1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * STMicroelectronics Key Scanning driver
4 *
5 * Copyright (c) 2014 STMicroelectonics Ltd.
6 * Author: Stuart Menefy <stuart.menefy@st.com>
7 *
8 * Based on sh_keysc.c, copyright 2008 Magnus Damm
9 */
10
11 #include <linux/clk.h>
12 #include <linux/input.h>
13 #include <linux/input/matrix_keypad.h>
14 #include <linux/io.h>
15 #include <linux/interrupt.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19
20 #define ST_KEYSCAN_MAXKEYS 16
21
22 #define KEYSCAN_CONFIG_OFF 0x0
23 #define KEYSCAN_CONFIG_ENABLE 0x1
24 #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4
25 #define KEYSCAN_MATRIX_STATE_OFF 0x8
26 #define KEYSCAN_MATRIX_DIM_OFF 0xc
27 #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0
28 #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2
29
30 struct st_keyscan {
31 void __iomem *base;
32 int irq;
33 struct clk *clk;
34 struct input_dev *input_dev;
35 unsigned long last_state;
36 unsigned int n_rows;
37 unsigned int n_cols;
38 unsigned int debounce_us;
39 };
40
keyscan_isr(int irq,void * dev_id)41 static irqreturn_t keyscan_isr(int irq, void *dev_id)
42 {
43 struct st_keyscan *keypad = dev_id;
44 unsigned short *keycode = keypad->input_dev->keycode;
45 unsigned long state, change;
46 int bit_nr;
47
48 state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff;
49 change = keypad->last_state ^ state;
50 keypad->last_state = state;
51
52 for_each_set_bit(bit_nr, &change, BITS_PER_LONG)
53 input_report_key(keypad->input_dev,
54 keycode[bit_nr], state & BIT(bit_nr));
55
56 input_sync(keypad->input_dev);
57
58 return IRQ_HANDLED;
59 }
60
keyscan_start(struct st_keyscan * keypad)61 static int keyscan_start(struct st_keyscan *keypad)
62 {
63 int error;
64
65 error = clk_enable(keypad->clk);
66 if (error)
67 return error;
68
69 writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000),
70 keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF);
71
72 writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) |
73 ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT),
74 keypad->base + KEYSCAN_MATRIX_DIM_OFF);
75
76 writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF);
77
78 return 0;
79 }
80
keyscan_stop(struct st_keyscan * keypad)81 static void keyscan_stop(struct st_keyscan *keypad)
82 {
83 writel(0, keypad->base + KEYSCAN_CONFIG_OFF);
84
85 clk_disable(keypad->clk);
86 }
87
keyscan_open(struct input_dev * dev)88 static int keyscan_open(struct input_dev *dev)
89 {
90 struct st_keyscan *keypad = input_get_drvdata(dev);
91
92 return keyscan_start(keypad);
93 }
94
keyscan_close(struct input_dev * dev)95 static void keyscan_close(struct input_dev *dev)
96 {
97 struct st_keyscan *keypad = input_get_drvdata(dev);
98
99 keyscan_stop(keypad);
100 }
101
keypad_matrix_key_parse_dt(struct st_keyscan * keypad_data)102 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data)
103 {
104 struct device *dev = keypad_data->input_dev->dev.parent;
105 struct device_node *np = dev->of_node;
106 int error;
107
108 error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows,
109 &keypad_data->n_cols);
110 if (error) {
111 dev_err(dev, "failed to parse keypad params\n");
112 return error;
113 }
114
115 of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us);
116
117 dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n",
118 keypad_data->n_rows, keypad_data->n_cols,
119 keypad_data->debounce_us);
120
121 return 0;
122 }
123
keyscan_probe(struct platform_device * pdev)124 static int keyscan_probe(struct platform_device *pdev)
125 {
126 struct st_keyscan *keypad_data;
127 struct input_dev *input_dev;
128 struct resource *res;
129 int error;
130
131 if (!pdev->dev.of_node) {
132 dev_err(&pdev->dev, "no DT data present\n");
133 return -EINVAL;
134 }
135
136 keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data),
137 GFP_KERNEL);
138 if (!keypad_data)
139 return -ENOMEM;
140
141 input_dev = devm_input_allocate_device(&pdev->dev);
142 if (!input_dev) {
143 dev_err(&pdev->dev, "failed to allocate the input device\n");
144 return -ENOMEM;
145 }
146
147 input_dev->name = pdev->name;
148 input_dev->phys = "keyscan-keys/input0";
149 input_dev->dev.parent = &pdev->dev;
150 input_dev->open = keyscan_open;
151 input_dev->close = keyscan_close;
152
153 input_dev->id.bustype = BUS_HOST;
154
155 keypad_data->input_dev = input_dev;
156
157 error = keypad_matrix_key_parse_dt(keypad_data);
158 if (error)
159 return error;
160
161 error = matrix_keypad_build_keymap(NULL, NULL,
162 keypad_data->n_rows,
163 keypad_data->n_cols,
164 NULL, input_dev);
165 if (error) {
166 dev_err(&pdev->dev, "failed to build keymap\n");
167 return error;
168 }
169
170 input_set_drvdata(input_dev, keypad_data);
171
172 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
173 keypad_data->base = devm_ioremap_resource(&pdev->dev, res);
174 if (IS_ERR(keypad_data->base))
175 return PTR_ERR(keypad_data->base);
176
177 keypad_data->clk = devm_clk_get(&pdev->dev, NULL);
178 if (IS_ERR(keypad_data->clk)) {
179 dev_err(&pdev->dev, "cannot get clock\n");
180 return PTR_ERR(keypad_data->clk);
181 }
182
183 error = clk_enable(keypad_data->clk);
184 if (error) {
185 dev_err(&pdev->dev, "failed to enable clock\n");
186 return error;
187 }
188
189 keyscan_stop(keypad_data);
190
191 keypad_data->irq = platform_get_irq(pdev, 0);
192 if (keypad_data->irq < 0)
193 return -EINVAL;
194
195 error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0,
196 pdev->name, keypad_data);
197 if (error) {
198 dev_err(&pdev->dev, "failed to request IRQ\n");
199 return error;
200 }
201
202 error = input_register_device(input_dev);
203 if (error) {
204 dev_err(&pdev->dev, "failed to register input device\n");
205 return error;
206 }
207
208 platform_set_drvdata(pdev, keypad_data);
209
210 device_set_wakeup_capable(&pdev->dev, 1);
211
212 return 0;
213 }
214
215 #ifdef CONFIG_PM_SLEEP
keyscan_suspend(struct device * dev)216 static int keyscan_suspend(struct device *dev)
217 {
218 struct platform_device *pdev = to_platform_device(dev);
219 struct st_keyscan *keypad = platform_get_drvdata(pdev);
220 struct input_dev *input = keypad->input_dev;
221
222 mutex_lock(&input->mutex);
223
224 if (device_may_wakeup(dev))
225 enable_irq_wake(keypad->irq);
226 else if (input_device_enabled(input))
227 keyscan_stop(keypad);
228
229 mutex_unlock(&input->mutex);
230 return 0;
231 }
232
keyscan_resume(struct device * dev)233 static int keyscan_resume(struct device *dev)
234 {
235 struct platform_device *pdev = to_platform_device(dev);
236 struct st_keyscan *keypad = platform_get_drvdata(pdev);
237 struct input_dev *input = keypad->input_dev;
238 int retval = 0;
239
240 mutex_lock(&input->mutex);
241
242 if (device_may_wakeup(dev))
243 disable_irq_wake(keypad->irq);
244 else if (input_device_enabled(input))
245 retval = keyscan_start(keypad);
246
247 mutex_unlock(&input->mutex);
248 return retval;
249 }
250 #endif
251
252 static SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, keyscan_suspend, keyscan_resume);
253
254 static const struct of_device_id keyscan_of_match[] = {
255 { .compatible = "st,sti-keyscan" },
256 { },
257 };
258 MODULE_DEVICE_TABLE(of, keyscan_of_match);
259
260 static struct platform_driver keyscan_device_driver = {
261 .probe = keyscan_probe,
262 .driver = {
263 .name = "st-keyscan",
264 .pm = &keyscan_dev_pm_ops,
265 .of_match_table = of_match_ptr(keyscan_of_match),
266 }
267 };
268
269 module_platform_driver(keyscan_device_driver);
270
271 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>");
272 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver");
273 MODULE_LICENSE("GPL");
274
