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
30 struct 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
41 static 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
mt6779_keypad_irq_handler(int irq,void * dev_id)48 static 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
mt6779_keypad_clk_disable(void * data)95 static void mt6779_keypad_clk_disable(void *data)
96 {
97 clk_disable_unprepare(data);
98 }
99
mt6779_keypad_calc_row_col_single(unsigned int key,unsigned int * row,unsigned int * col)100 static 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
mt6779_keypad_calc_row_col_double(unsigned int key,unsigned int * row,unsigned int * col)108 static 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
mt6779_keypad_pdrv_probe(struct platform_device * pdev)116 static 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
258 static const struct of_device_id mt6779_keypad_of_match[] = {
259 { .compatible = "mediatek,mt6779-keypad" },
260 { .compatible = "mediatek,mt6873-keypad" },
261 { /* sentinel */ }
262 };
263
264 static 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 };
271 module_platform_driver(mt6779_keypad_pdrv);
272
273 MODULE_AUTHOR("Mediatek Corporation");
274 MODULE_DESCRIPTION("MTK Keypad (KPD) Driver");
275 MODULE_LICENSE("GPL");
276