- 根目录:
- drivers
- input
- touchscreen
- tsc2007.c
/*
* drivers/input/touchscreen/tsc2007.c
*
* Copyright (c) 2008 MtekVision Co., Ltd.
* Kwangwoo Lee <kwlee@mtekvision.com>
*
* Using code from:
* - ads7846.c
* Copyright (c) 2005 David Brownell
* Copyright (c) 2006 Nokia Corporation
* - corgi_ts.c
* Copyright (C) 2004-2005 Richard Purdie
* - omap_ts.[hc], ads7846.h, ts_osk.c
* Copyright (C) 2002 MontaVista Software
* Copyright (C) 2004 Texas Instruments
* Copyright (C) 2005 Dirk Behme
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/i2c/tsc2007.h>
#include <linux/of_device.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#define TSC2007_MEASURE_TEMP0 (0x0 << 4)
#define TSC2007_MEASURE_AUX (0x2 << 4)
#define TSC2007_MEASURE_TEMP1 (0x4 << 4)
#define TSC2007_ACTIVATE_XN (0x8 << 4)
#define TSC2007_ACTIVATE_YN (0x9 << 4)
#define TSC2007_ACTIVATE_YP_XN (0xa << 4)
#define TSC2007_SETUP (0xb << 4)
#define TSC2007_MEASURE_X (0xc << 4)
#define TSC2007_MEASURE_Y (0xd << 4)
#define TSC2007_MEASURE_Z1 (0xe << 4)
#define TSC2007_MEASURE_Z2 (0xf << 4)
#define TSC2007_POWER_OFF_IRQ_EN (0x0 << 2)
#define TSC2007_ADC_ON_IRQ_DIS0 (0x1 << 2)
#define TSC2007_ADC_OFF_IRQ_EN (0x2 << 2)
#define TSC2007_ADC_ON_IRQ_DIS1 (0x3 << 2)
#define TSC2007_12BIT (0x0 << 1)
#define TSC2007_8BIT (0x1 << 1)
#define MAX_12BIT ((1 << 12) - 1)
#define ADC_ON_12BIT (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
#define READ_Y (ADC_ON_12BIT | TSC2007_MEASURE_Y)
#define READ_Z1 (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
#define READ_Z2 (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
#define READ_X (ADC_ON_12BIT | TSC2007_MEASURE_X)
#define PWRDOWN (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
struct ts_event {
u16 x;
u16 y;
u16 z1, z2;
};
struct tsc2007 {
struct input_dev *input;
char phys[32];
struct i2c_client *client;
u16 model;
u16 x_plate_ohms;
u16 max_rt;
unsigned long poll_period;
int fuzzx;
int fuzzy;
int fuzzz;
unsigned gpio;
int irq;
wait_queue_head_t wait;
bool stopped;
int (*get_pendown_state)(struct device *);
void (*clear_penirq)(void);
};
static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
{
s32 data;
u16 val;
data = i2c_smbus_read_word_data(tsc->client, cmd);
if (data < 0) {
dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
return data;
}
/* The protocol and raw data format from i2c interface:
* S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
* Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
*/
val = swab16(data) >> 4;
dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
return val;
}
static void tsc2007_read_values(struct tsc2007 *tsc, struct ts_event *tc)
{
/* y- still on; turn on only y+ (and ADC) */
tc->y = tsc2007_xfer(tsc, READ_Y);
/* turn y- off, x+ on, then leave in lowpower */
tc->x = tsc2007_xfer(tsc, READ_X);
/* turn y+ off, x- on; we'll use formula #1 */
tc->z1 = tsc2007_xfer(tsc, READ_Z1);
tc->z2 = tsc2007_xfer(tsc, READ_Z2);
/* Prepare for next touch reading - power down ADC, enable PENIRQ */
tsc2007_xfer(tsc, PWRDOWN);
}
static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
{
u32 rt = 0;
/* range filtering */
if (tc->x == MAX_12BIT)
tc->x = 0;
if (likely(tc->x && tc->z1)) {
/* compute touch pressure resistance using equation #1 */
rt = tc->z2 - tc->z1;
rt *= tc->x;
rt *= tsc->x_plate_ohms;
rt /= tc->z1;
rt = (rt + 2047) >> 12;
}
return rt;
}
static bool tsc2007_is_pen_down(struct tsc2007 *ts)
{
/*
* NOTE: We can't rely on the pressure to determine the pen down
* state, even though this controller has a pressure sensor.
* The pressure value can fluctuate for quite a while after
* lifting the pen and in some cases may not even settle at the
* expected value.
*
* The only safe way to check for the pen up condition is in the
* work function by reading the pen signal state (it's a GPIO
* and IRQ). Unfortunately such callback is not always available,
* in that case we assume that the pen is down and expect caller
* to fall back on the pressure reading.
*/
if (!ts->get_pendown_state)
return true;
return ts->get_pendown_state(&ts->client->dev);
}
static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;
struct input_dev *input = ts->input;
struct ts_event tc;
u32 rt;
while (!ts->stopped && tsc2007_is_pen_down(ts)) {
/* pen is down, continue with the measurement */
tsc2007_read_values(ts, &tc);
rt = tsc2007_calculate_pressure(ts, &tc);
if (!rt && !ts->get_pendown_state) {
/*
* If pressure reported is 0 and we don't have
* callback to check pendown state, we have to
* assume that pen was lifted up.
*/
break;
}
if (rt <= ts->max_rt) {
dev_dbg(&ts->client->dev,
"DOWN point(%4d,%4d), pressure (%4u)\n",
tc.x, tc.y, rt);
input_report_key(input, BTN_TOUCH, 1);
input_report_abs(input, ABS_X, tc.x);
input_report_abs(input, ABS_Y, tc.y);
input_report_abs(input, ABS_PRESSURE, rt);
input_sync(input);
} else {
/*
* Sample found inconsistent by debouncing or pressure is
* beyond the maximum. Don't report it to user space,
* repeat at least once more the measurement.
*/
dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
}
wait_event_timeout(ts->wait, ts->stopped,
msecs_to_jiffies(ts->poll_period));
}
dev_dbg(&ts->client->dev, "UP\n");
input_report_key(input, BTN_TOUCH, 0);
input_report_abs(input, ABS_PRESSURE, 0);
input_sync(input);
if (ts->clear_penirq)
ts->clear_penirq();
return IRQ_HANDLED;
}
static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;
if (tsc2007_is_pen_down(ts))
return IRQ_WAKE_THREAD;
if (ts->clear_penirq)
ts->clear_penirq();
return IRQ_HANDLED;
}
static void tsc2007_stop(struct tsc2007 *ts)
{
ts->stopped = true;
mb();
wake_up(&ts->wait);
disable_irq(ts->irq);
}
static int tsc2007_open(struct input_dev *input_dev)
{
struct tsc2007 *ts = input_get_drvdata(input_dev);
int err;
ts->stopped = false;
mb();
enable_irq(ts->irq);
/* Prepare for touch readings - power down ADC and enable PENIRQ */
err = tsc2007_xfer(ts, PWRDOWN);
if (err < 0) {
tsc2007_stop(ts);
return err;
}
return 0;
}
static void tsc2007_close(struct input_dev *input_dev)
{
struct tsc2007 *ts = input_get_drvdata(input_dev);
tsc2007_stop(ts);
}
#ifdef CONFIG_OF
static int tsc2007_get_pendown_state_gpio(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
struct tsc2007 *ts = i2c_get_clientdata(client);
return !gpio_get_value(ts->gpio);
}
static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
{
struct device_node *np = client->dev.of_node;
u32 val32;
u64 val64;
if (!np) {
dev_err(&client->dev, "missing device tree data\n");
return -EINVAL;
}
if (!of_property_read_u32(np, "ti,max-rt", &val32))
ts->max_rt = val32;
else
ts->max_rt = MAX_12BIT;
if (!of_property_read_u32(np, "ti,fuzzx", &val32))
ts->fuzzx = val32;
if (!of_property_read_u32(np, "ti,fuzzy", &val32))
ts->fuzzy = val32;
if (!of_property_read_u32(np, "ti,fuzzz", &val32))
ts->fuzzz = val32;
if (!of_property_read_u64(np, "ti,poll-period", &val64))
ts->poll_period = val64;
else
ts->poll_period = 1;
if (!of_property_read_u32(np, "ti,x-plate-ohms", &val32)) {
ts->x_plate_ohms = val32;
} else {
dev_err(&client->dev, "missing ti,x-plate-ohms devicetree property.");
return -EINVAL;
}
ts->gpio = of_get_gpio(np, 0);
if (gpio_is_valid(ts->gpio))
ts->get_pendown_state = tsc2007_get_pendown_state_gpio;
else
dev_warn(&client->dev,
"GPIO not specified in DT (of_get_gpio returned %d)\n",
ts->gpio);
return 0;
}
#else
static int tsc2007_probe_dt(struct i2c_client *client, struct tsc2007 *ts)
{
dev_err(&client->dev, "platform data is required!\n");
return -EINVAL;
}
#endif
static int tsc2007_probe_pdev(struct i2c_client *client, struct tsc2007 *ts,
const struct tsc2007_platform_data *pdata,
const struct i2c_device_id *id)
{
ts->model = pdata->model;
ts->x_plate_ohms = pdata->x_plate_ohms;
ts->max_rt = pdata->max_rt ? : MAX_12BIT;
ts->poll_period = pdata->poll_period ? : 1;
ts->get_pendown_state = pdata->get_pendown_state;
ts->clear_penirq = pdata->clear_penirq;
ts->fuzzx = pdata->fuzzx;
ts->fuzzy = pdata->fuzzy;
ts->fuzzz = pdata->fuzzz;
if (pdata->x_plate_ohms == 0) {
dev_err(&client->dev, "x_plate_ohms is not set up in platform data");
return -EINVAL;
}
return 0;
}
static void tsc2007_call_exit_platform_hw(void *data)
{
struct device *dev = data;
const struct tsc2007_platform_data *pdata = dev_get_platdata(dev);
pdata->exit_platform_hw();
}
static int tsc2007_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
const struct tsc2007_platform_data *pdata = dev_get_platdata(&client->dev);
struct tsc2007 *ts;
struct input_dev *input_dev;
int err;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_WORD_DATA))
return -EIO;
ts = devm_kzalloc(&client->dev, sizeof(struct tsc2007), GFP_KERNEL);
if (!ts)
return -ENOMEM;
if (pdata)
err = tsc2007_probe_pdev(client, ts, pdata, id);
else
err = tsc2007_probe_dt(client, ts);
if (err)
return err;
input_dev = devm_input_allocate_device(&client->dev);
if (!input_dev)
return -ENOMEM;
i2c_set_clientdata(client, ts);
ts->client = client;
ts->irq = client->irq;
ts->input = input_dev;
init_waitqueue_head(&ts->wait);
snprintf(ts->phys, sizeof(ts->phys),
"%s/input0", dev_name(&client->dev));
input_dev->name = "TSC2007 Touchscreen";
input_dev->phys = ts->phys;
input_dev->id.bustype = BUS_I2C;
input_dev->open = tsc2007_open;
input_dev->close = tsc2007_close;
input_set_drvdata(input_dev, ts);
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, ts->fuzzx, 0);
input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, ts->fuzzy, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT,
ts->fuzzz, 0);
if (pdata) {
if (pdata->exit_platform_hw) {
err = devm_add_action(&client->dev,
tsc2007_call_exit_platform_hw,
&client->dev);
if (err) {
dev_err(&client->dev,
"Failed to register exit_platform_hw action, %d\n",
err);
return err;
}
}
if (pdata->init_platform_hw)
pdata->init_platform_hw();
}
err = devm_request_threaded_irq(&client->dev, ts->irq,
tsc2007_hard_irq, tsc2007_soft_irq,
IRQF_ONESHOT,
client->dev.driver->name, ts);
if (err) {
dev_err(&client->dev, "Failed to request irq %d: %d\n",
ts->irq, err);
return err;
}
tsc2007_stop(ts);
err = input_register_device(input_dev);
if (err) {
dev_err(&client->dev,
"Failed to register input device: %d\n", err);
return err;
}
return 0;
}
static const struct i2c_device_id tsc2007_idtable[] = {
{ "tsc2007", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
#ifdef CONFIG_OF
static const struct of_device_id tsc2007_of_match[] = {
{ .compatible = "ti,tsc2007" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tsc2007_of_match);
#endif
static struct i2c_driver tsc2007_driver = {
.driver = {
.owner = THIS_MODULE,
.name = "tsc2007",
.of_match_table = of_match_ptr(tsc2007_of_match),
},
.id_table = tsc2007_idtable,
.probe = tsc2007_probe,
};
module_i2c_driver(tsc2007_driver);
MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
MODULE_LICENSE("GPL");