Input: add Philips UCB1400 touchscreen driver

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 579 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ucb1400_ts.c b/drivers/input/touchscreen/ucb1400_ts.c
new file mode 100644
index 000000000000..6ef08369f65b
--- /dev/null
+++ b/drivers/input/touchscreen/ucb1400_ts.c
@@ -0,0 +1,579 @@
+/*
+ *  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");