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
29struct 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
46static 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
55static 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
68static 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
99static 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
120static 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
128static void bfin_rotary_free_action(void *data)
129{
130	peripheral_free_list(data);
131}
132
133static 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(&pdev->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(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			peripheral_free_list(pdata->pin_list);
163			return error;
164		}
165	}
166
167	rotary = devm_kzalloc(dev, sizeof(struct bfin_rot), GFP_KERNEL);
168	if (!rotary)
169		return -ENOMEM;
170
171	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
172	rotary->base = devm_ioremap_resource(dev, res);
173	if (IS_ERR(rotary->base))
174		return PTR_ERR(rotary->base);
175
176	input = devm_input_allocate_device(dev);
177	if (!input)
178		return -ENOMEM;
179
180	rotary->input = input;
181
182	rotary->up_key = pdata->rotary_up_key;
183	rotary->down_key = pdata->rotary_down_key;
184	rotary->button_key = pdata->rotary_button_key;
185	rotary->rel_code = pdata->rotary_rel_code;
186
187	rotary->mode = pdata->mode;
188	rotary->debounce = pdata->debounce;
189
190	input->name = pdev->name;
191	input->phys = "bfin-rotary/input0";
192	input->dev.parent = &pdev->dev;
193
194	input_set_drvdata(input, rotary);
195
196	input->id.bustype = BUS_HOST;
197	input->id.vendor = 0x0001;
198	input->id.product = 0x0001;
199	input->id.version = 0x0100;
200
201	input->open = bfin_rotary_open;
202	input->close = bfin_rotary_close;
203
204	if (rotary->up_key) {
205		__set_bit(EV_KEY, input->evbit);
206		__set_bit(rotary->up_key, input->keybit);
207		__set_bit(rotary->down_key, input->keybit);
208	} else {
209		__set_bit(EV_REL, input->evbit);
210		__set_bit(rotary->rel_code, input->relbit);
211	}
212
213	if (rotary->button_key) {
214		__set_bit(EV_KEY, input->evbit);
215		__set_bit(rotary->button_key, input->keybit);
216	}
217
218	/* Quiesce the device before requesting irq */
219	bfin_rotary_close(input);
220
221	rotary->irq = platform_get_irq(pdev, 0);
222	if (rotary->irq < 0) {
223		dev_err(dev, "No rotary IRQ specified\n");
224		return -ENOENT;
225	}
226
227	error = devm_request_irq(dev, rotary->irq, bfin_rotary_isr,
228				 0, dev_name(dev), rotary);
229	if (error) {
230		dev_err(dev, "unable to claim irq %d; error %d\n",
231			rotary->irq, error);
232		return error;
233	}
234
235	error = input_register_device(input);
236	if (error) {
237		dev_err(dev, "unable to register input device (%d)\n", error);
238		return error;
239	}
240
241	platform_set_drvdata(pdev, rotary);
242	device_init_wakeup(&pdev->dev, 1);
243
244	return 0;
245}
246
247static int __maybe_unused bfin_rotary_suspend(struct device *dev)
248{
249	struct platform_device *pdev = to_platform_device(dev);
250	struct bfin_rot *rotary = platform_get_drvdata(pdev);
251
252	rotary->cnt_config = readw(rotary->base + CNT_CONFIG_OFF);
253	rotary->cnt_imask = readw(rotary->base + CNT_IMASK_OFF);
254	rotary->cnt_debounce = readw(rotary->base + CNT_DEBOUNCE_OFF);
255
256	if (device_may_wakeup(&pdev->dev))
257		enable_irq_wake(rotary->irq);
258
259	return 0;
260}
261
262static int __maybe_unused bfin_rotary_resume(struct device *dev)
263{
264	struct platform_device *pdev = to_platform_device(dev);
265	struct bfin_rot *rotary = platform_get_drvdata(pdev);
266
267	writew(rotary->cnt_debounce, rotary->base + CNT_DEBOUNCE_OFF);
268	writew(rotary->cnt_imask, rotary->base + CNT_IMASK_OFF);
269	writew(rotary->cnt_config & ~CNTE, rotary->base + CNT_CONFIG_OFF);
270
271	if (device_may_wakeup(&pdev->dev))
272		disable_irq_wake(rotary->irq);
273
274	if (rotary->cnt_config & CNTE)
275		writew(rotary->cnt_config, rotary->base + CNT_CONFIG_OFF);
276
277	return 0;
278}
279
280static SIMPLE_DEV_PM_OPS(bfin_rotary_pm_ops,
281			 bfin_rotary_suspend, bfin_rotary_resume);
282
283static struct platform_driver bfin_rotary_device_driver = {
284	.probe		= bfin_rotary_probe,
285	.driver		= {
286		.name	= "bfin-rotary",
287		.pm	= &bfin_rotary_pm_ops,
288	},
289};
290module_platform_driver(bfin_rotary_device_driver);
291
292MODULE_LICENSE("GPL");
293MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
294MODULE_DESCRIPTION("Rotary Counter driver for Blackfin Processors");
295MODULE_ALIAS("platform:bfin-rotary");
296