1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) ST-Ericsson SA 2010
4  *
5  * Author: Naveen Kumar G <naveen.gaddipati@stericsson.com> for ST-Ericsson
6  * Author: Sundar Iyer <sundar.iyer@stericsson.com> for ST-Ericsson
7  *
8  * Keypad controller driver for the SKE (Scroll Key Encoder) module used in
9  * the Nomadik 8815 and Ux500 platforms.
10  */
11 
12 #include <linux/platform_device.h>
13 #include <linux/interrupt.h>
14 #include <linux/spinlock.h>
15 #include <linux/io.h>
16 #include <linux/delay.h>
17 #include <linux/input.h>
18 #include <linux/slab.h>
19 #include <linux/clk.h>
20 #include <linux/module.h>
21 
22 #include <linux/platform_data/keypad-nomadik-ske.h>
23 
24 /* SKE_CR bits */
25 #define SKE_KPMLT	(0x1 << 6)
26 #define SKE_KPCN	(0x7 << 3)
27 #define SKE_KPASEN	(0x1 << 2)
28 #define SKE_KPASON	(0x1 << 7)
29 
30 /* SKE_IMSC bits */
31 #define SKE_KPIMA	(0x1 << 2)
32 
33 /* SKE_ICR bits */
34 #define SKE_KPICS	(0x1 << 3)
35 #define SKE_KPICA	(0x1 << 2)
36 
37 /* SKE_RIS bits */
38 #define SKE_KPRISA	(0x1 << 2)
39 
40 #define SKE_KEYPAD_ROW_SHIFT	3
41 #define SKE_KPD_NUM_ROWS	8
42 #define SKE_KPD_NUM_COLS	8
43 
44 /* keypad auto scan registers */
45 #define SKE_ASR0	0x20
46 #define SKE_ASR1	0x24
47 #define SKE_ASR2	0x28
48 #define SKE_ASR3	0x2C
49 
50 #define SKE_NUM_ASRX_REGISTERS	(4)
51 #define	KEY_PRESSED_DELAY	10
52 
53 /**
54  * struct ske_keypad  - data structure used by keypad driver
55  * @irq:	irq no
56  * @reg_base:	ske registers base address
57  * @input:	pointer to input device object
58  * @board:	keypad platform device
59  * @keymap:	matrix scan code table for keycodes
60  * @clk:	clock structure pointer
61  * @pclk:	clock structure pointer
62  * @ske_keypad_lock: spinlock protecting the keypad read/writes
63  */
64 struct ske_keypad {
65 	int irq;
66 	void __iomem *reg_base;
67 	struct input_dev *input;
68 	const struct ske_keypad_platform_data *board;
69 	unsigned short keymap[SKE_KPD_NUM_ROWS * SKE_KPD_NUM_COLS];
70 	struct clk *clk;
71 	struct clk *pclk;
72 	spinlock_t ske_keypad_lock;
73 };
74 
ske_keypad_set_bits(struct ske_keypad * keypad,u16 addr,u8 mask,u8 data)75 static void ske_keypad_set_bits(struct ske_keypad *keypad, u16 addr,
76 		u8 mask, u8 data)
77 {
78 	u32 ret;
79 
80 	spin_lock(&keypad->ske_keypad_lock);
81 
82 	ret = readl(keypad->reg_base + addr);
83 	ret &= ~mask;
84 	ret |= data;
85 	writel(ret, keypad->reg_base + addr);
86 
87 	spin_unlock(&keypad->ske_keypad_lock);
88 }
89 
90 /*
91  * ske_keypad_chip_init: init keypad controller configuration
92  *
93  * Enable Multi key press detection, auto scan mode
94  */
ske_keypad_chip_init(struct ske_keypad * keypad)95 static int __init ske_keypad_chip_init(struct ske_keypad *keypad)
96 {
97 	u32 value;
98 	int timeout = keypad->board->debounce_ms;
99 
100 	/* check SKE_RIS to be 0 */
101 	while ((readl(keypad->reg_base + SKE_RIS) != 0x00000000) && timeout--)
102 		cpu_relax();
103 
104 	if (timeout == -1)
105 		return -EINVAL;
106 
107 	/*
108 	 * set debounce value
109 	 * keypad dbounce is configured in DBCR[15:8]
110 	 * dbounce value in steps of 32/32.768 ms
111 	 */
112 	spin_lock(&keypad->ske_keypad_lock);
113 	value = readl(keypad->reg_base + SKE_DBCR);
114 	value = value & 0xff;
115 	value |= ((keypad->board->debounce_ms * 32000)/32768) << 8;
116 	writel(value, keypad->reg_base + SKE_DBCR);
117 	spin_unlock(&keypad->ske_keypad_lock);
118 
119 	/* enable multi key detection */
120 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPMLT);
121 
122 	/*
123 	 * set up the number of columns
124 	 * KPCN[5:3] defines no. of keypad columns to be auto scanned
125 	 */
126 	value = (keypad->board->kcol - 1) << 3;
127 	ske_keypad_set_bits(keypad, SKE_CR, SKE_KPCN, value);
128 
129 	/* clear keypad interrupt for auto(and pending SW) scans */
130 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA | SKE_KPICS);
131 
132 	/* un-mask keypad interrupts */
133 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
134 
135 	/* enable automatic scan */
136 	ske_keypad_set_bits(keypad, SKE_CR, 0x0, SKE_KPASEN);
137 
138 	return 0;
139 }
140 
ske_keypad_report(struct ske_keypad * keypad,u8 status,int col)141 static void ske_keypad_report(struct ske_keypad *keypad, u8 status, int col)
142 {
143 	int row = 0, code, pos;
144 	struct input_dev *input = keypad->input;
145 	u32 ske_ris;
146 	int key_pressed;
147 	int num_of_rows;
148 
149 	/* find out the row */
150 	num_of_rows = hweight8(status);
151 	do {
152 		pos = __ffs(status);
153 		row = pos;
154 		status &= ~(1 << pos);
155 
156 		code = MATRIX_SCAN_CODE(row, col, SKE_KEYPAD_ROW_SHIFT);
157 		ske_ris = readl(keypad->reg_base + SKE_RIS);
158 		key_pressed = ske_ris & SKE_KPRISA;
159 
160 		input_event(input, EV_MSC, MSC_SCAN, code);
161 		input_report_key(input, keypad->keymap[code], key_pressed);
162 		input_sync(input);
163 		num_of_rows--;
164 	} while (num_of_rows);
165 }
166 
ske_keypad_read_data(struct ske_keypad * keypad)167 static void ske_keypad_read_data(struct ske_keypad *keypad)
168 {
169 	u8 status;
170 	int col = 0;
171 	int ske_asr, i;
172 
173 	/*
174 	 * Read the auto scan registers
175 	 *
176 	 * Each SKE_ASRx (x=0 to x=3) contains two row values.
177 	 * lower byte contains row value for column 2*x,
178 	 * upper byte contains row value for column 2*x + 1
179 	 */
180 	for (i = 0; i < SKE_NUM_ASRX_REGISTERS; i++) {
181 		ske_asr = readl(keypad->reg_base + SKE_ASR0 + (4 * i));
182 		if (!ske_asr)
183 			continue;
184 
185 		/* now that ASRx is zero, find out the coloumn x and row y */
186 		status = ske_asr & 0xff;
187 		if (status) {
188 			col = i * 2;
189 			ske_keypad_report(keypad, status, col);
190 		}
191 		status = (ske_asr & 0xff00) >> 8;
192 		if (status) {
193 			col = (i * 2) + 1;
194 			ske_keypad_report(keypad, status, col);
195 		}
196 	}
197 }
198 
ske_keypad_irq(int irq,void * dev_id)199 static irqreturn_t ske_keypad_irq(int irq, void *dev_id)
200 {
201 	struct ske_keypad *keypad = dev_id;
202 	int timeout = keypad->board->debounce_ms;
203 
204 	/* disable auto scan interrupt; mask the interrupt generated */
205 	ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
206 	ske_keypad_set_bits(keypad, SKE_ICR, 0x0, SKE_KPICA);
207 
208 	while ((readl(keypad->reg_base + SKE_CR) & SKE_KPASON) && --timeout)
209 		cpu_relax();
210 
211 	/* SKEx registers are stable and can be read */
212 	ske_keypad_read_data(keypad);
213 
214 	/* wait until raw interrupt is clear */
215 	while ((readl(keypad->reg_base + SKE_RIS)) && --timeout)
216 		msleep(KEY_PRESSED_DELAY);
217 
218 	/* enable auto scan interrupts */
219 	ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
220 
221 	return IRQ_HANDLED;
222 }
223 
ske_keypad_board_exit(void * data)224 static void ske_keypad_board_exit(void *data)
225 {
226 	struct ske_keypad *keypad = data;
227 
228 	keypad->board->exit();
229 }
230 
ske_keypad_probe(struct platform_device * pdev)231 static int __init ske_keypad_probe(struct platform_device *pdev)
232 {
233 	const struct ske_keypad_platform_data *plat =
234 			dev_get_platdata(&pdev->dev);
235 	struct device *dev = &pdev->dev;
236 	struct ske_keypad *keypad;
237 	struct input_dev *input;
238 	int irq;
239 	int error;
240 
241 	if (!plat) {
242 		dev_err(&pdev->dev, "invalid keypad platform data\n");
243 		return -EINVAL;
244 	}
245 
246 	irq = platform_get_irq(pdev, 0);
247 	if (irq < 0)
248 		return irq;
249 
250 	keypad = devm_kzalloc(dev, sizeof(struct ske_keypad),
251 			      GFP_KERNEL);
252 	input = devm_input_allocate_device(dev);
253 	if (!keypad || !input) {
254 		dev_err(&pdev->dev, "failed to allocate keypad memory\n");
255 		return -ENOMEM;
256 	}
257 
258 	keypad->irq = irq;
259 	keypad->board = plat;
260 	keypad->input = input;
261 	spin_lock_init(&keypad->ske_keypad_lock);
262 
263 	keypad->reg_base = devm_platform_ioremap_resource(pdev, 0);
264 	if (IS_ERR(keypad->reg_base))
265 		return PTR_ERR(keypad->reg_base);
266 
267 	keypad->pclk = devm_clk_get_enabled(dev, "apb_pclk");
268 	if (IS_ERR(keypad->pclk)) {
269 		dev_err(&pdev->dev, "failed to get pclk\n");
270 		return PTR_ERR(keypad->pclk);
271 	}
272 
273 	keypad->clk = devm_clk_get_enabled(dev, NULL);
274 	if (IS_ERR(keypad->clk)) {
275 		dev_err(&pdev->dev, "failed to get clk\n");
276 		return PTR_ERR(keypad->clk);
277 	}
278 
279 	input->id.bustype = BUS_HOST;
280 	input->name = "ux500-ske-keypad";
281 	input->dev.parent = &pdev->dev;
282 
283 	error = matrix_keypad_build_keymap(plat->keymap_data, NULL,
284 					   SKE_KPD_NUM_ROWS, SKE_KPD_NUM_COLS,
285 					   keypad->keymap, input);
286 	if (error) {
287 		dev_err(&pdev->dev, "Failed to build keymap\n");
288 		return error;
289 	}
290 
291 	input_set_capability(input, EV_MSC, MSC_SCAN);
292 	if (!plat->no_autorepeat)
293 		__set_bit(EV_REP, input->evbit);
294 
295 	/* go through board initialization helpers */
296 	if (keypad->board->init)
297 		keypad->board->init();
298 
299 	if (keypad->board->exit) {
300 		error = devm_add_action_or_reset(dev, ske_keypad_board_exit,
301 						 keypad);
302 		if (error)
303 			return error;
304 	}
305 
306 	error = ske_keypad_chip_init(keypad);
307 	if (error) {
308 		dev_err(&pdev->dev, "unable to init keypad hardware\n");
309 		return error;
310 	}
311 
312 	error = devm_request_threaded_irq(dev, keypad->irq,
313 					  NULL, ske_keypad_irq,
314 					  IRQF_ONESHOT, "ske-keypad", keypad);
315 	if (error) {
316 		dev_err(&pdev->dev, "allocate irq %d failed\n", keypad->irq);
317 		return error;
318 	}
319 
320 	error = input_register_device(input);
321 	if (error) {
322 		dev_err(&pdev->dev,
323 			"unable to register input device: %d\n", error);
324 		return error;
325 	}
326 
327 	if (plat->wakeup_enable)
328 		device_init_wakeup(&pdev->dev, true);
329 
330 	platform_set_drvdata(pdev, keypad);
331 
332 	return 0;
333 }
334 
ske_keypad_suspend(struct device * dev)335 static int ske_keypad_suspend(struct device *dev)
336 {
337 	struct platform_device *pdev = to_platform_device(dev);
338 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
339 	int irq = platform_get_irq(pdev, 0);
340 
341 	if (device_may_wakeup(dev))
342 		enable_irq_wake(irq);
343 	else
344 		ske_keypad_set_bits(keypad, SKE_IMSC, ~SKE_KPIMA, 0x0);
345 
346 	return 0;
347 }
348 
ske_keypad_resume(struct device * dev)349 static int ske_keypad_resume(struct device *dev)
350 {
351 	struct platform_device *pdev = to_platform_device(dev);
352 	struct ske_keypad *keypad = platform_get_drvdata(pdev);
353 	int irq = platform_get_irq(pdev, 0);
354 
355 	if (device_may_wakeup(dev))
356 		disable_irq_wake(irq);
357 	else
358 		ske_keypad_set_bits(keypad, SKE_IMSC, 0x0, SKE_KPIMA);
359 
360 	return 0;
361 }
362 
363 static DEFINE_SIMPLE_DEV_PM_OPS(ske_keypad_dev_pm_ops,
364 				ske_keypad_suspend, ske_keypad_resume);
365 
366 static struct platform_driver ske_keypad_driver = {
367 	.driver = {
368 		.name = "nmk-ske-keypad",
369 		.pm = pm_sleep_ptr(&ske_keypad_dev_pm_ops),
370 	},
371 };
372 
373 module_platform_driver_probe(ske_keypad_driver, ske_keypad_probe);
374 
375 MODULE_LICENSE("GPL v2");
376 MODULE_AUTHOR("Naveen Kumar <naveen.gaddipati@stericsson.com> / Sundar Iyer <sundar.iyer@stericsson.com>");
377 MODULE_DESCRIPTION("Nomadik Scroll-Key-Encoder Keypad Driver");
378 MODULE_ALIAS("platform:nomadik-ske-keypad");
379