text: /*
   * Copyright (C) ST-Ericsson SA 2010
   *
   * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
   * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
   *
   * License terms:GNU General Public License (GPL) version 2
   *
   * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
   * the Nomadik 8815 and Ux500 platforms.
   */
  
  #include <linux/platform_device.h>
  #include <linux/interrupt.h>
  #include <linux/spinlock.h>
  #include <linux/io.h>
  #include <linux/delay.h>
  #include <linux/input.h>
  #include <linux/slab.h>
  #include <linux/clk.h>
  #include <linux/module.h>
  
  #include <linux/platform_data/keypad-nomadik-ske.h>
  
  /* SKE_CR bits */
  #define SKE_KPMLT	(0x1 << 6)
  #define SKE_KPCN	(0x7 << 3)
  #define SKE_KPASEN	(0x1 << 2)
  #define SKE_KPASON	(0x1 << 7)
  
  /* SKE_IMSC bits */
  #define SKE_KPIMA	(0x1 << 2)
  
  /* SKE_ICR bits */
  #define SKE_KPICS	(0x1 << 3)
  #define SKE_KPICA	(0x1 << 2)
  
  /* SKE_RIS bits */
  #define SKE_KPRISA	(0x1 << 2)
  
  #define SKE_KEYPAD_ROW_SHIFT	3
  #define SKE_KPD_NUM_ROWS	8
  #define SKE_KPD_NUM_COLS	8
  
  /* keypad auto scan registers */
  #define SKE_ASR0	0x20
  #define SKE_ASR1	0x24
  #define SKE_ASR2	0x28
  #define SKE_ASR3	0x2C
  
  #define SKE_NUM_ASRX_REGISTERS	(4)
  #define	KEY_PRESSED_DELAY	10
  
  /**
   * struct ske_keypad  - data structure used by keypad driver
   * @irq:	irq no
   * @reg_base:	ske regsiters base address
   * @input:	pointer to input device object
   * @board:	keypad platform device
   * @keymap:	matrix scan code table for keycodes
   * @clk:	clock structure pointer
   */
  struct ske_keypad {
  	int irq;
  	void __iomem *reg_base;
  	struct input_dev *input;
  	const struct ske_keypad_platform_data *board;
  	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
  	struct clk *clk;
  	struct clk *pclk;
  	spinlock_t ske_keypad_lock;
  };
  
  static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
  		u8 mask, u8 data)
  {
  	u32 ret;
  
  	spin_lock(&keypad->ske_keypad_lock);
  
  	ret = readl(keypad->reg_base + addr);
  	ret &= ~mask;
  	ret |= data;
  	writel(ret, keypad->reg_base + addr);
  
  	spin_unlock(&keypad->ske_keypad_lock);
  }
  
  /*
   * ske_keypad_chip_init: init keypad controller configuration
   *
   * Enable Multi key press detection, auto scan mode
   */
  static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
  {
  	u32 value;
  	int timeout = keypad->board->debounce_ms;
  
  	/* check SKE_RIS to be 0 */
  	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
  		cpu_relax();
  
  	if (!timeout)
  		return -EINVAL;
  
  	/*
  	 * set debounce value
  	 * keypad dbounce is configured in DBCR[15:8]
  	 * dbounce value in steps of 32/32.768 ms
  	 */
  	spin_lock(&keypad->ske_keypad_lock);
  	value = readl(keypad->reg_base + SKE_DBCR);
  	value = value & 0xff;
  	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
  	writel(value, keypad->reg_base + SKE_DBCR);
  	spin_unlock(&keypad->ske_keypad_lock);
  
  	/* enable multi key detection */
  	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
  
  	/*
  	 * set up the number of columns
  	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
  	 */
  	value = (keypad->board->kcol - 1) << 3;
  	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
  
  	/* clear keypad interrupt for auto(and pending SW) scans */
  	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
  
  	/* un-mask keypad interrupts */
  	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
  
  	/* enable automatic scan */
  	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
  
  	return 0;
  }
  
  static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
  {
  	int row = 0, code, pos;
  	struct input_dev *input = keypad->input;
  	u32 ske_ris;
  	int key_pressed;
  	int num_of_rows;
  
  	/* find out the row */
  	num_of_rows = hweight8(status);
  	do {
  		pos = __ffs(status);
  		row = pos;
  		status &= ~(1 << pos);
  
  		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
  		ske_ris = readl(keypad->reg_base + SKE_RIS);
  		key_pressed = ske_ris & SKE_KPRISA;
  
  		input_event(input, EV_MSC, MSC_SCAN, code);
  		input_report_key(input, keypad->keymap[code], key_pressed);
  		input_sync(input);
  		num_of_rows--;
  	} while (num_of_rows);
  }
  
  static void ske_keypad_read_data(struct ske_keypad *keypad)
  {
  	u8 status;
  	int col = 0;
  	int ske_asr, i;
  
  	/*
  	 * Read the auto scan registers
  	 *
  	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
  	 * lower byte contains row value for column 2*x,
  	 * upper byte contains row value for column 2*x + 1
  	 */
  	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
  		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
  		if (!ske_asr)
  			continue;
  
  		/* now that ASRx is zero, find out the coloumn x and row y */
  		status = ske_asr & 0xff;
  		if (status) {
  			col = i * 2;
  			ske_keypad_report(keypad, status, col);
  		}
  		status = (ske_asr & 0xff00) >> 8;
  		if (status) {
  			col = (i * 2) + 1;
  			ske_keypad_report(keypad, status, col);
  		}
  	}
  }
  
  static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
  {
  	struct ske_keypad *keypad = dev_id;
  	int timeout = keypad->board->debounce_ms;
  
  	/* disable auto scan interrupt; mask the interrupt generated */
  	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
  	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
  
  	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
  		cpu_relax();
  
  	/* SKEx registers are stable and can be read */
  	ske_keypad_read_data(keypad);
  
  	/* wait until raw interrupt is clear */
  	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
  		msleep(KEY_PRESSED_DELAY);
  
  	/* enable auto scan interrupts */
  	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
  
  	return IRQ_HANDLED;
  }
  
  static int __init ske_keypad_probe(struct platform_device *pdev)
  {
  	const struct ske_keypad_platform_data *plat = pdev->dev.platform_data;
  	struct ske_keypad *keypad;
  	struct input_dev *input;
  	struct resource *res;
  	int irq;
  	int error;
  
  	if (!plat) {
  		dev_err(&pdev->dev, "invalid keypad platform data\n");
  		return -EINVAL;
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		dev_err(&pdev->dev, "failed to get keypad irq\n");
  		return -EINVAL;
  	}
  
  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!res) {
  		dev_err(&pdev->dev, "missing platform resources\n");
  		return -EINVAL;
  	}
  
  	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
  	input = input_allocate_device();
  	if (!keypad || !input) {
  		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
  		error = -ENOMEM;
  		goto err_free_mem;
  	}
  
  	keypad->irq = irq;
  	keypad->board = plat;
  	keypad->input = input;
  	spin_lock_init(&keypad->ske_keypad_lock);
  
  	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
  		dev_err(&pdev->dev, "failed to request I/O memory\n");
  		error = -EBUSY;
  		goto err_free_mem;
  	}
  
  	keypad->reg_base = ioremap(res->start, resource_size(res));
  	if (!keypad->reg_base) {
  		dev_err(&pdev->dev, "failed to remap I/O memory\n");
  		error = -ENXIO;
  		goto err_free_mem_region;
  	}
  
  	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
  	if (IS_ERR(keypad->pclk)) {
  		dev_err(&pdev->dev, "failed to get pclk\n");
  		error = PTR_ERR(keypad->pclk);
  		goto err_iounmap;
  	}
  
  	keypad->clk = clk_get(&pdev->dev, NULL);
  	if (IS_ERR(keypad->clk)) {
  		dev_err(&pdev->dev, "failed to get clk\n");
  		error = PTR_ERR(keypad->clk);
  		goto err_pclk;
  	}
  
  	input->id.bustype = BUS_HOST;
  	input->name = "ux500-ske-keypad";
  	input->dev.parent = &pdev->dev;
  
  	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
  					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
  					   keypad->keymap, input);
  	if (error) {
  		dev_err(&pdev->dev, "Failed to build keymap\n");
  		goto err_clk;
  	}
  
  	input_set_capability(input, EV_MSC, MSC_SCAN);
  	if (!plat->no_autorepeat)
  		__set_bit(EV_REP, input->evbit);
  
  	error = clk_prepare_enable(keypad->pclk);
  	if (error) {
  		dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
  		goto err_clk;
  	}
  
  	error = clk_prepare_enable(keypad->clk);
  	if (error) {
  		dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
  		goto err_pclk_disable;
  	}
  
  
  	/* go through board initialization helpers */
  	if (keypad->board->init)
  		keypad->board->init();
  
  	error = ske_keypad_chip_init(keypad);
  	if (error) {
  		dev_err(&pdev->dev, "unable to init keypad hardware\n");
  		goto err_clk_disable;
  	}
  
  	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
  				     IRQF_ONESHOT, "ske-keypad", keypad);
  	if (error) {
  		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
  		goto err_clk_disable;
  	}
  
  	error = input_register_device(input);
  	if (error) {
  		dev_err(&pdev->dev,
  				"unable to register input device: %d\n", error);
  		goto err_free_irq;
  	}
  
  	if (plat->wakeup_enable)
  		device_init_wakeup(&pdev->dev, true);
  
  	platform_set_drvdata(pdev, keypad);
  
  	return 0;
  
  err_free_irq:
  	free_irq(keypad->irq, keypad);
  err_clk_disable:
  	clk_disable_unprepare(keypad->clk);
  err_pclk_disable:
  	clk_disable_unprepare(keypad->pclk);
  err_clk:
  	clk_put(keypad->clk);
  err_pclk:
  	clk_put(keypad->pclk);
  err_iounmap:
  	iounmap(keypad->reg_base);
  err_free_mem_region:
  	release_mem_region(res->start, resource_size(res));
  err_free_mem:
  	input_free_device(input);
  	kfree(keypad);
  	return error;
  }
  
  static int ske_keypad_remove(struct platform_device *pdev)
  {
  	struct ske_keypad *keypad = platform_get_drvdata(pdev);
  	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  
  	free_irq(keypad->irq, keypad);
  
  	input_unregister_device(keypad->input);
  
  	clk_disable_unprepare(keypad->clk);
  	clk_put(keypad->clk);
  
  	if (keypad->board->exit)
  		keypad->board->exit();
  
  	iounmap(keypad->reg_base);
  	release_mem_region(res->start, resource_size(res));
  	kfree(keypad);
  
  	return 0;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int ske_keypad_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct ske_keypad *keypad = platform_get_drvdata(pdev);
  	int irq = platform_get_irq(pdev, 0);
  
  	if (device_may_wakeup(dev))
  		enable_irq_wake(irq);
  	else
  		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
  
  	return 0;
  }
  
  static int ske_keypad_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct ske_keypad *keypad = platform_get_drvdata(pdev);
  	int irq = platform_get_irq(pdev, 0);
  
  	if (device_may_wakeup(dev))
  		disable_irq_wake(irq);
  	else
  		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
  			 ske_keypad_suspend, ske_keypad_resume);
  
  static struct platform_driver ske_keypad_driver = {
  	.driver = {
  		.name = "nmk-ske-keypad",
  		.owner  = THIS_MODULE,
  		.pm = &ske_keypad_dev_pm_ops,
  	},
  	.remove = ske_keypad_remove,
  };
  
  module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
  
  MODULE_LICENSE("GPL v2");
  MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
  MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
  MODULE_ALIAS("platform:nomadik-ske-keypad");
  