[PATCH V2 3/7] ARM: EXYNOS5: add machine specific support for LCD

Leela Krishna Amudala l.krishna at samsung.com
Thu Jul 19 23:21:48 EST 2012


Hello Marek,

On Wed, Jul 18, 2012 at 12:15 PM, Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
> Hello,
>
> On Wednesday, July 18, 2012 7:57 AM Leela Krishna Amudala wrote:
>
>> This patch adds machine specific support for LCD controller like setting power to LCD
>> and adding LCD platform device.
>>
>> Signed-off-by: Prathyush K <prathyush.k at samsung.com>
>> Signed-off-by: Leela Krishna Amudala <l.krishna at samsung.com>
>> ---
>>  arch/arm/mach-exynos/mach-exynos5-dt.c |   56 ++++++++++++++++++++++++++++++++
>>  1 files changed, 56 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/mach-exynos/mach-exynos5-dt.c b/arch/arm/mach-exynos/mach-exynos5-dt.c
>> index e7113cc..02a0e68 100644
>> --- a/arch/arm/mach-exynos/mach-exynos5-dt.c
>> +++ b/arch/arm/mach-exynos/mach-exynos5-dt.c
>> @@ -13,6 +13,7 @@
>>  #include <linux/serial_core.h>
>>  #include <linux/pwm_backlight.h>
>>  #include <linux/gpio.h>
>> +#include <linux/delay.h>
>>
>>  #include <asm/mach/arch.h>
>>  #include <asm/hardware/gic.h>
>> @@ -24,6 +25,7 @@
>>  #include <plat/gpio-cfg.h>
>>
>>  #include "common.h"
>> +#include <video/platform_lcd.h>
>>
>>  static int smdk5250_bl_notify(struct device *unused, int brightness)
>>  {
>> @@ -47,6 +49,55 @@ static struct platform_pwm_backlight_data smdk5250_bl_data = {
>>       .notify         = smdk5250_bl_notify,
>>  };
>>
>> +static void lcd_set_power(struct plat_lcd_data *pd,
>> +                     unsigned int power)
>> +{
>> +
>> +     /* reset */
>> +     gpio_request_one(EXYNOS5_GPX1(5), GPIOF_OUT_INIT_HIGH, "GPX1");
>> +
>> +     mdelay(20);
>> +     if (power) {
>> +             /* fire nRESET on power up */
>> +             gpio_set_value(EXYNOS5_GPX1(5), 0);
>> +             mdelay(20);
>> +             gpio_set_value(EXYNOS5_GPX1(5), 1);
>> +             mdelay(20);
>> +             gpio_free(EXYNOS5_GPX1(5));
>> +     } else {
>> +             /* fire nRESET on power off */
>> +             gpio_set_value(EXYNOS5_GPX1(5), 0);
>> +             mdelay(20);
>> +             gpio_set_value(EXYNOS5_GPX1(5), 1);
>> +             mdelay(20);
>> +             gpio_free(EXYNOS5_GPX1(5));
>> +     }
>> +     mdelay(20);
>> +
>> +     /*
>> +      * Request lcd_bl_en GPIO for smdk5250_bl_notify().
>> +      * TODO: Fix this so we are not at risk of requesting the GPIO
>> +      * multiple times, this should be done with device tree, and
>> +      * likely integrated into the plat-samsung/dev-backlight.c init.
>> +      */
>> +     gpio_request_one(EXYNOS5_GPX3(0), GPIOF_OUT_INIT_LOW, "GPX3");
>> +}
>> +
>> +static int smdk5250_match_fb(struct plat_lcd_data *pd, struct fb_info *info)
>> +{
>> +     /* Don't call .set_power callback while unblanking */
>> +     return 0;
>> +}
>> +
>> +static struct plat_lcd_data smdk5250_lcd_data = {
>> +     .set_power      = lcd_set_power,
>> +     .match_fb       = smdk5250_match_fb,
>> +};
>> +
>> +static struct platform_device smdk5250_lcd = {
>> +     .name                   = "platform-lcd",
>> +     .dev.platform_data      = &smdk5250_lcd_data,
>> +};
>>  /*
>>   * The following lookup table is used to override device names when devices
>>   * are registered from device tree. This is temporarily added to enable
>> @@ -85,6 +136,10 @@ static const struct of_dev_auxdata exynos5250_auxdata_lookup[] __initconst
>> = {
>>       {},
>>  };
>>
>> +static struct platform_device *smdk5250_devices[] __initdata = {
>> +     &smdk5250_lcd, /* for platform_lcd device */
>> +};
>> +
>>  static void __init exynos5250_dt_map_io(void)
>>  {
>>       exynos_init_io(NULL, 0);
>> @@ -96,6 +151,7 @@ static void __init exynos5250_dt_machine_init(void)
>>       samsung_bl_set(&smdk5250_bl_gpio_info, &smdk5250_bl_data);
>>       of_platform_populate(NULL, of_default_bus_match_table,
>>                               exynos5250_auxdata_lookup, NULL);
>> +     platform_add_devices(smdk5250_devices, ARRAY_SIZE(smdk5250_devices));
>>  }
>>
>>  static char const *exynos5250_dt_compat[] __initdata = {
>
> Sorry, but this patch looks completely weird to me. exynos5-dt machine is aimed to
> operate on ANY Exynos5 based board with proper device tree bindings, not only SMDK5250.
> Please add DT support to platform lcd driver and create required bindings for it
> instead of hardcoding the platform data and gpio numbers in mach-exynos5-dt.c
>

Yes true, that GPIO numbers will vary for boards.
Can you please confirm that platform lcd driver means the core
"drivers/video/backlight/platform_lcd.c" file.
But platform lcd driver is used by other(non samsung) platforms also.
So, If I add the DT suppot to that file, I have to test the changes on
other platforms also.
Can you please kindly suggest me some other way to overcome this situation.

Best Wishes,
Leela Krishna Amudala.

> Best regards
> --
> Marek Szyprowski
> Samsung Poland R&D Center
>
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


More information about the devicetree-discuss mailing list