Input: add tsc2007 based touchscreen driver

This drive has been tested on ARM9 based SoC - MV86XX.

Signed-off-by: Kwangwoo Lee <kwangwoo.lee@gmail.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 381 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
new file mode 100644
index 000000000000..b75dc2990574
--- /dev/null
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -0,0 +1,381 @@
+/*
+ * drivers/input/touchscreen/tsc2007.c
+ *
+ * Copyright (c) 2008 MtekVision Co., Ltd.
+ *      Kwangwoo Lee <kwlee@mtekvision.com>
+ *
+ * Using code from:
+ *  - ads7846.c
+ *      Copyright (c) 2005 David Brownell
+ *      Copyright (c) 2006 Nokia Corporation
+ *  - corgi_ts.c
+ *      Copyright (C) 2004-2005 Richard Purdie
+ *  - omap_ts.[hc], ads7846.h, ts_osk.c
+ *      Copyright (C) 2002 MontaVista Software
+ *      Copyright (C) 2004 Texas Instruments
+ *      Copyright (C) 2005 Dirk Behme
+ *
+ *  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.
+ */
+
+#include <linux/module.h>
+#include <linux/hrtimer.h>
+#include <linux/slab.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/i2c/tsc2007.h>
+
+#define TS_POLL_DELAY   (10 * 1000)     /* ns delay before the first sample */
+#define TS_POLL_PERIOD  (5 * 1000)      /* ns delay between samples */
+
+#define TSC2007_MEASURE_TEMP0           (0x0 << 4)
+#define TSC2007_MEASURE_AUX             (0x2 << 4)
+#define TSC2007_MEASURE_TEMP1           (0x4 << 4)
+#define TSC2007_ACTIVATE_XN             (0x8 << 4)
+#define TSC2007_ACTIVATE_YN             (0x9 << 4)
+#define TSC2007_ACTIVATE_YP_XN          (0xa << 4)
+#define TSC2007_SETUP                   (0xb << 4)
+#define TSC2007_MEASURE_X               (0xc << 4)
+#define TSC2007_MEASURE_Y               (0xd << 4)
+#define TSC2007_MEASURE_Z1              (0xe << 4)
+#define TSC2007_MEASURE_Z2              (0xf << 4)
+
+#define TSC2007_POWER_OFF_IRQ_EN        (0x0 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS0         (0x1 << 2)
+#define TSC2007_ADC_OFF_IRQ_EN          (0x2 << 2)
+#define TSC2007_ADC_ON_IRQ_DIS1         (0x3 << 2)
+
+#define TSC2007_12BIT                   (0x0 << 1)
+#define TSC2007_8BIT                    (0x1 << 1)
+
+#define MAX_12BIT                       ((1 << 12) - 1)
+
+#define ADC_ON_12BIT    (TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
+
+#define READ_Y          (ADC_ON_12BIT | TSC2007_MEASURE_Y)
+#define READ_Z1         (ADC_ON_12BIT | TSC2007_MEASURE_Z1)
+#define READ_Z2         (ADC_ON_12BIT | TSC2007_MEASURE_Z2)
+#define READ_X          (ADC_ON_12BIT | TSC2007_MEASURE_X)
+#define PWRDOWN         (TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
+
+struct ts_event {
+        u16     x;
+        u16     y;
+        u16     z1, z2;
+};
+
+struct tsc2007 {
+        struct input_dev        *input;
+        char                    phys[32];
+        struct hrtimer          timer;
+        struct ts_event         tc;
+
+        struct i2c_client       *client;
+
+        spinlock_t              lock;
+
+        u16                     model;
+        u16                     x_plate_ohms;
+
+        unsigned                pendown;
+        int                     irq;
+
+        int                     (*get_pendown_state)(void);
+        void                    (*clear_penirq)(void);
+};
+
+static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
+{
+        s32 data;
+        u16 val;
+
+        data = i2c_smbus_read_word_data(tsc->client, cmd);
+        if (data < 0) {
+                dev_err(&tsc->client->dev, "i2c io error: %d\n", data);
+                return data;
+        }
+
+        /* The protocol and raw data format from i2c interface:
+         * S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P
+         * Where DataLow has [D11-D4], DataHigh has [D3-D0 << 4 | Dummy 4bit].
+         */
+        val = swab16(data) >> 4;
+
+        dev_dbg(&tsc->client->dev, "data: 0x%x, val: 0x%x\n", data, val);
+
+        return val;
+}
+
+static void tsc2007_send_event(void *tsc)
+{
+        struct tsc2007  *ts = tsc;
+        u32             rt;
+        u16             x, y, z1, z2;
+
+        x = ts->tc.x;
+        y = ts->tc.y;
+        z1 = ts->tc.z1;
+        z2 = ts->tc.z2;
+
+        /* range filtering */
+        if (x == MAX_12BIT)
+                x = 0;
+
+        if (likely(x && z1)) {
+                /* compute touch pressure resistance using equation #1 */
+                rt = z2;
+                rt -= z1;
+                rt *= x;
+                rt *= ts->x_plate_ohms;
+                rt /= z1;
+                rt = (rt + 2047) >> 12;
+        } else
+                rt = 0;
+
+        /* Sample found inconsistent by debouncing or pressure is beyond
+         * the maximum. Don't report it to user space, repeat at least
+         * once more the measurement
+         */
+        if (rt > MAX_12BIT) {
+                dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
+
+                hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+                              HRTIMER_MODE_REL);
+                return;
+        }
+
+        /* NOTE: We can't rely on the pressure to determine the pen down
+         * state, even this controller has a pressure sensor.  The pressure
+         * value can fluctuate for quite a while after lifting the pen and
+         * in some cases may not even settle at the expected value.
+         *
+         * The only safe way to check for the pen up condition is in the
+         * timer by reading the pen signal state (it's a GPIO _and_ IRQ).
+         */
+        if (rt) {
+                struct input_dev *input = ts->input;
+
+                if (!ts->pendown) {
+                        dev_dbg(&ts->client->dev, "DOWN\n");
+
+                        input_report_key(input, BTN_TOUCH, 1);
+                        ts->pendown = 1;
+                }
+
+                input_report_abs(input, ABS_X, x);
+                input_report_abs(input, ABS_Y, y);
+                input_report_abs(input, ABS_PRESSURE, rt);
+
+                input_sync(input);
+
+                dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
+                        x, y, rt);
+        }
+
+        hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+                        HRTIMER_MODE_REL);
+}
+
+static int tsc2007_read_values(struct tsc2007 *tsc)
+{
+        /* y- still on; turn on only y+ (and ADC) */
+        tsc->tc.y = tsc2007_xfer(tsc, READ_Y);
+
+        /* turn y- off, x+ on, then leave in lowpower */
+        tsc->tc.x = tsc2007_xfer(tsc, READ_X);
+
+        /* turn y+ off, x- on; we'll use formula #1 */
+        tsc->tc.z1 = tsc2007_xfer(tsc, READ_Z1);
+        tsc->tc.z2 = tsc2007_xfer(tsc, READ_Z2);
+
+        /* power down */
+        tsc2007_xfer(tsc, PWRDOWN);
+
+        return 0;
+}
+
+static enum hrtimer_restart tsc2007_timer(struct hrtimer *handle)
+{
+        struct tsc2007 *ts = container_of(handle, struct tsc2007, timer);
+
+        spin_lock_irq(&ts->lock);
+
+        if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
+                struct input_dev *input = ts->input;
+
+                dev_dbg(&ts->client->dev, "UP\n");
+
+                input_report_key(input, BTN_TOUCH, 0);
+                input_report_abs(input, ABS_PRESSURE, 0);
+                input_sync(input);
+
+                ts->pendown = 0;
+                enable_irq(ts->irq);
+        } else {
+                /* pen is still down, continue with the measurement */
+                dev_dbg(&ts->client->dev, "pen is still down\n");
+
+                tsc2007_read_values(ts);
+                tsc2007_send_event(ts);
+        }
+
+        spin_unlock_irq(&ts->lock);
+
+        return HRTIMER_NORESTART;
+}
+
+static irqreturn_t tsc2007_irq(int irq, void *handle)
+{
+        struct tsc2007 *ts = handle;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ts->lock, flags);
+
+        if (likely(ts->get_pendown_state())) {
+                disable_irq(ts->irq);
+                hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+                                        HRTIMER_MODE_REL);
+        }
+
+        if (ts->clear_penirq)
+                ts->clear_penirq();
+
+        spin_unlock_irqrestore(&ts->lock, flags);
+
+        return IRQ_HANDLED;
+}
+
+static int tsc2007_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+        struct tsc2007 *ts;
+        struct tsc2007_platform_data *pdata = pdata = client->dev.platform_data;
+        struct input_dev *input_dev;
+        int err;
+
+        if (!pdata) {
+                dev_err(&client->dev, "platform data is required!\n");
+                return -EINVAL;
+        }
+
+        if (!i2c_check_functionality(client->adapter,
+                                     I2C_FUNC_SMBUS_READ_WORD_DATA))
+                return -EIO;
+
+        ts = kzalloc(sizeof(struct tsc2007), GFP_KERNEL);
+        input_dev = input_allocate_device();
+        if (!ts || !input_dev) {
+                err = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        ts->client = client;
+        i2c_set_clientdata(client, ts);
+
+        ts->input = input_dev;
+
+        hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+        ts->timer.function = tsc2007_timer;
+
+        spin_lock_init(&ts->lock);
+
+        ts->model             = pdata->model;
+        ts->x_plate_ohms      = pdata->x_plate_ohms;
+        ts->get_pendown_state = pdata->get_pendown_state;
+        ts->clear_penirq      = pdata->clear_penirq;
+
+        pdata->init_platform_hw();
+
+        snprintf(ts->phys, sizeof(ts->phys), "%s/input0", client->dev.bus_id);
+
+        input_dev->name = "TSC2007 Touchscreen";
+        input_dev->phys = ts->phys;
+        input_dev->id.bustype = BUS_I2C;
+
+        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+
+        input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+        input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+        input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
+
+        tsc2007_read_values(ts);
+
+        ts->irq = client->irq;
+
+        err = request_irq(ts->irq, tsc2007_irq, 0,
+                        client->dev.driver->name, ts);
+        if (err < 0) {
+                dev_err(&client->dev, "irq %d busy?\n", ts->irq);
+                goto err_free_mem;
+        }
+
+        err = input_register_device(input_dev);
+        if (err)
+                goto err_free_irq;
+
+        dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);
+
+        return 0;
+
+ err_free_irq:
+        free_irq(ts->irq, ts);
+        hrtimer_cancel(&ts->timer);
+ err_free_mem:
+        input_free_device(input_dev);
+        kfree(ts);
+        return err;
+}
+
+static int tsc2007_remove(struct i2c_client *client)
+{
+        struct tsc2007  *ts = i2c_get_clientdata(client);
+        struct tsc2007_platform_data *pdata;
+
+        pdata = client->dev.platform_data;
+        pdata->exit_platform_hw();
+
+        free_irq(ts->irq, ts);
+        hrtimer_cancel(&ts->timer);
+        input_unregister_device(ts->input);
+        kfree(ts);
+
+        return 0;
+}
+
+static struct i2c_device_id tsc2007_idtable[] = {
+        { "tsc2007", 0 },
+        { }
+};
+
+MODULE_DEVICE_TABLE(i2c, tsc2007_idtable);
+
+static struct i2c_driver tsc2007_driver = {
+        .driver = {
+                .owner  = THIS_MODULE,
+                .name   = "tsc2007"
+        },
+        .id_table       = tsc2007_idtable,
+        .probe          = tsc2007_probe,
+        .remove         = tsc2007_remove,
+};
+
+static int __init tsc2007_init(void)
+{
+        return i2c_add_driver(&tsc2007_driver);
+}
+
+static void __exit tsc2007_exit(void)
+{
+        i2c_del_driver(&tsc2007_driver);
+}
+
+module_init(tsc2007_init);
+module_exit(tsc2007_exit);
+
+MODULE_AUTHOR("Kwangwoo Lee <kwlee@mtekvision.com>");
+MODULE_DESCRIPTION("TSC2007 TouchScreen Driver");
+MODULE_LICENSE("GPL");