xref: /linux/drivers/input/keyboard/spear-keyboard.c (revision d2a4a07190f42e4f82805daf58e708400b703f1c) 
1 /*
2  * SPEAr Keyboard Driver
3  * Based on omap-keypad driver
4  *
5  * Copyright (C) 2010 ST Microelectronics
6  * Rajeev Kumar <rajeevkumar.linux@gmail.com>
7  *
8  * This file is licensed under the terms of the GNU General Public
9  * License version 2. This program is licensed "as is" without any
10  * warranty of any kind, whether express or implied.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/errno.h>
15 #include <linux/interrupt.h>
16 #include <linux/input.h>
17 #include <linux/io.h>
18 #include <linux/irq.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/pm_wakeup.h>
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/platform_data/keyboard-spear.h>
27 
28 /* Keyboard Registers */
29 #define MODE_CTL_REG	0x00
30 #define STATUS_REG	0x0C
31 #define DATA_REG	0x10
32 #define INTR_MASK	0x54
33 
34 /* Register Values */
35 #define NUM_ROWS	16
36 #define NUM_COLS	16
37 #define MODE_CTL_PCLK_FREQ_SHIFT	9
38 #define MODE_CTL_PCLK_FREQ_MSK		0x7F
39 
40 #define MODE_CTL_KEYBOARD	(0x2 << 0)
41 #define MODE_CTL_SCAN_RATE_10	(0x0 << 2)
42 #define MODE_CTL_SCAN_RATE_20	(0x1 << 2)
43 #define MODE_CTL_SCAN_RATE_40	(0x2 << 2)
44 #define MODE_CTL_SCAN_RATE_80	(0x3 << 2)
45 #define MODE_CTL_KEYNUM_SHIFT	6
46 #define MODE_CTL_START_SCAN	(0x1 << 8)
47 
48 #define STATUS_DATA_AVAIL	(0x1 << 1)
49 
50 #define DATA_ROW_MASK		0xF0
51 #define DATA_COLUMN_MASK	0x0F
52 
53 #define ROW_SHIFT		4
54 
55 struct spear_kbd {
56 	struct input_dev *input;
57 	void __iomem *io_base;
58 	struct clk *clk;
59 	unsigned int irq;
60 	unsigned int mode;
61 	unsigned int suspended_rate;
62 	unsigned short last_key;
63 	unsigned short keycodes[NUM_ROWS * NUM_COLS];
64 	bool rep;
65 	bool irq_wake_enabled;
66 	u32 mode_ctl_reg;
67 };
68 
69 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
70 {
71 	struct spear_kbd *kbd = dev_id;
72 	struct input_dev *input = kbd->input;
73 	unsigned int key;
74 	u32 sts, val;
75 
76 	sts = readl_relaxed(kbd->io_base + STATUS_REG);
77 	if (!(sts & STATUS_DATA_AVAIL))
78 		return IRQ_NONE;
79 
80 	if (kbd->last_key != KEY_RESERVED) {
81 		input_report_key(input, kbd->last_key, 0);
82 		kbd->last_key = KEY_RESERVED;
83 	}
84 
85 	/* following reads active (row, col) pair */
86 	val = readl_relaxed(kbd->io_base + DATA_REG) &
87 		(DATA_ROW_MASK | DATA_COLUMN_MASK);
88 	key = kbd->keycodes[val];
89 
90 	input_event(input, EV_MSC, MSC_SCAN, val);
91 	input_report_key(input, key, 1);
92 	input_sync(input);
93 
94 	kbd->last_key = key;
95 
96 	/* clear interrupt */
97 	writel_relaxed(0, kbd->io_base + STATUS_REG);
98 
99 	return IRQ_HANDLED;
100 }
101 
102 static int spear_kbd_open(struct input_dev *dev)
103 {
104 	struct spear_kbd *kbd = input_get_drvdata(dev);
105 	int error;
106 	u32 val;
107 
108 	kbd->last_key = KEY_RESERVED;
109 
110 	error = clk_enable(kbd->clk);
111 	if (error)
112 		return error;
113 
114 	/* keyboard rate to be programmed is input clock (in MHz) - 1 */
115 	val = clk_get_rate(kbd->clk) / 1000000 - 1;
116 	val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
117 
118 	/* program keyboard */
119 	val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
120 		(kbd->mode << MODE_CTL_KEYNUM_SHIFT);
121 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
122 	writel_relaxed(1, kbd->io_base + STATUS_REG);
123 
124 	/* start key scan */
125 	val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
126 	val |= MODE_CTL_START_SCAN;
127 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
128 
129 	return 0;
130 }
131 
132 static void spear_kbd_close(struct input_dev *dev)
133 {
134 	struct spear_kbd *kbd = input_get_drvdata(dev);
135 	u32 val;
136 
137 	/* stop key scan */
138 	val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
139 	val &= ~MODE_CTL_START_SCAN;
140 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
141 
142 	clk_disable(kbd->clk);
143 
144 	kbd->last_key = KEY_RESERVED;
145 }
146 
147 #ifdef CONFIG_OF
148 static int spear_kbd_parse_dt(struct platform_device *pdev,
149                                         struct spear_kbd *kbd)
150 {
151 	struct device_node *np = pdev->dev.of_node;
152 	int error;
153 	u32 val, suspended_rate;
154 
155 	if (!np) {
156 		dev_err(&pdev->dev, "Missing DT data\n");
157 		return -EINVAL;
158 	}
159 
160 	if (of_property_read_bool(np, "autorepeat"))
161 		kbd->rep = true;
162 
163 	if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
164 		kbd->suspended_rate = suspended_rate;
165 
166 	error = of_property_read_u32(np, "st,mode", &val);
167 	if (error) {
168 		dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
169 		return error;
170 	}
171 
172 	kbd->mode = val;
173 	return 0;
174 }
175 #else
176 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
177 				     struct spear_kbd *kbd)
178 {
179 	return -ENOSYS;
180 }
181 #endif
182 
183 static int spear_kbd_probe(struct platform_device *pdev)
184 {
185 	struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
186 	const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
187 	struct spear_kbd *kbd;
188 	struct input_dev *input_dev;
189 	int irq;
190 	int error;
191 
192 	irq = platform_get_irq(pdev, 0);
193 	if (irq < 0)
194 		return irq;
195 
196 	kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
197 	if (!kbd) {
198 		dev_err(&pdev->dev, "not enough memory for driver data\n");
199 		return -ENOMEM;
200 	}
201 
202 	input_dev = devm_input_allocate_device(&pdev->dev);
203 	if (!input_dev) {
204 		dev_err(&pdev->dev, "unable to allocate input device\n");
205 		return -ENOMEM;
206 	}
207 
208 	kbd->input = input_dev;
209 	kbd->irq = irq;
210 
211 	if (!pdata) {
212 		error = spear_kbd_parse_dt(pdev, kbd);
213 		if (error)
214 			return error;
215 	} else {
216 		kbd->mode = pdata->mode;
217 		kbd->rep = pdata->rep;
218 		kbd->suspended_rate = pdata->suspended_rate;
219 	}
220 
221 	kbd->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
222 	if (IS_ERR(kbd->io_base))
223 		return PTR_ERR(kbd->io_base);
224 
225 	kbd->clk = devm_clk_get(&pdev->dev, NULL);
226 	if (IS_ERR(kbd->clk))
227 		return PTR_ERR(kbd->clk);
228 
229 	input_dev->name = "Spear Keyboard";
230 	input_dev->phys = "keyboard/input0";
231 	input_dev->id.bustype = BUS_HOST;
232 	input_dev->id.vendor = 0x0001;
233 	input_dev->id.product = 0x0001;
234 	input_dev->id.version = 0x0100;
235 	input_dev->open = spear_kbd_open;
236 	input_dev->close = spear_kbd_close;
237 
238 	error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
239 					   kbd->keycodes, input_dev);
240 	if (error) {
241 		dev_err(&pdev->dev, "Failed to build keymap\n");
242 		return error;
243 	}
244 
245 	if (kbd->rep)
246 		__set_bit(EV_REP, input_dev->evbit);
247 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
248 
249 	input_set_drvdata(input_dev, kbd);
250 
251 	error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
252 			"keyboard", kbd);
253 	if (error) {
254 		dev_err(&pdev->dev, "request_irq failed\n");
255 		return error;
256 	}
257 
258 	error = clk_prepare(kbd->clk);
259 	if (error)
260 		return error;
261 
262 	error = input_register_device(input_dev);
263 	if (error) {
264 		dev_err(&pdev->dev, "Unable to register keyboard device\n");
265 		clk_unprepare(kbd->clk);
266 		return error;
267 	}
268 
269 	device_init_wakeup(&pdev->dev, 1);
270 	platform_set_drvdata(pdev, kbd);
271 
272 	return 0;
273 }
274 
275 static void spear_kbd_remove(struct platform_device *pdev)
276 {
277 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
278 
279 	input_unregister_device(kbd->input);
280 	clk_unprepare(kbd->clk);
281 }
282 
283 static int spear_kbd_suspend(struct device *dev)
284 {
285 	struct platform_device *pdev = to_platform_device(dev);
286 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
287 	struct input_dev *input_dev = kbd->input;
288 	unsigned int rate = 0, mode_ctl_reg, val;
289 
290 	mutex_lock(&input_dev->mutex);
291 
292 	/* explicitly enable clock as we may program device */
293 	clk_enable(kbd->clk);
294 
295 	mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
296 
297 	if (device_may_wakeup(&pdev->dev)) {
298 		if (!enable_irq_wake(kbd->irq))
299 			kbd->irq_wake_enabled = true;
300 
301 		/*
302 		 * reprogram the keyboard operating frequency as on some
303 		 * platform it may change during system suspended
304 		 */
305 		if (kbd->suspended_rate)
306 			rate = kbd->suspended_rate / 1000000 - 1;
307 		else
308 			rate = clk_get_rate(kbd->clk) / 1000000 - 1;
309 
310 		val = mode_ctl_reg &
311 			~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
312 		val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
313 			<< MODE_CTL_PCLK_FREQ_SHIFT;
314 		writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
315 
316 	} else {
317 		if (input_device_enabled(input_dev)) {
318 			writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
319 					kbd->io_base + MODE_CTL_REG);
320 			clk_disable(kbd->clk);
321 		}
322 	}
323 
324 	/* store current configuration */
325 	if (input_device_enabled(input_dev))
326 		kbd->mode_ctl_reg = mode_ctl_reg;
327 
328 	/* restore previous clk state */
329 	clk_disable(kbd->clk);
330 
331 	mutex_unlock(&input_dev->mutex);
332 
333 	return 0;
334 }
335 
336 static int spear_kbd_resume(struct device *dev)
337 {
338 	struct platform_device *pdev = to_platform_device(dev);
339 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
340 	struct input_dev *input_dev = kbd->input;
341 
342 	mutex_lock(&input_dev->mutex);
343 
344 	if (device_may_wakeup(&pdev->dev)) {
345 		if (kbd->irq_wake_enabled) {
346 			kbd->irq_wake_enabled = false;
347 			disable_irq_wake(kbd->irq);
348 		}
349 	} else {
350 		if (input_device_enabled(input_dev))
351 			clk_enable(kbd->clk);
352 	}
353 
354 	/* restore current configuration */
355 	if (input_device_enabled(input_dev))
356 		writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
357 
358 	mutex_unlock(&input_dev->mutex);
359 
360 	return 0;
361 }
362 
363 static DEFINE_SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops,
364 				spear_kbd_suspend, spear_kbd_resume);
365 
366 #ifdef CONFIG_OF
367 static const struct of_device_id spear_kbd_id_table[] = {
368 	{ .compatible = "st,spear300-kbd" },
369 	{}
370 };
371 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
372 #endif
373 
374 static struct platform_driver spear_kbd_driver = {
375 	.probe		= spear_kbd_probe,
376 	.remove_new	= spear_kbd_remove,
377 	.driver		= {
378 		.name	= "keyboard",
379 		.pm	= pm_sleep_ptr(&spear_kbd_pm_ops),
380 		.of_match_table = of_match_ptr(spear_kbd_id_table),
381 	},
382 };
383 module_platform_driver(spear_kbd_driver);
384 
385 MODULE_AUTHOR("Rajeev Kumar");
386 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
387 MODULE_LICENSE("GPL");
388