1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for the Cirrus EP93xx matrix keypad controller.
4  *
5  * Copyright (c) 2008 H Hartley Sweeten <hsweeten@visionengravers.com>
6  *
7  * Based on the pxa27x matrix keypad controller by Rodolfo Giometti.
8  *
9  * NOTE:
10  *
11  * The 3-key reset is triggered by pressing the 3 keys in
12  * Row 0, Columns 2, 4, and 7 at the same time.  This action can
13  * be disabled by setting the EP93XX_KEYPAD_DISABLE_3_KEY flag.
14  *
15  * Normal operation for the matrix does not autorepeat the key press.
16  * This action can be enabled by setting the EP93XX_KEYPAD_AUTOREPEAT
17  * flag.
18  */
19 
20 #include <linux/bits.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include <linux/interrupt.h>
24 #include <linux/clk.h>
25 #include <linux/io.h>
26 #include <linux/input.h>
27 #include <linux/input/matrix_keypad.h>
28 #include <linux/slab.h>
29 #include <linux/soc/cirrus/ep93xx.h>
30 #include <linux/platform_data/keypad-ep93xx.h>
31 #include <linux/pm_wakeirq.h>
32 
33 /*
34  * Keypad Interface Register offsets
35  */
36 #define KEY_INIT		0x00	/* Key Scan Initialization register */
37 #define KEY_DIAG		0x04	/* Key Scan Diagnostic register */
38 #define KEY_REG			0x08	/* Key Value Capture register */
39 
40 /* Key Scan Initialization Register bit defines */
41 #define KEY_INIT_DBNC_MASK	GENMASK(23, 16)
42 #define KEY_INIT_DBNC_SHIFT	16
43 #define KEY_INIT_DIS3KY		BIT(15)
44 #define KEY_INIT_DIAG		BIT(14)
45 #define KEY_INIT_BACK		BIT(13)
46 #define KEY_INIT_T2		BIT(12)
47 #define KEY_INIT_PRSCL_MASK	GENMASK(9, 0)
48 #define KEY_INIT_PRSCL_SHIFT	0
49 
50 /* Key Scan Diagnostic Register bit defines */
51 #define KEY_DIAG_MASK		GENMASK(5, 0)
52 #define KEY_DIAG_SHIFT		0
53 
54 /* Key Value Capture Register bit defines */
55 #define KEY_REG_K		BIT(15)
56 #define KEY_REG_INT		BIT(14)
57 #define KEY_REG_2KEYS		BIT(13)
58 #define KEY_REG_1KEY		BIT(12)
59 #define KEY_REG_KEY2_MASK	GENMASK(11, 6)
60 #define KEY_REG_KEY2_SHIFT	6
61 #define KEY_REG_KEY1_MASK	GENMASK(5, 0)
62 #define KEY_REG_KEY1_SHIFT	0
63 
64 #define EP93XX_MATRIX_SIZE	(EP93XX_MATRIX_ROWS * EP93XX_MATRIX_COLS)
65 
66 struct ep93xx_keypad {
67 	struct ep93xx_keypad_platform_data *pdata;
68 	struct input_dev *input_dev;
69 	struct clk *clk;
70 
71 	void __iomem *mmio_base;
72 
73 	unsigned short keycodes[EP93XX_MATRIX_SIZE];
74 
75 	int key1;
76 	int key2;
77 
78 	int irq;
79 
80 	bool enabled;
81 };
82 
83 static irqreturn_t ep93xx_keypad_irq_handler(int irq, void *dev_id)
84 {
85 	struct ep93xx_keypad *keypad = dev_id;
86 	struct input_dev *input_dev = keypad->input_dev;
87 	unsigned int status;
88 	int keycode, key1, key2;
89 
90 	status = __raw_readl(keypad->mmio_base + KEY_REG);
91 
92 	keycode = (status & KEY_REG_KEY1_MASK) >> KEY_REG_KEY1_SHIFT;
93 	key1 = keypad->keycodes[keycode];
94 
95 	keycode = (status & KEY_REG_KEY2_MASK) >> KEY_REG_KEY2_SHIFT;
96 	key2 = keypad->keycodes[keycode];
97 
98 	if (status & KEY_REG_2KEYS) {
99 		if (keypad->key1 && key1 != keypad->key1 && key2 != keypad->key1)
100 			input_report_key(input_dev, keypad->key1, 0);
101 
102 		if (keypad->key2 && key1 != keypad->key2 && key2 != keypad->key2)
103 			input_report_key(input_dev, keypad->key2, 0);
104 
105 		input_report_key(input_dev, key1, 1);
106 		input_report_key(input_dev, key2, 1);
107 
108 		keypad->key1 = key1;
109 		keypad->key2 = key2;
110 
111 	} else if (status & KEY_REG_1KEY) {
112 		if (keypad->key1 && key1 != keypad->key1)
113 			input_report_key(input_dev, keypad->key1, 0);
114 
115 		if (keypad->key2 && key1 != keypad->key2)
116 			input_report_key(input_dev, keypad->key2, 0);
117 
118 		input_report_key(input_dev, key1, 1);
119 
120 		keypad->key1 = key1;
121 		keypad->key2 = 0;
122 
123 	} else {
124 		input_report_key(input_dev, keypad->key1, 0);
125 		input_report_key(input_dev, keypad->key2, 0);
126 
127 		keypad->key1 = keypad->key2 = 0;
128 	}
129 	input_sync(input_dev);
130 
131 	return IRQ_HANDLED;
132 }
133 
134 static void ep93xx_keypad_config(struct ep93xx_keypad *keypad)
135 {
136 	struct ep93xx_keypad_platform_data *pdata = keypad->pdata;
137 	unsigned int val = 0;
138 
139 	clk_set_rate(keypad->clk, pdata->clk_rate);
140 
141 	if (pdata->flags & EP93XX_KEYPAD_DISABLE_3_KEY)
142 		val |= KEY_INIT_DIS3KY;
143 	if (pdata->flags & EP93XX_KEYPAD_DIAG_MODE)
144 		val |= KEY_INIT_DIAG;
145 	if (pdata->flags & EP93XX_KEYPAD_BACK_DRIVE)
146 		val |= KEY_INIT_BACK;
147 	if (pdata->flags & EP93XX_KEYPAD_TEST_MODE)
148 		val |= KEY_INIT_T2;
149 
150 	val |= ((pdata->debounce << KEY_INIT_DBNC_SHIFT) & KEY_INIT_DBNC_MASK);
151 
152 	val |= ((pdata->prescale << KEY_INIT_PRSCL_SHIFT) & KEY_INIT_PRSCL_MASK);
153 
154 	__raw_writel(val, keypad->mmio_base + KEY_INIT);
155 }
156 
157 static int ep93xx_keypad_open(struct input_dev *pdev)
158 {
159 	struct ep93xx_keypad *keypad = input_get_drvdata(pdev);
160 
161 	if (!keypad->enabled) {
162 		ep93xx_keypad_config(keypad);
163 		clk_prepare_enable(keypad->clk);
164 		keypad->enabled = true;
165 	}
166 
167 	return 0;
168 }
169 
170 static void ep93xx_keypad_close(struct input_dev *pdev)
171 {
172 	struct ep93xx_keypad *keypad = input_get_drvdata(pdev);
173 
174 	if (keypad->enabled) {
175 		clk_disable_unprepare(keypad->clk);
176 		keypad->enabled = false;
177 	}
178 }
179 
180 
181 static int __maybe_unused ep93xx_keypad_suspend(struct device *dev)
182 {
183 	struct platform_device *pdev = to_platform_device(dev);
184 	struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
185 	struct input_dev *input_dev = keypad->input_dev;
186 
187 	mutex_lock(&input_dev->mutex);
188 
189 	if (keypad->enabled) {
190 		clk_disable(keypad->clk);
191 		keypad->enabled = false;
192 	}
193 
194 	mutex_unlock(&input_dev->mutex);
195 
196 	return 0;
197 }
198 
199 static int __maybe_unused ep93xx_keypad_resume(struct device *dev)
200 {
201 	struct platform_device *pdev = to_platform_device(dev);
202 	struct ep93xx_keypad *keypad = platform_get_drvdata(pdev);
203 	struct input_dev *input_dev = keypad->input_dev;
204 
205 	mutex_lock(&input_dev->mutex);
206 
207 	if (input_device_enabled(input_dev)) {
208 		if (!keypad->enabled) {
209 			ep93xx_keypad_config(keypad);
210 			clk_enable(keypad->clk);
211 			keypad->enabled = true;
212 		}
213 	}
214 
215 	mutex_unlock(&input_dev->mutex);
216 
217 	return 0;
218 }
219 
220 static SIMPLE_DEV_PM_OPS(ep93xx_keypad_pm_ops,
221 			 ep93xx_keypad_suspend, ep93xx_keypad_resume);
222 
223 static void ep93xx_keypad_release_gpio_action(void *_pdev)
224 {
225 	struct platform_device *pdev = _pdev;
226 
227 	ep93xx_keypad_release_gpio(pdev);
228 }
229 
230 static int ep93xx_keypad_probe(struct platform_device *pdev)
231 {
232 	struct ep93xx_keypad *keypad;
233 	const struct matrix_keymap_data *keymap_data;
234 	struct input_dev *input_dev;
235 	int err;
236 
237 	keypad = devm_kzalloc(&pdev->dev, sizeof(*keypad), GFP_KERNEL);
238 	if (!keypad)
239 		return -ENOMEM;
240 
241 	keypad->pdata = dev_get_platdata(&pdev->dev);
242 	if (!keypad->pdata)
243 		return -EINVAL;
244 
245 	keymap_data = keypad->pdata->keymap_data;
246 	if (!keymap_data)
247 		return -EINVAL;
248 
249 	keypad->irq = platform_get_irq(pdev, 0);
250 	if (keypad->irq < 0)
251 		return keypad->irq;
252 
253 	keypad->mmio_base = devm_platform_ioremap_resource(pdev, 0);
254 	if (IS_ERR(keypad->mmio_base))
255 		return PTR_ERR(keypad->mmio_base);
256 
257 	err = ep93xx_keypad_acquire_gpio(pdev);
258 	if (err)
259 		return err;
260 
261 	err = devm_add_action_or_reset(&pdev->dev,
262 				       ep93xx_keypad_release_gpio_action, pdev);
263 	if (err)
264 		return err;
265 
266 	keypad->clk = devm_clk_get(&pdev->dev, NULL);
267 	if (IS_ERR(keypad->clk))
268 		return PTR_ERR(keypad->clk);
269 
270 	input_dev = devm_input_allocate_device(&pdev->dev);
271 	if (!input_dev)
272 		return -ENOMEM;
273 
274 	keypad->input_dev = input_dev;
275 
276 	input_dev->name = pdev->name;
277 	input_dev->id.bustype = BUS_HOST;
278 	input_dev->open = ep93xx_keypad_open;
279 	input_dev->close = ep93xx_keypad_close;
280 
281 	err = matrix_keypad_build_keymap(keymap_data, NULL,
282 					 EP93XX_MATRIX_ROWS, EP93XX_MATRIX_COLS,
283 					 keypad->keycodes, input_dev);
284 	if (err)
285 		return err;
286 
287 	if (keypad->pdata->flags & EP93XX_KEYPAD_AUTOREPEAT)
288 		__set_bit(EV_REP, input_dev->evbit);
289 	input_set_drvdata(input_dev, keypad);
290 
291 	err = devm_request_irq(&pdev->dev, keypad->irq,
292 			       ep93xx_keypad_irq_handler,
293 			       0, pdev->name, keypad);
294 	if (err)
295 		return err;
296 
297 	err = input_register_device(input_dev);
298 	if (err)
299 		return err;
300 
301 	platform_set_drvdata(pdev, keypad);
302 
303 	device_init_wakeup(&pdev->dev, 1);
304 	err = dev_pm_set_wake_irq(&pdev->dev, keypad->irq);
305 	if (err)
306 		dev_warn(&pdev->dev, "failed to set up wakeup irq: %d\n", err);
307 
308 	return 0;
309 }
310 
311 static int ep93xx_keypad_remove(struct platform_device *pdev)
312 {
313 	dev_pm_clear_wake_irq(&pdev->dev);
314 
315 	return 0;
316 }
317 
318 static struct platform_driver ep93xx_keypad_driver = {
319 	.driver		= {
320 		.name	= "ep93xx-keypad",
321 		.pm	= &ep93xx_keypad_pm_ops,
322 	},
323 	.probe		= ep93xx_keypad_probe,
324 	.remove		= ep93xx_keypad_remove,
325 };
326 module_platform_driver(ep93xx_keypad_driver);
327 
328 MODULE_LICENSE("GPL");
329 MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
330 MODULE_DESCRIPTION("EP93xx Matrix Keypad Controller");
331 MODULE_ALIAS("platform:ep93xx-keypad");
332