diff options
Diffstat (limited to 'drivers/input/touchscreen/tsc2005.c')
| -rw-r--r-- | drivers/input/touchscreen/tsc2005.c | 756 |
1 files changed, 756 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/tsc2005.c b/drivers/input/touchscreen/tsc2005.c new file mode 100644 index 0000000..8742061 --- /dev/null +++ b/drivers/input/touchscreen/tsc2005.c @@ -0,0 +1,756 @@ +/* + * 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->dev, "point(%4d,%4d), pressure (%4d)\n", x, y, + pressure); +} + +static irqreturn_t tsc2005_irq_thread(int irq, void *_ts) +{ + struct tsc2005 *ts = _ts; + unsigned long flags; + unsigned int pressure; + u32 x, y; + u32 z1, z2; + int error; + + /* read the coordinates */ + error = spi_sync(ts->spi, &ts->spi_read_msg); + if (unlikely(error)) + goto out; + + x = ts->spi_x.spi_rx; + y = ts->spi_y.spi_rx; + z1 = ts->spi_z1.spi_rx; + z2 = ts->spi_z2.spi_rx; + + /* validate position */ + if (unlikely(x > MAX_12BIT || y > MAX_12BIT)) + goto out; + + /* Skip reading if the pressure components are out of range */ + if (unlikely(z1 == 0 || z2 > MAX_12BIT || z1 >= z2)) + goto out; + + /* + * Skip point if this is a pen down with the exact same values as + * the value before pen-up - that implies SPI fed us stale data + */ + if (!ts->pen_down && + ts->in_x == x && ts->in_y == y && + ts->in_z1 == z1 && ts->in_z2 == z2) { + goto out; + } + + /* + * At this point we are happy we have a valid and useful reading. + * Remember it for later comparisons. We may now begin downsampling. + */ + ts->in_x = x; + ts->in_y = y; + ts->in_z1 = z1; + ts->in_z2 = z2; + + /* Compute touch pressure resistance using equation #1 */ + pressure = x * (z2 - z1) / z1; + pressure = pressure * ts->x_plate_ohm / 4096; + if (unlikely(pressure > MAX_12BIT)) + goto out; + + spin_lock_irqsave(&ts->lock, flags); + + tsc2005_update_pen_state(ts, x, y, pressure); + mod_timer(&ts->penup_timer, + jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS)); + + spin_unlock_irqrestore(&ts->lock, flags); + + ts->last_valid_interrupt = jiffies; +out: + return IRQ_HANDLED; +} + +static void tsc2005_penup_timer(unsigned long data) +{ + struct tsc2005 *ts = (struct tsc2005 *)data; + unsigned long flags; + + spin_lock_irqsave(&ts->lock, flags); + tsc2005_update_pen_state(ts, 0, 0, 0); + spin_unlock_irqrestore(&ts->lock, flags); +} + +static void tsc2005_start_scan(struct tsc2005 *ts) +{ + tsc2005_write(ts, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE); + tsc2005_write(ts, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE); + tsc2005_write(ts, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE); + tsc2005_cmd(ts, TSC2005_CMD_NORMAL); +} + +static void tsc2005_stop_scan(struct tsc2005 *ts) +{ + tsc2005_cmd(ts, TSC2005_CMD_STOP); +} + +/* must be called with ts->mutex held */ +static void __tsc2005_disable(struct tsc2005 *ts) +{ + tsc2005_stop_scan(ts); + + disable_irq(ts->spi->irq); + del_timer_sync(&ts->penup_timer); + + cancel_delayed_work_sync(&ts->esd_work); + + enable_irq(ts->spi->irq); +} + +/* must be called with ts->mutex held */ +static void __tsc2005_enable(struct tsc2005 *ts) +{ + tsc2005_start_scan(ts); + + if (ts->esd_timeout && ts->set_reset) { + ts->last_valid_interrupt = jiffies; + schedule_delayed_work(&ts->esd_work, + round_jiffies(jiffies + + msecs_to_jiffies(ts->esd_timeout))); + } + +} + +static ssize_t tsc2005_selftest_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct spi_device *spi = to_spi_device(dev); + struct tsc2005 *ts = spi_get_drvdata(spi); + u16 temp_high; + u16 temp_high_orig; + u16 temp_high_test; + bool success = true; + int error; + + mutex_lock(&ts->mutex); + + /* + * Test TSC2005 communications via temp high register. + */ + __tsc2005_disable(ts); + + error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig); + if (error) { + dev_warn(dev, "selftest failed: read error %d\n", error); + success = false; + goto out; + } + + temp_high_test = (temp_high_orig - 1) & MAX_12BIT; + + error = tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test); + if (error) { + dev_warn(dev, "selftest failed: write error %d\n", error); + success = false; + goto out; + } + + error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high); + if (error) { + dev_warn(dev, "selftest failed: read error %d after write\n", + error); + success = false; + goto out; + } + + if (temp_high != temp_high_test) { + dev_warn(dev, "selftest failed: %d != %d\n", + temp_high, temp_high_test); + success = false; + } + + /* hardware reset */ + ts->set_reset(false); + usleep_range(100, 500); /* only 10us required */ + ts->set_reset(true); + + if (!success) + goto out; + + /* test that the reset really happened */ + error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high); + if (error) { + dev_warn(dev, "selftest failed: read error %d after reset\n", + error); + success = false; + goto out; + } + + if (temp_high != temp_high_orig) { + dev_warn(dev, "selftest failed after reset: %d != %d\n", + temp_high, temp_high_orig); + success = false; + } + +out: + __tsc2005_enable(ts); + mutex_unlock(&ts->mutex); + + return sprintf(buf, "%d\n", success); +} + +static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL); + +static struct attribute *tsc2005_attrs[] = { + &dev_attr_selftest.attr, + NULL +}; + +static mode_t tsc2005_attr_is_visible(struct kobject *kobj, + struct attribute *attr, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct spi_device *spi = to_spi_device(dev); + struct tsc2005 *ts = spi_get_drvdata(spi); + mode_t mode = attr->mode; + + if (attr == &dev_attr_selftest.attr) { + if (!ts->set_reset) + mode = 0; + } + + return mode; +} + +static const struct attribute_group tsc2005_attr_group = { + .is_visible = tsc2005_attr_is_visible, + .attrs = tsc2005_attrs, +}; + +static void tsc2005_esd_work(struct work_struct *work) +{ + struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work.work); + int error; + u16 r; + + mutex_lock(&ts->mutex); + + if (time_is_after_jiffies(ts->last_valid_interrupt + + msecs_to_jiffies(ts->esd_timeout))) + goto out; + + /* We should be able to read register without disabling interrupts. */ + error = tsc2005_read(ts, TSC2005_REG_CFR0, &r); + if (!error && + !((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK)) { + goto out; + } + + /* + * If we could not read our known value from configuration register 0 + * then we should reset the controller as if from power-up and start + * scanning again. + */ + dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n"); + + disable_irq(ts->spi->irq); + del_timer_sync(&ts->penup_timer); + + tsc2005_update_pen_state(ts, 0, 0, 0); + + ts->set_reset(false); + usleep_range(100, 500); /* only 10us required */ + ts->set_reset(true); + + enable_irq(ts->spi->irq); + tsc2005_start_scan(ts); + +out: + /* re-arm the watchdog */ + schedule_delayed_work(&ts->esd_work, + round_jiffies(jiffies + + msecs_to_jiffies(ts->esd_timeout))); + mutex_unlock(&ts->mutex); +} + +static int tsc2005_open(struct input_dev *input) +{ + struct tsc2005 *ts = input_get_drvdata(input); + + mutex_lock(&ts->mutex); + + if (!ts->suspended) + __tsc2005_enable(ts); + + ts->opened = true; + + mutex_unlock(&ts->mutex); + + return 0; +} + +static void tsc2005_close(struct input_dev *input) +{ + struct tsc2005 *ts = input_get_drvdata(input); + + mutex_lock(&ts->mutex); + + if (!ts->suspended) + __tsc2005_disable(ts); + + ts->opened = false; + + mutex_unlock(&ts->mutex); +} + +static void __devinit tsc2005_setup_spi_xfer(struct tsc2005 *ts) +{ + tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, false); + tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, false); + tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, false); + tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, true); + + spi_message_init(&ts->spi_read_msg); + spi_message_add_tail(&ts->spi_x.spi_xfer, &ts->spi_read_msg); + spi_message_add_tail(&ts->spi_y.spi_xfer, &ts->spi_read_msg); + spi_message_add_tail(&ts->spi_z1.spi_xfer, &ts->spi_read_msg); + spi_message_add_tail(&ts->spi_z2.spi_xfer, &ts->spi_read_msg); +} + +static int __devinit tsc2005_probe(struct spi_device *spi) +{ + const struct tsc2005_platform_data *pdata = spi->dev.platform_data; + struct tsc2005 *ts; + struct input_dev *input_dev; + unsigned int max_x, max_y, max_p; + unsigned int fudge_x, fudge_y, fudge_p; + int error; + + if (!pdata) { + dev_dbg(&spi->dev, "no platform data\n"); + return -ENODEV; + } + + fudge_x = pdata->ts_x_fudge ? : 4; + fudge_y = pdata->ts_y_fudge ? : 8; + fudge_p = pdata->ts_pressure_fudge ? : 2; + max_x = pdata->ts_x_max ? : MAX_12BIT; + max_y = pdata->ts_y_max ? : MAX_12BIT; + max_p = pdata->ts_pressure_max ? : MAX_12BIT; + + if (spi->irq <= 0) { + dev_dbg(&spi->dev, "no irq\n"); + return -ENODEV; + } + + spi->mode = SPI_MODE_0; + spi->bits_per_word = 8; + if (!spi->max_speed_hz) + spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ; + + error = spi_setup(spi); + if (error) + return error; + + ts = kzalloc(sizeof(*ts), GFP_KERNEL); + input_dev = input_allocate_device(); + if (!ts || !input_dev) { + error = -ENOMEM; + goto err_free_mem; + } + + ts->spi = spi; + ts->idev = input_dev; + + ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280; + ts->esd_timeout = pdata->esd_timeout_ms; + ts->set_reset = pdata->set_reset; + + mutex_init(&ts->mutex); + + spin_lock_init(&ts->lock); + setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts); + + INIT_DELAYED_WORK(&ts->esd_work, tsc2005_esd_work); + + tsc2005_setup_spi_xfer(ts); + + snprintf(ts->phys, sizeof(ts->phys), + "%s/input-ts", dev_name(&spi->dev)); + + input_dev->name = "TSC2005 touchscreen"; + input_dev->phys = ts->phys; + input_dev->id.bustype = BUS_SPI; + input_dev->dev.parent = &spi->dev; + input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY); + input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + + input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0); + input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0); + input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0); + + input_dev->open = tsc2005_open; + input_dev->close = tsc2005_close; + + input_set_drvdata(input_dev, ts); + + /* Ensure the touchscreen is off */ + tsc2005_stop_scan(ts); + + error = request_threaded_irq(spi->irq, NULL, tsc2005_irq_thread, + IRQF_TRIGGER_RISING, "tsc2005", ts); + if (error) { + dev_err(&spi->dev, "Failed to request irq, err: %d\n", error); + goto err_free_mem; + } + + spi_set_drvdata(spi, ts); + error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group); + if (error) { + dev_err(&spi->dev, + "Failed to create sysfs attributes, err: %d\n", error); + goto err_clear_drvdata; + } + + error = input_register_device(ts->idev); + if (error) { + dev_err(&spi->dev, + "Failed to register input device, err: %d\n", error); + goto err_remove_sysfs; + } + + set_irq_wake(spi->irq, 1); + return 0; + +err_remove_sysfs: + sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group); +err_clear_drvdata: + spi_set_drvdata(spi, NULL); + free_irq(spi->irq, ts); +err_free_mem: + input_free_device(input_dev); + kfree(ts); + return error; +} + +static int __devexit tsc2005_remove(struct spi_device *spi) +{ + struct tsc2005 *ts = spi_get_drvdata(spi); + + sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group); + + free_irq(ts->spi->irq, ts); + input_unregister_device(ts->idev); + kfree(ts); + + spi_set_drvdata(spi, NULL); + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int tsc2005_suspend(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + struct tsc2005 *ts = spi_get_drvdata(spi); + + mutex_lock(&ts->mutex); + + if (!ts->suspended && ts->opened) + __tsc2005_disable(ts); + + ts->suspended = true; + + mutex_unlock(&ts->mutex); + + return 0; +} + +static int tsc2005_resume(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + struct tsc2005 *ts = spi_get_drvdata(spi); + + mutex_lock(&ts->mutex); + + if (ts->suspended && ts->opened) + __tsc2005_enable(ts); + + ts->suspended = false; + + mutex_unlock(&ts->mutex); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume); + +static struct spi_driver tsc2005_driver = { + .driver = { + .name = "tsc2005", + .owner = THIS_MODULE, + .pm = &tsc2005_pm_ops, + }, + .probe = tsc2005_probe, + .remove = __devexit_p(tsc2005_remove), +}; + +static int __init tsc2005_init(void) +{ + return spi_register_driver(&tsc2005_driver); +} +module_init(tsc2005_init); + +static void __exit tsc2005_exit(void) +{ + spi_unregister_driver(&tsc2005_driver); +} +module_exit(tsc2005_exit); + +MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>"); +MODULE_DESCRIPTION("TSC2005 Touchscreen Driver"); +MODULE_LICENSE("GPL"); |