xref: /kernel/linux/linux-6.6/drivers/hwmon/atxp1.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * atxp1.c - kernel module for setting CPU VID and general purpose
4 *	     I/Os using the Attansic ATXP1 chip.
5 *
6 * The ATXP1 can reside on I2C addresses 0x37 or 0x4e. The chip is
7 * not auto-detected by the driver and must be instantiated explicitly.
8 * See Documentation/i2c/instantiating-devices.rst for more information.
9 */
10
11#include <linux/kernel.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/jiffies.h>
15#include <linux/i2c.h>
16#include <linux/hwmon.h>
17#include <linux/hwmon-vid.h>
18#include <linux/err.h>
19#include <linux/kstrtox.h>
20#include <linux/mutex.h>
21#include <linux/sysfs.h>
22#include <linux/slab.h>
23
24MODULE_LICENSE("GPL");
25MODULE_DESCRIPTION("System voltages control via Attansic ATXP1");
26MODULE_VERSION("0.6.3");
27MODULE_AUTHOR("Sebastian Witt <se.witt@gmx.net>");
28
29#define ATXP1_VID	0x00
30#define ATXP1_CVID	0x01
31#define ATXP1_GPIO1	0x06
32#define ATXP1_GPIO2	0x0a
33#define ATXP1_VIDENA	0x20
34#define ATXP1_VIDMASK	0x1f
35#define ATXP1_GPIO1MASK	0x0f
36
37struct atxp1_data {
38	struct i2c_client *client;
39	struct mutex update_lock;
40	unsigned long last_updated;
41	bool valid;
42	struct {
43		u8 vid;		/* VID output register */
44		u8 cpu_vid; /* VID input from CPU */
45		u8 gpio1;   /* General purpose I/O register 1 */
46		u8 gpio2;   /* General purpose I/O register 2 */
47	} reg;
48	u8 vrm;			/* Detected CPU VRM */
49};
50
51static struct atxp1_data *atxp1_update_device(struct device *dev)
52{
53	struct atxp1_data *data = dev_get_drvdata(dev);
54	struct i2c_client *client = data->client;
55
56	mutex_lock(&data->update_lock);
57
58	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
59
60		/* Update local register data */
61		data->reg.vid = i2c_smbus_read_byte_data(client, ATXP1_VID);
62		data->reg.cpu_vid = i2c_smbus_read_byte_data(client,
63							     ATXP1_CVID);
64		data->reg.gpio1 = i2c_smbus_read_byte_data(client, ATXP1_GPIO1);
65		data->reg.gpio2 = i2c_smbus_read_byte_data(client, ATXP1_GPIO2);
66
67		data->valid = true;
68	}
69
70	mutex_unlock(&data->update_lock);
71
72	return data;
73}
74
75/* sys file functions for cpu0_vid */
76static ssize_t cpu0_vid_show(struct device *dev,
77			     struct device_attribute *attr, char *buf)
78{
79	int size;
80	struct atxp1_data *data;
81
82	data = atxp1_update_device(dev);
83
84	size = sprintf(buf, "%d\n", vid_from_reg(data->reg.vid & ATXP1_VIDMASK,
85						 data->vrm));
86
87	return size;
88}
89
90static ssize_t cpu0_vid_store(struct device *dev,
91			      struct device_attribute *attr, const char *buf,
92			      size_t count)
93{
94	struct atxp1_data *data = atxp1_update_device(dev);
95	struct i2c_client *client = data->client;
96	int vid, cvid;
97	unsigned long vcore;
98	int err;
99
100	err = kstrtoul(buf, 10, &vcore);
101	if (err)
102		return err;
103
104	vcore /= 25;
105	vcore *= 25;
106
107	/* Calculate VID */
108	vid = vid_to_reg(vcore, data->vrm);
109	if (vid < 0) {
110		dev_err(dev, "VID calculation failed.\n");
111		return vid;
112	}
113
114	/*
115	 * If output enabled, use control register value.
116	 * Otherwise original CPU VID
117	 */
118	if (data->reg.vid & ATXP1_VIDENA)
119		cvid = data->reg.vid & ATXP1_VIDMASK;
120	else
121		cvid = data->reg.cpu_vid;
122
123	/* Nothing changed, aborting */
124	if (vid == cvid)
125		return count;
126
127	dev_dbg(dev, "Setting VCore to %d mV (0x%02x)\n", (int)vcore, vid);
128
129	/* Write every 25 mV step to increase stability */
130	if (cvid > vid) {
131		for (; cvid >= vid; cvid--)
132			i2c_smbus_write_byte_data(client,
133						ATXP1_VID, cvid | ATXP1_VIDENA);
134	} else {
135		for (; cvid <= vid; cvid++)
136			i2c_smbus_write_byte_data(client,
137						ATXP1_VID, cvid | ATXP1_VIDENA);
138	}
139
140	data->valid = false;
141
142	return count;
143}
144
145/*
146 * CPU core reference voltage
147 * unit: millivolt
148 */
149static DEVICE_ATTR_RW(cpu0_vid);
150
151/* sys file functions for GPIO1 */
152static ssize_t gpio1_show(struct device *dev, struct device_attribute *attr,
153			  char *buf)
154{
155	int size;
156	struct atxp1_data *data;
157
158	data = atxp1_update_device(dev);
159
160	size = sprintf(buf, "0x%02x\n", data->reg.gpio1 & ATXP1_GPIO1MASK);
161
162	return size;
163}
164
165static ssize_t gpio1_store(struct device *dev, struct device_attribute *attr,
166			   const char *buf, size_t count)
167{
168	struct atxp1_data *data = atxp1_update_device(dev);
169	struct i2c_client *client = data->client;
170	unsigned long value;
171	int err;
172
173	err = kstrtoul(buf, 16, &value);
174	if (err)
175		return err;
176
177	value &= ATXP1_GPIO1MASK;
178
179	if (value != (data->reg.gpio1 & ATXP1_GPIO1MASK)) {
180		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
181
182		i2c_smbus_write_byte_data(client, ATXP1_GPIO1, value);
183
184		data->valid = false;
185	}
186
187	return count;
188}
189
190/*
191 * GPIO1 data register
192 * unit: Four bit as hex (e.g. 0x0f)
193 */
194static DEVICE_ATTR_RW(gpio1);
195
196/* sys file functions for GPIO2 */
197static ssize_t gpio2_show(struct device *dev, struct device_attribute *attr,
198			  char *buf)
199{
200	int size;
201	struct atxp1_data *data;
202
203	data = atxp1_update_device(dev);
204
205	size = sprintf(buf, "0x%02x\n", data->reg.gpio2);
206
207	return size;
208}
209
210static ssize_t gpio2_store(struct device *dev, struct device_attribute *attr,
211			   const char *buf, size_t count)
212{
213	struct atxp1_data *data = atxp1_update_device(dev);
214	struct i2c_client *client = data->client;
215	unsigned long value;
216	int err;
217
218	err = kstrtoul(buf, 16, &value);
219	if (err)
220		return err;
221	value &= 0xff;
222
223	if (value != data->reg.gpio2) {
224		dev_info(dev, "Writing 0x%x to GPIO1.\n", (unsigned int)value);
225
226		i2c_smbus_write_byte_data(client, ATXP1_GPIO2, value);
227
228		data->valid = false;
229	}
230
231	return count;
232}
233
234/*
235 * GPIO2 data register
236 * unit: Eight bit as hex (e.g. 0xff)
237 */
238static DEVICE_ATTR_RW(gpio2);
239
240static struct attribute *atxp1_attrs[] = {
241	&dev_attr_gpio1.attr,
242	&dev_attr_gpio2.attr,
243	&dev_attr_cpu0_vid.attr,
244	NULL
245};
246ATTRIBUTE_GROUPS(atxp1);
247
248static int atxp1_probe(struct i2c_client *client)
249{
250	struct device *dev = &client->dev;
251	struct atxp1_data *data;
252	struct device *hwmon_dev;
253
254	data = devm_kzalloc(dev, sizeof(struct atxp1_data), GFP_KERNEL);
255	if (!data)
256		return -ENOMEM;
257
258	/* Get VRM */
259	data->vrm = vid_which_vrm();
260	if (data->vrm != 90 && data->vrm != 91) {
261		dev_err(dev, "atxp1: Not supporting VRM %d.%d\n",
262			data->vrm / 10, data->vrm % 10);
263		return -ENODEV;
264	}
265
266	data->client = client;
267	mutex_init(&data->update_lock);
268
269	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
270							   data,
271							   atxp1_groups);
272	if (IS_ERR(hwmon_dev))
273		return PTR_ERR(hwmon_dev);
274
275	dev_info(dev, "Using VRM: %d.%d\n", data->vrm / 10, data->vrm % 10);
276
277	return 0;
278};
279
280static const struct i2c_device_id atxp1_id[] = {
281	{ "atxp1", 0 },
282	{ }
283};
284MODULE_DEVICE_TABLE(i2c, atxp1_id);
285
286static struct i2c_driver atxp1_driver = {
287	.class		= I2C_CLASS_HWMON,
288	.driver = {
289		.name	= "atxp1",
290	},
291	.probe		= atxp1_probe,
292	.id_table	= atxp1_id,
293};
294
295module_i2c_driver(atxp1_driver);
296