1 /*
2  * SPEAr Keyboard Driver
3  * Based on omap-keypad driver
4  *
5  * Copyright (C) 2010 ST Microelectronics
6  * Rajeev Kumar<rajeev-dlh.kumar@st.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/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/input.h>
18 #include <linux/io.h>
19 #include <linux/irq.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/pm_wakeup.h>
25 #include <linux/slab.h>
26 #include <linux/types.h>
27 #include <linux/platform_data/keyboard-spear.h>
28 
29 /* Keyboard Registers */
30 #define MODE_CTL_REG	0x00
31 #define STATUS_REG	0x0C
32 #define DATA_REG	0x10
33 #define INTR_MASK	0x54
34 
35 /* Register Values */
36 #define NUM_ROWS	16
37 #define NUM_COLS	16
38 #define MODE_CTL_PCLK_FREQ_SHIFT	9
39 #define MODE_CTL_PCLK_FREQ_MSK		0x7F
40 
41 #define MODE_CTL_KEYBOARD	(0x2 << 0)
42 #define MODE_CTL_SCAN_RATE_10	(0x0 << 2)
43 #define MODE_CTL_SCAN_RATE_20	(0x1 << 2)
44 #define MODE_CTL_SCAN_RATE_40	(0x2 << 2)
45 #define MODE_CTL_SCAN_RATE_80	(0x3 << 2)
46 #define MODE_CTL_KEYNUM_SHIFT	6
47 #define MODE_CTL_START_SCAN	(0x1 << 8)
48 
49 #define STATUS_DATA_AVAIL	(0x1 << 1)
50 
51 #define DATA_ROW_MASK		0xF0
52 #define DATA_COLUMN_MASK	0x0F
53 
54 #define ROW_SHIFT		4
55 
56 struct spear_kbd {
57 	struct input_dev *input;
58 	void __iomem *io_base;
59 	struct clk *clk;
60 	unsigned int irq;
61 	unsigned int mode;
62 	unsigned int suspended_rate;
63 	unsigned short last_key;
64 	unsigned short keycodes[NUM_ROWS * NUM_COLS];
65 	bool rep;
66 	bool irq_wake_enabled;
67 	u32 mode_ctl_reg;
68 };
69 
70 static irqreturn_t spear_kbd_interrupt(int irq, void *dev_id)
71 {
72 	struct spear_kbd *kbd = dev_id;
73 	struct input_dev *input = kbd->input;
74 	unsigned int key;
75 	u32 sts, val;
76 
77 	sts = readl_relaxed(kbd->io_base + STATUS_REG);
78 	if (!(sts & STATUS_DATA_AVAIL))
79 		return IRQ_NONE;
80 
81 	if (kbd->last_key != KEY_RESERVED) {
82 		input_report_key(input, kbd->last_key, 0);
83 		kbd->last_key = KEY_RESERVED;
84 	}
85 
86 	/* following reads active (row, col) pair */
87 	val = readl_relaxed(kbd->io_base + DATA_REG) &
88 		(DATA_ROW_MASK | DATA_COLUMN_MASK);
89 	key = kbd->keycodes[val];
90 
91 	input_event(input, EV_MSC, MSC_SCAN, val);
92 	input_report_key(input, key, 1);
93 	input_sync(input);
94 
95 	kbd->last_key = key;
96 
97 	/* clear interrupt */
98 	writel_relaxed(0, kbd->io_base + STATUS_REG);
99 
100 	return IRQ_HANDLED;
101 }
102 
103 static int spear_kbd_open(struct input_dev *dev)
104 {
105 	struct spear_kbd *kbd = input_get_drvdata(dev);
106 	int error;
107 	u32 val;
108 
109 	kbd->last_key = KEY_RESERVED;
110 
111 	error = clk_enable(kbd->clk);
112 	if (error)
113 		return error;
114 
115 	/* keyboard rate to be programmed is input clock (in MHz) - 1 */
116 	val = clk_get_rate(kbd->clk) / 1000000 - 1;
117 	val = (val & MODE_CTL_PCLK_FREQ_MSK) << MODE_CTL_PCLK_FREQ_SHIFT;
118 
119 	/* program keyboard */
120 	val = MODE_CTL_SCAN_RATE_80 | MODE_CTL_KEYBOARD | val |
121 		(kbd->mode << MODE_CTL_KEYNUM_SHIFT);
122 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
123 	writel_relaxed(1, kbd->io_base + STATUS_REG);
124 
125 	/* start key scan */
126 	val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
127 	val |= MODE_CTL_START_SCAN;
128 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
129 
130 	return 0;
131 }
132 
133 static void spear_kbd_close(struct input_dev *dev)
134 {
135 	struct spear_kbd *kbd = input_get_drvdata(dev);
136 	u32 val;
137 
138 	/* stop key scan */
139 	val = readl_relaxed(kbd->io_base + MODE_CTL_REG);
140 	val &= ~MODE_CTL_START_SCAN;
141 	writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
142 
143 	clk_disable(kbd->clk);
144 
145 	kbd->last_key = KEY_RESERVED;
146 }
147 
148 #ifdef CONFIG_OF
149 static int spear_kbd_parse_dt(struct platform_device *pdev,
150                                         struct spear_kbd *kbd)
151 {
152 	struct device_node *np = pdev->dev.of_node;
153 	int error;
154 	u32 val, suspended_rate;
155 
156 	if (!np) {
157 		dev_err(&pdev->dev, "Missing DT data\n");
158 		return -EINVAL;
159 	}
160 
161 	if (of_property_read_bool(np, "autorepeat"))
162 		kbd->rep = true;
163 
164 	if (of_property_read_u32(np, "suspended_rate", &suspended_rate))
165 		kbd->suspended_rate = suspended_rate;
166 
167 	error = of_property_read_u32(np, "st,mode", &val);
168 	if (error) {
169 		dev_err(&pdev->dev, "DT: Invalid or missing mode\n");
170 		return error;
171 	}
172 
173 	kbd->mode = val;
174 	return 0;
175 }
176 #else
177 static inline int spear_kbd_parse_dt(struct platform_device *pdev,
178 				     struct spear_kbd *kbd)
179 {
180 	return -ENOSYS;
181 }
182 #endif
183 
184 static int spear_kbd_probe(struct platform_device *pdev)
185 {
186 	struct kbd_platform_data *pdata = dev_get_platdata(&pdev->dev);
187 	const struct matrix_keymap_data *keymap = pdata ? pdata->keymap : NULL;
188 	struct spear_kbd *kbd;
189 	struct input_dev *input_dev;
190 	struct resource *res;
191 	int irq;
192 	int error;
193 
194 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
195 	if (!res) {
196 		dev_err(&pdev->dev, "no keyboard resource defined\n");
197 		return -EBUSY;
198 	}
199 
200 	irq = platform_get_irq(pdev, 0);
201 	if (irq < 0) {
202 		dev_err(&pdev->dev, "not able to get irq for the device\n");
203 		return irq;
204 	}
205 
206 	kbd = devm_kzalloc(&pdev->dev, sizeof(*kbd), GFP_KERNEL);
207 	if (!kbd) {
208 		dev_err(&pdev->dev, "not enough memory for driver data\n");
209 		return -ENOMEM;
210 	}
211 
212 	input_dev = devm_input_allocate_device(&pdev->dev);
213 	if (!input_dev) {
214 		dev_err(&pdev->dev, "unable to allocate input device\n");
215 		return -ENOMEM;
216 	}
217 
218 	kbd->input = input_dev;
219 	kbd->irq = irq;
220 
221 	if (!pdata) {
222 		error = spear_kbd_parse_dt(pdev, kbd);
223 		if (error)
224 			return error;
225 	} else {
226 		kbd->mode = pdata->mode;
227 		kbd->rep = pdata->rep;
228 		kbd->suspended_rate = pdata->suspended_rate;
229 	}
230 
231 	kbd->io_base = devm_ioremap_resource(&pdev->dev, res);
232 	if (IS_ERR(kbd->io_base))
233 		return PTR_ERR(kbd->io_base);
234 
235 	kbd->clk = devm_clk_get(&pdev->dev, NULL);
236 	if (IS_ERR(kbd->clk))
237 		return PTR_ERR(kbd->clk);
238 
239 	input_dev->name = "Spear Keyboard";
240 	input_dev->phys = "keyboard/input0";
241 	input_dev->id.bustype = BUS_HOST;
242 	input_dev->id.vendor = 0x0001;
243 	input_dev->id.product = 0x0001;
244 	input_dev->id.version = 0x0100;
245 	input_dev->open = spear_kbd_open;
246 	input_dev->close = spear_kbd_close;
247 
248 	error = matrix_keypad_build_keymap(keymap, NULL, NUM_ROWS, NUM_COLS,
249 					   kbd->keycodes, input_dev);
250 	if (error) {
251 		dev_err(&pdev->dev, "Failed to build keymap\n");
252 		return error;
253 	}
254 
255 	if (kbd->rep)
256 		__set_bit(EV_REP, input_dev->evbit);
257 	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
258 
259 	input_set_drvdata(input_dev, kbd);
260 
261 	error = devm_request_irq(&pdev->dev, irq, spear_kbd_interrupt, 0,
262 			"keyboard", kbd);
263 	if (error) {
264 		dev_err(&pdev->dev, "request_irq failed\n");
265 		return error;
266 	}
267 
268 	error = clk_prepare(kbd->clk);
269 	if (error)
270 		return error;
271 
272 	error = input_register_device(input_dev);
273 	if (error) {
274 		dev_err(&pdev->dev, "Unable to register keyboard device\n");
275 		clk_unprepare(kbd->clk);
276 		return error;
277 	}
278 
279 	device_init_wakeup(&pdev->dev, 1);
280 	platform_set_drvdata(pdev, kbd);
281 
282 	return 0;
283 }
284 
285 static int spear_kbd_remove(struct platform_device *pdev)
286 {
287 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
288 
289 	input_unregister_device(kbd->input);
290 	clk_unprepare(kbd->clk);
291 
292 	device_init_wakeup(&pdev->dev, 0);
293 	platform_set_drvdata(pdev, NULL);
294 
295 	return 0;
296 }
297 
298 #ifdef CONFIG_PM
299 static int spear_kbd_suspend(struct device *dev)
300 {
301 	struct platform_device *pdev = to_platform_device(dev);
302 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
303 	struct input_dev *input_dev = kbd->input;
304 	unsigned int rate = 0, mode_ctl_reg, val;
305 
306 	mutex_lock(&input_dev->mutex);
307 
308 	/* explicitly enable clock as we may program device */
309 	clk_enable(kbd->clk);
310 
311 	mode_ctl_reg = readl_relaxed(kbd->io_base + MODE_CTL_REG);
312 
313 	if (device_may_wakeup(&pdev->dev)) {
314 		if (!enable_irq_wake(kbd->irq))
315 			kbd->irq_wake_enabled = true;
316 
317 		/*
318 		 * reprogram the keyboard operating frequency as on some
319 		 * platform it may change during system suspended
320 		 */
321 		if (kbd->suspended_rate)
322 			rate = kbd->suspended_rate / 1000000 - 1;
323 		else
324 			rate = clk_get_rate(kbd->clk) / 1000000 - 1;
325 
326 		val = mode_ctl_reg &
327 			~(MODE_CTL_PCLK_FREQ_MSK << MODE_CTL_PCLK_FREQ_SHIFT);
328 		val |= (rate & MODE_CTL_PCLK_FREQ_MSK)
329 			<< MODE_CTL_PCLK_FREQ_SHIFT;
330 		writel_relaxed(val, kbd->io_base + MODE_CTL_REG);
331 
332 	} else {
333 		if (input_dev->users) {
334 			writel_relaxed(mode_ctl_reg & ~MODE_CTL_START_SCAN,
335 					kbd->io_base + MODE_CTL_REG);
336 			clk_disable(kbd->clk);
337 		}
338 	}
339 
340 	/* store current configuration */
341 	if (input_dev->users)
342 		kbd->mode_ctl_reg = mode_ctl_reg;
343 
344 	/* restore previous clk state */
345 	clk_disable(kbd->clk);
346 
347 	mutex_unlock(&input_dev->mutex);
348 
349 	return 0;
350 }
351 
352 static int spear_kbd_resume(struct device *dev)
353 {
354 	struct platform_device *pdev = to_platform_device(dev);
355 	struct spear_kbd *kbd = platform_get_drvdata(pdev);
356 	struct input_dev *input_dev = kbd->input;
357 
358 	mutex_lock(&input_dev->mutex);
359 
360 	if (device_may_wakeup(&pdev->dev)) {
361 		if (kbd->irq_wake_enabled) {
362 			kbd->irq_wake_enabled = false;
363 			disable_irq_wake(kbd->irq);
364 		}
365 	} else {
366 		if (input_dev->users)
367 			clk_enable(kbd->clk);
368 	}
369 
370 	/* restore current configuration */
371 	if (input_dev->users)
372 		writel_relaxed(kbd->mode_ctl_reg, kbd->io_base + MODE_CTL_REG);
373 
374 	mutex_unlock(&input_dev->mutex);
375 
376 	return 0;
377 }
378 #endif
379 
380 static SIMPLE_DEV_PM_OPS(spear_kbd_pm_ops, spear_kbd_suspend, spear_kbd_resume);
381 
382 #ifdef CONFIG_OF
383 static const struct of_device_id spear_kbd_id_table[] = {
384 	{ .compatible = "st,spear300-kbd" },
385 	{}
386 };
387 MODULE_DEVICE_TABLE(of, spear_kbd_id_table);
388 #endif
389 
390 static struct platform_driver spear_kbd_driver = {
391 	.probe		= spear_kbd_probe,
392 	.remove		= spear_kbd_remove,
393 	.driver		= {
394 		.name	= "keyboard",
395 		.owner	= THIS_MODULE,
396 		.pm	= &spear_kbd_pm_ops,
397 		.of_match_table = of_match_ptr(spear_kbd_id_table),
398 	},
399 };
400 module_platform_driver(spear_kbd_driver);
401 
402 MODULE_AUTHOR("Rajeev Kumar");
403 MODULE_DESCRIPTION("SPEAr Keyboard Driver");
404 MODULE_LICENSE("GPL");
405