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corgi_ts.c

/*
 *  Touchscreen driver for Sharp SL-C7xx and SL-Cxx00 models
 *
 *  Copyright (c) 2004-2005 Richard Purdie
 *
 *  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/delay.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/irq.h>

#include <asm/arch/sharpsl.h>
#include <asm/arch/hardware.h>
#include <asm/arch/pxa-regs.h>


#define PWR_MODE_ACTIVE       0
#define PWR_MODE_SUSPEND      1

#define X_AXIS_MAX            3830
#define X_AXIS_MIN            150
#define Y_AXIS_MAX            3830
#define Y_AXIS_MIN            190
#define PRESSURE_MIN          0
#define PRESSURE_MAX          15000

struct ts_event {
      short pressure;
      short x;
      short y;
};

struct corgi_ts {
      struct input_dev *input;
      struct timer_list timer;
      struct ts_event tc;
      int pendown;
      int power_mode;
      int irq_gpio;
      struct corgits_machinfo *machinfo;
};

#ifdef CONFIG_PXA25x
#define CCNT(a)         asm volatile ("mrc p14, 0, %0, C1, C0, 0" : "=r"(a))
#define PMNC_GET(x)     asm volatile ("mrc p14, 0, %0, C0, C0, 0" : "=r"(x))
#define PMNC_SET(x)     asm volatile ("mcr p14, 0, %0, C0, C0, 0" : : "r"(x))
#endif
#ifdef CONFIG_PXA27x
#define CCNT(a)         asm volatile ("mrc p14, 0, %0, C1, C1, 0" : "=r"(a))
#define PMNC_GET(x)     asm volatile ("mrc p14, 0, %0, C0, C1, 0" : "=r"(x))
#define PMNC_SET(x)     asm volatile ("mcr p14, 0, %0, C0, C1, 0" : : "r"(x))
#endif

/* ADS7846 Touch Screen Controller bit definitions */
#define ADSCTRL_PD0           (1u << 0)   /* PD0 */
#define ADSCTRL_PD1           (1u << 1)   /* PD1 */
#define ADSCTRL_DFR           (1u << 2)   /* SER/DFR */
#define ADSCTRL_MOD           (1u << 3)   /* Mode */
#define ADSCTRL_ADR_SH  4     /* Address setting */
#define ADSCTRL_STS           (1u << 7)   /* Start Bit */

/* External Functions */
extern unsigned int get_clk_frequency_khz(int info);

static unsigned long calc_waittime(struct corgi_ts *corgi_ts)
{
      unsigned long hsync_len = corgi_ts->machinfo->get_hsync_len();

      if (hsync_len)
            return get_clk_frequency_khz(0)*1000/hsync_len;
      else
            return 0;
}

static int sync_receive_data_send_cmd(struct corgi_ts *corgi_ts, int doRecive, int doSend,
            unsigned int address, unsigned long wait_time)
{
      unsigned long timer1 = 0, timer2, pmnc = 0;
      int pos = 0;

      if (wait_time && doSend) {
            PMNC_GET(pmnc);
            if (!(pmnc & 0x01))
                  PMNC_SET(0x01);

            /* polling HSync */
            corgi_ts->machinfo->wait_hsync();
            /* get CCNT */
            CCNT(timer1);
      }

      if (doRecive)
            pos = corgi_ssp_ads7846_get();

      if (doSend) {
            int cmd = ADSCTRL_PD0 | ADSCTRL_PD1 | (address << ADSCTRL_ADR_SH) | ADSCTRL_STS;
            /* dummy command */
            corgi_ssp_ads7846_put(cmd);
            corgi_ssp_ads7846_get();

            if (wait_time) {
                  /* Wait after HSync */
                  CCNT(timer2);
                  if (timer2-timer1 > wait_time) {
                        /* too slow - timeout, try again */
                        corgi_ts->machinfo->wait_hsync();
                        /* get OSCR */
                        CCNT(timer1);
                        /* Wait after HSync */
                        CCNT(timer2);
                  }
                  while (timer2 - timer1 < wait_time)
                        CCNT(timer2);
            }
            corgi_ssp_ads7846_put(cmd);
            if (wait_time && !(pmnc & 0x01))
                  PMNC_SET(pmnc);
      }
      return pos;
}

static int read_xydata(struct corgi_ts *corgi_ts)
{
      unsigned int x, y, z1, z2;
      unsigned long flags, wait_time;

      /* critical section */
      local_irq_save(flags);
      corgi_ssp_ads7846_lock();
      wait_time = calc_waittime(corgi_ts);

      /* Y-axis */
      sync_receive_data_send_cmd(corgi_ts, 0, 1, 1u, wait_time);

      /* Y-axis */
      sync_receive_data_send_cmd(corgi_ts, 1, 1, 1u, wait_time);

      /* X-axis */
      y = sync_receive_data_send_cmd(corgi_ts, 1, 1, 5u, wait_time);

      /* Z1 */
      x = sync_receive_data_send_cmd(corgi_ts, 1, 1, 3u, wait_time);

      /* Z2 */
      z1 = sync_receive_data_send_cmd(corgi_ts, 1, 1, 4u, wait_time);
      z2 = sync_receive_data_send_cmd(corgi_ts, 1, 0, 4u, wait_time);

      /* Power-Down Enable */
      corgi_ssp_ads7846_put((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      corgi_ssp_ads7846_get();

      corgi_ssp_ads7846_unlock();
      local_irq_restore(flags);

      if (x== 0 || y == 0 || z1 == 0 || (x * (z2 - z1) / z1) >= 15000) {
            corgi_ts->tc.pressure = 0;
            return 0;
      }

      corgi_ts->tc.x = x;
      corgi_ts->tc.y = y;
      corgi_ts->tc.pressure = (x * (z2 - z1)) / z1;
      return 1;
}

static void new_data(struct corgi_ts *corgi_ts)
{
      struct input_dev *dev = corgi_ts->input;

      if (corgi_ts->power_mode != PWR_MODE_ACTIVE)
            return;

      if (!corgi_ts->tc.pressure && corgi_ts->pendown == 0)
            return;

      input_report_abs(dev, ABS_X, corgi_ts->tc.x);
      input_report_abs(dev, ABS_Y, corgi_ts->tc.y);
      input_report_abs(dev, ABS_PRESSURE, corgi_ts->tc.pressure);
      input_report_key(dev, BTN_TOUCH, corgi_ts->pendown);
      input_sync(dev);
}

static void ts_interrupt_main(struct corgi_ts *corgi_ts, int isTimer)
{
      if ((GPLR(IRQ_TO_GPIO(corgi_ts->irq_gpio)) & GPIO_bit(IRQ_TO_GPIO(corgi_ts->irq_gpio))) == 0) {
            /* Disable Interrupt */
            set_irq_type(corgi_ts->irq_gpio, IRQT_NOEDGE);
            if (read_xydata(corgi_ts)) {
                  corgi_ts->pendown = 1;
                  new_data(corgi_ts);
            }
            mod_timer(&corgi_ts->timer, jiffies + HZ / 100);
      } else {
            if (corgi_ts->pendown == 1 || corgi_ts->pendown == 2) {
                  mod_timer(&corgi_ts->timer, jiffies + HZ / 100);
                  corgi_ts->pendown++;
                  return;
            }

            if (corgi_ts->pendown) {
                  corgi_ts->tc.pressure = 0;
                  new_data(corgi_ts);
            }

            /* Enable Falling Edge */
            set_irq_type(corgi_ts->irq_gpio, IRQT_FALLING);
            corgi_ts->pendown = 0;
      }
}

static void corgi_ts_timer(unsigned long data)
{
      struct corgi_ts *corgits_data = (struct corgi_ts *) data;

      ts_interrupt_main(corgits_data, 1);
}

static irqreturn_t ts_interrupt(int irq, void *dev_id)
{
      struct corgi_ts *corgits_data = dev_id;

      ts_interrupt_main(corgits_data, 0);
      return IRQ_HANDLED;
}

#ifdef CONFIG_PM
static int corgits_suspend(struct platform_device *dev, pm_message_t state)
{
      struct corgi_ts *corgi_ts = platform_get_drvdata(dev);

      if (corgi_ts->pendown) {
            del_timer_sync(&corgi_ts->timer);
            corgi_ts->tc.pressure = 0;
            new_data(corgi_ts);
            corgi_ts->pendown = 0;
      }
      corgi_ts->power_mode = PWR_MODE_SUSPEND;

      corgi_ssp_ads7846_putget((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);

      return 0;
}

static int corgits_resume(struct platform_device *dev)
{
      struct corgi_ts *corgi_ts = platform_get_drvdata(dev);

      corgi_ssp_ads7846_putget((4u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      /* Enable Falling Edge */
      set_irq_type(corgi_ts->irq_gpio, IRQT_FALLING);
      corgi_ts->power_mode = PWR_MODE_ACTIVE;

      return 0;
}
#else
#define corgits_suspend       NULL
#define corgits_resume        NULL
#endif

static int __init corgits_probe(struct platform_device *pdev)
{
      struct corgi_ts *corgi_ts;
      struct input_dev *input_dev;
      int err = -ENOMEM;

      corgi_ts = kzalloc(sizeof(struct corgi_ts), GFP_KERNEL);
      input_dev = input_allocate_device();
      if (!corgi_ts || !input_dev)
            goto fail1;

      platform_set_drvdata(pdev, corgi_ts);

      corgi_ts->machinfo = pdev->dev.platform_data;
      corgi_ts->irq_gpio = platform_get_irq(pdev, 0);

      if (corgi_ts->irq_gpio < 0) {
            err = -ENODEV;
            goto fail1;
      }

      corgi_ts->input = input_dev;

      init_timer(&corgi_ts->timer);
      corgi_ts->timer.data = (unsigned long) corgi_ts;
      corgi_ts->timer.function = corgi_ts_timer;

      input_dev->name = "Corgi Touchscreen";
      input_dev->phys = "corgits/input0";
      input_dev->id.bustype = BUS_HOST;
      input_dev->id.vendor = 0x0001;
      input_dev->id.product = 0x0002;
      input_dev->id.version = 0x0100;
      input_dev->dev.parent = &pdev->dev;

      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, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
      input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
      input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN, PRESSURE_MAX, 0, 0);

      pxa_gpio_mode(IRQ_TO_GPIO(corgi_ts->irq_gpio) | GPIO_IN);

      /* Initiaize ADS7846 Difference Reference mode */
      corgi_ssp_ads7846_putget((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      mdelay(5);
      corgi_ssp_ads7846_putget((3u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      mdelay(5);
      corgi_ssp_ads7846_putget((4u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      mdelay(5);
      corgi_ssp_ads7846_putget((5u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
      mdelay(5);

      if (request_irq(corgi_ts->irq_gpio, ts_interrupt, IRQF_DISABLED, "ts", corgi_ts)) {
            err = -EBUSY;
            goto fail1;
      }

      err = input_register_device(corgi_ts->input);
      if (err)
            goto fail2;

      corgi_ts->power_mode = PWR_MODE_ACTIVE;

      /* Enable Falling Edge */
      set_irq_type(corgi_ts->irq_gpio, IRQT_FALLING);

      return 0;

 fail2:     free_irq(corgi_ts->irq_gpio, corgi_ts);
 fail1:     input_free_device(input_dev);
      kfree(corgi_ts);
      return err;
}

static int corgits_remove(struct platform_device *pdev)
{
      struct corgi_ts *corgi_ts = platform_get_drvdata(pdev);

      free_irq(corgi_ts->irq_gpio, corgi_ts);
      del_timer_sync(&corgi_ts->timer);
      corgi_ts->machinfo->put_hsync();
      input_unregister_device(corgi_ts->input);
      kfree(corgi_ts);
      return 0;
}

static struct platform_driver corgits_driver = {
      .probe            = corgits_probe,
      .remove           = corgits_remove,
      .suspend    = corgits_suspend,
      .resume           = corgits_resume,
      .driver           = {
            .name = "corgi-ts",
      },
};

static int __devinit corgits_init(void)
{
      return platform_driver_register(&corgits_driver);
}

static void __exit corgits_exit(void)
{
      platform_driver_unregister(&corgits_driver);
}

module_init(corgits_init);
module_exit(corgits_exit);

MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
MODULE_DESCRIPTION("Corgi TouchScreen Driver");
MODULE_LICENSE("GPL");

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