[ARM] 4354/1: AT91: Support ADS7846 touchsceen on SAM9263-EK board

Add support for the ADS7846 Touchscreen found on the Atmel
AT91SAM9263-EK board.

Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 48 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/board-sam9263ek.c b/arch/arm/mach-at91/board-sam9263ek.c
index 8fdce11a880c..81d3d6a0a86a 100644
--- a/arch/arm/mach-at91/board-sam9263ek.c
+++ b/arch/arm/mach-at91/board-sam9263ek.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 <asm/hardware.h>
 #include <asm/setup.h>
@@ -86,6 +87,40 @@ static struct at91_udc_data __initdata ek_udc_data = {
 
 
 /*
+ * 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_PA15);     /* 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_PA15, 1);    /* External IRQ1, with pullup */
+        at91_set_gpio_input(AT91_PIN_PA31, 1);  /* Touchscreen BUSY signal */
+}
+#else
+static void __init ek_add_device_ts(void) {}
+#endif
+
+/*
  * SPI devices.
  */
 static struct spi_board_info ek_spi_devices[] = {
@@ -97,6 +132,16 @@ static struct spi_board_info ek_spi_devices[] = {
                 .bus_num        = 0,
         },
 #endif
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) || defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+        {
+                .modalias       = "ads7846",
+                .chip_select    = 3,
+                .max_speed_hz   = 125000 * 26,  /* (max sample rate @ 3V) * (cmd + data + overhead) */
+                .bus_num        = 0,
+                .platform_data  = &ads_info,
+                .irq            = AT91SAM9263_ID_IRQ1,
+        },
+#endif
 };
 
 
@@ -157,7 +202,10 @@ static void __init ek_board_init(void)
         /* USB Device */
         at91_add_device_udc(&ek_udc_data);
         /* SPI */
+        at91_set_gpio_output(AT91_PIN_PE20, 1);         /* select spi0 clock */
         at91_add_device_spi(ek_spi_devices, ARRAY_SIZE(ek_spi_devices));
+        /* Touchscreen */
+        ek_add_device_ts();
         /* MMC */
         at91_add_device_mmc(1, &ek_mmc_data);
         /* NAND */