diff options
Diffstat (limited to 'drivers/input/touchscreen/tps6507x-ts.c')
| -rw-r--r-- | drivers/input/touchscreen/tps6507x-ts.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/tps6507x-ts.c b/drivers/input/touchscreen/tps6507x-ts.c new file mode 100644 index 000000000..357a3108f --- /dev/null +++ b/drivers/input/touchscreen/tps6507x-ts.c @@ -0,0 +1,294 @@ +/* + * 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; + s32 loops = 0; + 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; + loops++; + } + + 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"); |