Re: [PATCH 05/33] arm: omap: board-cm-t35: use generic dpi panel's gpio handling

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

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On 2013-02-14 15:51, Igor Grinberg wrote:
> On 02/14/13 14:52, Tomi Valkeinen wrote:
>> On 2013-02-14 14:37, Igor Grinberg wrote:
>>> On 02/14/13 12:59, Tomi Valkeinen wrote:
>>>> On 2013-02-14 11:43, Igor Grinberg wrote:
>>>
>>>>>> True, it's generic, but does it work reliably? The panel hardware is now
>>>>>> partly handled in the backlight driver, and partly in the omap's panel
>>>>>> driver (and wherever on other platforms).
>>>>>
>>>>> It works reliably on other platforms, but not on OMAP - because
>>>>> we need to cope with the OMAP specific framework...
>>>
>>>> How do you handle the gpios on other platform? Those are the ones
>>>> causing the issues here, right?
>>>
>>> Well, I'm also talking about something that is a history already.
>>> Remember, we had multiple panel drivers inside the
>>> video/omap2/displays and then they were consolidated into the
>>> "generic dpi/dsi/whatever".
> 
>> Sorry, I miss the point. Was that a bad thing? Didn't it simplify the
>> task for you with simple panels? It could've been taken even further,
>> though (see below).
> 
> Yes it was a good thing (I have already told this below).
> 
> 
>>> And yes you are right, on the platforms I'm aware of, the GPIO is not
>>> handled. Apparently its hardware default (pull resistor) is always on...
> 
>> Ok, so the simple fix of setting the GPIOs only in the board file is
>> acceptable for now.
> 
> Yep. I also told this already in one of the previous emails.
> 
> 
>> Can the LCD_BL_GPIO be handled by the omap panel driver? Otherwise the
>> backlight will supposedly be always on. Is it just a simple switch for
>> the BL power, which does not affect the SPI in any way?
> 
> Yes, it can for now.
> Also, I think we should also take into account the backlight framework,
> including PMW.

I've updated this patch to set the LCD EN gpio once at boot time, and pass the
LCD BL gpio to the panel driver. Updated patch below.

---

commit a58a72363aa4359cdb75878de1517bd50faf9eb4
Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
Date:   Mon Dec 3 16:05:06 2012 +0530

    arm: omap: board-cm-t35: use generic dpi panel's gpio handling
    
    The cm-t35 board file currently requests gpios required to configure the tdo35s
    panel, and provides platform_enable/disable callbacks to configure them.
    
    These tasks have been moved to the generic dpi panel driver itself and shouldn't
    be done in the board files.
    
    Remove the gpio requests and the platform callbacks from the board file.
    Add the gpio information to generic dpi panel's platform data so that it's
    passed to the panel driver.
    
    Note: Only BL enable gpio is handled in the panel driver. The LCD enable
    GPIO is handled in the board file at init time, as there's a 50 ms delay
    required when using the GPIO, and the panel driver doesn't know about
    that.
    
    Cc: Tony Lindgren <tony@atomide.com>
    Cc: Igor Grinberg <grinberg@compulab.co.il>
    Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --git a/arch/arm/mach-omap2/board-cm-t35.c b/arch/arm/mach-omap2/board-cm-t35.c
index bccd3e5..cccbfea 100644
--- a/arch/arm/mach-omap2/board-cm-t35.c
+++ b/arch/arm/mach-omap2/board-cm-t35.c
@@ -190,32 +190,6 @@ static inline void cm_t35_init_nand(void) {}
 #define CM_T35_LCD_BL_GPIO 58
 #define CM_T35_DVI_EN_GPIO 54
 
-static int lcd_enabled;
-static int dvi_enabled;
-
-static int cm_t35_panel_enable_lcd(struct omap_dss_device *dssdev)
-{
-	if (dvi_enabled) {
-		printk(KERN_ERR "cannot enable LCD, DVI is enabled\n");
-		return -EINVAL;
-	}
-
-	gpio_set_value(CM_T35_LCD_EN_GPIO, 1);
-	gpio_set_value(CM_T35_LCD_BL_GPIO, 1);
-
-	lcd_enabled = 1;
-
-	return 0;
-}
-
-static void cm_t35_panel_disable_lcd(struct omap_dss_device *dssdev)
-{
-	lcd_enabled = 0;
-
-	gpio_set_value(CM_T35_LCD_BL_GPIO, 0);
-	gpio_set_value(CM_T35_LCD_EN_GPIO, 0);
-}
-
 static int cm_t35_panel_enable_tv(struct omap_dss_device *dssdev)
 {
 	return 0;
@@ -227,8 +201,10 @@ static void cm_t35_panel_disable_tv(struct omap_dss_device *dssdev)
 
 static struct panel_generic_dpi_data lcd_panel = {
 	.name			= "toppoly_tdo35s",
-	.platform_enable	= cm_t35_panel_enable_lcd,
-	.platform_disable	= cm_t35_panel_disable_lcd,
+	.num_gpios		= 1,
+	.gpios			= {
+		CM_T35_LCD_BL_GPIO,
+	},
 };
 
 static struct omap_dss_device cm_t35_lcd_device = {
@@ -292,11 +268,6 @@ static struct spi_board_info cm_t35_lcd_spi_board_info[] __initdata = {
 	},
 };
 
-static struct gpio cm_t35_dss_gpios[] __initdata = {
-	{ CM_T35_LCD_EN_GPIO, GPIOF_OUT_INIT_LOW,  "lcd enable"    },
-	{ CM_T35_LCD_BL_GPIO, GPIOF_OUT_INIT_LOW,  "lcd bl enable" },
-};
-
 static void __init cm_t35_init_display(void)
 {
 	int err;
@@ -304,23 +275,21 @@ static void __init cm_t35_init_display(void)
 	spi_register_board_info(cm_t35_lcd_spi_board_info,
 				ARRAY_SIZE(cm_t35_lcd_spi_board_info));
 
-	err = gpio_request_array(cm_t35_dss_gpios,
-				 ARRAY_SIZE(cm_t35_dss_gpios));
+
+	err = gpio_request_one(CM_T35_LCD_EN_GPIO, GPIOF_OUT_INIT_LOW,
+			"lcd bl enable");
 	if (err) {
-		pr_err("CM-T35: failed to request DSS control GPIOs\n");
+		pr_err("CM-T35: failed to request LCD EN GPIO\n");
 		return;
 	}
 
-	gpio_export(CM_T35_LCD_EN_GPIO, 0);
-	gpio_export(CM_T35_LCD_BL_GPIO, 0);
-
 	msleep(50);
 	gpio_set_value(CM_T35_LCD_EN_GPIO, 1);
 
 	err = omap_display_init(&cm_t35_dss_data);
 	if (err) {
 		pr_err("CM-T35: failed to register DSS device\n");
-		gpio_free_array(cm_t35_dss_gpios, ARRAY_SIZE(cm_t35_dss_gpios));
+		gpio_free(CM_T35_LCD_EN_GPIO);
 	}
 }
 



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