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_calc_row_col_single(unsigned int key,
 96					      unsigned int *row,
 97					      unsigned int *col)
 98{
 99	*row = key / 9;
100	*col = key % 9;
101}
102
103static void mt6779_keypad_calc_row_col_double(unsigned int key,
104					      unsigned int *row,
105					      unsigned int *col)
106{
107	*row = key / 13;
108	*col = (key % 13) / 2;
109}
110
111static int mt6779_keypad_pdrv_probe(struct platform_device *pdev)
112{
113	struct mt6779_keypad *keypad;
114	void __iomem *base;
115	int irq;
116	u32 debounce;
117	u32 keys_per_group;
118	bool wakeup;
119	int error;
120
121	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
122	if (!keypad)
123		return -ENOMEM;
124
125	base = devm_platform_ioremap_resource(pdev, 0);
126	if (IS_ERR(base))
127		return PTR_ERR(base);
128
129	keypad->regmap = devm_regmap_init_mmio(&pdev->dev, base,
130					       &mt6779_keypad_regmap_cfg);
131	if (IS_ERR(keypad->regmap)) {
132		dev_err(&pdev->dev,
133			"regmap init failed:%pe\n", keypad->regmap);
134		return PTR_ERR(keypad->regmap);
135	}
136
137	bitmap_fill(keypad->keymap_state, MTK_KPD_NUM_BITS);
138
139	keypad->input_dev = devm_input_allocate_device(&pdev->dev);
140	if (!keypad->input_dev) {
141		dev_err(&pdev->dev, "Failed to allocate input dev\n");
142		return -ENOMEM;
143	}
144
145	keypad->input_dev->name = MTK_KPD_NAME;
146	keypad->input_dev->id.bustype = BUS_HOST;
147
148	error = matrix_keypad_parse_properties(&pdev->dev, &keypad->n_rows,
149					       &keypad->n_cols);
150	if (error) {
151		dev_err(&pdev->dev, "Failed to parse keypad params\n");
152		return error;
153	}
154
155	if (device_property_read_u32(&pdev->dev, "debounce-delay-ms",
156				     &debounce))
157		debounce = 16;
158
159	if (debounce > MTK_KPD_DEBOUNCE_MAX_MS) {
160		dev_err(&pdev->dev,
161			"Debounce time exceeds the maximum allowed time %dms\n",
162			MTK_KPD_DEBOUNCE_MAX_MS);
163		return -EINVAL;
164	}
165
166	if (device_property_read_u32(&pdev->dev, "mediatek,keys-per-group",
167				     &keys_per_group))
168		keys_per_group = 1;
169
170	switch (keys_per_group) {
171	case 1:
172		keypad->calc_row_col = mt6779_keypad_calc_row_col_single;
173		break;
174	case 2:
175		keypad->calc_row_col = mt6779_keypad_calc_row_col_double;
176		break;
177	default:
178		dev_err(&pdev->dev,
179			"Invalid keys-per-group: %d\n", keys_per_group);
180		return -EINVAL;
181	}
182
183	wakeup = device_property_read_bool(&pdev->dev, "wakeup-source");
184
185	dev_dbg(&pdev->dev, "n_row=%d n_col=%d debounce=%d\n",
186		keypad->n_rows, keypad->n_cols, debounce);
187
188	error = matrix_keypad_build_keymap(NULL, NULL,
189					   keypad->n_rows, keypad->n_cols,
190					   NULL, keypad->input_dev);
191	if (error) {
192		dev_err(&pdev->dev, "Failed to build keymap\n");
193		return error;
194	}
195
196	input_set_capability(keypad->input_dev, EV_MSC, MSC_SCAN);
197
198	regmap_write(keypad->regmap, MTK_KPD_DEBOUNCE,
199		     (debounce * (1 << 5)) & MTK_KPD_DEBOUNCE_MASK);
200
201	if (keys_per_group == 2)
202		regmap_update_bits(keypad->regmap, MTK_KPD_SEL,
203				   MTK_KPD_SEL_DOUBLE_KP_MODE,
204				   MTK_KPD_SEL_DOUBLE_KP_MODE);
205
206	regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_ROW,
207			   MTK_KPD_SEL_ROWMASK(keypad->n_rows));
208	regmap_update_bits(keypad->regmap, MTK_KPD_SEL, MTK_KPD_SEL_COL,
209			   MTK_KPD_SEL_COLMASK(keypad->n_cols));
210
211	keypad->clk = devm_clk_get_enabled(&pdev->dev, "kpd");
212	if (IS_ERR(keypad->clk))
213		return PTR_ERR(keypad->clk);
214
215	irq = platform_get_irq(pdev, 0);
216	if (irq < 0)
217		return irq;
218
219	error = devm_request_threaded_irq(&pdev->dev, irq,
220					  NULL, mt6779_keypad_irq_handler,
221					  IRQF_ONESHOT, MTK_KPD_NAME, keypad);
222	if (error) {
223		dev_err(&pdev->dev, "Failed to request IRQ#%d: %d\n",
224			irq, error);
225		return error;
226	}
227
228	error = input_register_device(keypad->input_dev);
229	if (error) {
230		dev_err(&pdev->dev, "Failed to register device\n");
231		return error;
232	}
233
234	error = device_init_wakeup(&pdev->dev, wakeup);
235	if (error)
236		dev_warn(&pdev->dev, "device_init_wakeup() failed: %d\n",
237			 error);
238
239	return 0;
240}
241
242static const struct of_device_id mt6779_keypad_of_match[] = {
243	{ .compatible = "mediatek,mt6779-keypad" },
244	{ .compatible = "mediatek,mt6873-keypad" },
245	{ /* sentinel */ }
246};
247MODULE_DEVICE_TABLE(of, mt6779_keypad_of_match);
248
249static struct platform_driver mt6779_keypad_pdrv = {
250	.probe = mt6779_keypad_pdrv_probe,
251	.driver = {
252		   .name = MTK_KPD_NAME,
253		   .of_match_table = mt6779_keypad_of_match,
254	},
255};
256module_platform_driver(mt6779_keypad_pdrv);
257
258MODULE_AUTHOR("Mediatek Corporation");
259MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
260MODULE_LICENSE("GPL");