/*
   * linux/drivers/input/keyboard/omap-keypad.c
   *
   * OMAP Keypad Driver
   *
   * Copyright (C) 2003 Nokia Corporation
   * Written by Timo Teräs <ext-timo.teras@nokia.com>
   *
   * Added support for H2 & H3 Keypad
   * Copyright (C) 2004 Texas Instruments
   *
   * 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
   */
  
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/types.h>
  #include <linux/input.h>
  #include <linux/kernel.h>
  #include <linux/delay.h>
  #include <linux/platform_device.h>
  #include <linux/mutex.h>
  #include <linux/errno.h>
  #include <linux/slab.h>
  #include <linux/gpio.h>
  #include <linux/platform_data/gpio-omap.h>
  #include <linux/platform_data/keypad-omap.h>
  
  #undef NEW_BOARD_LEARNING_MODE
  
  static void omap_kp_tasklet(unsigned long);
  static void omap_kp_timer(unsigned long);
  
  static unsigned char keypad_state[8];
  static DEFINE_MUTEX(kp_enable_mutex);
  static int kp_enable = 1;
  static int kp_cur_group = -1;
  
  struct omap_kp {
  	struct input_dev *input;
  	struct timer_list timer;
  	int irq;
  	unsigned int rows;
  	unsigned int cols;
  	unsigned long delay;
  	unsigned int debounce;
  	unsigned short keymap[];
  };
  
  static DECLARE_TASKLET_DISABLED(kp_tasklet, omap_kp_tasklet, 0);
  
  static unsigned int *row_gpios;
  static unsigned int *col_gpios;
  
  #ifdef CONFIG_ARCH_OMAP2
  static void set_col_gpio_val(struct omap_kp *omap_kp, u8 value)
  {
  	int col;
  
  	for (col = 0; col < omap_kp->cols; col++)
  		gpio_set_value(col_gpios[col], value & (1 << col));
  }
  
  static u8 get_row_gpio_val(struct omap_kp *omap_kp)
  {
  	int row;
  	u8 value = 0;
  
  	for (row = 0; row < omap_kp->rows; row++) {
  		if (gpio_get_value(row_gpios[row]))
  			value |= (1 << row);
  	}
  	return value;
  }
  #else
  #define		set_col_gpio_val(x, y)	do {} while (0)
  #define		get_row_gpio_val(x)	0
  #endif
  
  static irqreturn_t omap_kp_interrupt(int irq, void *dev_id)
  {
  	/* disable keyboard interrupt and schedule for handling */
  	omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  
  	tasklet_schedule(&kp_tasklet);
  
  	return IRQ_HANDLED;
  }
  
  static void omap_kp_timer(unsigned long data)
  {
  	tasklet_schedule(&kp_tasklet);
  }
  
  static void omap_kp_scan_keypad(struct omap_kp *omap_kp, unsigned char *state)
  {
  	int col = 0;
  
  	/* disable keyboard interrupt and schedule for handling */
  	omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  
  	/* read the keypad status */
  	omap_writew(0xff, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);
  	for (col = 0; col < omap_kp->cols; col++) {
  		omap_writew(~(1 << col) & 0xff,
  			    OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);
  
  		udelay(omap_kp->delay);
  
  		state[col] = ~omap_readw(OMAP1_MPUIO_BASE +
  					 OMAP_MPUIO_KBR_LATCH) & 0xff;
  	}
  	omap_writew(0x00, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBC);
  	udelay(2);
  }
  
  static void omap_kp_tasklet(unsigned long data)
  {
  	struct omap_kp *omap_kp_data = (struct omap_kp *) data;
  	unsigned short *keycodes = omap_kp_data->input->keycode;
  	unsigned int row_shift = get_count_order(omap_kp_data->cols);
  	unsigned char new_state[8], changed, key_down = 0;
  	int col, row;
  	int spurious = 0;
  
  	/* check for any changes */
  	omap_kp_scan_keypad(omap_kp_data, new_state);
  
  	/* check for changes and print those */
  	for (col = 0; col < omap_kp_data->cols; col++) {
  		changed = new_state[col] ^ keypad_state[col];
  		key_down |= new_state[col];
  		if (changed == 0)
  			continue;
  
  		for (row = 0; row < omap_kp_data->rows; row++) {
  			int key;
  			if (!(changed & (1 << row)))
  				continue;
  #ifdef NEW_BOARD_LEARNING_MODE
  			printk(KERN_INFO "omap-keypad: key %d-%d %s
  ", col,
  			       row, (new_state[col] & (1 << row)) ?
  			       "pressed" : "released");
  #else
  			key = keycodes[MATRIX_SCAN_CODE(row, col, row_shift)];
  			if (key < 0) {
  				printk(KERN_WARNING
  				      "omap-keypad: Spurious key event %d-%d
  ",
  				       col, row);
  				/* We scan again after a couple of seconds */
  				spurious = 1;
  				continue;
  			}
  
  			if (!(kp_cur_group == (key & GROUP_MASK) ||
  			      kp_cur_group == -1))
  				continue;
  
  			kp_cur_group = key & GROUP_MASK;
  			input_report_key(omap_kp_data->input, key & ~GROUP_MASK,
  					 new_state[col] & (1 << row));
  #endif
  		}
  	}
  	input_sync(omap_kp_data->input);
  	memcpy(keypad_state, new_state, sizeof(keypad_state));
  
  	if (key_down) {
  		int delay = HZ / 20;
  		/* some key is pressed - keep irq disabled and use timer
  		 * to poll the keypad */
  		if (spurious)
  			delay = 2 * HZ;
  		mod_timer(&omap_kp_data->timer, jiffies + delay);
  	} else {
  		/* enable interrupts */
  		omap_writew(0, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  		kp_cur_group = -1;
  	}
  }
  
  static ssize_t omap_kp_enable_show(struct device *dev,
  				   struct device_attribute *attr, char *buf)
  {
  	return sprintf(buf, "%u
  ", kp_enable);
  }
  
  static ssize_t omap_kp_enable_store(struct device *dev, struct device_attribute *attr,
  				    const char *buf, size_t count)
  {
  	struct omap_kp *omap_kp = dev_get_drvdata(dev);
  	int state;
  
  	if (sscanf(buf, "%u", &state) != 1)
  		return -EINVAL;
  
  	if ((state != 1) && (state != 0))
  		return -EINVAL;
  
  	mutex_lock(&kp_enable_mutex);
  	if (state != kp_enable) {
  		if (state)
  			enable_irq(omap_kp->irq);
  		else
  			disable_irq(omap_kp->irq);
  		kp_enable = state;
  	}
  	mutex_unlock(&kp_enable_mutex);
  
  	return strnlen(buf, count);
  }
  
  static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, omap_kp_enable_show, omap_kp_enable_store);
  
  #ifdef CONFIG_PM
  static int omap_kp_suspend(struct platform_device *dev, pm_message_t state)
  {
  	/* Nothing yet */
  
  	return 0;
  }
  
  static int omap_kp_resume(struct platform_device *dev)
  {
  	/* Nothing yet */
  
  	return 0;
  }
  #else
  #define omap_kp_suspend	NULL
  #define omap_kp_resume	NULL
  #endif
  
  static int omap_kp_probe(struct platform_device *pdev)
  {
  	struct omap_kp *omap_kp;
  	struct input_dev *input_dev;
  	struct omap_kp_platform_data *pdata = dev_get_platdata(&pdev->dev);
  	int i, col_idx, row_idx, ret;
  	unsigned int row_shift, keycodemax;
  
  	if (!pdata->rows || !pdata->cols || !pdata->keymap_data) {
  		printk(KERN_ERR "No rows, cols or keymap_data from pdata
  ");
  		return -EINVAL;
  	}
  
  	row_shift = get_count_order(pdata->cols);
  	keycodemax = pdata->rows << row_shift;
  
  	omap_kp = kzalloc(sizeof(struct omap_kp) +
  			keycodemax * sizeof(unsigned short), GFP_KERNEL);
  	input_dev = input_allocate_device();
  	if (!omap_kp || !input_dev) {
  		kfree(omap_kp);
  		input_free_device(input_dev);
  		return -ENOMEM;
  	}
  
  	platform_set_drvdata(pdev, omap_kp);
  
  	omap_kp->input = input_dev;
  
  	/* Disable the interrupt for the MPUIO keyboard */
  	omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  
  	if (pdata->delay)
  		omap_kp->delay = pdata->delay;
  
  	if (pdata->row_gpios && pdata->col_gpios) {
  		row_gpios = pdata->row_gpios;
  		col_gpios = pdata->col_gpios;
  	}
  
  	omap_kp->rows = pdata->rows;
  	omap_kp->cols = pdata->cols;
  
  	col_idx = 0;
  	row_idx = 0;
  
  	setup_timer(&omap_kp->timer, omap_kp_timer, (unsigned long)omap_kp);
  
  	/* get the irq and init timer*/
  	tasklet_enable(&kp_tasklet);
  	kp_tasklet.data = (unsigned long) omap_kp;
  
  	ret = device_create_file(&pdev->dev, &dev_attr_enable);
  	if (ret < 0)
  		goto err2;
  
  	/* setup input device */
  	input_dev->name = "omap-keypad";
  	input_dev->phys = "omap-keypad/input0";
  	input_dev->dev.parent = &pdev->dev;
  
  	input_dev->id.bustype = BUS_HOST;
  	input_dev->id.vendor = 0x0001;
  	input_dev->id.product = 0x0001;
  	input_dev->id.version = 0x0100;
  
  	if (pdata->rep)
  		__set_bit(EV_REP, input_dev->evbit);
  
  	ret = matrix_keypad_build_keymap(pdata->keymap_data, NULL,
  					 pdata->rows, pdata->cols,
  					 omap_kp->keymap, input_dev);
  	if (ret < 0)
  		goto err3;
  
  	ret = input_register_device(omap_kp->input);
  	if (ret < 0) {
  		printk(KERN_ERR "Unable to register omap-keypad input device
  ");
  		goto err3;
  	}
  
  	if (pdata->dbounce)
  		omap_writew(0xff, OMAP1_MPUIO_BASE + OMAP_MPUIO_GPIO_DEBOUNCING);
  
  	/* scan current status and enable interrupt */
  	omap_kp_scan_keypad(omap_kp, keypad_state);
  	omap_kp->irq = platform_get_irq(pdev, 0);
  	if (omap_kp->irq >= 0) {
  		if (request_irq(omap_kp->irq, omap_kp_interrupt, 0,
  				"omap-keypad", omap_kp) < 0)
  			goto err4;
  	}
  	omap_writew(0, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  
  	return 0;
  
  err4:
  	input_unregister_device(omap_kp->input);
  	input_dev = NULL;
  err3:
  	device_remove_file(&pdev->dev, &dev_attr_enable);
  err2:
  	for (i = row_idx - 1; i >= 0; i--)
  		gpio_free(row_gpios[i]);
  	for (i = col_idx - 1; i >= 0; i--)
  		gpio_free(col_gpios[i]);
  
  	kfree(omap_kp);
  	input_free_device(input_dev);
  
  	return -EINVAL;
  }
  
  static int omap_kp_remove(struct platform_device *pdev)
  {
  	struct omap_kp *omap_kp = platform_get_drvdata(pdev);
  
  	/* disable keypad interrupt handling */
  	tasklet_disable(&kp_tasklet);
  	omap_writew(1, OMAP1_MPUIO_BASE + OMAP_MPUIO_KBD_MASKIT);
  	free_irq(omap_kp->irq, omap_kp);
  
  	del_timer_sync(&omap_kp->timer);
  	tasklet_kill(&kp_tasklet);
  
  	/* unregister everything */
  	input_unregister_device(omap_kp->input);
  
  	kfree(omap_kp);
  
  	return 0;
  }
  
  static struct platform_driver omap_kp_driver = {
  	.probe		= omap_kp_probe,
  	.remove		= omap_kp_remove,
  	.suspend	= omap_kp_suspend,
  	.resume		= omap_kp_resume,
  	.driver		= {
  		.name	= "omap-keypad",
  		.owner	= THIS_MODULE,
  	},
  };
  module_platform_driver(omap_kp_driver);
  
  MODULE_AUTHOR("Timo Teräs");
  MODULE_DESCRIPTION("OMAP Keypad Driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:omap-keypad");