1 /*
2  * Copyright (C) ST-Ericsson SA 2010
3  *
4  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
5  * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
6  *
7  * License terms:GNU General Public License (GPL) version 2
8  *
9  * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
10  * the Nomadik 8815 and Ux500 platforms.
11  */
12 
13 #include <linux/platform_device.h>
14 #include <linux/interrupt.h>
15 #include <linux/spinlock.h>
16 #include <linux/io.h>
17 #include <linux/delay.h>
18 #include <linux/input.h>
19 #include <linux/slab.h>
20 #include <linux/clk.h>
21 #include <linux/module.h>
22 
23 #include <linux/platform_data/keypad-nomadik-ske.h>
24 
25 /* SKE_CR bits */
26 #define SKE_KPMLT	(0x1 << 6)
27 #define SKE_KPCN	(0x7 << 3)
28 #define SKE_KPASEN	(0x1 << 2)
29 #define SKE_KPASON	(0x1 << 7)
30 
31 /* SKE_IMSC bits */
32 #define SKE_KPIMA	(0x1 << 2)
33 
34 /* SKE_ICR bits */
35 #define SKE_KPICS	(0x1 << 3)
36 #define SKE_KPICA	(0x1 << 2)
37 
38 /* SKE_RIS bits */
39 #define SKE_KPRISA	(0x1 << 2)
40 
41 #define SKE_KEYPAD_ROW_SHIFT	3
42 #define SKE_KPD_NUM_ROWS	8
43 #define SKE_KPD_NUM_COLS	8
44 
45 /* keypad auto scan registers */
46 #define SKE_ASR0	0x20
47 #define SKE_ASR1	0x24
48 #define SKE_ASR2	0x28
49 #define SKE_ASR3	0x2C
50 
51 #define SKE_NUM_ASRX_REGISTERS	(4)
52 #define	KEY_PRESSED_DELAY	10
53 
54 /**
55  * struct ske_keypad  - data structure used by keypad driver
56  * @irq:	irq no
57  * @reg_base:	ske registers base address
58  * @input:	pointer to input device object
59  * @board:	keypad platform device
60  * @keymap:	matrix scan code table for keycodes
61  * @clk:	clock structure pointer
62  */
63 struct ske_keypad {
64 	int irq;
65 	void __iomem *reg_base;
66 	struct input_dev *input;
67 	const struct ske_keypad_platform_data *board;
68 	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
69 	struct clk *clk;
70 	struct clk *pclk;
71 	spinlock_t ske_keypad_lock;
72 };
73 
74 static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
75 		u8 mask, u8 data)
76 {
77 	u32 ret;
78 
79 	spin_lock(&keypad->ske_keypad_lock);
80 
81 	ret = readl(keypad->reg_base + addr);
82 	ret &= ~mask;
83 	ret |= data;
84 	writel(ret, keypad->reg_base + addr);
85 
86 	spin_unlock(&keypad->ske_keypad_lock);
87 }
88 
89 /*
90  * ske_keypad_chip_init: init keypad controller configuration
91  *
92  * Enable Multi key press detection, auto scan mode
93  */
94 static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
95 {
96 	u32 value;
97 	int timeout = keypad->board->debounce_ms;
98 
99 	/* check SKE_RIS to be 0 */
100 	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
101 		cpu_relax();
102 
103 	if (!timeout)
104 		return -EINVAL;
105 
106 	/*
107 	 * set debounce value
108 	 * keypad dbounce is configured in DBCR[15:8]
109 	 * dbounce value in steps of 32/32.768 ms
110 	 */
111 	spin_lock(&keypad->ske_keypad_lock);
112 	value = readl(keypad->reg_base + SKE_DBCR);
113 	value = value & 0xff;
114 	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
115 	writel(value, keypad->reg_base + SKE_DBCR);
116 	spin_unlock(&keypad->ske_keypad_lock);
117 
118 	/* enable multi key detection */
119 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
120 
121 	/*
122 	 * set up the number of columns
123 	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
124 	 */
125 	value = (keypad->board->kcol - 1) << 3;
126 	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
127 
128 	/* clear keypad interrupt for auto(and pending SW) scans */
129 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
130 
131 	/* un-mask keypad interrupts */
132 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
133 
134 	/* enable automatic scan */
135 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
136 
137 	return 0;
138 }
139 
140 static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
141 {
142 	int row = 0, code, pos;
143 	struct input_dev *input = keypad->input;
144 	u32 ske_ris;
145 	int key_pressed;
146 	int num_of_rows;
147 
148 	/* find out the row */
149 	num_of_rows = hweight8(status);
150 	do {
151 		pos = __ffs(status);
152 		row = pos;
153 		status &= ~(1 << pos);
154 
155 		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
156 		ske_ris = readl(keypad->reg_base + SKE_RIS);
157 		key_pressed = ske_ris & SKE_KPRISA;
158 
159 		input_event(input, EV_MSC, MSC_SCAN, code);
160 		input_report_key(input, keypad->keymap[code], key_pressed);
161 		input_sync(input);
162 		num_of_rows--;
163 	} while (num_of_rows);
164 }
165 
166 static void ske_keypad_read_data(struct ske_keypad *keypad)
167 {
168 	u8 status;
169 	int col = 0;
170 	int ske_asr, i;
171 
172 	/*
173 	 * Read the auto scan registers
174 	 *
175 	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
176 	 * lower byte contains row value for column 2*x,
177 	 * upper byte contains row value for column 2*x + 1
178 	 */
179 	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
180 		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
181 		if (!ske_asr)
182 			continue;
183 
184 		/* now that ASRx is zero, find out the coloumn x and row y */
185 		status = ske_asr & 0xff;
186 		if (status) {
187 			col = i * 2;
188 			ske_keypad_report(keypad, status, col);
189 		}
190 		status = (ske_asr & 0xff00) >> 8;
191 		if (status) {
192 			col = (i * 2) + 1;
193 			ske_keypad_report(keypad, status, col);
194 		}
195 	}
196 }
197 
198 static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
199 {
200 	struct ske_keypad *keypad = dev_id;
201 	int timeout = keypad->board->debounce_ms;
202 
203 	/* disable auto scan interrupt; mask the interrupt generated */
204 	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
205 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
206 
207 	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
208 		cpu_relax();
209 
210 	/* SKEx registers are stable and can be read */
211 	ske_keypad_read_data(keypad);
212 
213 	/* wait until raw interrupt is clear */
214 	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
215 		msleep(KEY_PRESSED_DELAY);
216 
217 	/* enable auto scan interrupts */
218 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
219 
220 	return IRQ_HANDLED;
221 }
222 
223 static int __init ske_keypad_probe(struct platform_device *pdev)
224 {
225 	const struct ske_keypad_platform_data *plat =
226 			dev_get_platdata(&pdev->dev);
227 	struct ske_keypad *keypad;
228 	struct input_dev *input;
229 	struct resource *res;
230 	int irq;
231 	int error;
232 
233 	if (!plat) {
234 		dev_err(&pdev->dev, "invalid keypad platform data\n");
235 		return -EINVAL;
236 	}
237 
238 	irq = platform_get_irq(pdev, 0);
239 	if (irq < 0) {
240 		dev_err(&pdev->dev, "failed to get keypad irq\n");
241 		return -EINVAL;
242 	}
243 
244 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
245 	if (!res) {
246 		dev_err(&pdev->dev, "missing platform resources\n");
247 		return -EINVAL;
248 	}
249 
250 	keypad = kzalloc(sizeof(struct ske_keypad), GFP_KERNEL);
251 	input = input_allocate_device();
252 	if (!keypad || !input) {
253 		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
254 		error = -ENOMEM;
255 		goto err_free_mem;
256 	}
257 
258 	keypad->irq = irq;
259 	keypad->board = plat;
260 	keypad->input = input;
261 	spin_lock_init(&keypad->ske_keypad_lock);
262 
263 	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
264 		dev_err(&pdev->dev, "failed to request I/O memory\n");
265 		error = -EBUSY;
266 		goto err_free_mem;
267 	}
268 
269 	keypad->reg_base = ioremap(res->start, resource_size(res));
270 	if (!keypad->reg_base) {
271 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
272 		error = -ENXIO;
273 		goto err_free_mem_region;
274 	}
275 
276 	keypad->pclk = clk_get(&pdev->dev, "apb_pclk");
277 	if (IS_ERR(keypad->pclk)) {
278 		dev_err(&pdev->dev, "failed to get pclk\n");
279 		error = PTR_ERR(keypad->pclk);
280 		goto err_iounmap;
281 	}
282 
283 	keypad->clk = clk_get(&pdev->dev, NULL);
284 	if (IS_ERR(keypad->clk)) {
285 		dev_err(&pdev->dev, "failed to get clk\n");
286 		error = PTR_ERR(keypad->clk);
287 		goto err_pclk;
288 	}
289 
290 	input->id.bustype = BUS_HOST;
291 	input->name = "ux500-ske-keypad";
292 	input->dev.parent = &pdev->dev;
293 
294 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
295 					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
296 					   keypad->keymap, input);
297 	if (error) {
298 		dev_err(&pdev->dev, "Failed to build keymap\n");
299 		goto err_clk;
300 	}
301 
302 	input_set_capability(input, EV_MSC, MSC_SCAN);
303 	if (!plat->no_autorepeat)
304 		__set_bit(EV_REP, input->evbit);
305 
306 	error = clk_prepare_enable(keypad->pclk);
307 	if (error) {
308 		dev_err(&pdev->dev, "Failed to prepare/enable pclk\n");
309 		goto err_clk;
310 	}
311 
312 	error = clk_prepare_enable(keypad->clk);
313 	if (error) {
314 		dev_err(&pdev->dev, "Failed to prepare/enable clk\n");
315 		goto err_pclk_disable;
316 	}
317 
318 
319 	/* go through board initialization helpers */
320 	if (keypad->board->init)
321 		keypad->board->init();
322 
323 	error = ske_keypad_chip_init(keypad);
324 	if (error) {
325 		dev_err(&pdev->dev, "unable to init keypad hardware\n");
326 		goto err_clk_disable;
327 	}
328 
329 	error = request_threaded_irq(keypad->irq, NULL, ske_keypad_irq,
330 				     IRQF_ONESHOT, "ske-keypad", keypad);
331 	if (error) {
332 		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
333 		goto err_clk_disable;
334 	}
335 
336 	error = input_register_device(input);
337 	if (error) {
338 		dev_err(&pdev->dev,
339 				"unable to register input device: %d\n", error);
340 		goto err_free_irq;
341 	}
342 
343 	if (plat->wakeup_enable)
344 		device_init_wakeup(&pdev->dev, true);
345 
346 	platform_set_drvdata(pdev, keypad);
347 
348 	return 0;
349 
350 err_free_irq:
351 	free_irq(keypad->irq, keypad);
352 err_clk_disable:
353 	clk_disable_unprepare(keypad->clk);
354 err_pclk_disable:
355 	clk_disable_unprepare(keypad->pclk);
356 err_clk:
357 	clk_put(keypad->clk);
358 err_pclk:
359 	clk_put(keypad->pclk);
360 err_iounmap:
361 	iounmap(keypad->reg_base);
362 err_free_mem_region:
363 	release_mem_region(res->start, resource_size(res));
364 err_free_mem:
365 	input_free_device(input);
366 	kfree(keypad);
367 	return error;
368 }
369 
370 static int ske_keypad_remove(struct platform_device *pdev)
371 {
372 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
373 	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
374 
375 	free_irq(keypad->irq, keypad);
376 
377 	input_unregister_device(keypad->input);
378 
379 	clk_disable_unprepare(keypad->clk);
380 	clk_put(keypad->clk);
381 
382 	if (keypad->board->exit)
383 		keypad->board->exit();
384 
385 	iounmap(keypad->reg_base);
386 	release_mem_region(res->start, resource_size(res));
387 	kfree(keypad);
388 
389 	return 0;
390 }
391 
392 #ifdef CONFIG_PM_SLEEP
393 static int ske_keypad_suspend(struct device *dev)
394 {
395 	struct platform_device *pdev = to_platform_device(dev);
396 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
397 	int irq = platform_get_irq(pdev, 0);
398 
399 	if (device_may_wakeup(dev))
400 		enable_irq_wake(irq);
401 	else
402 		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
403 
404 	return 0;
405 }
406 
407 static int ske_keypad_resume(struct device *dev)
408 {
409 	struct platform_device *pdev = to_platform_device(dev);
410 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
411 	int irq = platform_get_irq(pdev, 0);
412 
413 	if (device_may_wakeup(dev))
414 		disable_irq_wake(irq);
415 	else
416 		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
417 
418 	return 0;
419 }
420 #endif
421 
422 static SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
423 			 ske_keypad_suspend, ske_keypad_resume);
424 
425 static struct platform_driver ske_keypad_driver = {
426 	.driver = {
427 		.name = "nmk-ske-keypad",
428 		.pm = &ske_keypad_dev_pm_ops,
429 	},
430 	.remove = ske_keypad_remove,
431 };
432 
433 module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
434 
435 MODULE_LICENSE("GPL v2");
436 MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
437 MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
438 MODULE_ALIAS("platform:nomadik-ske-keypad");
439