1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2022 MediaTek Inc.
4 * Author Fengping Yu <fengping.yu@mediatek.com>
5 */
6#include <linux/bitops.h>
7#include <linux/clk.h>
8#include <linux/input.h>
9#include <linux/input/matrix_keypad.h>
10#include <linux/interrupt.h>
11#include <linux/module.h>
12#include <linux/property.h>
13#include <linux/platform_device.h>
14#include <linux/regmap.h>
15
16#define MTK_KPD_NAME		"mt6779-keypad"
17#define MTK_KPD_MEM		0x0004
18#define MTK_KPD_DEBOUNCE	0x0018
19#define MTK_KPD_DEBOUNCE_MASK	GENMASK(13, 0)
20#define MTK_KPD_DEBOUNCE_MAX_MS	256
21#define MTK_KPD_SEL		0x0020
22#define MTK_KPD_SEL_DOUBLE_KP_MODE	BIT(0)
23#define MTK_KPD_SEL_COL	GENMASK(15, 10)
24#define MTK_KPD_SEL_ROW	GENMASK(9, 4)
25#define MTK_KPD_SEL_COLMASK(c)	GENMASK((c) + 9, 10)
26#define MTK_KPD_SEL_ROWMASK(r)	GENMASK((r) + 3, 4)
27#define MTK_KPD_NUM_MEMS	5
28#define MTK_KPD_NUM_BITS	136	/* 4*32+8 MEM5 only use 8 BITS */
29
30struct mt6779_keypad {
31	struct regmap *regmap;
32	struct input_dev *input_dev;
33	struct clk *clk;
34	u32 n_rows;
35	u32 n_cols;
36	void (*calc_row_col)(unsigned int key,
37			     unsigned int *row, unsigned int *col);
38	DECLARE_BITMAP(keymap_state, MTK_KPD_NUM_BITS);
39};
40
41static const struct regmap_config mt6779_keypad_regmap_cfg = {
42	.reg_bits = 32,
43	.val_bits = 32,
44	.reg_stride = sizeof(u32),
45	.max_register = 36,
46};
47
48static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id)
49{
50	struct mt6779_keypad *keypad = dev_id;
51	const unsigned short *keycode = keypad->input_dev->keycode;
52	DECLARE_BITMAP(new_state, MTK_KPD_NUM_BITS);
53	DECLARE_BITMAP(change, MTK_KPD_NUM_BITS);
54	unsigned int bit_nr, key;
55	unsigned int row, col;
56	unsigned int scancode;
57	unsigned int row_shift = get_count_order(keypad->n_cols);
58	bool pressed;
59
60	regmap_bulk_read(keypad->regmap, MTK_KPD_MEM,
61			 new_state, MTK_KPD_NUM_MEMS);
62
63	bitmap_xor(change, new_state, keypad->keymap_state, MTK_KPD_NUM_BITS);
64
65	for_each_set_bit(bit_nr, change, MTK_KPD_NUM_BITS) {
66		/*
67		 * Registers are 32bits, but only bits [15:0] are used to
68		 * indicate key status.
69		 */
70		if (bit_nr % 32 >= 16)
71			continue;
72
73		key = bit_nr / 32 * 16 + bit_nr % 32;
74		keypad->calc_row_col(key, &row, &col);
75
76		scancode = MATRIX_SCAN_CODE(row, col, row_shift);
77		/* 1: not pressed, 0: pressed */
78		pressed = !test_bit(bit_nr, new_state);
79		dev_dbg(&keypad->input_dev->dev, "%s",
80			pressed ? "pressed" : "released");
81
82		input_event(keypad->input_dev, EV_MSC, MSC_SCAN, scancode);
83		input_report_key(keypad->input_dev, keycode[scancode], pressed);
84		input_sync(keypad->input_dev);
85
86		dev_dbg(&keypad->input_dev->dev,
87			"report Linux keycode = %d\n", keycode[scancode]);
88	}
89
90	bitmap_copy(keypad->keymap_state, new_state, MTK_KPD_NUM_BITS);
91
92	return IRQ_HANDLED;
93}
94
95static void mt6779_keypad_clk_disable(void *data)
96{
97	clk_disable_unprepare(data);
98}
99
100static void mt6779_keypad_calc_row_col_single(unsigned int key,
101					      unsigned int *row,
102					      unsigned int *col)
103{
104	*row = key / 9;
105	*col = key % 9;
106}
107
108static void mt6779_keypad_calc_row_col_double(unsigned int key,
109					      unsigned int *row,
110					      unsigned int *col)
111{
112	*row = key / 13;
113	*col = (key % 13) / 2;
114}
115
116static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
117{
118	struct mt6779_keypad *keypad;
119	void __iomem *base;
120	int irq;
121	u32 debounce;
122	u32 keys_per_group;
123	bool wakeup;
124	int error;
125
126	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
127	if (!keypad)
128		return -ENOMEM;
129
130	base = devm_platform_ioremap_resource(pdev, 0);
131	if (IS_ERR(base))
132		return PTR_ERR(base);
133
134	keypad->regmap = devm_regmap_init_mmio(&pdev->dev, base,
135					       &mt6779_keypad_regmap_cfg);
136	if (IS_ERR(keypad->regmap)) {
137		dev_err(&pdev->dev,
138			"regmap init failed:%pe\n", keypad->regmap);
139		return PTR_ERR(keypad->regmap);
140	}
141
142	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
143
144	keypad->input_dev = devm_input_allocate_device(&pdev->dev);
145	if (!keypad->input_dev) {
146		dev_err(&pdev->dev, "Failed to allocate input dev\n");
147		return -ENOMEM;
148	}
149
150	keypad->input_dev->name = MTK_KPD_NAME;
151	keypad->input_dev->id.bustype = BUS_HOST;
152
153	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
154					       &keypad->n_cols);
155	if (error) {
156		dev_err(&pdev->dev, "Failed to parse keypad params\n");
157		return error;
158	}
159
160	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
161				     &debounce))
162		debounce = 16;
163
164	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
165		dev_err(&pdev->dev,
166			"Debounce time exceeds the maximum allowed time %dms\n",
167			MTK_KPD_DEBOUNCE_MAX_MS);
168		return -EINVAL;
169	}
170
171	if (device_property_read_u32(&pdev->dev, "mediatek,keys-per-group",
172				     &keys_per_group))
173		keys_per_group = 1;
174
175	switch (keys_per_group) {
176	case 1:
177		keypad->calc_row_col = mt6779_keypad_calc_row_col_single;
178		break;
179	case 2:
180		keypad->calc_row_col = mt6779_keypad_calc_row_col_double;
181		break;
182	default:
183		dev_err(&pdev->dev,
184			"Invalid keys-per-group: %d\n", keys_per_group);
185		return -EINVAL;
186	}
187
188	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
189
190	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
191		keypad->n_rows, keypad->n_cols, debounce);
192
193	error = matrix_keypad_build_keymap(NULL, NULL,
194					   keypad->n_rows, keypad->n_cols,
195					   NULL, keypad->input_dev);
196	if (error) {
197		dev_err(&pdev->dev, "Failed to build keymap\n");
198		return error;
199	}
200
201	input_set_capability(keypad->input_dev, EV_MSC, MSC_SCAN);
202
203	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
204		     (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
205
206	if (keys_per_group == 2)
207		regmap_update_bits(keypad->regmap, MTK_KPD_SEL,
208				   MTK_KPD_SEL_DOUBLE_KP_MODE,
209				   MTK_KPD_SEL_DOUBLE_KP_MODE);
210
211	regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_ROW,
212			   MTK_KPD_SEL_ROWMASK(keypad->n_rows));
213	regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_COL,
214			   MTK_KPD_SEL_COLMASK(keypad->n_cols));
215
216	keypad->clk = devm_clk_get(&pdev->dev, "kpd");
217	if (IS_ERR(keypad->clk))
218		return PTR_ERR(keypad->clk);
219
220	error = clk_prepare_enable(keypad->clk);
221	if (error) {
222		dev_err(&pdev->dev, "cannot prepare/enable keypad clock\n");
223		return error;
224	}
225
226	error = devm_add_action_or_reset(&pdev->dev, mt6779_keypad_clk_disable,
227					 keypad->clk);
228	if (error)
229		return error;
230
231	irq = platform_get_irq(pdev, 0);
232	if (irq < 0)
233		return irq;
234
235	error = devm_request_threaded_irq(&pdev->dev, irq,
236					  NULL, mt6779_keypad_irq_handler,
237					  IRQF_ONESHOT, MTK_KPD_NAME, keypad);
238	if (error) {
239		dev_err(&pdev->dev, "Failed to request IRQ#%d: %d\n",
240			irq, error);
241		return error;
242	}
243
244	error = input_register_device(keypad->input_dev);
245	if (error) {
246		dev_err(&pdev->dev, "Failed to register device\n");
247		return error;
248	}
249
250	error = device_init_wakeup(&pdev->dev, wakeup);
251	if (error)
252		dev_warn(&pdev->dev, "device_init_wakeup() failed: %d\n",
253			 error);
254
255	return 0;
256}
257
258static const struct of_device_id mt6779_keypad_of_match[] = {
259	{ .compatible = "mediatek,mt6779-keypad" },
260	{ .compatible = "mediatek,mt6873-keypad" },
261	{ /* sentinel */ }
262};
263
264static struct platform_driver mt6779_keypad_pdrv = {
265	.probe = mt6779_keypad_pdrv_probe,
266	.driver = {
267		   .name = MTK_KPD_NAME,
268		   .of_match_table = mt6779_keypad_of_match,
269	},
270};
271module_platform_driver(mt6779_keypad_pdrv);
272
273MODULE_AUTHOR("Mediatek Corporation");
274MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
275MODULE_LICENSE("GPL");
276