Re: [U-Boot] [PATCH] board: ge: bx50v3: Use pwm for display backlight

Hi Akshay,

On 06/04/2016 16:39, Akshay Bhat wrote:

On Tue, Mar 15, 2016 at 2:24 PM, Akshay Bhat <akshay.bhat@timesys.com mailto:akshay.bhat@timesys.com> wrote:

Setup the LCD backlight brightness control pin to use PWM

Signed-off-by: Akshay Bhat <akshay.bhat@timesys.com
<mailto:akshay.bhat@timesys.com>>
Cc: Stefano Babic <sbabic@denx.de <mailto:sbabic@denx.de>>
---

Hi Stefano,

Can this be applied if there are no review comments?

This is straightforward and can be applied - but I am afraid you need this just if "Update display setup" is applied.

I have some minor changes to ask for that, I am sending my review.

Best regards, Stefano

Thanks, Akshay

 board/ge/bx50v3/bx50v3.c    | 11 +++++++++++
 include/configs/ge_bx50v3.h |  3 +++
 2 files changed, 14 insertions(+)

diff --git a/board/ge/bx50v3/bx50v3.c b/board/ge/bx50v3/bx50v3.c
index cf2cd1a..8e55acf 100644
--- a/board/ge/bx50v3/bx50v3.c
+++ b/board/ge/bx50v3/bx50v3.c
@@ -25,6 +25,7 @@
 #include <asm/io.h>
 #include <asm/arch/sys_proto.h>
 #include <i2c.h>
+#include <pwm.h>
 DECLARE_GLOBAL_DATA_PTR;

 #define UART_PAD_CTRL  (PAD_CTL_PUS_100K_UP |                  \
@@ -324,6 +325,8 @@ static iomux_v3_cfg_t const backlight_pads[] = {
        /* Backlight enable for LVDS display */
        MX6_PAD_GPIO_0__GPIO1_IO00 | MUX_PAD_CTRL(NO_PAD_CTRL),
 #define LVDS_BACKLIGHT_GP IMX_GPIO_NR(1, 0)
+       /* backlight PWM brightness control */
+       MX6_PAD_SD1_DAT3__PWM1_OUT | MUX_PAD_CTRL(NO_PAD_CTRL),
 };

 static void do_enable_hdmi(struct display_info_t const *dev)
@@ -676,9 +679,17 @@ int board_late_init(void)
         * as per specifications from CHI MEI */
        mdelay(250);

+       /* enable backlight PWM 1 */
+       pwm_init(0, 0, 0);
+
+       /* duty cycle 5000000ns, period: 5000000ns */
+       pwm_config(0, 5000000, 5000000);
+
        /* Backlight Power */
        gpio_direction_output(LVDS_BACKLIGHT_GP, 1);

+       pwm_enable(0);
+
        return 0;
 }

diff --git a/include/configs/ge_bx50v3.h b/include/configs/ge_bx50v3.h
index 6fa4a9a..e37cd33 100644
--- a/include/configs/ge_bx50v3.h
+++ b/include/configs/ge_bx50v3.h
@@ -327,6 +327,9 @@
 #define CONFIG_IMX_HDMI
 #define CONFIG_IMX_VIDEO_SKIP

+#define CONFIG_PWM_IMX
+#define CONFIG_IMX6_PWM_PER_CLK        66000000
+
 #undef CONFIG_CMD_PCI
 #ifdef CONFIG_CMD_PCI
 #define CONFIG_PCI
--
2.7.3