diff options
Diffstat (limited to 'drivers/mfd/ucb1x00-ts.c')
| -rw-r--r-- | drivers/mfd/ucb1x00-ts.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c new file mode 100644 index 000000000..1e0e20c0e --- /dev/null +++ b/drivers/mfd/ucb1x00-ts.c @@ -0,0 +1,448 @@ +/* + * Touchscreen driver for UCB1x00-based touchscreens + * + * Copyright (C) 2001 Russell King, All Rights Reserved. + * Copyright (C) 2005 Pavel Machek + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 21-Jan-2002 <jco@ict.es> : + * + * Added support for synchronous A/D mode. This mode is useful to + * avoid noise induced in the touchpanel by the LCD, provided that + * the UCB1x00 has a valid LCD sync signal routed to its ADCSYNC pin. + * It is important to note that the signal connected to the ADCSYNC + * pin should provide pulses even when the LCD is blanked, otherwise + * a pen touch needed to unblank the LCD will never be read. + */ +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/input.h> +#include <linux/device.h> +#include <linux/freezer.h> +#include <linux/slab.h> +#include <linux/kthread.h> +#include <linux/mfd/ucb1x00.h> + +#include <mach/collie.h> +#include <asm/mach-types.h> + + + +struct ucb1x00_ts { + struct input_dev *idev; + struct ucb1x00 *ucb; + + spinlock_t irq_lock; + unsigned irq_disabled; + wait_queue_head_t irq_wait; + struct task_struct *rtask; + u16 x_res; + u16 y_res; + + unsigned int adcsync:1; +}; + +static int adcsync; + +static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y) +{ + struct input_dev *idev = ts->idev; + + input_report_abs(idev, ABS_X, x); + input_report_abs(idev, ABS_Y, y); + input_report_abs(idev, ABS_PRESSURE, pressure); + input_report_key(idev, BTN_TOUCH, 1); + input_sync(idev); +} + +static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts) +{ + struct input_dev *idev = ts->idev; + + input_report_abs(idev, ABS_PRESSURE, 0); + input_report_key(idev, BTN_TOUCH, 0); + input_sync(idev); +} + +/* + * Switch to interrupt mode. + */ +static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | + UCB_TS_CR_MODE_INT); +} + +/* + * Switch to pressure mode, and read pressure. We don't need to wait + * here, since both plates are being driven. + */ +static inline unsigned int ucb1x00_ts_read_pressure(struct ucb1x00_ts *ts) +{ + if (machine_is_collie()) { + ucb1x00_io_write(ts->ucb, COLLIE_TC35143_GPIO_TBL_CHK, 0); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSPX_POW | UCB_TS_CR_TSMX_POW | + UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); + + udelay(55); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_AD2, ts->adcsync); + } else { + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); + } +} + +/* + * Switch to X position mode and measure Y plate. We switch the plate + * configuration in pressure mode, then switch to position mode. This + * gives a faster response time. Even so, we need to wait about 55us + * for things to stabilise. + */ +static inline unsigned int ucb1x00_ts_read_xpos(struct ucb1x00_ts *ts) +{ + if (machine_is_collie()) + ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); + else { + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + } + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); + + udelay(55); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPY, ts->adcsync); +} + +/* + * Switch to Y position mode and measure X plate. We switch the plate + * configuration in pressure mode, then switch to position mode. This + * gives a faster response time. Even so, we need to wait about 55us + * for things to stabilise. + */ +static inline unsigned int ucb1x00_ts_read_ypos(struct ucb1x00_ts *ts) +{ + if (machine_is_collie()) + ucb1x00_io_write(ts->ucb, 0, COLLIE_TC35143_GPIO_TBL_CHK); + else { + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + } + + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA); + + udelay(55); + + return ucb1x00_adc_read(ts->ucb, UCB_ADC_INP_TSPX, ts->adcsync); +} + +/* + * Switch to X plate resistance mode. Set MX to ground, PX to + * supply. Measure current. + */ +static inline unsigned int ucb1x00_ts_read_xres(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); +} + +/* + * Switch to Y plate resistance mode. Set MY to ground, PY to + * supply. Measure current. + */ +static inline unsigned int ucb1x00_ts_read_yres(struct ucb1x00_ts *ts) +{ + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, + UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW | + UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA); + return ucb1x00_adc_read(ts->ucb, 0, ts->adcsync); +} + +static inline int ucb1x00_ts_pen_down(struct ucb1x00_ts *ts) +{ + unsigned int val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR); + + if (machine_is_collie()) + return (!(val & (UCB_TS_CR_TSPX_LOW))); + else + return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)); +} + +/* + * This is a RT kernel thread that handles the ADC accesses + * (mainly so we can use semaphores in the UCB1200 core code + * to serialise accesses to the ADC). + */ +static int ucb1x00_thread(void *_ts) +{ + struct ucb1x00_ts *ts = _ts; + DECLARE_WAITQUEUE(wait, current); + bool frozen, ignore = false; + int valid = 0; + + set_freezable(); + add_wait_queue(&ts->irq_wait, &wait); + while (!kthread_freezable_should_stop(&frozen)) { + unsigned int x, y, p; + signed long timeout; + + if (frozen) + ignore = true; + + ucb1x00_adc_enable(ts->ucb); + + x = ucb1x00_ts_read_xpos(ts); + y = ucb1x00_ts_read_ypos(ts); + p = ucb1x00_ts_read_pressure(ts); + + /* + * Switch back to interrupt mode. + */ + ucb1x00_ts_mode_int(ts); + ucb1x00_adc_disable(ts->ucb); + + msleep(10); + + ucb1x00_enable(ts->ucb); + + + if (ucb1x00_ts_pen_down(ts)) { + set_current_state(TASK_INTERRUPTIBLE); + + spin_lock_irq(&ts->irq_lock); + if (ts->irq_disabled) { + ts->irq_disabled = 0; + enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX); + } + spin_unlock_irq(&ts->irq_lock); + ucb1x00_disable(ts->ucb); + + /* + * If we spat out a valid sample set last time, + * spit out a "pen off" sample here. + */ + if (valid) { + ucb1x00_ts_event_release(ts); + valid = 0; + } + + timeout = MAX_SCHEDULE_TIMEOUT; + } else { + ucb1x00_disable(ts->ucb); + + /* + * Filtering is policy. Policy belongs in user + * space. We therefore leave it to user space + * to do any filtering they please. + */ + if (!ignore) { + ucb1x00_ts_evt_add(ts, p, x, y); + valid = 1; + } + + set_current_state(TASK_INTERRUPTIBLE); + timeout = HZ / 100; + } + + schedule_timeout(timeout); + } + + remove_wait_queue(&ts->irq_wait, &wait); + + ts->rtask = NULL; + return 0; +} + +/* + * We only detect touch screen _touches_ with this interrupt + * handler, and even then we just schedule our task. + */ +static irqreturn_t ucb1x00_ts_irq(int irq, void *id) +{ + struct ucb1x00_ts *ts = id; + + spin_lock(&ts->irq_lock); + ts->irq_disabled = 1; + disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX); + spin_unlock(&ts->irq_lock); + wake_up(&ts->irq_wait); + + return IRQ_HANDLED; +} + +static int ucb1x00_ts_open(struct input_dev *idev) +{ + struct ucb1x00_ts *ts = input_get_drvdata(idev); + unsigned long flags = 0; + int ret = 0; + + BUG_ON(ts->rtask); + + if (machine_is_collie()) + flags = IRQF_TRIGGER_RISING; + else + flags = IRQF_TRIGGER_FALLING; + + ts->irq_disabled = 0; + + init_waitqueue_head(&ts->irq_wait); + ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq, + flags, "ucb1x00-ts", ts); + if (ret < 0) + goto out; + + /* + * If we do this at all, we should allow the user to + * measure and read the X and Y resistance at any time. + */ + ucb1x00_adc_enable(ts->ucb); + ts->x_res = ucb1x00_ts_read_xres(ts); + ts->y_res = ucb1x00_ts_read_yres(ts); + ucb1x00_adc_disable(ts->ucb); + + ts->rtask = kthread_run(ucb1x00_thread, ts, "ktsd"); + if (!IS_ERR(ts->rtask)) { + ret = 0; + } else { + free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts); + ts->rtask = NULL; + ret = -EFAULT; + } + + out: + return ret; +} + +/* + * Release touchscreen resources. Disable IRQs. + */ +static void ucb1x00_ts_close(struct input_dev *idev) +{ + struct ucb1x00_ts *ts = input_get_drvdata(idev); + + if (ts->rtask) + kthread_stop(ts->rtask); + + ucb1x00_enable(ts->ucb); + free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts); + ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0); + ucb1x00_disable(ts->ucb); +} + + +/* + * Initialisation. + */ +static int ucb1x00_ts_add(struct ucb1x00_dev *dev) +{ + struct ucb1x00_ts *ts; + struct input_dev *idev; + int err; + + ts = kzalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL); + idev = input_allocate_device(); + if (!ts || !idev) { + err = -ENOMEM; + goto fail; + } + + ts->ucb = dev->ucb; + ts->idev = idev; + ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC; + spin_lock_init(&ts->irq_lock); + + idev->name = "Touchscreen panel"; + idev->id.product = ts->ucb->id; + idev->open = ucb1x00_ts_open; + idev->close = ucb1x00_ts_close; + idev->dev.parent = &ts->ucb->dev; + + idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY); + idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); + + input_set_drvdata(idev, ts); + + ucb1x00_adc_enable(ts->ucb); + ts->x_res = ucb1x00_ts_read_xres(ts); + ts->y_res = ucb1x00_ts_read_yres(ts); + ucb1x00_adc_disable(ts->ucb); + + input_set_abs_params(idev, ABS_X, 0, ts->x_res, 0, 0); + input_set_abs_params(idev, ABS_Y, 0, ts->y_res, 0, 0); + input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0); + + err = input_register_device(idev); + if (err) + goto fail; + + dev->priv = ts; + + return 0; + + fail: + input_free_device(idev); + kfree(ts); + return err; +} + +static void ucb1x00_ts_remove(struct ucb1x00_dev *dev) +{ + struct ucb1x00_ts *ts = dev->priv; + + input_unregister_device(ts->idev); + kfree(ts); +} + +static struct ucb1x00_driver ucb1x00_ts_driver = { + .add = ucb1x00_ts_add, + .remove = ucb1x00_ts_remove, +}; + +static int __init ucb1x00_ts_init(void) +{ + return ucb1x00_register_driver(&ucb1x00_ts_driver); +} + +static void __exit ucb1x00_ts_exit(void) +{ + ucb1x00_unregister_driver(&ucb1x00_ts_driver); +} + +module_param(adcsync, int, 0444); +module_init(ucb1x00_ts_init); +module_exit(ucb1x00_ts_exit); + +MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); +MODULE_DESCRIPTION("UCB1x00 touchscreen driver"); +MODULE_LICENSE("GPL"); |