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 	struct resource *res;
190 	int irq;
191 	int error;
192 
193 	irq = platform_get_irq(pdev, 0);
194 	if (irq < 0) {
195 		dev_err(&pdev->dev, "not able to get irq for the device\n");
196 		return irq;
197 	}
198 
199 	kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
200 	if (!kbd) {
201 		dev_err(&pdev->dev, "not enough memory for driver data\n");
202 		return -ENOMEM;
203 	}
204 
205 	input_dev = devm_input_allocate_device(&pdev->dev);
206 	if (!input_dev) {
207 		dev_err(&pdev->dev, "unable to allocate input device\n");
208 		return -ENOMEM;
209 	}
210 
211 	kbd->input = input_dev;
212 	kbd->irq = irq;
213 
214 	if (!pdata) {
215 		error = spear_kbd_parse_dt(pdev, kbd);
216 		if (error)
217 			return error;
218 	} else {
219 		kbd->mode = pdata->mode;
220 		kbd->rep = pdata->rep;
221 		kbd->suspended_rate = pdata->suspended_rate;
222 	}
223 
224 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 	kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
226 	if (IS_ERR(kbd->io_base))
227 		return PTR_ERR(kbd->io_base);
228 
229 	kbd->clk = devm_clk_get(&pdev->dev, NULL);
230 	if (IS_ERR(kbd->clk))
231 		return PTR_ERR(kbd->clk);
232 
233 	input_dev->name = "Spear Keyboard";
234 	input_dev->phys = "keyboard/input0";
235 	input_dev->id.bustype = BUS_HOST;
236 	input_dev->id.vendor = 0x0001;
237 	input_dev->id.product = 0x0001;
238 	input_dev->id.version = 0x0100;
239 	input_dev->open = spear_kbd_open;
240 	input_dev->close = spear_kbd_close;
241 
242 	error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
243 					   kbd->keycodes, input_dev);
244 	if (error) {
245 		dev_err(&pdev->dev, "Failed to build keymap\n");
246 		return error;
247 	}
248 
249 	if (kbd->rep)
250 		__set_bit(EV_REP, input_dev->evbit);
251 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
252 
253 	input_set_drvdata(input_dev, kbd);
254 
255 	error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
256 			"keyboard", kbd);
257 	if (error) {
258 		dev_err(&pdev->dev, "request_irq failed\n");
259 		return error;
260 	}
261 
262 	error = clk_prepare(kbd->clk);
263 	if (error)
264 		return error;
265 
266 	error = input_register_device(input_dev);
267 	if (error) {
268 		dev_err(&pdev->dev, "Unable to register keyboard device\n");
269 		clk_unprepare(kbd->clk);
270 		return error;
271 	}
272 
273 	device_init_wakeup(&pdev->dev, 1);
274 	platform_set_drvdata(pdev, kbd);
275 
276 	return 0;
277 }
278 
279 static int spear_kbd_remove(struct platform_device *pdev)
280 {
281 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
282 
283 	input_unregister_device(kbd->input);
284 	clk_unprepare(kbd->clk);
285 
286 	return 0;
287 }
288 
289 static int __maybe_unused spear_kbd_suspend(struct device *dev)
290 {
291 	struct platform_device *pdev = to_platform_device(dev);
292 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
293 	struct input_dev *input_dev = kbd->input;
294 	unsigned int rate = 0, mode_ctl_reg, val;
295 
296 	mutex_lock(&input_dev->mutex);
297 
298 	/* explicitly enable clock as we may program device */
299 	clk_enable(kbd->clk);
300 
301 	mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
302 
303 	if (device_may_wakeup(&pdev->dev)) {
304 		if (!enable_irq_wake(kbd->irq))
305 			kbd->irq_wake_enabled = true;
306 
307 		/*
308 		 * reprogram the keyboard operating frequency as on some
309 		 * platform it may change during system suspended
310 		 */
311 		if (kbd->suspended_rate)
312 			rate = kbd->suspended_rate / 1000000 - 1;
313 		else
314 			rate = clk_get_rate(kbd->clk) / 1000000 - 1;
315 
316 		val = mode_ctl_reg &
317 			~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
318 		val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
319 			<< MODE_CTL_PCLK_FREQ_SHIFT;
320 		writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
321 
322 	} else {
323 		if (input_dev->users) {
324 			writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
325 					kbd->io_base + MODE_CTL_REG);
326 			clk_disable(kbd->clk);
327 		}
328 	}
329 
330 	/* store current configuration */
331 	if (input_dev->users)
332 		kbd->mode_ctl_reg = mode_ctl_reg;
333 
334 	/* restore previous clk state */
335 	clk_disable(kbd->clk);
336 
337 	mutex_unlock(&input_dev->mutex);
338 
339 	return 0;
340 }
341 
342 static int __maybe_unused spear_kbd_resume(struct device *dev)
343 {
344 	struct platform_device *pdev = to_platform_device(dev);
345 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
346 	struct input_dev *input_dev = kbd->input;
347 
348 	mutex_lock(&input_dev->mutex);
349 
350 	if (device_may_wakeup(&pdev->dev)) {
351 		if (kbd->irq_wake_enabled) {
352 			kbd->irq_wake_enabled = false;
353 			disable_irq_wake(kbd->irq);
354 		}
355 	} else {
356 		if (input_dev->users)
357 			clk_enable(kbd->clk);
358 	}
359 
360 	/* restore current configuration */
361 	if (input_dev->users)
362 		writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
363 
364 	mutex_unlock(&input_dev->mutex);
365 
366 	return 0;
367 }
368 
369 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
370 
371 #ifdef CONFIG_OF
372 static const struct of_device_id spear_kbd_id_table[] = {
373 	{ .compatible = "st,spear300-kbd" },
374 	{}
375 };
376 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
377 #endif
378 
379 static struct platform_driver spear_kbd_driver = {
380 	.probe		= spear_kbd_probe,
381 	.remove		= spear_kbd_remove,
382 	.driver		= {
383 		.name	= "keyboard",
384 		.pm	= &spear_kbd_pm_ops,
385 		.of_match_table = of_match_ptr(spear_kbd_id_table),
386 	},
387 };
388 module_platform_driver(spear_kbd_driver);
389 
390 MODULE_AUTHOR("Rajeev Kumar");
391 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
392 MODULE_LICENSE("GPL");
393