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linux/drivers/input/touchscreen/ti_am335x_tsc.c
Linus Torvalds 4937e2a6f9 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 
Pull input updates from Dmitry Torokhov:
 "Updates for the input subsystem.  You will get an new drivers for
  Hyper-V synthetic keyboard and for Neonode zForce touchscreens, plus a
  bunch of driver fixes and cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (49 commits)
  Revert "Input: ALPS - add support for model found on Dell XT2"
  arm: dts: am335x sk: add touchscreen support
  Input: ti_am335x_tsc - fix spelling mistake in TSC/ADC DT binding
  Input: cyttsp4 - replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  Input: mma8450 - add missing i2c_set_clientdata() in mma8450_probe()
  Input: mpu3050 - add missing i2c_set_clientdata() in mpu3050_probe()
  Input: tnetv107x-keypad - make irqs signed for error handling
  Input: add driver for Neonode zForce based touchscreens
  Input: sh_keysc - enable the driver on all ARM platforms
  Input: remove a redundant max() call
  Input: mousedev - allow disabling even without CONFIG_EXPERT
  Input: allow deselecting serio drivers even without CONFIG_EXPERT
  Input: i8042 - add PNP modaliases
  Input: evdev - fall back to vmalloc for client event buffer
  Input: cypress_ps2 - do not consider data bad if palm is detected
  Input: cypress_ps2 - remove useless cast
  Input: fix PWM-related undefined reference errors
  Input: ALPS - change secondary device's name
  Input: wacom - not all multi-interface devices support touch
  Input: nspire-keypad - add missing clk_disable_unprepare() on error path
  ...
2013-11-15 16:43:53 -08:00

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/*
* 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;
u32 step_mask;
};
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;
ts_dev->step_mask = stepenable;
am335x_tsc_se_set(ts_dev->mfd_tscadc, ts_dev->step_mask);
}
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);
/*
* ADC and touchscreen share the IRQ line.
* FIFO1 interrupts are used by ADC. Handle FIFO0 IRQs here only
*/
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_set(ts_dev->mfd_tscadc, ts_dev->step_mask);
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;
/*
* Try with the new binding first. If it fails, try again with
* bogus, miss-spelled version.
*/
err = of_property_read_u32(node, "ti,coordinate-readouts",
&ts_dev->coordinate_readouts);
if (err < 0)
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,
IRQF_SHARED, 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 = 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");
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