ucb1x00-ts.c
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上传日期:2013-02-24
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- /*
- * linux/drivers/misc/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/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/pm.h>
- #include <asm/dma.h>
- #include <asm/semaphore.h>
- #include "ucb1x00.h"
- /*
- * Define this if you want the UCB1x00 stuff to talk to the input layer
- */
- #ifdef CONFIG_INPUT
- #define USE_INPUT
- #else
- #undef USE_INPUT
- #endif
- #ifndef USE_INPUT
- #include <linux/fs.h>
- #include <linux/miscdevice.h>
- #include <linux/poll.h>
- /*
- * This structure is nonsense - millisecs is not very useful
- * since the field size is too small. Also, we SHOULD NOT
- * be exposing jiffies to user space directly.
- */
- struct ts_event {
- u16 pressure;
- u16 x;
- u16 y;
- u16 pad;
- struct timeval stamp;
- };
- #define NR_EVENTS 16
- #else
- #include <linux/input.h>
- #endif
- struct ucb1x00_ts {
- #ifdef USE_INPUT
- struct input_dev idev;
- #endif
- struct ucb1x00 *ucb;
- #ifdef CONFIG_PM
- struct pm_dev *pmdev;
- #endif
- 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;
- #ifndef USE_INPUT
- struct fasync_struct *fasync;
- wait_queue_head_t read_wait;
- u8 evt_head;
- u8 evt_tail;
- struct ts_event events[NR_EVENTS];
- #endif
- int restart:1;
- int adcsync:1;
- };
- static struct ucb1x00_ts ucbts;
- static int adcsync = UCB_NOSYNC;
- static int ucb1x00_ts_startup(struct ucb1x00_ts *ts);
- static void ucb1x00_ts_shutdown(struct ucb1x00_ts *ts);
- #ifndef USE_INPUT
- #define ucb1x00_ts_evt_pending(ts) ((volatile u8)(ts)->evt_head != (ts)->evt_tail)
- #define ucb1x00_ts_evt_get(ts) ((ts)->events + (ts)->evt_tail)
- #define ucb1x00_ts_evt_pull(ts) ((ts)->evt_tail = ((ts)->evt_tail + 1) & (NR_EVENTS - 1))
- #define ucb1x00_ts_evt_clear(ts) ((ts)->evt_head = (ts)->evt_tail = 0)
- static inline void ucb1x00_ts_evt_add(struct ucb1x00_ts *ts, u16 pressure, u16 x, u16 y)
- {
- int next_head;
- next_head = (ts->evt_head + 1) & (NR_EVENTS - 1);
- if (next_head != ts->evt_tail) {
- ts->events[ts->evt_head].pressure = pressure;
- ts->events[ts->evt_head].x = x;
- ts->events[ts->evt_head].y = y;
- do_gettimeofday(&ts->events[ts->evt_head].stamp);
- ts->evt_head = next_head;
- if (ts->fasync)
- kill_fasync(&ts->fasync, SIGIO, POLL_IN);
- wake_up_interruptible(&ts->read_wait);
- }
- }
- static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
- {
- ucb1x00_ts_evt_add(ts, 0, 0, 0);
- }
- /*
- * User space driver interface.
- */
- static ssize_t
- ucb1x00_ts_read(struct file *filp, char *buffer, size_t count, loff_t *ppos)
- {
- DECLARE_WAITQUEUE(wait, current);
- struct ucb1x00_ts *ts = filp->private_data;
- char *ptr = buffer;
- int err = 0;
- add_wait_queue(&ts->read_wait, &wait);
- while (count >= sizeof(struct ts_event)) {
- err = -ERESTARTSYS;
- if (signal_pending(current))
- break;
- if (ucb1x00_ts_evt_pending(ts)) {
- struct ts_event *evt = ucb1x00_ts_evt_get(ts);
- err = copy_to_user(ptr, evt, sizeof(struct ts_event));
- ucb1x00_ts_evt_pull(ts);
- if (err)
- break;
- ptr += sizeof(struct ts_event);
- count -= sizeof(struct ts_event);
- continue;
- }
- set_current_state(TASK_INTERRUPTIBLE);
- err = -EAGAIN;
- if (filp->f_flags & O_NONBLOCK)
- break;
- schedule();
- }
- current->state = TASK_RUNNING;
- remove_wait_queue(&ts->read_wait, &wait);
-
- return ptr == buffer ? err : ptr - buffer;
- }
- static unsigned int ucb1x00_ts_poll(struct file *filp, poll_table *wait)
- {
- struct ucb1x00_ts *ts = filp->private_data;
- int ret = 0;
- poll_wait(filp, &ts->read_wait, wait);
- if (ucb1x00_ts_evt_pending(ts))
- ret = POLLIN | POLLRDNORM;
- return ret;
- }
- static int ucb1x00_ts_fasync(int fd, struct file *filp, int on)
- {
- struct ucb1x00_ts *ts = filp->private_data;
- return fasync_helper(fd, filp, on, &ts->fasync);
- }
- static int ucb1x00_ts_open(struct inode *inode, struct file *filp)
- {
- struct ucb1x00_ts *ts = &ucbts;
- int ret = 0;
- ret = ucb1x00_ts_startup(ts);
- if (ret == 0)
- filp->private_data = ts;
- return ret;
- }
- /*
- * Release touchscreen resources. Disable IRQs.
- */
- static int ucb1x00_ts_release(struct inode *inode, struct file *filp)
- {
- struct ucb1x00_ts *ts = filp->private_data;
- down(&ts->sem);
- ucb1x00_ts_fasync(-1, filp, 0);
- ucb1x00_ts_shutdown(ts);
- up(&ts->sem);
- return 0;
- }
- static struct file_operations ucb1x00_fops = {
- owner: THIS_MODULE,
- read: ucb1x00_ts_read,
- poll: ucb1x00_ts_poll,
- open: ucb1x00_ts_open,
- release: ucb1x00_ts_release,
- fasync: ucb1x00_ts_fasync,
- };
- /*
- * The official UCB1x00 touchscreen is a miscdevice:
- * 10 char Non-serial mice, misc features
- * 14 = /dev/touchscreen/ucb1x00 UCB 1x00 touchscreen
- */
- static struct miscdevice ucb1x00_ts_dev = {
- minor: 14,
- name: "touchscreen/ucb1x00",
- fops: &ucb1x00_fops,
- };
- static inline int ucb1x00_ts_register(struct ucb1x00_ts *ts)
- {
- init_waitqueue_head(&ts->read_wait);
- return misc_register(&ucb1x00_ts_dev);
- }
- static inline void ucb1x00_ts_deregister(struct ucb1x00_ts *ts)
- {
- misc_deregister(&ucb1x00_ts_dev);
- }
- #else
- #define ucb1x00_ts_evt_clear(ts) do { } while (0)
- 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);
- }
- static inline void ucb1x00_ts_event_release(struct ucb1x00_ts *ts)
- {
- input_report_abs(&ts->idev, ABS_PRESSURE, 0);
- }
- static int ucb1x00_ts_open(struct input_dev *idev)
- {
- struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
- return ucb1x00_ts_startup(ts);
- }
- static void ucb1x00_ts_close(struct input_dev *idev)
- {
- struct ucb1x00_ts *ts = (struct ucb1x00_ts *)idev;
- down(&ts->sem);
- ucb1x00_ts_shutdown(ts);
- up(&ts->sem);
- }
- static inline int ucb1x00_ts_register(struct ucb1x00_ts *ts)
- {
- ts->idev.name = "Touchscreen panel";
- ts->idev.idproduct = 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);
- return 0;
- }
- static inline void ucb1x00_ts_deregister(struct ucb1x00_ts *ts)
- {
- input_unregister_device(&ts->idev);
- }
- #endif
- /*
- * Switch to interrupt mode.
- */
- static inline void ucb1x00_ts_mode_int(struct ucb1x00_ts *ts)
- {
- if (ts->ucb->id == UCB_ID_1400_BUGGY)
- ucb1x00_reg_write(ts->ucb, UCB_TS_CR,
- UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
- UCB_TS_CR_MODE_INT);
- 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_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). The UCB1400 access
- * functions are expected to be able to sleep as well.
- */
- 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();
- reparent_to_init();
- strcpy(tsk->comm, "ktsd");
- tsk->tty = NULL;
- /*
- * 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;
- /* only want to receive SIGKILL */
- spin_lock_irq(&tsk->sigmask_lock);
- siginitsetinv(&tsk->blocked, sigmask(SIGKILL));
- recalc_sigpending(tsk);
- spin_unlock_irq(&tsk->sigmask_lock);
- 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;
- }
- schedule_timeout(timeout);
- if (signal_pending(tsk))
- break;
- }
- remove_wait_queue(&ts->irq_wait, &wait);
- ts->rtask = NULL;
- ucb1x00_ts_evt_clear(ts);
- 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_startup(struct ucb1x00_ts *ts)
- {
- 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, 0);
- 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_shutdown(struct ucb1x00_ts *ts)
- {
- 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);
- }
- }
- #ifdef CONFIG_PM
- static int ucb1x00_ts_pm (struct pm_dev *dev, pm_request_t rqst, void *data)
- {
- struct ucb1x00_ts *ts = (struct ucb1x00_ts *) (dev->data);
- if (rqst == PM_RESUME && 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;
- }
- #endif
- /*
- * Initialisation.
- */
- static int __init ucb1x00_ts_init(void)
- {
- struct ucb1x00_ts *ts = &ucbts;
- ts->ucb = ucb1x00_get();
- if (!ts->ucb)
- return -ENODEV;
- ts->adcsync = adcsync;
- init_MUTEX(&ts->sem);
- #ifdef CONFIG_PM
- ts->pmdev = pm_register(PM_SYS_DEV, PM_SYS_UNKNOWN, ucb1x00_ts_pm);
- if (ts->pmdev == NULL)
- printk("ucb1x00_ts: unable to register in PM.n");
- else
- ts->pmdev->data = ts;
- #endif
- return ucb1x00_ts_register(ts);
- }
- static void __exit ucb1x00_ts_exit(void)
- {
- struct ucb1x00_ts *ts = &ucbts;
- ucb1x00_ts_deregister(ts);
- #ifdef CONFIG_PM
- if (ts->pmdev)
- pm_unregister(ts->pmdev);
- #endif
- }
- #ifndef MODULE
- /*
- * Parse kernel command-line options.
- *
- * syntax : ucbts=[sync|nosync],...
- */
- static int __init ucb1x00_ts_setup(char *str)
- {
- char *p;
- while ((p = strsep(&str, ",")) != NULL) {
- if (strcmp(p, "sync") == 0)
- adcsync = UCB_SYNC;
- }
- return 1;
- }
- __setup("ucbts=", ucb1x00_ts_setup);
- #else
- MODULE_PARM(adcsync, "i");
- MODULE_PARM_DESC(adcsync, "Enable use of ADCSYNC signal");
- #endif
- 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");