[PATCH 1/3] ARM: pxa: palmtreo: fix lcd initialization on treo680

[Mike Dunn]

This patch gets the LCD working on my Palm Treo680.  Changing the Palm Centro
code is avoided (I don't have a Centro for testing at the moment), but some
initialization is shuffled around a bit.

This basically adds some code that manages the three gpios that interface to the
lcd on the Treo 680.  The precise role of each gpio in the hardware architecture
is not entirely clear to me; this patch is the result of trial-and-error and
observing how the PalmOS code initializes the lcd.

The need for this patch is not evident when Linux is loaded from PalmOS, because
at that point the lcd-related gpios have already been configured.  But when
booting the kernel by other means, this patch is required unless the bootloader
has performed the necessary initialializations.

Signed-off-by: Mike Dunn <mikedunn at newsguy.com>
---

I suspect that at least some of these changes may apply to the Centro as well.
When I get a hold of one, I will sort this all out.

 arch/arm/mach-pxa/include/mach/palmtreo.h |    3 +
 arch/arm/mach-pxa/palmtreo.c              |   59 +++++++++++++++++++++++++++--
 2 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-pxa/include/mach/palmtreo.h b/arch/arm/mach-pxa/include/mach/palmtreo.h
index 2d3f14e..3266194 100644
--- a/arch/arm/mach-pxa/include/mach/palmtreo.h
+++ b/arch/arm/mach-pxa/include/mach/palmtreo.h
@@ -44,6 +44,9 @@
 #define GPIO_NR_TREO680_VIBRATE_EN	44
 #define GPIO_NR_TREO680_KEYB_BL		24
 #define GPIO_NR_TREO680_BT_EN		43
+#define GPIO_NR_TREO680_LCD_POWER	77
+#define GPIO_NR_TREO680_LCD_EN		86
+#define GPIO_NR_TREO680_LCD_EN_N	25
 #endif /* CONFIG_MACH_TREO680 */
 
 /* Centro685 specific GPIOs */
diff --git a/arch/arm/mach-pxa/palmtreo.c b/arch/arm/mach-pxa/palmtreo.c
index 3f3c48f..dcc38a1 100644
--- a/arch/arm/mach-pxa/palmtreo.c
+++ b/arch/arm/mach-pxa/palmtreo.c
@@ -98,9 +98,6 @@ static unsigned long treo_pin_config[] __initdata = {
 	GPIO96_KP_MKOUT_6,
 	GPIO93_KP_DKIN_0 | WAKEUP_ON_LEVEL_HIGH,	/* Hotsync button */
 
-	/* LCD */
-	GPIOxx_LCD_TFT_16BPP,
-
 	/* Quick Capture Interface */
 	GPIO84_CIF_FV,
 	GPIO85_CIF_LV,
@@ -140,6 +137,12 @@ static unsigned long treo680_pin_config[] __initdata = {
 	/* MATRIX KEYPAD - different wake up source */
 	GPIO100_KP_MKIN_0 | WAKEUP_ON_LEVEL_HIGH,
 	GPIO99_KP_MKIN_5,
+
+	/* LCD... L_BIAS alt fn not configured on Treo680; is GPIO instead */
+	GPIOxx_LCD_16BPP,
+	GPIO74_LCD_FCLK,
+	GPIO75_LCD_LCLK,
+	GPIO76_LCD_PCLK,
 };
 #endif /* CONFIG_MACH_TREO680 */
 
@@ -155,6 +158,9 @@ static unsigned long centro685_pin_config[] __initdata = {
 	/* MATRIX KEYPAD - different wake up source */
 	GPIO100_KP_MKIN_0,
 	GPIO99_KP_MKIN_5 | WAKEUP_ON_LEVEL_HIGH,
+
+	/* LCD */
+	GPIOxx_LCD_TFT_16BPP,
 };
 #endif /* CONFIG_MACH_CENTRO */
 
@@ -411,7 +417,6 @@ static void __init palmphone_common_init(void)
 	pxa_set_btuart_info(NULL);
 	pxa_set_stuart_info(NULL);
 	palm27x_pm_init(TREO_STR_BASE);
-	palm27x_lcd_init(GPIO_NR_TREO_BL_POWER, &palm_320x320_new_lcd_mode);
 	palm27x_udc_init(GPIO_NR_TREO_USB_DETECT, GPIO_NR_TREO_USB_PULLUP, 1);
 	palm27x_irda_init(GPIO_NR_TREO_IR_EN);
 	palm27x_ac97_init(-1, -1, -1, 95);
@@ -424,10 +429,55 @@ static void __init palmphone_common_init(void)
 }
 
 #ifdef CONFIG_MACH_TREO680
+void __init treo680_lcd_init(void)
+{
+	unsigned int gpio;
+
+	/* drive all three gpios high initially */
+	const unsigned long flags = GPIOF_INIT_HIGH | GPIOF_DIR_OUT;
+
+	/*
+	 * This is likely the power to the lcd.  Toggling it low/high appears to
+	 * turn the lcd off/on.  Can be toggled after lcd is initialized without
+	 * any apparent adverse effects to the lcd operation.  Note that this
+	 * gpio line is used by the lcd controller as the L_BIAS signal, but
+	 * treo680 configures it as gpio.
+	 */
+	gpio = GPIO_NR_TREO680_LCD_POWER;
+	if (gpio_request_one(gpio, flags, "LCD power") < 0)
+		goto fail;
+
+	/*
+	 * These two are called enables, for lack of a better understanding.  If
+	 * either of these are toggled after the lcd is initialized, the image
+	 * becomes degraded.
+	 */
+	gpio = GPIO_NR_TREO680_LCD_EN;
+	if (gpio_request_one(gpio, flags, "LCD enable") < 0)
+		goto fail;
+	gpio = GPIO_NR_TREO680_LCD_EN_N;
+	if (gpio_request_one(gpio, flags, "LCD enable_n") < 0)
+		goto fail;
+
+	/* common lcd initialization */
+	palm27x_lcd_init(GPIO_NR_TREO_BL_POWER, &palm_320x320_new_lcd_mode);
+
+	/* driving this low turns LCD on */
+	gpio_set_value(GPIO_NR_TREO680_LCD_EN_N, 0);
+
+	return;
+ fail:
+	pr_err("gpio %d initialization failed\n", gpio);
+	gpio_free(GPIO_NR_TREO680_LCD_POWER);
+	gpio_free(GPIO_NR_TREO680_LCD_EN);
+	gpio_free(GPIO_NR_TREO680_LCD_EN_N);
+}
+
 static void __init treo680_init(void)
 {
 	pxa2xx_mfp_config(ARRAY_AND_SIZE(treo680_pin_config));
 	palmphone_common_init();
+	treo680_lcd_init();
 	palm27x_mmc_init(GPIO_NR_TREO_SD_DETECT_N, GPIO_NR_TREO680_SD_READONLY,
 			GPIO_NR_TREO680_SD_POWER, 0);
 }
@@ -438,6 +488,7 @@ static void __init centro_init(void)
 {
 	pxa2xx_mfp_config(ARRAY_AND_SIZE(centro685_pin_config));
 	palmphone_common_init();
+	palm27x_lcd_init(GPIO_NR_TREO_BL_POWER, &palm_320x320_new_lcd_mode);
 	palm27x_mmc_init(GPIO_NR_TREO_SD_DETECT_N, -1,
 			GPIO_NR_CENTRO_SD_POWER, 1);
 }
-- 
1.7.8.6