1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Intel La Jolla Cove Adapter USB-I2C driver
4 *
5 * Copyright (c) 2023, Intel Corporation.
6 */
7
8#include <linux/acpi.h>
9#include <linux/auxiliary_bus.h>
10#include <linux/bitfield.h>
11#include <linux/bits.h>
12#include <linux/dev_printk.h>
13#include <linux/i2c.h>
14#include <linux/module.h>
15#include <linux/usb/ljca.h>
16
17/* I2C init flags */
18#define LJCA_I2C_INIT_FLAG_MODE BIT(0)
19#define LJCA_I2C_INIT_FLAG_MODE_POLLING FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 0)
20#define LJCA_I2C_INIT_FLAG_MODE_INTERRUPT FIELD_PREP(LJCA_I2C_INIT_FLAG_MODE, 1)
21
22#define LJCA_I2C_INIT_FLAG_ADDR_16BIT BIT(0)
23
24#define LJCA_I2C_INIT_FLAG_FREQ GENMASK(2, 1)
25#define LJCA_I2C_INIT_FLAG_FREQ_100K FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 0)
26#define LJCA_I2C_INIT_FLAG_FREQ_400K FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 1)
27#define LJCA_I2C_INIT_FLAG_FREQ_1M FIELD_PREP(LJCA_I2C_INIT_FLAG_FREQ, 2)
28
29#define LJCA_I2C_BUF_SIZE 60u
30#define LJCA_I2C_MAX_XFER_SIZE (LJCA_I2C_BUF_SIZE - sizeof(struct ljca_i2c_rw_packet))
31
32/* I2C commands */
33enum ljca_i2c_cmd {
34 LJCA_I2C_INIT = 1,
35 LJCA_I2C_XFER,
36 LJCA_I2C_START,
37 LJCA_I2C_STOP,
38 LJCA_I2C_READ,
39 LJCA_I2C_WRITE,
40};
41
42enum ljca_xfer_type {
43 LJCA_I2C_WRITE_XFER_TYPE,
44 LJCA_I2C_READ_XFER_TYPE,
45};
46
47/* I2C raw commands: Init/Start/Read/Write/Stop */
48struct ljca_i2c_rw_packet {
49 u8 id;
50 __le16 len;
51 u8 data[] __counted_by(len);
52} __packed;
53
54struct ljca_i2c_dev {
55 struct ljca_client *ljca;
56 struct ljca_i2c_info *i2c_info;
57 struct i2c_adapter adap;
58
59 u8 obuf[LJCA_I2C_BUF_SIZE];
60 u8 ibuf[LJCA_I2C_BUF_SIZE];
61};
62
63static int ljca_i2c_init(struct ljca_i2c_dev *ljca_i2c, u8 id)
64{
65 struct ljca_i2c_rw_packet *w_packet =
66 (struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
67 int ret;
68
69 w_packet->id = id;
70 w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
71 w_packet->data[0] = LJCA_I2C_INIT_FLAG_FREQ_400K;
72
73 ret = ljca_transfer(client: ljca_i2c->ljca, cmd: LJCA_I2C_INIT, obuf: (u8 *)w_packet,
74 struct_size(w_packet, data, 1), NULL, ibuf_len: 0);
75
76 return ret < 0 ? ret : 0;
77}
78
79static int ljca_i2c_start(struct ljca_i2c_dev *ljca_i2c, u8 target_addr,
80 enum ljca_xfer_type type)
81{
82 struct ljca_i2c_rw_packet *w_packet =
83 (struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
84 struct ljca_i2c_rw_packet *r_packet =
85 (struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
86 s16 rp_len;
87 int ret;
88
89 w_packet->id = ljca_i2c->i2c_info->id;
90 w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
91 w_packet->data[0] = (target_addr << 1) | type;
92
93 ret = ljca_transfer(client: ljca_i2c->ljca, cmd: LJCA_I2C_START, obuf: (u8 *)w_packet,
94 struct_size(w_packet, data, 1), ibuf: (u8 *)r_packet,
95 LJCA_I2C_BUF_SIZE);
96 if (ret < 0 || ret < sizeof(*r_packet))
97 return ret < 0 ? ret : -EIO;
98
99 rp_len = le16_to_cpu(r_packet->len);
100 if (rp_len < 0 || r_packet->id != w_packet->id) {
101 dev_dbg(&ljca_i2c->adap.dev,
102 "i2c start failed len: %d id: %d %d\n",
103 rp_len, r_packet->id, w_packet->id);
104 return -EIO;
105 }
106
107 return 0;
108}
109
110static void ljca_i2c_stop(struct ljca_i2c_dev *ljca_i2c)
111{
112 struct ljca_i2c_rw_packet *w_packet =
113 (struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
114 struct ljca_i2c_rw_packet *r_packet =
115 (struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
116 s16 rp_len;
117 int ret;
118
119 w_packet->id = ljca_i2c->i2c_info->id;
120 w_packet->len = cpu_to_le16(sizeof(*w_packet->data));
121 w_packet->data[0] = 0;
122
123 ret = ljca_transfer(client: ljca_i2c->ljca, cmd: LJCA_I2C_STOP, obuf: (u8 *)w_packet,
124 struct_size(w_packet, data, 1), ibuf: (u8 *)r_packet,
125 LJCA_I2C_BUF_SIZE);
126 if (ret < 0 || ret < sizeof(*r_packet)) {
127 dev_dbg(&ljca_i2c->adap.dev,
128 "i2c stop failed ret: %d id: %d\n",
129 ret, w_packet->id);
130 return;
131 }
132
133 rp_len = le16_to_cpu(r_packet->len);
134 if (rp_len < 0 || r_packet->id != w_packet->id)
135 dev_dbg(&ljca_i2c->adap.dev,
136 "i2c stop failed len: %d id: %d %d\n",
137 rp_len, r_packet->id, w_packet->id);
138}
139
140static int ljca_i2c_pure_read(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
141{
142 struct ljca_i2c_rw_packet *w_packet =
143 (struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
144 struct ljca_i2c_rw_packet *r_packet =
145 (struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
146 s16 rp_len;
147 int ret;
148
149 w_packet->id = ljca_i2c->i2c_info->id;
150 w_packet->len = cpu_to_le16(len);
151 w_packet->data[0] = 0;
152
153 ret = ljca_transfer(client: ljca_i2c->ljca, cmd: LJCA_I2C_READ, obuf: (u8 *)w_packet,
154 struct_size(w_packet, data, 1), ibuf: (u8 *)r_packet,
155 LJCA_I2C_BUF_SIZE);
156 if (ret < 0 || ret < sizeof(*r_packet))
157 return ret < 0 ? ret : -EIO;
158
159 rp_len = le16_to_cpu(r_packet->len);
160 if (rp_len != len || r_packet->id != w_packet->id) {
161 dev_dbg(&ljca_i2c->adap.dev,
162 "i2c raw read failed len: %d id: %d %d\n",
163 rp_len, r_packet->id, w_packet->id);
164 return -EIO;
165 }
166
167 memcpy(data, r_packet->data, len);
168
169 return 0;
170}
171
172static int ljca_i2c_read(struct ljca_i2c_dev *ljca_i2c, u8 target_addr, u8 *data,
173 u8 len)
174{
175 int ret;
176
177 ret = ljca_i2c_start(ljca_i2c, target_addr, type: LJCA_I2C_READ_XFER_TYPE);
178 if (!ret)
179 ret = ljca_i2c_pure_read(ljca_i2c, data, len);
180
181 ljca_i2c_stop(ljca_i2c);
182
183 return ret;
184}
185
186static int ljca_i2c_pure_write(struct ljca_i2c_dev *ljca_i2c, u8 *data, u8 len)
187{
188 struct ljca_i2c_rw_packet *w_packet =
189 (struct ljca_i2c_rw_packet *)ljca_i2c->obuf;
190 struct ljca_i2c_rw_packet *r_packet =
191 (struct ljca_i2c_rw_packet *)ljca_i2c->ibuf;
192 s16 rplen;
193 int ret;
194
195 w_packet->id = ljca_i2c->i2c_info->id;
196 w_packet->len = cpu_to_le16(len);
197 memcpy(w_packet->data, data, len);
198
199 ret = ljca_transfer(client: ljca_i2c->ljca, cmd: LJCA_I2C_WRITE, obuf: (u8 *)w_packet,
200 struct_size(w_packet, data, len), ibuf: (u8 *)r_packet,
201 LJCA_I2C_BUF_SIZE);
202 if (ret < 0 || ret < sizeof(*r_packet))
203 return ret < 0 ? ret : -EIO;
204
205 rplen = le16_to_cpu(r_packet->len);
206 if (rplen != len || r_packet->id != w_packet->id) {
207 dev_dbg(&ljca_i2c->adap.dev,
208 "i2c write failed len: %d id: %d/%d\n",
209 rplen, r_packet->id, w_packet->id);
210 return -EIO;
211 }
212
213 return 0;
214}
215
216static int ljca_i2c_write(struct ljca_i2c_dev *ljca_i2c, u8 target_addr,
217 u8 *data, u8 len)
218{
219 int ret;
220
221 ret = ljca_i2c_start(ljca_i2c, target_addr, type: LJCA_I2C_WRITE_XFER_TYPE);
222 if (!ret)
223 ret = ljca_i2c_pure_write(ljca_i2c, data, len);
224
225 ljca_i2c_stop(ljca_i2c);
226
227 return ret;
228}
229
230static int ljca_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msg,
231 int num)
232{
233 struct ljca_i2c_dev *ljca_i2c;
234 struct i2c_msg *cur_msg;
235 int i, ret;
236
237 ljca_i2c = i2c_get_adapdata(adap: adapter);
238 if (!ljca_i2c)
239 return -EINVAL;
240
241 for (i = 0; i < num; i++) {
242 cur_msg = &msg[i];
243 if (cur_msg->flags & I2C_M_RD)
244 ret = ljca_i2c_read(ljca_i2c, target_addr: cur_msg->addr,
245 data: cur_msg->buf, len: cur_msg->len);
246 else
247 ret = ljca_i2c_write(ljca_i2c, target_addr: cur_msg->addr,
248 data: cur_msg->buf, len: cur_msg->len);
249
250 if (ret)
251 return ret;
252 }
253
254 return num;
255}
256
257static u32 ljca_i2c_func(struct i2c_adapter *adap)
258{
259 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
260}
261
262static const struct i2c_adapter_quirks ljca_i2c_quirks = {
263 .flags = I2C_AQ_NO_ZERO_LEN,
264 .max_read_len = LJCA_I2C_MAX_XFER_SIZE,
265 .max_write_len = LJCA_I2C_MAX_XFER_SIZE,
266};
267
268static const struct i2c_algorithm ljca_i2c_algo = {
269 .xfer = ljca_i2c_xfer,
270 .functionality = ljca_i2c_func,
271};
272
273static int ljca_i2c_probe(struct auxiliary_device *auxdev,
274 const struct auxiliary_device_id *aux_dev_id)
275{
276 struct ljca_client *ljca = auxiliary_dev_to_ljca_client(auxdev);
277 struct ljca_i2c_dev *ljca_i2c;
278 int ret;
279
280 ljca_i2c = devm_kzalloc(dev: &auxdev->dev, size: sizeof(*ljca_i2c), GFP_KERNEL);
281 if (!ljca_i2c)
282 return -ENOMEM;
283
284 ljca_i2c->ljca = ljca;
285 ljca_i2c->i2c_info = dev_get_platdata(dev: &auxdev->dev);
286
287 ljca_i2c->adap.owner = THIS_MODULE;
288 ljca_i2c->adap.class = I2C_CLASS_HWMON;
289 ljca_i2c->adap.algo = &ljca_i2c_algo;
290 ljca_i2c->adap.quirks = &ljca_i2c_quirks;
291 ljca_i2c->adap.dev.parent = &auxdev->dev;
292
293 snprintf(buf: ljca_i2c->adap.name, size: sizeof(ljca_i2c->adap.name), fmt: "%s-%s-%d",
294 dev_name(dev: &auxdev->dev), dev_name(dev: auxdev->dev.parent),
295 ljca_i2c->i2c_info->id);
296
297 device_set_node(dev: &ljca_i2c->adap.dev, dev_fwnode(&auxdev->dev));
298
299 i2c_set_adapdata(adap: &ljca_i2c->adap, data: ljca_i2c);
300 auxiliary_set_drvdata(auxdev, data: ljca_i2c);
301
302 ret = ljca_i2c_init(ljca_i2c, id: ljca_i2c->i2c_info->id);
303 if (ret)
304 return dev_err_probe(dev: &auxdev->dev, err: -EIO,
305 fmt: "i2c init failed id: %d\n",
306 ljca_i2c->i2c_info->id);
307
308 ret = devm_i2c_add_adapter(dev: &auxdev->dev, adapter: &ljca_i2c->adap);
309 if (ret)
310 return ret;
311
312 if (has_acpi_companion(dev: &ljca_i2c->adap.dev))
313 acpi_dev_clear_dependencies(ACPI_COMPANION(&ljca_i2c->adap.dev));
314
315 return 0;
316}
317
318static void ljca_i2c_remove(struct auxiliary_device *auxdev)
319{
320 struct ljca_i2c_dev *ljca_i2c = auxiliary_get_drvdata(auxdev);
321
322 i2c_del_adapter(adap: &ljca_i2c->adap);
323}
324
325static const struct auxiliary_device_id ljca_i2c_id_table[] = {
326 { "usb_ljca.ljca-i2c", 0 },
327 { /* sentinel */ }
328};
329MODULE_DEVICE_TABLE(auxiliary, ljca_i2c_id_table);
330
331static struct auxiliary_driver ljca_i2c_driver = {
332 .probe = ljca_i2c_probe,
333 .remove = ljca_i2c_remove,
334 .id_table = ljca_i2c_id_table,
335};
336module_auxiliary_driver(ljca_i2c_driver);
337
338MODULE_AUTHOR("Wentong Wu <wentong.wu@intel.com>");
339MODULE_AUTHOR("Zhifeng Wang <zhifeng.wang@intel.com>");
340MODULE_AUTHOR("Lixu Zhang <lixu.zhang@intel.com>");
341MODULE_DESCRIPTION("Intel La Jolla Cove Adapter USB-I2C driver");
342MODULE_LICENSE("GPL");
343MODULE_IMPORT_NS("LJCA");
344

source code of linux/drivers/i2c/busses/i2c-ljca.c