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1/*
2 * VTI CMA3000_D0x Accelerometer driver
3 *
4 * Copyright (C) 2010 Texas Instruments
5 * Author: Hemanth V <hemanthv@ti.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 as published by
9 * the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/types.h>
21#include <linux/interrupt.h>
22#include <linux/delay.h>
23#include <linux/slab.h>
24#include <linux/input.h>
25#include <linux/input/cma3000.h>
26#include <linux/module.h>
27
28#include "cma3000_d0x.h"
29
30#define CMA3000_WHOAMI      0x00
31#define CMA3000_REVID       0x01
32#define CMA3000_CTRL        0x02
33#define CMA3000_STATUS      0x03
34#define CMA3000_RSTR        0x04
35#define CMA3000_INTSTATUS   0x05
36#define CMA3000_DOUTX       0x06
37#define CMA3000_DOUTY       0x07
38#define CMA3000_DOUTZ       0x08
39#define CMA3000_MDTHR       0x09
40#define CMA3000_MDFFTMR     0x0A
41#define CMA3000_FFTHR       0x0B
42
43#define CMA3000_RANGE2G    (1 << 7)
44#define CMA3000_RANGE8G    (0 << 7)
45#define CMA3000_BUSI2C     (0 << 4)
46#define CMA3000_MODEMASK   (7 << 1)
47#define CMA3000_GRANGEMASK (1 << 7)
48
49#define CMA3000_STATUS_PERR    1
50#define CMA3000_INTSTATUS_FFDET (1 << 2)
51
52/* Settling time delay in ms */
53#define CMA3000_SETDELAY    30
54
55/* Delay for clearing interrupt in us */
56#define CMA3000_INTDELAY    44
57
58
59/*
60 * Bit weights in mg for bit 0, other bits need
61 * multiply factor 2^n. Eight bit is the sign bit.
62 */
63#define BIT_TO_2G  18
64#define BIT_TO_8G  71
65
66struct cma3000_accl_data {
67	const struct cma3000_bus_ops *bus_ops;
68	const struct cma3000_platform_data *pdata;
69
70	struct device *dev;
71	struct input_dev *input_dev;
72
73	int bit_to_mg;
74	int irq;
75
76	int g_range;
77	u8 mode;
78
79	struct mutex mutex;
80	bool opened;
81	bool suspended;
82};
83
84#define CMA3000_READ(data, reg, msg) \
85	(data->bus_ops->read(data->dev, reg, msg))
86#define CMA3000_SET(data, reg, val, msg) \
87	((data)->bus_ops->write(data->dev, reg, val, msg))
88
89/*
90 * Conversion for each of the eight modes to g, depending
91 * on G range i.e 2G or 8G. Some modes always operate in
92 * 8G.
93 */
94
95static int mode_to_mg[8][2] = {
96	{ 0, 0 },
97	{ BIT_TO_8G, BIT_TO_2G },
98	{ BIT_TO_8G, BIT_TO_2G },
99	{ BIT_TO_8G, BIT_TO_8G },
100	{ BIT_TO_8G, BIT_TO_8G },
101	{ BIT_TO_8G, BIT_TO_2G },
102	{ BIT_TO_8G, BIT_TO_2G },
103	{ 0, 0},
104};
105
106static void decode_mg(struct cma3000_accl_data *data, int *datax,
107				int *datay, int *dataz)
108{
109	/* Data in 2's complement, convert to mg */
110	*datax = ((s8)*datax) * data->bit_to_mg;
111	*datay = ((s8)*datay) * data->bit_to_mg;
112	*dataz = ((s8)*dataz) * data->bit_to_mg;
113}
114
115static irqreturn_t cma3000_thread_irq(int irq, void *dev_id)
116{
117	struct cma3000_accl_data *data = dev_id;
118	int datax, datay, dataz, intr_status;
119	u8 ctrl, mode, range;
120
121	intr_status = CMA3000_READ(data, CMA3000_INTSTATUS, "interrupt status");
122	if (intr_status < 0)
123		return IRQ_NONE;
124
125	/* Check if free fall is detected, report immediately */
126	if (intr_status & CMA3000_INTSTATUS_FFDET) {
127		input_report_abs(data->input_dev, ABS_MISC, 1);
128		input_sync(data->input_dev);
129	} else {
130		input_report_abs(data->input_dev, ABS_MISC, 0);
131	}
132
133	datax = CMA3000_READ(data, CMA3000_DOUTX, "X");
134	datay = CMA3000_READ(data, CMA3000_DOUTY, "Y");
135	dataz = CMA3000_READ(data, CMA3000_DOUTZ, "Z");
136
137	ctrl = CMA3000_READ(data, CMA3000_CTRL, "ctrl");
138	mode = (ctrl & CMA3000_MODEMASK) >> 1;
139	range = (ctrl & CMA3000_GRANGEMASK) >> 7;
140
141	data->bit_to_mg = mode_to_mg[mode][range];
142
143	/* Interrupt not for this device */
144	if (data->bit_to_mg == 0)
145		return IRQ_NONE;
146
147	/* Decode register values to milli g */
148	decode_mg(data, &datax, &datay, &dataz);
149
150	input_report_abs(data->input_dev, ABS_X, datax);
151	input_report_abs(data->input_dev, ABS_Y, datay);
152	input_report_abs(data->input_dev, ABS_Z, dataz);
153	input_sync(data->input_dev);
154
155	return IRQ_HANDLED;
156}
157
158static int cma3000_reset(struct cma3000_accl_data *data)
159{
160	int val;
161
162	/* Reset sequence */
163	CMA3000_SET(data, CMA3000_RSTR, 0x02, "Reset");
164	CMA3000_SET(data, CMA3000_RSTR, 0x0A, "Reset");
165	CMA3000_SET(data, CMA3000_RSTR, 0x04, "Reset");
166
167	/* Settling time delay */
168	mdelay(10);
169
170	val = CMA3000_READ(data, CMA3000_STATUS, "Status");
171	if (val < 0) {
172		dev_err(data->dev, "Reset failed\n");
173		return val;
174	}
175
176	if (val & CMA3000_STATUS_PERR) {
177		dev_err(data->dev, "Parity Error\n");
178		return -EIO;
179	}
180
181	return 0;
182}
183
184static int cma3000_poweron(struct cma3000_accl_data *data)
185{
186	const struct cma3000_platform_data *pdata = data->pdata;
187	u8 ctrl = 0;
188	int ret;
189
190	if (data->g_range == CMARANGE_2G) {
191		ctrl = (data->mode << 1) | CMA3000_RANGE2G;
192	} else if (data->g_range == CMARANGE_8G) {
193		ctrl = (data->mode << 1) | CMA3000_RANGE8G;
194	} else {
195		dev_info(data->dev,
196			 "Invalid G range specified, assuming 8G\n");
197		ctrl = (data->mode << 1) | CMA3000_RANGE8G;
198	}
199
200	ctrl |= data->bus_ops->ctrl_mod;
201
202	CMA3000_SET(data, CMA3000_MDTHR, pdata->mdthr,
203		    "Motion Detect Threshold");
204	CMA3000_SET(data, CMA3000_MDFFTMR, pdata->mdfftmr,
205		    "Time register");
206	CMA3000_SET(data, CMA3000_FFTHR, pdata->ffthr,
207		    "Free fall threshold");
208	ret = CMA3000_SET(data, CMA3000_CTRL, ctrl, "Mode setting");
209	if (ret < 0)
210		return -EIO;
211
212	msleep(CMA3000_SETDELAY);
213
214	return 0;
215}
216
217static int cma3000_poweroff(struct cma3000_accl_data *data)
218{
219	int ret;
220
221	ret = CMA3000_SET(data, CMA3000_CTRL, CMAMODE_POFF, "Mode setting");
222	msleep(CMA3000_SETDELAY);
223
224	return ret;
225}
226
227static int cma3000_open(struct input_dev *input_dev)
228{
229	struct cma3000_accl_data *data = input_get_drvdata(input_dev);
230
231	mutex_lock(&data->mutex);
232
233	if (!data->suspended)
234		cma3000_poweron(data);
235
236	data->opened = true;
237
238	mutex_unlock(&data->mutex);
239
240	return 0;
241}
242
243static void cma3000_close(struct input_dev *input_dev)
244{
245	struct cma3000_accl_data *data = input_get_drvdata(input_dev);
246
247	mutex_lock(&data->mutex);
248
249	if (!data->suspended)
250		cma3000_poweroff(data);
251
252	data->opened = false;
253
254	mutex_unlock(&data->mutex);
255}
256
257void cma3000_suspend(struct cma3000_accl_data *data)
258{
259	mutex_lock(&data->mutex);
260
261	if (!data->suspended && data->opened)
262		cma3000_poweroff(data);
263
264	data->suspended = true;
265
266	mutex_unlock(&data->mutex);
267}
268EXPORT_SYMBOL(cma3000_suspend);
269
270
271void cma3000_resume(struct cma3000_accl_data *data)
272{
273	mutex_lock(&data->mutex);
274
275	if (data->suspended && data->opened)
276		cma3000_poweron(data);
277
278	data->suspended = false;
279
280	mutex_unlock(&data->mutex);
281}
282EXPORT_SYMBOL(cma3000_resume);
283
284struct cma3000_accl_data *cma3000_init(struct device *dev, int irq,
285				       const struct cma3000_bus_ops *bops)
286{
287	const struct cma3000_platform_data *pdata = dev_get_platdata(dev);
288	struct cma3000_accl_data *data;
289	struct input_dev *input_dev;
290	int rev;
291	int error;
292
293	if (!pdata) {
294		dev_err(dev, "platform data not found\n");
295		error = -EINVAL;
296		goto err_out;
297	}
298
299
300	/* if no IRQ return error */
301	if (irq == 0) {
302		error = -EINVAL;
303		goto err_out;
304	}
305
306	data = kzalloc(sizeof(struct cma3000_accl_data), GFP_KERNEL);
307	input_dev = input_allocate_device();
308	if (!data || !input_dev) {
309		error = -ENOMEM;
310		goto err_free_mem;
311	}
312
313	data->dev = dev;
314	data->input_dev = input_dev;
315	data->bus_ops = bops;
316	data->pdata = pdata;
317	data->irq = irq;
318	mutex_init(&data->mutex);
319
320	data->mode = pdata->mode;
321	if (data->mode > CMAMODE_POFF) {
322		data->mode = CMAMODE_MOTDET;
323		dev_warn(dev,
324			 "Invalid mode specified, assuming Motion Detect\n");
325	}
326
327	data->g_range = pdata->g_range;
328	if (data->g_range != CMARANGE_2G && data->g_range != CMARANGE_8G) {
329		dev_info(dev,
330			 "Invalid G range specified, assuming 8G\n");
331		data->g_range = CMARANGE_8G;
332	}
333
334	input_dev->name = "cma3000-accelerometer";
335	input_dev->id.bustype = bops->bustype;
336	input_dev->open = cma3000_open;
337	input_dev->close = cma3000_close;
338
339	 __set_bit(EV_ABS, input_dev->evbit);
340
341	input_set_abs_params(input_dev, ABS_X,
342			-data->g_range, data->g_range, pdata->fuzz_x, 0);
343	input_set_abs_params(input_dev, ABS_Y,
344			-data->g_range, data->g_range, pdata->fuzz_y, 0);
345	input_set_abs_params(input_dev, ABS_Z,
346			-data->g_range, data->g_range, pdata->fuzz_z, 0);
347	input_set_abs_params(input_dev, ABS_MISC, 0, 1, 0, 0);
348
349	input_set_drvdata(input_dev, data);
350
351	error = cma3000_reset(data);
352	if (error)
353		goto err_free_mem;
354
355	rev = CMA3000_READ(data, CMA3000_REVID, "Revid");
356	if (rev < 0) {
357		error = rev;
358		goto err_free_mem;
359	}
360
361	pr_info("CMA3000 Accelerometer: Revision %x\n", rev);
362
363	error = request_threaded_irq(irq, NULL, cma3000_thread_irq,
364				     pdata->irqflags | IRQF_ONESHOT,
365				     "cma3000_d0x", data);
366	if (error) {
367		dev_err(dev, "request_threaded_irq failed\n");
368		goto err_free_mem;
369	}
370
371	error = input_register_device(data->input_dev);
372	if (error) {
373		dev_err(dev, "Unable to register input device\n");
374		goto err_free_irq;
375	}
376
377	return data;
378
379err_free_irq:
380	free_irq(irq, data);
381err_free_mem:
382	input_free_device(input_dev);
383	kfree(data);
384err_out:
385	return ERR_PTR(error);
386}
387EXPORT_SYMBOL(cma3000_init);
388
389void cma3000_exit(struct cma3000_accl_data *data)
390{
391	free_irq(data->irq, data);
392	input_unregister_device(data->input_dev);
393	kfree(data);
394}
395EXPORT_SYMBOL(cma3000_exit);
396
397MODULE_DESCRIPTION("CMA3000-D0x Accelerometer Driver");
398MODULE_LICENSE("GPL");
399MODULE_AUTHOR("Hemanth V <hemanthv@ti.com>");
400