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 <linux/platform_data/keypad-nomadik-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_NUM_ROWS	8
43#define SKE_KPD_NUM_COLS	8
44
45/* keypad auto scan registers */
46#define SKE_ASR0	0x20
47#define SKE_ASR1	0x24
48#define SKE_ASR2	0x28
49#define SKE_ASR3	0x2C
50
51#define SKE_NUM_ASRX_REGISTERS	(4)
52#define	KEY_PRESSED_DELAY	10
53
54/**
55 * struct ske_keypad  - data structure used by keypad driver
56 * @irq:	irq no
57 * @reg_base:	ske registers base address
58 * @input:	pointer to input device object
59 * @board:	keypad platform device
60 * @keymap:	matrix scan code table for keycodes
61 * @clk:	clock structure pointer
62 */
63struct ske_keypad {
64	int irq;
65	void __iomem *reg_base;
66	struct input_dev *input;
67	const struct ske_keypad_platform_data *board;
68	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
69	struct clk *clk;
70	struct clk *pclk;
71	spinlock_t ske_keypad_lock;
72};
73
74static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
75		u8 mask, u8 data)
76{
77	u32 ret;
78
79	spin_lock(&keypad->ske_keypad_lock);
80
81	ret = readl(keypad->reg_base + addr);
82	ret &= ~mask;
83	ret |= data;
84	writel(ret, keypad->reg_base + addr);
85
86	spin_unlock(&keypad->ske_keypad_lock);
87}
88
89/*
90 * ske_keypad_chip_init: init keypad controller configuration
91 *
92 * Enable Multi key press detection, auto scan mode
93 */
94static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
95{
96	u32 value;
97	int timeout = keypad->board->debounce_ms;
98
99	/* check SKE_RIS to be 0 */
100	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
101		cpu_relax();
102
103	if (!timeout)
104		return -EINVAL;
105
106	/*
107	 * set debounce value
108	 * keypad dbounce is configured in DBCR[15:8]
109	 * dbounce value in steps of 32/32.768 ms
110	 */
111	spin_lock(&keypad->ske_keypad_lock);
112	value = readl(keypad->reg_base + SKE_DBCR);
113	value = value & 0xff;
114	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
115	writel(value, keypad->reg_base + SKE_DBCR);
116	spin_unlock(&keypad->ske_keypad_lock);
117
118	/* enable multi key detection */
119	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
120
121	/*
122	 * set up the number of columns
123	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
124	 */
125	value = (keypad->board->kcol - 1) << 3;
126	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
127
128	/* clear keypad interrupt for auto(and pending SW) scans */
129	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
130
131	/* un-mask keypad interrupts */
132	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
133
134	/* enable automatic scan */
135	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
136
137	return 0;
138}
139
140static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
141{
142	int row = 0, code, pos;
143	struct input_dev *input = keypad->input;
144	u32 ske_ris;
145	int key_pressed;
146	int num_of_rows;
147
148	/* find out the row */
149	num_of_rows = hweight8(status);
150	do {
151		pos = __ffs(status);
152		row = pos;
153		status &= ~(1 << pos);
154
155		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
156		ske_ris = readl(keypad->reg_base + SKE_RIS);
157		key_pressed = ske_ris & SKE_KPRISA;
158
159		input_event(input, EV_MSC, MSC_SCAN, code);
160		input_report_key(input, keypad->keymap[code], key_pressed);
161		input_sync(input);
162		num_of_rows--;
163	} while (num_of_rows);
164}
165
166static void ske_keypad_read_data(struct ske_keypad *keypad)
167{
168	u8 status;
169	int col = 0;
170	int ske_asr, i;
171
172	/*
173	 * Read the auto scan registers
174	 *
175	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
176	 * lower byte contains row value for column 2*x,
177	 * upper byte contains row value for column 2*x + 1
178	 */
179	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
180		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
181		if (!ske_asr)
182			continue;
183
184		/* now that ASRx is zero, find out the coloumn x and row y */
185		status = ske_asr & 0xff;
186		if (status) {
187			col = i * 2;
188			ske_keypad_report(keypad, status, col);
189		}
190		status = (ske_asr & 0xff00) >> 8;
191		if (status) {
192			col = (i * 2) + 1;
193			ske_keypad_report(keypad, status, col);
194		}
195	}
196}
197
198static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
199{
200	struct ske_keypad *keypad = dev_id;
201	int timeout = keypad->board->debounce_ms;
202
203	/* disable auto scan interrupt; mask the interrupt generated */
204	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
205	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
206
207	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
208		cpu_relax();
209
210	/* SKEx registers are stable and can be read */
211	ske_keypad_read_data(keypad);
212
213	/* wait until raw interrupt is clear */
214	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
215		msleep(KEY_PRESSED_DELAY);
216
217	/* enable auto scan interrupts */
218	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
219
220	return IRQ_HANDLED;
221}
222
223static int __init ske_keypad_probe(struct platform_device *pdev)
224{
225	const struct ske_keypad_platform_data *plat =
226			dev_get_platdata(&pdev->dev);
227	struct ske_keypad *keypad;
228	struct input_dev *input;
229	struct resource *res;
230	int irq;
231	int error;
232
233	if (!plat) {
234		dev_err(&pdev->dev, "invalid keypad platform data\n");
235		return -EINVAL;
236	}
237
238	irq = platform_get_irq(pdev, 0);
239	if (irq < 0) {
240		dev_err(&pdev->dev, "failed to get keypad irq\n");
241		return -EINVAL;
242	}
243
244	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
245	if (!res) {
246		dev_err(&pdev->dev, "missing platform resources\n");
247		return -EINVAL;
248	}
249
250	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
251	input = input_allocate_device();
252	if (!keypad || !input) {
253		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
254		error = -ENOMEM;
255		goto err_free_mem;
256	}
257
258	keypad->irq = irq;
259	keypad->board = plat;
260	keypad->input = input;
261	spin_lock_init(&keypad->ske_keypad_lock);
262
263	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
264		dev_err(&pdev->dev, "failed to request I/O memory\n");
265		error = -EBUSY;
266		goto err_free_mem;
267	}
268
269	keypad->reg_base = ioremap(res->start, resource_size(res));
270	if (!keypad->reg_base) {
271		dev_err(&pdev->dev, "failed to remap I/O memory\n");
272		error = -ENXIO;
273		goto err_free_mem_region;
274	}
275
276	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
277	if (IS_ERR(keypad->pclk)) {
278		dev_err(&pdev->dev, "failed to get pclk\n");
279		error = PTR_ERR(keypad->pclk);
280		goto err_iounmap;
281	}
282
283	keypad->clk = clk_get(&pdev->dev, NULL);
284	if (IS_ERR(keypad->clk)) {
285		dev_err(&pdev->dev, "failed to get clk\n");
286		error = PTR_ERR(keypad->clk);
287		goto err_pclk;
288	}
289
290	input->id.bustype = BUS_HOST;
291	input->name = "ux500-ske-keypad";
292	input->dev.parent = &pdev->dev;
293
294	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
295					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
296					   keypad->keymap, input);
297	if (error) {
298		dev_err(&pdev->dev, "Failed to build keymap\n");
299		goto err_clk;
300	}
301
302	input_set_capability(input, EV_MSC, MSC_SCAN);
303	if (!plat->no_autorepeat)
304		__set_bit(EV_REP, input->evbit);
305
306	error = clk_prepare_enable(keypad->pclk);
307	if (error) {
308		dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
309		goto err_clk;
310	}
311
312	error = clk_prepare_enable(keypad->clk);
313	if (error) {
314		dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
315		goto err_pclk_disable;
316	}
317
318
319	/* go through board initialization helpers */
320	if (keypad->board->init)
321		keypad->board->init();
322
323	error = ske_keypad_chip_init(keypad);
324	if (error) {
325		dev_err(&pdev->dev, "unable to init keypad hardware\n");
326		goto err_clk_disable;
327	}
328
329	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
330				     IRQF_ONESHOT, "ske-keypad", keypad);
331	if (error) {
332		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
333		goto err_clk_disable;
334	}
335
336	error = input_register_device(input);
337	if (error) {
338		dev_err(&pdev->dev,
339				"unable to register input device: %d\n", error);
340		goto err_free_irq;
341	}
342
343	if (plat->wakeup_enable)
344		device_init_wakeup(&pdev->dev, true);
345
346	platform_set_drvdata(pdev, keypad);
347
348	return 0;
349
350err_free_irq:
351	free_irq(keypad->irq, keypad);
352err_clk_disable:
353	clk_disable_unprepare(keypad->clk);
354err_pclk_disable:
355	clk_disable_unprepare(keypad->pclk);
356err_clk:
357	clk_put(keypad->clk);
358err_pclk:
359	clk_put(keypad->pclk);
360err_iounmap:
361	iounmap(keypad->reg_base);
362err_free_mem_region:
363	release_mem_region(res->start, resource_size(res));
364err_free_mem:
365	input_free_device(input);
366	kfree(keypad);
367	return error;
368}
369
370static int ske_keypad_remove(struct platform_device *pdev)
371{
372	struct ske_keypad *keypad = platform_get_drvdata(pdev);
373	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
374
375	free_irq(keypad->irq, keypad);
376
377	input_unregister_device(keypad->input);
378
379	clk_disable_unprepare(keypad->clk);
380	clk_put(keypad->clk);
381
382	if (keypad->board->exit)
383		keypad->board->exit();
384
385	iounmap(keypad->reg_base);
386	release_mem_region(res->start, resource_size(res));
387	kfree(keypad);
388
389	return 0;
390}
391
392#ifdef CONFIG_PM_SLEEP
393static int ske_keypad_suspend(struct device *dev)
394{
395	struct platform_device *pdev = to_platform_device(dev);
396	struct ske_keypad *keypad = platform_get_drvdata(pdev);
397	int irq = platform_get_irq(pdev, 0);
398
399	if (device_may_wakeup(dev))
400		enable_irq_wake(irq);
401	else
402		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
403
404	return 0;
405}
406
407static int ske_keypad_resume(struct device *dev)
408{
409	struct platform_device *pdev = to_platform_device(dev);
410	struct ske_keypad *keypad = platform_get_drvdata(pdev);
411	int irq = platform_get_irq(pdev, 0);
412
413	if (device_may_wakeup(dev))
414		disable_irq_wake(irq);
415	else
416		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
417
418	return 0;
419}
420#endif
421
422static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
423			 ske_keypad_suspend, ske_keypad_resume);
424
425static struct platform_driver ske_keypad_driver = {
426	.driver = {
427		.name = "nmk-ske-keypad",
428		.pm = &ske_keypad_dev_pm_ops,
429	},
430	.remove = ske_keypad_remove,
431};
432
433module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
434
435MODULE_LICENSE("GPL v2");
436MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
437MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
438MODULE_ALIAS("platform:nomadik-ske-keypad");
439