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/*
* Touchscreen driver for the tps6507x chip.
*
* Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
*
* Credits:
*
* Using code from tsc2007, MtekVision Co., Ltd.
*
* For licencing details see kernel-base/COPYING
*
* TPS65070, TPS65073, TPS650731, and TPS650732 support
* 10 bit touch screen interface.
*/
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/mfd/tps6507x.h>
#include <linux/input/tps6507x-ts.h>
#include <linux/delay.h>
#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
#define TPS_DEFAULT_MIN_PRESSURE 0x30
#define MAX_10BIT ((1 << 10) - 1)
#define TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
TPS6507X_ADCONFIG_START_CONVERSION | \
TPS6507X_ADCONFIG_INPUT_REAL_TSC)
#define TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)
struct ts_event {
u16 x;
u16 y;
u16 pressure;
};
struct tps6507x_ts {
struct device *dev;
struct input_dev *input;
struct tps6507x_dev *mfd;
char phys[32];
struct ts_event tc;
u16 min_pressure;
bool pendown;
};
static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
{
return tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
}
static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
{
return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
}
static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
u8 tsc_mode, u16 *value)
{
s32 ret;
u8 adc_status;
u8 result;
/* Route input signal to A/D converter */
ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
if (ret) {
dev_err(tsc->dev, "TSC mode read failed\n");
goto err;
}
/* Start A/D conversion */
ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
TPS6507X_ADCONFIG_CONVERT_TS);
if (ret) {
dev_err(tsc->dev, "ADC config write failed\n");
return ret;
}
do {
ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
&adc_status);
if (ret) {
dev_err(tsc->dev, "ADC config read failed\n");
goto err;
}
} while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);
ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
if (ret) {
dev_err(tsc->dev, "ADC result 2 read failed\n");
goto err;
}
*value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;
ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
if (ret) {
dev_err(tsc->dev, "ADC result 1 read failed\n");
goto err;
}
*value |= result;
dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);
err:
return ret;
}
/* Need to call tps6507x_adc_standby() after using A/D converter for the
* touch screen interrupt to work properly.
*/
static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
{
s32 ret;
u8 val;
ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
TPS6507X_ADCONFIG_INPUT_TSC);
if (ret)
return ret;
ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
TPS6507X_TSCMODE_STANDBY);
if (ret)
return ret;
ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
if (ret)
return ret;
while (val & TPS6507X_REG_TSC_INT) {
mdelay(10);
ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
if (ret)
return ret;
}
return ret;
}
static void tps6507x_ts_poll(struct input_dev *input_dev)
{
struct tps6507x_ts *tsc = input_get_drvdata(input_dev);
bool pendown;
s32 ret;
ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
&tsc->tc.pressure);
if (ret)
goto done;
pendown = tsc->tc.pressure > tsc->min_pressure;
if (unlikely(!pendown && tsc->pendown)) {
dev_dbg(tsc->dev, "UP\n");
input_report_key(input_dev, BTN_TOUCH, 0);
input_report_abs(input_dev, ABS_PRESSURE, 0);
input_sync(input_dev);
tsc->pendown = false;
}
if (pendown) {
if (!tsc->pendown) {
dev_dbg(tsc->dev, "DOWN\n");
input_report_key(input_dev, BTN_TOUCH, 1);
} else
dev_dbg(tsc->dev, "still down\n");
ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
&tsc->tc.x);
if (ret)
goto done;
ret = tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
&tsc->tc.y);
if (ret)
goto done;
input_report_abs(input_dev, ABS_X, tsc->tc.x);
input_report_abs(input_dev, ABS_Y, tsc->tc.y);
input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
input_sync(input_dev);
tsc->pendown = true;
}
done:
tps6507x_adc_standby(tsc);
}
static int tps6507x_ts_probe(struct platform_device *pdev)
{
struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
const struct tps6507x_board *tps_board;
const struct touchscreen_init_data *init_data;
struct tps6507x_ts *tsc;
struct input_dev *input_dev;
int error;
/*
* tps_board points to pmic related constants
* coming from the board-evm file.
*/
tps_board = dev_get_platdata(tps6507x_dev->dev);
if (!tps_board) {
dev_err(tps6507x_dev->dev,
"Could not find tps6507x platform data\n");
return -ENODEV;
}
/*
* init_data points to array of regulator_init structures
* coming from the board-evm file.
*/
init_data = tps_board->tps6507x_ts_init_data;
tsc = devm_kzalloc(&pdev->dev, sizeof(struct tps6507x_ts), GFP_KERNEL);
if (!tsc) {
dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
return -ENOMEM;
}
tsc->mfd = tps6507x_dev;
tsc->dev = tps6507x_dev->dev;
tsc->min_pressure = init_data ?
init_data->min_pressure : TPS_DEFAULT_MIN_PRESSURE;
snprintf(tsc->phys, sizeof(tsc->phys),
"%s/input0", dev_name(tsc->dev));
input_dev = devm_input_allocate_device(&pdev->dev);
if (!input_dev) {
dev_err(tsc->dev, "Failed to allocate polled input device.\n");
return -ENOMEM;
}
tsc->input = input_dev;
input_set_drvdata(input_dev, tsc);
input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);
input_dev->name = "TPS6507x Touchscreen";
input_dev->phys = tsc->phys;
input_dev->dev.parent = tsc->dev;
input_dev->id.bustype = BUS_I2C;
if (init_data) {
input_dev->id.vendor = init_data->vendor;
input_dev->id.product = init_data->product;
input_dev->id.version = init_data->version;
}
error = tps6507x_adc_standby(tsc);
if (error)
return error;
error = input_setup_polling(input_dev, tps6507x_ts_poll);
if (error)
return error;
input_set_poll_interval(input_dev,
init_data ? init_data->poll_period :
TSC_DEFAULT_POLL_PERIOD);
error = input_register_device(input_dev);
if (error)
return error;
return 0;
}
static struct platform_driver tps6507x_ts_driver = {
.driver = {
.name = "tps6507x-ts",
},
.probe = tps6507x_ts_probe,
};
module_platform_driver(tps6507x_ts_driver);
MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:tps6507x-ts");
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