1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2010, 2011 Fabien Marteau <fabien.marteau@armadeus.com>
4 * Sponsored by ARMadeus Systems
5 *
6 * Driver for Austria Microsystems joysticks AS5011
7 *
8 * TODO:
9 * - Power on the chip when open() and power down when close()
10 * - Manage power mode
11 */
12
13 #include <linux/i2c.h>
14 #include <linux/interrupt.h>
15 #include <linux/input.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/delay.h>
18 #include <linux/input/as5011.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21
22 #define DRIVER_DESC "Driver for Austria Microsystems AS5011 joystick"
23 #define MODULE_DEVICE_ALIAS "as5011"
24
25 MODULE_AUTHOR("Fabien Marteau <fabien.marteau@armadeus.com>");
26 MODULE_DESCRIPTION(DRIVER_DESC);
27 MODULE_LICENSE("GPL");
28
29 /* registers */
30 #define AS5011_CTRL1 0x76
31 #define AS5011_CTRL2 0x75
32 #define AS5011_XP 0x43
33 #define AS5011_XN 0x44
34 #define AS5011_YP 0x53
35 #define AS5011_YN 0x54
36 #define AS5011_X_REG 0x41
37 #define AS5011_Y_REG 0x42
38 #define AS5011_X_RES_INT 0x51
39 #define AS5011_Y_RES_INT 0x52
40
41 /* CTRL1 bits */
42 #define AS5011_CTRL1_LP_PULSED 0x80
43 #define AS5011_CTRL1_LP_ACTIVE 0x40
44 #define AS5011_CTRL1_LP_CONTINUE 0x20
45 #define AS5011_CTRL1_INT_WUP_EN 0x10
46 #define AS5011_CTRL1_INT_ACT_EN 0x08
47 #define AS5011_CTRL1_EXT_CLK_EN 0x04
48 #define AS5011_CTRL1_SOFT_RST 0x02
49 #define AS5011_CTRL1_DATA_VALID 0x01
50
51 /* CTRL2 bits */
52 #define AS5011_CTRL2_EXT_SAMPLE_EN 0x08
53 #define AS5011_CTRL2_RC_BIAS_ON 0x04
54 #define AS5011_CTRL2_INV_SPINNING 0x02
55
56 #define AS5011_MAX_AXIS 80
57 #define AS5011_MIN_AXIS (-80)
58 #define AS5011_FUZZ 8
59 #define AS5011_FLAT 40
60
61 struct as5011_device {
62 struct input_dev *input_dev;
63 struct i2c_client *i2c_client;
64 struct gpio_desc *button_gpiod;
65 unsigned int button_irq;
66 unsigned int axis_irq;
67 };
68
as5011_i2c_write(struct i2c_client * client,uint8_t aregaddr,uint8_t avalue)69 static int as5011_i2c_write(struct i2c_client *client,
70 uint8_t aregaddr,
71 uint8_t avalue)
72 {
73 uint8_t data[2] = { aregaddr, avalue };
74 struct i2c_msg msg = {
75 .addr = client->addr,
76 .flags = I2C_M_IGNORE_NAK,
77 .len = 2,
78 .buf = (uint8_t *)data
79 };
80 int error;
81
82 error = i2c_transfer(client->adapter, &msg, 1);
83 return error < 0 ? error : 0;
84 }
85
as5011_i2c_read(struct i2c_client * client,uint8_t aregaddr,signed char * value)86 static int as5011_i2c_read(struct i2c_client *client,
87 uint8_t aregaddr, signed char *value)
88 {
89 uint8_t data[2] = { aregaddr };
90 struct i2c_msg msg_set[2] = {
91 {
92 .addr = client->addr,
93 .flags = I2C_M_REV_DIR_ADDR,
94 .len = 1,
95 .buf = (uint8_t *)data
96 },
97 {
98 .addr = client->addr,
99 .flags = I2C_M_RD | I2C_M_NOSTART,
100 .len = 1,
101 .buf = (uint8_t *)data
102 }
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 = gpiod_get_value_cansleep(as5011->button_gpiod);
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 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)215 static int as5011_probe(struct i2c_client *client)
216 {
217 const struct as5011_platform_data *plat_data;
218 struct as5011_device *as5011;
219 struct input_dev *input_dev;
220 int irq;
221 int error;
222
223 plat_data = dev_get_platdata(&client->dev);
224 if (!plat_data)
225 return -EINVAL;
226
227 if (!plat_data->axis_irq) {
228 dev_err(&client->dev, "No axis IRQ?\n");
229 return -EINVAL;
230 }
231
232 if (!i2c_check_functionality(client->adapter,
233 I2C_FUNC_NOSTART |
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(*as5011), 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->axis_irq = plat_data->axis_irq;
252
253 input_dev->name = "Austria Microsystem as5011 joystick";
254 input_dev->id.bustype = BUS_I2C;
255 input_dev->dev.parent = &client->dev;
256
257 input_set_capability(input_dev, EV_KEY, BTN_JOYSTICK);
258
259 input_set_abs_params(input_dev, ABS_X,
260 AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
261 input_set_abs_params(as5011->input_dev, ABS_Y,
262 AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
263
264 as5011->button_gpiod = devm_gpiod_get(&client->dev, NULL, GPIOD_IN);
265 if (IS_ERR(as5011->button_gpiod)) {
266 error = PTR_ERR(as5011->button_gpiod);
267 dev_err(&client->dev, "Failed to request button GPIO\n");
268 goto err_free_mem;
269 }
270 gpiod_set_consumer_name(as5011->button_gpiod, "AS5011 button");
271
272 irq = gpiod_to_irq(as5011->button_gpiod);
273 if (irq < 0) {
274 dev_err(&client->dev,
275 "Failed to get irq number for button gpio\n");
276 error = irq;
277 goto err_free_mem;
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 |
285 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
286 "as5011_button", as5011);
287 if (error < 0) {
288 dev_err(&client->dev,
289 "Can't allocate button irq %d\n", as5011->button_irq);
290 goto err_free_mem;
291 }
292
293 error = as5011_configure_chip(as5011, plat_data);
294 if (error)
295 goto err_free_button_irq;
296
297 error = request_threaded_irq(as5011->axis_irq, NULL,
298 as5011_axis_interrupt,
299 plat_data->axis_irqflags | IRQF_ONESHOT,
300 "as5011_joystick", as5011);
301 if (error) {
302 dev_err(&client->dev,
303 "Can't allocate axis irq %d\n", plat_data->axis_irq);
304 goto err_free_button_irq;
305 }
306
307 error = input_register_device(as5011->input_dev);
308 if (error) {
309 dev_err(&client->dev, "Failed to register input device\n");
310 goto err_free_axis_irq;
311 }
312
313 i2c_set_clientdata(client, as5011);
314
315 return 0;
316
317 err_free_axis_irq:
318 free_irq(as5011->axis_irq, as5011);
319 err_free_button_irq:
320 free_irq(as5011->button_irq, as5011);
321 err_free_mem:
322 input_free_device(input_dev);
323 kfree(as5011);
324
325 return error;
326 }
327
as5011_remove(struct i2c_client * client)328 static void as5011_remove(struct i2c_client *client)
329 {
330 struct as5011_device *as5011 = i2c_get_clientdata(client);
331
332 free_irq(as5011->axis_irq, as5011);
333 free_irq(as5011->button_irq, as5011);
334
335 input_unregister_device(as5011->input_dev);
336 kfree(as5011);
337 }
338
339 static const struct i2c_device_id as5011_id[] = {
340 { MODULE_DEVICE_ALIAS },
341 { }
342 };
343 MODULE_DEVICE_TABLE(i2c, as5011_id);
344
345 static struct i2c_driver as5011_driver = {
346 .driver = {
347 .name = "as5011",
348 },
349 .probe = as5011_probe,
350 .remove = as5011_remove,
351 .id_table = as5011_id,
352 };
353
354 module_i2c_driver(as5011_driver);
355