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Commit 69690bec authored by Roland Stigge's avatar Roland Stigge Committed by Dmitry Torokhov
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Input: add support for key scan interface of the LPC32xx SoC 



This is a driver for the key scan interface of the LPC32xx SoC

Signed-off-by: default avatarRoland Stigge <stigge@antcom.de>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 13987435

Documentation/devicetree/bindings/input/lpc32xx-key.txt

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NXP LPC32xx Key Scan Interface



Required Properties:

- compatible: Should be "nxp,lpc3220-key"

- reg: Physical base address of the controller and length of memory mapped

  region.

- interrupts: The interrupt number to the cpu.

- keypad,num-rows: Number of rows and columns, e.g. 1: 1x1, 6: 6x6

- keypad,num-columns: Must be equal to keypad,num-rows since LPC32xx only

  supports square matrices

- nxp,debounce-delay-ms: Debounce delay in ms

- nxp,scan-delay-ms: Repeated scan period in ms

- linux,keymap: the key-code to be reported when the key is pressed

  and released, see also

  Documentation/devicetree/bindings/input/matrix-keymap.txt



Example:



	key@40050000 {

		compatible = "nxp,lpc3220-key";

		reg = <0x40050000 0x1000>;

		interrupts = <54 0>;

		keypad,num-rows = <1>;

		keypad,num-columns = <1>;

		nxp,debounce-delay-ms = <3>;

		nxp,scan-delay-ms = <34>;

		linux,keymap = <0x00000002>;

	};

drivers/input/keyboard/Kconfig

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@@ -332,6 +332,16 @@ config KEYBOARD_LOCOMO 
	  To compile this driver as a module, choose M here: the

	  To compile this driver as a module, choose M here: the

	  module will be called locomokbd.

	  module will be called locomokbd.





config KEYBOARD_LPC32XX

	tristate "LPC32XX matrix key scanner support"

	depends on ARCH_LPC32XX && OF

	help

	  Say Y here if you want to use NXP LPC32XX SoC key scanner interface,

	  connected to a key matrix.



	  To compile this driver as a module, choose M here: the

	  module will be called lpc32xx-keys.



config KEYBOARD_MAPLE

config KEYBOARD_MAPLE

	tristate "Maple bus keyboard"

	tristate "Maple bus keyboard"

	depends on SH_DREAMCAST && MAPLE

	depends on SH_DREAMCAST && MAPLE

drivers/input/keyboard/Makefile

+1 −0
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@@ -26,6 +26,7 @@ obj-$(CONFIG_KEYBOARD_LKKBD) += lkkbd.o 
obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o

obj-$(CONFIG_KEYBOARD_LM8323)		+= lm8323.o

obj-$(CONFIG_KEYBOARD_LM8333)		+= lm8333.o

obj-$(CONFIG_KEYBOARD_LM8333)		+= lm8333.o

obj-$(CONFIG_KEYBOARD_LOCOMO)		+= locomokbd.o

obj-$(CONFIG_KEYBOARD_LOCOMO)		+= locomokbd.o

obj-$(CONFIG_KEYBOARD_LPC32XX)		+= lpc32xx-keys.o

obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o

obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o

obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o

obj-$(CONFIG_KEYBOARD_MATRIX)		+= matrix_keypad.o

obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o

obj-$(CONFIG_KEYBOARD_MAX7359)		+= max7359_keypad.o

drivers/input/keyboard/lpc32xx-keys.c

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/*

 * NXP LPC32xx SoC Key Scan Interface

 *

 * Authors:

 *    Kevin Wells <kevin.wells@nxp.com>

 *    Roland Stigge <stigge@antcom.de>

 *

 * Copyright (C) 2010 NXP Semiconductors

 * Copyright (C) 2012 Roland Stigge

 *

 * 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.

 *

 *

 * This controller supports square key matrices from 1x1 up to 8x8

 */



#include <linux/module.h>

#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/irq.h>

#include <linux/pm.h>

#include <linux/platform_device.h>

#include <linux/input.h>

#include <linux/clk.h>

#include <linux/io.h>

#include <linux/of.h>

#include <linux/input/matrix_keypad.h>



#define DRV_NAME				"lpc32xx_keys"



/*

 * Key scanner register offsets

 */

#define LPC32XX_KS_DEB(x)			((x) + 0x00)

#define LPC32XX_KS_STATE_COND(x)		((x) + 0x04)

#define LPC32XX_KS_IRQ(x)			((x) + 0x08)

#define LPC32XX_KS_SCAN_CTL(x)			((x) + 0x0C)

#define LPC32XX_KS_FAST_TST(x)			((x) + 0x10)

#define LPC32XX_KS_MATRIX_DIM(x)		((x) + 0x14) /* 1..8 */

#define LPC32XX_KS_DATA(x, y)			((x) + 0x40 + ((y) << 2))



#define LPC32XX_KSCAN_DEB_NUM_DEB_PASS(n)	((n) & 0xFF)



#define LPC32XX_KSCAN_SCOND_IN_IDLE		0x0

#define LPC32XX_KSCAN_SCOND_IN_SCANONCE		0x1

#define LPC32XX_KSCAN_SCOND_IN_IRQGEN		0x2

#define LPC32XX_KSCAN_SCOND_IN_SCAN_MATRIX	0x3



#define LPC32XX_KSCAN_IRQ_PENDING_CLR		0x1



#define LPC32XX_KSCAN_SCTRL_SCAN_DELAY(n)	((n) & 0xFF)



#define LPC32XX_KSCAN_FTST_FORCESCANONCE	0x1

#define LPC32XX_KSCAN_FTST_USE32K_CLK		0x2



#define LPC32XX_KSCAN_MSEL_SELECT(n)		((n) & 0xF)



struct lpc32xx_kscan_drv {

	struct input_dev *input;

	struct clk *clk;

	struct resource *iores;

	void __iomem *kscan_base;

	unsigned int irq;



	u32 matrix_sz;		/* Size of matrix in XxY, ie. 3 = 3x3 */

	u32 deb_clks;		/* Debounce clocks (based on 32KHz clock) */

	u32 scan_delay;		/* Scan delay (based on 32KHz clock) */



	unsigned short *keymap;	/* Pointer to key map for the scan matrix */

	unsigned int row_shift;



	u8 lastkeystates[8];

};



static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)

{

	struct input_dev *input = kscandat->input;

	unsigned row, changed, scancode, keycode;

	u8 key;



	key = readl(LPC32XX_KS_DATA(kscandat->kscan_base, col));

	changed = key ^ kscandat->lastkeystates[col];

	kscandat->lastkeystates[col] = key;



	for (row = 0; changed; row++, changed >>= 1) {

		if (changed & 1) {

			/* Key state changed, signal an event */

			scancode = MATRIX_SCAN_CODE(row, col,

						    kscandat->row_shift);

			keycode = kscandat->keymap[scancode];

			input_event(input, EV_MSC, MSC_SCAN, scancode);

			input_report_key(input, keycode, key & (1 << row));

		}

	}

}



static irqreturn_t lpc32xx_kscan_irq(int irq, void *dev_id)

{

	struct lpc32xx_kscan_drv *kscandat = dev_id;

	int i;



	for (i = 0; i < kscandat->matrix_sz; i++)

		lpc32xx_mod_states(kscandat, i);



	writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));



	input_sync(kscandat->input);



	return IRQ_HANDLED;

}



static int lpc32xx_kscan_open(struct input_dev *dev)

{

	struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);

	int error;



	error = clk_prepare_enable(kscandat->clk);

	if (error)

		return error;



	writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));



	return 0;

}



static void lpc32xx_kscan_close(struct input_dev *dev)

{

	struct lpc32xx_kscan_drv *kscandat = input_get_drvdata(dev);



	writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));

	clk_disable_unprepare(kscandat->clk);

}



static int __devinit lpc32xx_parse_dt(struct device *dev,

				      struct lpc32xx_kscan_drv *kscandat)

{

	struct device_node *np = dev->of_node;

	u32 rows = 0, columns = 0;



	of_property_read_u32(np, "keypad,num-rows", &rows);

	of_property_read_u32(np, "keypad,num-columns", &columns);

	if (!rows || rows != columns) {

		dev_err(dev,

			"rows and columns must be specified and be equal!\n");

		return -EINVAL;

	}



	kscandat->matrix_sz = rows;

	kscandat->row_shift = get_count_order(columns);



	of_property_read_u32(np, "nxp,debounce-delay-ms", &kscandat->deb_clks);

	of_property_read_u32(np, "nxp,scan-delay-ms", &kscandat->scan_delay);

	if (!kscandat->deb_clks || !kscandat->scan_delay) {

		dev_err(dev, "debounce or scan delay not specified\n");

		return -EINVAL;

	}



	return 0;

}



static int __devinit lpc32xx_kscan_probe(struct platform_device *pdev)

{

	struct lpc32xx_kscan_drv *kscandat;

	struct input_dev *input;

	struct resource *res;

	size_t keymap_size;

	int error;

	int irq;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {

		dev_err(&pdev->dev, "failed to get platform I/O memory\n");

		return -EINVAL;

	}



	irq = platform_get_irq(pdev, 0);

	if (irq < 0 || irq >= NR_IRQS) {

		dev_err(&pdev->dev, "failed to get platform irq\n");

		return -EINVAL;

	}



	kscandat = kzalloc(sizeof(struct lpc32xx_kscan_drv), GFP_KERNEL);

	if (!kscandat) {

		dev_err(&pdev->dev, "failed to allocate memory\n");

		return -ENOMEM;

	}



	error = lpc32xx_parse_dt(&pdev->dev, kscandat);

	if (error) {

		dev_err(&pdev->dev, "failed to parse device tree\n");

		goto err_free_mem;

	}



	keymap_size = sizeof(kscandat->keymap[0]) *

				(kscandat->matrix_sz << kscandat->row_shift);

	kscandat->keymap = kzalloc(keymap_size, GFP_KERNEL);

	if (!kscandat->keymap) {

		dev_err(&pdev->dev, "could not allocate memory for keymap\n");

		error = -ENOMEM;

		goto err_free_mem;

	}



	kscandat->input = input = input_allocate_device();

	if (!input) {

		dev_err(&pdev->dev, "failed to allocate input device\n");

		error = -ENOMEM;

		goto err_free_keymap;

	}



	/* Setup key input */

	input->name		= pdev->name;

	input->phys		= "lpc32xx/input0";

	input->id.vendor	= 0x0001;

	input->id.product	= 0x0001;

	input->id.version	= 0x0100;

	input->open		= lpc32xx_kscan_open;

	input->close		= lpc32xx_kscan_close;

	input->dev.parent	= &pdev->dev;



	input_set_capability(input, EV_MSC, MSC_SCAN);



	error = matrix_keypad_build_keymap(NULL, NULL,

					   kscandat->matrix_sz,

					   kscandat->matrix_sz,

					   kscandat->keymap, kscandat->input);

	if (error) {

		dev_err(&pdev->dev, "failed to build keymap\n");

		goto err_free_input;

	}



	input_set_drvdata(kscandat->input, kscandat);



	kscandat->iores = request_mem_region(res->start, resource_size(res),

					     pdev->name);

	if (!kscandat->iores) {

		dev_err(&pdev->dev, "failed to request I/O memory\n");

		error = -EBUSY;

		goto err_free_input;

	}



	kscandat->kscan_base = ioremap(kscandat->iores->start,

				       resource_size(kscandat->iores));

	if (!kscandat->kscan_base) {

		dev_err(&pdev->dev, "failed to remap I/O memory\n");

		error = -EBUSY;

		goto err_release_memregion;

	}



	/* Get the key scanner clock */

	kscandat->clk = clk_get(&pdev->dev, NULL);

	if (IS_ERR(kscandat->clk)) {

		dev_err(&pdev->dev, "failed to get clock\n");

		error = PTR_ERR(kscandat->clk);

		goto err_unmap;

	}



	/* Configure the key scanner */

	error = clk_prepare_enable(kscandat->clk);

	if (error)

		goto err_clk_put;



	writel(kscandat->deb_clks, LPC32XX_KS_DEB(kscandat->kscan_base));

	writel(kscandat->scan_delay, LPC32XX_KS_SCAN_CTL(kscandat->kscan_base));

	writel(LPC32XX_KSCAN_FTST_USE32K_CLK,

	       LPC32XX_KS_FAST_TST(kscandat->kscan_base));

	writel(kscandat->matrix_sz,

	       LPC32XX_KS_MATRIX_DIM(kscandat->kscan_base));

	writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));

	clk_disable_unprepare(kscandat->clk);



	error = request_irq(irq, lpc32xx_kscan_irq, 0, pdev->name, kscandat);

	if (error) {

		dev_err(&pdev->dev, "failed to request irq\n");

		goto err_clk_put;

	}



	error = input_register_device(kscandat->input);

	if (error) {

		dev_err(&pdev->dev, "failed to register input device\n");

		goto err_free_irq;

	}



	platform_set_drvdata(pdev, kscandat);

	return 0;



err_free_irq:

	free_irq(irq, kscandat);

err_clk_put:

	clk_put(kscandat->clk);

err_unmap:

	iounmap(kscandat->kscan_base);

err_release_memregion:

	release_mem_region(kscandat->iores->start,

			   resource_size(kscandat->iores));

err_free_input:

	input_free_device(kscandat->input);

err_free_keymap:

	kfree(kscandat->keymap);

err_free_mem:

	kfree(kscandat);



	return error;

}



static int __devexit lpc32xx_kscan_remove(struct platform_device *pdev)

{

	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);



	free_irq(platform_get_irq(pdev, 0), kscandat);

	clk_put(kscandat->clk);

	iounmap(kscandat->kscan_base);

	release_mem_region(kscandat->iores->start,

			   resource_size(kscandat->iores));

	input_unregister_device(kscandat->input);

	kfree(kscandat->keymap);

	kfree(kscandat);



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int lpc32xx_kscan_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);

	struct input_dev *input = kscandat->input;



	mutex_lock(&input->mutex);



	if (input->users) {

		/* Clear IRQ and disable clock */

		writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));

		clk_disable_unprepare(kscandat->clk);

	}



	mutex_unlock(&input->mutex);

	return 0;

}



static int lpc32xx_kscan_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);

	struct input_dev *input = kscandat->input;

	int retval = 0;



	mutex_lock(&input->mutex);



	if (input->users) {

		/* Enable clock and clear IRQ */

		retval = clk_prepare_enable(kscandat->clk);

		if (retval == 0)

			writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));

	}



	mutex_unlock(&input->mutex);

	return retval;

}

#endif



static SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,

			 lpc32xx_kscan_resume);



static const struct of_device_id lpc32xx_kscan_match[] = {

	{ .compatible = "nxp,lpc3220-key" },

	{},

};

MODULE_DEVICE_TABLE(of, lpc32xx_kscan_match);



static struct platform_driver lpc32xx_kscan_driver = {

	.probe		= lpc32xx_kscan_probe,

	.remove		= __devexit_p(lpc32xx_kscan_remove),

	.driver		= {

		.name	= DRV_NAME,

		.owner	= THIS_MODULE,

		.pm	= &lpc32xx_kscan_pm_ops,

		.of_match_table = of_match_ptr(lpc32xx_kscan_match),

	}

};



module_platform_driver(lpc32xx_kscan_driver);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");

MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");

MODULE_DESCRIPTION("Key scanner driver for LPC32XX devices");