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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Intel La Jolla Cove Adapter USB-I2C driver4 *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 60u30#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(ljca_i2c->ljca, LJCA_I2C_INIT, (u8 *)w_packet,74 struct_size(w_packet, data, 1), NULL, 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(ljca_i2c->ljca, LJCA_I2C_START, (u8 *)w_packet,94 struct_size(w_packet, data, 1), (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(ljca_i2c->ljca, LJCA_I2C_STOP, (u8 *)w_packet,124 struct_size(w_packet, data, 1), (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(ljca_i2c->ljca, LJCA_I2C_READ, (u8 *)w_packet,154 struct_size(w_packet, data, 1), (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, 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(ljca_i2c->ljca, LJCA_I2C_WRITE, (u8 *)w_packet,200 struct_size(w_packet, data, len), (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, 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(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, cur_msg->addr,245 cur_msg->buf, cur_msg->len);246 else247 ret = ljca_i2c_write(ljca_i2c, cur_msg->addr,248 cur_msg->buf, 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(&auxdev->dev, 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(&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(ljca_i2c->adap.name, sizeof(ljca_i2c->adap.name), "%s-%s-%d",294 dev_name(&auxdev->dev), dev_name(auxdev->dev.parent),295 ljca_i2c->i2c_info->id);296 297 device_set_node(&ljca_i2c->adap.dev, dev_fwnode(&auxdev->dev));298 299 i2c_set_adapdata(&ljca_i2c->adap, ljca_i2c);300 auxiliary_set_drvdata(auxdev, ljca_i2c);301 302 ret = ljca_i2c_init(ljca_i2c, ljca_i2c->i2c_info->id);303 if (ret)304 return dev_err_probe(&auxdev->dev, -EIO,305 "i2c init failed id: %d\n",306 ljca_i2c->i2c_info->id);307 308 ret = devm_i2c_add_adapter(&auxdev->dev, &ljca_i2c->adap);309 if (ret)310 return ret;311 312 if (has_acpi_companion(&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(&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