clearpad_tm1217.c

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/*
 * clearpad_tm1217.c - Touch Screen driver for Synaptics Clearpad
 * TM1217 controller
 *
 * Copyright (C) 2008 Intel Corp
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; ifnot, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * Questions/Comments/Bug fixes to Ramesh Agarwal ([email protected])
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/i2c.h>
#include <linux/timer.h>
#include <linux/gpio.h>
#include <linux/hrtimer.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include "cp_tm1217.h"

#define CPTM1217_DEVICE_NAME        "cptm1217"
#define CPTM1217_DRIVER_NAME        CPTM1217_DEVICE_NAME

#define MAX_TOUCH_SUPPORTED     2
#define TOUCH_SUPPORTED         1
#define SAMPLING_FREQ           80  /* Frequency in HZ */
#define DELAY_BTWIN_SAMPLE      (1000 / SAMPLING_FREQ)
#define WAIT_FOR_RESPONSE       5   /* 5msec just works */
#define MAX_RETRIES         5   /* As above */
#define INCREMENTAL_DELAY       5   /* As above */

/* Regster Definitions */
#define TMA1217_DEV_STATUS      0x13    /* Device Status */
#define TMA1217_INT_STATUS      0x14    /* Interrupt Status */

/* Controller can detect up to 2 possible finger touches.
 * Each finger touch provides  12 bit X Y co-ordinates, the values are split
 * across 2 registers, and an 8 bit  Z value */
#define TMA1217_FINGER_STATE        0x18 /* Finger State */
#define TMA1217_FINGER1_X_HIGHER8   0x19 /* Higher 8 bit of X coordinate */
#define TMA1217_FINGER1_Y_HIGHER8   0x1A /* Higher 8 bit of Y coordinate */
#define TMA1217_FINGER1_XY_LOWER4   0x1B /* Lower 4 bits of X and Y */
#define TMA1217_FINGER1_Z_VALUE     0x1D /* 8 bit Z value for finger 1 */
#define TMA1217_FINGER2_X_HIGHER8   0x1E /* Higher 8 bit of X coordinate */
#define TMA1217_FINGER2_Y_HIGHER8   0x1F /* Higher 8 bit of Y coordinate */
#define TMA1217_FINGER2_XY_LOWER4   0x20 /* Lower 4 bits of X and Y */
#define TMA1217_FINGER2_Z_VALUE     0x22 /* 8 bit Z value for finger 2 */
#define TMA1217_DEVICE_CTRL     0x23 /* Device Control */
#define TMA1217_INTERRUPT_ENABLE    0x24 /* Interrupt Enable */
#define TMA1217_REPORT_MODE     0x2B /* Reporting Mode */
#define TMA1217_MAX_X_LOWER8        0x31 /* Bit 0-7 for Max X */
#define TMA1217_MAX_X_HIGHER4       0x32 /* Bit 8-11 for Max X */
#define TMA1217_MAX_Y_LOWER8        0x33 /* Bit 0-7 for Max Y */
#define TMA1217_MAX_Y_HIGHER4       0x34 /* Bit 8-11 for Max Y */
#define TMA1217_DEVICE_CMD_RESET    0x67 /* Device CMD reg for reset */
#define TMA1217_DEVICE_CMD_REZERO   0x69 /* Device CMD reg for rezero */

#define TMA1217_MANUFACTURER_ID     0x73 /* Manufacturer Id */
#define TMA1217_PRODUCT_FAMILY      0x75 /* Product Family */
#define TMA1217_FIRMWARE_REVISION   0x76 /* Firmware Revision */
#define TMA1217_SERIAL_NO_HIGH      0x7C /* Bit 8-15 of device serial no. */
#define TMA1217_SERIAL_NO_LOW       0x7D /* Bit 0-7 of device serial no. */
#define TMA1217_PRODUCT_ID_START    0x7E /* Start address for 10 byte ID */
#define TMA1217_DEVICE_CAPABILITY   0x8B /* Reporting capability */


/*
 * The touch position structure.
 */
struct touch_state {
    int x;
    int y;
    bool button;
};

/* Device Specific info given by the controller */
struct cp_dev_info {
    u16 maxX;
    u16 maxY;
};

/* Vendor related info given by the controller */
struct cp_vendor_info {
    u8  vendor_id;
    u8  product_family;
    u8  firmware_rev;
    u16 serial_no;
};

/*
 * Private structure to store the device details
 */
struct cp_tm1217_device {
    struct i2c_client   *client;
    struct device       *dev;
    struct cp_vendor_info   vinfo;
    struct cp_dev_info  dinfo;
    struct input_dev_info {
        char            phys[32];
        char            name[128];
        struct input_dev    *input;
        struct touch_state  touch;
    } cp_input_info[MAX_TOUCH_SUPPORTED];

    int thread_running;
    struct mutex    thread_mutex;

    int gpio;
};


/* The following functions are used to read/write registers on the device
 * as per the RMI prorocol. Technically, a page select should be written
 * before doing read/write but since the register offsets are below 0xFF
 * we can use the default value of page which is 0x00
 */
static int cp_tm1217_read(struct cp_tm1217_device *ts,
                u8 *req, int size)
{
    int i, retval;

    /* Send the address */
    retval = i2c_master_send(ts->client, &req[0], 1);
    if (retval != 1) {
        dev_err(ts->dev, "cp_tm1217: I2C send failed\n");
        return retval;
    }
    msleep(WAIT_FOR_RESPONSE);
    for (i = 0; i < MAX_RETRIES; i++) {
        retval = i2c_master_recv(ts->client, &req[1], size);
        if (retval == size) {
            break;
        } else {
            msleep(INCREMENTAL_DELAY);
            dev_dbg(ts->dev, "cp_tm1217: Retry count is %d\n", i);
        }
    }
    if (retval != size)
        dev_err(ts->dev, "cp_tm1217: Read from device failed\n");

    return retval;
}

static int cp_tm1217_write(struct cp_tm1217_device *ts,
                u8 *req, int size)
{
    int retval;

    /* Send the address and the data to be written */
    retval = i2c_master_send(ts->client, &req[0], size + 1);
    if (retval != size + 1) {
        dev_err(ts->dev, "cp_tm1217: I2C write  failed: %d\n", retval);
        return retval;
    }
    /* Wait for the write to complete. TBD why this is required */
    msleep(WAIT_FOR_RESPONSE);

    return size;
}

static int cp_tm1217_mask_interrupt(struct cp_tm1217_device *ts)
{
    u8 req[2];
    int retval;

    req[0] = TMA1217_INTERRUPT_ENABLE;
    req[1] = 0x0;
    retval = cp_tm1217_write(ts, req, 1);
    if (retval != 1)
        return -EIO;

    return 0;
}

static int cp_tm1217_unmask_interrupt(struct cp_tm1217_device *ts)
{
    u8 req[2];
    int retval;

    req[0] = TMA1217_INTERRUPT_ENABLE;
    req[1] = 0xa;
    retval = cp_tm1217_write(ts, req, 1);
    if (retval != 1)
        return -EIO;

    return 0;
}

static void process_touch(struct cp_tm1217_device *ts, int index)
{
    int retval;
    struct input_dev_info *input_info =
        (struct input_dev_info *)&ts->cp_input_info[index];
    u8 xy_data[6];

    if (index == 0)
        xy_data[0] = TMA1217_FINGER1_X_HIGHER8;
    else
        xy_data[0] = TMA1217_FINGER2_X_HIGHER8;

    retval = cp_tm1217_read(ts, xy_data, 5);
    if (retval < 5) {
        dev_err(ts->dev, "cp_tm1217: XY read from device failed\n");
        return;
    }

    /* Note: Currently not using the Z values but may be requried in
       the future. */
    input_info->touch.x = (xy_data[1] << 4)
                    | (xy_data[3] & 0x0F);
    input_info->touch.y = (xy_data[2] << 4)
                    | ((xy_data[3] & 0xF0) >> 4);
    input_report_abs(input_info->input, ABS_X, input_info->touch.x);
    input_report_abs(input_info->input, ABS_Y, input_info->touch.y);
    input_sync(input_info->input);
}

static void cp_tm1217_get_data(struct cp_tm1217_device *ts)
{
    u8 req[2];
    int retval, i, finger_touched = 0;

    do {
        req[0] = TMA1217_FINGER_STATE;
        retval = cp_tm1217_read(ts, req, 1);
        if (retval != 1) {
            dev_err(ts->dev,
                "cp_tm1217: Read from device failed\n");
            continue;
        }
        finger_touched = 0;
        /* Start sampling until the pressure is below
          threshold */
        for (i = 0; i < TOUCH_SUPPORTED; i++) {
            if (req[1] & 0x3) {
                finger_touched++;
                if (ts->cp_input_info[i].touch.button == 0) {
                    /* send the button touch event */
                    input_report_key(
                        ts->cp_input_info[i].input,
                        BTN_TOUCH, 1);
                    ts->cp_input_info[i].touch.button = 1;
                }
                process_touch(ts, i);
            } else {
                if (ts->cp_input_info[i].touch.button == 1) {
                    /* send the button release event */
                    input_report_key(
                        ts->cp_input_info[i].input,
                        BTN_TOUCH, 0);
                    input_sync(ts->cp_input_info[i].input);
                    ts->cp_input_info[i].touch.button = 0;
                }
            }
            req[1] = req[1] >> 2;
        }
        msleep(DELAY_BTWIN_SAMPLE);
    } while (finger_touched > 0);
}

static irqreturn_t cp_tm1217_sample_thread(int irq, void *handle)
{
    struct cp_tm1217_device *ts = (struct cp_tm1217_device *) handle;
    u8 req[2];
    int retval;

    /* Chedk if another thread is already running */
    mutex_lock(&ts->thread_mutex);
    if (ts->thread_running == 1) {
        mutex_unlock(&ts->thread_mutex);
        return IRQ_HANDLED;
    } else {
        ts->thread_running = 1;
        mutex_unlock(&ts->thread_mutex);
    }

    /* Mask the interrupts */
    retval = cp_tm1217_mask_interrupt(ts);

    /* Read the Interrupt Status register to find the cause of the
       Interrupt */
    req[0] = TMA1217_INT_STATUS;
    retval = cp_tm1217_read(ts, req, 1);
    if (retval != 1)
        goto exit_thread;

    if (!(req[1] & 0x8))
        goto exit_thread;

    cp_tm1217_get_data(ts);

exit_thread:
    /* Unmask the interrupts before going to sleep */
    retval = cp_tm1217_unmask_interrupt(ts);

    mutex_lock(&ts->thread_mutex);
    ts->thread_running = 0;
    mutex_unlock(&ts->thread_mutex);

    return IRQ_HANDLED;
}

static int cp_tm1217_init_data(struct cp_tm1217_device *ts)
{
    int retval;
    u8  req[2];

    /* Read the vendor id/ fw revision etc. Ignoring return check as this
       is non critical info  */
    req[0] = TMA1217_MANUFACTURER_ID;
    retval = cp_tm1217_read(ts, req, 1);
    ts->vinfo.vendor_id = req[1];

    req[0] = TMA1217_PRODUCT_FAMILY;
    retval = cp_tm1217_read(ts, req, 1);
    ts->vinfo.product_family = req[1];

    req[0] = TMA1217_FIRMWARE_REVISION;
    retval = cp_tm1217_read(ts, req, 1);
    ts->vinfo.firmware_rev = req[1];

    req[0] = TMA1217_SERIAL_NO_HIGH;
    retval = cp_tm1217_read(ts, req, 1);
    ts->vinfo.serial_no = (req[1] << 8);

    req[0] = TMA1217_SERIAL_NO_LOW;
    retval = cp_tm1217_read(ts, req, 1);
    ts->vinfo.serial_no = ts->vinfo.serial_no | req[1];

    req[0] = TMA1217_MAX_X_HIGHER4;
    retval = cp_tm1217_read(ts, req, 1);
    ts->dinfo.maxX = (req[1] & 0xF) << 8;

    req[0] = TMA1217_MAX_X_LOWER8;
    retval = cp_tm1217_read(ts, req, 1);
    ts->dinfo.maxX = ts->dinfo.maxX | req[1];

    req[0] = TMA1217_MAX_Y_HIGHER4;
    retval = cp_tm1217_read(ts, req, 1);
    ts->dinfo.maxY = (req[1] & 0xF) << 8;

    req[0] = TMA1217_MAX_Y_LOWER8;
    retval = cp_tm1217_read(ts, req, 1);
    ts->dinfo.maxY = ts->dinfo.maxY | req[1];

    return 0;

}

/*
 *  Set up a GPIO for use as the interrupt. We can't simply do this at
 *  boot time because the GPIO drivers themselves may not be around at
 *  boot/firmware set up time to do the work. Instead defer it to driver
 *  detection.
 */

static int cp_tm1217_setup_gpio_irq(struct cp_tm1217_device *ts)
{
    int retval;

    /* Hook up the irq handler */
    retval = gpio_request(ts->gpio, "cp_tm1217_touch");
    if (retval < 0) {
        dev_err(ts->dev, "cp_tm1217: GPIO request failed error %d\n",
                                retval);
        return retval;
    }

    retval = gpio_direction_input(ts->gpio);
    if (retval < 0) {
        dev_err(ts->dev,
        "cp_tm1217: GPIO direction configuration failed, error %d\n",
                                retval);
        gpio_free(ts->gpio);
        return retval;
    }

    retval = gpio_to_irq(ts->gpio);
    if (retval < 0) {
        dev_err(ts->dev,
            "cp_tm1217: GPIO to IRQ failed, error %d\n", retval);
        gpio_free(ts->gpio);
    }
    dev_dbg(ts->dev,
        "cp_tm1217: Got IRQ number is %d for GPIO %d\n",
        retval, ts->gpio);
    return retval;
}

static int cp_tm1217_probe(struct i2c_client *client,
            const struct i2c_device_id *id)
{
    struct cp_tm1217_device *ts;
    struct input_dev *input_dev;
    struct input_dev_info   *input_info;
    struct cp_tm1217_platform_data *pdata;
    u8 req[2];
    int i, retval;

    /* No pdata is fine - we then use "normal" IRQ mode */

    pdata = client->dev.platform_data;

    ts = kzalloc(sizeof(struct cp_tm1217_device), GFP_KERNEL);
    if (!ts) {
        dev_err(&client->dev,
            "cp_tm1217: Private Device Struct alloc failed\n");
        return -ENOMEM;
    }

    ts->client = client;
    ts->dev = &client->dev;
    i2c_set_clientdata(client, ts);

    ts->thread_running = 0;
    mutex_init(&ts->thread_mutex);

    /* Reset the Controller */
    req[0] = TMA1217_DEVICE_CMD_RESET;
    req[1] = 0x1;
    retval = cp_tm1217_write(ts, req, 1);
    if (retval != 1) {
        dev_err(ts->dev, "cp_tm1217: Controller reset failed\n");
        kfree(ts);
        return -EIO;
    }

    /* Clear up the interrupt status from reset. */
    req[0] = TMA1217_INT_STATUS;
    retval = cp_tm1217_read(ts, req, 1);

    /* Mask all the interrupts */
    retval = cp_tm1217_mask_interrupt(ts);

    /* Read the controller information */
    cp_tm1217_init_data(ts);

    /* The following code will register multiple event devices when
       multi-pointer is enabled, the code has not been tested
       with MPX */
    for (i = 0; i < TOUCH_SUPPORTED; i++) {
        input_dev = input_allocate_device();
        if (input_dev == NULL) {
            dev_err(ts->dev,
                "cp_tm1217:Input Device Struct alloc failed\n");
            retval = -ENOMEM;
            goto fail;
        }
        input_info = &ts->cp_input_info[i];
        snprintf(input_info->name, sizeof(input_info->name),
            "cp_tm1217_touchscreen_%d", i);
        input_dev->name = input_info->name;
        snprintf(input_info->phys, sizeof(input_info->phys),
            "%s/input%d", dev_name(&client->dev), i);

        input_dev->phys = input_info->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, ts->dinfo.maxX, 0, 0);
        input_set_abs_params(input_dev, ABS_Y, 0, ts->dinfo.maxY, 0, 0);

        retval = input_register_device(input_dev);
        if (retval) {
            dev_err(ts->dev,
                "Input dev registration failed for %s\n",
                    input_dev->name);
            input_free_device(input_dev);
            goto fail;
        }
        input_info->input = input_dev;
    }

    /* Setup the reporting mode to send an interrupt only when
       finger arrives or departs. */
    req[0] = TMA1217_REPORT_MODE;
    req[1] = 0x02;
    retval = cp_tm1217_write(ts, req, 1);

    /* Setup the device to no sleep mode for now and make it configured */
    req[0] = TMA1217_DEVICE_CTRL;
    req[1] = 0x84;
    retval = cp_tm1217_write(ts, req, 1);

    /* Check for the status of the device */
    req[0] = TMA1217_DEV_STATUS;
    retval = cp_tm1217_read(ts, req, 1);
    if (req[1] != 0) {
        dev_err(ts->dev,
            "cp_tm1217: Device Status 0x%x != 0: config failed\n",
            req[1]);

        retval = -EIO;
        goto fail;
    }

    if (pdata && pdata->gpio) {
        ts->gpio = pdata->gpio;
        retval = cp_tm1217_setup_gpio_irq(ts);
    } else
        retval = client->irq;

    if (retval < 0) {
        dev_err(ts->dev, "cp_tm1217: GPIO request failed error %d\n",
                                retval);
        goto fail;
    }

    client->irq = retval;


    retval = request_threaded_irq(client->irq,
        NULL, cp_tm1217_sample_thread,
        IRQF_TRIGGER_FALLING, "cp_tm1217_touch", ts);
    if (retval < 0) {
        dev_err(ts->dev, "cp_tm1217: Request IRQ error %d\n", retval);
        goto fail_gpio;
    }

    /* Unmask the interrupts */
    retval = cp_tm1217_unmask_interrupt(ts);
    if (retval == 0)
        return 0;

    free_irq(client->irq, ts);
fail_gpio:
    if (ts->gpio)
        gpio_free(ts->gpio);
fail:
    /* Clean up before returning failure */
    for (i = 0; i < TOUCH_SUPPORTED; i++) {
        if (ts->cp_input_info[i].input) {
            input_unregister_device(ts->cp_input_info[i].input);
            input_free_device(ts->cp_input_info[i].input);
        }
    }
    kfree(ts);
    return retval;

}

/*
 * cp_tm1217 suspend
 *
 */
static int cp_tm1217_suspend(struct i2c_client *client, pm_message_t mesg)
{
    struct cp_tm1217_device *ts = i2c_get_clientdata(client);
    u8 req[2];
    int retval;

    /* Put the controller to sleep */
    req[0] = TMA1217_DEVICE_CTRL;
    retval = cp_tm1217_read(ts, req, 1);
    req[1] = (req[1] & 0xF8) | 0x1;
    retval = cp_tm1217_write(ts, req, 1);

    if (device_may_wakeup(&client->dev))
        enable_irq_wake(client->irq);

    return 0;
}

/*
 * cp_tm1217_resume
 *
 */
static int cp_tm1217_resume(struct i2c_client *client)
{
    struct cp_tm1217_device *ts = i2c_get_clientdata(client);
    u8 req[2];
    int retval;

    /* Take the controller out of sleep */
    req[0] = TMA1217_DEVICE_CTRL;
    retval = cp_tm1217_read(ts, req, 1);
    req[1] = (req[1] & 0xF8) | 0x4;
    retval = cp_tm1217_write(ts, req, 1);

    /* Restore the register settings sinc the power to the
       could have been cut off */

    /* Setup the reporting mode to send an interrupt only when
       finger arrives or departs. */
    req[0] = TMA1217_REPORT_MODE;
    req[1] = 0x02;
    retval = cp_tm1217_write(ts, req, 1);

    /* Setup the device to no sleep mode for now and make it configured */
    req[0] = TMA1217_DEVICE_CTRL;
    req[1] = 0x84;
    retval = cp_tm1217_write(ts, req, 1);

    /* Setup the interrupt mask */
    retval = cp_tm1217_unmask_interrupt(ts);

    if (device_may_wakeup(&client->dev))
        disable_irq_wake(client->irq);

    return 0;
}

/*
 * cp_tm1217_remove
 *
 */
static int cp_tm1217_remove(struct i2c_client *client)
{
    struct cp_tm1217_device *ts = i2c_get_clientdata(client);
    int i;

    free_irq(client->irq, ts);
    if (ts->gpio)
        gpio_free(ts->gpio);
    for (i = 0; i < TOUCH_SUPPORTED; i++)
        input_unregister_device(ts->cp_input_info[i].input);
    kfree(ts);
    return 0;
}

static struct i2c_device_id cp_tm1217_idtable[] = {
    { CPTM1217_DEVICE_NAME, 0 },
    { }
};

MODULE_DEVICE_TABLE(i2c, cp_tm1217_idtable);

static struct i2c_driver cp_tm1217_driver = {
    .driver = {
        .owner  = THIS_MODULE,
        .name   = CPTM1217_DRIVER_NAME,
    },
    .id_table   = cp_tm1217_idtable,
    .probe      = cp_tm1217_probe,
    .remove     = cp_tm1217_remove,
    .suspend    = cp_tm1217_suspend,
    .resume     = cp_tm1217_resume,
};

module_i2c_driver(cp_tm1217_driver);

MODULE_AUTHOR("Ramesh Agarwal <[email protected]>");
MODULE_DESCRIPTION("Synaptics TM1217 TouchScreen Driver");
MODULE_LICENSE("GPL v2");