cyttsp_core.c

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/*
 * Core Source for:
 * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
 * For use with Cypress Txx3xx parts.
 * Supported parts include:
 * CY8CTST341
 * CY8CTMA340
 *
 * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
 * Copyright (C) 2012 Javier Martinez Canillas <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2, and only version 2, as published by the
 * Free Software Foundation.
 *
 * 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; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contact Cypress Semiconductor at www.cypress.com <[email protected]>
 *
 */

#include <linux/delay.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#include "cyttsp_core.h"

/* Bootloader number of command keys */
#define CY_NUM_BL_KEYS      8

/* helpers */
#define GET_NUM_TOUCHES(x)      ((x) & 0x0F)
#define IS_LARGE_AREA(x)        (((x) & 0x10) >> 4)
#define IS_BAD_PKT(x)           ((x) & 0x20)
#define IS_VALID_APP(x)         ((x) & 0x01)
#define IS_OPERATIONAL_ERR(x)       ((x) & 0x3F)
#define GET_HSTMODE(reg)        (((reg) & 0x70) >> 4)
#define GET_BOOTLOADERMODE(reg)     (((reg) & 0x10) >> 4)

#define CY_REG_BASE         0x00
#define CY_REG_ACT_DIST         0x1E
#define CY_REG_ACT_INTRVL       0x1D
#define CY_REG_TCH_TMOUT        (CY_REG_ACT_INTRVL + 1)
#define CY_REG_LP_INTRVL        (CY_REG_TCH_TMOUT + 1)
#define CY_MAXZ             255
#define CY_DELAY_DFLT           20 /* ms */
#define CY_DELAY_MAX            500
#define CY_ACT_DIST_DFLT        0xF8
#define CY_HNDSHK_BIT           0x80
/* device mode bits */
#define CY_OPERATE_MODE         0x00
#define CY_SYSINFO_MODE         0x10
/* power mode select bits */
#define CY_SOFT_RESET_MODE      0x01 /* return to Bootloader mode */
#define CY_DEEP_SLEEP_MODE      0x02
#define CY_LOW_POWER_MODE       0x04

/* Slots management */
#define CY_MAX_FINGER           4
#define CY_MAX_ID           16

static const u8 bl_command[] = {
    0x00,           /* file offset */
    0xFF,           /* command */
    0xA5,           /* exit bootloader command */
    0, 1, 2, 3, 4, 5, 6, 7  /* default keys */
};

static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
                u8 length, void *buf)
{
    int error;
    int tries;

    for (tries = 0; tries < CY_NUM_RETRY; tries++) {
        error = ts->bus_ops->read(ts, command, length, buf);
        if (!error)
            return 0;

        msleep(CY_DELAY_DFLT);
    }

    return -EIO;
}

static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
                 u8 length, void *buf)
{
    int error;
    int tries;

    for (tries = 0; tries < CY_NUM_RETRY; tries++) {
        error = ts->bus_ops->write(ts, command, length, buf);
        if (!error)
            return 0;

        msleep(CY_DELAY_DFLT);
    }

    return -EIO;
}

static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
{
    return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
}

static int cyttsp_load_bl_regs(struct cyttsp *ts)
{
    memset(&ts->bl_data, 0, sizeof(ts->bl_data));
    ts->bl_data.bl_status = 0x10;

    return ttsp_read_block_data(ts, CY_REG_BASE,
                    sizeof(ts->bl_data), &ts->bl_data);
}

static int cyttsp_exit_bl_mode(struct cyttsp *ts)
{
    int error;
    u8 bl_cmd[sizeof(bl_command)];

    memcpy(bl_cmd, bl_command, sizeof(bl_command));
    if (ts->pdata->bl_keys)
        memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
            ts->pdata->bl_keys, sizeof(bl_command));

    error = ttsp_write_block_data(ts, CY_REG_BASE,
                      sizeof(bl_cmd), bl_cmd);
    if (error)
        return error;

    /* wait for TTSP Device to complete the operation */
    msleep(CY_DELAY_DFLT);

    error = cyttsp_load_bl_regs(ts);
    if (error)
        return error;

    if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
        return -EIO;

    return 0;
}

static int cyttsp_set_operational_mode(struct cyttsp *ts)
{
    int error;

    error = ttsp_send_command(ts, CY_OPERATE_MODE);
    if (error)
        return error;

    /* wait for TTSP Device to complete switch to Operational mode */
    error = ttsp_read_block_data(ts, CY_REG_BASE,
                     sizeof(ts->xy_data), &ts->xy_data);
    if (error)
        return error;

    return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
}

static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
{
    int error;

    memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));

    /* switch to sysinfo mode */
    error = ttsp_send_command(ts, CY_SYSINFO_MODE);
    if (error)
        return error;

    /* read sysinfo registers */
    msleep(CY_DELAY_DFLT);
    error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
                      &ts->sysinfo_data);
    if (error)
        return error;

    if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
        return -EIO;

    return 0;
}

static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
{
    int retval = 0;

    if (ts->pdata->act_intrvl != CY_ACT_INTRVL_DFLT ||
        ts->pdata->tch_tmout != CY_TCH_TMOUT_DFLT ||
        ts->pdata->lp_intrvl != CY_LP_INTRVL_DFLT) {

        u8 intrvl_ray[] = {
            ts->pdata->act_intrvl,
            ts->pdata->tch_tmout,
            ts->pdata->lp_intrvl
        };

        /* set intrvl registers */
        retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
                    sizeof(intrvl_ray), intrvl_ray);
        msleep(CY_DELAY_DFLT);
    }

    return retval;
}

static int cyttsp_soft_reset(struct cyttsp *ts)
{
    unsigned long timeout;
    int retval;

    /* wait for interrupt to set ready completion */
    INIT_COMPLETION(ts->bl_ready);
    ts->state = CY_BL_STATE;

    enable_irq(ts->irq);

    retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
    if (retval)
        goto out;

    timeout = wait_for_completion_timeout(&ts->bl_ready,
            msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX));
    retval = timeout ? 0 : -EIO;

out:
    ts->state = CY_IDLE_STATE;
    disable_irq(ts->irq);
    return retval;
}

static int cyttsp_act_dist_setup(struct cyttsp *ts)
{
    u8 act_dist_setup = ts->pdata->act_dist;

    /* Init gesture; active distance setup */
    return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
                sizeof(act_dist_setup), &act_dist_setup);
}

static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
{
    ids[0] = xy_data->touch12_id >> 4;
    ids[1] = xy_data->touch12_id & 0xF;
    ids[2] = xy_data->touch34_id >> 4;
    ids[3] = xy_data->touch34_id & 0xF;
}

static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
                           int idx)
{
    switch (idx) {
    case 0:
        return &xy_data->tch1;
    case 1:
        return &xy_data->tch2;
    case 2:
        return &xy_data->tch3;
    case 3:
        return &xy_data->tch4;
    default:
        return NULL;
    }
}

static void cyttsp_report_tchdata(struct cyttsp *ts)
{
    struct cyttsp_xydata *xy_data = &ts->xy_data;
    struct input_dev *input = ts->input;
    int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
    const struct cyttsp_tch *tch;
    int ids[CY_MAX_ID];
    int i;
    DECLARE_BITMAP(used, CY_MAX_ID);

    if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
        /* terminate all active tracks */
        num_tch = 0;
        dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
    } else if (num_tch > CY_MAX_FINGER) {
        /* terminate all active tracks */
        num_tch = 0;
        dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
    } else if (IS_BAD_PKT(xy_data->tt_mode)) {
        /* terminate all active tracks */
        num_tch = 0;
        dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
    }

    cyttsp_extract_track_ids(xy_data, ids);

    bitmap_zero(used, CY_MAX_ID);

    for (i = 0; i < num_tch; i++) {
        tch = cyttsp_get_tch(xy_data, i);

        input_mt_slot(input, ids[i]);
        input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
        input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
        input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
        input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);

        __set_bit(ids[i], used);
    }

    for (i = 0; i < CY_MAX_ID; i++) {
        if (test_bit(i, used))
            continue;

        input_mt_slot(input, i);
        input_mt_report_slot_state(input, MT_TOOL_FINGER, false);
    }

    input_sync(input);
}

static irqreturn_t cyttsp_irq(int irq, void *handle)
{
    struct cyttsp *ts = handle;
    int error;

    if (unlikely(ts->state == CY_BL_STATE)) {
        complete(&ts->bl_ready);
        goto out;
    }

    /* Get touch data from CYTTSP device */
    error = ttsp_read_block_data(ts, CY_REG_BASE,
                 sizeof(struct cyttsp_xydata), &ts->xy_data);
    if (error)
        goto out;

    /* provide flow control handshake */
    if (ts->pdata->use_hndshk) {
        error = ttsp_send_command(ts,
                ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);
        if (error)
            goto out;
    }

    if (unlikely(ts->state == CY_IDLE_STATE))
        goto out;

    if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
        /*
         * TTSP device has reset back to bootloader mode.
         * Restore to operational mode.
         */
        error = cyttsp_exit_bl_mode(ts);
        if (error) {
            dev_err(ts->dev,
                "Could not return to operational mode, err: %d\n",
                error);
            ts->state = CY_IDLE_STATE;
        }
    } else {
        cyttsp_report_tchdata(ts);
    }

out:
    return IRQ_HANDLED;
}

static int cyttsp_power_on(struct cyttsp *ts)
{
    int error;

    error = cyttsp_soft_reset(ts);
    if (error)
        return error;

    error = cyttsp_load_bl_regs(ts);
    if (error)
        return error;

    if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
        IS_VALID_APP(ts->bl_data.bl_status)) {
        error = cyttsp_exit_bl_mode(ts);
        if (error)
            return error;
    }

    if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
        IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
        return -ENODEV;
    }

    error = cyttsp_set_sysinfo_mode(ts);
    if (error)
        return error;

    error = cyttsp_set_sysinfo_regs(ts);
    if (error)
        return error;

    error = cyttsp_set_operational_mode(ts);
    if (error)
        return error;

    /* init active distance */
    error = cyttsp_act_dist_setup(ts);
    if (error)
        return error;

    ts->state = CY_ACTIVE_STATE;

    return 0;
}

static int cyttsp_enable(struct cyttsp *ts)
{
    int error;

    /*
     * The device firmware can wake on an I2C or SPI memory slave
     * address match. So just reading a register is sufficient to
     * wake up the device. The first read attempt will fail but it
     * will wake it up making the second read attempt successful.
     */
    error = ttsp_read_block_data(ts, CY_REG_BASE,
                     sizeof(ts->xy_data), &ts->xy_data);
    if (error)
        return error;

    if (GET_HSTMODE(ts->xy_data.hst_mode))
        return -EIO;

    enable_irq(ts->irq);

    return 0;
}

static int cyttsp_disable(struct cyttsp *ts)
{
    int error;

    error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
    if (error)
        return error;

    disable_irq(ts->irq);

    return 0;
}

#ifdef CONFIG_PM_SLEEP
static int cyttsp_suspend(struct device *dev)
{
    struct cyttsp *ts = dev_get_drvdata(dev);
    int retval = 0;

    mutex_lock(&ts->input->mutex);

    if (ts->input->users) {
        retval = cyttsp_disable(ts);
        if (retval == 0)
            ts->suspended = true;
    }

    mutex_unlock(&ts->input->mutex);

    return retval;
}

static int cyttsp_resume(struct device *dev)
{
    struct cyttsp *ts = dev_get_drvdata(dev);

    mutex_lock(&ts->input->mutex);

    if (ts->input->users)
        cyttsp_enable(ts);

    ts->suspended = false;

    mutex_unlock(&ts->input->mutex);

    return 0;
}

#endif

SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);
EXPORT_SYMBOL_GPL(cyttsp_pm_ops);

static int cyttsp_open(struct input_dev *dev)
{
    struct cyttsp *ts = input_get_drvdata(dev);
    int retval = 0;

    if (!ts->suspended)
        retval = cyttsp_enable(ts);

    return retval;
}

static void cyttsp_close(struct input_dev *dev)
{
    struct cyttsp *ts = input_get_drvdata(dev);

    if (!ts->suspended)
        cyttsp_disable(ts);
}

struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
                struct device *dev, int irq, size_t xfer_buf_size)
{
    const struct cyttsp_platform_data *pdata = dev->platform_data;
    struct cyttsp *ts;
    struct input_dev *input_dev;
    int error;

    if (!pdata || !pdata->name || irq <= 0) {
        error = -EINVAL;
        goto err_out;
    }

    ts = kzalloc(sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
    input_dev = input_allocate_device();
    if (!ts || !input_dev) {
        error = -ENOMEM;
        goto err_free_mem;
    }

    ts->dev = dev;
    ts->input = input_dev;
    ts->pdata = dev->platform_data;
    ts->bus_ops = bus_ops;
    ts->irq = irq;

    init_completion(&ts->bl_ready);
    snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));

    if (pdata->init) {
        error = pdata->init();
        if (error) {
            dev_err(ts->dev, "platform init failed, err: %d\n",
                error);
            goto err_free_mem;
        }
    }

    input_dev->name = pdata->name;
    input_dev->phys = ts->phys;
    input_dev->id.bustype = bus_ops->bustype;
    input_dev->dev.parent = ts->dev;

    input_dev->open = cyttsp_open;
    input_dev->close = cyttsp_close;

    input_set_drvdata(input_dev, ts);

    __set_bit(EV_ABS, input_dev->evbit);
    input_set_abs_params(input_dev, ABS_MT_POSITION_X,
                 0, pdata->maxx, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_POSITION_Y,
                 0, pdata->maxy, 0, 0);
    input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
                 0, CY_MAXZ, 0, 0);

    input_mt_init_slots(input_dev, CY_MAX_ID, 0);

    error = request_threaded_irq(ts->irq, NULL, cyttsp_irq,
                     IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                     pdata->name, ts);
    if (error) {
        dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
            ts->irq, error);
        goto err_platform_exit;
    }

    disable_irq(ts->irq);

    error = cyttsp_power_on(ts);
    if (error)
        goto err_free_irq;

    error = input_register_device(input_dev);
    if (error) {
        dev_err(ts->dev, "failed to register input device: %d\n",
            error);
        goto err_free_irq;
    }

    return ts;

err_free_irq:
    free_irq(ts->irq, ts);
err_platform_exit:
    if (pdata->exit)
        pdata->exit();
err_free_mem:
    input_free_device(input_dev);
    kfree(ts);
err_out:
    return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(cyttsp_probe);

void cyttsp_remove(struct cyttsp *ts)
{
    free_irq(ts->irq, ts);
    input_unregister_device(ts->input);
    if (ts->pdata->exit)
        ts->pdata->exit();
    kfree(ts);
}
EXPORT_SYMBOL_GPL(cyttsp_remove);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
MODULE_AUTHOR("Cypress");