touchscreen-meddling.patch

[linux-2.6/openmoko-kernel/knife-kernel.git] / drivers / input / touchscreen / s3c2410_ts.c

/*
 * 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; 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 (c) 2004 Arnaud Patard <arnaud.patard@rtp-net.org>
 * iPAQ H1940 touchscreen support
 *
 * ChangeLog
 *
 * 2004-09-05: Herbert Pötzl <herbert@13thfloor.at>
 *      - added clock (de-)allocation code
 *
 * 2005-03-06: Arnaud Patard <arnaud.patard@rtp-net.org>
 *      - h1940_ -> s3c2410 (this driver is now also used on the n30
 *        machines :P)
 *      - Debug messages are now enabled with the config option
 *        TOUCHSCREEN_S3C2410_DEBUG
 *      - Changed the way the value are read
 *      - Input subsystem should now work
 *      - Use ioremap and readl/writel
 *
 * 2005-03-23: Arnaud Patard <arnaud.patard@rtp-net.org>
 *      - Make use of some undocumented features of the touchscreen
 *        controller
 *
 * 2007-05-23: Harald Welte <laforge@openmoko.org>
 *      - Add proper support for S32440
 *
 * 2008-06-18: Andy Green <andy@openmoko.com>
 *      - Outlier removal
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>

#include <asm/arch/regs-gpio.h>
#include <asm/arch/ts.h>

#include <asm/plat-s3c/regs-adc.h>

/* For ts.dev.id.version */
#define S3C2410TSVERSION        0x0101

#define TSC_SLEEP  (S3C2410_ADCTSC_PULL_UP_DISABLE | S3C2410_ADCTSC_XY_PST(0))

#define WAIT4INT(x)  (((x)<<8) | \
                     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 DEBUG_LVL    KERN_DEBUG

MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>");
MODULE_DESCRIPTION("s3c2410 touchscreen driver");
MODULE_LICENSE("GPL");

/*
 * Definitions & global arrays.
 */


static char *s3c2410ts_name = "s3c2410 TouchScreen";

/*
 * Per-touchscreen data.
 */

struct s3c2410ts_sample {
        int x;
        int y;
};

struct s3c2410ts {
        struct input_dev *dev;
        long xp;
        long yp;
        int count;
        int shift;
        int extent;  /* 1 << shift */

        /* the raw sample fifo is a lightweight way to track a running average
         * of all taken samples.  "running average" here means that it gives
         * correct average for each sample, not only at the end of block of
         * samples
         */
        int excursion_filter_len;
        struct s3c2410ts_sample *raw_sample_fifo;
        int head_raw_fifo;
        int tail_raw_fifo;
        struct s3c2410ts_sample raw_running_avg;
        int reject_threshold_vs_avg;
        int flag_previous_exceeded_threshold;
};

static struct s3c2410ts ts;
static void __iomem *base_addr;

static void clear_raw_fifo(void)
{
        ts.head_raw_fifo = 0;
        ts.tail_raw_fifo = 0;
        ts.raw_running_avg.x = 0;
        ts.raw_running_avg.y = 0;
        ts.flag_previous_exceeded_threshold = 0;
}


static inline void s3c2410_ts_connect(void)
{
        s3c2410_gpio_cfgpin(S3C2410_GPG12, S3C2410_GPG12_XMON);
        s3c2410_gpio_cfgpin(S3C2410_GPG13, S3C2410_GPG13_nXPON);
        s3c2410_gpio_cfgpin(S3C2410_GPG14, S3C2410_GPG14_YMON);
        s3c2410_gpio_cfgpin(S3C2410_GPG15, S3C2410_GPG15_nYPON);
}

static void touch_timer_fire(unsigned long data)
{
        unsigned long data0;
        unsigned long data1;
        int updown;

        data0 = readl(base_addr + S3C2410_ADCDAT0);
        data1 = readl(base_addr + S3C2410_ADCDAT1);

        updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) &&
                                            (!(data1 & S3C2410_ADCDAT0_UPDOWN));

        if (updown) {
                if (ts.count != 0) {
                        ts.xp >>= ts.shift;
                        ts.yp >>= ts.shift;

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG
                        {
                                struct timeval tv;

                                do_gettimeofday(&tv);
                                printk(DEBUG_LVL "T:%06d, X:%03ld, Y:%03ld\n",
                                                 (int)tv.tv_usec, ts.xp, ts.yp);
                        }
#endif

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

                        input_report_key(ts.dev, BTN_TOUCH, 1);
                        input_report_abs(ts.dev, ABS_PRESSURE, 1);
                        input_sync(ts.dev);
                }

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

                writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
                                                      base_addr+S3C2410_ADCTSC);
                writel(readl(base_addr+S3C2410_ADCCON) |
                         S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
        } else {
                ts.count = 0;

                input_report_key(ts.dev, BTN_TOUCH, 0);
                input_report_abs(ts.dev, ABS_PRESSURE, 0);
                input_sync(ts.dev);

                writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);
        }
}

static struct timer_list touch_timer =
                TIMER_INITIALIZER(touch_timer_fire, 0, 0);

static irqreturn_t stylus_updown(int irq, void *dev_id)
{
        unsigned long data0;
        unsigned long data1;
        int updown;

        data0 = readl(base_addr+S3C2410_ADCDAT0);
        data1 = readl(base_addr+S3C2410_ADCDAT1);

        updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) &&
                                            (!(data1 & S3C2410_ADCDAT0_UPDOWN));

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

        if (updown)
                touch_timer_fire(0);

        return IRQ_HANDLED;
}


static irqreturn_t stylus_action(int irq, void *dev_id)
{
        unsigned long x;
        unsigned long y;
        int length = (ts.head_raw_fifo - ts.tail_raw_fifo) & (ts.extent - 1);
        int scaled_avg_x = ts.raw_running_avg.x / length;
        int scaled_avg_y = ts.raw_running_avg.y / length;

        x = readl(base_addr + S3C2410_ADCDAT0) & S3C2410_ADCDAT0_XPDATA_MASK;
        y = readl(base_addr + S3C2410_ADCDAT1) & S3C2410_ADCDAT1_YPDATA_MASK;

        /* we appear to accept every sample into both the running average FIFO
         * and the summing average.  BUT, if the last sample crossed a
         * machine-set threshold, each time we do a beauty contest
         * on the new sample comparing if it is closer to the running
         * average and the previous sample.  If it is closer to the previous
         * suspicious sample, we assume the change is real and accept both
         * if the new sample has returned to being closer to the average than
         * the previous sample, we take the previous sample as an excursion
         * and overwrite it in both the running average and summing average.
         */

        if (ts.flag_previous_exceeded_threshold)
                /* new one closer to "nonconformist" previous, or average?
                 * Pythagoras?  Who?  Don't need it because large excursion
                 * will be accounted for correctly this way
                 */
                if ((abs(x - scaled_avg_x) + abs(y - scaled_avg_y)) <
                    (abs(x - ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                          (ts.extent - 1)].x) +
                     abs(y - ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                         (ts.extent - 1)].y))) {
                        /* it's closer to average, reject previous as a one-
                         * shot excursion, by overwriting it
                         */
                        ts.xp += x - ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                             (ts.extent - 1)].x;
                        ts.yp += y - ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                             (ts.extent - 1)].y;
                        ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                         (ts.extent - 1)].x = x;
                        ts.raw_sample_fifo[(ts.head_raw_fifo - 1) &
                                                         (ts.extent - 1)].y = y;
                        /* no new sample: replaced previous, so we are done */
                        goto completed;
                }
                /* else it was closer to nonconformist previous: it's likely
                 * a genuine consistent move then.
                 * Keep previous and add new guy.
                 */

        if ((x >= scaled_avg_x - ts.reject_threshold_vs_avg) &&
            (x <= scaled_avg_x + ts.reject_threshold_vs_avg) &&
            (y >= scaled_avg_y - ts.reject_threshold_vs_avg) &&
            (y <= scaled_avg_y + ts.reject_threshold_vs_avg))
                ts.flag_previous_exceeded_threshold = 0;
        else
                ts.flag_previous_exceeded_threshold = 1;

        /* accepted */
        ts.xp += x;
        ts.yp += y;
        ts.count++;

        /* remove oldest sample from avg when we have full pipeline */
        if (((ts.head_raw_fifo + 1) & (ts.extent - 1)) == ts.tail_raw_fifo) {
                ts.raw_running_avg.x -= ts.raw_sample_fifo[ts.tail_raw_fifo].x;
                ts.raw_running_avg.y -= ts.raw_sample_fifo[ts.tail_raw_fifo].y;
                ts.tail_raw_fifo = (ts.tail_raw_fifo + 1) & (ts.extent - 1);
        }
        /* always add current sample to fifo and average */
        ts.raw_sample_fifo[ts.head_raw_fifo].x = x;
        ts.raw_sample_fifo[ts.head_raw_fifo].y = y;
        ts.raw_running_avg.x += x;
        ts.raw_running_avg.y += y;
        ts.head_raw_fifo = (ts.head_raw_fifo + 1) & (ts.extent - 1);

completed:
        if (ts.count >= (1 << ts.shift)) {
                mod_timer(&touch_timer, jiffies + 1);
                writel(WAIT4INT(1), base_addr+S3C2410_ADCTSC);
                goto bail;
        }

        writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST,
                                                      base_addr+S3C2410_ADCTSC);
        writel(readl(base_addr+S3C2410_ADCCON) |
                         S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);

bail:
        return IRQ_HANDLED;
}

static struct clk       *adc_clock;

/*
 * The functions for inserting/removing us as a module.
 */

static int __init s3c2410ts_probe(struct platform_device *pdev)
{
        int rc;
        struct s3c2410_ts_mach_info *info;
        struct input_dev *input_dev;

        info = (struct s3c2410_ts_mach_info *)pdev->dev.platform_data;

        if (!info)
        {
                dev_err(&pdev->dev, "Hm... too bad: no platform data for ts\n");
                return -EINVAL;
        }

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG
        printk(DEBUG_LVL "Entering s3c2410ts_init\n");
#endif

        adc_clock = clk_get(NULL, "adc");
        if (!adc_clock) {
                dev_err(&pdev->dev, "failed to get adc clock source\n");
                return -ENOENT;
        }
        clk_enable(adc_clock);

#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG
        printk(DEBUG_LVL "got and enabled clock\n");
#endif

        base_addr = ioremap(S3C2410_PA_ADC,0x20);
        if (base_addr == NULL) {
                dev_err(&pdev->dev, "Failed to remap register block\n");
                return -ENOMEM;
        }


        /* If we acutally are a S3C2410: Configure GPIOs */
        if (!strcmp(pdev->name, "s3c2410-ts"))
                s3c2410_ts_connect();

        if ((info->presc & 0xff) > 0)
                writel(S3C2410_ADCCON_PRSCEN |
                       S3C2410_ADCCON_PRSCVL(info->presc&0xFF),
                                                    base_addr + S3C2410_ADCCON);
        else
                writel(0, base_addr+S3C2410_ADCCON);


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

        writel(WAIT4INT(0), base_addr + S3C2410_ADCTSC);

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

        if (!input_dev) {
                dev_err(&pdev->dev, "Unable to allocate the input device\n");
                return -ENOMEM;
        }

        ts.dev = input_dev;
        ts.dev->evbit[0] = BIT_MASK(EV_SYN) | BIT_MASK(EV_KEY) |
                           BIT_MASK(EV_ABS);
        ts.dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
        input_set_abs_params(ts.dev, ABS_X, 0, 0x3FF, 0, 0);
        input_set_abs_params(ts.dev, ABS_Y, 0, 0x3FF, 0, 0);
        input_set_abs_params(ts.dev, ABS_PRESSURE, 0, 1, 0, 0);

        ts.dev->private = &ts;
        ts.dev->name = s3c2410ts_name;
        ts.dev->id.bustype = BUS_RS232;
        ts.dev->id.vendor = 0xDEAD;
        ts.dev->id.product = 0xBEEF;
        ts.dev->id.version = S3C2410TSVERSION;

        ts.shift = info->oversampling_shift;
        ts.extent = 1 << info->oversampling_shift;
        ts.reject_threshold_vs_avg = info->reject_threshold_vs_avg;
        ts.excursion_filter_len = 1 << info->excursion_filter_len_bits;

        ts.raw_sample_fifo = kmalloc(sizeof(struct s3c2410ts_sample) *
                                           ts.excursion_filter_len, GFP_KERNEL);
        clear_raw_fifo();

        /* Get irqs */
        if (request_irq(IRQ_ADC, stylus_action, IRQF_SAMPLE_RANDOM,
                                                    "s3c2410_action", ts.dev)) {
                dev_err(&pdev->dev, "Could not allocate ts IRQ_ADC !\n");
                iounmap(base_addr);
                return -EIO;
        }
        if (request_irq(IRQ_TC, stylus_updown, IRQF_SAMPLE_RANDOM,
                        "s3c2410_action", ts.dev)) {
                dev_err(&pdev->dev, "Could not allocate ts IRQ_TC !\n");
                free_irq(IRQ_ADC, ts.dev);
                iounmap(base_addr);
                return -EIO;
        }

        dev_info(&pdev->dev, "successfully loaded\n");

        /* All went ok, so register to the input system */
        rc = input_register_device(ts.dev);
        if (rc) {
                free_irq(IRQ_TC, ts.dev);
                free_irq(IRQ_ADC, ts.dev);
                clk_disable(adc_clock);
                iounmap(base_addr);
                return -EIO;
        }

        return 0;
}

static int s3c2410ts_remove(struct platform_device *pdev)
{
        disable_irq(IRQ_ADC);
        disable_irq(IRQ_TC);
        free_irq(IRQ_TC,ts.dev);
        free_irq(IRQ_ADC,ts.dev);

        if (adc_clock) {
                clk_disable(adc_clock);
                clk_put(adc_clock);
                adc_clock = NULL;
        }

        kfree(ts.raw_sample_fifo);

        input_unregister_device(ts.dev);
        iounmap(base_addr);

        return 0;
}

#ifdef CONFIG_PM
static int s3c2410ts_suspend(struct platform_device *pdev, pm_message_t state)
{
        writel(TSC_SLEEP, base_addr+S3C2410_ADCTSC);
        writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_STDBM,
               base_addr+S3C2410_ADCCON);

        disable_irq(IRQ_ADC);
        disable_irq(IRQ_TC);

        clk_disable(adc_clock);

        return 0;
}

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

        clk_enable(adc_clock);
        mdelay(1);

        clear_raw_fifo();

        enable_irq(IRQ_ADC);
        enable_irq(IRQ_TC);

        if ((info->presc&0xff) > 0)
                writel(S3C2410_ADCCON_PRSCEN |
                       S3C2410_ADCCON_PRSCVL(info->presc&0xFF),
                                                      base_addr+S3C2410_ADCCON);
        else
                writel(0,base_addr+S3C2410_ADCCON);

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

        writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);

        return 0;
}

#else
#define s3c2410ts_suspend NULL
#define s3c2410ts_resume  NULL
#endif

static struct platform_driver s3c2410ts_driver = {
       .driver         = {
               .name   = "s3c2410-ts",
               .owner  = THIS_MODULE,
       },
       .probe          = s3c2410ts_probe,
       .remove         = s3c2410ts_remove,
       .suspend        = s3c2410ts_suspend,
       .resume         = s3c2410ts_resume,

};

static struct platform_driver s3c2440ts_driver = {
       .driver         = {
               .name   = "s3c2440-ts",
               .owner  = THIS_MODULE,
       },
       .probe          = s3c2410ts_probe,
       .remove         = s3c2410ts_remove,
       .suspend        = s3c2410ts_suspend,
       .resume         = s3c2410ts_resume,

};

static int __init s3c2410ts_init(void)
{
        int rc;

        rc = platform_driver_register(&s3c2410ts_driver);
        if (rc < 0)
                return rc;

        rc = platform_driver_register(&s3c2440ts_driver);
        if (rc < 0)
                platform_driver_unregister(&s3c2410ts_driver);

        return rc;
}

static void __exit s3c2410ts_exit(void)
{
        platform_driver_unregister(&s3c2440ts_driver);
        platform_driver_unregister(&s3c2410ts_driver);
}

module_init(s3c2410ts_init);
module_exit(s3c2410ts_exit);

/*
    Local variables:
        compile-command: "make ARCH=arm CROSS_COMPILE=/usr/local/arm/3.3.2/bin/arm-linux- -k -C ../../.."
        c-basic-offset: 8
    End:
*/