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

From: Philipp Zabel
Date: Sat Oct 03 2015 - 08:49:31 EST


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 <petr.cvek@xxxxxx>
> ---
> 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
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