ARM: Add ADS7846 touchscreen support to Overo platform

An upcoming Overo expansion board includes an ADS7846 touchscreen controller.

This patch adds support via the ads7846 driver when enabled in the
kernel config.

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/board-overo.c b/arch/arm/mach-omap2/board-overo.c
index 0f07b7b553d239291edc8eb6f05558cdc1b8d403..cf84c6a872ef247690ba645347829750a69c0ca0 100644 (file)
--- a/arch/arm/mach-omap2/board-overo.c
+++ b/arch/arm/mach-omap2/board-overo.c
@@ -116,6 +116,66 @@ static inline void __init overo_init_smsc911x(void)
 static inline void __init overo_init_smsc911x(void) { return; }
 #endif
 
+#if defined(CONFIG_TOUCHSCREEN_ADS7846) || \
+       defined(CONFIG_TOUCHSCREEN_ADS7846_MODULE)
+
+#include <mach/mcspi.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ads7846.h>
+
+static struct omap2_mcspi_device_config ads7846_mcspi_config = {
+       .turbo_mode     = 0,
+       .single_channel = 1,    /* 0: slave, 1: master */
+};
+
+
+static int ads7846_get_pendown_state(void)
+{
+       return !gpio_get_value(OVERO_GPIO_PENDOWN);
+}
+
+static struct ads7846_platform_data ads7846_config = {
+       .x_max                  = 0x0fff,
+       .y_max                  = 0x0fff,
+       .x_plate_ohms           = 180,
+       .pressure_max           = 255,
+       .debounce_max           = 10,
+       .debounce_tol           = 3,
+       .debounce_rep           = 1,
+       .get_pendown_state      = ads7846_get_pendown_state,
+       .keep_vref_on           = 1,
+};
+
+static struct spi_board_info overo_spi_board_info[] __initdata = {
+       {
+               .modalias               = "ads7846",
+               .bus_num                = 1,
+               .chip_select            = 0,
+               .max_speed_hz           = 1500000,
+               .controller_data        = &ads7846_mcspi_config,
+               .irq                    = OMAP_GPIO_IRQ(OVERO_GPIO_PENDOWN),
+               .platform_data          = &ads7846_config,
+       }
+};
+
+static void __init overo_ads7846_init(void)
+{
+       if ((gpio_request(OVERO_GPIO_PENDOWN, "ADS7846_PENDOWN") == 0) &&
+           (gpio_direction_input(OVERO_GPIO_PENDOWN) == 0)) {
+               gpio_export(OVERO_GPIO_PENDOWN, 0);
+       } else {
+               printk(KERN_ERR "could not obtain gpio for ADS7846_PENDOWN\n");
+               return;
+       }
+
+       spi_register_board_info(overo_spi_board_info,
+                       ARRAY_SIZE(overo_spi_board_info));
+}
+
+#else
+static inline void __init overo_ads7846_init(void) { return; }
+#endif
+
 static struct mtd_partition overo_nand_partitions[] = {
        {
                .name           = "xloader",
@@ -310,6 +370,7 @@ static void __init overo_init(void)
        usb_ehci_init();
        overo_flash_init();
        overo_init_smsc911x();
+       overo_ads7846_init();
 
        if ((gpio_request(OVERO_GPIO_W2W_NRESET,
                          "OVERO_GPIO_W2W_NRESET") == 0) &&

diff --git a/arch/arm/plat-omap/include/mach/board-overo.h b/arch/arm/plat-omap/include/mach/board-overo.h
index 8635171bac33afc7092952f8eebd6e42bbf6bf9f..aca717d6593f7188f60476b057a6e88f1507a2a1 100644 (file)
--- a/arch/arm/plat-omap/include/mach/board-overo.h
+++ b/arch/arm/plat-omap/include/mach/board-overo.h
@@ -18,6 +18,7 @@
 
 #define OVERO_GPIO_BT_XGATE    15
 #define OVERO_GPIO_W2W_NRESET  16
+#define OVERO_GPIO_PENDOWN     114
 #define OVERO_GPIO_BT_NRESET   164
 #define OVERO_GPIO_USBH_CPEN   168
 #define OVERO_GPIO_USBH_NRESET 183