381 lines
9.8 KiB
C
381 lines
9.8 KiB
C
/*
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* STMicroelectronics STMPE811 Touchscreen Driver
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*
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* (C) 2010 Luotao Fu <l.fu@pengutronix.de>
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/interrupt.h>
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#include <linux/device.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/input.h>
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#include <linux/slab.h>
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#include <linux/delay.h>
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#include <linux/i2c.h>
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#include <linux/workqueue.h>
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#include <linux/mfd/stmpe.h>
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/* Register layouts and functionalities are identical on all stmpexxx variants
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* with touchscreen controller
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*/
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#define STMPE_REG_INT_STA 0x0B
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#define STMPE_REG_TSC_CTRL 0x40
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#define STMPE_REG_TSC_CFG 0x41
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#define STMPE_REG_FIFO_TH 0x4A
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#define STMPE_REG_FIFO_STA 0x4B
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#define STMPE_REG_FIFO_SIZE 0x4C
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#define STMPE_REG_TSC_DATA_XYZ 0x52
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#define STMPE_REG_TSC_FRACTION_Z 0x56
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#define STMPE_REG_TSC_I_DRIVE 0x58
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#define OP_MOD_XYZ 0
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#define STMPE_TSC_CTRL_TSC_EN (1<<0)
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#define STMPE_FIFO_STA_RESET (1<<0)
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#define STMPE_IRQ_TOUCH_DET 0
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#define STMPE_TS_NAME "stmpe-ts"
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#define XY_MASK 0xfff
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/**
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* struct stmpe_touch - stmpe811 touch screen controller state
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* @stmpe: pointer back to STMPE MFD container
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* @idev: registered input device
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* @work: a work item used to scan the device
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* @dev: a pointer back to the MFD cell struct device*
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* @ave_ctrl: Sample average control
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* (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples)
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* @touch_det_delay: Touch detect interrupt delay
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* (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us,
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* 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms)
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* recommended is 3
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* @settling: Panel driver settling time
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* (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms,
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* 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms)
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* recommended is 2
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* @fraction_z: Length of the fractional part in z
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* (fraction_z ([0..7]) = Count of the fractional part)
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* recommended is 7
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* @i_drive: current limit value of the touchscreen drivers
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* (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max)
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*/
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struct stmpe_touch {
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struct stmpe *stmpe;
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struct input_dev *idev;
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struct delayed_work work;
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struct device *dev;
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u8 ave_ctrl;
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u8 touch_det_delay;
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u8 settling;
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u8 fraction_z;
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u8 i_drive;
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};
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static int __stmpe_reset_fifo(struct stmpe *stmpe)
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{
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int ret;
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ret = stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
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STMPE_FIFO_STA_RESET, STMPE_FIFO_STA_RESET);
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if (ret)
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return ret;
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return stmpe_set_bits(stmpe, STMPE_REG_FIFO_STA,
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STMPE_FIFO_STA_RESET, 0);
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}
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static void stmpe_work(struct work_struct *work)
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{
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int int_sta;
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u32 timeout = 40;
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struct stmpe_touch *ts =
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container_of(work, struct stmpe_touch, work.work);
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int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
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/*
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* touch_det sometimes get desasserted or just get stuck. This appears
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* to be a silicon bug, We still have to clearify this with the
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* manufacture. As a workaround We release the key anyway if the
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* touch_det keeps coming in after 4ms, while the FIFO contains no value
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* during the whole time.
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*/
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while ((int_sta & (1 << STMPE_IRQ_TOUCH_DET)) && (timeout > 0)) {
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timeout--;
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int_sta = stmpe_reg_read(ts->stmpe, STMPE_REG_INT_STA);
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udelay(100);
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}
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/* reset the FIFO before we report release event */
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__stmpe_reset_fifo(ts->stmpe);
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input_report_abs(ts->idev, ABS_PRESSURE, 0);
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input_report_key(ts->idev, BTN_TOUCH, 0);
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input_sync(ts->idev);
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}
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static irqreturn_t stmpe_ts_handler(int irq, void *data)
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{
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u8 data_set[4];
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int x, y, z;
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struct stmpe_touch *ts = data;
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/*
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* Cancel scheduled polling for release if we have new value
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* available. Wait if the polling is already running.
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*/
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cancel_delayed_work_sync(&ts->work);
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/*
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* The FIFO sometimes just crashes and stops generating interrupts. This
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* appears to be a silicon bug. We still have to clearify this with
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* the manufacture. As a workaround we disable the TSC while we are
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* collecting data and flush the FIFO after reading
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*/
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stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
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STMPE_TSC_CTRL_TSC_EN, 0);
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stmpe_block_read(ts->stmpe, STMPE_REG_TSC_DATA_XYZ, 4, data_set);
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x = (data_set[0] << 4) | (data_set[1] >> 4);
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y = ((data_set[1] & 0xf) << 8) | data_set[2];
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z = data_set[3];
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input_report_abs(ts->idev, ABS_X, x);
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input_report_abs(ts->idev, ABS_Y, y);
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input_report_abs(ts->idev, ABS_PRESSURE, z);
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input_report_key(ts->idev, BTN_TOUCH, 1);
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input_sync(ts->idev);
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/* flush the FIFO after we have read out our values. */
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__stmpe_reset_fifo(ts->stmpe);
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/* reenable the tsc */
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stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
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STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
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/* start polling for touch_det to detect release */
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schedule_delayed_work(&ts->work, msecs_to_jiffies(50));
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return IRQ_HANDLED;
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}
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static int stmpe_init_hw(struct stmpe_touch *ts)
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{
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int ret;
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u8 tsc_cfg, tsc_cfg_mask;
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struct stmpe *stmpe = ts->stmpe;
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struct device *dev = ts->dev;
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ret = stmpe_enable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
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if (ret) {
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dev_err(dev, "Could not enable clock for ADC and TS\n");
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return ret;
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}
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ret = stmpe811_adc_common_init(stmpe);
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if (ret) {
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stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
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return ret;
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}
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tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) |
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STMPE_DET_DELAY(ts->touch_det_delay) |
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STMPE_SETTLING(ts->settling);
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tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) |
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STMPE_SETTLING(0xff);
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ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CFG, tsc_cfg_mask, tsc_cfg);
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if (ret) {
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dev_err(dev, "Could not config touch\n");
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return ret;
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}
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ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_FRACTION_Z,
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STMPE_FRACTION_Z(0xff), STMPE_FRACTION_Z(ts->fraction_z));
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if (ret) {
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dev_err(dev, "Could not config touch\n");
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return ret;
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}
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ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_I_DRIVE,
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STMPE_I_DRIVE(0xff), STMPE_I_DRIVE(ts->i_drive));
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if (ret) {
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dev_err(dev, "Could not config touch\n");
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return ret;
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}
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/* set FIFO to 1 for single point reading */
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ret = stmpe_reg_write(stmpe, STMPE_REG_FIFO_TH, 1);
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if (ret) {
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dev_err(dev, "Could not set FIFO\n");
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return ret;
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}
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ret = stmpe_set_bits(stmpe, STMPE_REG_TSC_CTRL,
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STMPE_OP_MODE(0xff), STMPE_OP_MODE(OP_MOD_XYZ));
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if (ret) {
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dev_err(dev, "Could not set mode\n");
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return ret;
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}
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return 0;
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}
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static int stmpe_ts_open(struct input_dev *dev)
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{
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struct stmpe_touch *ts = input_get_drvdata(dev);
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int ret = 0;
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ret = __stmpe_reset_fifo(ts->stmpe);
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if (ret)
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return ret;
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return stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
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STMPE_TSC_CTRL_TSC_EN, STMPE_TSC_CTRL_TSC_EN);
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}
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static void stmpe_ts_close(struct input_dev *dev)
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{
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struct stmpe_touch *ts = input_get_drvdata(dev);
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cancel_delayed_work_sync(&ts->work);
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stmpe_set_bits(ts->stmpe, STMPE_REG_TSC_CTRL,
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STMPE_TSC_CTRL_TSC_EN, 0);
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}
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static void stmpe_ts_get_platform_info(struct platform_device *pdev,
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struct stmpe_touch *ts)
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{
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struct device_node *np = pdev->dev.of_node;
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u32 val;
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if (np) {
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if (!of_property_read_u32(np, "st,sample-time", &val))
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ts->stmpe->sample_time = val;
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if (!of_property_read_u32(np, "st,mod-12b", &val))
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ts->stmpe->mod_12b = val;
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if (!of_property_read_u32(np, "st,ref-sel", &val))
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ts->stmpe->ref_sel = val;
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if (!of_property_read_u32(np, "st,adc-freq", &val))
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ts->stmpe->adc_freq = val;
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if (!of_property_read_u32(np, "st,ave-ctrl", &val))
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ts->ave_ctrl = val;
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if (!of_property_read_u32(np, "st,touch-det-delay", &val))
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ts->touch_det_delay = val;
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if (!of_property_read_u32(np, "st,settling", &val))
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ts->settling = val;
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if (!of_property_read_u32(np, "st,fraction-z", &val))
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ts->fraction_z = val;
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if (!of_property_read_u32(np, "st,i-drive", &val))
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ts->i_drive = val;
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}
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}
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static int stmpe_input_probe(struct platform_device *pdev)
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{
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struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
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struct stmpe_touch *ts;
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struct input_dev *idev;
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int error;
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int ts_irq;
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ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
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if (ts_irq < 0)
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return ts_irq;
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ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
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if (!ts)
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return -ENOMEM;
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idev = devm_input_allocate_device(&pdev->dev);
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if (!idev)
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return -ENOMEM;
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platform_set_drvdata(pdev, ts);
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ts->stmpe = stmpe;
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ts->idev = idev;
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ts->dev = &pdev->dev;
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stmpe_ts_get_platform_info(pdev, ts);
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INIT_DELAYED_WORK(&ts->work, stmpe_work);
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error = devm_request_threaded_irq(&pdev->dev, ts_irq,
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NULL, stmpe_ts_handler,
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IRQF_ONESHOT, STMPE_TS_NAME, ts);
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if (error) {
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dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
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return error;
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}
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error = stmpe_init_hw(ts);
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if (error)
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return error;
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idev->name = STMPE_TS_NAME;
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idev->phys = STMPE_TS_NAME"/input0";
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idev->id.bustype = BUS_I2C;
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idev->open = stmpe_ts_open;
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idev->close = stmpe_ts_close;
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input_set_drvdata(idev, ts);
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input_set_capability(idev, EV_KEY, BTN_TOUCH);
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input_set_abs_params(idev, ABS_X, 0, XY_MASK, 0, 0);
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input_set_abs_params(idev, ABS_Y, 0, XY_MASK, 0, 0);
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input_set_abs_params(idev, ABS_PRESSURE, 0x0, 0xff, 0, 0);
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error = input_register_device(idev);
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if (error) {
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dev_err(&pdev->dev, "Could not register input device\n");
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return error;
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}
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return 0;
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}
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static int stmpe_ts_remove(struct platform_device *pdev)
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{
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struct stmpe_touch *ts = platform_get_drvdata(pdev);
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stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
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return 0;
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}
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static struct platform_driver stmpe_ts_driver = {
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.driver = {
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.name = STMPE_TS_NAME,
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},
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.probe = stmpe_input_probe,
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.remove = stmpe_ts_remove,
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};
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module_platform_driver(stmpe_ts_driver);
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static const struct of_device_id stmpe_ts_ids[] = {
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{ .compatible = "st,stmpe-ts", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, stmpe_ts_ids);
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MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
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MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
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MODULE_LICENSE("GPL");
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