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