1 /*
2  * Copyright (c) 2010, 2011 Fabien Marteau <fabien.marteau@armadeus.com>
3  * Sponsored by ARMadeus Systems
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  *
19  * Driver for Austria Microsystems joysticks AS5011
20  *
21  * TODO:
22  *	- Power on the chip when open() and power down when close()
23  *	- Manage power mode
24  */
25 
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/input.h>
29 #include <linux/gpio.h>
30 #include <linux/delay.h>
31 #include <linux/input/as5011.h>
32 #include <linux/slab.h>
33 #include <linux/module.h>
34 
35 #define DRIVER_DESC "Driver for Austria Microsystems AS5011 joystick"
36 #define MODULE_DEVICE_ALIAS "as5011"
37 
38 MODULE_AUTHOR("Fabien Marteau <fabien.marteau@armadeus.com>");
39 MODULE_DESCRIPTION(DRIVER_DESC);
40 MODULE_LICENSE("GPL");
41 
42 /* registers */
43 #define AS5011_CTRL1		0x76
44 #define AS5011_CTRL2		0x75
45 #define AS5011_XP		0x43
46 #define AS5011_XN		0x44
47 #define AS5011_YP		0x53
48 #define AS5011_YN		0x54
49 #define AS5011_X_REG		0x41
50 #define AS5011_Y_REG		0x42
51 #define AS5011_X_RES_INT	0x51
52 #define AS5011_Y_RES_INT	0x52
53 
54 /* CTRL1 bits */
55 #define AS5011_CTRL1_LP_PULSED		0x80
56 #define AS5011_CTRL1_LP_ACTIVE		0x40
57 #define AS5011_CTRL1_LP_CONTINUE	0x20
58 #define AS5011_CTRL1_INT_WUP_EN		0x10
59 #define AS5011_CTRL1_INT_ACT_EN		0x08
60 #define AS5011_CTRL1_EXT_CLK_EN		0x04
61 #define AS5011_CTRL1_SOFT_RST		0x02
62 #define AS5011_CTRL1_DATA_VALID		0x01
63 
64 /* CTRL2 bits */
65 #define AS5011_CTRL2_EXT_SAMPLE_EN	0x08
66 #define AS5011_CTRL2_RC_BIAS_ON		0x04
67 #define AS5011_CTRL2_INV_SPINNING	0x02
68 
69 #define AS5011_MAX_AXIS	80
70 #define AS5011_MIN_AXIS	(-80)
71 #define AS5011_FUZZ	8
72 #define AS5011_FLAT	40
73 
74 struct as5011_device {
75 	struct input_dev *input_dev;
76 	struct i2c_client *i2c_client;
77 	unsigned int button_gpio;
78 	unsigned int button_irq;
79 	unsigned int axis_irq;
80 };
81 
as5011_i2c_write(struct i2c_client * client,uint8_t aregaddr,uint8_t avalue)82 static int as5011_i2c_write(struct i2c_client *client,
83 			    uint8_t aregaddr,
84 			    uint8_t avalue)
85 {
86 	uint8_t data[2] = { aregaddr, avalue };
87 	struct i2c_msg msg = {
88 		client->addr, I2C_M_IGNORE_NAK, 2, (uint8_t *)data
89 	};
90 	int error;
91 
92 	error = i2c_transfer(client->adapter, &msg, 1);
93 	return error < 0 ? error : 0;
94 }
95 
as5011_i2c_read(struct i2c_client * client,uint8_t aregaddr,signed char * value)96 static int as5011_i2c_read(struct i2c_client *client,
97 			   uint8_t aregaddr, signed char *value)
98 {
99 	uint8_t data[2] = { aregaddr };
100 	struct i2c_msg msg_set[2] = {
101 		{ client->addr, I2C_M_REV_DIR_ADDR, 1, (uint8_t *)data },
102 		{ client->addr, I2C_M_RD | I2C_M_NOSTART, 1, (uint8_t *)data }
103 	};
104 	int error;
105 
106 	error = i2c_transfer(client->adapter, msg_set, 2);
107 	if (error < 0)
108 		return error;
109 
110 	*value = data[0] & 0x80 ? -1 * (1 + ~data[0]) : data[0];
111 	return 0;
112 }
113 
as5011_button_interrupt(int irq,void * dev_id)114 static irqreturn_t as5011_button_interrupt(int irq, void *dev_id)
115 {
116 	struct as5011_device *as5011 = dev_id;
117 	int val = gpio_get_value_cansleep(as5011->button_gpio);
118 
119 	input_report_key(as5011->input_dev, BTN_JOYSTICK, !val);
120 	input_sync(as5011->input_dev);
121 
122 	return IRQ_HANDLED;
123 }
124 
as5011_axis_interrupt(int irq,void * dev_id)125 static irqreturn_t as5011_axis_interrupt(int irq, void *dev_id)
126 {
127 	struct as5011_device *as5011 = dev_id;
128 	int error;
129 	signed char x, y;
130 
131 	error = as5011_i2c_read(as5011->i2c_client, AS5011_X_RES_INT, &x);
132 	if (error < 0)
133 		goto out;
134 
135 	error = as5011_i2c_read(as5011->i2c_client, AS5011_Y_RES_INT, &y);
136 	if (error < 0)
137 		goto out;
138 
139 	input_report_abs(as5011->input_dev, ABS_X, x);
140 	input_report_abs(as5011->input_dev, ABS_Y, y);
141 	input_sync(as5011->input_dev);
142 
143 out:
144 	return IRQ_HANDLED;
145 }
146 
as5011_configure_chip(struct as5011_device * as5011,const struct as5011_platform_data * plat_dat)147 static int __devinit as5011_configure_chip(struct as5011_device *as5011,
148 				const struct as5011_platform_data *plat_dat)
149 {
150 	struct i2c_client *client = as5011->i2c_client;
151 	int error;
152 	signed char value;
153 
154 	/* chip soft reset */
155 	error = as5011_i2c_write(client, AS5011_CTRL1,
156 				 AS5011_CTRL1_SOFT_RST);
157 	if (error < 0) {
158 		dev_err(&client->dev, "Soft reset failed\n");
159 		return error;
160 	}
161 
162 	mdelay(10);
163 
164 	error = as5011_i2c_write(client, AS5011_CTRL1,
165 				 AS5011_CTRL1_LP_PULSED |
166 				 AS5011_CTRL1_LP_ACTIVE |
167 				 AS5011_CTRL1_INT_ACT_EN);
168 	if (error < 0) {
169 		dev_err(&client->dev, "Power config failed\n");
170 		return error;
171 	}
172 
173 	error = as5011_i2c_write(client, AS5011_CTRL2,
174 				 AS5011_CTRL2_INV_SPINNING);
175 	if (error < 0) {
176 		dev_err(&client->dev, "Can't invert spinning\n");
177 		return error;
178 	}
179 
180 	/* write threshold */
181 	error = as5011_i2c_write(client, AS5011_XP, plat_dat->xp);
182 	if (error < 0) {
183 		dev_err(&client->dev, "Can't write threshold\n");
184 		return error;
185 	}
186 
187 	error = as5011_i2c_write(client, AS5011_XN, plat_dat->xn);
188 	if (error < 0) {
189 		dev_err(&client->dev, "Can't write threshold\n");
190 		return error;
191 	}
192 
193 	error = as5011_i2c_write(client, AS5011_YP, plat_dat->yp);
194 	if (error < 0) {
195 		dev_err(&client->dev, "Can't write threshold\n");
196 		return error;
197 	}
198 
199 	error = as5011_i2c_write(client, AS5011_YN, plat_dat->yn);
200 	if (error < 0) {
201 		dev_err(&client->dev, "Can't write threshold\n");
202 		return error;
203 	}
204 
205 	/* to free irq gpio in chip */
206 	error = as5011_i2c_read(client, AS5011_X_RES_INT, &value);
207 	if (error < 0) {
208 		dev_err(&client->dev, "Can't read i2c X resolution value\n");
209 		return error;
210 	}
211 
212 	return 0;
213 }
214 
as5011_probe(struct i2c_client * client,const struct i2c_device_id * id)215 static int __devinit as5011_probe(struct i2c_client *client,
216 				const struct i2c_device_id *id)
217 {
218 	const struct as5011_platform_data *plat_data;
219 	struct as5011_device *as5011;
220 	struct input_dev *input_dev;
221 	int irq;
222 	int error;
223 
224 	plat_data = client->dev.platform_data;
225 	if (!plat_data)
226 		return -EINVAL;
227 
228 	if (!plat_data->axis_irq) {
229 		dev_err(&client->dev, "No axis IRQ?\n");
230 		return -EINVAL;
231 	}
232 
233 	if (!i2c_check_functionality(client->adapter,
234 				     I2C_FUNC_PROTOCOL_MANGLING)) {
235 		dev_err(&client->dev,
236 			"need i2c bus that supports protocol mangling\n");
237 		return -ENODEV;
238 	}
239 
240 	as5011 = kmalloc(sizeof(struct as5011_device), GFP_KERNEL);
241 	input_dev = input_allocate_device();
242 	if (!as5011 || !input_dev) {
243 		dev_err(&client->dev,
244 			"Can't allocate memory for device structure\n");
245 		error = -ENOMEM;
246 		goto err_free_mem;
247 	}
248 
249 	as5011->i2c_client = client;
250 	as5011->input_dev = input_dev;
251 	as5011->button_gpio = plat_data->button_gpio;
252 	as5011->axis_irq = plat_data->axis_irq;
253 
254 	input_dev->name = "Austria Microsystem as5011 joystick";
255 	input_dev->id.bustype = BUS_I2C;
256 	input_dev->dev.parent = &client->dev;
257 
258 	__set_bit(EV_KEY, input_dev->evbit);
259 	__set_bit(EV_ABS, input_dev->evbit);
260 	__set_bit(BTN_JOYSTICK, input_dev->keybit);
261 
262 	input_set_abs_params(input_dev, ABS_X,
263 		AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
264 	input_set_abs_params(as5011->input_dev, ABS_Y,
265 		AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
266 
267 	error = gpio_request(as5011->button_gpio, "AS5011 button");
268 	if (error < 0) {
269 		dev_err(&client->dev, "Failed to request button gpio\n");
270 		goto err_free_mem;
271 	}
272 
273 	irq = gpio_to_irq(as5011->button_gpio);
274 	if (irq < 0) {
275 		dev_err(&client->dev,
276 			"Failed to get irq number for button gpio\n");
277 		goto err_free_button_gpio;
278 	}
279 
280 	as5011->button_irq = irq;
281 
282 	error = request_threaded_irq(as5011->button_irq,
283 				     NULL, as5011_button_interrupt,
284 				     IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
285 				     "as5011_button", as5011);
286 	if (error < 0) {
287 		dev_err(&client->dev,
288 			"Can't allocate button irq %d\n", as5011->button_irq);
289 		goto err_free_button_gpio;
290 	}
291 
292 	error = as5011_configure_chip(as5011, plat_data);
293 	if (error)
294 		goto err_free_button_irq;
295 
296 	error = request_threaded_irq(as5011->axis_irq, NULL,
297 				     as5011_axis_interrupt,
298 				     plat_data->axis_irqflags,
299 				     "as5011_joystick", as5011);
300 	if (error) {
301 		dev_err(&client->dev,
302 			"Can't allocate axis irq %d\n", plat_data->axis_irq);
303 		goto err_free_button_irq;
304 	}
305 
306 	error = input_register_device(as5011->input_dev);
307 	if (error) {
308 		dev_err(&client->dev, "Failed to register input device\n");
309 		goto err_free_axis_irq;
310 	}
311 
312 	i2c_set_clientdata(client, as5011);
313 
314 	return 0;
315 
316 err_free_axis_irq:
317 	free_irq(as5011->axis_irq, as5011);
318 err_free_button_irq:
319 	free_irq(as5011->button_irq, as5011);
320 err_free_button_gpio:
321 	gpio_free(as5011->button_gpio);
322 err_free_mem:
323 	input_free_device(input_dev);
324 	kfree(as5011);
325 
326 	return error;
327 }
328 
as5011_remove(struct i2c_client * client)329 static int __devexit as5011_remove(struct i2c_client *client)
330 {
331 	struct as5011_device *as5011 = i2c_get_clientdata(client);
332 
333 	free_irq(as5011->axis_irq, as5011);
334 	free_irq(as5011->button_irq, as5011);
335 	gpio_free(as5011->button_gpio);
336 
337 	input_unregister_device(as5011->input_dev);
338 	kfree(as5011);
339 
340 	return 0;
341 }
342 
343 static const struct i2c_device_id as5011_id[] = {
344 	{ MODULE_DEVICE_ALIAS, 0 },
345 	{ }
346 };
347 MODULE_DEVICE_TABLE(i2c, as5011_id);
348 
349 static struct i2c_driver as5011_driver = {
350 	.driver = {
351 		.name = "as5011",
352 	},
353 	.probe		= as5011_probe,
354 	.remove		= __devexit_p(as5011_remove),
355 	.id_table	= as5011_id,
356 };
357 
358 module_i2c_driver(as5011_driver);
359