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.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
25MODULE_AUTHOR("Fabien Marteau <fabien.marteau@armadeus.com>");
26MODULE_DESCRIPTION(DRIVER_DESC);
27MODULE_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
61struct as5011_device {
62	struct input_dev *input_dev;
63	struct i2c_client *i2c_client;
64	unsigned int button_gpio;
65	unsigned int button_irq;
66	unsigned int axis_irq;
67};
68
69static 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
86static 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
114static 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
125static 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
143out:
144	return IRQ_HANDLED;
145}
146
147static 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
215static 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(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	input_set_capability(input_dev, EV_KEY, BTN_JOYSTICK);
259
260	input_set_abs_params(input_dev, ABS_X,
261		AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
262	input_set_abs_params(as5011->input_dev, ABS_Y,
263		AS5011_MIN_AXIS, AS5011_MAX_AXIS, AS5011_FUZZ, AS5011_FLAT);
264
265	error = gpio_request(as5011->button_gpio, "AS5011 button");
266	if (error < 0) {
267		dev_err(&client->dev, "Failed to request button gpio\n");
268		goto err_free_mem;
269	}
270
271	irq = gpio_to_irq(as5011->button_gpio);
272	if (irq < 0) {
273		dev_err(&client->dev,
274			"Failed to get irq number for button gpio\n");
275		error = irq;
276		goto err_free_button_gpio;
277	}
278
279	as5011->button_irq = irq;
280
281	error = request_threaded_irq(as5011->button_irq,
282				     NULL, as5011_button_interrupt,
283				     IRQF_TRIGGER_RISING |
284					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
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 | IRQF_ONESHOT,
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
316err_free_axis_irq:
317	free_irq(as5011->axis_irq, as5011);
318err_free_button_irq:
319	free_irq(as5011->button_irq, as5011);
320err_free_button_gpio:
321	gpio_free(as5011->button_gpio);
322err_free_mem:
323	input_free_device(input_dev);
324	kfree(as5011);
325
326	return error;
327}
328
329static void 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
341static const struct i2c_device_id as5011_id[] = {
342	{ MODULE_DEVICE_ALIAS, 0 },
343	{ }
344};
345MODULE_DEVICE_TABLE(i2c, as5011_id);
346
347static struct i2c_driver as5011_driver = {
348	.driver = {
349		.name = "as5011",
350	},
351	.probe		= as5011_probe,
352	.remove		= as5011_remove,
353	.id_table	= as5011_id,
354};
355
356module_i2c_driver(as5011_driver);
357