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/init.h>
 10#include <linux/interrupt.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
 17#include <asm/portmux.h>
 18#include <asm/bfin_rotary.h>
 19
 20static const u16 per_cnt[] = {
 21	P_CNT_CUD,
 22	P_CNT_CDG,
 23	P_CNT_CZM,
 24	0
 25};
 26
 27struct bfin_rot {
 28	struct input_dev *input;
 29	int irq;
 30	unsigned int up_key;
 31	unsigned int down_key;
 32	unsigned int button_key;
 33	unsigned int rel_code;
 34	unsigned short cnt_config;
 35	unsigned short cnt_imask;
 36	unsigned short cnt_debounce;
 37};
 38
 39static void report_key_event(struct input_dev *input, int keycode)
 40{
 41	/* simulate a press-n-release */
 42	input_report_key(input, keycode, 1);
 43	input_sync(input);
 44	input_report_key(input, keycode, 0);
 45	input_sync(input);
 46}
 47
 48static void report_rotary_event(struct bfin_rot *rotary, int delta)
 49{
 50	struct input_dev *input = rotary->input;
 51
 52	if (rotary->up_key) {
 53		report_key_event(input,
 54				 delta > 0 ? rotary->up_key : rotary->down_key);
 55	} else {
 56		input_report_rel(input, rotary->rel_code, delta);
 57		input_sync(input);
 58	}
 59}
 60
 61static irqreturn_t bfin_rotary_isr(int irq, void *dev_id)
 62{
 63	struct platform_device *pdev = dev_id;
 64	struct bfin_rot *rotary = platform_get_drvdata(pdev);
 65	int delta;
 66
 67	switch (bfin_read_CNT_STATUS()) {
 68
 69	case ICII:
 70		break;
 71
 72	case UCII:
 73	case DCII:
 74		delta = bfin_read_CNT_COUNTER();
 75		if (delta)
 76			report_rotary_event(rotary, delta);
 77		break;
 78
 79	case CZMII:
 80		report_key_event(rotary->input, rotary->button_key);
 81		break;
 82
 83	default:
 84		break;
 85	}
 86
 87	bfin_write_CNT_COMMAND(W1LCNT_ZERO);	/* Clear COUNTER */
 88	bfin_write_CNT_STATUS(-1);	/* Clear STATUS */
 89
 90	return IRQ_HANDLED;
 91}
 92
 93static int __devinit bfin_rotary_probe(struct platform_device *pdev)
 94{
 95	struct bfin_rotary_platform_data *pdata = pdev->dev.platform_data;
 96	struct bfin_rot *rotary;
 97	struct input_dev *input;
 98	int error;
 99
100	/* Basic validation */
101	if ((pdata->rotary_up_key && !pdata->rotary_down_key) ||
102	    (!pdata->rotary_up_key && pdata->rotary_down_key)) {
103		return -EINVAL;
104	}
105
106	error = peripheral_request_list(per_cnt, dev_name(&pdev->dev));
107	if (error) {
108		dev_err(&pdev->dev, "requesting peripherals failed\n");
109		return error;
110	}
111
112	rotary = kzalloc(sizeof(struct bfin_rot), GFP_KERNEL);
113	input = input_allocate_device();
114	if (!rotary || !input) {
115		error = -ENOMEM;
116		goto out1;
117	}
118
119	rotary->input = input;
120
121	rotary->up_key = pdata->rotary_up_key;
122	rotary->down_key = pdata->rotary_down_key;
123	rotary->button_key = pdata->rotary_button_key;
124	rotary->rel_code = pdata->rotary_rel_code;
125
126	error = rotary->irq = platform_get_irq(pdev, 0);
127	if (error < 0)
128		goto out1;
129
130	input->name = pdev->name;
131	input->phys = "bfin-rotary/input0";
132	input->dev.parent = &pdev->dev;
133
134	input_set_drvdata(input, rotary);
135
136	input->id.bustype = BUS_HOST;
137	input->id.vendor = 0x0001;
138	input->id.product = 0x0001;
139	input->id.version = 0x0100;
140
141	if (rotary->up_key) {
142		__set_bit(EV_KEY, input->evbit);
143		__set_bit(rotary->up_key, input->keybit);
144		__set_bit(rotary->down_key, input->keybit);
145	} else {
146		__set_bit(EV_REL, input->evbit);
147		__set_bit(rotary->rel_code, input->relbit);
148	}
149
150	if (rotary->button_key) {
151		__set_bit(EV_KEY, input->evbit);
152		__set_bit(rotary->button_key, input->keybit);
153	}
154
155	error = request_irq(rotary->irq, bfin_rotary_isr,
156			    0, dev_name(&pdev->dev), pdev);
157	if (error) {
158		dev_err(&pdev->dev,
159			"unable to claim irq %d; error %d\n",
160			rotary->irq, error);
161		goto out1;
162	}
163
164	error = input_register_device(input);
165	if (error) {
166		dev_err(&pdev->dev,
167			"unable to register input device (%d)\n", error);
168		goto out2;
169	}
170
171	if (pdata->rotary_button_key)
172		bfin_write_CNT_IMASK(CZMIE);
173
174	if (pdata->mode & ROT_DEBE)
175		bfin_write_CNT_DEBOUNCE(pdata->debounce & DPRESCALE);
176
177	if (pdata->mode)
178		bfin_write_CNT_CONFIG(bfin_read_CNT_CONFIG() |
179					(pdata->mode & ~CNTE));
180
181	bfin_write_CNT_IMASK(bfin_read_CNT_IMASK() | UCIE | DCIE);
182	bfin_write_CNT_CONFIG(bfin_read_CNT_CONFIG() | CNTE);
183
184	platform_set_drvdata(pdev, rotary);
185	device_init_wakeup(&pdev->dev, 1);
186
187	return 0;
188
189out2:
190	free_irq(rotary->irq, pdev);
191out1:
192	input_free_device(input);
193	kfree(rotary);
194	peripheral_free_list(per_cnt);
195
196	return error;
197}
198
199static int __devexit bfin_rotary_remove(struct platform_device *pdev)
200{
201	struct bfin_rot *rotary = platform_get_drvdata(pdev);
202
203	bfin_write_CNT_CONFIG(0);
204	bfin_write_CNT_IMASK(0);
205
206	free_irq(rotary->irq, pdev);
207	input_unregister_device(rotary->input);
208	peripheral_free_list(per_cnt);
209
210	kfree(rotary);
211	platform_set_drvdata(pdev, NULL);
212
213	return 0;
214}
215
216#ifdef CONFIG_PM
217static int bfin_rotary_suspend(struct device *dev)
218{
219	struct platform_device *pdev = to_platform_device(dev);
220	struct bfin_rot *rotary = platform_get_drvdata(pdev);
221
222	rotary->cnt_config = bfin_read_CNT_CONFIG();
223	rotary->cnt_imask = bfin_read_CNT_IMASK();
224	rotary->cnt_debounce = bfin_read_CNT_DEBOUNCE();
225
226	if (device_may_wakeup(&pdev->dev))
227		enable_irq_wake(rotary->irq);
228
229	return 0;
230}
231
232static int bfin_rotary_resume(struct device *dev)
233{
234	struct platform_device *pdev = to_platform_device(dev);
235	struct bfin_rot *rotary = platform_get_drvdata(pdev);
236
237	bfin_write_CNT_DEBOUNCE(rotary->cnt_debounce);
238	bfin_write_CNT_IMASK(rotary->cnt_imask);
239	bfin_write_CNT_CONFIG(rotary->cnt_config & ~CNTE);
240
241	if (device_may_wakeup(&pdev->dev))
242		disable_irq_wake(rotary->irq);
243
244	if (rotary->cnt_config & CNTE)
245		bfin_write_CNT_CONFIG(rotary->cnt_config);
246
247	return 0;
248}
249
250static const struct dev_pm_ops bfin_rotary_pm_ops = {
251	.suspend	= bfin_rotary_suspend,
252	.resume		= bfin_rotary_resume,
253};
254#endif
255
256static struct platform_driver bfin_rotary_device_driver = {
257	.probe		= bfin_rotary_probe,
258	.remove		= __devexit_p(bfin_rotary_remove),
259	.driver		= {
260		.name	= "bfin-rotary",
261		.owner	= THIS_MODULE,
262#ifdef CONFIG_PM
263		.pm	= &bfin_rotary_pm_ops,
264#endif
265	},
266};
267
268static int __init bfin_rotary_init(void)
269{
270	return platform_driver_register(&bfin_rotary_device_driver);
271}
272module_init(bfin_rotary_init);
273
274static void __exit bfin_rotary_exit(void)
275{
276	platform_driver_unregister(&bfin_rotary_device_driver);
277}
278module_exit(bfin_rotary_exit);
279
280MODULE_LICENSE("GPL");
281MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
282MODULE_DESCRIPTION("Rotary Counter driver for Blackfin Processors");
283MODULE_ALIAS("platform:bfin-rotary");