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1 /*
2  * Rotary counter driver for Analog Devices Blackfin Processors
3  *
4  * Copyright 2008-2009 Analog Devices Inc.
5  * Licensed under the GPL-2 or later.
6  */
7 
8 #include <linux/module.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/irq.h>
12 #include <linux/pm.h>
13 #include <linux/platform_device.h>
14 #include <linux/input.h>
15 #include <linux/slab.h>
16 #include <linux/platform_data/bfin_rotary.h>
17 
18 #include <asm/portmux.h>
19 
20 #define CNT_CONFIG_OFF		0	/* CNT Config Offset */
21 #define CNT_IMASK_OFF		4	/* CNT Interrupt Mask Offset */
22 #define CNT_STATUS_OFF		8	/* CNT Status Offset */
23 #define CNT_COMMAND_OFF		12	/* CNT Command Offset */
24 #define CNT_DEBOUNCE_OFF	16	/* CNT Debounce Offset */
25 #define CNT_COUNTER_OFF		20	/* CNT Counter Offset */
26 #define CNT_MAX_OFF		24	/* CNT Maximum Count Offset */
27 #define CNT_MIN_OFF		28	/* CNT Minimum Count Offset */
28 
29 struct bfin_rot {
30 	struct input_dev *input;
31 	void __iomem *base;
32 	int irq;
33 	unsigned int up_key;
34 	unsigned int down_key;
35 	unsigned int button_key;
36 	unsigned int rel_code;
37 
38 	unsigned short mode;
39 	unsigned short debounce;
40 
41 	unsigned short cnt_config;
42 	unsigned short cnt_imask;
43 	unsigned short cnt_debounce;
44 };
45 
report_key_event(struct input_dev * input,int keycode)46 static void report_key_event(struct input_dev *input, int keycode)
47 {
48 	/* simulate a press-n-release */
49 	input_report_key(input, keycode, 1);
50 	input_sync(input);
51 	input_report_key(input, keycode, 0);
52 	input_sync(input);
53 }
54 
report_rotary_event(struct bfin_rot * rotary,int delta)55 static void report_rotary_event(struct bfin_rot *rotary, int delta)
56 {
57 	struct input_dev *input = rotary->input;
58 
59 	if (rotary->up_key) {
60 		report_key_event(input,
61 				 delta > 0 ? rotary->up_key : rotary->down_key);
62 	} else {
63 		input_report_rel(input, rotary->rel_code, delta);
64 		input_sync(input);
65 	}
66 }
67 
bfin_rotary_isr(int irq,void * dev_id)68 static irqreturn_t bfin_rotary_isr(int irq, void *dev_id)
69 {
70 	struct bfin_rot *rotary = dev_id;
71 	int delta;
72 
73 	switch (readw(rotary->base + CNT_STATUS_OFF)) {
74 
75 	case ICII:
76 		break;
77 
78 	case UCII:
79 	case DCII:
80 		delta = readl(rotary->base + CNT_COUNTER_OFF);
81 		if (delta)
82 			report_rotary_event(rotary, delta);
83 		break;
84 
85 	case CZMII:
86 		report_key_event(rotary->input, rotary->button_key);
87 		break;
88 
89 	default:
90 		break;
91 	}
92 
93 	writew(W1LCNT_ZERO, rotary->base + CNT_COMMAND_OFF); /* Clear COUNTER */
94 	writew(-1, rotary->base + CNT_STATUS_OFF); /* Clear STATUS */
95 
96 	return IRQ_HANDLED;
97 }
98 
bfin_rotary_open(struct input_dev * input)99 static int bfin_rotary_open(struct input_dev *input)
100 {
101 	struct bfin_rot *rotary = input_get_drvdata(input);
102 	unsigned short val;
103 
104 	if (rotary->mode & ROT_DEBE)
105 		writew(rotary->debounce & DPRESCALE,
106 			rotary->base + CNT_DEBOUNCE_OFF);
107 
108 	writew(rotary->mode & ~CNTE, rotary->base + CNT_CONFIG_OFF);
109 
110 	val = UCIE | DCIE;
111 	if (rotary->button_key)
112 		val |= CZMIE;
113 	writew(val, rotary->base + CNT_IMASK_OFF);
114 
115 	writew(rotary->mode | CNTE, rotary->base + CNT_CONFIG_OFF);
116 
117 	return 0;
118 }
119 
bfin_rotary_close(struct input_dev * input)120 static void bfin_rotary_close(struct input_dev *input)
121 {
122 	struct bfin_rot *rotary = input_get_drvdata(input);
123 
124 	writew(0, rotary->base + CNT_CONFIG_OFF);
125 	writew(0, rotary->base + CNT_IMASK_OFF);
126 }
127 
bfin_rotary_free_action(void * data)128 static void bfin_rotary_free_action(void *data)
129 {
130 	peripheral_free_list(data);
131 }
132 
bfin_rotary_probe(struct platform_device * pdev)133 static int bfin_rotary_probe(struct platform_device *pdev)
134 {
135 	struct device *dev = &pdev->dev;
136 	const struct bfin_rotary_platform_data *pdata = dev_get_platdata(dev);
137 	struct bfin_rot *rotary;
138 	struct resource *res;
139 	struct input_dev *input;
140 	int error;
141 
142 	/* Basic validation */
143 	if ((pdata->rotary_up_key && !pdata->rotary_down_key) ||
144 	    (!pdata->rotary_up_key && pdata->rotary_down_key)) {
145 		return -EINVAL;
146 	}
147 
148 	if (pdata->pin_list) {
149 		error = peripheral_request_list(pdata->pin_list,
150 						dev_name(dev));
151 		if (error) {
152 			dev_err(dev, "requesting peripherals failed: %d\n",
153 				error);
154 			return error;
155 		}
156 
157 		error = devm_add_action_or_reset(dev, bfin_rotary_free_action,
158 						 pdata->pin_list);
159 		if (error) {
160 			dev_err(dev, "setting cleanup action failed: %d\n",
161 				error);
162 			return error;
163 		}
164 	}
165 
166 	rotary = devm_kzalloc(dev, sizeof(struct bfin_rot), GFP_KERNEL);
167 	if (!rotary)
168 		return -ENOMEM;
169 
170 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
171 	rotary->base = devm_ioremap_resource(dev, res);
172 	if (IS_ERR(rotary->base))
173 		return PTR_ERR(rotary->base);
174 
175 	input = devm_input_allocate_device(dev);
176 	if (!input)
177 		return -ENOMEM;
178 
179 	rotary->input = input;
180 
181 	rotary->up_key = pdata->rotary_up_key;
182 	rotary->down_key = pdata->rotary_down_key;
183 	rotary->button_key = pdata->rotary_button_key;
184 	rotary->rel_code = pdata->rotary_rel_code;
185 
186 	rotary->mode = pdata->mode;
187 	rotary->debounce = pdata->debounce;
188 
189 	input->name = pdev->name;
190 	input->phys = "bfin-rotary/input0";
191 	input->dev.parent = dev;
192 
193 	input_set_drvdata(input, rotary);
194 
195 	input->id.bustype = BUS_HOST;
196 	input->id.vendor = 0x0001;
197 	input->id.product = 0x0001;
198 	input->id.version = 0x0100;
199 
200 	input->open = bfin_rotary_open;
201 	input->close = bfin_rotary_close;
202 
203 	if (rotary->up_key) {
204 		__set_bit(EV_KEY, input->evbit);
205 		__set_bit(rotary->up_key, input->keybit);
206 		__set_bit(rotary->down_key, input->keybit);
207 	} else {
208 		__set_bit(EV_REL, input->evbit);
209 		__set_bit(rotary->rel_code, input->relbit);
210 	}
211 
212 	if (rotary->button_key) {
213 		__set_bit(EV_KEY, input->evbit);
214 		__set_bit(rotary->button_key, input->keybit);
215 	}
216 
217 	/* Quiesce the device before requesting irq */
218 	bfin_rotary_close(input);
219 
220 	rotary->irq = platform_get_irq(pdev, 0);
221 	if (rotary->irq < 0) {
222 		dev_err(dev, "No rotary IRQ specified\n");
223 		return -ENOENT;
224 	}
225 
226 	error = devm_request_irq(dev, rotary->irq, bfin_rotary_isr,
227 				 0, dev_name(dev), rotary);
228 	if (error) {
229 		dev_err(dev, "unable to claim irq %d; error %d\n",
230 			rotary->irq, error);
231 		return error;
232 	}
233 
234 	error = input_register_device(input);
235 	if (error) {
236 		dev_err(dev, "unable to register input device (%d)\n", error);
237 		return error;
238 	}
239 
240 	platform_set_drvdata(pdev, rotary);
241 	device_init_wakeup(dev, 1);
242 
243 	return 0;
244 }
245 
bfin_rotary_suspend(struct device * dev)246 static int __maybe_unused bfin_rotary_suspend(struct device *dev)
247 {
248 	struct platform_device *pdev = to_platform_device(dev);
249 	struct bfin_rot *rotary = platform_get_drvdata(pdev);
250 
251 	rotary->cnt_config = readw(rotary->base + CNT_CONFIG_OFF);
252 	rotary->cnt_imask = readw(rotary->base + CNT_IMASK_OFF);
253 	rotary->cnt_debounce = readw(rotary->base + CNT_DEBOUNCE_OFF);
254 
255 	if (device_may_wakeup(&pdev->dev))
256 		enable_irq_wake(rotary->irq);
257 
258 	return 0;
259 }
260 
bfin_rotary_resume(struct device * dev)261 static int __maybe_unused bfin_rotary_resume(struct device *dev)
262 {
263 	struct platform_device *pdev = to_platform_device(dev);
264 	struct bfin_rot *rotary = platform_get_drvdata(pdev);
265 
266 	writew(rotary->cnt_debounce, rotary->base + CNT_DEBOUNCE_OFF);
267 	writew(rotary->cnt_imask, rotary->base + CNT_IMASK_OFF);
268 	writew(rotary->cnt_config & ~CNTE, rotary->base + CNT_CONFIG_OFF);
269 
270 	if (device_may_wakeup(&pdev->dev))
271 		disable_irq_wake(rotary->irq);
272 
273 	if (rotary->cnt_config & CNTE)
274 		writew(rotary->cnt_config, rotary->base + CNT_CONFIG_OFF);
275 
276 	return 0;
277 }
278 
279 static SIMPLE_DEV_PM_OPS(bfin_rotary_pm_ops,
280 			 bfin_rotary_suspend, bfin_rotary_resume);
281 
282 static struct platform_driver bfin_rotary_device_driver = {
283 	.probe		= bfin_rotary_probe,
284 	.driver		= {
285 		.name	= "bfin-rotary",
286 		.pm	= &bfin_rotary_pm_ops,
287 	},
288 };
289 module_platform_driver(bfin_rotary_device_driver);
290 
291 MODULE_LICENSE("GPL");
292 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
293 MODULE_DESCRIPTION("Rotary Counter driver for Blackfin Processors");
294 MODULE_ALIAS("platform:bfin-rotary");
295