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linux/drivers/input/touchscreen/stmpe-ts.c

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* STMicroelectronics STMPE811 Touchscreen Driver
*
* (C) 2010 Luotao Fu <l.fu@pengutronix.de>
* All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/of.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_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 STMPE_TS_NAME "stmpe-ts"
#define XY_MASK 0xfff
/**
* struct stmpe_touch - stmpe811 touch screen controller state
* @stmpe: pointer back to STMPE MFD container
* @idev: registered input device
* @work: a work item used to scan the device
* @dev: a pointer back to the MFD cell struct device*
* @ave_ctrl: Sample average control
* (0 -> 1 sample, 1 -> 2 samples, 2 -> 4 samples, 3 -> 8 samples)
* @touch_det_delay: Touch detect interrupt delay
* (0 -> 10 us, 1 -> 50 us, 2 -> 100 us, 3 -> 500 us,
* 4-> 1 ms, 5 -> 5 ms, 6 -> 10 ms, 7 -> 50 ms)
* recommended is 3
* @settling: Panel driver settling time
* (0 -> 10 us, 1 -> 100 us, 2 -> 500 us, 3 -> 1 ms,
* 4 -> 5 ms, 5 -> 10 ms, 6 for 50 ms, 7 -> 100 ms)
* recommended is 2
* @fraction_z: Length of the fractional part in z
* (fraction_z ([0..7]) = Count of the fractional part)
* recommended is 7
* @i_drive: current limit value of the touchscreen drivers
* (0 -> 20 mA typical 35 mA max, 1 -> 50 mA typical 80 mA max)
*/
struct stmpe_touch {
struct stmpe *stmpe;
struct input_dev *idev;
struct delayed_work work;
struct device *dev;
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_report_key(ts->idev, BTN_TOUCH, 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_report_key(ts->idev, BTN_TOUCH, 1);
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, msecs_to_jiffies(50));
return IRQ_HANDLED;
}
static int stmpe_init_hw(struct stmpe_touch *ts)
{
int ret;
u8 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;
}
ret = stmpe811_adc_common_init(stmpe);
if (ret) {
stmpe_disable(stmpe, STMPE_BLOCK_TOUCHSCREEN | STMPE_BLOCK_ADC);
return ret;
}
tsc_cfg = STMPE_AVE_CTRL(ts->ave_ctrl) |
STMPE_DET_DELAY(ts->touch_det_delay) |
STMPE_SETTLING(ts->settling);
tsc_cfg_mask = STMPE_AVE_CTRL(0xff) | STMPE_DET_DELAY(0xff) |
STMPE_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,
STMPE_FRACTION_Z(0xff), STMPE_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,
STMPE_I_DRIVE(0xff), STMPE_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,
STMPE_OP_MODE(0xff), STMPE_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 void stmpe_ts_get_platform_info(struct platform_device *pdev,
struct stmpe_touch *ts)
{
struct device_node *np = pdev->dev.of_node;
u32 val;
if (np) {
if (!of_property_read_u32(np, "st,sample-time", &val))
ts->stmpe->sample_time = val;
if (!of_property_read_u32(np, "st,mod-12b", &val))
ts->stmpe->mod_12b = val;
if (!of_property_read_u32(np, "st,ref-sel", &val))
ts->stmpe->ref_sel = val;
if (!of_property_read_u32(np, "st,adc-freq", &val))
ts->stmpe->adc_freq = val;
if (!of_property_read_u32(np, "st,ave-ctrl", &val))
ts->ave_ctrl = val;
if (!of_property_read_u32(np, "st,touch-det-delay", &val))
ts->touch_det_delay = val;
if (!of_property_read_u32(np, "st,settling", &val))
ts->settling = val;
if (!of_property_read_u32(np, "st,fraction-z", &val))
ts->fraction_z = val;
if (!of_property_read_u32(np, "st,i-drive", &val))
ts->i_drive = val;
}
}
static int stmpe_input_probe(struct platform_device *pdev)
{
struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
struct stmpe_touch *ts;
struct input_dev *idev;
int error;
int ts_irq;
ts_irq = platform_get_irq_byname(pdev, "FIFO_TH");
if (ts_irq < 0)
return ts_irq;
ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL);
if (!ts)
return -ENOMEM;
idev = devm_input_allocate_device(&pdev->dev);
if (!idev)
return -ENOMEM;
platform_set_drvdata(pdev, ts);
ts->stmpe = stmpe;
ts->idev = idev;
ts->dev = &pdev->dev;
stmpe_ts_get_platform_info(pdev, ts);
INIT_DELAYED_WORK(&ts->work, stmpe_work);
error = devm_request_threaded_irq(&pdev->dev, ts_irq,
NULL, stmpe_ts_handler,
IRQF_ONESHOT, STMPE_TS_NAME, ts);
if (error) {
dev_err(&pdev->dev, "Failed to request IRQ %d\n", ts_irq);
return error;
}
error = stmpe_init_hw(ts);
if (error)
return error;
idev->name = STMPE_TS_NAME;
idev->phys = STMPE_TS_NAME"/input0";
idev->id.bustype = BUS_I2C;
idev->open = stmpe_ts_open;
idev->close = stmpe_ts_close;
input_set_drvdata(idev, ts);
input_set_capability(idev, EV_KEY, BTN_TOUCH);
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);
error = input_register_device(idev);
if (error) {
dev_err(&pdev->dev, "Could not register input device\n");
return error;
}
return 0;
}
static int stmpe_ts_remove(struct platform_device *pdev)
{
struct stmpe_touch *ts = platform_get_drvdata(pdev);
stmpe_disable(ts->stmpe, STMPE_BLOCK_TOUCHSCREEN);
return 0;
}
static struct platform_driver stmpe_ts_driver = {
.driver = {
.name = STMPE_TS_NAME,
},
.probe = stmpe_input_probe,
.remove = stmpe_ts_remove,
};
module_platform_driver(stmpe_ts_driver);
static const struct of_device_id stmpe_ts_ids[] = {
{ .compatible = "st,stmpe-ts", },
{ },
};
MODULE_DEVICE_TABLE(of, stmpe_ts_ids);
MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
MODULE_DESCRIPTION("STMPEXXX touchscreen driver");
MODULE_LICENSE("GPL");
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