s3c2410_ts.c

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/*
 * Samsung S3C24XX touchscreen driver
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the term of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Copyright 2004 Arnaud Patard <[email protected]>
 * Copyright 2008 Ben Dooks <[email protected]>
 * Copyright 2009 Simtec Electronics <[email protected]>
 *
 * Additional work by Herbert Pötzl <[email protected]> and
 * Harald Welte <[email protected]>
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/io.h>

#include <plat/adc.h>
#include <plat/regs-adc.h>
#include <linux/platform_data/touchscreen-s3c2410.h>

#define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))

#define INT_DOWN    (0)
#define INT_UP      (1 << 8)

#define WAIT4INT    (S3C2410_ADCTSC_YM_SEN | \
             S3C2410_ADCTSC_YP_SEN | \
             S3C2410_ADCTSC_XP_SEN | \
             S3C2410_ADCTSC_XY_PST(3))

#define AUTOPST     (S3C2410_ADCTSC_YM_SEN | \
             S3C2410_ADCTSC_YP_SEN | \
             S3C2410_ADCTSC_XP_SEN | \
             S3C2410_ADCTSC_AUTO_PST | \
             S3C2410_ADCTSC_XY_PST(0))

#define FEAT_PEN_IRQ    (1 << 0)    /* HAS ADCCLRINTPNDNUP */

/* Per-touchscreen data. */

struct s3c2410ts {
    struct s3c_adc_client *client;
    struct device *dev;
    struct input_dev *input;
    struct clk *clock;
    void __iomem *io;
    unsigned long xp;
    unsigned long yp;
    int irq_tc;
    int count;
    int shift;
    int features;
};

static struct s3c2410ts ts;

static inline bool get_down(unsigned long data0, unsigned long data1)
{
    /* returns true if both data values show stylus down */
    return (!(data0 & S3C2410_ADCDAT0_UPDOWN) &&
        !(data1 & S3C2410_ADCDAT0_UPDOWN));
}

static void touch_timer_fire(unsigned long data)
{
    unsigned long data0;
    unsigned long data1;
    bool down;

    data0 = readl(ts.io + S3C2410_ADCDAT0);
    data1 = readl(ts.io + S3C2410_ADCDAT1);

    down = get_down(data0, data1);

    if (down) {
        if (ts.count == (1 << ts.shift)) {
            ts.xp >>= ts.shift;
            ts.yp >>= ts.shift;

            dev_dbg(ts.dev, "%s: X=%lu, Y=%lu, count=%d\n",
                __func__, ts.xp, ts.yp, ts.count);

            input_report_abs(ts.input, ABS_X, ts.xp);
            input_report_abs(ts.input, ABS_Y, ts.yp);

            input_report_key(ts.input, BTN_TOUCH, 1);
            input_sync(ts.input);

            ts.xp = 0;
            ts.yp = 0;
            ts.count = 0;
        }

        s3c_adc_start(ts.client, 0, 1 << ts.shift);
    } else {
        ts.xp = 0;
        ts.yp = 0;
        ts.count = 0;

        input_report_key(ts.input, BTN_TOUCH, 0);
        input_sync(ts.input);

        writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);
    }
}

static DEFINE_TIMER(touch_timer, touch_timer_fire, 0, 0);

static irqreturn_t stylus_irq(int irq, void *dev_id)
{
    unsigned long data0;
    unsigned long data1;
    bool down;

    data0 = readl(ts.io + S3C2410_ADCDAT0);
    data1 = readl(ts.io + S3C2410_ADCDAT1);

    down = get_down(data0, data1);

    /* TODO we should never get an interrupt with down set while
     * the timer is running, but maybe we ought to verify that the
     * timer isn't running anyways. */

    if (down)
        s3c_adc_start(ts.client, 0, 1 << ts.shift);
    else
        dev_dbg(ts.dev, "%s: count=%d\n", __func__, ts.count);

    if (ts.features & FEAT_PEN_IRQ) {
        /* Clear pen down/up interrupt */
        writel(0x0, ts.io + S3C64XX_ADCCLRINTPNDNUP);
    }

    return IRQ_HANDLED;
}

static void s3c24xx_ts_conversion(struct s3c_adc_client *client,
                  unsigned data0, unsigned data1,
                  unsigned *left)
{
    dev_dbg(ts.dev, "%s: %d,%d\n", __func__, data0, data1);

    ts.xp += data0;
    ts.yp += data1;

    ts.count++;

    /* From tests, it seems that it is unlikely to get a pen-up
     * event during the conversion process which means we can
     * ignore any pen-up events with less than the requisite
     * count done.
     *
     * In several thousand conversions, no pen-ups where detected
     * before count completed.
     */
}

static void s3c24xx_ts_select(struct s3c_adc_client *client, unsigned select)
{
    if (select) {
        writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
               ts.io + S3C2410_ADCTSC);
    } else {
        mod_timer(&touch_timer, jiffies+1);
        writel(WAIT4INT | INT_UP, ts.io + S3C2410_ADCTSC);
    }
}

static int __devinit s3c2410ts_probe(struct platform_device *pdev)
{
    struct s3c2410_ts_mach_info *info;
    struct device *dev = &pdev->dev;
    struct input_dev *input_dev;
    struct resource *res;
    int ret = -EINVAL;

    /* Initialise input stuff */
    memset(&ts, 0, sizeof(struct s3c2410ts));

    ts.dev = dev;

    info = pdev->dev.platform_data;
    if (!info) {
        dev_err(dev, "no platform data, cannot attach\n");
        return -EINVAL;
    }

    dev_dbg(dev, "initialising touchscreen\n");

    ts.clock = clk_get(dev, "adc");
    if (IS_ERR(ts.clock)) {
        dev_err(dev, "cannot get adc clock source\n");
        return -ENOENT;
    }

    clk_enable(ts.clock);
    dev_dbg(dev, "got and enabled clocks\n");

    ts.irq_tc = ret = platform_get_irq(pdev, 0);
    if (ret < 0) {
        dev_err(dev, "no resource for interrupt\n");
        goto err_clk;
    }

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res) {
        dev_err(dev, "no resource for registers\n");
        ret = -ENOENT;
        goto err_clk;
    }

    ts.io = ioremap(res->start, resource_size(res));
    if (ts.io == NULL) {
        dev_err(dev, "cannot map registers\n");
        ret = -ENOMEM;
        goto err_clk;
    }

    /* inititalise the gpio */
    if (info->cfg_gpio)
        info->cfg_gpio(to_platform_device(ts.dev));

    ts.client = s3c_adc_register(pdev, s3c24xx_ts_select,
                     s3c24xx_ts_conversion, 1);
    if (IS_ERR(ts.client)) {
        dev_err(dev, "failed to register adc client\n");
        ret = PTR_ERR(ts.client);
        goto err_iomap;
    }

    /* Initialise registers */
    if ((info->delay & 0xffff) > 0)
        writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);

    writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);

    input_dev = input_allocate_device();
    if (!input_dev) {
        dev_err(dev, "Unable to allocate the input device !!\n");
        ret = -ENOMEM;
        goto err_iomap;
    }

    ts.input = input_dev;
    ts.input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
    ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
    input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
    input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);

    ts.input->name = "S3C24XX TouchScreen";
    ts.input->id.bustype = BUS_HOST;
    ts.input->id.vendor = 0xDEAD;
    ts.input->id.product = 0xBEEF;
    ts.input->id.version = 0x0102;

    ts.shift = info->oversampling_shift;
    ts.features = platform_get_device_id(pdev)->driver_data;

    ret = request_irq(ts.irq_tc, stylus_irq, 0,
              "s3c2410_ts_pen", ts.input);
    if (ret) {
        dev_err(dev, "cannot get TC interrupt\n");
        goto err_inputdev;
    }

    dev_info(dev, "driver attached, registering input device\n");

    /* All went ok, so register to the input system */
    ret = input_register_device(ts.input);
    if (ret < 0) {
        dev_err(dev, "failed to register input device\n");
        ret = -EIO;
        goto err_tcirq;
    }

    return 0;

 err_tcirq:
    free_irq(ts.irq_tc, ts.input);
 err_inputdev:
    input_free_device(ts.input);
 err_iomap:
    iounmap(ts.io);
 err_clk:
    del_timer_sync(&touch_timer);
    clk_put(ts.clock);
    return ret;
}

static int __devexit s3c2410ts_remove(struct platform_device *pdev)
{
    free_irq(ts.irq_tc, ts.input);
    del_timer_sync(&touch_timer);

    clk_disable(ts.clock);
    clk_put(ts.clock);

    input_unregister_device(ts.input);
    iounmap(ts.io);

    return 0;
}

#ifdef CONFIG_PM
static int s3c2410ts_suspend(struct device *dev)
{
    writel(TSC_SLEEP, ts.io + S3C2410_ADCTSC);
    disable_irq(ts.irq_tc);
    clk_disable(ts.clock);

    return 0;
}

static int s3c2410ts_resume(struct device *dev)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct s3c2410_ts_mach_info *info = pdev->dev.platform_data;

    clk_enable(ts.clock);
    enable_irq(ts.irq_tc);

    /* Initialise registers */
    if ((info->delay & 0xffff) > 0)
        writel(info->delay & 0xffff, ts.io + S3C2410_ADCDLY);

    writel(WAIT4INT | INT_DOWN, ts.io + S3C2410_ADCTSC);

    return 0;
}

static const struct dev_pm_ops s3c_ts_pmops = {
    .suspend    = s3c2410ts_suspend,
    .resume     = s3c2410ts_resume,
};
#endif

static struct platform_device_id s3cts_driver_ids[] = {
    { "s3c2410-ts", 0 },
    { "s3c2440-ts", 0 },
    { "s3c64xx-ts", FEAT_PEN_IRQ },
    { }
};
MODULE_DEVICE_TABLE(platform, s3cts_driver_ids);

static struct platform_driver s3c_ts_driver = {
    .driver         = {
        .name   = "samsung-ts",
        .owner  = THIS_MODULE,
#ifdef CONFIG_PM
        .pm = &s3c_ts_pmops,
#endif
    },
    .id_table   = s3cts_driver_ids,
    .probe      = s3c2410ts_probe,
    .remove     = __devexit_p(s3c2410ts_remove),
};
module_platform_driver(s3c_ts_driver);

MODULE_AUTHOR("Arnaud Patard <[email protected]>, "
          "Ben Dooks <[email protected]>, "
          "Simtec Electronics <[email protected]>");
MODULE_DESCRIPTION("S3C24XX Touchscreen driver");
MODULE_LICENSE("GPL v2");