Subject: [PATCH v4 18/26] ARM: pxa: magician: Add support for ADS7846

From: [email-masked] (Philipp Zabel)
Date: Sat, 03 Oct 2015 14:49:24 +0200

Am Montag, den 28.09.2015, 23:38 +0200 schrieb Petr Cvek:
> Add support for an ADS7846 touchscreen.

It's actually a TSC2045.

> 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 */

I agree.

> +	.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,

I had used 2.6 MHz here.

> +		.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_inf
> o));
> +
>  }
>  
>  MACHINE_START(MAGICIAN, "HTC Magician")

regards
Philipp