 +61,52 @@ int checkboard(void)
> #endif
>
> #ifdef CONFIG_LCD
>
We should make sure this code runs only for snow, and not for SMDK.
Only Snow contains the bridge chip.

> +static int board_dp_bridge_setup(void)
> +{
> + struct exynos5_gpio_part1 *gpio1 =
> + (struct exynos5_gpio_part1 *)samsung_get_base_gpio_part1();
> + const int MAX_TRIES = 10;
> + int num_tries;
> +
> + debug("%s\n", __func__);
> +
> + /* Setup the GPIOs */
> +
> + /* PD is ACTIVE_LOW, and initially de-asserted */
> + s5p_gpio_set_pull(&gpio1->y2, 5, GPIO_PULL_NONE);
> + s5p_gpio_direction_output(&gpio1->y2, 5, 1);
> +
> + /* Reset is ACTIVE_LOW */
> + s5p_gpio_set_pull(&gpio1->x1, 5, GPIO_PULL_NONE);
> + s5p_gpio_direction_output(&gpio1->x1, 5, 0);
> +
> + udelay(10);
> + s5p_gpio_set_value(&gpio1->x1, 5, 1);
> +
> + s5p_gpio_direction_input(&gpio1->x0, 7);
> +
> + /*
> + * We need to wait for 90ms after bringing up the bridge since
> there
> + * is a phantom "high" on the HPD chip during its bootup. The
> phantom
> + * high comes within 7ms of de-asserting PD and persists for at
> least
> + * 15ms. The real high comes roughly 50ms after PD is
> de-asserted. The
> + * phantom high makes it hard for us to know when the NXP chip is
> up.
> + */
> + mdelay(90);
> +
> + for (num_tries = 0; num_tries < MAX_TRIES; num_tries++) {
> + /* Check HPD. If it's high, we're all good. */
> + if (s5p_gpio_get_value(&gpio1->x0, 7))
> + return 0;
> +
> + debug("%s: eDP bridge failed to come up; try %d of %d\n",
> + __func__, num_tries, MAX_TRIES);
> + }
> +
> + /* Immediately go into bridge reset if the hp line is not high */
> + return -ENODEV;
> +}
> +
> void exynos_cfg_lcd_gpio(void)
> {
> struct exynos5_gpio_part1 *gpio1 =
> @@ -81,4 +128,47 @@ void exynos_set_dp_phy(unsigned int onoff)
> {
> set_dp_phy_ctrl(onoff);
> }
> +
> +void exynos_backlight_on(unsigned int onoff)
> +{
> + debug("%s(%u)\n", __func__, onoff);
> +
> + if (onoff) {
> +#ifdef CONFIG_POWER_TPS65090
> + struct exynos5_gpio_part1 *gpio1 =
> + (struct exynos5_gpio_part1 *)
> + samsung_get_base_gpio_part1();
> + int ret;
> +
> + ret = tps65090_fet_enable(1); /* Enable FET1, backlight */
> + if (ret)
> + return;
> +
> + /* T5 in the LCD timing spec (defined as > 10ms) */
> + mdelay(10);
>
Can you check for backlight without using the above delay?

> +
> + /* board_dp_backlight_pwm */
> + s5p_gpio_direction_output(&gpio1->b2, 0, 1);
>
+
> + /* T6 in the LCD timing spec (defined as > 10ms) */
> + mdelay(10);
>
Can you check for backlight without using the above delay?

> +
> + /* board_dp_backlight_en */
> + s5p_gpio_direction_output(&gpio1->x3, 0, 1);
> +#endif
> + }
> +}
> +
> +void exynos_lcd_power_on(void)
> +{
> + debug("%s\n", __func__);
> +
> +#ifdef CONFIG_POWER_TPS65090
> + /* board_dp_lcd_vdd */
> + tps65090_fet_enable(6); /* Enable FET6, lcd panel */
> +#endif
> +
> + board_dp_bridge_setup();
>
returning int. check for return value and print in case of failure.

> +}
> +
> #endif
> --
> 1.9.1.423.g4596e3a
>
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Regards,
Ajay Kumar