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d5bb994b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
47083450 NG |
2 | /* |
3 | * IBM OPAL I2C driver | |
4 | * Copyright (C) 2014 IBM | |
47083450 NG |
5 | */ |
6 | ||
7 | #include <linux/device.h> | |
8 | #include <linux/i2c.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/of.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/slab.h> | |
15 | ||
16 | #include <asm/firmware.h> | |
17 | #include <asm/opal.h> | |
18 | ||
19 | static int i2c_opal_translate_error(int rc) | |
20 | { | |
21 | switch (rc) { | |
22 | case OPAL_NO_MEM: | |
23 | return -ENOMEM; | |
24 | case OPAL_PARAMETER: | |
25 | return -EINVAL; | |
26 | case OPAL_I2C_ARBT_LOST: | |
27 | return -EAGAIN; | |
28 | case OPAL_I2C_TIMEOUT: | |
29 | return -ETIMEDOUT; | |
30 | case OPAL_I2C_NACK_RCVD: | |
31 | return -ENXIO; | |
32 | case OPAL_I2C_STOP_ERR: | |
33 | return -EBUSY; | |
34 | default: | |
35 | return -EIO; | |
36 | } | |
37 | } | |
38 | ||
39 | static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req) | |
40 | { | |
41 | struct opal_msg msg; | |
42 | int token, rc; | |
43 | ||
44 | token = opal_async_get_token_interruptible(); | |
45 | if (token < 0) { | |
46 | if (token != -ERESTARTSYS) | |
47 | pr_err("Failed to get the async token\n"); | |
48 | ||
49 | return token; | |
50 | } | |
51 | ||
52 | rc = opal_i2c_request(token, bus_id, req); | |
53 | if (rc != OPAL_ASYNC_COMPLETION) { | |
54 | rc = i2c_opal_translate_error(rc); | |
55 | goto exit; | |
56 | } | |
57 | ||
58 | rc = opal_async_wait_response(token, &msg); | |
59 | if (rc) | |
60 | goto exit; | |
61 | ||
d0226d31 | 62 | rc = opal_get_async_rc(msg); |
47083450 NG |
63 | if (rc != OPAL_SUCCESS) { |
64 | rc = i2c_opal_translate_error(rc); | |
65 | goto exit; | |
66 | } | |
67 | ||
68 | exit: | |
69 | opal_async_release_token(token); | |
70 | return rc; | |
71 | } | |
72 | ||
73 | static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
74 | int num) | |
75 | { | |
76 | unsigned long opal_id = (unsigned long)adap->algo_data; | |
77 | struct opal_i2c_request req; | |
78 | int rc, i; | |
79 | ||
80 | /* We only support fairly simple combinations here of one | |
81 | * or two messages | |
82 | */ | |
83 | memset(&req, 0, sizeof(req)); | |
84 | switch(num) { | |
47083450 NG |
85 | case 1: |
86 | req.type = (msgs[0].flags & I2C_M_RD) ? | |
87 | OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; | |
88 | req.addr = cpu_to_be16(msgs[0].addr); | |
89 | req.size = cpu_to_be32(msgs[0].len); | |
90 | req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf)); | |
91 | break; | |
92 | case 2: | |
bf070380 NG |
93 | req.type = (msgs[1].flags & I2C_M_RD) ? |
94 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; | |
47083450 NG |
95 | req.addr = cpu_to_be16(msgs[0].addr); |
96 | req.subaddr_sz = msgs[0].len; | |
97 | for (i = 0; i < msgs[0].len; i++) | |
98 | req.subaddr = (req.subaddr << 8) | msgs[0].buf[i]; | |
99 | req.subaddr = cpu_to_be32(req.subaddr); | |
100 | req.size = cpu_to_be32(msgs[1].len); | |
101 | req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf)); | |
102 | break; | |
47083450 NG |
103 | } |
104 | ||
105 | rc = i2c_opal_send_request(opal_id, &req); | |
106 | if (rc) | |
107 | return rc; | |
108 | ||
109 | return num; | |
110 | } | |
111 | ||
112 | static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr, | |
113 | unsigned short flags, char read_write, | |
114 | u8 command, int size, union i2c_smbus_data *data) | |
115 | { | |
116 | unsigned long opal_id = (unsigned long)adap->algo_data; | |
117 | struct opal_i2c_request req; | |
118 | u8 local[2]; | |
119 | int rc; | |
120 | ||
121 | memset(&req, 0, sizeof(req)); | |
122 | ||
123 | req.addr = cpu_to_be16(addr); | |
124 | switch (size) { | |
125 | case I2C_SMBUS_BYTE: | |
126 | req.buffer_ra = cpu_to_be64(__pa(&data->byte)); | |
127 | req.size = cpu_to_be32(1); | |
128 | /* Fall through */ | |
129 | case I2C_SMBUS_QUICK: | |
130 | req.type = (read_write == I2C_SMBUS_READ) ? | |
131 | OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE; | |
132 | break; | |
133 | case I2C_SMBUS_BYTE_DATA: | |
134 | req.buffer_ra = cpu_to_be64(__pa(&data->byte)); | |
135 | req.size = cpu_to_be32(1); | |
136 | req.subaddr = cpu_to_be32(command); | |
137 | req.subaddr_sz = 1; | |
138 | req.type = (read_write == I2C_SMBUS_READ) ? | |
139 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; | |
140 | break; | |
141 | case I2C_SMBUS_WORD_DATA: | |
142 | if (!read_write) { | |
143 | local[0] = data->word & 0xff; | |
144 | local[1] = (data->word >> 8) & 0xff; | |
145 | } | |
146 | req.buffer_ra = cpu_to_be64(__pa(local)); | |
147 | req.size = cpu_to_be32(2); | |
148 | req.subaddr = cpu_to_be32(command); | |
149 | req.subaddr_sz = 1; | |
150 | req.type = (read_write == I2C_SMBUS_READ) ? | |
151 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; | |
152 | break; | |
153 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
154 | req.buffer_ra = cpu_to_be64(__pa(&data->block[1])); | |
155 | req.size = cpu_to_be32(data->block[0]); | |
156 | req.subaddr = cpu_to_be32(command); | |
157 | req.subaddr_sz = 1; | |
158 | req.type = (read_write == I2C_SMBUS_READ) ? | |
159 | OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE; | |
160 | break; | |
161 | default: | |
162 | return -EINVAL; | |
163 | } | |
164 | ||
165 | rc = i2c_opal_send_request(opal_id, &req); | |
166 | if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) { | |
167 | data->word = ((u16)local[1]) << 8; | |
168 | data->word |= local[0]; | |
169 | } | |
170 | ||
171 | return rc; | |
172 | } | |
173 | ||
174 | static u32 i2c_opal_func(struct i2c_adapter *adapter) | |
175 | { | |
176 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | | |
177 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | | |
178 | I2C_FUNC_SMBUS_I2C_BLOCK; | |
179 | } | |
180 | ||
181 | static const struct i2c_algorithm i2c_opal_algo = { | |
182 | .master_xfer = i2c_opal_master_xfer, | |
183 | .smbus_xfer = i2c_opal_smbus_xfer, | |
184 | .functionality = i2c_opal_func, | |
185 | }; | |
186 | ||
bf070380 NG |
187 | /* |
188 | * For two messages, we basically support simple smbus transactions of a | |
189 | * write-then-anything. | |
a531afdf | 190 | */ |
ae3923a2 | 191 | static const struct i2c_adapter_quirks i2c_opal_quirks = { |
bf070380 | 192 | .flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR, |
a531afdf WS |
193 | .max_comb_1st_msg_len = 4, |
194 | }; | |
195 | ||
47083450 NG |
196 | static int i2c_opal_probe(struct platform_device *pdev) |
197 | { | |
198 | struct i2c_adapter *adapter; | |
199 | const char *pname; | |
200 | u32 opal_id; | |
201 | int rc; | |
202 | ||
203 | if (!pdev->dev.of_node) | |
204 | return -ENODEV; | |
205 | ||
206 | rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id); | |
207 | if (rc) { | |
208 | dev_err(&pdev->dev, "Missing ibm,opal-id property !\n"); | |
209 | return -EIO; | |
210 | } | |
211 | ||
212 | adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL); | |
213 | if (!adapter) | |
214 | return -ENOMEM; | |
215 | ||
216 | adapter->algo = &i2c_opal_algo; | |
217 | adapter->algo_data = (void *)(unsigned long)opal_id; | |
a531afdf | 218 | adapter->quirks = &i2c_opal_quirks; |
47083450 NG |
219 | adapter->dev.parent = &pdev->dev; |
220 | adapter->dev.of_node = of_node_get(pdev->dev.of_node); | |
221 | pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL); | |
222 | if (pname) | |
223 | strlcpy(adapter->name, pname, sizeof(adapter->name)); | |
224 | else | |
225 | strlcpy(adapter->name, "opal", sizeof(adapter->name)); | |
226 | ||
227 | platform_set_drvdata(pdev, adapter); | |
228 | rc = i2c_add_adapter(adapter); | |
229 | if (rc) | |
230 | dev_err(&pdev->dev, "Failed to register the i2c adapter\n"); | |
231 | ||
232 | return rc; | |
233 | } | |
234 | ||
235 | static int i2c_opal_remove(struct platform_device *pdev) | |
236 | { | |
237 | struct i2c_adapter *adapter = platform_get_drvdata(pdev); | |
238 | ||
239 | i2c_del_adapter(adapter); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static const struct of_device_id i2c_opal_of_match[] = { | |
245 | { | |
246 | .compatible = "ibm,opal-i2c", | |
247 | }, | |
248 | { } | |
249 | }; | |
250 | MODULE_DEVICE_TABLE(of, i2c_opal_of_match); | |
251 | ||
252 | static struct platform_driver i2c_opal_driver = { | |
253 | .probe = i2c_opal_probe, | |
254 | .remove = i2c_opal_remove, | |
255 | .driver = { | |
256 | .name = "i2c-opal", | |
257 | .of_match_table = i2c_opal_of_match, | |
258 | }, | |
259 | }; | |
260 | ||
261 | static int __init i2c_opal_init(void) | |
262 | { | |
263 | if (!firmware_has_feature(FW_FEATURE_OPAL)) | |
264 | return -ENODEV; | |
265 | ||
266 | return platform_driver_register(&i2c_opal_driver); | |
267 | } | |
268 | module_init(i2c_opal_init); | |
269 | ||
270 | static void __exit i2c_opal_exit(void) | |
271 | { | |
272 | return platform_driver_unregister(&i2c_opal_driver); | |
273 | } | |
274 | module_exit(i2c_opal_exit); | |
275 | ||
276 | MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>"); | |
277 | MODULE_DESCRIPTION("IBM OPAL I2C driver"); | |
278 | MODULE_LICENSE("GPL"); |