linux/drivers/input/touchscreen/tnetv107x-ts.c

385 lines
9.2 KiB
C

/*
* Texas Instruments TNETV107X Touchscreen Driver
*
* Copyright (C) 2010 Texas Instruments
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/ctype.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <mach/tnetv107x.h>
#define TSC_PENUP_POLL (HZ / 5)
#define IDLE_TIMEOUT 100 /* msec */
/*
* The first and last samples of a touch interval are usually garbage and need
* to be filtered out with these devices. The following definitions control
* the number of samples skipped.
*/
#define TSC_HEAD_SKIP 1
#define TSC_TAIL_SKIP 1
#define TSC_SKIP (TSC_HEAD_SKIP + TSC_TAIL_SKIP + 1)
#define TSC_SAMPLES (TSC_SKIP + 1)
/* Register Offsets */
struct tsc_regs {
u32 rev;
u32 tscm;
u32 bwcm;
u32 swc;
u32 adcchnl;
u32 adcdata;
u32 chval[4];
};
/* TSC Mode Configuration Register (tscm) bits */
#define WMODE BIT(0)
#define TSKIND BIT(1)
#define ZMEASURE_EN BIT(2)
#define IDLE BIT(3)
#define TSC_EN BIT(4)
#define STOP BIT(5)
#define ONE_SHOT BIT(6)
#define SINGLE BIT(7)
#define AVG BIT(8)
#define AVGNUM(x) (((x) & 0x03) << 9)
#define PVSTC(x) (((x) & 0x07) << 11)
#define PON BIT(14)
#define PONBG BIT(15)
#define AFERST BIT(16)
/* ADC DATA Capture Register bits */
#define DATA_VALID BIT(16)
/* Register Access Macros */
#define tsc_read(ts, reg) __raw_readl(&(ts)->regs->reg)
#define tsc_write(ts, reg, val) __raw_writel(val, &(ts)->regs->reg);
#define tsc_set_bits(ts, reg, val) \
tsc_write(ts, reg, tsc_read(ts, reg) | (val))
#define tsc_clr_bits(ts, reg, val) \
tsc_write(ts, reg, tsc_read(ts, reg) & ~(val))
struct sample {
int x, y, p;
};
struct tsc_data {
struct input_dev *input_dev;
struct resource *res;
struct tsc_regs __iomem *regs;
struct timer_list timer;
spinlock_t lock;
struct clk *clk;
struct device *dev;
int sample_count;
struct sample samples[TSC_SAMPLES];
int tsc_irq;
};
static int tsc_read_sample(struct tsc_data *ts, struct sample* sample)
{
int x, y, z1, z2, t, p = 0;
u32 val;
val = tsc_read(ts, chval[0]);
if (val & DATA_VALID)
x = val & 0xffff;
else
return -EINVAL;
y = tsc_read(ts, chval[1]) & 0xffff;
z1 = tsc_read(ts, chval[2]) & 0xffff;
z2 = tsc_read(ts, chval[3]) & 0xffff;
if (z1) {
t = ((600 * x) * (z2 - z1));
p = t / (u32) (z1 << 12);
if (p < 0)
p = 0;
}
sample->x = x;
sample->y = y;
sample->p = p;
return 0;
}
static void tsc_poll(unsigned long data)
{
struct tsc_data *ts = (struct tsc_data *)data;
unsigned long flags;
int i, val, x, y, p;
spin_lock_irqsave(&ts->lock, flags);
if (ts->sample_count >= TSC_SKIP) {
input_report_abs(ts->input_dev, ABS_PRESSURE, 0);
input_report_key(ts->input_dev, BTN_TOUCH, 0);
input_sync(ts->input_dev);
} else if (ts->sample_count > 0) {
/*
* A touch event lasted less than our skip count. Salvage and
* report anyway.
*/
for (i = 0, val = 0; i < ts->sample_count; i++)
val += ts->samples[i].x;
x = val / ts->sample_count;
for (i = 0, val = 0; i < ts->sample_count; i++)
val += ts->samples[i].y;
y = val / ts->sample_count;
for (i = 0, val = 0; i < ts->sample_count; i++)
val += ts->samples[i].p;
p = val / ts->sample_count;
input_report_abs(ts->input_dev, ABS_X, x);
input_report_abs(ts->input_dev, ABS_Y, y);
input_report_abs(ts->input_dev, ABS_PRESSURE, p);
input_report_key(ts->input_dev, BTN_TOUCH, 1);
input_sync(ts->input_dev);
}
ts->sample_count = 0;
spin_unlock_irqrestore(&ts->lock, flags);
}
static irqreturn_t tsc_irq(int irq, void *dev_id)
{
struct tsc_data *ts = (struct tsc_data *)dev_id;
struct sample *sample;
int index;
spin_lock(&ts->lock);
index = ts->sample_count % TSC_SAMPLES;
sample = &ts->samples[index];
if (tsc_read_sample(ts, sample) < 0)
goto out;
if (++ts->sample_count >= TSC_SKIP) {
index = (ts->sample_count - TSC_TAIL_SKIP - 1) % TSC_SAMPLES;
sample = &ts->samples[index];
input_report_abs(ts->input_dev, ABS_X, sample->x);
input_report_abs(ts->input_dev, ABS_Y, sample->y);
input_report_abs(ts->input_dev, ABS_PRESSURE, sample->p);
if (ts->sample_count == TSC_SKIP)
input_report_key(ts->input_dev, BTN_TOUCH, 1);
input_sync(ts->input_dev);
}
mod_timer(&ts->timer, jiffies + TSC_PENUP_POLL);
out:
spin_unlock(&ts->lock);
return IRQ_HANDLED;
}
static int tsc_start(struct input_dev *dev)
{
struct tsc_data *ts = input_get_drvdata(dev);
unsigned long timeout = jiffies + msecs_to_jiffies(IDLE_TIMEOUT);
u32 val;
clk_enable(ts->clk);
/* Go to idle mode, before any initialization */
while (time_after(timeout, jiffies)) {
if (tsc_read(ts, tscm) & IDLE)
break;
}
if (time_before(timeout, jiffies)) {
dev_warn(ts->dev, "timeout waiting for idle\n");
clk_disable(ts->clk);
return -EIO;
}
/* Configure TSC Control register*/
val = (PONBG | PON | PVSTC(4) | ONE_SHOT | ZMEASURE_EN);
tsc_write(ts, tscm, val);
/* Bring TSC out of reset: Clear AFE reset bit */
val &= ~(AFERST);
tsc_write(ts, tscm, val);
/* Configure all pins for hardware control*/
tsc_write(ts, bwcm, 0);
/* Finally enable the TSC */
tsc_set_bits(ts, tscm, TSC_EN);
return 0;
}
static void tsc_stop(struct input_dev *dev)
{
struct tsc_data *ts = input_get_drvdata(dev);
tsc_clr_bits(ts, tscm, TSC_EN);
synchronize_irq(ts->tsc_irq);
del_timer_sync(&ts->timer);
clk_disable(ts->clk);
}
static int tsc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct tsc_data *ts;
int error = 0;
u32 rev = 0;
ts = kzalloc(sizeof(struct tsc_data), GFP_KERNEL);
if (!ts) {
dev_err(dev, "cannot allocate device info\n");
return -ENOMEM;
}
ts->dev = dev;
spin_lock_init(&ts->lock);
setup_timer(&ts->timer, tsc_poll, (unsigned long)ts);
platform_set_drvdata(pdev, ts);
ts->tsc_irq = platform_get_irq(pdev, 0);
if (ts->tsc_irq < 0) {
dev_err(dev, "cannot determine device interrupt\n");
error = -ENODEV;
goto error_res;
}
ts->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!ts->res) {
dev_err(dev, "cannot determine register area\n");
error = -ENODEV;
goto error_res;
}
if (!request_mem_region(ts->res->start, resource_size(ts->res),
pdev->name)) {
dev_err(dev, "cannot claim register memory\n");
ts->res = NULL;
error = -EINVAL;
goto error_res;
}
ts->regs = ioremap(ts->res->start, resource_size(ts->res));
if (!ts->regs) {
dev_err(dev, "cannot map register memory\n");
error = -ENOMEM;
goto error_map;
}
ts->clk = clk_get(dev, NULL);
if (IS_ERR(ts->clk)) {
dev_err(dev, "cannot claim device clock\n");
error = PTR_ERR(ts->clk);
goto error_clk;
}
error = request_threaded_irq(ts->tsc_irq, NULL, tsc_irq, IRQF_ONESHOT,
dev_name(dev), ts);
if (error < 0) {
dev_err(ts->dev, "Could not allocate ts irq\n");
goto error_irq;
}
ts->input_dev = input_allocate_device();
if (!ts->input_dev) {
dev_err(dev, "cannot allocate input device\n");
error = -ENOMEM;
goto error_input;
}
input_set_drvdata(ts->input_dev, ts);
ts->input_dev->name = pdev->name;
ts->input_dev->id.bustype = BUS_HOST;
ts->input_dev->dev.parent = &pdev->dev;
ts->input_dev->open = tsc_start;
ts->input_dev->close = tsc_stop;
clk_enable(ts->clk);
rev = tsc_read(ts, rev);
ts->input_dev->id.product = ((rev >> 8) & 0x07);
ts->input_dev->id.version = ((rev >> 16) & 0xfff);
clk_disable(ts->clk);
__set_bit(EV_KEY, ts->input_dev->evbit);
__set_bit(EV_ABS, ts->input_dev->evbit);
__set_bit(BTN_TOUCH, ts->input_dev->keybit);
input_set_abs_params(ts->input_dev, ABS_X, 0, 0xffff, 5, 0);
input_set_abs_params(ts->input_dev, ABS_Y, 0, 0xffff, 5, 0);
input_set_abs_params(ts->input_dev, ABS_PRESSURE, 0, 4095, 128, 0);
error = input_register_device(ts->input_dev);
if (error < 0) {
dev_err(dev, "failed input device registration\n");
goto error_reg;
}
return 0;
error_reg:
input_free_device(ts->input_dev);
error_input:
free_irq(ts->tsc_irq, ts);
error_irq:
clk_put(ts->clk);
error_clk:
iounmap(ts->regs);
error_map:
release_mem_region(ts->res->start, resource_size(ts->res));
error_res:
kfree(ts);
return error;
}
static int tsc_remove(struct platform_device *pdev)
{
struct tsc_data *ts = platform_get_drvdata(pdev);
input_unregister_device(ts->input_dev);
free_irq(ts->tsc_irq, ts);
clk_put(ts->clk);
iounmap(ts->regs);
release_mem_region(ts->res->start, resource_size(ts->res));
kfree(ts);
return 0;
}
static struct platform_driver tsc_driver = {
.probe = tsc_probe,
.remove = tsc_remove,
.driver.name = "tnetv107x-ts",
.driver.owner = THIS_MODULE,
};
module_platform_driver(tsc_driver);
MODULE_AUTHOR("Cyril Chemparathy");
MODULE_DESCRIPTION("TNETV107X Touchscreen Driver");
MODULE_ALIAS("platform:tnetv107x-ts");
MODULE_LICENSE("GPL");