/*
   * Copyright (c) 2008-2009 Nuvoton technology corporation.
   *
   * Wan ZongShun <mcuos.com@gmail.com>
   *
   * 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;version 2 of the License.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/interrupt.h>
  #include <linux/input.h>
  #include <linux/device.h>
  #include <linux/platform_device.h>
  #include <linux/clk.h>
  #include <linux/err.h>
  #include <linux/io.h>
  #include <linux/slab.h>
  
  #include <linux/platform_data/keypad-w90p910.h>
  
  /* Keypad Interface Control Registers */
  #define KPI_CONF		0x00
  #define KPI_3KCONF		0x04
  #define KPI_LPCONF		0x08
  #define KPI_STATUS		0x0C
  
  #define IS1KEY			(0x01 << 16)
  #define INTTR			(0x01 << 21)
  #define KEY0R			(0x0f << 3)
  #define KEY0C			0x07
  #define DEBOUNCE_BIT		0x08
  #define KSIZE0			(0x01 << 16)
  #define KSIZE1			(0x01 << 17)
  #define KPSEL			(0x01 << 19)
  #define ENKP			(0x01 << 18)
  
  #define KGET_RAW(n)		(((n) & KEY0R) >> 3)
  #define KGET_COLUMN(n)		((n) & KEY0C)
  
  #define W90P910_NUM_ROWS	8
  #define W90P910_NUM_COLS	8
  #define W90P910_ROW_SHIFT	3
  
  struct w90p910_keypad {
  	const struct w90p910_keypad_platform_data *pdata;
  	struct clk *clk;
  	struct input_dev *input_dev;
  	void __iomem *mmio_base;
  	int irq;
  	unsigned short keymap[W90P910_NUM_ROWS * W90P910_NUM_COLS];
  };
  
  static void w90p910_keypad_scan_matrix(struct w90p910_keypad *keypad,
  							unsigned int status)
  {
  	struct input_dev *input_dev = keypad->input_dev;
  	unsigned int row = KGET_RAW(status);
  	unsigned int col = KGET_COLUMN(status);
  	unsigned int code = MATRIX_SCAN_CODE(row, col, W90P910_ROW_SHIFT);
  	unsigned int key = keypad->keymap[code];
  
  	input_event(input_dev, EV_MSC, MSC_SCAN, code);
  	input_report_key(input_dev, key, 1);
  	input_sync(input_dev);
  
  	input_event(input_dev, EV_MSC, MSC_SCAN, code);
  	input_report_key(input_dev, key, 0);
  	input_sync(input_dev);
  }
  
  static irqreturn_t w90p910_keypad_irq_handler(int irq, void *dev_id)
  {
  	struct w90p910_keypad *keypad = dev_id;
  	unsigned int  kstatus, val;
  
  	kstatus = __raw_readl(keypad->mmio_base + KPI_STATUS);
  
  	val = INTTR | IS1KEY;
  
  	if (kstatus & val)
  		w90p910_keypad_scan_matrix(keypad, kstatus);
  
  	return IRQ_HANDLED;
  }
  
  static int w90p910_keypad_open(struct input_dev *dev)
  {
  	struct w90p910_keypad *keypad = input_get_drvdata(dev);
  	const struct w90p910_keypad_platform_data *pdata = keypad->pdata;
  	unsigned int val, config;
  
  	/* Enable unit clock */
  	clk_enable(keypad->clk);
  
  	val = __raw_readl(keypad->mmio_base + KPI_CONF);
  	val |= (KPSEL | ENKP);
  	val &= ~(KSIZE0 | KSIZE1);
  
  	config = pdata->prescale | (pdata->debounce << DEBOUNCE_BIT);
  
  	val |= config;
  
  	__raw_writel(val, keypad->mmio_base + KPI_CONF);
  
  	return 0;
  }
  
  static void w90p910_keypad_close(struct input_dev *dev)
  {
  	struct w90p910_keypad *keypad = input_get_drvdata(dev);
  
  	/* Disable clock unit */
  	clk_disable(keypad->clk);
  }
  
  static int w90p910_keypad_probe(struct platform_device *pdev)
  {
  	const struct w90p910_keypad_platform_data *pdata =
  						dev_get_platdata(&pdev->dev);
  	const struct matrix_keymap_data *keymap_data;
  	struct w90p910_keypad *keypad;
  	struct input_dev *input_dev;
  	struct resource *res;
  	int irq;
  	int error;
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "no platform data defined
  ");
  		return -EINVAL;
  	}
  
  	keymap_data = pdata->keymap_data;
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		dev_err(&pdev->dev, "failed to get keypad irq
  ");
  		return -ENXIO;
  	}
  
  	keypad = kzalloc(sizeof(struct w90p910_keypad), GFP_KERNEL);
  	input_dev = input_allocate_device();
  	if (!keypad || !input_dev) {
  		dev_err(&pdev->dev, "failed to allocate driver data
  ");
  		error = -ENOMEM;
  		goto failed_free;
  	}
  
  	keypad->pdata = pdata;
  	keypad->input_dev = input_dev;
  	keypad->irq = irq;
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (res == NULL) {
  		dev_err(&pdev->dev, "failed to get I/O memory
  ");
  		error = -ENXIO;
  		goto failed_free;
  	}
  
  	res = request_mem_region(res->start, resource_size(res), pdev->name);
  	if (res == NULL) {
  		dev_err(&pdev->dev, "failed to request I/O memory
  ");
  		error = -EBUSY;
  		goto failed_free;
  	}
  
  	keypad->mmio_base = ioremap(res->start, resource_size(res));
  	if (keypad->mmio_base == NULL) {
  		dev_err(&pdev->dev, "failed to remap I/O memory
  ");
  		error = -ENXIO;
  		goto failed_free_res;
  	}
  
  	keypad->clk = clk_get(&pdev->dev, NULL);
  	if (IS_ERR(keypad->clk)) {
  		dev_err(&pdev->dev, "failed to get keypad clock
  ");
  		error = PTR_ERR(keypad->clk);
  		goto failed_free_io;
  	}
  
  	/* set multi-function pin for w90p910 kpi. */
  	mfp_set_groupi(&pdev->dev);
  
  	input_dev->name = pdev->name;
  	input_dev->id.bustype = BUS_HOST;
  	input_dev->open = w90p910_keypad_open;
  	input_dev->close = w90p910_keypad_close;
  	input_dev->dev.parent = &pdev->dev;
  
  	error = matrix_keypad_build_keymap(keymap_data, NULL,
  					   W90P910_NUM_ROWS, W90P910_NUM_COLS,
  					   keypad->keymap, input_dev);
  	if (error) {
  		dev_err(&pdev->dev, "failed to build keymap
  ");
  		goto failed_put_clk;
  	}
  
  	error = request_irq(keypad->irq, w90p910_keypad_irq_handler,
  			    0, pdev->name, keypad);
  	if (error) {
  		dev_err(&pdev->dev, "failed to request IRQ
  ");
  		goto failed_put_clk;
  	}
  
  	__set_bit(EV_REP, input_dev->evbit);
  	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
  	input_set_drvdata(input_dev, keypad);
  
  	/* Register the input device */
  	error = input_register_device(input_dev);
  	if (error) {
  		dev_err(&pdev->dev, "failed to register input device
  ");
  		goto failed_free_irq;
  	}
  
  	platform_set_drvdata(pdev, keypad);
  	return 0;
  
  failed_free_irq:
  	free_irq(irq, keypad);
  failed_put_clk:
  	clk_put(keypad->clk);
  failed_free_io:
  	iounmap(keypad->mmio_base);
  failed_free_res:
  	release_mem_region(res->start, resource_size(res));
  failed_free:
  	input_free_device(input_dev);
  	kfree(keypad);
  	return error;
  }
  
  static int w90p910_keypad_remove(struct platform_device *pdev)
  {
  	struct w90p910_keypad *keypad = platform_get_drvdata(pdev);
  	struct resource *res;
  
  	free_irq(keypad->irq, keypad);
  
  	clk_put(keypad->clk);
  
  	input_unregister_device(keypad->input_dev);
  
  	iounmap(keypad->mmio_base);
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	release_mem_region(res->start, resource_size(res));
  
  	kfree(keypad);
  
  	return 0;
  }
  
  static struct platform_driver w90p910_keypad_driver = {
  	.probe		= w90p910_keypad_probe,
  	.remove		= w90p910_keypad_remove,
  	.driver		= {
  		.name	= "nuc900-kpi",
  	},
  };
  module_platform_driver(w90p910_keypad_driver);
  
  MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
  MODULE_DESCRIPTION("w90p910 keypad driver");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:nuc900-keypad");