From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Wed, 30 Jan 2013 17:15:44 +0100 Subject: [U-Boot] [PATCH 06/10] mx23_olinuxino: Add support for status LED In-Reply-To: References: <1359548001-14278-1-git-send-email-otavio@ossystems.com.br> <201301301705.22076.marex@denx.de> Message-ID: <201301301715.44821.marex@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Dear Otavio Salvador, > On Wed, Jan 30, 2013 at 2:05 PM, Marek Vasut wrote: > > Dear Otavio Salvador, > > > >> On Wed, Jan 30, 2013 at 1:39 PM, Marek Vasut wrote: > >> > Dear Otavio Salvador, > >> > > >> >> On Wed, Jan 30, 2013 at 12:13 PM, Marek Vasut wrote: > >> >> > Dear Otavio Salvador, > >> >> > > >> >> >> This allow user to know if the bootloader is running, even without > >> >> >> a serial console. > >> >> >> > >> >> >> Signed-off-by: Otavio Salvador > >> >> > > >> >> > Uh oh, how does this know which GPIO to toggle to drive the led > >> >> > this time ? > >> >> > >> >> The problem wasn't the code but me. I wasn't able to find the right > >> >> GPIO number at that time. > >> > > >> > This is not my question. My question is how does this toggle the GPIO > >> > for the LED? > >> > >> gpio_led driver (drivers/misc/gpio_led.c) does it. > >> > >> ... > >> void __led_init(led_id_t mask, int state) > >> { > >> > >> gpio_request(mask, "gpio_led"); > >> gpio_direction_output(mask, state == STATUS_LED_ON); > >> > >> } > >> > >> void __led_set(led_id_t mask, int state) > >> { > >> > >> gpio_set_value(mask, state == STATUS_LED_ON); > >> > >> } > >> ... > > > > Ok, this didn't explain much to me. > > > >> > Moreover, you never set the LED GPIO as output. > >> > >> The driver handles it by itself. > > > > Oh ok. > > > > Now that I did read through the code, I have few more questions: > > > > Why can't STATUS_LED_BIT be the MX23_PAD_SSP1_DETECT__GPIO_2_1 now? > > It can but than we need to include the iomux-mx23.h header. It in the > end is the same thing. In the end, when I read the code in two hours, I'll be wondering what this magic junk is. Thus, we will go for this and apply the adjustment for iomux. Best regards, Marek Vasut