diff options
Diffstat (limited to 'drivers/input/touchscreen/stmpe-ts.c')
| -rw-r--r-- | drivers/input/touchscreen/stmpe-ts.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/stmpe-ts.c b/drivers/input/touchscreen/stmpe-ts.c new file mode 100644 index 000000000000..77f4374b216d --- /dev/null +++ b/drivers/input/touchscreen/stmpe-ts.c @@ -0,0 +1,397 @@ +/* STMicroelectronics STMPE811 Touchscreen Driver + * + * (C) 2010 Luotao Fu <l.fu@pengutronix.de> + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/input.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/workqueue.h> + +#include <linux/mfd/stmpe.h> + +/* Register layouts and functionalities are identical on all stmpexxx variants + * with touchscreen controller + */ +#define STMPE_REG_INT_STA 0x0B +#define STMPE_REG_ADC_CTRL1 0x20 +#define STMPE_REG_ADC_CTRL2 0x21 +#define STMPE_REG_TSC_CTRL 0x40 +#define STMPE_REG_TSC_CFG 0x41 +#define STMPE_REG_FIFO_TH 0x4A +#define STMPE_REG_FIFO_STA 0x4B +#define STMPE_REG_FIFO_SIZE 0x4C +#define STMPE_REG_TSC_DATA_XYZ 0x52 +#define STMPE_REG_TSC_FRACTION_Z 0x56 +#define STMPE_REG_TSC_I_DRIVE 0x58 + +#define OP_MOD_XYZ 0 + +#define STMPE_TSC_CTRL_TSC_EN (1<<0) + +#define STMPE_FIFO_STA_RESET (1<<0) + +#define STMPE_IRQ_TOUCH_DET 0 + +#define SAMPLE_TIME(x) ((x & 0xf) << 4) +#define MOD_12B(x) ((x & 0x1) << 3) +#define REF_SEL(x) ((x & 0x1) << 1) +#define ADC_FREQ(x) (x & 0x3) +#define AVE_CTRL(x) ((x & 0x3) << 6) +#define DET_DELAY(x) ((x & 0x7) << 3) +#define SETTLING(x) (x & 0x7) +#define FRACTION_Z(x) (x & 0x7) +#define I_DRIVE(x) (x & 0x1) +#define OP_MODE(x) ((x & 0x7) << 1) + +#define STMPE_TS_NAME "stmpe-ts" +#define XY_MASK 0xfff + +struct stmpe_touch { + struct stmpe *stmpe; + struct input_dev *idev; + struct delayed_work work; + struct device *dev; + u8 sample_time; + u8 mod_12b; + u8 ref_sel; + u8 adc_freq; + u8 ave_ctrl; + u8 touch_det_delay; + u8 settling; + u8 fraction_z; + u8 i_drive; +}; + +static int __stmpe_reset_fifo(struct stmpe *stmpe) +{ + int ret; + + ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, + STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET); + if (ret) + return ret; + + return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA, + STMPE_FIFO_STA_RESET, 0); +} + +static void stmpe_work(struct work_struct *work) +{ + int int_sta; + u32 timeout = 40; + + struct stmpe_touch *ts = + container_of(work, struct stmpe_touch, work.work); + + int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); + + /* + * touch_det sometimes get desasserted or just get stuck. This appears + * to be a silicon bug, We still have to clearify this with the + * manufacture. As a workaround We release the key anyway if the + * touch_det keeps coming in after 4ms, while the FIFO contains no value + * during the whole time. + */ + while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) { + timeout--; + int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA); + udelay(100); + } + + /* reset the FIFO before we report release event */ + __stmpe_reset_fifo(ts->stmpe); + + input_report_abs(ts->idev, ABS_PRESSURE, 0); + input_sync(ts->idev); +} + +static irqreturn_t stmpe_ts_handler(int irq, void *data) +{ + u8 data_set[4]; + int x, y, z; + struct stmpe_touch *ts = data; + + /* + * Cancel scheduled polling for release if we have new value + * available. Wait if the polling is already running. + */ + cancel_delayed_work_sync(&ts->work); + + /* + * The FIFO sometimes just crashes and stops generating interrupts. This + * appears to be a silicon bug. We still have to clearify this with + * the manufacture. As a workaround we disable the TSC while we are + * collecting data and flush the FIFO after reading + */ + stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, + STMPE_TSC_CTRL_TSC_EN, 0); + + stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set); + + x = (data_set[0] << 4) | (data_set[1] >> 4); + y = ((data_set[1] & 0xf) << 8) | data_set[2]; + z = data_set[3]; + + input_report_abs(ts->idev, ABS_X, x); + input_report_abs(ts->idev, ABS_Y, y); + input_report_abs(ts->idev, ABS_PRESSURE, z); + input_sync(ts->idev); + + /* flush the FIFO after we have read out our values. */ + __stmpe_reset_fifo(ts->stmpe); + + /* reenable the tsc */ + stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, + STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); + + /* start polling for touch_det to detect release */ + schedule_delayed_work(&ts->work, HZ / 50); + + return IRQ_HANDLED; +} + +static int __devinit stmpe_init_hw(struct stmpe_touch *ts) +{ + int ret; + u8 adc_ctrl1, adc_ctrl1_mask, tsc_cfg, tsc_cfg_mask; + struct stmpe *stmpe = ts->stmpe; + struct device *dev = ts->dev; + + ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC); + if (ret) { + dev_err(dev, "Could not enable clock for ADC and TS\n"); + return ret; + } + + adc_ctrl1 = SAMPLE_TIME(ts->sample_time) | MOD_12B(ts->mod_12b) | + REF_SEL(ts->ref_sel); + adc_ctrl1_mask = SAMPLE_TIME(0xff) | MOD_12B(0xff) | REF_SEL(0xff); + + ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL1, + adc_ctrl1_mask, adc_ctrl1); + if (ret) { + dev_err(dev, "Could not setup ADC\n"); + return ret; + } + + ret = stmpe_set_bits(stmpe, STMPE_REG_ADC_CTRL2, + ADC_FREQ(0xff), ADC_FREQ(ts->adc_freq)); + if (ret) { + dev_err(dev, "Could not setup ADC\n"); + return ret; + } + + tsc_cfg = AVE_CTRL(ts->ave_ctrl) | DET_DELAY(ts->touch_det_delay) | + SETTLING(ts->settling); + tsc_cfg_mask = AVE_CTRL(0xff) | DET_DELAY(0xff) | SETTLING(0xff); + + ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg); + if (ret) { + dev_err(dev, "Could not config touch\n"); + return ret; + } + + ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z, + FRACTION_Z(0xff), FRACTION_Z(ts->fraction_z)); + if (ret) { + dev_err(dev, "Could not config touch\n"); + return ret; + } + + ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE, + I_DRIVE(0xff), I_DRIVE(ts->i_drive)); + if (ret) { + dev_err(dev, "Could not config touch\n"); + return ret; + } + + /* set FIFO to 1 for single point reading */ + ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1); + if (ret) { + dev_err(dev, "Could not set FIFO\n"); + return ret; + } + + ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL, + OP_MODE(0xff), OP_MODE(OP_MOD_XYZ)); + if (ret) { + dev_err(dev, "Could not set mode\n"); + return ret; + } + + return 0; +} + +static int stmpe_ts_open(struct input_dev *dev) +{ + struct stmpe_touch *ts = input_get_drvdata(dev); + int ret = 0; + + ret = __stmpe_reset_fifo(ts->stmpe); + if (ret) + return ret; + + return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, + STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN); +} + +static void stmpe_ts_close(struct input_dev *dev) +{ + struct stmpe_touch *ts = input_get_drvdata(dev); + + cancel_delayed_work_sync(&ts->work); + + stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL, + STMPE_TSC_CTRL_TSC_EN, 0); +} + +static int __devinit stmpe_input_probe(struct platform_device *pdev) +{ + struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent); + struct stmpe_platform_data *pdata = stmpe->pdata; + struct stmpe_touch *ts; + struct input_dev *idev; + struct stmpe_ts_platform_data *ts_pdata = NULL; + int ret = 0; + unsigned int ts_irq; + + ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); + if (ts_irq < 0) + return ts_irq; + + ts = kzalloc(sizeof(*ts), GFP_KERNEL); + if (!ts) + goto err_out; + + idev = input_allocate_device(); + if (!idev) + goto err_free_ts; + + platform_set_drvdata(pdev, ts); + ts->stmpe = stmpe; + ts->idev = idev; + ts->dev = &pdev->dev; + + if (pdata) + ts_pdata = pdata->ts; + + if (ts_pdata) { + ts->sample_time = ts_pdata->sample_time; + ts->mod_12b = ts_pdata->mod_12b; + ts->ref_sel = ts_pdata->ref_sel; + ts->adc_freq = ts_pdata->adc_freq; + ts->ave_ctrl = ts_pdata->ave_ctrl; + ts->touch_det_delay = ts_pdata->touch_det_delay; + ts->settling = ts_pdata->settling; + ts->fraction_z = ts_pdata->fraction_z; + ts->i_drive = ts_pdata->i_drive; + } + + INIT_DELAYED_WORK(&ts->work, stmpe_work); + + ret = request_threaded_irq(ts_irq, NULL, stmpe_ts_handler, + IRQF_ONESHOT, STMPE_TS_NAME, ts); + if (ret) { + dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq); + goto err_free_input; + } + + ret = stmpe_init_hw(ts); + if (ret) + goto err_free_irq; + + idev->name = STMPE_TS_NAME; + idev->id.bustype = BUS_I2C; + idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); + idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + + idev->open = stmpe_ts_open; + idev->close = stmpe_ts_close; + + input_set_drvdata(idev, ts); + + input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0); + input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0); + input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0); + + ret = input_register_device(idev); + if (ret) { + dev_err(&pdev->dev, "Could not register input device\n"); + goto err_free_irq; + } + + return ret; + +err_free_irq: + free_irq(ts_irq, ts); +err_free_input: + input_free_device(idev); + platform_set_drvdata(pdev, NULL); +err_free_ts: + kfree(ts); +err_out: + return ret; +} + +static int __devexit stmpe_ts_remove(struct platform_device *pdev) +{ + struct stmpe_touch *ts = platform_get_drvdata(pdev); + unsigned int ts_irq = platform_get_irq_byname(pdev, "FIFO_TH"); + + stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN); + + free_irq(ts_irq, ts); + + platform_set_drvdata(pdev, NULL); + + input_unregister_device(ts->idev); + input_free_device(ts->idev); + + kfree(ts); + + return 0; +} + +static struct platform_driver stmpe_ts_driver = { + .driver = { + .name = STMPE_TS_NAME, + .owner = THIS_MODULE, + }, + .probe = stmpe_input_probe, + .remove = __devexit_p(stmpe_ts_remove), +}; + +static int __init stmpe_ts_init(void) +{ + return platform_driver_register(&stmpe_ts_driver); +} + +module_init(stmpe_ts_init); + +static void __exit stmpe_ts_exit(void) +{ + platform_driver_unregister(&stmpe_ts_driver); +} + +module_exit(stmpe_ts_exit); + +MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); +MODULE_DESCRIPTION("STMPEXXX touchscreen driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" STMPE_TS_NAME); |