516 строки
13 KiB
C
516 строки
13 KiB
C
/*
|
|
* TI Touch Screen driver
|
|
*
|
|
* Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
|
|
*
|
|
* 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 version 2.
|
|
*
|
|
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
|
|
* kind, whether express or implied; without even the implied warranty
|
|
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/err.h>
|
|
#include <linux/module.h>
|
|
#include <linux/input.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/io.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
|
|
#include <linux/mfd/ti_am335x_tscadc.h>
|
|
|
|
#define ADCFSM_STEPID 0x10
|
|
#define SEQ_SETTLE 275
|
|
#define MAX_12BIT ((1 << 12) - 1)
|
|
|
|
static const int config_pins[] = {
|
|
STEPCONFIG_XPP,
|
|
STEPCONFIG_XNN,
|
|
STEPCONFIG_YPP,
|
|
STEPCONFIG_YNN,
|
|
};
|
|
|
|
struct titsc {
|
|
struct input_dev *input;
|
|
struct ti_tscadc_dev *mfd_tscadc;
|
|
unsigned int irq;
|
|
unsigned int wires;
|
|
unsigned int x_plate_resistance;
|
|
bool pen_down;
|
|
int coordinate_readouts;
|
|
u32 config_inp[4];
|
|
u32 bit_xp, bit_xn, bit_yp, bit_yn;
|
|
u32 inp_xp, inp_xn, inp_yp, inp_yn;
|
|
};
|
|
|
|
static unsigned int titsc_readl(struct titsc *ts, unsigned int reg)
|
|
{
|
|
return readl(ts->mfd_tscadc->tscadc_base + reg);
|
|
}
|
|
|
|
static void titsc_writel(struct titsc *tsc, unsigned int reg,
|
|
unsigned int val)
|
|
{
|
|
writel(val, tsc->mfd_tscadc->tscadc_base + reg);
|
|
}
|
|
|
|
static int titsc_config_wires(struct titsc *ts_dev)
|
|
{
|
|
u32 analog_line[4];
|
|
u32 wire_order[4];
|
|
int i, bit_cfg;
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
/*
|
|
* Get the order in which TSC wires are attached
|
|
* w.r.t. each of the analog input lines on the EVM.
|
|
*/
|
|
analog_line[i] = (ts_dev->config_inp[i] & 0xF0) >> 4;
|
|
wire_order[i] = ts_dev->config_inp[i] & 0x0F;
|
|
if (WARN_ON(analog_line[i] > 7))
|
|
return -EINVAL;
|
|
if (WARN_ON(wire_order[i] > ARRAY_SIZE(config_pins)))
|
|
return -EINVAL;
|
|
}
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
int an_line;
|
|
int wi_order;
|
|
|
|
an_line = analog_line[i];
|
|
wi_order = wire_order[i];
|
|
bit_cfg = config_pins[wi_order];
|
|
if (bit_cfg == 0)
|
|
return -EINVAL;
|
|
switch (wi_order) {
|
|
case 0:
|
|
ts_dev->bit_xp = bit_cfg;
|
|
ts_dev->inp_xp = an_line;
|
|
break;
|
|
|
|
case 1:
|
|
ts_dev->bit_xn = bit_cfg;
|
|
ts_dev->inp_xn = an_line;
|
|
break;
|
|
|
|
case 2:
|
|
ts_dev->bit_yp = bit_cfg;
|
|
ts_dev->inp_yp = an_line;
|
|
break;
|
|
case 3:
|
|
ts_dev->bit_yn = bit_cfg;
|
|
ts_dev->inp_yn = an_line;
|
|
break;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void titsc_step_config(struct titsc *ts_dev)
|
|
{
|
|
unsigned int config;
|
|
int i;
|
|
int end_step;
|
|
u32 stepenable;
|
|
|
|
config = STEPCONFIG_MODE_HWSYNC |
|
|
STEPCONFIG_AVG_16 | ts_dev->bit_xp;
|
|
switch (ts_dev->wires) {
|
|
case 4:
|
|
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
|
|
break;
|
|
case 5:
|
|
config |= ts_dev->bit_yn |
|
|
STEPCONFIG_INP_AN4 | ts_dev->bit_xn |
|
|
ts_dev->bit_yp;
|
|
break;
|
|
case 8:
|
|
config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;
|
|
break;
|
|
}
|
|
|
|
/* 1 … coordinate_readouts is for X */
|
|
end_step = ts_dev->coordinate_readouts;
|
|
for (i = 0; i < end_step; i++) {
|
|
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
|
|
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
|
|
}
|
|
|
|
config = 0;
|
|
config = STEPCONFIG_MODE_HWSYNC |
|
|
STEPCONFIG_AVG_16 | ts_dev->bit_yn |
|
|
STEPCONFIG_INM_ADCREFM;
|
|
switch (ts_dev->wires) {
|
|
case 4:
|
|
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
|
|
break;
|
|
case 5:
|
|
config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
|
|
ts_dev->bit_xn | ts_dev->bit_yp;
|
|
break;
|
|
case 8:
|
|
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
|
|
break;
|
|
}
|
|
|
|
/* coordinate_readouts … coordinate_readouts * 2 is for Y */
|
|
end_step = ts_dev->coordinate_readouts * 2;
|
|
for (i = ts_dev->coordinate_readouts; i < end_step; i++) {
|
|
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
|
|
titsc_writel(ts_dev, REG_STEPDELAY(i), STEPCONFIG_OPENDLY);
|
|
}
|
|
|
|
/* Charge step configuration */
|
|
config = ts_dev->bit_xp | ts_dev->bit_yn |
|
|
STEPCHARGE_RFP_XPUL | STEPCHARGE_RFM_XNUR |
|
|
STEPCHARGE_INM_AN1 | STEPCHARGE_INP(ts_dev->inp_yp);
|
|
|
|
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
|
|
titsc_writel(ts_dev, REG_CHARGEDELAY, CHARGEDLY_OPENDLY);
|
|
|
|
/* coordinate_readouts * 2 … coordinate_readouts * 2 + 2 is for Z */
|
|
config = STEPCONFIG_MODE_HWSYNC |
|
|
STEPCONFIG_AVG_16 | ts_dev->bit_yp |
|
|
ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
|
|
STEPCONFIG_INP(ts_dev->inp_xp);
|
|
titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
|
|
titsc_writel(ts_dev, REG_STEPDELAY(end_step),
|
|
STEPCONFIG_OPENDLY);
|
|
|
|
end_step++;
|
|
config |= STEPCONFIG_INP(ts_dev->inp_yn);
|
|
titsc_writel(ts_dev, REG_STEPCONFIG(end_step), config);
|
|
titsc_writel(ts_dev, REG_STEPDELAY(end_step),
|
|
STEPCONFIG_OPENDLY);
|
|
|
|
/* The steps1 … end and bit 0 for TS_Charge */
|
|
stepenable = (1 << (end_step + 2)) - 1;
|
|
am335x_tsc_se_set(ts_dev->mfd_tscadc, stepenable);
|
|
}
|
|
|
|
static void titsc_read_coordinates(struct titsc *ts_dev,
|
|
u32 *x, u32 *y, u32 *z1, u32 *z2)
|
|
{
|
|
unsigned int fifocount = titsc_readl(ts_dev, REG_FIFO0CNT);
|
|
unsigned int prev_val_x = ~0, prev_val_y = ~0;
|
|
unsigned int prev_diff_x = ~0, prev_diff_y = ~0;
|
|
unsigned int read, diff;
|
|
unsigned int i, channel;
|
|
unsigned int creads = ts_dev->coordinate_readouts;
|
|
|
|
*z1 = *z2 = 0;
|
|
if (fifocount % (creads * 2 + 2))
|
|
fifocount -= fifocount % (creads * 2 + 2);
|
|
/*
|
|
* Delta filter is used to remove large variations in sampled
|
|
* values from ADC. The filter tries to predict where the next
|
|
* coordinate could be. This is done by taking a previous
|
|
* coordinate and subtracting it form current one. Further the
|
|
* algorithm compares the difference with that of a present value,
|
|
* if true the value is reported to the sub system.
|
|
*/
|
|
for (i = 0; i < fifocount; i++) {
|
|
read = titsc_readl(ts_dev, REG_FIFO0);
|
|
|
|
channel = (read & 0xf0000) >> 16;
|
|
read &= 0xfff;
|
|
if (channel < creads) {
|
|
diff = abs(read - prev_val_x);
|
|
if (diff < prev_diff_x) {
|
|
prev_diff_x = diff;
|
|
*x = read;
|
|
}
|
|
prev_val_x = read;
|
|
|
|
} else if (channel < creads * 2) {
|
|
diff = abs(read - prev_val_y);
|
|
if (diff < prev_diff_y) {
|
|
prev_diff_y = diff;
|
|
*y = read;
|
|
}
|
|
prev_val_y = read;
|
|
|
|
} else if (channel < creads * 2 + 1) {
|
|
*z1 = read;
|
|
|
|
} else if (channel < creads * 2 + 2) {
|
|
*z2 = read;
|
|
}
|
|
}
|
|
}
|
|
|
|
static irqreturn_t titsc_irq(int irq, void *dev)
|
|
{
|
|
struct titsc *ts_dev = dev;
|
|
struct input_dev *input_dev = ts_dev->input;
|
|
unsigned int status, irqclr = 0;
|
|
unsigned int x = 0, y = 0;
|
|
unsigned int z1, z2, z;
|
|
unsigned int fsm;
|
|
|
|
status = titsc_readl(ts_dev, REG_IRQSTATUS);
|
|
if (status & IRQENB_FIFO0THRES) {
|
|
|
|
titsc_read_coordinates(ts_dev, &x, &y, &z1, &z2);
|
|
|
|
if (ts_dev->pen_down && z1 != 0 && z2 != 0) {
|
|
/*
|
|
* Calculate pressure using formula
|
|
* Resistance(touch) = x plate resistance *
|
|
* x postion/4096 * ((z2 / z1) - 1)
|
|
*/
|
|
z = z1 - z2;
|
|
z *= x;
|
|
z *= ts_dev->x_plate_resistance;
|
|
z /= z2;
|
|
z = (z + 2047) >> 12;
|
|
|
|
if (z <= MAX_12BIT) {
|
|
input_report_abs(input_dev, ABS_X, x);
|
|
input_report_abs(input_dev, ABS_Y, y);
|
|
input_report_abs(input_dev, ABS_PRESSURE, z);
|
|
input_report_key(input_dev, BTN_TOUCH, 1);
|
|
input_sync(input_dev);
|
|
}
|
|
}
|
|
irqclr |= IRQENB_FIFO0THRES;
|
|
}
|
|
|
|
/*
|
|
* Time for sequencer to settle, to read
|
|
* correct state of the sequencer.
|
|
*/
|
|
udelay(SEQ_SETTLE);
|
|
|
|
status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
|
|
if (status & IRQENB_PENUP) {
|
|
/* Pen up event */
|
|
fsm = titsc_readl(ts_dev, REG_ADCFSM);
|
|
if (fsm == ADCFSM_STEPID) {
|
|
ts_dev->pen_down = false;
|
|
input_report_key(input_dev, BTN_TOUCH, 0);
|
|
input_report_abs(input_dev, ABS_PRESSURE, 0);
|
|
input_sync(input_dev);
|
|
} else {
|
|
ts_dev->pen_down = true;
|
|
}
|
|
irqclr |= IRQENB_PENUP;
|
|
}
|
|
|
|
if (status & IRQENB_HW_PEN) {
|
|
|
|
titsc_writel(ts_dev, REG_IRQWAKEUP, 0x00);
|
|
titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
|
|
}
|
|
|
|
if (irqclr) {
|
|
titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
|
|
am335x_tsc_se_update(ts_dev->mfd_tscadc);
|
|
return IRQ_HANDLED;
|
|
}
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
static int titsc_parse_dt(struct platform_device *pdev,
|
|
struct titsc *ts_dev)
|
|
{
|
|
struct device_node *node = pdev->dev.of_node;
|
|
int err;
|
|
|
|
if (!node)
|
|
return -EINVAL;
|
|
|
|
err = of_property_read_u32(node, "ti,wires", &ts_dev->wires);
|
|
if (err < 0)
|
|
return err;
|
|
switch (ts_dev->wires) {
|
|
case 4:
|
|
case 5:
|
|
case 8:
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
err = of_property_read_u32(node, "ti,x-plate-resistance",
|
|
&ts_dev->x_plate_resistance);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
err = of_property_read_u32(node, "ti,coordiante-readouts",
|
|
&ts_dev->coordinate_readouts);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
return of_property_read_u32_array(node, "ti,wire-config",
|
|
ts_dev->config_inp, ARRAY_SIZE(ts_dev->config_inp));
|
|
}
|
|
|
|
/*
|
|
* The functions for inserting/removing driver as a module.
|
|
*/
|
|
|
|
static int titsc_probe(struct platform_device *pdev)
|
|
{
|
|
struct titsc *ts_dev;
|
|
struct input_dev *input_dev;
|
|
struct ti_tscadc_dev *tscadc_dev = ti_tscadc_dev_get(pdev);
|
|
int err;
|
|
|
|
/* Allocate memory for device */
|
|
ts_dev = kzalloc(sizeof(struct titsc), GFP_KERNEL);
|
|
input_dev = input_allocate_device();
|
|
if (!ts_dev || !input_dev) {
|
|
dev_err(&pdev->dev, "failed to allocate memory.\n");
|
|
err = -ENOMEM;
|
|
goto err_free_mem;
|
|
}
|
|
|
|
tscadc_dev->tsc = ts_dev;
|
|
ts_dev->mfd_tscadc = tscadc_dev;
|
|
ts_dev->input = input_dev;
|
|
ts_dev->irq = tscadc_dev->irq;
|
|
|
|
err = titsc_parse_dt(pdev, ts_dev);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "Could not find valid DT data.\n");
|
|
goto err_free_mem;
|
|
}
|
|
|
|
err = request_irq(ts_dev->irq, titsc_irq,
|
|
0, pdev->dev.driver->name, ts_dev);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "failed to allocate irq.\n");
|
|
goto err_free_mem;
|
|
}
|
|
|
|
titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
|
|
err = titsc_config_wires(ts_dev);
|
|
if (err) {
|
|
dev_err(&pdev->dev, "wrong i/p wire configuration\n");
|
|
goto err_free_irq;
|
|
}
|
|
titsc_step_config(ts_dev);
|
|
titsc_writel(ts_dev, REG_FIFO0THR,
|
|
ts_dev->coordinate_readouts * 2 + 2 - 1);
|
|
|
|
input_dev->name = "ti-tsc";
|
|
input_dev->dev.parent = &pdev->dev;
|
|
|
|
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, 0, 0);
|
|
input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
|
|
input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
|
|
|
|
/* register to the input system */
|
|
err = input_register_device(input_dev);
|
|
if (err)
|
|
goto err_free_irq;
|
|
|
|
platform_set_drvdata(pdev, ts_dev);
|
|
return 0;
|
|
|
|
err_free_irq:
|
|
free_irq(ts_dev->irq, ts_dev);
|
|
err_free_mem:
|
|
input_free_device(input_dev);
|
|
kfree(ts_dev);
|
|
return err;
|
|
}
|
|
|
|
static int titsc_remove(struct platform_device *pdev)
|
|
{
|
|
struct titsc *ts_dev = platform_get_drvdata(pdev);
|
|
u32 steps;
|
|
|
|
free_irq(ts_dev->irq, ts_dev);
|
|
|
|
/* total steps followed by the enable mask */
|
|
steps = 2 * ts_dev->coordinate_readouts + 2;
|
|
steps = (1 << steps) - 1;
|
|
am335x_tsc_se_clr(ts_dev->mfd_tscadc, steps);
|
|
|
|
input_unregister_device(ts_dev->input);
|
|
|
|
kfree(ts_dev);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int titsc_suspend(struct device *dev)
|
|
{
|
|
struct titsc *ts_dev = dev_get_drvdata(dev);
|
|
struct ti_tscadc_dev *tscadc_dev;
|
|
unsigned int idle;
|
|
|
|
tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
|
|
if (device_may_wakeup(tscadc_dev->dev)) {
|
|
idle = titsc_readl(ts_dev, REG_IRQENABLE);
|
|
titsc_writel(ts_dev, REG_IRQENABLE,
|
|
(idle | IRQENB_HW_PEN));
|
|
titsc_writel(ts_dev, REG_IRQWAKEUP, IRQWKUP_ENB);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int titsc_resume(struct device *dev)
|
|
{
|
|
struct titsc *ts_dev = dev_get_drvdata(dev);
|
|
struct ti_tscadc_dev *tscadc_dev;
|
|
|
|
tscadc_dev = ti_tscadc_dev_get(to_platform_device(dev));
|
|
if (device_may_wakeup(tscadc_dev->dev)) {
|
|
titsc_writel(ts_dev, REG_IRQWAKEUP,
|
|
0x00);
|
|
titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
|
|
}
|
|
titsc_step_config(ts_dev);
|
|
titsc_writel(ts_dev, REG_FIFO0THR,
|
|
ts_dev->coordinate_readouts * 2 + 2 - 1);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops titsc_pm_ops = {
|
|
.suspend = titsc_suspend,
|
|
.resume = titsc_resume,
|
|
};
|
|
#define TITSC_PM_OPS (&titsc_pm_ops)
|
|
#else
|
|
#define TITSC_PM_OPS NULL
|
|
#endif
|
|
|
|
static const struct of_device_id ti_tsc_dt_ids[] = {
|
|
{ .compatible = "ti,am3359-tsc", },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ti_tsc_dt_ids);
|
|
|
|
static struct platform_driver ti_tsc_driver = {
|
|
.probe = titsc_probe,
|
|
.remove = titsc_remove,
|
|
.driver = {
|
|
.name = "TI-am335x-tsc",
|
|
.owner = THIS_MODULE,
|
|
.pm = TITSC_PM_OPS,
|
|
.of_match_table = of_match_ptr(ti_tsc_dt_ids),
|
|
},
|
|
};
|
|
module_platform_driver(ti_tsc_driver);
|
|
|
|
MODULE_DESCRIPTION("TI touchscreen controller driver");
|
|
MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
|
|
MODULE_LICENSE("GPL");
|