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* TSC2005 touchscreen driver
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* Copyright (C) 2006-2010 Nokia Corporation
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* Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
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* based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/tsc2005.h>
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* The touchscreen interface operates as follows:
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* 1) Pen is pressed against the touchscreen.
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* 2) TSC2005 performs AD conversion.
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* 3) After the conversion is done TSC2005 drives DAV line down.
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* 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
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* 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
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* 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
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* tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
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* 7) When the penup timer expires, there have not been touch or DAV interrupts
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* during the last 40ms which means the pen has been lifted.
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* ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
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* after a configurable period (in ms) of activity. If esd_timeout is 0, the
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* watchdog is disabled.
54
#define TSC2005_CMD 0x80
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#define TSC2005_CMD_NORMAL 0x00
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#define TSC2005_CMD_STOP 0x01
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#define TSC2005_CMD_12BIT 0x04
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#define TSC2005_REG_READ 0x0001
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#define TSC2005_REG_PND0 0x0002
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#define TSC2005_REG_X 0x0000
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#define TSC2005_REG_Y 0x0008
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#define TSC2005_REG_Z1 0x0010
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#define TSC2005_REG_Z2 0x0018
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#define TSC2005_REG_TEMP_HIGH 0x0050
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#define TSC2005_REG_CFR0 0x0060
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#define TSC2005_REG_CFR1 0x0068
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#define TSC2005_REG_CFR2 0x0070
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/* configuration register 0 */
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#define TSC2005_CFR0_PRECHARGE_276US 0x0040
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#define TSC2005_CFR0_STABTIME_1MS 0x0300
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#define TSC2005_CFR0_CLOCK_1MHZ 0x1000
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#define TSC2005_CFR0_RESOLUTION12 0x2000
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#define TSC2005_CFR0_PENMODE 0x8000
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#define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
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TSC2005_CFR0_CLOCK_1MHZ | \
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TSC2005_CFR0_RESOLUTION12 | \
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TSC2005_CFR0_PRECHARGE_276US | \
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/* bits common to both read and write of configuration register 0 */
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#define TSC2005_CFR0_RW_MASK 0x3fff
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/* configuration register 1 */
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#define TSC2005_CFR1_BATCHDELAY_4MS 0x0003
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#define TSC2005_CFR1_INITVALUE TSC2005_CFR1_BATCHDELAY_4MS
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/* configuration register 2 */
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#define TSC2005_CFR2_MAVE_Z 0x0004
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#define TSC2005_CFR2_MAVE_Y 0x0008
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#define TSC2005_CFR2_MAVE_X 0x0010
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#define TSC2005_CFR2_AVG_7 0x0800
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#define TSC2005_CFR2_MEDIUM_15 0x3000
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#define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_MAVE_X | \
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TSC2005_CFR2_MAVE_Y | \
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TSC2005_CFR2_MAVE_Z | \
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TSC2005_CFR2_MEDIUM_15 | \
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#define MAX_12BIT 0xfff
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#define TSC2005_SPI_MAX_SPEED_HZ 10000000
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#define TSC2005_PENUP_TIME_MS 40
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struct tsc2005_spi_rd {
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struct spi_transfer spi_xfer;
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struct spi_device *spi;
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struct spi_message spi_read_msg;
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struct tsc2005_spi_rd spi_x;
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struct tsc2005_spi_rd spi_y;
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struct tsc2005_spi_rd spi_z1;
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struct tsc2005_spi_rd spi_z2;
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struct input_dev *idev;
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/* raw copy of previous x,y,z */
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struct timer_list penup_timer;
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unsigned int esd_timeout;
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struct delayed_work esd_work;
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unsigned long last_valid_interrupt;
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unsigned int x_plate_ohm;
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void (*set_reset)(bool enable);
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static int tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
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u8 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
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struct spi_transfer xfer = {
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struct spi_message msg;
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spi_message_init(&msg);
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spi_message_add_tail(&xfer, &msg);
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error = spi_sync(ts->spi, &msg);
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dev_err(&ts->spi->dev, "%s: failed, command: %x, error: %d\n",
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__func__, cmd, error);
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static int tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
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u32 tx = ((reg | TSC2005_REG_PND0) << 16) | value;
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struct spi_transfer xfer = {
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struct spi_message msg;
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spi_message_init(&msg);
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spi_message_add_tail(&xfer, &msg);
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error = spi_sync(ts->spi, &msg);
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dev_err(&ts->spi->dev,
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"%s: failed, register: %x, value: %x, error: %d\n",
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__func__, reg, value, error);
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static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last)
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memset(rd, 0, sizeof(*rd));
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rd->spi_tx = (reg | TSC2005_REG_READ) << 16;
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rd->spi_xfer.tx_buf = &rd->spi_tx;
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rd->spi_xfer.rx_buf = &rd->spi_rx;
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rd->spi_xfer.len = 4;
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rd->spi_xfer.bits_per_word = 24;
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rd->spi_xfer.cs_change = !last;
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static int tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value)
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struct tsc2005_spi_rd spi_rd;
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struct spi_message msg;
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tsc2005_setup_read(&spi_rd, reg, true);
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spi_message_init(&msg);
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spi_message_add_tail(&spi_rd.spi_xfer, &msg);
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error = spi_sync(ts->spi, &msg);
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*value = spi_rd.spi_rx;
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static void tsc2005_update_pen_state(struct tsc2005 *ts,
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int x, int y, int pressure)
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input_report_abs(ts->idev, ABS_X, x);
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input_report_abs(ts->idev, ABS_Y, y);
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input_report_abs(ts->idev, ABS_PRESSURE, pressure);
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input_report_key(ts->idev, BTN_TOUCH, !!pressure);
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input_report_abs(ts->idev, ABS_PRESSURE, 0);
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input_report_key(ts->idev, BTN_TOUCH, 0);
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ts->pen_down = false;
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input_sync(ts->idev);
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dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
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static irqreturn_t tsc2005_irq_thread(int irq, void *_ts)
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struct tsc2005 *ts = _ts;
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unsigned int pressure;
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/* read the coordinates */
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error = spi_sync(ts->spi, &ts->spi_read_msg);
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x = ts->spi_x.spi_rx;
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y = ts->spi_y.spi_rx;
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z1 = ts->spi_z1.spi_rx;
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z2 = ts->spi_z2.spi_rx;
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/* validate position */
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if (unlikely(x > MAX_12BIT || y > MAX_12BIT))
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/* Skip reading if the pressure components are out of range */
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if (unlikely(z1 == 0 || z2 > MAX_12BIT || z1 >= z2))
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* Skip point if this is a pen down with the exact same values as
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* the value before pen-up - that implies SPI fed us stale data
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ts->in_x == x && ts->in_y == y &&
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ts->in_z1 == z1 && ts->in_z2 == z2) {
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* At this point we are happy we have a valid and useful reading.
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* Remember it for later comparisons. We may now begin downsampling.
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/* Compute touch pressure resistance using equation #1 */
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pressure = x * (z2 - z1) / z1;
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pressure = pressure * ts->x_plate_ohm / 4096;
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if (unlikely(pressure > MAX_12BIT))
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spin_lock_irqsave(&ts->lock, flags);
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tsc2005_update_pen_state(ts, x, y, pressure);
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mod_timer(&ts->penup_timer,
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jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));
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spin_unlock_irqrestore(&ts->lock, flags);
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ts->last_valid_interrupt = jiffies;
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static void tsc2005_penup_timer(unsigned long data)
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struct tsc2005 *ts = (struct tsc2005 *)data;
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spin_lock_irqsave(&ts->lock, flags);
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tsc2005_update_pen_state(ts, 0, 0, 0);
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spin_unlock_irqrestore(&ts->lock, flags);
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static void tsc2005_start_scan(struct tsc2005 *ts)
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tsc2005_write(ts, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
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tsc2005_write(ts, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
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tsc2005_write(ts, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
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tsc2005_cmd(ts, TSC2005_CMD_NORMAL);
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static void tsc2005_stop_scan(struct tsc2005 *ts)
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tsc2005_cmd(ts, TSC2005_CMD_STOP);
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/* must be called with ts->mutex held */
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static void __tsc2005_disable(struct tsc2005 *ts)
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tsc2005_stop_scan(ts);
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disable_irq(ts->spi->irq);
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del_timer_sync(&ts->penup_timer);
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cancel_delayed_work_sync(&ts->esd_work);
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enable_irq(ts->spi->irq);
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/* must be called with ts->mutex held */
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static void __tsc2005_enable(struct tsc2005 *ts)
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tsc2005_start_scan(ts);
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if (ts->esd_timeout && ts->set_reset) {
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ts->last_valid_interrupt = jiffies;
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schedule_delayed_work(&ts->esd_work,
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round_jiffies_relative(
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msecs_to_jiffies(ts->esd_timeout)));
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static ssize_t tsc2005_selftest_show(struct device *dev,
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struct device_attribute *attr,
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struct spi_device *spi = to_spi_device(dev);
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struct tsc2005 *ts = spi_get_drvdata(spi);
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mutex_lock(&ts->mutex);
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* Test TSC2005 communications via temp high register.
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__tsc2005_disable(ts);
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error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig);
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dev_warn(dev, "selftest failed: read error %d\n", error);
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temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
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error = tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test);
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dev_warn(dev, "selftest failed: write error %d\n", error);
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error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
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dev_warn(dev, "selftest failed: read error %d after write\n",
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if (temp_high != temp_high_test) {
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dev_warn(dev, "selftest failed: %d != %d\n",
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temp_high, temp_high_test);
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ts->set_reset(false);
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usleep_range(100, 500); /* only 10us required */
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/* test that the reset really happened */
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error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
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dev_warn(dev, "selftest failed: read error %d after reset\n",
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if (temp_high != temp_high_orig) {
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dev_warn(dev, "selftest failed after reset: %d != %d\n",
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temp_high, temp_high_orig);
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__tsc2005_enable(ts);
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mutex_unlock(&ts->mutex);
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return sprintf(buf, "%d\n", success);
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static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL);
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static struct attribute *tsc2005_attrs[] = {
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&dev_attr_selftest.attr,
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static mode_t tsc2005_attr_is_visible(struct kobject *kobj,
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struct attribute *attr, int n)
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struct device *dev = container_of(kobj, struct device, kobj);
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struct spi_device *spi = to_spi_device(dev);
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struct tsc2005 *ts = spi_get_drvdata(spi);
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mode_t mode = attr->mode;
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if (attr == &dev_attr_selftest.attr) {
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static const struct attribute_group tsc2005_attr_group = {
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.is_visible = tsc2005_attr_is_visible,
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.attrs = tsc2005_attrs,
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static void tsc2005_esd_work(struct work_struct *work)
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struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work.work);
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if (!mutex_trylock(&ts->mutex)) {
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* If the mutex is taken, it means that disable or enable is in
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* progress. In that case just reschedule the work. If the work
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* is not needed, it will be canceled by disable.
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if (time_is_after_jiffies(ts->last_valid_interrupt +
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msecs_to_jiffies(ts->esd_timeout)))
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/* We should be able to read register without disabling interrupts. */
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error = tsc2005_read(ts, TSC2005_REG_CFR0, &r);
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!((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK)) {
501
* If we could not read our known value from configuration register 0
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* then we should reset the controller as if from power-up and start
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dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n");
507
disable_irq(ts->spi->irq);
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del_timer_sync(&ts->penup_timer);
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tsc2005_update_pen_state(ts, 0, 0, 0);
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ts->set_reset(false);
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usleep_range(100, 500); /* only 10us required */
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enable_irq(ts->spi->irq);
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tsc2005_start_scan(ts);
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mutex_unlock(&ts->mutex);
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/* re-arm the watchdog */
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schedule_delayed_work(&ts->esd_work,
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round_jiffies_relative(
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msecs_to_jiffies(ts->esd_timeout)));
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static int tsc2005_open(struct input_dev *input)
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struct tsc2005 *ts = input_get_drvdata(input);
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mutex_lock(&ts->mutex);
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__tsc2005_enable(ts);
539
mutex_unlock(&ts->mutex);
544
static void tsc2005_close(struct input_dev *input)
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struct tsc2005 *ts = input_get_drvdata(input);
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mutex_lock(&ts->mutex);
551
__tsc2005_disable(ts);
555
mutex_unlock(&ts->mutex);
558
static void __devinit tsc2005_setup_spi_xfer(struct tsc2005 *ts)
560
tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, false);
561
tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, false);
562
tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, false);
563
tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, true);
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spi_message_init(&ts->spi_read_msg);
566
spi_message_add_tail(&ts->spi_x.spi_xfer, &ts->spi_read_msg);
567
spi_message_add_tail(&ts->spi_y.spi_xfer, &ts->spi_read_msg);
568
spi_message_add_tail(&ts->spi_z1.spi_xfer, &ts->spi_read_msg);
569
spi_message_add_tail(&ts->spi_z2.spi_xfer, &ts->spi_read_msg);
572
static int __devinit tsc2005_probe(struct spi_device *spi)
574
const struct tsc2005_platform_data *pdata = spi->dev.platform_data;
576
struct input_dev *input_dev;
577
unsigned int max_x, max_y, max_p;
578
unsigned int fudge_x, fudge_y, fudge_p;
582
dev_dbg(&spi->dev, "no platform data\n");
586
fudge_x = pdata->ts_x_fudge ? : 4;
587
fudge_y = pdata->ts_y_fudge ? : 8;
588
fudge_p = pdata->ts_pressure_fudge ? : 2;
589
max_x = pdata->ts_x_max ? : MAX_12BIT;
590
max_y = pdata->ts_y_max ? : MAX_12BIT;
591
max_p = pdata->ts_pressure_max ? : MAX_12BIT;
594
dev_dbg(&spi->dev, "no irq\n");
598
spi->mode = SPI_MODE_0;
599
spi->bits_per_word = 8;
600
if (!spi->max_speed_hz)
601
spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;
603
error = spi_setup(spi);
607
ts = kzalloc(sizeof(*ts), GFP_KERNEL);
608
input_dev = input_allocate_device();
609
if (!ts || !input_dev) {
615
ts->idev = input_dev;
617
ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
618
ts->esd_timeout = pdata->esd_timeout_ms;
619
ts->set_reset = pdata->set_reset;
621
mutex_init(&ts->mutex);
623
spin_lock_init(&ts->lock);
624
setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts);
626
INIT_DELAYED_WORK(&ts->esd_work, tsc2005_esd_work);
628
tsc2005_setup_spi_xfer(ts);
630
snprintf(ts->phys, sizeof(ts->phys),
631
"%s/input-ts", dev_name(&spi->dev));
633
input_dev->name = "TSC2005 touchscreen";
634
input_dev->phys = ts->phys;
635
input_dev->id.bustype = BUS_SPI;
636
input_dev->dev.parent = &spi->dev;
637
input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
638
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
640
input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
641
input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
642
input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
644
input_dev->open = tsc2005_open;
645
input_dev->close = tsc2005_close;
647
input_set_drvdata(input_dev, ts);
649
/* Ensure the touchscreen is off */
650
tsc2005_stop_scan(ts);
652
error = request_threaded_irq(spi->irq, NULL, tsc2005_irq_thread,
653
IRQF_TRIGGER_RISING, "tsc2005", ts);
655
dev_err(&spi->dev, "Failed to request irq, err: %d\n", error);
659
spi_set_drvdata(spi, ts);
660
error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
663
"Failed to create sysfs attributes, err: %d\n", error);
664
goto err_clear_drvdata;
667
error = input_register_device(ts->idev);
670
"Failed to register input device, err: %d\n", error);
671
goto err_remove_sysfs;
674
irq_set_irq_wake(spi->irq, 1);
678
sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
680
spi_set_drvdata(spi, NULL);
681
free_irq(spi->irq, ts);
683
input_free_device(input_dev);
688
static int __devexit tsc2005_remove(struct spi_device *spi)
690
struct tsc2005 *ts = spi_get_drvdata(spi);
692
sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group);
694
free_irq(ts->spi->irq, ts);
695
input_unregister_device(ts->idev);
698
spi_set_drvdata(spi, NULL);
702
#ifdef CONFIG_PM_SLEEP
703
static int tsc2005_suspend(struct device *dev)
705
struct spi_device *spi = to_spi_device(dev);
706
struct tsc2005 *ts = spi_get_drvdata(spi);
708
mutex_lock(&ts->mutex);
710
if (!ts->suspended && ts->opened)
711
__tsc2005_disable(ts);
713
ts->suspended = true;
715
mutex_unlock(&ts->mutex);
720
static int tsc2005_resume(struct device *dev)
722
struct spi_device *spi = to_spi_device(dev);
723
struct tsc2005 *ts = spi_get_drvdata(spi);
725
mutex_lock(&ts->mutex);
727
if (ts->suspended && ts->opened)
728
__tsc2005_enable(ts);
730
ts->suspended = false;
732
mutex_unlock(&ts->mutex);
738
static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume);
740
static struct spi_driver tsc2005_driver = {
743
.owner = THIS_MODULE,
744
.pm = &tsc2005_pm_ops,
746
.probe = tsc2005_probe,
747
.remove = __devexit_p(tsc2005_remove),
750
static int __init tsc2005_init(void)
752
return spi_register_driver(&tsc2005_driver);
754
module_init(tsc2005_init);
756
static void __exit tsc2005_exit(void)
758
spi_unregister_driver(&tsc2005_driver);
760
module_exit(tsc2005_exit);
762
MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
763
MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
764
MODULE_LICENSE("GPL");