/* * TSC2005 touchscreen driver * * Copyright (C) 2006-2010 Nokia Corporation * * Author: Lauri Leukkunen * based on TSC2301 driver by Klaus K. Pedersen * * 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 #include #include #include #include #include #include #include /* * 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; struct timer_list penup_timer; struct work_struct penup_work; unsigned int esd_timeout; struct timer_list esd_timer; struct work_struct esd_work; unsigned int x_plate_ohm; bool disabled; unsigned int disable_depth; unsigned int pen_down; void (*set_reset)(bool enable); }; static void tsc2005_cmd(struct tsc2005 *ts, u8 cmd) { u8 tx; struct spi_message msg; struct spi_transfer xfer = { 0 }; tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd; xfer.tx_buf = &tx; xfer.rx_buf = NULL; xfer.len = 1; xfer.bits_per_word = 8; spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); spi_sync(ts->spi, &msg); } static void tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value) { u32 tx; struct spi_message msg; struct spi_transfer xfer = { 0 }; tx = (reg | TSC2005_REG_PND0) << 16; tx |= value; xfer.tx_buf = &tx; xfer.rx_buf = NULL; xfer.len = 4; xfer.bits_per_word = 24; spi_message_init(&msg); spi_message_add_tail(&xfer, &msg); spi_sync(ts->spi, &msg); } static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last) { 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 void tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value) { struct spi_message msg; struct tsc2005_spi_rd spi_rd = { { 0 }, 0, 0 }; tsc2005_setup_read(&spi_rd, reg, 1); spi_message_init(&msg); spi_message_add_tail(&spi_rd.spi_xfer, &msg); spi_sync(ts->spi, &msg); *value = spi_rd.spi_rx; } 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 = 1; } } else { input_report_abs(ts->idev, ABS_PRESSURE, 0); if (ts->pen_down) { input_report_key(ts->idev, BTN_TOUCH, 0); ts->pen_down = 0; } } input_sync(ts->idev); dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y, pressure); } static irqreturn_t tsc2005_irq_handler(int irq, void *dev_id) { struct tsc2005 *ts = dev_id; /* update the penup timer only if it's pending */ mod_timer_pending(&ts->penup_timer, jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS)); return IRQ_WAKE_THREAD; } static irqreturn_t tsc2005_irq_thread(int irq, void *_ts) { struct tsc2005 *ts = _ts; unsigned int pressure; u32 x; u32 y; u32 z1; u32 z2; mutex_lock(&ts->mutex); if (unlikely(ts->disable_depth)) goto out; /* read the coordinates */ spi_sync(ts->spi, &ts->spi_read_msg); 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 coords 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; tsc2005_update_pen_state(ts, x, y, pressure); /* set the penup timer */ mod_timer(&ts->penup_timer, jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS)); if (!ts->esd_timeout) goto out; /* update the watchdog timer */ mod_timer(&ts->esd_timer, round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout))); out: mutex_unlock(&ts->mutex); return IRQ_HANDLED; } static void tsc2005_penup_timer(unsigned long data) { struct tsc2005 *ts = (struct tsc2005 *)data; schedule_work(&ts->penup_work); } static void tsc2005_penup_work(struct work_struct *work) { struct tsc2005 *ts = container_of(work, struct tsc2005, penup_work); mutex_lock(&ts->mutex); tsc2005_update_pen_state(ts, 0, 0, 0); mutex_unlock(&ts->mutex); } 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 mutex held */ static void tsc2005_disable(struct tsc2005 *ts) { if (ts->disable_depth++ != 0) return; disable_irq(ts->spi->irq); if (ts->esd_timeout) del_timer_sync(&ts->esd_timer); del_timer_sync(&ts->penup_timer); tsc2005_stop_scan(ts); } /* must be called with mutex held */ static void tsc2005_enable(struct tsc2005 *ts) { if (--ts->disable_depth != 0) return; tsc2005_start_scan(ts); enable_irq(ts->spi->irq); if (!ts->esd_timeout) return; mod_timer(&ts->esd_timer, round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout))); } static ssize_t tsc2005_disable_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); return sprintf(buf, "%u\n", ts->disabled); } static ssize_t tsc2005_disable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct spi_device *spi = to_spi_device(dev); struct tsc2005 *ts = spi_get_drvdata(spi); unsigned long res; int i; if (strict_strtoul(buf, 10, &res) < 0) return -EINVAL; i = res ? 1 : 0; mutex_lock(&ts->mutex); if (i == ts->disabled) goto out; ts->disabled = i; if (i) tsc2005_disable(ts); else tsc2005_enable(ts); out: mutex_unlock(&ts->mutex); return count; } static DEVICE_ATTR(disable, 0664, tsc2005_disable_show, tsc2005_disable_store); 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; unsigned int result; if (!ts->set_reset) { dev_warn(&ts->spi->dev, "unable to selftest: no reset function\n"); result = 0; goto out; } mutex_lock(&ts->mutex); /* * Test TSC2005 communications via temp high register. */ tsc2005_disable(ts); result = 1; tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig); temp_high_test = (temp_high_orig - 1) & MAX_12BIT; tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test); tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high); if (temp_high != temp_high_test) { dev_warn(dev, "selftest failed: %d != %d\n", temp_high, temp_high_test); result = 0; } /* hardware reset */ ts->set_reset(0); usleep_range(100, 500); /* only 10us required */ ts->set_reset(1); tsc2005_enable(ts); /* test that the reset really happened */ tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high); if (temp_high != temp_high_orig) { dev_warn(dev, "selftest failed after reset: %d != %d\n", temp_high, temp_high_orig); result = 0; } mutex_unlock(&ts->mutex); out: return sprintf(buf, "%u\n", result); } static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL); static void tsc2005_esd_timer(unsigned long data) { struct tsc2005 *ts = (struct tsc2005 *)data; schedule_work(&ts->esd_work); } static void tsc2005_esd_work(struct work_struct *work) { struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work); u16 r; mutex_lock(&ts->mutex); if (ts->disable_depth) goto out; /* * If we cannot read our known value from configuration register 0 then * reset the controller as if from power-up and start scanning again. */ tsc2005_read(ts, TSC2005_REG_CFR0, &r); if ((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK) { dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n"); ts->set_reset(0); tsc2005_update_pen_state(ts, 0, 0, 0); usleep_range(100, 500); /* only 10us required */ ts->set_reset(1); tsc2005_start_scan(ts); } /* re-arm the watchdog */ mod_timer(&ts->esd_timer, round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout))); out: mutex_unlock(&ts->mutex); } static void __devinit tsc2005_setup_spi_xfer(struct tsc2005 *ts) { tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, 0); tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, 0); tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, 0); tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, 1); 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 struct attribute *tsc2005_attrs[] = { &dev_attr_disable.attr, &dev_attr_selftest.attr, NULL }; static struct attribute_group tsc2005_attr_group = { .attrs = tsc2005_attrs, }; static int __devinit tsc2005_setup(struct tsc2005 *ts, struct tsc2005_platform_data *pdata) { int r; int fudge_x; int fudge_y; int fudge_p; int p_max; int x_max; int y_max; mutex_init(&ts->mutex); tsc2005_setup_spi_xfer(ts); init_timer(&ts->penup_timer); setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts); INIT_WORK(&ts->penup_work, tsc2005_penup_work); fudge_x = pdata->ts_x_fudge ? : 4; fudge_y = pdata->ts_y_fudge ? : 8; fudge_p = pdata->ts_pressure_fudge ? : 2; x_max = pdata->ts_x_max ? : MAX_12BIT; y_max = pdata->ts_y_max ? : MAX_12BIT; p_max = pdata->ts_pressure_max ? : MAX_12BIT; ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280; ts->esd_timeout = pdata->esd_timeout_ms; ts->set_reset = pdata->set_reset; ts->idev = input_allocate_device(); if (ts->idev == NULL) return -ENOMEM; ts->idev->name = "TSC2005 touchscreen"; snprintf(ts->phys, sizeof(ts->phys), "%s/input-ts", dev_name(&ts->spi->dev)); ts->idev->phys = ts->phys; ts->idev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY); ts->idev->absbit[0] = BIT(ABS_X) | BIT(ABS_Y) | BIT(ABS_PRESSURE); ts->idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); input_set_abs_params(ts->idev, ABS_X, 0, x_max, fudge_x, 0); input_set_abs_params(ts->idev, ABS_Y, 0, y_max, fudge_y, 0); input_set_abs_params(ts->idev, ABS_PRESSURE, 0, p_max, fudge_p, 0); r = request_threaded_irq(ts->spi->irq, tsc2005_irq_handler, tsc2005_irq_thread, IRQF_TRIGGER_RISING, "tsc2005", ts); if (r) { dev_err(&ts->spi->dev, "request_threaded_irq(): %d\n", r); goto err1; } set_irq_wake(ts->spi->irq, 1); r = input_register_device(ts->idev); if (r) { dev_err(&ts->spi->dev, "input_register_device(): %d\n", r); goto err2; } r = sysfs_create_group(&ts->spi->dev.kobj, &tsc2005_attr_group); if (r) dev_warn(&ts->spi->dev, "sysfs entry creation failed: %d\n", r); tsc2005_start_scan(ts); if (!ts->esd_timeout || !ts->set_reset) goto done; /* start the optional ESD watchdog */ setup_timer(&ts->esd_timer, tsc2005_esd_timer, (unsigned long)ts); INIT_WORK(&ts->esd_work, tsc2005_esd_work); mod_timer(&ts->esd_timer, round_jiffies(jiffies + msecs_to_jiffies(ts->esd_timeout))); done: return 0; err2: free_irq(ts->spi->irq, ts); err1: input_free_device(ts->idev); return r; } static int __devinit tsc2005_probe(struct spi_device *spi) { struct tsc2005_platform_data *pdata = spi->dev.platform_data; struct tsc2005 *ts; int r; if (spi->irq < 0) { dev_dbg(&spi->dev, "no irq\n"); return -ENODEV; } if (!pdata) { dev_dbg(&spi->dev, "no platform data\n"); return -ENODEV; } ts = kzalloc(sizeof(*ts), GFP_KERNEL); if (ts == NULL) return -ENOMEM; spi_set_drvdata(spi, ts); ts->spi = spi; spi->dev.power.power_state = PMSG_ON; spi->mode = SPI_MODE_0; spi->bits_per_word = 8; if (!spi->max_speed_hz) spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ; spi_setup(spi); r = tsc2005_setup(ts, pdata); if (r) kfree(ts); return r; } static int __devexit tsc2005_remove(struct spi_device *spi) { struct tsc2005 *ts = spi_get_drvdata(spi); mutex_lock(&ts->mutex); tsc2005_disable(ts); mutex_unlock(&ts->mutex); if (ts->esd_timeout) del_timer_sync(&ts->esd_timer); del_timer_sync(&ts->penup_timer); flush_work(&ts->esd_work); flush_work(&ts->penup_work); sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group); free_irq(ts->spi->irq, ts); input_unregister_device(ts->idev); kfree(ts); 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); tsc2005_disable(ts); 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); tsc2005_enable(ts); 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 "); MODULE_LICENSE("GPL");