[net-next-2.6.git] / drivers / input / touchscreen / ucb1400_ts.c

/*
 *  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/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 <linux/freezer.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 {
	struct snd_ac97		*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 = input_get_drvdata(idev);
	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 = input_get_drvdata(idev);

	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);

	input_set_drvdata(idev, ucb);

	idev->dev.parent	= 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");
Commit	Line	Data
f40219bf NP	1	/*
	2	* Philips UCB1400 touchscreen driver
	3	*
	4	* Author: Nicolas Pitre
	5	* Created: September 25, 2006
	6	* Copyright: MontaVista Software, Inc.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* This code is heavily based on ucb1x00-*.c copyrighted by Russell King
	13	* covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
	14	* been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
	15	*/
	16
	17	#include <linux/module.h>
	18	#include <linux/moduleparam.h>
	19	#include <linux/init.h>
f40219bf NP	20	#include <linux/completion.h>
	21	#include <linux/delay.h>
	22	#include <linux/input.h>
	23	#include <linux/device.h>
	24	#include <linux/interrupt.h>
	25	#include <linux/suspend.h>
	26	#include <linux/slab.h>
	27	#include <linux/kthread.h>
bff19b1d	28	#include <linux/freezer.h>
f40219bf NP	29
	30	#include <sound/driver.h>
	31	#include <sound/core.h>
	32	#include <sound/ac97_codec.h>
	33
	34
	35	/*
	36	* Interesting UCB1400 AC-link registers
	37	*/
	38
	39	#define UCB_IE_RIS 0x5e
	40	#define UCB_IE_FAL 0x60
	41	#define UCB_IE_STATUS 0x62
	42	#define UCB_IE_CLEAR 0x62
	43	#define UCB_IE_ADC (1 << 11)
	44	#define UCB_IE_TSPX (1 << 12)
	45
	46	#define UCB_TS_CR 0x64
	47	#define UCB_TS_CR_TSMX_POW (1 << 0)
	48	#define UCB_TS_CR_TSPX_POW (1 << 1)
	49	#define UCB_TS_CR_TSMY_POW (1 << 2)
	50	#define UCB_TS_CR_TSPY_POW (1 << 3)
	51	#define UCB_TS_CR_TSMX_GND (1 << 4)
	52	#define UCB_TS_CR_TSPX_GND (1 << 5)
	53	#define UCB_TS_CR_TSMY_GND (1 << 6)
	54	#define UCB_TS_CR_TSPY_GND (1 << 7)
	55	#define UCB_TS_CR_MODE_INT (0 << 8)
	56	#define UCB_TS_CR_MODE_PRES (1 << 8)
	57	#define UCB_TS_CR_MODE_POS (2 << 8)
	58	#define UCB_TS_CR_BIAS_ENA (1 << 11)
	59	#define UCB_TS_CR_TSPX_LOW (1 << 12)
	60	#define UCB_TS_CR_TSMX_LOW (1 << 13)
	61
	62	#define UCB_ADC_CR 0x66
	63	#define UCB_ADC_SYNC_ENA (1 << 0)
	64	#define UCB_ADC_VREFBYP_CON (1 << 1)
	65	#define UCB_ADC_INP_TSPX (0 << 2)
	66	#define UCB_ADC_INP_TSMX (1 << 2)
	67	#define UCB_ADC_INP_TSPY (2 << 2)
	68	#define UCB_ADC_INP_TSMY (3 << 2)
	69	#define UCB_ADC_INP_AD0 (4 << 2)
	70	#define UCB_ADC_INP_AD1 (5 << 2)
	71	#define UCB_ADC_INP_AD2 (6 << 2)
	72	#define UCB_ADC_INP_AD3 (7 << 2)
	73	#define UCB_ADC_EXT_REF (1 << 5)
	74	#define UCB_ADC_START (1 << 7)
	75	#define UCB_ADC_ENA (1 << 15)
	76
	77	#define UCB_ADC_DATA 0x68
	78	#define UCB_ADC_DAT_VALID (1 << 15)
	79	#define UCB_ADC_DAT_VALUE(x) ((x) & 0x3ff)
	80
	81	#define UCB_ID 0x7e
	82	#define UCB_ID_1400 0x4304
	83
	84
	85	struct ucb1400 {
ca377fec	86	struct snd_ac97 *ac97;
f40219bf NP	87	struct input_dev *ts_idev;
	88
	89	int irq;
	90
	91	wait_queue_head_t ts_wait;
	92	struct task_struct *ts_task;
	93
	94	unsigned int irq_pending; /* not bit field shared */
	95	unsigned int ts_restart:1;
	96	unsigned int adcsync:1;
	97	};
	98
	99	static int adcsync;
	100
	101	static inline u16 ucb1400_reg_read(struct ucb1400 *ucb, u16 reg)
	102	{
	103	return ucb->ac97->bus->ops->read(ucb->ac97, reg);
	104	}
	105
	106	static inline void ucb1400_reg_write(struct ucb1400 *ucb, u16 reg, u16 val)
	107	{
	108	ucb->ac97->bus->ops->write(ucb->ac97, reg, val);
	109	}
	110
	111	static inline void ucb1400_adc_enable(struct ucb1400 *ucb)
	112	{
	113	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
	114	}
	115
	116	static unsigned int ucb1400_adc_read(struct ucb1400 *ucb, u16 adc_channel)
	117	{
	118	unsigned int val;
	119
	120	if (ucb->adcsync)
	121	adc_channel \|= UCB_ADC_SYNC_ENA;
	122
	123	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA \| adc_channel);
	124	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA \| adc_channel \| UCB_ADC_START);
	125
	126	for (;;) {
	127	val = ucb1400_reg_read(ucb, UCB_ADC_DATA);
	128	if (val & UCB_ADC_DAT_VALID)
	129	break;
	130	/* yield to other processes */
	131	set_current_state(TASK_INTERRUPTIBLE);
	132	schedule_timeout(1);
	133	}
	134
	135	return UCB_ADC_DAT_VALUE(val);
	136	}
	137
	138	static inline void ucb1400_adc_disable(struct ucb1400 *ucb)
	139	{
	140	ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
	141	}
	142
	143	/* Switch to interrupt mode. */
	144	static inline void ucb1400_ts_mode_int(struct ucb1400 *ucb)
	145	{
	146	ucb1400_reg_write(ucb, UCB_TS_CR,
	147	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
	148	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
	149	UCB_TS_CR_MODE_INT);
	150	}
151
152	/*
153	* Switch to pressure mode, and read pressure. We don't need to wait
154	* here, since both plates are being driven.
155	*/
156	static inline unsigned int ucb1400_ts_read_pressure(struct ucb1400 *ucb)
157	{
158	ucb1400_reg_write(ucb, UCB_TS_CR,
159	UCB_TS_CR_TSMX_POW \| UCB_TS_CR_TSPX_POW \|
160	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_GND \|
161	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
162	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
163	}
164
165	/*
166	* Switch to X position mode and measure Y plate. We switch the plate
167	* configuration in pressure mode, then switch to position mode. This
168	* gives a faster response time. Even so, we need to wait about 55us
169	* for things to stabilise.
170	*/
171	static inline unsigned int ucb1400_ts_read_xpos(struct ucb1400 *ucb)
172	{
173	ucb1400_reg_write(ucb, UCB_TS_CR,
174	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
175	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
176	ucb1400_reg_write(ucb, UCB_TS_CR,
177	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
178	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
179	ucb1400_reg_write(ucb, UCB_TS_CR,
180	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
181	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
182
183	udelay(55);
184
185	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPY);
186	}
187
188	/*
189	* Switch to Y position mode and measure X plate. We switch the plate
190	* configuration in pressure mode, then switch to position mode. This
191	* gives a faster response time. Even so, we need to wait about 55us
192	* for things to stabilise.
193	*/
194	static inline unsigned int ucb1400_ts_read_ypos(struct ucb1400 *ucb)
195	{
196	ucb1400_reg_write(ucb, UCB_TS_CR,
197	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
198	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
199	ucb1400_reg_write(ucb, UCB_TS_CR,
200	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
201	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
202	ucb1400_reg_write(ucb, UCB_TS_CR,
203	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
204	UCB_TS_CR_MODE_POS \| UCB_TS_CR_BIAS_ENA);
205
206	udelay(55);
207
208	return ucb1400_adc_read(ucb, UCB_ADC_INP_TSPX);
209	}
210
211	/*
212	* Switch to X plate resistance mode. Set MX to ground, PX to
213	* supply. Measure current.
214	*/
215	static inline unsigned int ucb1400_ts_read_xres(struct ucb1400 *ucb)
216	{
217	ucb1400_reg_write(ucb, UCB_TS_CR,
218	UCB_TS_CR_TSMX_GND \| UCB_TS_CR_TSPX_POW \|
219	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
220	return ucb1400_adc_read(ucb, 0);
221	}
222
223	/*
224	* Switch to Y plate resistance mode. Set MY to ground, PY to
225	* supply. Measure current.
226	*/
227	static inline unsigned int ucb1400_ts_read_yres(struct ucb1400 *ucb)
228	{
229	ucb1400_reg_write(ucb, UCB_TS_CR,
230	UCB_TS_CR_TSMY_GND \| UCB_TS_CR_TSPY_POW \|
231	UCB_TS_CR_MODE_PRES \| UCB_TS_CR_BIAS_ENA);
232	return ucb1400_adc_read(ucb, 0);
233	}
234
235	static inline int ucb1400_ts_pen_down(struct ucb1400 *ucb)
236	{
237	unsigned short val = ucb1400_reg_read(ucb, UCB_TS_CR);
238	return (val & (UCB_TS_CR_TSPX_LOW \| UCB_TS_CR_TSMX_LOW));
239	}
240
241	static inline void ucb1400_ts_irq_enable(struct ucb1400 *ucb)
242	{
243	ucb1400_reg_write(ucb, UCB_IE_CLEAR, UCB_IE_TSPX);
244	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
245	ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_TSPX);
246	}
247
248	static inline void ucb1400_ts_irq_disable(struct ucb1400 *ucb)
249	{
250	ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
251	}
252
253	static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)
254	{
255	input_report_abs(idev, ABS_X, x);
256	input_report_abs(idev, ABS_Y, y);
257	input_report_abs(idev, ABS_PRESSURE, pressure);
258	input_sync(idev);
259	}
260
261	static void ucb1400_ts_event_release(struct input_dev *idev)
262	{
263	input_report_abs(idev, ABS_PRESSURE, 0);
264	input_sync(idev);
265	}
266
267	static void ucb1400_handle_pending_irq(struct ucb1400 *ucb)
268	{
269	unsigned int isr;
270
271	isr = ucb1400_reg_read(ucb, UCB_IE_STATUS);
272	ucb1400_reg_write(ucb, UCB_IE_CLEAR, isr);
273	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
274
275	if (isr & UCB_IE_TSPX)
276	ucb1400_ts_irq_disable(ucb);
277	else
278	printk(KERN_ERR "ucb1400: unexpected IE_STATUS = %#x\n", isr);
279
280	enable_irq(ucb->irq);
281	}
282
283	static int ucb1400_ts_thread(void *_ucb)
284	{
285	struct ucb1400 *ucb = _ucb;
286	struct task_struct *tsk = current;
287	int valid = 0;
288
289	tsk->policy = SCHED_FIFO;
290	tsk->rt_priority = 1;
291
292	while (!kthread_should_stop()) {
293	unsigned int x, y, p;
294	long timeout;
295
296	ucb->ts_restart = 0;
297
298	if (ucb->irq_pending) {
299	ucb->irq_pending = 0;
300	ucb1400_handle_pending_irq(ucb);
301	}
302
303	ucb1400_adc_enable(ucb);
304	x = ucb1400_ts_read_xpos(ucb);
305	y = ucb1400_ts_read_ypos(ucb);
306	p = ucb1400_ts_read_pressure(ucb);
307	ucb1400_adc_disable(ucb);
308
309	/* Switch back to interrupt mode. */
310	ucb1400_ts_mode_int(ucb);
311
312	msleep(10);
313
314	if (ucb1400_ts_pen_down(ucb)) {
315	ucb1400_ts_irq_enable(ucb);
316
317	/*
318	* If we spat out a valid sample set last time,
319	* spit out a "pen off" sample here.
320	*/
321	if (valid) {
322	ucb1400_ts_event_release(ucb->ts_idev);
323	valid = 0;
324	}
325
326	timeout = MAX_SCHEDULE_TIMEOUT;
327	} else {
328	valid = 1;
329	ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);
330	timeout = msecs_to_jiffies(10);
331	}
332
333	wait_event_interruptible_timeout(ucb->ts_wait,
334	ucb->irq_pending \|\| ucb->ts_restart \|\| kthread_should_stop(),
335	timeout);
336	try_to_freeze();
337	}
338
339	/* Send the "pen off" if we are stopping with the pen still active */
340	if (valid)
341	ucb1400_ts_event_release(ucb->ts_idev);
342
343	ucb->ts_task = NULL;
344	return 0;
345	}
346
347	/*
348	* A restriction with interrupts exists when using the ucb1400, as
349	* the codec read/write routines may sleep while waiting for codec
350	* access completion and uses semaphores for access control to the
351	* AC97 bus. A complete codec read cycle could take anywhere from
352	* 60 to 100uSec so we definitely don't want to spin inside the
353	* interrupt handler waiting for codec access. So, we handle the
354	* interrupt by scheduling a RT kernel thread to run in process
355	* context instead of interrupt context.
356	*/
357	static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)
358	{
359	struct ucb1400 *ucb = devid;
360
361	if (irqnr == ucb->irq) {
362	disable_irq(ucb->irq);
363	ucb->irq_pending = 1;
364	wake_up(&ucb->ts_wait);
365	return IRQ_HANDLED;
366	}
367	return IRQ_NONE;
368	}
369
370	static int ucb1400_ts_open(struct input_dev *idev)
371	{
40b9b0b8	372	struct ucb1400 *ucb = input_get_drvdata(idev);
f40219bf NP	373	int ret = 0;
	374
	375	BUG_ON(ucb->ts_task);
	376
	377	ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");
	378	if (IS_ERR(ucb->ts_task)) {
	379	ret = PTR_ERR(ucb->ts_task);
	380	ucb->ts_task = NULL;
	381	}
	382
	383	return ret;
	384	}
	385
	386	static void ucb1400_ts_close(struct input_dev *idev)
	387	{
40b9b0b8	388	struct ucb1400 *ucb = input_get_drvdata(idev);
f40219bf NP	389
	390	if (ucb->ts_task)
	391	kthread_stop(ucb->ts_task);
	392
	393	ucb1400_ts_irq_disable(ucb);
	394	ucb1400_reg_write(ucb, UCB_TS_CR, 0);
	395	}
	396
	397	#ifdef CONFIG_PM
	398	static int ucb1400_ts_resume(struct device *dev)
	399	{
	400	struct ucb1400 *ucb = dev_get_drvdata(dev);
	401
	402	if (ucb->ts_task) {
	403	/*
	404	* Restart the TS thread to ensure the
	405	* TS interrupt mode is set up again
	406	* after sleep.
	407	*/
	408	ucb->ts_restart = 1;
	409	wake_up(&ucb->ts_wait);
	410	}
	411	return 0;
	412	}
	413	#else
	414	#define ucb1400_ts_resume NULL
	415	#endif
	416
	417	#ifndef NO_IRQ
	418	#define NO_IRQ 0
	419	#endif
	420
	421	/*
	422	* Try to probe our interrupt, rather than relying on lots of
	423	* hard-coded machine dependencies.
	424	*/
	425	static int ucb1400_detect_irq(struct ucb1400 *ucb)
	426	{
	427	unsigned long mask, timeout;
	428
	429	mask = probe_irq_on();
	430	if (!mask) {
	431	probe_irq_off(mask);
	432	return -EBUSY;
	433	}
	434
	435	/* Enable the ADC interrupt. */
	436	ucb1400_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
	437	ucb1400_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
	438	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
	439	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
	440
	441	/* Cause an ADC interrupt. */
	442	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
	443	ucb1400_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA \| UCB_ADC_START);
	444
	445	/* Wait for the conversion to complete. */
	446	timeout = jiffies + HZ/2;
	447	while (!(ucb1400_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VALID)) {
	448	cpu_relax();
	449	if (time_after(jiffies, timeout)) {
	450	printk(KERN_ERR "ucb1400: timed out in IRQ probe\n");
	451	probe_irq_off(mask);
	452	return -ENODEV;
453	}
454	}
455	ucb1400_reg_write(ucb, UCB_ADC_CR, 0);
456
457	/* Disable and clear interrupt. */
458	ucb1400_reg_write(ucb, UCB_IE_RIS, 0);
459	ucb1400_reg_write(ucb, UCB_IE_FAL, 0);
460	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
461	ucb1400_reg_write(ucb, UCB_IE_CLEAR, 0);
462
463	/* Read triggered interrupt. */
464	ucb->irq = probe_irq_off(mask);
465	if (ucb->irq < 0 \|\| ucb->irq == NO_IRQ)
466	return -ENODEV;
467
468	return 0;
469	}
470
471	static int ucb1400_ts_probe(struct device *dev)
472	{
473	struct ucb1400 *ucb;
474	struct input_dev *idev;
475	int error, id, x_res, y_res;
476
477	ucb = kzalloc(sizeof(struct ucb1400), GFP_KERNEL);
478	idev = input_allocate_device();
479	if (!ucb \|\| !idev) {
480	error = -ENOMEM;
481	goto err_free_devs;
482	}
483
484	ucb->ts_idev = idev;
485	ucb->adcsync = adcsync;
486	ucb->ac97 = to_ac97_t(dev);
487	init_waitqueue_head(&ucb->ts_wait);
488
489	id = ucb1400_reg_read(ucb, UCB_ID);
490	if (id != UCB_ID_1400) {
491	error = -ENODEV;
492	goto err_free_devs;
493	}
494
495	error = ucb1400_detect_irq(ucb);
496	if (error) {
497	printk(KERN_ERR "UCB1400: IRQ probe failed\n");
498	goto err_free_devs;
499	}
500
501	error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,
502	"UCB1400", ucb);
503	if (error) {
504	printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",
505	ucb->irq, error);
506	goto err_free_devs;
507	}
508	printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);
509
40b9b0b8 DT	510	input_set_drvdata(idev, ucb);
40b9b0b8 DT	511
a5394fb0	512	idev->dev.parent = dev;
f40219bf NP	513	idev->name = "UCB1400 touchscreen interface";
	514	idev->id.vendor = ucb1400_reg_read(ucb, AC97_VENDOR_ID1);
	515	idev->id.product = id;
	516	idev->open = ucb1400_ts_open;
	517	idev->close = ucb1400_ts_close;
	518	idev->evbit[0] = BIT(EV_ABS);
	519
	520	ucb1400_adc_enable(ucb);
	521	x_res = ucb1400_ts_read_xres(ucb);
	522	y_res = ucb1400_ts_read_yres(ucb);
	523	ucb1400_adc_disable(ucb);
	524	printk(KERN_DEBUG "UCB1400: x/y = %d/%d\n", x_res, y_res);
	525
	526	input_set_abs_params(idev, ABS_X, 0, x_res, 0, 0);
	527	input_set_abs_params(idev, ABS_Y, 0, y_res, 0, 0);
	528	input_set_abs_params(idev, ABS_PRESSURE, 0, 0, 0, 0);
	529
	530	error = input_register_device(idev);
	531	if (error)
	532	goto err_free_irq;
	533
	534	dev_set_drvdata(dev, ucb);
	535	return 0;
	536
	537	err_free_irq:
	538	free_irq(ucb->irq, ucb);
	539	err_free_devs:
	540	input_free_device(idev);
	541	kfree(ucb);
	542	return error;
	543	}
	544
	545	static int ucb1400_ts_remove(struct device *dev)
	546	{
	547	struct ucb1400 *ucb = dev_get_drvdata(dev);
	548
	549	free_irq(ucb->irq, ucb);
	550	input_unregister_device(ucb->ts_idev);
	551	dev_set_drvdata(dev, NULL);
	552	kfree(ucb);
	553	return 0;
	554	}
	555
	556	static struct device_driver ucb1400_ts_driver = {
	557	.owner = THIS_MODULE,
	558	.bus = &ac97_bus_type,
	559	.probe = ucb1400_ts_probe,
	560	.remove = ucb1400_ts_remove,
	561	.resume = ucb1400_ts_resume,
	562	};
	563
	564	static int __init ucb1400_ts_init(void)
	565	{
	566	return driver_register(&ucb1400_ts_driver);
	567	}
	568
	569	static void __exit ucb1400_ts_exit(void)
	570	{
	571	driver_unregister(&ucb1400_ts_driver);
	572	}
	573
	574	module_param(adcsync, int, 0444);
	575
	576	module_init(ucb1400_ts_init);
577	module_exit(ucb1400_ts_exit);
578
579	MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
580	MODULE_LICENSE("GPL");