--- /dev/null
+/*
+ * Philips UCB1400 touchscreen driver
+ *
+ * Author: Nicolas Pitre
+ * Created: September 25, 2006
+ * Copyright: MontaVista Software, Inc.
+ *
+ * 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.
+ *
+ * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
+ * covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
+ * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/ac97_codec.h>
+
+
+/*
+ * Interesting UCB1400 AC-link registers
+ */
+
+#define UCB_IE_RIS 0x5e
+#define UCB_IE_FAL 0x60
+#define UCB_IE_STATUS 0x62
+#define UCB_IE_CLEAR 0x62
+#define UCB_IE_ADC (1 << 11)
+#define UCB_IE_TSPX (1 << 12)
+
+#define UCB_TS_CR 0x64
+#define UCB_TS_CR_TSMX_POW (1 << 0)
+#define UCB_TS_CR_TSPX_POW (1 << 1)
+#define UCB_TS_CR_TSMY_POW (1 << 2)
+#define UCB_TS_CR_TSPY_POW (1 << 3)
+#define UCB_TS_CR_TSMX_GND (1 << 4)
+#define UCB_TS_CR_TSPX_GND (1 << 5)
+#define UCB_TS_CR_TSMY_GND (1 << 6)
+#define UCB_TS_CR_TSPY_GND (1 << 7)
+#define UCB_TS_CR_MODE_INT (0 << 8)
+#define UCB_TS_CR_MODE_PRES (1 << 8)
+#define UCB_TS_CR_MODE_POS (2 << 8)
+#define UCB_TS_CR_BIAS_ENA (1 << 11)
+#define UCB_TS_CR_TSPX_LOW (1 << 12)
+#define UCB_TS_CR_TSMX_LOW (1 << 13)
+
+#define UCB_ADC_CR 0x66
+#define UCB_ADC_SYNC_ENA (1 << 0)
+#define UCB_ADC_VREFBYP_CON (1 << 1)
+#define UCB_ADC_INP_TSPX (0 << 2)
+#define UCB_ADC_INP_TSMX (1 << 2)
+#define UCB_ADC_INP_TSPY (2 << 2)
+#define UCB_ADC_INP_TSMY (3 << 2)
+#define UCB_ADC_INP_AD0 (4 << 2)
+#define UCB_ADC_INP_AD1 (5 << 2)
+#define UCB_ADC_INP_AD2 (6 << 2)
+#define UCB_ADC_INP_AD3 (7 << 2)
+#define UCB_ADC_EXT_REF (1 << 5)
+#define UCB_ADC_START (1 << 7)
+#define UCB_ADC_ENA (1 << 15)
+
+#define UCB_ADC_DATA 0x68
+#define UCB_ADC_DAT_VALID (1 << 15)
+#define UCB_ADC_DAT_VALUE(x) ((x) & 0x3ff)
+
+#define UCB_ID 0x7e
+#define UCB_ID_1400 0x4304
+
+
+struct ucb1400 {
+ ac97_t *ac97;
+ struct input_dev *ts_idev;
+
+ int irq;
+
+ wait_queue_head_t ts_wait;
+ struct task_struct *ts_task;
+
+ unsigned int irq_pending; /* not bit field shared */
+ unsigned int ts_restart:1;
+ unsigned int adcsync:1;
+};
+
+static int adcsync;
+
+static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
+{
+ return ucb->ac97->bus->ops->read(ucb->ac97, reg);
+}
+
+static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
+{
+ ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
+}
+
+static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
+}
+
+static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
+{
+ unsigned int val;
+
+ if (ucb->adcsync)
+ adc_channel |= UCB_ADC_SYNC_ENA;
+
+ ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel);
+ ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | adc_channel | UCB_ADC_START);
+
+ for (;;) {
+ val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
+ if (val & UCB_ADC_DAT_VALID)
+ break;
+ /* yield to other processes */
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(1);
+ }
+
+ return UCB_ADC_DAT_VALUE(val);
+}
+
+static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
+}
+
+/* Switch to interrupt mode. */
+static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(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 ucb1400_ts_read_pressure(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(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 ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
+}
+
+/*
+ * 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 ucb1400_ts_read_xpos(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_TS_CR,
+ UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+ UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+ ucb1400_reg_write(ucb, UCB_TS_CR,
+ UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
+ UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+ ucb1400_reg_write(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 ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
+}
+
+/*
+ * 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 ucb1400_ts_read_ypos(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_TS_CR,
+ UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+ UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+ ucb1400_reg_write(ucb, UCB_TS_CR,
+ UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
+ UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
+ ucb1400_reg_write(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 ucb1400_adc_read(ucb, UCB_ADC_INP_TSPX);
+}
+
+/*
+ * Switch to X plate resistance mode. Set MX to ground, PX to
+ * supply. Measure current.
+ */
+static inline unsigned int ucb1400_ts_read_xres(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(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 ucb1400_adc_read(ucb, 0);
+}
+
+/*
+ * Switch to Y plate resistance mode. Set MY to ground, PY to
+ * supply. Measure current.
+ */
+static inline unsigned int ucb1400_ts_read_yres(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(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 ucb1400_adc_read(ucb, 0);
+}
+
+static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
+{
+ unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
+ return (val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW));
+}
+
+static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+ ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
+}
+
+static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
+{
+ ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
+}
+
+static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
+{
+ input_report_abs(idev, ABS_X, x);
+ input_report_abs(idev, ABS_Y, y);
+ input_report_abs(idev, ABS_PRESSURE, pressure);
+ input_sync(idev);
+}
+
+static void ucb1400_ts_event_release(struct input_dev *idev)
+{
+ input_report_abs(idev, ABS_PRESSURE, 0);
+ input_sync(idev);
+}
+
+static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
+{
+ unsigned int isr;
+
+ isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+ if (isr & UCB_IE_TSPX)
+ ucb1400_ts_irq_disable(ucb);
+ else
+ printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
+
+ enable_irq(ucb->irq);
+}
+
+static int ucb1400_ts_thread(void *_ucb)
+{
+ struct ucb1400 *ucb = _ucb;
+ struct task_struct *tsk = current;
+ int valid = 0;
+
+ tsk->policy = SCHED_FIFO;
+ tsk->rt_priority = 1;
+
+ while (!kthread_should_stop()) {
+ unsigned int x, y, p;
+ long timeout;
+
+ ucb->ts_restart = 0;
+
+ if (ucb->irq_pending) {
+ ucb->irq_pending = 0;
+ ucb1400_handle_pending_irq(ucb);
+ }
+
+ ucb1400_adc_enable(ucb);
+ x = ucb1400_ts_read_xpos(ucb);
+ y = ucb1400_ts_read_ypos(ucb);
+ p = ucb1400_ts_read_pressure(ucb);
+ ucb1400_adc_disable(ucb);
+
+ /* Switch back to interrupt mode. */
+ ucb1400_ts_mode_int(ucb);
+
+ msleep(10);
+
+ if (ucb1400_ts_pen_down(ucb)) {
+ ucb1400_ts_irq_enable(ucb);
+
+ /*
+ * If we spat out a valid sample set last time,
+ * spit out a "pen off" sample here.
+ */
+ if (valid) {
+ ucb1400_ts_event_release(ucb->ts_idev);
+ valid = 0;
+ }
+
+ timeout = MAX_SCHEDULE_TIMEOUT;
+ } else {
+ valid = 1;
+ ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
+ timeout = msecs_to_jiffies(10);
+ }
+
+ wait_event_interruptible_timeout(ucb->ts_wait,
+ ucb->irq_pending || ucb->ts_restart || kthread_should_stop(),
+ timeout);
+ try_to_freeze();
+ }
+
+ /* Send the "pen off" if we are stopping with the pen still active */
+ if (valid)
+ ucb1400_ts_event_release(ucb->ts_idev);
+
+ ucb->ts_task = NULL;
+ return 0;
+}
+
+/*
+ * A restriction with interrupts exists when using the ucb1400, as
+ * the codec read/write routines may sleep while waiting for codec
+ * access completion and uses semaphores for access control to the
+ * AC97 bus. A complete codec read cycle could take anywhere from
+ * 60 to 100uSec so we *definitely* don't want to spin inside the
+ * interrupt handler waiting for codec access. So, we handle the
+ * interrupt by scheduling a RT kernel thread to run in process
+ * context instead of interrupt context.
+ */
+static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
+{
+ struct ucb1400 *ucb = devid;
+
+ if (irqnr == ucb->irq) {
+ disable_irq(ucb->irq);
+ ucb->irq_pending = 1;
+ wake_up(&ucb->ts_wait);
+ return IRQ_HANDLED;
+ }
+ return IRQ_NONE;
+}
+
+static int ucb1400_ts_open(struct input_dev *idev)
+{
+ struct ucb1400 *ucb = idev->private;
+ int ret = 0;
+
+ BUG_ON(ucb->ts_task);
+
+ ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
+ if (IS_ERR(ucb->ts_task)) {
+ ret = PTR_ERR(ucb->ts_task);
+ ucb->ts_task = NULL;
+ }
+
+ return ret;
+}
+
+static void ucb1400_ts_close(struct input_dev *idev)
+{
+ struct ucb1400 *ucb = idev->private;
+
+ if (ucb->ts_task)
+ kthread_stop(ucb->ts_task);
+
+ ucb1400_ts_irq_disable(ucb);
+ ucb1400_reg_write(ucb, UCB_TS_CR, 0);
+}
+
+#ifdef CONFIG_PM
+static int ucb1400_ts_resume(struct device *dev)
+{
+ struct ucb1400 *ucb = dev_get_drvdata(dev);
+
+ if (ucb->ts_task) {
+ /*
+ * Restart the TS thread to ensure the
+ * TS interrupt mode is set up again
+ * after sleep.
+ */
+ ucb->ts_restart = 1;
+ wake_up(&ucb->ts_wait);
+ }
+ return 0;
+}
+#else
+#define ucb1400_ts_resume NULL
+#endif
+
+#ifndef NO_IRQ
+#define NO_IRQ 0
+#endif
+
+/*
+ * Try to probe our interrupt, rather than relying on lots of
+ * hard-coded machine dependencies.
+ */
+static int ucb1400_detect_irq(struct ucb1400 *ucb)
+{
+ unsigned long mask, timeout;
+
+ mask = probe_irq_on();
+ if (!mask) {
+ probe_irq_off(mask);
+ return -EBUSY;
+ }
+
+ /* Enable the ADC interrupt. */
+ ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
+ ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+ /* Cause an ADC interrupt. */
+ ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
+ ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
+
+ /* Wait for the conversion to complete. */
+ timeout = jiffies + HZ/2;
+ while (!(ucb1400_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VALID)) {
+ cpu_relax();
+ if (time_after(jiffies, timeout)) {
+ printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
+ probe_irq_off(mask);
+ return -ENODEV;
+ }
+ }
+ ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
+
+ /* Disable and clear interrupt. */
+ ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
+ ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
+ ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
+
+ /* Read triggered interrupt. */
+ ucb->irq = probe_irq_off(mask);
+ if (ucb->irq < 0 || ucb->irq == NO_IRQ)
+ return -ENODEV;
+
+ return 0;
+}
+
+static int ucb1400_ts_probe(struct device *dev)
+{
+ struct ucb1400 *ucb;
+ struct input_dev *idev;
+ int error, id, x_res, y_res;
+
+ ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
+ idev = input_allocate_device();
+ if (!ucb || !idev) {
+ error = -ENOMEM;
+ goto err_free_devs;
+ }
+
+ ucb->ts_idev = idev;
+ ucb->adcsync = adcsync;
+ ucb->ac97 = to_ac97_t(dev);
+ init_waitqueue_head(&ucb->ts_wait);
+
+ id = ucb1400_reg_read(ucb, UCB_ID);
+ if (id != UCB_ID_1400) {
+ error = -ENODEV;
+ goto err_free_devs;
+ }
+
+ error = ucb1400_detect_irq(ucb);
+ if (error) {
+ printk(KERN_ERR "UCB1400: IRQ probe failed\n");
+ goto err_free_devs;
+ }
+
+ error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
+ "UCB1400", ucb);
+ if (error) {
+ printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
+ ucb->irq, error);
+ goto err_free_devs;
+ }
+ printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
+
+ idev->private = ucb;
+ idev->cdev.dev = dev;
+ idev->name = "UCB1400 touchscreen interface";
+ idev->id.vendor = ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
+ idev->id.product = id;
+ idev->open = ucb1400_ts_open;
+ idev->close = ucb1400_ts_close;
+ idev->evbit[0] = BIT(EV_ABS);
+
+ ucb1400_adc_enable(ucb);
+ x_res = ucb1400_ts_read_xres(ucb);
+ y_res = ucb1400_ts_read_yres(ucb);
+ ucb1400_adc_disable(ucb);
+ printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
+
+ input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
+ input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
+ input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
+
+ error = input_register_device(idev);
+ if (error)
+ goto err_free_irq;
+
+ dev_set_drvdata(dev, ucb);
+ return 0;
+
+ err_free_irq:
+ free_irq(ucb->irq, ucb);
+ err_free_devs:
+ input_free_device(idev);
+ kfree(ucb);
+ return error;
+}
+
+static int ucb1400_ts_remove(struct device *dev)
+{
+ struct ucb1400 *ucb = dev_get_drvdata(dev);
+
+ free_irq(ucb->irq, ucb);
+ input_unregister_device(ucb->ts_idev);
+ dev_set_drvdata(dev, NULL);
+ kfree(ucb);
+ return 0;
+}
+
+static struct device_driver ucb1400_ts_driver = {
+ .owner = THIS_MODULE,
+ .bus = &ac97_bus_type,
+ .probe = ucb1400_ts_probe,
+ .remove = ucb1400_ts_remove,
+ .resume = ucb1400_ts_resume,
+};
+
+static int __init ucb1400_ts_init(void)
+{
+ return driver_register(&ucb1400_ts_driver);
+}
+
+static void __exit ucb1400_ts_exit(void)
+{
+ driver_unregister(&ucb1400_ts_driver);
+}
+
+module_param(adcsync, int, 0444);
+
+module_init(ucb1400_ts_init);
+module_exit(ucb1400_ts_exit);
+
+MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
+MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / commitdiff