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