[linux-2.6-block.git] / drivers / input / keyboard / nspire-keypad.c

/*
 *  Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
 *
 * 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/input/matrix_keypad.h>
#include <linux/platform_device.h>
#include <linux/interrupt.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/of.h>

#define KEYPAD_SCAN_MODE	0x00
#define KEYPAD_CNTL		0x04
#define KEYPAD_INT		0x08
#define KEYPAD_INTMSK		0x0C

#define KEYPAD_DATA		0x10
#define KEYPAD_GPIO		0x30

#define KEYPAD_UNKNOWN_INT	0x40
#define KEYPAD_UNKNOWN_INT_STS	0x44

#define KEYPAD_BITMASK_COLS	11
#define KEYPAD_BITMASK_ROWS	8

struct nspire_keypad {
	void __iomem *reg_base;
	u32 int_mask;

	struct input_dev *input;
	struct clk *clk;

	struct matrix_keymap_data *keymap;
	int row_shift;

	/* Maximum delay estimated assuming 33MHz APB */
	u32 scan_interval;	/* In microseconds (~2000us max) */
	u32 row_delay;		/* In microseconds (~500us max) */

	u16 state[KEYPAD_BITMASK_ROWS];

	bool active_low;
};

static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
{
	struct nspire_keypad *keypad = dev_id;
	struct input_dev *input = keypad->input;
	unsigned short *keymap = input->keycode;
	unsigned int code;
	int row, col;
	u32 int_sts;
	u16 state[8];
	u16 bits, changed;

	int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
	if (!int_sts)
		return IRQ_NONE;

	memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));

	for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
		bits = state[row];
		if (keypad->active_low)
			bits = ~bits;

		changed = bits ^ keypad->state[row];
		if (!changed)
			continue;

		keypad->state[row] = bits;

		for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
			if (!(changed & (1U << col)))
				continue;

			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
			input_event(input, EV_MSC, MSC_SCAN, code);
			input_report_key(input, keymap[code],
					 bits & (1U << col));
		}
	}

	input_sync(input);

	writel(0x3, keypad->reg_base + KEYPAD_INT);

	return IRQ_HANDLED;
}

static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
{
	unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;

	cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
	if (cycles_per_us == 0)
		cycles_per_us = 1;

	delay_cycles = cycles_per_us * keypad->scan_interval;
	WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
	delay_cycles &= 0xffff;

	row_delay_cycles = cycles_per_us * keypad->row_delay;
	WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
	row_delay_cycles &= 0x3fff;

	val |= 3 << 0; /* Set scan mode to 3 (continuous scan) */
	val |= row_delay_cycles << 2; /* Delay between scanning each row */
	val |= delay_cycles << 16; /* Delay between scans */
	writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);

	val = (KEYPAD_BITMASK_ROWS & 0xff) | (KEYPAD_BITMASK_COLS & 0xff)<<8;
	writel(val, keypad->reg_base + KEYPAD_CNTL);

	/* Enable interrupts */
	keypad->int_mask = 1 << 1;
	writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);

	/* Disable GPIO interrupts to prevent hanging on touchpad */
	/* Possibly used to detect touchpad events */
	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
	/* Acknowledge existing interrupts */
	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);

	return 0;
}

static int nspire_keypad_open(struct input_dev *input)
{
	struct nspire_keypad *keypad = input_get_drvdata(input);
	int error;

	error = clk_prepare_enable(keypad->clk);
	if (error)
		return error;

	error = nspire_keypad_chip_init(keypad);
	if (error) {
		clk_disable_unprepare(keypad->clk);
		return error;
	}

	return 0;
}

static void nspire_keypad_close(struct input_dev *input)
{
	struct nspire_keypad *keypad = input_get_drvdata(input);

	clk_disable_unprepare(keypad->clk);
}

static int nspire_keypad_probe(struct platform_device *pdev)
{
	const struct device_node *of_node = pdev->dev.of_node;
	struct nspire_keypad *keypad;
	struct input_dev *input;
	struct resource *res;
	int irq;
	int error;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "failed to get keypad irq\n");
		return -EINVAL;
	}

	keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
			      GFP_KERNEL);
	if (!keypad) {
		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
		return -ENOMEM;
	}

	keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);

	error = of_property_read_u32(of_node, "scan-interval",
				     &keypad->scan_interval);
	if (error) {
		dev_err(&pdev->dev, "failed to get scan-interval\n");
		return error;
	}

	error = of_property_read_u32(of_node, "row-delay",
				     &keypad->row_delay);
	if (error) {
		dev_err(&pdev->dev, "failed to get row-delay\n");
		return error;
	}

	keypad->active_low = of_property_read_bool(of_node, "active-low");

	keypad->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(keypad->clk)) {
		dev_err(&pdev->dev, "unable to get clock\n");
		return PTR_ERR(keypad->clk);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(keypad->reg_base))
		return PTR_ERR(keypad->reg_base);

	keypad->input = input = devm_input_allocate_device(&pdev->dev);
	if (!input) {
		dev_err(&pdev->dev, "failed to allocate input device\n");
		return -ENOMEM;
	}

	input_set_drvdata(input, keypad);

	input->id.bustype = BUS_HOST;
	input->name = "nspire-keypad";
	input->open = nspire_keypad_open;
	input->close = nspire_keypad_close;

	__set_bit(EV_KEY, input->evbit);
	__set_bit(EV_REP, input->evbit);
	input_set_capability(input, EV_MSC, MSC_SCAN);

	error = matrix_keypad_build_keymap(NULL, NULL,
					   KEYPAD_BITMASK_ROWS,
					   KEYPAD_BITMASK_COLS,
					   NULL, input);
	if (error) {
		dev_err(&pdev->dev, "building keymap failed\n");
		return error;
	}

	error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
				 "nspire_keypad", keypad);
	if (error) {
		dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
		return error;
	}

	error = input_register_device(input);
	if (error) {
		dev_err(&pdev->dev,
			"unable to register input device: %d\n", error);
		return error;
	}

	platform_set_drvdata(pdev, keypad);

	dev_dbg(&pdev->dev,
		"TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
		res, keypad->row_delay, keypad->scan_interval,
		keypad->active_low ? ", active_low" : "");

	return 0;
}

static const struct of_device_id nspire_keypad_dt_match[] = {
	{ .compatible = "ti,nspire-keypad" },
	{ },
};
MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);

static struct platform_driver nspire_keypad_driver = {
	.driver = {
		.name = "nspire-keypad",
		.of_match_table = nspire_keypad_dt_match,
	},
	.probe = nspire_keypad_probe,
};

module_platform_driver(nspire_keypad_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");
Commit	Line	Data
fc4f3146 DT	1	/*
	2	* Copyright (C) 2013 Daniel Tang <tangrs@tangrs.id.au>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2, as
	6	* published by the Free Software Foundation.
	7	*/
	8
	9	#include <linux/input/matrix_keypad.h>
	10	#include <linux/platform_device.h>
	11	#include <linux/interrupt.h>
	12	#include <linux/io.h>
	13	#include <linux/delay.h>
	14	#include <linux/input.h>
	15	#include <linux/slab.h>
	16	#include <linux/clk.h>
	17	#include <linux/module.h>
	18	#include <linux/of.h>
	19
	20	#define KEYPAD_SCAN_MODE 0x00
	21	#define KEYPAD_CNTL 0x04
	22	#define KEYPAD_INT 0x08
	23	#define KEYPAD_INTMSK 0x0C
	24
	25	#define KEYPAD_DATA 0x10
	26	#define KEYPAD_GPIO 0x30
	27
	28	#define KEYPAD_UNKNOWN_INT 0x40
	29	#define KEYPAD_UNKNOWN_INT_STS 0x44
	30
	31	#define KEYPAD_BITMASK_COLS 11
	32	#define KEYPAD_BITMASK_ROWS 8
	33
	34	struct nspire_keypad {
	35	void __iomem *reg_base;
	36	u32 int_mask;
	37
	38	struct input_dev *input;
	39	struct clk *clk;
	40
	41	struct matrix_keymap_data *keymap;
	42	int row_shift;
	43
	44	/* Maximum delay estimated assuming 33MHz APB */
	45	u32 scan_interval; /* In microseconds (~2000us max) */
	46	u32 row_delay; /* In microseconds (~500us max) */
	47
	48	u16 state[KEYPAD_BITMASK_ROWS];
	49
	50	bool active_low;
	51	};
	52
	53	static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
	54	{
	55	struct nspire_keypad *keypad = dev_id;
	56	struct input_dev *input = keypad->input;
	57	unsigned short *keymap = input->keycode;
	58	unsigned int code;
	59	int row, col;
	60	u32 int_sts;
	61	u16 state[8];
	62	u16 bits, changed;
	63
	64	int_sts = readl(keypad->reg_base + KEYPAD_INT) & keypad->int_mask;
65	if (!int_sts)
66	return IRQ_NONE;
67
68	memcpy_fromio(state, keypad->reg_base + KEYPAD_DATA, sizeof(state));
69
70	for (row = 0; row < KEYPAD_BITMASK_ROWS; row++) {
71	bits = state[row];
72	if (keypad->active_low)
73	bits = ~bits;
74
75	changed = bits ^ keypad->state[row];
76	if (!changed)
77	continue;
78
79	keypad->state[row] = bits;
80
81	for (col = 0; col < KEYPAD_BITMASK_COLS; col++) {
82	if (!(changed & (1U << col)))
83	continue;
84
85	code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
86	input_event(input, EV_MSC, MSC_SCAN, code);
87	input_report_key(input, keymap[code],
88	bits & (1U << col));
89	}
90	}
91
92	input_sync(input);
93
94	writel(0x3, keypad->reg_base + KEYPAD_INT);
95
96	return IRQ_HANDLED;
97	}
98
99	static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
100	{
101	unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
102
103	cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
104	if (cycles_per_us == 0)
105	cycles_per_us = 1;
106
107	delay_cycles = cycles_per_us * keypad->scan_interval;
108	WARN_ON(delay_cycles >= (1 << 16)); /* Overflow */
109	delay_cycles &= 0xffff;
110
111	row_delay_cycles = cycles_per_us * keypad->row_delay;
112	WARN_ON(row_delay_cycles >= (1 << 14)); /* Overflow */
113	row_delay_cycles &= 0x3fff;
114
115	val \|= 3 << 0; /* Set scan mode to 3 (continuous scan) */
116	val \|= row_delay_cycles << 2; /* Delay between scanning each row */
117	val \|= delay_cycles << 16; /* Delay between scans */
118	writel(val, keypad->reg_base + KEYPAD_SCAN_MODE);
119
120	val = (KEYPAD_BITMASK_ROWS & 0xff) \| (KEYPAD_BITMASK_COLS & 0xff)<<8;
121	writel(val, keypad->reg_base + KEYPAD_CNTL);
122
123	/* Enable interrupts */
124	keypad->int_mask = 1 << 1;
46146e7d	125	writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
fc4f3146 DT	126
	127	/* Disable GPIO interrupts to prevent hanging on touchpad */
	128	/* Possibly used to detect touchpad events */
	129	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
	130	/* Acknowledge existing interrupts */
	131	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
	132
	133	return 0;
	134	}
	135
	136	static int nspire_keypad_open(struct input_dev *input)
	137	{
	138	struct nspire_keypad *keypad = input_get_drvdata(input);
	139	int error;
	140
	141	error = clk_prepare_enable(keypad->clk);
	142	if (error)
	143	return error;
	144
	145	error = nspire_keypad_chip_init(keypad);
a4da4752 WY	146	if (error) {
a4da4752 WY	147	clk_disable_unprepare(keypad->clk);
fc4f3146	148	return error;
a4da4752	149	}
fc4f3146 DT	150
	151	return 0;
	152	}
	153
	154	static void nspire_keypad_close(struct input_dev *input)
	155	{
	156	struct nspire_keypad *keypad = input_get_drvdata(input);
	157
	158	clk_disable_unprepare(keypad->clk);
	159	}
	160
	161	static int nspire_keypad_probe(struct platform_device *pdev)
	162	{
	163	const struct device_node *of_node = pdev->dev.of_node;
	164	struct nspire_keypad *keypad;
	165	struct input_dev *input;
	166	struct resource *res;
	167	int irq;
	168	int error;
	169
	170	irq = platform_get_irq(pdev, 0);
	171	if (irq < 0) {
	172	dev_err(&pdev->dev, "failed to get keypad irq\n");
	173	return -EINVAL;
	174	}
	175
fc4f3146 DT	176	keypad = devm_kzalloc(&pdev->dev, sizeof(struct nspire_keypad),
	177	GFP_KERNEL);
	178	if (!keypad) {
	179	dev_err(&pdev->dev, "failed to allocate keypad memory\n");
	180	return -ENOMEM;
	181	}
	182
	183	keypad->row_shift = get_count_order(KEYPAD_BITMASK_COLS);
	184
	185	error = of_property_read_u32(of_node, "scan-interval",
	186	&keypad->scan_interval);
	187	if (error) {
	188	dev_err(&pdev->dev, "failed to get scan-interval\n");
	189	return error;
	190	}
	191
	192	error = of_property_read_u32(of_node, "row-delay",
	193	&keypad->row_delay);
	194	if (error) {
	195	dev_err(&pdev->dev, "failed to get row-delay\n");
	196	return error;
	197	}
	198
	199	keypad->active_low = of_property_read_bool(of_node, "active-low");
	200
	201	keypad->clk = devm_clk_get(&pdev->dev, NULL);
	202	if (IS_ERR(keypad->clk)) {
	203	dev_err(&pdev->dev, "unable to get clock\n");
	204	return PTR_ERR(keypad->clk);
	205	}
	206
ef0aca7f	207	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
fc4f3146	208	keypad->reg_base = devm_ioremap_resource(&pdev->dev, res);
20c3da9f	209	if (IS_ERR(keypad->reg_base))
fc4f3146	210	return PTR_ERR(keypad->reg_base);
fc4f3146 DT	211
	212	keypad->input = input = devm_input_allocate_device(&pdev->dev);
	213	if (!input) {
	214	dev_err(&pdev->dev, "failed to allocate input device\n");
	215	return -ENOMEM;
	216	}
	217
	218	input_set_drvdata(input, keypad);
	219
	220	input->id.bustype = BUS_HOST;
	221	input->name = "nspire-keypad";
	222	input->open = nspire_keypad_open;
	223	input->close = nspire_keypad_close;
	224
	225	__set_bit(EV_KEY, input->evbit);
	226	__set_bit(EV_REP, input->evbit);
	227	input_set_capability(input, EV_MSC, MSC_SCAN);
	228
	229	error = matrix_keypad_build_keymap(NULL, NULL,
	230	KEYPAD_BITMASK_ROWS,
	231	KEYPAD_BITMASK_COLS,
	232	NULL, input);
	233	if (error) {
	234	dev_err(&pdev->dev, "building keymap failed\n");
	235	return error;
	236	}
	237
	238	error = devm_request_irq(&pdev->dev, irq, nspire_keypad_irq, 0,
	239	"nspire_keypad", keypad);
	240	if (error) {
	241	dev_err(&pdev->dev, "allocate irq %d failed\n", irq);
	242	return error;
	243	}
	244
	245	error = input_register_device(input);
	246	if (error) {
	247	dev_err(&pdev->dev,
	248	"unable to register input device: %d\n", error);
	249	return error;
	250	}
	251
	252	platform_set_drvdata(pdev, keypad);
	253
	254	dev_dbg(&pdev->dev,
	255	"TI-NSPIRE keypad at %pR (scan_interval=%uus, row_delay=%uus%s)\n",
	256	res, keypad->row_delay, keypad->scan_interval,
	257	keypad->active_low ? ", active_low" : "");
	258
	259	return 0;
	260	}
	261
	262	static const struct of_device_id nspire_keypad_dt_match[] = {
	263	{ .compatible = "ti,nspire-keypad" },
	264	{ },
	265	};
	266	MODULE_DEVICE_TABLE(of, nspire_keypad_dt_match);
	267
	268	static struct platform_driver nspire_keypad_driver = {
	269	.driver = {
	270	.name = "nspire-keypad",
4c93ca5f	271	.of_match_table = nspire_keypad_dt_match,
fc4f3146 DT	272	},
	273	.probe = nspire_keypad_probe,
	274	};
	275
	276	module_platform_driver(nspire_keypad_driver);
	277
	278	MODULE_LICENSE("GPL");
	279	MODULE_DESCRIPTION("TI-NSPIRE Keypad Driver");