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linux/drivers/input/touchscreen/lpc32xx_ts.c

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/*
* LPC32xx built-in touchscreen driver
*
* Copyright (C) 2010 NXP Semiconductors
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>
/*
* Touchscreen controller register offsets
*/
#define LPC32XX_TSC_STAT 0x00
#define LPC32XX_TSC_SEL 0x04
#define LPC32XX_TSC_CON 0x08
#define LPC32XX_TSC_FIFO 0x0C
#define LPC32XX_TSC_DTR 0x10
#define LPC32XX_TSC_RTR 0x14
#define LPC32XX_TSC_UTR 0x18
#define LPC32XX_TSC_TTR 0x1C
#define LPC32XX_TSC_DXP 0x20
#define LPC32XX_TSC_MIN_X 0x24
#define LPC32XX_TSC_MAX_X 0x28
#define LPC32XX_TSC_MIN_Y 0x2C
#define LPC32XX_TSC_MAX_Y 0x30
#define LPC32XX_TSC_AUX_UTR 0x34
#define LPC32XX_TSC_AUX_MIN 0x38
#define LPC32XX_TSC_AUX_MAX 0x3C
#define LPC32XX_TSC_STAT_FIFO_OVRRN (1 << 8)
#define LPC32XX_TSC_STAT_FIFO_EMPTY (1 << 7)
#define LPC32XX_TSC_SEL_DEFVAL 0x0284
#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 (0x1 << 11)
#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s) ((10 - (s)) << 7)
#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s) ((10 - (s)) << 4)
#define LPC32XX_TSC_ADCCON_POWER_UP (1 << 2)
#define LPC32XX_TSC_ADCCON_AUTO_EN (1 << 0)
#define LPC32XX_TSC_FIFO_TS_P_LEVEL (1 << 31)
#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x) (((x) & 0x03FF0000) >> 16)
#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y) ((y) & 0x000003FF)
#define LPC32XX_TSC_ADCDAT_VALUE_MASK 0x000003FF
#define LPC32XX_TSC_MIN_XY_VAL 0x0
#define LPC32XX_TSC_MAX_XY_VAL 0x3FF
#define MOD_NAME "ts-lpc32xx"
#define tsc_readl(dev, reg) \
__raw_readl((dev)->tsc_base + (reg))
#define tsc_writel(dev, reg, val) \
__raw_writel((val), (dev)->tsc_base + (reg))
struct lpc32xx_tsc {
struct input_dev *dev;
void __iomem *tsc_base;
int irq;
struct clk *clk;
};
static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
{
while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
LPC32XX_TSC_STAT_FIFO_EMPTY))
tsc_readl(tsc, LPC32XX_TSC_FIFO);
}
static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
{
u32 tmp, rv[4], xs[4], ys[4];
int idx;
struct lpc32xx_tsc *tsc = dev_id;
struct input_dev *input = tsc->dev;
tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);
if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
/* FIFO overflow - throw away samples */
lpc32xx_fifo_clear(tsc);
return IRQ_HANDLED;
}
/*
* Gather and normalize 4 samples. Pen-up events may have less
* than 4 samples, but its ok to pop 4 and let the last sample
* pen status check drop the samples.
*/
idx = 0;
while (idx < 4 &&
!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
LPC32XX_TSC_STAT_FIFO_EMPTY)) {
tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
rv[idx] = tmp;
idx++;
}
/* Data is only valid if pen is still down in last sample */
if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
/* Use average of 2nd and 3rd sample for position */
input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
input_report_key(input, BTN_TOUCH, 1);
} else {
input_report_key(input, BTN_TOUCH, 0);
}
input_sync(input);
return IRQ_HANDLED;
}
static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
{
/* Disable auto mode */
tsc_writel(tsc, LPC32XX_TSC_CON,
tsc_readl(tsc, LPC32XX_TSC_CON) &
~LPC32XX_TSC_ADCCON_AUTO_EN);
clk_disable_unprepare(tsc->clk);
}
static int lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
{
u32 tmp;
int err;
err = clk_prepare_enable(tsc->clk);
if (err)
return err;
tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;
/* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
tsc_writel(tsc, LPC32XX_TSC_CON, tmp);
/* These values are all preset */
tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);
/* Aux support is not used */
tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);
/*
* Set sample rate to about 240Hz per X/Y pair. A single measurement
* consists of 4 pairs which gives about a 60Hz sample rate based on
* a stable 32768Hz clock source. Values are in clocks.
* Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
*/
tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
tsc_writel(tsc, LPC32XX_TSC_UTR, 88);
lpc32xx_fifo_clear(tsc);
/* Enable automatic ts event capture */
tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);
return 0;
}
static int lpc32xx_ts_open(struct input_dev *dev)
{
struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
return lpc32xx_setup_tsc(tsc);
}
static void lpc32xx_ts_close(struct input_dev *dev)
{
struct lpc32xx_tsc *tsc = input_get_drvdata(dev);
lpc32xx_stop_tsc(tsc);
}
static int lpc32xx_ts_probe(struct platform_device *pdev)
{
struct lpc32xx_tsc *tsc;
struct input_dev *input;
struct resource *res;
resource_size_t size;
int irq;
int error;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Can't get memory resource\n");
return -ENOENT;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "Can't get interrupt resource\n");
return irq;
}
tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
input = input_allocate_device();
if (!tsc || !input) {
dev_err(&pdev->dev, "failed allocating memory\n");
error = -ENOMEM;
goto err_free_mem;
}
tsc->dev = input;
tsc->irq = irq;
size = resource_size(res);
if (!request_mem_region(res->start, size, pdev->name)) {
dev_err(&pdev->dev, "TSC registers are not free\n");
error = -EBUSY;
goto err_free_mem;
}
tsc->tsc_base = ioremap(res->start, size);
if (!tsc->tsc_base) {
dev_err(&pdev->dev, "Can't map memory\n");
error = -ENOMEM;
goto err_release_mem;
}
tsc->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(tsc->clk)) {
dev_err(&pdev->dev, "failed getting clock\n");
error = PTR_ERR(tsc->clk);
goto err_unmap;
}
input->name = MOD_NAME;
input->phys = "lpc32xx/input0";
input->id.bustype = BUS_HOST;
input->id.vendor = 0x0001;
input->id.product = 0x0002;
input->id.version = 0x0100;
input->dev.parent = &pdev->dev;
input->open = lpc32xx_ts_open;
input->close = lpc32xx_ts_close;
input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
LPC32XX_TSC_MAX_XY_VAL, 0, 0);
input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
LPC32XX_TSC_MAX_XY_VAL, 0, 0);
input_set_drvdata(input, tsc);
error = request_irq(tsc->irq, lpc32xx_ts_interrupt,
0, pdev->name, tsc);
if (error) {
dev_err(&pdev->dev, "failed requesting interrupt\n");
goto err_put_clock;
}
error = input_register_device(input);
if (error) {
dev_err(&pdev->dev, "failed registering input device\n");
goto err_free_irq;
}
platform_set_drvdata(pdev, tsc);
device_init_wakeup(&pdev->dev, 1);
return 0;
err_free_irq:
free_irq(tsc->irq, tsc);
err_put_clock:
clk_put(tsc->clk);
err_unmap:
iounmap(tsc->tsc_base);
err_release_mem:
release_mem_region(res->start, size);
err_free_mem:
input_free_device(input);
kfree(tsc);
return error;
}
static int lpc32xx_ts_remove(struct platform_device *pdev)
{
struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
struct resource *res;
free_irq(tsc->irq, tsc);
input_unregister_device(tsc->dev);
clk_put(tsc->clk);
iounmap(tsc->tsc_base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, resource_size(res));
kfree(tsc);
return 0;
}
#ifdef CONFIG_PM
static int lpc32xx_ts_suspend(struct device *dev)
{
struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
struct input_dev *input = tsc->dev;
/*
* Suspend and resume can be called when the device hasn't been
* enabled. If there are no users that have the device open, then
* avoid calling the TSC stop and start functions as the TSC
* isn't yet clocked.
*/
mutex_lock(&input->mutex);
if (input->users) {
if (device_may_wakeup(dev))
enable_irq_wake(tsc->irq);
else
lpc32xx_stop_tsc(tsc);
}
mutex_unlock(&input->mutex);
return 0;
}
static int lpc32xx_ts_resume(struct device *dev)
{
struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
struct input_dev *input = tsc->dev;
mutex_lock(&input->mutex);
if (input->users) {
if (device_may_wakeup(dev))
disable_irq_wake(tsc->irq);
else
lpc32xx_setup_tsc(tsc);
}
mutex_unlock(&input->mutex);
return 0;
}
static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
.suspend = lpc32xx_ts_suspend,
.resume = lpc32xx_ts_resume,
};
#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
#else
#define LPC32XX_TS_PM_OPS NULL
#endif
#ifdef CONFIG_OF
static const struct of_device_id lpc32xx_tsc_of_match[] = {
{ .compatible = "nxp,lpc3220-tsc", },
{ },
};
MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match);
#endif
static struct platform_driver lpc32xx_ts_driver = {
.probe = lpc32xx_ts_probe,
.remove = lpc32xx_ts_remove,
.driver = {
.name = MOD_NAME,
.pm = LPC32XX_TS_PM_OPS,
.of_match_table = of_match_ptr(lpc32xx_tsc_of_match),
},
};
module_platform_driver(lpc32xx_ts_driver);
MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
MODULE_DESCRIPTION("LPC32XX TSC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lpc32xx_ts");
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