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/*
* TSC2005 touchscreen driver
*
* Copyright (C) 2006-2010 Nokia Corporation
*
* Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
* based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.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; 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/spi/spi.h>
#include <linux/spi/tsc2005.h>
/*
* The touchscreen interface operates as follows:
*
* 1) Pen is pressed against the touchscreen.
* 2) TSC2005 performs AD conversion.
* 3) After the conversion is done TSC2005 drives DAV line down.
* 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
* 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
* values.
* 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
* tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
* 7) When the penup timer expires, there have not been touch or DAV interrupts
* during the last 40ms which means the pen has been lifted.
*
* ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
* after a configurable period (in ms) of activity. If esd_timeout is 0, the
* watchdog is disabled.
*/
/* control byte 1 */
#define TSC2005_CMD 0x80
#define TSC2005_CMD_NORMAL 0x00
#define TSC2005_CMD_STOP 0x01
#define TSC2005_CMD_12BIT 0x04
/* control byte 0 */
#define TSC2005_REG_READ 0x0001
#define TSC2005_REG_PND0 0x0002
#define TSC2005_REG_X 0x0000
#define TSC2005_REG_Y 0x0008
#define TSC2005_REG_Z1 0x0010
#define TSC2005_REG_Z2 0x0018
#define TSC2005_REG_TEMP_HIGH 0x0050
#define TSC2005_REG_CFR0 0x0060
#define TSC2005_REG_CFR1 0x0068
#define TSC2005_REG_CFR2 0x0070
/* configuration register 0 */
#define TSC2005_CFR0_PRECHARGE_276US 0x0040
#define TSC2005_CFR0_STABTIME_1MS 0x0300
#define TSC2005_CFR0_CLOCK_1MHZ 0x1000
#define TSC2005_CFR0_RESOLUTION12 0x2000
#define TSC2005_CFR0_PENMODE 0x8000
#define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
TSC2005_CFR0_CLOCK_1MHZ | \
TSC2005_CFR0_RESOLUTION12 | \
TSC2005_CFR0_PRECHARGE_276US | \
TSC2005_CFR0_PENMODE)
/* bits common to both read and write of configuration register 0 */
#define TSC2005_CFR0_RW_MASK 0x3fff
/* configuration register 1 */
#define TSC2005_CFR1_BATCHDELAY_4MS 0x0003
#define TSC2005_CFR1_INITVALUE TSC2005_CFR1_BATCHDELAY_4MS
/* configuration register 2 */
#define TSC2005_CFR2_MAVE_Z 0x0004
#define TSC2005_CFR2_MAVE_Y 0x0008
#define TSC2005_CFR2_MAVE_X 0x0010
#define TSC2005_CFR2_AVG_7 0x0800
#define TSC2005_CFR2_MEDIUM_15 0x3000
#define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_MAVE_X | \
TSC2005_CFR2_MAVE_Y | \
TSC2005_CFR2_MAVE_Z | \
TSC2005_CFR2_MEDIUM_15 | \
TSC2005_CFR2_AVG_7)
#define MAX_12BIT 0xfff
#define TSC2005_SPI_MAX_SPEED_HZ 10000000
#define TSC2005_PENUP_TIME_MS 40
struct tsc2005_spi_rd {
struct spi_transfer spi_xfer;
u32 spi_tx;
u32 spi_rx;
};
struct tsc2005 {
struct spi_device *spi;
struct spi_message spi_read_msg;
struct tsc2005_spi_rd spi_x;
struct tsc2005_spi_rd spi_y;
struct tsc2005_spi_rd spi_z1;
struct tsc2005_spi_rd spi_z2;
struct input_dev *idev;
char phys[32];
struct mutex mutex;
/* raw copy of previous x,y,z */
int in_x;
int in_y;
int in_z1;
int in_z2;
spinlock_t lock;
struct timer_list penup_timer;
unsigned int esd_timeout;
struct delayed_work esd_work;
unsigned long last_valid_interrupt;
unsigned int x_plate_ohm;
bool opened;
bool suspended;
bool pen_down;
void (*set_reset)(bool enable);
};
static int tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
{
u8 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
struct spi_transfer xfer = {
.tx_buf = &tx,
.len = 1,
.bits_per_word = 8,
};
struct spi_message msg;
int error;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error) {
dev_err(&ts->spi->dev, "%s: failed, command: %x, error: %d\n",
__func__, cmd, error);
return error;
}
return 0;
}
static int tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
{
u32 tx = ((reg | TSC2005_REG_PND0) << 16) | value;
struct spi_transfer xfer = {
.tx_buf = &tx,
.len = 4,
.bits_per_word = 24,
};
struct spi_message msg;
int error;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error) {
dev_err(&ts->spi->dev,
"%s: failed, register: %x, value: %x, error: %d\n",
__func__, reg, value, error);
return error;
}
return 0;
}
static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last)
{
memset(rd, 0, sizeof(*rd));
rd->spi_tx = (reg | TSC2005_REG_READ) << 16;
rd->spi_xfer.tx_buf = &rd->spi_tx;
rd->spi_xfer.rx_buf = &rd->spi_rx;
rd->spi_xfer.len = 4;
rd->spi_xfer.bits_per_word = 24;
rd->spi_xfer.cs_change = !last;
}
static int tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value)
{
struct tsc2005_spi_rd spi_rd;
struct spi_message msg;
int error;
tsc2005_setup_read(&spi_rd, reg, true);
spi_message_init(&msg);
spi_message_add_tail(&spi_rd.spi_xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error)
return error;
*value = spi_rd.spi_rx;
return 0;
}
static void tsc2005_update_pen_state(struct tsc2005 *ts,
int x, int y, int pressure)
{
if (pressure) {
input_report_abs(ts->idev, ABS_X, x);
input_report_abs(ts->idev, ABS_Y, y);
input_report_abs(ts->idev, ABS_PRESSURE, pressure);
if (!ts->pen_down) {
input_report_key(ts->idev, BTN_TOUCH, !!pressure);
ts->pen_down = true;
}
} else {
input_report_abs(ts->idev, ABS_PRESSURE, 0);
if (ts->pen_down) {
input_report_key(ts->idev, BTN_TOUCH, 0);
ts->pen_down = false;
}
}
input_sync(ts->idev);
dev_dbg(&ts->spi-><
|