1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson SA 2010
4 *
5 * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
6 * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
7 *
8 * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
9 * the Nomadik 8815 and Ux500 platforms.
10 */
11
12#include <linux/platform_device.h>
13#include <linux/interrupt.h>
14#include <linux/spinlock.h>
15#include <linux/io.h>
16#include <linux/delay.h>
17#include <linux/input.h>
18#include <linux/slab.h>
19#include <linux/clk.h>
20#include <linux/module.h>
21
22#include <linux/platform_data/keypad-nomadik-ske.h>
23
24/* SKE_CR bits */
25#define SKE_KPMLT	(0x1 << 6)
26#define SKE_KPCN	(0x7 << 3)
27#define SKE_KPASEN	(0x1 << 2)
28#define SKE_KPASON	(0x1 << 7)
29
30/* SKE_IMSC bits */
31#define SKE_KPIMA	(0x1 << 2)
32
33/* SKE_ICR bits */
34#define SKE_KPICS	(0x1 << 3)
35#define SKE_KPICA	(0x1 << 2)
36
37/* SKE_RIS bits */
38#define SKE_KPRISA	(0x1 << 2)
39
40#define SKE_KEYPAD_ROW_SHIFT	3
41#define SKE_KPD_NUM_ROWS	8
42#define SKE_KPD_NUM_COLS	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#define	KEY_PRESSED_DELAY	10
52
53/**
54 * struct ske_keypad  - data structure used by keypad driver
55 * @irq:	irq no
56 * @reg_base:	ske registers base address
57 * @input:	pointer to input device object
58 * @board:	keypad platform device
59 * @keymap:	matrix scan code table for keycodes
60 * @clk:	clock structure pointer
61 * @pclk:	clock structure pointer
62 * @ske_keypad_lock: spinlock protecting the keypad read/writes
63 */
64struct ske_keypad {
65	int irq;
66	void __iomem *reg_base;
67	struct input_dev *input;
68	const struct ske_keypad_platform_data *board;
69	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
70	struct clk *clk;
71	struct clk *pclk;
72	spinlock_t ske_keypad_lock;
73};
74
75static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
76		u8 mask, u8 data)
77{
78	u32 ret;
79
80	spin_lock(&keypad->ske_keypad_lock);
81
82	ret = readl(keypad->reg_base + addr);
83	ret &= ~mask;
84	ret |= data;
85	writel(ret, keypad->reg_base + addr);
86
87	spin_unlock(&keypad->ske_keypad_lock);
88}
89
90/*
91 * ske_keypad_chip_init: init keypad controller configuration
92 *
93 * Enable Multi key press detection, auto scan mode
94 */
95static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
96{
97	u32 value;
98	int timeout = keypad->board->debounce_ms;
99
100	/* check SKE_RIS to be 0 */
101	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
102		cpu_relax();
103
104	if (timeout == -1)
105		return -EINVAL;
106
107	/*
108	 * set debounce value
109	 * keypad dbounce is configured in DBCR[15:8]
110	 * dbounce value in steps of 32/32.768 ms
111	 */
112	spin_lock(&keypad->ske_keypad_lock);
113	value = readl(keypad->reg_base + SKE_DBCR);
114	value = value & 0xff;
115	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
116	writel(value, keypad->reg_base + SKE_DBCR);
117	spin_unlock(&keypad->ske_keypad_lock);
118
119	/* enable multi key detection */
120	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
121
122	/*
123	 * set up the number of columns
124	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
125	 */
126	value = (keypad->board->kcol - 1) << 3;
127	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
128
129	/* clear keypad interrupt for auto(and pending SW) scans */
130	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
131
132	/* un-mask keypad interrupts */
133	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
134
135	/* enable automatic scan */
136	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
137
138	return 0;
139}
140
141static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
142{
143	int row = 0, code, pos;
144	struct input_dev *input = keypad->input;
145	u32 ske_ris;
146	int key_pressed;
147	int num_of_rows;
148
149	/* find out the row */
150	num_of_rows = hweight8(status);
151	do {
152		pos = __ffs(status);
153		row = pos;
154		status &= ~(1 << pos);
155
156		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
157		ske_ris = readl(keypad->reg_base + SKE_RIS);
158		key_pressed = ske_ris & SKE_KPRISA;
159
160		input_event(input, EV_MSC, MSC_SCAN, code);
161		input_report_key(input, keypad->keymap[code], key_pressed);
162		input_sync(input);
163		num_of_rows--;
164	} while (num_of_rows);
165}
166
167static void ske_keypad_read_data(struct ske_keypad *keypad)
168{
169	u8 status;
170	int col = 0;
171	int ske_asr, i;
172
173	/*
174	 * Read the auto scan registers
175	 *
176	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
177	 * lower byte contains row value for column 2*x,
178	 * upper byte contains row value for column 2*x + 1
179	 */
180	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
181		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
182		if (!ske_asr)
183			continue;
184
185		/* now that ASRx is zero, find out the coloumn x and row y */
186		status = ske_asr & 0xff;
187		if (status) {
188			col = i * 2;
189			ske_keypad_report(keypad, status, col);
190		}
191		status = (ske_asr & 0xff00) >> 8;
192		if (status) {
193			col = (i * 2) + 1;
194			ske_keypad_report(keypad, status, col);
195		}
196	}
197}
198
199static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
200{
201	struct ske_keypad *keypad = dev_id;
202	int timeout = keypad->board->debounce_ms;
203
204	/* disable auto scan interrupt; mask the interrupt generated */
205	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
206	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
207
208	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
209		cpu_relax();
210
211	/* SKEx registers are stable and can be read */
212	ske_keypad_read_data(keypad);
213
214	/* wait until raw interrupt is clear */
215	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
216		msleep(KEY_PRESSED_DELAY);
217
218	/* enable auto scan interrupts */
219	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
220
221	return IRQ_HANDLED;
222}
223
224static void ske_keypad_board_exit(void *data)
225{
226	struct ske_keypad *keypad = data;
227
228	keypad->board->exit();
229}
230
231static int __init ske_keypad_probe(struct platform_device *pdev)
232{
233	const struct ske_keypad_platform_data *plat =
234			dev_get_platdata(&pdev->dev);
235	struct device *dev = &pdev->dev;
236	struct ske_keypad *keypad;
237	struct input_dev *input;
238	int irq;
239	int error;
240
241	if (!plat) {
242		dev_err(&pdev->dev, "invalid keypad platform data\n");
243		return -EINVAL;
244	}
245
246	irq = platform_get_irq(pdev, 0);
247	if (irq < 0)
248		return irq;
249
250	keypad = devm_kzalloc(dev, sizeof(struct ske_keypad),
251			      GFP_KERNEL);
252	input = devm_input_allocate_device(dev);
253	if (!keypad || !input) {
254		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
255		return -ENOMEM;
256	}
257
258	keypad->irq = irq;
259	keypad->board = plat;
260	keypad->input = input;
261	spin_lock_init(&keypad->ske_keypad_lock);
262
263	keypad->reg_base = devm_platform_ioremap_resource(pdev, 0);
264	if (IS_ERR(keypad->reg_base))
265		return PTR_ERR(keypad->reg_base);
266
267	keypad->pclk = devm_clk_get_enabled(dev, "apb_pclk");
268	if (IS_ERR(keypad->pclk)) {
269		dev_err(&pdev->dev, "failed to get pclk\n");
270		return PTR_ERR(keypad->pclk);
271	}
272
273	keypad->clk = devm_clk_get_enabled(dev, NULL);
274	if (IS_ERR(keypad->clk)) {
275		dev_err(&pdev->dev, "failed to get clk\n");
276		return PTR_ERR(keypad->clk);
277	}
278
279	input->id.bustype = BUS_HOST;
280	input->name = "ux500-ske-keypad";
281	input->dev.parent = &pdev->dev;
282
283	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
284					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
285					   keypad->keymap, input);
286	if (error) {
287		dev_err(&pdev->dev, "Failed to build keymap\n");
288		return error;
289	}
290
291	input_set_capability(input, EV_MSC, MSC_SCAN);
292	if (!plat->no_autorepeat)
293		__set_bit(EV_REP, input->evbit);
294
295	/* go through board initialization helpers */
296	if (keypad->board->init)
297		keypad->board->init();
298
299	if (keypad->board->exit) {
300		error = devm_add_action_or_reset(dev, ske_keypad_board_exit,
301						 keypad);
302		if (error)
303			return error;
304	}
305
306	error = ske_keypad_chip_init(keypad);
307	if (error) {
308		dev_err(&pdev->dev, "unable to init keypad hardware\n");
309		return error;
310	}
311
312	error = devm_request_threaded_irq(dev, keypad->irq,
313					  NULL, ske_keypad_irq,
314					  IRQF_ONESHOT, "ske-keypad", keypad);
315	if (error) {
316		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
317		return error;
318	}
319
320	error = input_register_device(input);
321	if (error) {
322		dev_err(&pdev->dev,
323			"unable to register input device: %d\n", error);
324		return error;
325	}
326
327	if (plat->wakeup_enable)
328		device_init_wakeup(&pdev->dev, true);
329
330	platform_set_drvdata(pdev, keypad);
331
332	return 0;
333}
334
335static int ske_keypad_suspend(struct device *dev)
336{
337	struct platform_device *pdev = to_platform_device(dev);
338	struct ske_keypad *keypad = platform_get_drvdata(pdev);
339	int irq = platform_get_irq(pdev, 0);
340
341	if (device_may_wakeup(dev))
342		enable_irq_wake(irq);
343	else
344		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
345
346	return 0;
347}
348
349static int ske_keypad_resume(struct device *dev)
350{
351	struct platform_device *pdev = to_platform_device(dev);
352	struct ske_keypad *keypad = platform_get_drvdata(pdev);
353	int irq = platform_get_irq(pdev, 0);
354
355	if (device_may_wakeup(dev))
356		disable_irq_wake(irq);
357	else
358		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
359
360	return 0;
361}
362
363static DEFINE_SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
364				ske_keypad_suspend, ske_keypad_resume);
365
366static struct platform_driver ske_keypad_driver = {
367	.driver = {
368		.name = "nmk-ske-keypad",
369		.pm = pm_sleep_ptr(&ske_keypad_dev_pm_ops),
370	},
371};
372
373module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
374
375MODULE_LICENSE("GPL v2");
376MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
377MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
378MODULE_ALIAS("platform:nomadik-ske-keypad");
379