1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SuperH KEYSC Keypad Driver
4  *
5  * Copyright (C) 2008 Magnus Damm
6  *
7  * Based on gpio_keys.c, Copyright 2005 Phil Blundell
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/delay.h>
15 #include <linux/platform_device.h>
16 #include <linux/input.h>
17 #include <linux/input/sh_keysc.h>
18 #include <linux/bitmap.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/io.h>
21 #include <linux/slab.h>
22 
23 static const struct {
24 	unsigned char kymd, keyout, keyin;
25 } sh_keysc_mode[] = {
26 	[SH_KEYSC_MODE_1] = { 0, 6, 5 },
27 	[SH_KEYSC_MODE_2] = { 1, 5, 6 },
28 	[SH_KEYSC_MODE_3] = { 2, 4, 7 },
29 	[SH_KEYSC_MODE_4] = { 3, 6, 6 },
30 	[SH_KEYSC_MODE_5] = { 4, 6, 7 },
31 	[SH_KEYSC_MODE_6] = { 5, 8, 8 },
32 };
33 
34 struct sh_keysc_priv {
35 	void __iomem *iomem_base;
36 	DECLARE_BITMAP(last_keys, SH_KEYSC_MAXKEYS);
37 	struct input_dev *input;
38 	struct sh_keysc_info pdata;
39 };
40 
41 #define KYCR1 0
42 #define KYCR2 1
43 #define KYINDR 2
44 #define KYOUTDR 3
45 
46 #define KYCR2_IRQ_LEVEL    0x10
47 #define KYCR2_IRQ_DISABLED 0x00
48 
49 static unsigned long sh_keysc_read(struct sh_keysc_priv *p, int reg_nr)
50 {
51 	return ioread16(p->iomem_base + (reg_nr << 2));
52 }
53 
54 static void sh_keysc_write(struct sh_keysc_priv *p, int reg_nr,
55 			   unsigned long value)
56 {
57 	iowrite16(value, p->iomem_base + (reg_nr << 2));
58 }
59 
60 static void sh_keysc_level_mode(struct sh_keysc_priv *p,
61 				unsigned long keys_set)
62 {
63 	struct sh_keysc_info *pdata = &p->pdata;
64 
65 	sh_keysc_write(p, KYOUTDR, 0);
66 	sh_keysc_write(p, KYCR2, KYCR2_IRQ_LEVEL | (keys_set << 8));
67 
68 	if (pdata->kycr2_delay)
69 		udelay(pdata->kycr2_delay);
70 }
71 
72 static void sh_keysc_map_dbg(struct device *dev, unsigned long *map,
73 			     const char *str)
74 {
75 	int k;
76 
77 	for (k = 0; k < BITS_TO_LONGS(SH_KEYSC_MAXKEYS); k++)
78 		dev_dbg(dev, "%s[%d] 0x%lx\n", str, k, map[k]);
79 }
80 
81 static irqreturn_t sh_keysc_isr(int irq, void *dev_id)
82 {
83 	struct platform_device *pdev = dev_id;
84 	struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
85 	struct sh_keysc_info *pdata = &priv->pdata;
86 	int keyout_nr = sh_keysc_mode[pdata->mode].keyout;
87 	int keyin_nr = sh_keysc_mode[pdata->mode].keyin;
88 	DECLARE_BITMAP(keys, SH_KEYSC_MAXKEYS);
89 	DECLARE_BITMAP(keys0, SH_KEYSC_MAXKEYS);
90 	DECLARE_BITMAP(keys1, SH_KEYSC_MAXKEYS);
91 	unsigned char keyin_set, tmp;
92 	int i, k, n;
93 
94 	dev_dbg(&pdev->dev, "isr!\n");
95 
96 	bitmap_fill(keys1, SH_KEYSC_MAXKEYS);
97 	bitmap_zero(keys0, SH_KEYSC_MAXKEYS);
98 
99 	do {
100 		bitmap_zero(keys, SH_KEYSC_MAXKEYS);
101 		keyin_set = 0;
102 
103 		sh_keysc_write(priv, KYCR2, KYCR2_IRQ_DISABLED);
104 
105 		for (i = 0; i < keyout_nr; i++) {
106 			n = keyin_nr * i;
107 
108 			/* drive one KEYOUT pin low, read KEYIN pins */
109 			sh_keysc_write(priv, KYOUTDR, 0xffff ^ (3 << (i * 2)));
110 			udelay(pdata->delay);
111 			tmp = sh_keysc_read(priv, KYINDR);
112 
113 			/* set bit if key press has been detected */
114 			for (k = 0; k < keyin_nr; k++) {
115 				if (tmp & (1 << k))
116 					__set_bit(n + k, keys);
117 			}
118 
119 			/* keep track of which KEYIN bits that have been set */
120 			keyin_set |= tmp ^ ((1 << keyin_nr) - 1);
121 		}
122 
123 		sh_keysc_level_mode(priv, keyin_set);
124 
125 		bitmap_complement(keys, keys, SH_KEYSC_MAXKEYS);
126 		bitmap_and(keys1, keys1, keys, SH_KEYSC_MAXKEYS);
127 		bitmap_or(keys0, keys0, keys, SH_KEYSC_MAXKEYS);
128 
129 		sh_keysc_map_dbg(&pdev->dev, keys, "keys");
130 
131 	} while (sh_keysc_read(priv, KYCR2) & 0x01);
132 
133 	sh_keysc_map_dbg(&pdev->dev, priv->last_keys, "last_keys");
134 	sh_keysc_map_dbg(&pdev->dev, keys0, "keys0");
135 	sh_keysc_map_dbg(&pdev->dev, keys1, "keys1");
136 
137 	for (i = 0; i < SH_KEYSC_MAXKEYS; i++) {
138 		k = pdata->keycodes[i];
139 		if (!k)
140 			continue;
141 
142 		if (test_bit(i, keys0) == test_bit(i, priv->last_keys))
143 			continue;
144 
145 		if (test_bit(i, keys1) || test_bit(i, keys0)) {
146 			input_event(priv->input, EV_KEY, k, 1);
147 			__set_bit(i, priv->last_keys);
148 		}
149 
150 		if (!test_bit(i, keys1)) {
151 			input_event(priv->input, EV_KEY, k, 0);
152 			__clear_bit(i, priv->last_keys);
153 		}
154 
155 	}
156 	input_sync(priv->input);
157 
158 	return IRQ_HANDLED;
159 }
160 
161 static int sh_keysc_probe(struct platform_device *pdev)
162 {
163 	struct sh_keysc_priv *priv;
164 	struct sh_keysc_info *pdata;
165 	struct resource *res;
166 	struct input_dev *input;
167 	int i;
168 	int irq, error;
169 
170 	if (!dev_get_platdata(&pdev->dev)) {
171 		dev_err(&pdev->dev, "no platform data defined\n");
172 		error = -EINVAL;
173 		goto err0;
174 	}
175 
176 	error = -ENXIO;
177 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
178 	if (res == NULL) {
179 		dev_err(&pdev->dev, "failed to get I/O memory\n");
180 		goto err0;
181 	}
182 
183 	irq = platform_get_irq(pdev, 0);
184 	if (irq < 0)
185 		goto err0;
186 
187 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
188 	if (priv == NULL) {
189 		dev_err(&pdev->dev, "failed to allocate driver data\n");
190 		error = -ENOMEM;
191 		goto err0;
192 	}
193 
194 	platform_set_drvdata(pdev, priv);
195 	memcpy(&priv->pdata, dev_get_platdata(&pdev->dev), sizeof(priv->pdata));
196 	pdata = &priv->pdata;
197 
198 	priv->iomem_base = ioremap(res->start, resource_size(res));
199 	if (priv->iomem_base == NULL) {
200 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
201 		error = -ENXIO;
202 		goto err1;
203 	}
204 
205 	priv->input = input_allocate_device();
206 	if (!priv->input) {
207 		dev_err(&pdev->dev, "failed to allocate input device\n");
208 		error = -ENOMEM;
209 		goto err2;
210 	}
211 
212 	input = priv->input;
213 	input->evbit[0] = BIT_MASK(EV_KEY);
214 
215 	input->name = pdev->name;
216 	input->phys = "sh-keysc-keys/input0";
217 	input->dev.parent = &pdev->dev;
218 
219 	input->id.bustype = BUS_HOST;
220 	input->id.vendor = 0x0001;
221 	input->id.product = 0x0001;
222 	input->id.version = 0x0100;
223 
224 	input->keycode = pdata->keycodes;
225 	input->keycodesize = sizeof(pdata->keycodes[0]);
226 	input->keycodemax = ARRAY_SIZE(pdata->keycodes);
227 
228 	error = request_threaded_irq(irq, NULL, sh_keysc_isr, IRQF_ONESHOT,
229 				     dev_name(&pdev->dev), pdev);
230 	if (error) {
231 		dev_err(&pdev->dev, "failed to request IRQ\n");
232 		goto err3;
233 	}
234 
235 	for (i = 0; i < SH_KEYSC_MAXKEYS; i++)
236 		__set_bit(pdata->keycodes[i], input->keybit);
237 	__clear_bit(KEY_RESERVED, input->keybit);
238 
239 	error = input_register_device(input);
240 	if (error) {
241 		dev_err(&pdev->dev, "failed to register input device\n");
242 		goto err4;
243 	}
244 
245 	pm_runtime_enable(&pdev->dev);
246 	pm_runtime_get_sync(&pdev->dev);
247 
248 	sh_keysc_write(priv, KYCR1, (sh_keysc_mode[pdata->mode].kymd << 8) |
249 		       pdata->scan_timing);
250 	sh_keysc_level_mode(priv, 0);
251 
252 	device_init_wakeup(&pdev->dev, 1);
253 
254 	return 0;
255 
256  err4:
257 	free_irq(irq, pdev);
258  err3:
259 	input_free_device(input);
260  err2:
261 	iounmap(priv->iomem_base);
262  err1:
263 	kfree(priv);
264  err0:
265 	return error;
266 }
267 
268 static int sh_keysc_remove(struct platform_device *pdev)
269 {
270 	struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
271 
272 	sh_keysc_write(priv, KYCR2, KYCR2_IRQ_DISABLED);
273 
274 	input_unregister_device(priv->input);
275 	free_irq(platform_get_irq(pdev, 0), pdev);
276 	iounmap(priv->iomem_base);
277 
278 	pm_runtime_put_sync(&pdev->dev);
279 	pm_runtime_disable(&pdev->dev);
280 
281 	kfree(priv);
282 
283 	return 0;
284 }
285 
286 static int sh_keysc_suspend(struct device *dev)
287 {
288 	struct platform_device *pdev = to_platform_device(dev);
289 	struct sh_keysc_priv *priv = platform_get_drvdata(pdev);
290 	int irq = platform_get_irq(pdev, 0);
291 	unsigned short value;
292 
293 	value = sh_keysc_read(priv, KYCR1);
294 
295 	if (device_may_wakeup(dev)) {
296 		sh_keysc_write(priv, KYCR1, value | 0x80);
297 		enable_irq_wake(irq);
298 	} else {
299 		sh_keysc_write(priv, KYCR1, value & ~0x80);
300 		pm_runtime_put_sync(dev);
301 	}
302 
303 	return 0;
304 }
305 
306 static int sh_keysc_resume(struct device *dev)
307 {
308 	struct platform_device *pdev = to_platform_device(dev);
309 	int irq = platform_get_irq(pdev, 0);
310 
311 	if (device_may_wakeup(dev))
312 		disable_irq_wake(irq);
313 	else
314 		pm_runtime_get_sync(dev);
315 
316 	return 0;
317 }
318 
319 static DEFINE_SIMPLE_DEV_PM_OPS(sh_keysc_dev_pm_ops,
320 				sh_keysc_suspend, sh_keysc_resume);
321 
322 static struct platform_driver sh_keysc_device_driver = {
323 	.probe		= sh_keysc_probe,
324 	.remove		= sh_keysc_remove,
325 	.driver		= {
326 		.name	= "sh_keysc",
327 		.pm	= pm_sleep_ptr(&sh_keysc_dev_pm_ops),
328 	}
329 };
330 module_platform_driver(sh_keysc_device_driver);
331 
332 MODULE_AUTHOR("Magnus Damm");
333 MODULE_DESCRIPTION("SuperH KEYSC Keypad Driver");
334 MODULE_LICENSE("GPL");
335