ARM: spitz: Use software nodes for the ADS7846 touchscreen

Convert the Spitz to use software nodes to describe GPIOs for the
ADS7846 touchscreen. As part of the conversion switch from the custom
wait_for_sync() callback to defining hsync GPIO that can be used by
the ads7846 driver to detect hsync.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240628180852.1738922-11-dmitry.torokhov@gmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: linusw

arch/arm/mach-pxa/spitz.c

@@ -534,31 +534,23 @@ static inline void spitz_leds_init(void) {}
  * SSP Devices
  ******************************************************************************/
 #if defined(CONFIG_SPI_PXA2XX) || defined(CONFIG_SPI_PXA2XX_MODULE)
-static void spitz_ads7846_wait_for_hsync(void)
-{
-	while (gpio_get_value(SPITZ_GPIO_HSYNC))
-		cpu_relax();
-
-	while (!gpio_get_value(SPITZ_GPIO_HSYNC))
-		cpu_relax();
-}
 
-static struct ads7846_platform_data spitz_ads7846_info = {
-	.model			= 7846,
-	.vref_delay_usecs	= 100,
-	.x_plate_ohms		= 419,
-	.y_plate_ohms		= 486,
-	.pressure_max		= 1024,
-	.wait_for_sync		= spitz_ads7846_wait_for_hsync,
+static const struct property_entry spitz_ads7846_props[] = {
+	PROPERTY_ENTRY_STRING("compatible", "ti,ads7846"),
+	PROPERTY_ENTRY_U32("touchscreen-max-pressure", 1024),
+	PROPERTY_ENTRY_U16("ti,x-plate-ohms", 419),
+	PROPERTY_ENTRY_U16("ti,y-plate-ohms", 486),
+	PROPERTY_ENTRY_U16("ti,vref-delay-usecs", 100),
+	PROPERTY_ENTRY_GPIO("pendown-gpios", &pxa2xx_gpiochip_node,
+			    SPITZ_GPIO_TP_INT, GPIO_ACTIVE_LOW),
+	PROPERTY_ENTRY_GPIO("ti,hsync-gpios", &pxa2xx_gpiochip_node,
+			    SPITZ_GPIO_HSYNC, GPIO_ACTIVE_LOW),
+	{ }
 };
 
-static struct gpiod_lookup_table spitz_ads7846_gpio_table = {
-	.dev_id = "spi2.0",
-	.table = {
-		GPIO_LOOKUP("gpio-pxa", SPITZ_GPIO_TP_INT,
-			    "pendown", GPIO_ACTIVE_LOW),
-		{ }
-	},
+static const struct software_node spitz_ads7846_swnode = {
+	.name = "ads7846",
+	.properties = spitz_ads7846_props,
 };
 
 static const struct property_entry spitz_lcdcon_props[] = {
@@ -595,7 +587,7 @@ static struct spi_board_info spitz_spi_devices[] = {
 		.max_speed_hz		= 1200000,
 		.bus_num		= 2,
 		.chip_select		= 0,
-		.platform_data		= &spitz_ads7846_info,
+		.swnode			= &spitz_ads7846_swnode,
 		.irq			= PXA_GPIO_TO_IRQ(SPITZ_GPIO_TP_INT),
 	}, {
 		.modalias		= "corgi-lcd",
@@ -638,8 +630,6 @@ static void __init spitz_spi_init(void)
 	struct platform_device *pd;
 	int err;
 
-	gpiod_add_lookup_table(&spitz_ads7846_gpio_table);
-
 	pd = platform_device_register_full(&spitz_spi_device_info);
 	err = PTR_ERR_OR_ZERO(pd);
 	if (err)