1/*
2 * Copyright (C) ST-Ericsson SA 2010
3 *
4 * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
5 * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
6 *
7 * License terms:GNU General Public License (GPL) version 2
8 *
9 * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
10 * the Nomadik 8815 and Ux500 platforms.
11 */
12
13#include <linux/platform_device.h>
14#include <linux/interrupt.h>
15#include <linux/spinlock.h>
16#include <linux/io.h>
17#include <linux/delay.h>
18#include <linux/input.h>
19#include <linux/slab.h>
20#include <linux/clk.h>
21#include <linux/module.h>
22
23#include <plat/ske.h>
24
25/* SKE_CR bits */
26#define SKE_KPMLT	(0x1 << 6)
27#define SKE_KPCN	(0x7 << 3)
28#define SKE_KPASEN	(0x1 << 2)
29#define SKE_KPASON	(0x1 << 7)
30
31/* SKE_IMSC bits */
32#define SKE_KPIMA	(0x1 << 2)
33
34/* SKE_ICR bits */
35#define SKE_KPICS	(0x1 << 3)
36#define SKE_KPICA	(0x1 << 2)
37
38/* SKE_RIS bits */
39#define SKE_KPRISA	(0x1 << 2)
40
41#define SKE_KEYPAD_ROW_SHIFT	3
42#define SKE_KPD_KEYMAP_SIZE	(8 * 8)
43
44/* keypad auto scan registers */
45#define SKE_ASR0	0x20
46#define SKE_ASR1	0x24
47#define SKE_ASR2	0x28
48#define SKE_ASR3	0x2C
49
50#define SKE_NUM_ASRX_REGISTERS	(4)
51
52/**
53 * struct ske_keypad  - data structure used by keypad driver
54 * @irq:	irq no
55 * @reg_base:	ske regsiters base address
56 * @input:	pointer to input device object
57 * @board:	keypad platform device
58 * @keymap:	matrix scan code table for keycodes
59 * @clk:	clock structure pointer
60 */
61struct ske_keypad {
62	int irq;
63	void __iomem *reg_base;
64	struct input_dev *input;
65	const struct ske_keypad_platform_data *board;
66	unsigned short keymap[SKE_KPD_KEYMAP_SIZE];
67	struct clk *clk;
68	spinlock_t ske_keypad_lock;
69};
70
71static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
72		u8 mask, u8 data)
73{
74	u32 ret;
75
76	spin_lock(&keypad->ske_keypad_lock);
77
78	ret = readl(keypad->reg_base + addr);
79	ret &= ~mask;
80	ret |= data;
81	writel(ret, keypad->reg_base + addr);
82
83	spin_unlock(&keypad->ske_keypad_lock);
84}
85
86/*
87 * ske_keypad_chip_init: init keypad controller configuration
88 *
89 * Enable Multi key press detection, auto scan mode
90 */
91static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
92{
93	u32 value;
94	int timeout = 50;
95
96	/* check SKE_RIS to be 0 */
97	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
98		cpu_relax();
99
100	if (!timeout)
101		return -EINVAL;
102
103	/*
104	 * set debounce value
105	 * keypad dbounce is configured in DBCR[15:8]
106	 * dbounce value in steps of 32/32.768 ms
107	 */
108	spin_lock(&keypad->ske_keypad_lock);
109	value = readl(keypad->reg_base + SKE_DBCR);
110	value = value & 0xff;
111	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
112	writel(value, keypad->reg_base + SKE_DBCR);
113	spin_unlock(&keypad->ske_keypad_lock);
114
115	/* enable multi key detection */
116	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
117
118	/*
119	 * set up the number of columns
120	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
121	 */
122	value = (keypad->board->kcol - 1) << 3;
123	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
124
125	/* clear keypad interrupt for auto(and pending SW) scans */
126	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
127
128	/* un-mask keypad interrupts */
129	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
130
131	/* enable automatic scan */
132	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
133
134	return 0;
135}
136
137static void ske_keypad_read_data(struct ske_keypad *keypad)
138{
139	struct input_dev *input = keypad->input;
140	u16 status;
141	int col = 0, row = 0, code;
142	int ske_asr, ske_ris, key_pressed, i;
143
144	/*
145	 * Read the auto scan registers
146	 *
147	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
148	 * lower byte contains row value for column 2*x,
149	 * upper byte contains row value for column 2*x + 1
150	 */
151	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
152		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
153		if (!ske_asr)
154			continue;
155
156		/* now that ASRx is zero, find out the column x and row y*/
157		if (ske_asr & 0xff) {
158			col = i * 2;
159			status = ske_asr & 0xff;
160		} else {
161			col = (i * 2) + 1;
162			status = (ske_asr & 0xff00) >> 8;
163		}
164
165		/* find out the row */
166		row = __ffs(status);
167
168		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
169		ske_ris = readl(keypad->reg_base + SKE_RIS);
170		key_pressed = ske_ris & SKE_KPRISA;
171
172		input_event(input, EV_MSC, MSC_SCAN, code);
173		input_report_key(input, keypad->keymap[code], key_pressed);
174		input_sync(input);
175	}
176}
177
178static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
179{
180	struct ske_keypad *keypad = dev_id;
181	int retries = 20;
182
183	/* disable auto scan interrupt; mask the interrupt generated */
184	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
185	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
186
187	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --retries)
188		msleep(5);
189
190	if (retries) {
191		/* SKEx registers are stable and can be read */
192		ske_keypad_read_data(keypad);
193	}
194
195	/* enable auto scan interrupts */
196	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
197
198	return IRQ_HANDLED;
199}
200
201static int __init ske_keypad_probe(struct platform_device *pdev)
202{
203	const struct ske_keypad_platform_data *plat = pdev->dev.platform_data;
204	struct ske_keypad *keypad;
205	struct input_dev *input;
206	struct resource *res;
207	int irq;
208	int error;
209
210	if (!plat) {
211		dev_err(&pdev->dev, "invalid keypad platform data\n");
212		return -EINVAL;
213	}
214
215	irq = platform_get_irq(pdev, 0);
216	if (irq < 0) {
217		dev_err(&pdev->dev, "failed to get keypad irq\n");
218		return -EINVAL;
219	}
220
221	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
222	if (!res) {
223		dev_err(&pdev->dev, "missing platform resources\n");
224		return -EINVAL;
225	}
226
227	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
228	input = input_allocate_device();
229	if (!keypad || !input) {
230		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
231		error = -ENOMEM;
232		goto err_free_mem;
233	}
234
235	keypad->irq = irq;
236	keypad->board = plat;
237	keypad->input = input;
238	spin_lock_init(&keypad->ske_keypad_lock);
239
240	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
241		dev_err(&pdev->dev, "failed to request I/O memory\n");
242		error = -EBUSY;
243		goto err_free_mem;
244	}
245
246	keypad->reg_base = ioremap(res->start, resource_size(res));
247	if (!keypad->reg_base) {
248		dev_err(&pdev->dev, "failed to remap I/O memory\n");
249		error = -ENXIO;
250		goto err_free_mem_region;
251	}
252
253	keypad->clk = clk_get(&pdev->dev, NULL);
254	if (IS_ERR(keypad->clk)) {
255		dev_err(&pdev->dev, "failed to get clk\n");
256		error = PTR_ERR(keypad->clk);
257		goto err_iounmap;
258	}
259
260	input->id.bustype = BUS_HOST;
261	input->name = "ux500-ske-keypad";
262	input->dev.parent = &pdev->dev;
263
264	input->keycode = keypad->keymap;
265	input->keycodesize = sizeof(keypad->keymap[0]);
266	input->keycodemax = ARRAY_SIZE(keypad->keymap);
267
268	input_set_capability(input, EV_MSC, MSC_SCAN);
269
270	__set_bit(EV_KEY, input->evbit);
271	if (!plat->no_autorepeat)
272		__set_bit(EV_REP, input->evbit);
273
274	matrix_keypad_build_keymap(plat->keymap_data, SKE_KEYPAD_ROW_SHIFT,
275			input->keycode, input->keybit);
276
277	clk_enable(keypad->clk);
278
279	/* go through board initialization helpers */
280	if (keypad->board->init)
281		keypad->board->init();
282
283	error = ske_keypad_chip_init(keypad);
284	if (error) {
285		dev_err(&pdev->dev, "unable to init keypad hardware\n");
286		goto err_clk_disable;
287	}
288
289	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
290				     IRQF_ONESHOT, "ske-keypad", keypad);
291	if (error) {
292		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
293		goto err_clk_disable;
294	}
295
296	error = input_register_device(input);
297	if (error) {
298		dev_err(&pdev->dev,
299				"unable to register input device: %d\n", error);
300		goto err_free_irq;
301	}
302
303	if (plat->wakeup_enable)
304		device_init_wakeup(&pdev->dev, true);
305
306	platform_set_drvdata(pdev, keypad);
307
308	return 0;
309
310err_free_irq:
311	free_irq(keypad->irq, keypad);
312err_clk_disable:
313	clk_disable(keypad->clk);
314	clk_put(keypad->clk);
315err_iounmap:
316	iounmap(keypad->reg_base);
317err_free_mem_region:
318	release_mem_region(res->start, resource_size(res));
319err_free_mem:
320	input_free_device(input);
321	kfree(keypad);
322	return error;
323}
324
325static int __devexit ske_keypad_remove(struct platform_device *pdev)
326{
327	struct ske_keypad *keypad = platform_get_drvdata(pdev);
328	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
329
330	free_irq(keypad->irq, keypad);
331
332	input_unregister_device(keypad->input);
333
334	clk_disable(keypad->clk);
335	clk_put(keypad->clk);
336
337	if (keypad->board->exit)
338		keypad->board->exit();
339
340	iounmap(keypad->reg_base);
341	release_mem_region(res->start, resource_size(res));
342	kfree(keypad);
343
344	return 0;
345}
346
347#ifdef CONFIG_PM_SLEEP
348static int ske_keypad_suspend(struct device *dev)
349{
350	struct platform_device *pdev = to_platform_device(dev);
351	struct ske_keypad *keypad = platform_get_drvdata(pdev);
352	int irq = platform_get_irq(pdev, 0);
353
354	if (device_may_wakeup(dev))
355		enable_irq_wake(irq);
356	else
357		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
358
359	return 0;
360}
361
362static int ske_keypad_resume(struct device *dev)
363{
364	struct platform_device *pdev = to_platform_device(dev);
365	struct ske_keypad *keypad = platform_get_drvdata(pdev);
366	int irq = platform_get_irq(pdev, 0);
367
368	if (device_may_wakeup(dev))
369		disable_irq_wake(irq);
370	else
371		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
372
373	return 0;
374}
375#endif
376
377static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
378			 ske_keypad_suspend, ske_keypad_resume);
379
380static struct platform_driver ske_keypad_driver = {
381	.driver = {
382		.name = "nmk-ske-keypad",
383		.owner  = THIS_MODULE,
384		.pm = &ske_keypad_dev_pm_ops,
385	},
386	.remove = __devexit_p(ske_keypad_remove),
387};
388
389static int __init ske_keypad_init(void)
390{
391	return platform_driver_probe(&ske_keypad_driver, ske_keypad_probe);
392}
393module_init(ske_keypad_init);
394
395static void __exit ske_keypad_exit(void)
396{
397	platform_driver_unregister(&ske_keypad_driver);
398}
399module_exit(ske_keypad_exit);
400
401MODULE_LICENSE("GPL v2");
402MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
403MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
404MODULE_ALIAS("platform:nomadik-ske-keypad");
405