Neelesh Gupta | 4708345 | 2014-12-13 23:31:05 +0530 | [diff] [blame] | 1 | /* |
| 2 | * IBM OPAL I2C driver |
| 3 | * Copyright (C) 2014 IBM |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/device.h> |
| 20 | #include <linux/i2c.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/mm.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/of.h> |
| 25 | #include <linux/platform_device.h> |
| 26 | #include <linux/slab.h> |
| 27 | |
| 28 | #include <asm/firmware.h> |
| 29 | #include <asm/opal.h> |
| 30 | |
| 31 | static int i2c_opal_translate_error(int rc) |
| 32 | { |
| 33 | switch (rc) { |
| 34 | case OPAL_NO_MEM: |
| 35 | return -ENOMEM; |
| 36 | case OPAL_PARAMETER: |
| 37 | return -EINVAL; |
| 38 | case OPAL_I2C_ARBT_LOST: |
| 39 | return -EAGAIN; |
| 40 | case OPAL_I2C_TIMEOUT: |
| 41 | return -ETIMEDOUT; |
| 42 | case OPAL_I2C_NACK_RCVD: |
| 43 | return -ENXIO; |
| 44 | case OPAL_I2C_STOP_ERR: |
| 45 | return -EBUSY; |
| 46 | default: |
| 47 | return -EIO; |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req) |
| 52 | { |
| 53 | struct opal_msg msg; |
| 54 | int token, rc; |
| 55 | |
| 56 | token = opal_async_get_token_interruptible(); |
| 57 | if (token < 0) { |
| 58 | if (token != -ERESTARTSYS) |
| 59 | pr_err("Failed to get the async token\n"); |
| 60 | |
| 61 | return token; |
| 62 | } |
| 63 | |
| 64 | rc = opal_i2c_request(token, bus_id, req); |
| 65 | if (rc != OPAL_ASYNC_COMPLETION) { |
| 66 | rc = i2c_opal_translate_error(rc); |
| 67 | goto exit; |
| 68 | } |
| 69 | |
| 70 | rc = opal_async_wait_response(token, &msg); |
| 71 | if (rc) |
| 72 | goto exit; |
| 73 | |
Suraj Jitindar Singh | d0226d3 | 2016-06-29 13:38:38 +1000 | [diff] [blame] | 74 | rc = opal_get_async_rc(msg); |
Neelesh Gupta | 4708345 | 2014-12-13 23:31:05 +0530 | [diff] [blame] | 75 | if (rc != OPAL_SUCCESS) { |
| 76 | rc = i2c_opal_translate_error(rc); |
| 77 | goto exit; |
| 78 | } |
| 79 | |
| 80 | exit: |
| 81 | opal_async_release_token(token); |
| 82 | return rc; |
| 83 | } |
| 84 | |
| 85 | static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, |
| 86 | int num) |
| 87 | { |
| 88 | unsigned long opal_id = (unsigned long)adap->algo_data; |
| 89 | struct opal_i2c_request req; |
| 90 | int rc, i; |
| 91 | |
| 92 | /* We only support fairly simple combinations here of one |
| 93 | * or two messages |
| 94 | */ |
| 95 | memset(&req, 0, sizeof(req)); |
| 96 | switch(num) { |
| 97 | case 0: |
| 98 | return 0; |
| 99 | case 1: |
| 100 | req.type = (msgs[0].flags & I2C_M_RD) ? |
| 101 | OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; |
| 102 | req.addr = cpu_to_be16(msgs[0].addr); |
| 103 | req.size = cpu_to_be32(msgs[0].len); |
| 104 | req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf)); |
| 105 | break; |
| 106 | case 2: |
Neelesh Gupta | bf07038 | 2015-03-13 15:25:33 +0100 | [diff] [blame] | 107 | req.type = (msgs[1].flags & I2C_M_RD) ? |
| 108 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; |
Neelesh Gupta | 4708345 | 2014-12-13 23:31:05 +0530 | [diff] [blame] | 109 | req.addr = cpu_to_be16(msgs[0].addr); |
| 110 | req.subaddr_sz = msgs[0].len; |
| 111 | for (i = 0; i < msgs[0].len; i++) |
| 112 | req.subaddr = (req.subaddr << 8) | msgs[0].buf[i]; |
| 113 | req.subaddr = cpu_to_be32(req.subaddr); |
| 114 | req.size = cpu_to_be32(msgs[1].len); |
| 115 | req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf)); |
| 116 | break; |
| 117 | default: |
| 118 | return -EOPNOTSUPP; |
| 119 | } |
| 120 | |
| 121 | rc = i2c_opal_send_request(opal_id, &req); |
| 122 | if (rc) |
| 123 | return rc; |
| 124 | |
| 125 | return num; |
| 126 | } |
| 127 | |
| 128 | static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr, |
| 129 | unsigned short flags, char read_write, |
| 130 | u8 command, int size, union i2c_smbus_data *data) |
| 131 | { |
| 132 | unsigned long opal_id = (unsigned long)adap->algo_data; |
| 133 | struct opal_i2c_request req; |
| 134 | u8 local[2]; |
| 135 | int rc; |
| 136 | |
| 137 | memset(&req, 0, sizeof(req)); |
| 138 | |
| 139 | req.addr = cpu_to_be16(addr); |
| 140 | switch (size) { |
| 141 | case I2C_SMBUS_BYTE: |
| 142 | req.buffer_ra = cpu_to_be64(__pa(&data->byte)); |
| 143 | req.size = cpu_to_be32(1); |
| 144 | /* Fall through */ |
| 145 | case I2C_SMBUS_QUICK: |
| 146 | req.type = (read_write == I2C_SMBUS_READ) ? |
| 147 | OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; |
| 148 | break; |
| 149 | case I2C_SMBUS_BYTE_DATA: |
| 150 | req.buffer_ra = cpu_to_be64(__pa(&data->byte)); |
| 151 | req.size = cpu_to_be32(1); |
| 152 | req.subaddr = cpu_to_be32(command); |
| 153 | req.subaddr_sz = 1; |
| 154 | req.type = (read_write == I2C_SMBUS_READ) ? |
| 155 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; |
| 156 | break; |
| 157 | case I2C_SMBUS_WORD_DATA: |
| 158 | if (!read_write) { |
| 159 | local[0] = data->word & 0xff; |
| 160 | local[1] = (data->word >> 8) & 0xff; |
| 161 | } |
| 162 | req.buffer_ra = cpu_to_be64(__pa(local)); |
| 163 | req.size = cpu_to_be32(2); |
| 164 | req.subaddr = cpu_to_be32(command); |
| 165 | req.subaddr_sz = 1; |
| 166 | req.type = (read_write == I2C_SMBUS_READ) ? |
| 167 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; |
| 168 | break; |
| 169 | case I2C_SMBUS_I2C_BLOCK_DATA: |
| 170 | req.buffer_ra = cpu_to_be64(__pa(&data->block[1])); |
| 171 | req.size = cpu_to_be32(data->block[0]); |
| 172 | req.subaddr = cpu_to_be32(command); |
| 173 | req.subaddr_sz = 1; |
| 174 | req.type = (read_write == I2C_SMBUS_READ) ? |
| 175 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; |
| 176 | break; |
| 177 | default: |
| 178 | return -EINVAL; |
| 179 | } |
| 180 | |
| 181 | rc = i2c_opal_send_request(opal_id, &req); |
| 182 | if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) { |
| 183 | data->word = ((u16)local[1]) << 8; |
| 184 | data->word |= local[0]; |
| 185 | } |
| 186 | |
| 187 | return rc; |
| 188 | } |
| 189 | |
| 190 | static u32 i2c_opal_func(struct i2c_adapter *adapter) |
| 191 | { |
| 192 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | |
| 193 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | |
| 194 | I2C_FUNC_SMBUS_I2C_BLOCK; |
| 195 | } |
| 196 | |
| 197 | static const struct i2c_algorithm i2c_opal_algo = { |
| 198 | .master_xfer = i2c_opal_master_xfer, |
| 199 | .smbus_xfer = i2c_opal_smbus_xfer, |
| 200 | .functionality = i2c_opal_func, |
| 201 | }; |
| 202 | |
Neelesh Gupta | bf07038 | 2015-03-13 15:25:33 +0100 | [diff] [blame] | 203 | /* |
| 204 | * For two messages, we basically support simple smbus transactions of a |
| 205 | * write-then-anything. |
Wolfram Sang | a531afd | 2015-01-07 12:24:10 +0100 | [diff] [blame] | 206 | */ |
Bhumika Goyal | ae3923a | 2017-08-21 17:42:04 +0530 | [diff] [blame^] | 207 | static const struct i2c_adapter_quirks i2c_opal_quirks = { |
Neelesh Gupta | bf07038 | 2015-03-13 15:25:33 +0100 | [diff] [blame] | 208 | .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR, |
Wolfram Sang | a531afd | 2015-01-07 12:24:10 +0100 | [diff] [blame] | 209 | .max_comb_1st_msg_len = 4, |
| 210 | }; |
| 211 | |
Neelesh Gupta | 4708345 | 2014-12-13 23:31:05 +0530 | [diff] [blame] | 212 | static int i2c_opal_probe(struct platform_device *pdev) |
| 213 | { |
| 214 | struct i2c_adapter *adapter; |
| 215 | const char *pname; |
| 216 | u32 opal_id; |
| 217 | int rc; |
| 218 | |
| 219 | if (!pdev->dev.of_node) |
| 220 | return -ENODEV; |
| 221 | |
| 222 | rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id); |
| 223 | if (rc) { |
| 224 | dev_err(&pdev->dev, "Missing ibm,opal-id property !\n"); |
| 225 | return -EIO; |
| 226 | } |
| 227 | |
| 228 | adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL); |
| 229 | if (!adapter) |
| 230 | return -ENOMEM; |
| 231 | |
| 232 | adapter->algo = &i2c_opal_algo; |
| 233 | adapter->algo_data = (void *)(unsigned long)opal_id; |
Wolfram Sang | a531afd | 2015-01-07 12:24:10 +0100 | [diff] [blame] | 234 | adapter->quirks = &i2c_opal_quirks; |
Neelesh Gupta | 4708345 | 2014-12-13 23:31:05 +0530 | [diff] [blame] | 235 | adapter->dev.parent = &pdev->dev; |
| 236 | adapter->dev.of_node = of_node_get(pdev->dev.of_node); |
| 237 | pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL); |
| 238 | if (pname) |
| 239 | strlcpy(adapter->name, pname, sizeof(adapter->name)); |
| 240 | else |
| 241 | strlcpy(adapter->name, "opal", sizeof(adapter->name)); |
| 242 | |
| 243 | platform_set_drvdata(pdev, adapter); |
| 244 | rc = i2c_add_adapter(adapter); |
| 245 | if (rc) |
| 246 | dev_err(&pdev->dev, "Failed to register the i2c adapter\n"); |
| 247 | |
| 248 | return rc; |
| 249 | } |
| 250 | |
| 251 | static int i2c_opal_remove(struct platform_device *pdev) |
| 252 | { |
| 253 | struct i2c_adapter *adapter = platform_get_drvdata(pdev); |
| 254 | |
| 255 | i2c_del_adapter(adapter); |
| 256 | |
| 257 | return 0; |
| 258 | } |
| 259 | |
| 260 | static const struct of_device_id i2c_opal_of_match[] = { |
| 261 | { |
| 262 | .compatible = "ibm,opal-i2c", |
| 263 | }, |
| 264 | { } |
| 265 | }; |
| 266 | MODULE_DEVICE_TABLE(of, i2c_opal_of_match); |
| 267 | |
| 268 | static struct platform_driver i2c_opal_driver = { |
| 269 | .probe = i2c_opal_probe, |
| 270 | .remove = i2c_opal_remove, |
| 271 | .driver = { |
| 272 | .name = "i2c-opal", |
| 273 | .of_match_table = i2c_opal_of_match, |
| 274 | }, |
| 275 | }; |
| 276 | |
| 277 | static int __init i2c_opal_init(void) |
| 278 | { |
| 279 | if (!firmware_has_feature(FW_FEATURE_OPAL)) |
| 280 | return -ENODEV; |
| 281 | |
| 282 | return platform_driver_register(&i2c_opal_driver); |
| 283 | } |
| 284 | module_init(i2c_opal_init); |
| 285 | |
| 286 | static void __exit i2c_opal_exit(void) |
| 287 | { |
| 288 | return platform_driver_unregister(&i2c_opal_driver); |
| 289 | } |
| 290 | module_exit(i2c_opal_exit); |
| 291 | |
| 292 | MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); |
| 293 | MODULE_DESCRIPTION("IBM OPAL I2C driver"); |
| 294 | MODULE_LICENSE("GPL"); |