--- /dev/null
+/*
+ * linux/drivers/mfd/ucb1x00-ts.c
+ *
+ * Copyright (C) 2001 Russell King, All Rights Reserved.
+ *
+ * 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/config.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/input.h>
+#include <linux/device.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+
+#include <asm/dma.h>
+#include <asm/semaphore.h>
+
+#include "ucb1x00.h"
+
+
+struct ucb1x00_ts {
+ struct input_dev idev;
+ struct ucb1x00 *ucb;
+
+ wait_queue_head_t irq_wait;
+ struct semaphore sem;
+ struct completion init_exit;
+ struct task_struct *rtask;
+ int use_count;
+ u16 x_res;
+ u16 y_res;
+
+ int restart:1;
+ int adcsync:1;
+};
+
+static int adcsync;
+
+static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
+{
+ input_report_abs(&ts->idev, ABS_X, x);
+ input_report_abs(&ts->idev, ABS_Y, y);
+ input_report_abs(&ts->idev, ABS_PRESSURE, pressure);
+ input_sync(&ts->idev);
+}
+
+static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
+{
+ input_report_abs(&ts->idev, ABS_PRESSURE, 0);
+ input_sync(&ts->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)
+{
+ 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)
+{
+ 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)
+{
+ 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);
+}
+
+/*
+ * 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;
+ struct task_struct *tsk = current;
+ DECLARE_WAITQUEUE(wait, tsk);
+ int valid;
+
+ ts->rtask = tsk;
+
+ daemonize("ktsd");
+ /* only want to receive SIGKILL */
+ allow_signal(SIGKILL);
+
+ /*
+ * We could run as a real-time thread. However, thus far
+ * this doesn't seem to be necessary.
+ */
+// tsk->policy = SCHED_FIFO;
+// tsk->rt_priority = 1;
+
+ complete(&ts->init_exit);
+
+ valid = 0;
+
+ add_wait_queue(&ts->irq_wait, &wait);
+ for (;;) {
+ unsigned int x, y, p, val;
+ signed long timeout;
+
+ ts->restart = 0;
+
+ 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);
+
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ schedule_timeout(HZ / 100);
+ if (signal_pending(tsk))
+ break;
+
+ ucb1x00_enable(ts->ucb);
+ val = ucb1x00_reg_read(ts->ucb, UCB_TS_CR);
+
+ if (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW)) {
+ set_task_state(tsk, TASK_INTERRUPTIBLE);
+
+ ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+ 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 (!ts->restart) {
+ ucb1x00_ts_evt_add(ts, p, x, y);
+ valid = 1;
+ }
+
+ set_task_state(tsk, TASK_INTERRUPTIBLE);
+ timeout = HZ / 100;
+ }
+
+ try_to_freeze();
+
+ schedule_timeout(timeout);
+ if (signal_pending(tsk))
+ break;
+ }
+
+ remove_wait_queue(&ts->irq_wait, &wait);
+
+ ts->rtask = NULL;
+ complete_and_exit(&ts->init_exit, 0);
+}
+
+/*
+ * We only detect touch screen _touches_ with this interrupt
+ * handler, and even then we just schedule our task.
+ */
+static void ucb1x00_ts_irq(int idx, void *id)
+{
+ struct ucb1x00_ts *ts = id;
+ ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+ wake_up(&ts->irq_wait);
+}
+
+static int ucb1x00_ts_open(struct input_dev *idev)
+{
+ struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
+ int ret = 0;
+
+ if (down_interruptible(&ts->sem))
+ return -EINTR;
+
+ if (ts->use_count++ != 0)
+ goto out;
+
+ if (ts->rtask)
+ panic("ucb1x00: rtask running?");
+
+ init_waitqueue_head(&ts->irq_wait);
+ ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, 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);
+
+ init_completion(&ts->init_exit);
+ ret = kernel_thread(ucb1x00_thread, ts, CLONE_KERNEL);
+ if (ret >= 0) {
+ wait_for_completion(&ts->init_exit);
+ ret = 0;
+ } else {
+ ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+ }
+
+ out:
+ if (ret)
+ ts->use_count--;
+ up(&ts->sem);
+ return ret;
+}
+
+/*
+ * Release touchscreen resources. Disable IRQs.
+ */
+static void ucb1x00_ts_close(struct input_dev *idev)
+{
+ struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
+
+ down(&ts->sem);
+ if (--ts->use_count == 0) {
+ if (ts->rtask) {
+ send_sig(SIGKILL, ts->rtask, 1);
+ wait_for_completion(&ts->init_exit);
+ }
+
+ ucb1x00_enable(ts->ucb);
+ ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+ ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
+ ucb1x00_disable(ts->ucb);
+ }
+ up(&ts->sem);
+}
+
+#ifdef CONFIG_PM
+static int ucb1x00_ts_resume(struct ucb1x00_dev *dev)
+{
+ struct ucb1x00_ts *ts = dev->priv;
+
+ if (ts->rtask != NULL) {
+ /*
+ * Restart the TS thread to ensure the
+ * TS interrupt mode is set up again
+ * after sleep.
+ */
+ ts->restart = 1;
+ wake_up(&ts->irq_wait);
+ }
+ return 0;
+}
+#else
+#define ucb1x00_ts_resume NULL
+#endif
+
+
+/*
+ * Initialisation.
+ */
+static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
+{
+ struct ucb1x00_ts *ts;
+
+ ts = kmalloc(sizeof(struct ucb1x00_ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ memset(ts, 0, sizeof(struct ucb1x00_ts));
+
+ ts->ucb = dev->ucb;
+ ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
+ init_MUTEX(&ts->sem);
+
+ ts->idev.name = "Touchscreen panel";
+ ts->idev.id.product = ts->ucb->id;
+ ts->idev.open = ucb1x00_ts_open;
+ ts->idev.close = ucb1x00_ts_close;
+
+ __set_bit(EV_ABS, ts->idev.evbit);
+ __set_bit(ABS_X, ts->idev.absbit);
+ __set_bit(ABS_Y, ts->idev.absbit);
+ __set_bit(ABS_PRESSURE, ts->idev.absbit);
+
+ input_register_device(&ts->idev);
+
+ dev->priv = ts;
+
+ return 0;
+}
+
+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,
+ .resume = ucb1x00_ts_resume,
+};
+
+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");
projects / linux-2.6 / commitdiff