/* * 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_relative( 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 umode_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); umode_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; if (!mutex_trylock(&ts->mutex)) { /* * If the mutex is taken, it means that disable or enable is in * progress. In that case just reschedule the work. If the work * is not needed, it will be canceled by disable. */ goto reschedule; } 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: mutex_unlock(&ts->mutex); reschedule: /* re-arm the watchdog */ schedule_delayed_work(&ts->esd_work, round_jiffies_relative( msecs_to_jiffies(ts->esd_timeout))); } 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 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 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 | IRQF_ONESHOT, "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; } irq_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 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 = tsc2005_remove, }; module_spi_driver(tsc2005_driver); MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>"); MODULE_DESCRIPTION("TSC2005 Touchscreen Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:tsc2005");