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

From: [email-masked] (Petr Cvek)
Date: Mon, 12 Oct 2015 06:39:54 +0200

Dne 3.10.2015 v 14:49 Philipp Zabel napsal(a):
> Am Montag, den 28.09.2015, 23:38 +0200 schrieb Petr Cvek:
>> Add support for an ADS7846 touchscreen.
> 
> It's actually a TSC2045.

2046...,  but I will mention it in next commit message (it was name of the driver).

> 
>> 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.

Will change to something more visible, probably remnants of some debugging.
BTW It sets frequency of a SPI? 

> 
>> +		.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
> 

Petr