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android_kernel_motorola_sm6225/drivers/input/touchscreen/atmel_tsadcc.c
Dan Liang d8c1f317d1 Input: atmel_tsadcc - improve accuracy 
Discard the last sample just before pen is up because it is quite often
errorneous.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Dan Liang <dan.liang@atmel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-09-10 12:12:24 -04:00

343 lines
11 KiB
C
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/*
* Atmel Touch Screen Driver
*
* Copyright (c) 2008 ATMEL
* Copyright (c) 2008 Dan Liang
* Copyright (c) 2008 TimeSys Corporation
* Copyright (c) 2008 Justin Waters
*
* Based on touchscreen code from Atmel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/err.h>
#include <linux/kernel.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>
/* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
#define ATMEL_TSADCC_CR 0x00 /* Control register */
#define ATMEL_TSADCC_SWRST (1 << 0) /* Software Reset*/
#define ATMEL_TSADCC_START (1 << 1) /* Start conversion */
#define ATMEL_TSADCC_MR 0x04 /* Mode register */
#define ATMEL_TSADCC_TSAMOD (3 << 0) /* ADC mode */
#define ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE (0x0) /* ADC Mode */
#define ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE (0x1) /* Touch Screen Only Mode */
#define ATMEL_TSADCC_LOWRES (1 << 4) /* Resolution selection */
#define ATMEL_TSADCC_SLEEP (1 << 5) /* Sleep mode */
#define ATMEL_TSADCC_PENDET (1 << 6) /* Pen Detect selection */
#define ATMEL_TSADCC_PRESCAL (0x3f << 8) /* Prescalar Rate Selection */
#define ATMEL_TSADCC_STARTUP (0x7f << 16) /* Start Up time */
#define ATMEL_TSADCC_SHTIM (0xf << 24) /* Sample & Hold time */
#define ATMEL_TSADCC_PENDBC (0xf << 28) /* Pen Detect debouncing time */
#define ATMEL_TSADCC_TRGR 0x08 /* Trigger register */
#define ATMEL_TSADCC_TRGMOD (7 << 0) /* Trigger mode */
#define ATMEL_TSADCC_TRGMOD_NONE (0 << 0)
#define ATMEL_TSADCC_TRGMOD_EXT_RISING (1 << 0)
#define ATMEL_TSADCC_TRGMOD_EXT_FALLING (2 << 0)
#define ATMEL_TSADCC_TRGMOD_EXT_ANY (3 << 0)
#define ATMEL_TSADCC_TRGMOD_PENDET (4 << 0)
#define ATMEL_TSADCC_TRGMOD_PERIOD (5 << 0)
#define ATMEL_TSADCC_TRGMOD_CONTINUOUS (6 << 0)
#define ATMEL_TSADCC_TRGPER (0xffff << 16) /* Trigger period */
#define ATMEL_TSADCC_TSR 0x0C /* Touch Screen register */
#define ATMEL_TSADCC_TSFREQ (0xf << 0) /* TS Frequency in Interleaved mode */
#define ATMEL_TSADCC_TSSHTIM (0xf << 24) /* Sample & Hold time */
#define ATMEL_TSADCC_CHER 0x10 /* Channel Enable register */
#define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable register */
#define ATMEL_TSADCC_CHSR 0x18 /* Channel Status register */
#define ATMEL_TSADCC_CH(n) (1 << (n)) /* Channel number */
#define ATMEL_TSADCC_SR 0x1C /* Status register */
#define ATMEL_TSADCC_EOC(n) (1 << ((n)+0)) /* End of conversion for channel N */
#define ATMEL_TSADCC_OVRE(n) (1 << ((n)+8)) /* Overrun error for channel N */
#define ATMEL_TSADCC_DRDY (1 << 16) /* Data Ready */
#define ATMEL_TSADCC_GOVRE (1 << 17) /* General Overrun Error */
#define ATMEL_TSADCC_ENDRX (1 << 18) /* End of RX Buffer */
#define ATMEL_TSADCC_RXBUFF (1 << 19) /* TX Buffer full */
#define ATMEL_TSADCC_PENCNT (1 << 20) /* Pen contact */
#define ATMEL_TSADCC_NOCNT (1 << 21) /* No contact */
#define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */
#define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */
#define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable register */
#define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable register */
#define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask register */
#define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 */
#define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 */
#define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 */
#define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 */
#define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 */
#define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 */
#define ADC_CLOCK 1000000
struct atmel_tsadcc {
struct input_dev *input;
char phys[32];
struct clk *clk;
int irq;
unsigned int prev_absx;
unsigned int prev_absy;
unsigned char bufferedmeasure;
};
static void __iomem *tsc_base;
#define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg))
#define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg))
static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
{
struct atmel_tsadcc *ts_dev = (struct atmel_tsadcc *)dev;
struct input_dev *input_dev = ts_dev->input;
unsigned int status;
unsigned int reg;
status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);
if (status & ATMEL_TSADCC_NOCNT) {
/* Contact lost */
reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;
atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
atmel_tsadcc_write(ATMEL_TSADCC_IDR,
ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
input_report_key(input_dev, BTN_TOUCH, 0);
ts_dev->bufferedmeasure = 0;
input_sync(input_dev);
} else if (status & ATMEL_TSADCC_PENCNT) {
/* Pen detected */
reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
reg &= ~ATMEL_TSADCC_PENDBC;
atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
atmel_tsadcc_write(ATMEL_TSADCC_IER,
ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));
} else if (status & ATMEL_TSADCC_EOC(3)) {
/* Conversion finished */
if (ts_dev->bufferedmeasure) {
/* Last measurement is always discarded, since it can
* be erroneous.
* Always report previous measurement */
input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);
input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);
input_report_key(input_dev, BTN_TOUCH, 1);
input_sync(input_dev);
} else
ts_dev->bufferedmeasure = 1;
/* Now make new measurement */
ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);
ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
}
return IRQ_HANDLED;
}
/*
* The functions for inserting/removing us as a module.
*/
static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
{
struct atmel_tsadcc *ts_dev;
struct input_dev *input_dev;
struct resource *res;
int err = 0;
unsigned int prsc;
unsigned int reg;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "no mmio resource defined.\n");
return -ENXIO;
}
/* Allocate memory for device */
ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
if (!ts_dev) {
dev_err(&pdev->dev, "failed to allocate memory.\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, ts_dev);
input_dev = input_allocate_device();
if (!input_dev) {
dev_err(&pdev->dev, "failed to allocate input device.\n");
err = -EBUSY;
goto err_free_mem;
}
ts_dev->irq = platform_get_irq(pdev, 0);
if (ts_dev->irq < 0) {
dev_err(&pdev->dev, "no irq ID is designated.\n");
err = -ENODEV;
goto err_free_dev;
}
if (!request_mem_region(res->start, res->end - res->start + 1,
"atmel tsadcc regs")) {
dev_err(&pdev->dev, "resources is unavailable.\n");
err = -EBUSY;
goto err_free_dev;
}
tsc_base = ioremap(res->start, res->end - res->start + 1);
if (!tsc_base) {
dev_err(&pdev->dev, "failed to map registers.\n");
err = -ENOMEM;
goto err_release_mem;
}
err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED,
pdev->dev.driver->name, ts_dev);
if (err) {
dev_err(&pdev->dev, "failed to allocate irq.\n");
goto err_unmap_regs;
}
ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
if (IS_ERR(ts_dev->clk)) {
dev_err(&pdev->dev, "failed to get ts_clk\n");
err = PTR_ERR(ts_dev->clk);
goto err_free_irq;
}
ts_dev->input = input_dev;
ts_dev->bufferedmeasure = 0;
snprintf(ts_dev->phys, sizeof(ts_dev->phys),
"%s/input0", pdev->dev.bus_id);
input_dev->name = "atmel touch screen controller";
input_dev->phys = ts_dev->phys;
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, 0x3FF, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
/* clk_enable() always returns 0, no need to check it */
clk_enable(ts_dev->clk);
prsc = clk_get_rate(ts_dev->clk);
dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);
prsc = prsc / ADC_CLOCK / 2 - 1;
reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE |
((0x00 << 5) & ATMEL_TSADCC_SLEEP) | /* Normal Mode */
((0x01 << 6) & ATMEL_TSADCC_PENDET) | /* Enable Pen Detect */
((prsc << 8) & ATMEL_TSADCC_PRESCAL) | /* PRESCAL */
((0x13 << 16) & ATMEL_TSADCC_STARTUP) | /* STARTUP */
((0x0F << 28) & ATMEL_TSADCC_PENDBC); /* PENDBC */
atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM);
atmel_tsadcc_read(ATMEL_TSADCC_SR);
atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
/* All went ok, so register to the input system */
err = input_register_device(input_dev);
if (err)
goto err_fail;
return 0;
err_fail:
clk_disable(ts_dev->clk);
clk_put(ts_dev->clk);
err_free_irq:
free_irq(ts_dev->irq, ts_dev);
err_unmap_regs:
iounmap(tsc_base);
err_release_mem:
release_mem_region(res->start, res->end - res->start + 1);
err_free_dev:
input_free_device(ts_dev->input);
err_free_mem:
kfree(ts_dev);
return err;
}
static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
{
struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev);
struct resource *res;
free_irq(ts_dev->irq, ts_dev);
input_unregister_device(ts_dev->input);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
iounmap(tsc_base);
release_mem_region(res->start, res->end - res->start + 1);
clk_disable(ts_dev->clk);
clk_put(ts_dev->clk);
kfree(ts_dev);
return 0;
}
static struct platform_driver atmel_tsadcc_driver = {
.probe = atmel_tsadcc_probe,
.remove = __devexit_p(atmel_tsadcc_remove),
.driver = {
.name = "atmel_tsadcc",
},
};
static int __init atmel_tsadcc_init(void)
{
return platform_driver_register(&atmel_tsadcc_driver);
}
static void __exit atmel_tsadcc_exit(void)
{
platform_driver_unregister(&atmel_tsadcc_driver);
}
module_init(atmel_tsadcc_init);
module_exit(atmel_tsadcc_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Atmel TouchScreen Driver");
MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");
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