Thomas Gleixner | 9952f69 | 2019-05-28 10:10:04 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 2 | /* |
| 3 | * drivers/i2c/busses/i2c-tegra-bpmp.c |
| 4 | * |
| 5 | * Copyright (c) 2016 NVIDIA Corporation. All rights reserved. |
| 6 | * |
| 7 | * Author: Shardar Shariff Md <smohammed@nvidia.com> |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #include <linux/err.h> |
| 11 | #include <linux/i2c.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/of_device.h> |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/pm_runtime.h> |
| 18 | |
| 19 | #include <soc/tegra/bpmp-abi.h> |
| 20 | #include <soc/tegra/bpmp.h> |
| 21 | |
| 22 | /* |
| 23 | * Serialized I2C message header size is 6 bytes and includes address, flags |
| 24 | * and length |
| 25 | */ |
| 26 | #define SERIALI2C_HDR_SIZE 6 |
| 27 | |
| 28 | struct tegra_bpmp_i2c { |
| 29 | struct i2c_adapter adapter; |
| 30 | struct device *dev; |
| 31 | |
| 32 | struct tegra_bpmp *bpmp; |
| 33 | unsigned int bus; |
| 34 | }; |
| 35 | |
| 36 | /* |
| 37 | * Linux flags are translated to BPMP defined I2C flags that are used in BPMP |
| 38 | * firmware I2C driver to avoid any issues in future if Linux I2C flags are |
| 39 | * changed. |
| 40 | */ |
| 41 | static int tegra_bpmp_xlate_flags(u16 flags, u16 *out) |
| 42 | { |
| 43 | if (flags & I2C_M_TEN) { |
| 44 | *out |= SERIALI2C_TEN; |
| 45 | flags &= ~I2C_M_TEN; |
| 46 | } |
| 47 | |
| 48 | if (flags & I2C_M_RD) { |
| 49 | *out |= SERIALI2C_RD; |
| 50 | flags &= ~I2C_M_RD; |
| 51 | } |
| 52 | |
| 53 | if (flags & I2C_M_STOP) { |
| 54 | *out |= SERIALI2C_STOP; |
| 55 | flags &= ~I2C_M_STOP; |
| 56 | } |
| 57 | |
| 58 | if (flags & I2C_M_NOSTART) { |
| 59 | *out |= SERIALI2C_NOSTART; |
| 60 | flags &= ~I2C_M_NOSTART; |
| 61 | } |
| 62 | |
| 63 | if (flags & I2C_M_REV_DIR_ADDR) { |
| 64 | *out |= SERIALI2C_REV_DIR_ADDR; |
| 65 | flags &= ~I2C_M_REV_DIR_ADDR; |
| 66 | } |
| 67 | |
| 68 | if (flags & I2C_M_IGNORE_NAK) { |
| 69 | *out |= SERIALI2C_IGNORE_NAK; |
| 70 | flags &= ~I2C_M_IGNORE_NAK; |
| 71 | } |
| 72 | |
| 73 | if (flags & I2C_M_NO_RD_ACK) { |
| 74 | *out |= SERIALI2C_NO_RD_ACK; |
| 75 | flags &= ~I2C_M_NO_RD_ACK; |
| 76 | } |
| 77 | |
| 78 | if (flags & I2C_M_RECV_LEN) { |
| 79 | *out |= SERIALI2C_RECV_LEN; |
| 80 | flags &= ~I2C_M_RECV_LEN; |
| 81 | } |
| 82 | |
| 83 | return (flags != 0) ? -EINVAL : 0; |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * The serialized I2C format is simply the following: |
| 88 | * [addr little-endian][flags little-endian][len little-endian][data if write] |
| 89 | * [addr little-endian][flags little-endian][len little-endian][data if write] |
| 90 | * ... |
| 91 | * |
| 92 | * The flags are translated from Linux kernel representation to seriali2c |
| 93 | * representation. Any undefined flag being set causes an error. |
| 94 | * |
| 95 | * The data is there only for writes. Reads have the data transferred in the |
| 96 | * other direction, and thus data is not present. |
| 97 | * |
| 98 | * See deserialize_i2c documentation for the data format in the other direction. |
| 99 | */ |
| 100 | static int tegra_bpmp_serialize_i2c_msg(struct tegra_bpmp_i2c *i2c, |
| 101 | struct mrq_i2c_request *request, |
| 102 | struct i2c_msg *msgs, |
| 103 | unsigned int num) |
| 104 | { |
| 105 | char *buf = request->xfer.data_buf; |
| 106 | unsigned int i, j, pos = 0; |
| 107 | int err; |
| 108 | |
| 109 | for (i = 0; i < num; i++) { |
| 110 | struct i2c_msg *msg = &msgs[i]; |
| 111 | u16 flags = 0; |
| 112 | |
| 113 | err = tegra_bpmp_xlate_flags(msg->flags, &flags); |
| 114 | if (err < 0) |
| 115 | return err; |
| 116 | |
| 117 | buf[pos++] = msg->addr & 0xff; |
| 118 | buf[pos++] = (msg->addr & 0xff00) >> 8; |
| 119 | buf[pos++] = flags & 0xff; |
| 120 | buf[pos++] = (flags & 0xff00) >> 8; |
| 121 | buf[pos++] = msg->len & 0xff; |
| 122 | buf[pos++] = (msg->len & 0xff00) >> 8; |
| 123 | |
| 124 | if ((flags & SERIALI2C_RD) == 0) { |
| 125 | for (j = 0; j < msg->len; j++) |
| 126 | buf[pos++] = msg->buf[j]; |
| 127 | } |
| 128 | } |
| 129 | |
| 130 | request->xfer.data_size = pos; |
| 131 | |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * The data in the BPMP -> CPU direction is composed of sequential blocks for |
| 137 | * those messages that have I2C_M_RD. So, for example, if you have: |
| 138 | * |
| 139 | * - !I2C_M_RD, len == 5, data == a0 01 02 03 04 |
| 140 | * - !I2C_M_RD, len == 1, data == a0 |
| 141 | * - I2C_M_RD, len == 2, data == [uninitialized buffer 1] |
| 142 | * - !I2C_M_RD, len == 1, data == a2 |
| 143 | * - I2C_M_RD, len == 2, data == [uninitialized buffer 2] |
| 144 | * |
| 145 | * ...then the data in the BPMP -> CPU direction would be 4 bytes total, and |
| 146 | * would contain 2 bytes that will go to uninitialized buffer 1, and 2 bytes |
| 147 | * that will go to uninitialized buffer 2. |
| 148 | */ |
| 149 | static int tegra_bpmp_i2c_deserialize(struct tegra_bpmp_i2c *i2c, |
| 150 | struct mrq_i2c_response *response, |
| 151 | struct i2c_msg *msgs, |
| 152 | unsigned int num) |
| 153 | { |
| 154 | size_t size = response->xfer.data_size, len = 0, pos = 0; |
| 155 | char *buf = response->xfer.data_buf; |
| 156 | unsigned int i; |
| 157 | |
| 158 | for (i = 0; i < num; i++) |
| 159 | if (msgs[i].flags & I2C_M_RD) |
| 160 | len += msgs[i].len; |
| 161 | |
| 162 | if (len != size) |
| 163 | return -EINVAL; |
| 164 | |
| 165 | for (i = 0; i < num; i++) { |
| 166 | if (msgs[i].flags & I2C_M_RD) { |
| 167 | memcpy(msgs[i].buf, buf + pos, msgs[i].len); |
| 168 | pos += msgs[i].len; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | static int tegra_bpmp_i2c_msg_len_check(struct i2c_msg *msgs, unsigned int num) |
| 176 | { |
| 177 | size_t tx_len = 0, rx_len = 0; |
| 178 | unsigned int i; |
| 179 | |
| 180 | for (i = 0; i < num; i++) |
| 181 | if (!(msgs[i].flags & I2C_M_RD)) |
| 182 | tx_len += SERIALI2C_HDR_SIZE + msgs[i].len; |
| 183 | |
| 184 | if (tx_len > TEGRA_I2C_IPC_MAX_IN_BUF_SIZE) |
| 185 | return -EINVAL; |
| 186 | |
| 187 | for (i = 0; i < num; i++) |
| 188 | if ((msgs[i].flags & I2C_M_RD)) |
| 189 | rx_len += msgs[i].len; |
| 190 | |
| 191 | if (rx_len > TEGRA_I2C_IPC_MAX_OUT_BUF_SIZE) |
| 192 | return -EINVAL; |
| 193 | |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c, |
| 198 | struct mrq_i2c_request *request, |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 199 | struct mrq_i2c_response *response, |
| 200 | bool atomic) |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 201 | { |
| 202 | struct tegra_bpmp_message msg; |
| 203 | int err; |
| 204 | |
| 205 | request->cmd = CMD_I2C_XFER; |
| 206 | request->xfer.bus_id = i2c->bus; |
| 207 | |
| 208 | memset(&msg, 0, sizeof(msg)); |
| 209 | msg.mrq = MRQ_I2C; |
| 210 | msg.tx.data = request; |
| 211 | msg.tx.size = sizeof(*request); |
| 212 | msg.rx.data = response; |
| 213 | msg.rx.size = sizeof(*response); |
| 214 | |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 215 | if (atomic) |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 216 | err = tegra_bpmp_transfer_atomic(i2c->bpmp, &msg); |
| 217 | else |
| 218 | err = tegra_bpmp_transfer(i2c->bpmp, &msg); |
| 219 | |
| 220 | return err; |
| 221 | } |
| 222 | |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 223 | static int tegra_bpmp_i2c_xfer_common(struct i2c_adapter *adapter, |
| 224 | struct i2c_msg *msgs, int num, |
| 225 | bool atomic) |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 226 | { |
| 227 | struct tegra_bpmp_i2c *i2c = i2c_get_adapdata(adapter); |
| 228 | struct mrq_i2c_response response; |
| 229 | struct mrq_i2c_request request; |
| 230 | int err; |
| 231 | |
| 232 | err = tegra_bpmp_i2c_msg_len_check(msgs, num); |
| 233 | if (err < 0) { |
| 234 | dev_err(i2c->dev, "unsupported message length\n"); |
| 235 | return err; |
| 236 | } |
| 237 | |
| 238 | memset(&request, 0, sizeof(request)); |
| 239 | memset(&response, 0, sizeof(response)); |
| 240 | |
| 241 | err = tegra_bpmp_serialize_i2c_msg(i2c, &request, msgs, num); |
| 242 | if (err < 0) { |
| 243 | dev_err(i2c->dev, "failed to serialize message: %d\n", err); |
| 244 | return err; |
| 245 | } |
| 246 | |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 247 | err = tegra_bpmp_i2c_msg_xfer(i2c, &request, &response, atomic); |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 248 | if (err < 0) { |
| 249 | dev_err(i2c->dev, "failed to transfer message: %d\n", err); |
| 250 | return err; |
| 251 | } |
| 252 | |
| 253 | err = tegra_bpmp_i2c_deserialize(i2c, &response, msgs, num); |
| 254 | if (err < 0) { |
| 255 | dev_err(i2c->dev, "failed to deserialize message: %d\n", err); |
| 256 | return err; |
| 257 | } |
| 258 | |
| 259 | return num; |
| 260 | } |
| 261 | |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 262 | static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter, |
| 263 | struct i2c_msg *msgs, int num) |
| 264 | { |
| 265 | return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, false); |
| 266 | } |
| 267 | |
| 268 | static int tegra_bpmp_i2c_xfer_atomic(struct i2c_adapter *adapter, |
| 269 | struct i2c_msg *msgs, int num) |
| 270 | { |
| 271 | return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, true); |
| 272 | } |
| 273 | |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 274 | static u32 tegra_bpmp_i2c_func(struct i2c_adapter *adapter) |
| 275 | { |
| 276 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR | |
| 277 | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART; |
| 278 | } |
| 279 | |
| 280 | static const struct i2c_algorithm tegra_bpmp_i2c_algo = { |
| 281 | .master_xfer = tegra_bpmp_i2c_xfer, |
Wolfram Sang | 08960b0 | 2019-04-03 14:40:14 +0200 | [diff] [blame] | 282 | .master_xfer_atomic = tegra_bpmp_i2c_xfer_atomic, |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 283 | .functionality = tegra_bpmp_i2c_func, |
| 284 | }; |
| 285 | |
| 286 | static int tegra_bpmp_i2c_probe(struct platform_device *pdev) |
| 287 | { |
| 288 | struct tegra_bpmp_i2c *i2c; |
| 289 | u32 value; |
| 290 | int err; |
| 291 | |
| 292 | i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); |
| 293 | if (!i2c) |
| 294 | return -ENOMEM; |
| 295 | |
| 296 | i2c->dev = &pdev->dev; |
| 297 | |
| 298 | i2c->bpmp = dev_get_drvdata(pdev->dev.parent); |
| 299 | if (!i2c->bpmp) |
| 300 | return -ENODEV; |
| 301 | |
| 302 | err = of_property_read_u32(pdev->dev.of_node, "nvidia,bpmp-bus-id", |
| 303 | &value); |
| 304 | if (err < 0) |
| 305 | return err; |
| 306 | |
| 307 | i2c->bus = value; |
| 308 | |
| 309 | i2c_set_adapdata(&i2c->adapter, i2c); |
| 310 | i2c->adapter.owner = THIS_MODULE; |
| 311 | strlcpy(i2c->adapter.name, "Tegra BPMP I2C adapter", |
| 312 | sizeof(i2c->adapter.name)); |
| 313 | i2c->adapter.algo = &tegra_bpmp_i2c_algo; |
| 314 | i2c->adapter.dev.parent = &pdev->dev; |
| 315 | i2c->adapter.dev.of_node = pdev->dev.of_node; |
| 316 | |
| 317 | platform_set_drvdata(pdev, i2c); |
| 318 | |
| 319 | return i2c_add_adapter(&i2c->adapter); |
| 320 | } |
| 321 | |
| 322 | static int tegra_bpmp_i2c_remove(struct platform_device *pdev) |
| 323 | { |
| 324 | struct tegra_bpmp_i2c *i2c = platform_get_drvdata(pdev); |
| 325 | |
| 326 | i2c_del_adapter(&i2c->adapter); |
| 327 | |
| 328 | return 0; |
| 329 | } |
| 330 | |
| 331 | static const struct of_device_id tegra_bpmp_i2c_of_match[] = { |
| 332 | { .compatible = "nvidia,tegra186-bpmp-i2c", }, |
| 333 | { } |
| 334 | }; |
| 335 | MODULE_DEVICE_TABLE(of, tegra_bpmp_i2c_of_match); |
| 336 | |
| 337 | static struct platform_driver tegra_bpmp_i2c_driver = { |
| 338 | .driver = { |
| 339 | .name = "tegra-bpmp-i2c", |
| 340 | .of_match_table = tegra_bpmp_i2c_of_match, |
| 341 | }, |
| 342 | .probe = tegra_bpmp_i2c_probe, |
| 343 | .remove = tegra_bpmp_i2c_remove, |
| 344 | }; |
| 345 | module_platform_driver(tegra_bpmp_i2c_driver); |
| 346 | |
Colin Ian King | 8c91fd5ee | 2017-04-21 07:56:53 +0100 | [diff] [blame] | 347 | MODULE_DESCRIPTION("NVIDIA Tegra BPMP I2C bus controller driver"); |
Shardar Shariff Md | 0297ffa | 2017-02-20 17:52:34 +0100 | [diff] [blame] | 348 | MODULE_AUTHOR("Shardar Shariff Md <smohammed@nvidia.com>"); |
| 349 | MODULE_AUTHOR("Juha-Matti Tilli"); |
| 350 | MODULE_LICENSE("GPL v2"); |