Subject: [PATCH v3 18/26] ARM: pxa: magician: Add support for ADS7846

From: [email-masked] (Petr Cvek)
Date: Fri, 18 Sep 2015 03:18:00 +0200

Add support for an ADS7846 touchscreen.

Signed-off-by: Petr Cvek <[email-masked]>
---
 arch/arm/mach-pxa/magician.c | 86 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)

diff --git a/arch/arm/mach-pxa/magician.c b/arch/arm/mach-pxa/magician.c
index af8133a..450f35f 100644
--- a/arch/arm/mach-pxa/magician.c
+++ b/arch/arm/mach-pxa/magician.c
@@ -28,6 +28,7 @@
 #include <linux/pwm_backlight.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/gpio-regulator.h>
+#include <linux/regulator/fixed.h>
 #include <linux/regulator/machine.h>
 #include <linux/usb/gpio_vbus.h>
 #include <linux/i2c/pxa-i2c.h>
@@ -44,6 +45,10 @@
 #include <linux/platform_data/irda-pxaficp.h>
 #include <linux/platform_data/usb-ohci-pxa27x.h>
 
+#include <linux/spi/spi.h>
+#include <linux/spi/pxa2xx_spi.h>
+#include <linux/spi/ads7846.h>
+
 #include "devices.h"
 #include "generic.h"
 
@@ -748,6 +753,37 @@ static struct platform_device bq24022 = {
 };
 
 /*
+ * fixed regulator for ads7846
+ */
+
+static struct regulator_consumer_supply ads7846_supply =
+	REGULATOR_SUPPLY("vcc", "spi2.0");
+
+static struct regulator_init_data vads7846_regulator = {
+	.constraints = {
+		.valid_ops_mask	= REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies	= 1,
+	.consumer_supplies	= &ads7846_supply,
+};
+
+static struct fixed_voltage_config vads7846 = {
+	.supply_name	= "vads7846",
+	.microvolts	= 3300000, /* probably */
+	.gpio		= -EINVAL,
+	.startup_delay	= 0,
+	.init_data	= &vads7846_regulator,
+};
+
+static struct platform_device vads7846_device = {
+	.name	= "reg-fixed-voltage",
+	.id	= 1,
+	.dev	= {
+		.platform_data = &vads7846,
+	},
+};
+
+/*
  * MMC/SD
  */
 
@@ -879,6 +915,51 @@ static struct i2c_pxa_platform_data magician_i2c_power_info = {
 };
 
 /*
+ * Touchscreen
+ */
+
+static struct ads7846_platform_data ads7846_pdata = {
+	.model			= 7846,
+	.x_min			= 0,
+	.y_min			= 0,
+	.x_max			= 4096,
+	.y_max			= 4096,
+	.x_plate_ohms		= 180,	/* for pressure in 0-255 */
+	.y_plate_ohms		= 180,
+	.pressure_max		= 255,	/* up to 12bit sampling */
+	.debounce_max		= 10,
+	.debounce_tol		= 3,
+	.debounce_rep		= 1,
+	.gpio_pendown		= GPIO115_MAGICIAN_nPEN_IRQ,
+	.keep_vref_on		= 1,	/* FIXME, external Vref? */
+	.vref_delay_usecs	= 100,
+	/* .wait_for_sync, GPIO77_LCD_BIAS low noise measure, latency! */
+};
+
+struct pxa2xx_spi_chip tsc2046_chip_info = {
+	.tx_threshold	= 1,
+	.rx_threshold	= 2,
+	.timeout	= 64,
+	.gpio_cs	= -1,
+};
+
+static struct pxa2xx_spi_master magician_spi_info = {
+	.num_chipselect	= 1,
+	.enable_dma	= 1,
+};
+
+static struct spi_board_info ads7846_spi_board_info[] __initdata = {
+	{
+		.modalias		= "ads7846",
+		.bus_num		= 2,
+		.max_speed_hz		= 1857143,
+		.platform_data		= &ads7846_pdata,
+		.controller_data	= &tsc2046_chip_info,
+		.irq = PXA_GPIO_TO_IRQ(GPIO115_MAGICIAN_nPEN_IRQ),
+	},
+};
+
+/*
  * Platform devices
  */
 
@@ -887,6 +968,7 @@ static struct platform_device *devices[] __initdata = {
 	&egpio,
 	&backlight,
 	&pasic3,
+	&vads7846_device,
 	&bq24022,
 	&gpio_vbus,
 	&power_supply,
@@ -944,6 +1026,10 @@ static void __init magician_init(void)
 			lcd_select ? &samsung_info : &toppoly_info);
 	} else
 		pr_err("LCD detection: CPLD mapping failed\n");
+
+	pxa2xx_set_spi_info(2, &magician_spi_info);
+	spi_register_board_info(ARRAY_AND_SIZE(ads7846_spi_board_info));
+
 }
 
 MACHINE_START(MAGICIAN, "HTC Magician")
-- 
1.7.12.1