/*
* 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/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/sort.h>
#include <linux/pm_wakeirq.h>
#include <linux/mfd/ti_am335x_tscadc.h>
#define ADCFSM_STEPID 0x10
#define SEQ_SETTLE 275
#define MAX_12BIT ((1 << 12) - 1)
#define TSC_IRQENB_MASK (IRQENB_FIFO0THRES | IRQENB_EOS | IRQENB_HW_PEN)
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;
struct device *dev;
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;
u32 charge_delay;
};
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, n;
int end_step, first_step, tsc_steps;
u32 stepenable;
config = STEPCONFIG_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_xp |
STEPCONFIG_INM_ADCREFM;
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;
}
tsc_steps = ts_dev->coordinate_readouts * 2 + 2;
first_step = TOTAL_STEPS - tsc_steps;
/* Steps 16 to 16-coordinate_readouts is for X */
end_step = first_step + tsc_steps;
n = 0;
for (i = end_step - ts_dev->coordinate_readouts; i < end_step; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i),
n++ == 0 ? STEPCONFIG_OPENDLY : 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 |
STEPCONFIG_XNP | STEPCONFIG_YPN;
break;
case 8:
config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);
break;
}
/* 1 ... coordinate_readouts is for Y */
end_step = first_step + ts_dev->coordinate_readouts;
n = 0;
for (i = first_step; i < end_step; i++) {
titsc_writel(ts_dev, REG_STEPCONFIG(i), config);
titsc_writel(ts_dev, REG_STEPDELAY(i),
n++ == 0 ? STEPCONFIG_OPENDLY : 0);
}
/* Make CHARGECONFIG same as IDLECONFIG */
config = titsc_readl(ts_dev, REG_IDLECONFIG);
titsc_writel(ts_dev, REG_CHARGECONFIG, config);
titsc_writel(ts_dev, REG_CHARGEDELAY, ts_dev->charge_delay);
/* coordinate_readouts + 1 ... coordinate_readouts + 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_MODE_HWSYNC |
STEPCONFIG_AVG_16 | ts_dev->bit_yp |
ts_dev->bit_xn | STEPCONFIG_INM_ADCREFM |
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 steps end ... end - readouts * 2 + 2 and bit 0 for TS_Charge */
stepenable = 1;
for (i = 0; i < tsc_steps; i++)
stepenable |= 1 << (first_step + i + 1);
ts_dev->step_mask = stepenable;
am335x_tsc_se_set_cache(ts_dev->mfd_tscadc, ts_dev->step_mask);
}
static int titsc_cmp_coord(const void *a, const void *b)
{
return *(int *)a - *(int *)b;
}
static void titsc_read_coordinates(struct titsc *ts_dev,
u32 *x, u32 *y, u32 *z1, u32 *z2)
{
unsigned int yvals[7], xvals[7];
unsigned int i, xsum = 0, ysum = 0;
unsigned int creads = ts_dev->coordinate_readouts;
for (i = 0; i < creads; i++) {
yvals[i] = titsc_readl(ts_dev, REG_FIFO0);
yvals[i] &= 0xfff;
}
*z1 = titsc_readl(ts_dev, REG_FIFO0);
*z1 &= 0xfff;
*z2 = titsc_readl(ts_dev, REG_FIFO0);
*z2 &= 0xfff;
for (i = 0; i < creads; i++) {
xvals[i] = titsc_readl(ts_dev, REG_FIFO0);
xvals[i] &= 0xfff;
}
/*
* If co-ordinates readouts is less than 4 then
* report the average. In case of 4 or more
* readouts, sort the co-ordinate samples, drop
* min and max values and report the average of
* remaining values.
*/
if (creads <= 3) {
for (i = 0; i < creads; i++) {
ysum += yvals[i];
xsum += xvals[i];
}
ysum /= creads;
xsum /= creads;
} else {
sort(yvals, creads, sizeof(unsigned int),
titsc_cmp_coord, NULL);
sort(xvals, creads, sizeof(unsigned int),
titsc_cmp_coord, NULL);
for (i = 1; i < creads - 1; i++) {
ysum += yvals[i];
xsum += xvals[i];
}
ysum /= creads - 2;
xsum /= creads - 2;
}
*y = ysum;
*x = xsum;
}
static irqreturn_t titsc_irq(int irq, void *dev)
{
struct titsc *ts_dev = dev;
struct input_dev *input_dev = ts_dev->input;
unsigned int fsm, status, irqclr = 0;
unsigned int x = 0, y = 0;
unsigned int z1, z2, z;
status = titsc_readl(ts_dev, REG_RAWIRQSTATUS);
if (status & IRQENB_HW_PEN) {
ts_dev->pen_down = true;
irqclr |= IRQENB_HW_PEN;
pm_stay_awake(ts_dev->dev);
}
if (status & IRQENB_PENUP) {
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);
pm_relax(ts_dev->dev);
} else {
ts_dev->pen_down = true;
}
irqclr |= IRQENB_PENUP;
}
if (status & IRQENB_EOS)
irqclr |= IRQENB_EOS;
/*
* 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 position/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;
}
if (irqclr) {
titsc_writel(ts_dev, REG_IRQSTATUS, irqclr);
if (status & IRQENB_EOS)
am335x_tsc_se_set_cache(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) {
dev_warn(&pdev->dev, "please use 'ti,coordinate-readouts' instead\n");
err = of_property_read_u32(node, "ti,coordiante-readouts",
&ts_dev->coordinate_readouts);
}
if (err < 0)
return err;
if (ts_dev->coordinate_readouts <= 0) {
dev_warn(&pdev->dev,
"invalid co-ordinate readouts, resetting it to 5\n");
ts_dev->coordinate_readouts = 5;
}
err = of_property_read_u32(node, "ti,charge-delay",
&ts_dev->charge_delay);
/*
* If ti,charge-delay value is not specified, then use
* CHARGEDLY_OPENDLY as the default value.
*/
if (err < 0) {
ts_dev->charge_delay = CHARGEDLY_OPENDLY;
dev_warn(&pdev->dev, "ti,charge-delay not specified\n");
}
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(*ts_dev), 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;
ts_dev->dev = &pdev->dev;
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;
}
device_init_wakeup(&pdev->dev, true);
err = dev_pm_set_wake_irq(&pdev->dev, ts_dev->irq);
if (err)
dev_err(&pdev->dev, "irq wake enable failed.\n");
titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_FIFO0THRES);
titsc_writel(ts_dev, REG_IRQENABLE, IRQENB_EOS);
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:
dev_pm_clear_wake_irq(&pdev->dev);
device_init_wakeup(&pdev->dev, false);
free_irq(ts_dev->irq, ts_dev);
err_free_mem:
input_free_device(input_dev);
kfree(ts_dev);
return err;
}
static void titsc_remove(struct platform_device *pdev)
{
struct titsc *ts_dev = platform_get_drvdata(pdev);
u32 steps;
dev_pm_clear_wake_irq(&pdev->dev);
device_init_wakeup(&pdev->dev, false);
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);
}
static int titsc_suspend(struct device *dev)
{
struct titsc *ts_dev = dev_get_drvdata(dev);
unsigned int idle;
if (device_may_wakeup(dev)) {
titsc_writel(ts_dev, REG_IRQSTATUS, TSC_IRQENB_MASK);
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);
if (device_may_wakeup(dev)) {
titsc_writel(ts_dev, REG_IRQWAKEUP,
0x00);
titsc_writel(ts_dev, REG_IRQCLR, IRQENB_HW_PEN);
pm_relax(dev);
}
titsc_step_config(ts_dev);
titsc_writel(ts_dev, REG_FIFO0THR,
ts_dev->coordinate_readouts * 2 + 2 - 1);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(titsc_pm_ops, titsc_suspend, titsc_resume);
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_new = titsc_remove,
.driver = {
.name = "TI-am335x-tsc",
.pm = pm_sleep_ptr(&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 <[email protected]>");
MODULE_LICENSE("GPL");
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