[ARM] 4353/1: AT91: Support ADS7846 touchsceen on SAM9261-EK board

Add support for the ADS7846 Touchscreen found on the Atmel
AT91SAM9261-EK board.

Original patch by Morten Larsen.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-at91/board-sam9261ek.c

@@ -25,6 +25,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
 #include <linux/dm9000.h>
 
 #include <asm/hardware.h>
@@ -194,6 +195,41 @@ static struct at91_nand_data __initdata ek_nand_data = {
 #endif
 };
 
+/*
+ * ADS7846 Touchscreen
+ */
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) || defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+
+static int ads7843_pendown_state(void)
+{
+	return !at91_get_gpio_value(AT91_PIN_PC2);	/* Touchscreen PENIRQ */
+}
+
+static struct ads7846_platform_data ads_info = {
+	.model			= 7843,
+	.x_min			= 150,
+	.x_max			= 3830,
+	.y_min			= 190,
+	.y_max			= 3830,
+	.vref_delay_usecs	= 100,
+	.x_plate_ohms		= 450,
+	.y_plate_ohms		= 250,
+	.pressure_max		= 15000,
+	.debounce_max		= 1,
+	.debounce_rep		= 0,
+	.debounce_tol		= (~0),
+	.get_pendown_state	= ads7843_pendown_state,
+};
+
+static void __init ek_add_device_ts(void)
+{
+	at91_set_B_periph(AT91_PIN_PC2, 1);	/* External IRQ0, with pullup */
+	at91_set_gpio_input(AT91_PIN_PA11, 1);	/* Touchscreen BUSY signal */
+}
+#else
+static void __init ek_add_device_ts(void) {}
+#endif
+
 /*
  * SPI devices
  */
@@ -204,16 +240,26 @@ static struct spi_board_info ek_spi_devices[] = {
 		.max_speed_hz	= 15 * 1000 * 1000,
 		.bus_num	= 0,
 	},
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) || defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+	{
+		.modalias	= "ads7846",
+		.chip_select	= 2,
+		.max_speed_hz	= 125000 * 26,	/* (max sample rate @ 3V) * (cmd + data + overhead) */
+		.bus_num	= 0,
+		.platform_data	= &ads_info,
+		.irq		= AT91SAM9261_ID_IRQ0,
+	},
+#endif
 #if defined(CONFIG_MTD_AT91_DATAFLASH_CARD)
 	{	/* DataFlash card - jumper (J12) configurable to CS3 or CS0 */
 		.modalias	= "mtd_dataflash",
 		.chip_select	= 3,
 		.max_speed_hz	= 15 * 1000 * 1000,
 		.bus_num	= 0,
 	},
-#elif defined(CONFIG_SND_AT73C213)
+#elif defined(CONFIG_SND_AT73C213) || defined(CONFIG_SND_AT73C213_MODULE)
 	{	/* AT73C213 DAC */
-		.modalias	= "snd_at73c213",
+		.modalias	= "at73c213",
 		.chip_select	= 3,
 		.max_speed_hz	= 10 * 1000 * 1000,
 		.bus_num	= 0,
@@ -241,6 +287,8 @@ static void __init ek_board_init(void)
 #if defined(CONFIG_SPI_ATMEL) || defined(CONFIG_SPI_ATMEL_MODULE)
 	/* SPI */
 	at91_add_device_spi(ek_spi_devices, ARRAY_SIZE(ek_spi_devices));
+	/* Touchscreen */
+	ek_add_device_ts();
 #else
 	/* MMC */
 	at91_add_device_mmc(0, &ek_mmc_data);