2 * STMicroelectronics Key Scanning driver
4 * Copyright (c) 2014 STMicroelectonics Ltd.
5 * Author: Stuart Menefy <stuart.menefy@st.com>
7 * Based on sh_keysc.c, copyright 2008 Magnus Damm
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/module.h>
15 #include <linux/interrupt.h>
16 #include <linux/platform_device.h>
17 #include <linux/clk.h>
19 #include <linux/input/matrix_keypad.h>
21 #define ST_KEYSCAN_MAXKEYS 16
23 #define KEYSCAN_CONFIG_OFF 0x0
24 #define KEYSCAN_CONFIG_ENABLE 0x1
25 #define KEYSCAN_DEBOUNCE_TIME_OFF 0x4
26 #define KEYSCAN_MATRIX_STATE_OFF 0x8
27 #define KEYSCAN_MATRIX_DIM_OFF 0xc
28 #define KEYSCAN_MATRIX_DIM_X_SHIFT 0x0
29 #define KEYSCAN_MATRIX_DIM_Y_SHIFT 0x2
35 struct input_dev *input_dev;
36 unsigned long last_state;
39 unsigned int debounce_us;
42 static irqreturn_t keyscan_isr(int irq, void *dev_id)
44 struct st_keyscan *keypad = dev_id;
45 unsigned short *keycode = keypad->input_dev->keycode;
46 unsigned long state, change;
49 state = readl(keypad->base + KEYSCAN_MATRIX_STATE_OFF) & 0xffff;
50 change = keypad->last_state ^ state;
51 keypad->last_state = state;
53 for_each_set_bit(bit_nr, &change, BITS_PER_LONG)
54 input_report_key(keypad->input_dev,
55 keycode[bit_nr], state & BIT(bit_nr));
57 input_sync(keypad->input_dev);
62 static int keyscan_start(struct st_keyscan *keypad)
66 error = clk_enable(keypad->clk);
70 writel(keypad->debounce_us * (clk_get_rate(keypad->clk) / 1000000),
71 keypad->base + KEYSCAN_DEBOUNCE_TIME_OFF);
73 writel(((keypad->n_cols - 1) << KEYSCAN_MATRIX_DIM_X_SHIFT) |
74 ((keypad->n_rows - 1) << KEYSCAN_MATRIX_DIM_Y_SHIFT),
75 keypad->base + KEYSCAN_MATRIX_DIM_OFF);
77 writel(KEYSCAN_CONFIG_ENABLE, keypad->base + KEYSCAN_CONFIG_OFF);
82 static void keyscan_stop(struct st_keyscan *keypad)
84 writel(0, keypad->base + KEYSCAN_CONFIG_OFF);
86 clk_disable(keypad->clk);
89 static int keyscan_open(struct input_dev *dev)
91 struct st_keyscan *keypad = input_get_drvdata(dev);
93 return keyscan_start(keypad);
96 static void keyscan_close(struct input_dev *dev)
98 struct st_keyscan *keypad = input_get_drvdata(dev);
100 keyscan_stop(keypad);
103 static int keypad_matrix_key_parse_dt(struct st_keyscan *keypad_data)
105 struct device *dev = keypad_data->input_dev->dev.parent;
106 struct device_node *np = dev->of_node;
109 error = matrix_keypad_parse_properties(dev, &keypad_data->n_rows,
110 &keypad_data->n_cols);
112 dev_err(dev, "failed to parse keypad params\n");
116 of_property_read_u32(np, "st,debounce-us", &keypad_data->debounce_us);
118 dev_dbg(dev, "n_rows=%d n_col=%d debounce=%d\n",
119 keypad_data->n_rows, keypad_data->n_cols,
120 keypad_data->debounce_us);
125 static int keyscan_probe(struct platform_device *pdev)
127 struct st_keyscan *keypad_data;
128 struct input_dev *input_dev;
129 struct resource *res;
132 if (!pdev->dev.of_node) {
133 dev_err(&pdev->dev, "no DT data present\n");
137 keypad_data = devm_kzalloc(&pdev->dev, sizeof(*keypad_data),
142 input_dev = devm_input_allocate_device(&pdev->dev);
144 dev_err(&pdev->dev, "failed to allocate the input device\n");
148 input_dev->name = pdev->name;
149 input_dev->phys = "keyscan-keys/input0";
150 input_dev->dev.parent = &pdev->dev;
151 input_dev->open = keyscan_open;
152 input_dev->close = keyscan_close;
154 input_dev->id.bustype = BUS_HOST;
156 error = keypad_matrix_key_parse_dt(keypad_data);
160 error = matrix_keypad_build_keymap(NULL, NULL,
165 dev_err(&pdev->dev, "failed to build keymap\n");
169 input_set_drvdata(input_dev, keypad_data);
171 keypad_data->input_dev = input_dev;
173 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
174 keypad_data->base = devm_ioremap_resource(&pdev->dev, res);
175 if (IS_ERR(keypad_data->base))
176 return PTR_ERR(keypad_data->base);
178 keypad_data->clk = devm_clk_get(&pdev->dev, NULL);
179 if (IS_ERR(keypad_data->clk)) {
180 dev_err(&pdev->dev, "cannot get clock\n");
181 return PTR_ERR(keypad_data->clk);
184 error = clk_enable(keypad_data->clk);
186 dev_err(&pdev->dev, "failed to enable clock\n");
190 keyscan_stop(keypad_data);
192 keypad_data->irq = platform_get_irq(pdev, 0);
193 if (keypad_data->irq < 0) {
194 dev_err(&pdev->dev, "no IRQ specified\n");
198 error = devm_request_irq(&pdev->dev, keypad_data->irq, keyscan_isr, 0,
199 pdev->name, keypad_data);
201 dev_err(&pdev->dev, "failed to request IRQ\n");
205 error = input_register_device(input_dev);
207 dev_err(&pdev->dev, "failed to register input device\n");
211 platform_set_drvdata(pdev, keypad_data);
213 device_set_wakeup_capable(&pdev->dev, 1);
218 #ifdef CONFIG_PM_SLEEP
219 static int keyscan_suspend(struct device *dev)
221 struct platform_device *pdev = to_platform_device(dev);
222 struct st_keyscan *keypad = platform_get_drvdata(pdev);
223 struct input_dev *input = keypad->input_dev;
225 mutex_lock(&input->mutex);
227 if (device_may_wakeup(dev))
228 enable_irq_wake(keypad->irq);
229 else if (input->users)
230 keyscan_stop(keypad);
232 mutex_unlock(&input->mutex);
236 static int keyscan_resume(struct device *dev)
238 struct platform_device *pdev = to_platform_device(dev);
239 struct st_keyscan *keypad = platform_get_drvdata(pdev);
240 struct input_dev *input = keypad->input_dev;
243 mutex_lock(&input->mutex);
245 if (device_may_wakeup(dev))
246 disable_irq_wake(keypad->irq);
247 else if (input->users)
248 retval = keyscan_start(keypad);
250 mutex_unlock(&input->mutex);
255 static SIMPLE_DEV_PM_OPS(keyscan_dev_pm_ops, keyscan_suspend, keyscan_resume);
257 static const struct of_device_id keyscan_of_match[] = {
258 { .compatible = "st,sti-keyscan" },
261 MODULE_DEVICE_TABLE(of, keyscan_of_match);
263 static struct platform_driver keyscan_device_driver = {
264 .probe = keyscan_probe,
266 .name = "st-keyscan",
267 .pm = &keyscan_dev_pm_ops,
268 .of_match_table = of_match_ptr(keyscan_of_match),
272 module_platform_driver(keyscan_device_driver);
274 MODULE_AUTHOR("Stuart Menefy <stuart.menefy@st.com>");
275 MODULE_DESCRIPTION("STMicroelectronics keyscan device driver");
276 MODULE_LICENSE("GPL");