1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 i2c Support for Apple SMU Controller
4
5 Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
6 <benh@kernel.crashing.org>
7
8
9 */
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/i2c.h>
15 #include <linux/device.h>
16 #include <linux/platform_device.h>
17 #include <linux/of_irq.h>
18 #include <asm/prom.h>
19 #include <asm/pmac_low_i2c.h>
20
21 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
22 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
23 MODULE_LICENSE("GPL");
24
25 /*
26 * SMBUS-type transfer entrypoint
27 */
i2c_powermac_smbus_xfer(struct i2c_adapter * adap,u16 addr,unsigned short flags,char read_write,u8 command,int size,union i2c_smbus_data * data)28 static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap,
29 u16 addr,
30 unsigned short flags,
31 char read_write,
32 u8 command,
33 int size,
34 union i2c_smbus_data* data)
35 {
36 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
37 int rc = 0;
38 int read = (read_write == I2C_SMBUS_READ);
39 int addrdir = (addr << 1) | read;
40 int mode, subsize, len;
41 u32 subaddr;
42 u8 *buf;
43 u8 local[2];
44
45 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
46 mode = pmac_i2c_mode_std;
47 subsize = 0;
48 subaddr = 0;
49 } else {
50 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
51 subsize = 1;
52 subaddr = command;
53 }
54
55 switch (size) {
56 case I2C_SMBUS_QUICK:
57 buf = NULL;
58 len = 0;
59 break;
60 case I2C_SMBUS_BYTE:
61 case I2C_SMBUS_BYTE_DATA:
62 buf = &data->byte;
63 len = 1;
64 break;
65 case I2C_SMBUS_WORD_DATA:
66 if (!read) {
67 local[0] = data->word & 0xff;
68 local[1] = (data->word >> 8) & 0xff;
69 }
70 buf = local;
71 len = 2;
72 break;
73
74 /* Note that these are broken vs. the expected smbus API where
75 * on reads, the length is actually returned from the function,
76 * but I think the current API makes no sense and I don't want
77 * any driver that I haven't verified for correctness to go
78 * anywhere near a pmac i2c bus anyway ...
79 */
80 case I2C_SMBUS_BLOCK_DATA:
81 buf = data->block;
82 len = data->block[0] + 1;
83 break;
84 case I2C_SMBUS_I2C_BLOCK_DATA:
85 buf = &data->block[1];
86 len = data->block[0];
87 break;
88
89 default:
90 return -EINVAL;
91 }
92
93 rc = pmac_i2c_open(bus, 0);
94 if (rc) {
95 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
96 return rc;
97 }
98
99 rc = pmac_i2c_setmode(bus, mode);
100 if (rc) {
101 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
102 mode, rc);
103 goto bail;
104 }
105
106 rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
107 if (rc) {
108 if (rc == -ENXIO)
109 dev_dbg(&adap->dev,
110 "I2C transfer at 0x%02x failed, size %d, "
111 "err %d\n", addrdir >> 1, size, rc);
112 else
113 dev_err(&adap->dev,
114 "I2C transfer at 0x%02x failed, size %d, "
115 "err %d\n", addrdir >> 1, size, rc);
116 goto bail;
117 }
118
119 if (size == I2C_SMBUS_WORD_DATA && read) {
120 data->word = ((u16)local[1]) << 8;
121 data->word |= local[0];
122 }
123
124 bail:
125 pmac_i2c_close(bus);
126 return rc;
127 }
128
129 /*
130 * Generic i2c master transfer entrypoint. This driver only support single
131 * messages (for "lame i2c" transfers). Anything else should use the smbus
132 * entry point
133 */
i2c_powermac_master_xfer(struct i2c_adapter * adap,struct i2c_msg * msgs,int num)134 static int i2c_powermac_master_xfer( struct i2c_adapter *adap,
135 struct i2c_msg *msgs,
136 int num)
137 {
138 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
139 int rc = 0;
140 int addrdir;
141
142 if (msgs->flags & I2C_M_TEN)
143 return -EINVAL;
144 addrdir = i2c_8bit_addr_from_msg(msgs);
145
146 rc = pmac_i2c_open(bus, 0);
147 if (rc) {
148 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
149 return rc;
150 }
151 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
152 if (rc) {
153 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
154 pmac_i2c_mode_std, rc);
155 goto bail;
156 }
157 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
158 if (rc < 0) {
159 if (rc == -ENXIO)
160 dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
161 addrdir & 1 ? "read from" : "write to",
162 addrdir >> 1, rc);
163 else
164 dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
165 addrdir & 1 ? "read from" : "write to",
166 addrdir >> 1, rc);
167 }
168 bail:
169 pmac_i2c_close(bus);
170 return rc < 0 ? rc : 1;
171 }
172
i2c_powermac_func(struct i2c_adapter * adapter)173 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
174 {
175 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
176 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
177 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
178 }
179
180 /* For now, we only handle smbus */
181 static const struct i2c_algorithm i2c_powermac_algorithm = {
182 .smbus_xfer = i2c_powermac_smbus_xfer,
183 .master_xfer = i2c_powermac_master_xfer,
184 .functionality = i2c_powermac_func,
185 };
186
187 static const struct i2c_adapter_quirks i2c_powermac_quirks = {
188 .max_num_msgs = 1,
189 };
190
i2c_powermac_remove(struct platform_device * dev)191 static int i2c_powermac_remove(struct platform_device *dev)
192 {
193 struct i2c_adapter *adapter = platform_get_drvdata(dev);
194
195 i2c_del_adapter(adapter);
196 memset(adapter, 0, sizeof(*adapter));
197
198 return 0;
199 }
200
i2c_powermac_get_addr(struct i2c_adapter * adap,struct pmac_i2c_bus * bus,struct device_node * node)201 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
202 struct pmac_i2c_bus *bus,
203 struct device_node *node)
204 {
205 u32 prop;
206 int ret;
207
208 /* First check for valid "reg" */
209 ret = of_property_read_u32(node, "reg", &prop);
210 if (ret == 0)
211 return (prop & 0xff) >> 1;
212
213 /* Then check old-style "i2c-address" */
214 ret = of_property_read_u32(node, "i2c-address", &prop);
215 if (ret == 0)
216 return (prop & 0xff) >> 1;
217
218 /* Now handle some devices with missing "reg" properties */
219 if (of_node_name_eq(node, "cereal"))
220 return 0x60;
221 else if (of_node_name_eq(node, "deq"))
222 return 0x34;
223
224 dev_warn(&adap->dev, "No i2c address for %pOF\n", node);
225
226 return 0xffffffff;
227 }
228
i2c_powermac_create_one(struct i2c_adapter * adap,const char * type,u32 addr)229 static void i2c_powermac_create_one(struct i2c_adapter *adap,
230 const char *type,
231 u32 addr)
232 {
233 struct i2c_board_info info = {};
234 struct i2c_client *newdev;
235
236 strncpy(info.type, type, sizeof(info.type));
237 info.addr = addr;
238 newdev = i2c_new_client_device(adap, &info);
239 if (IS_ERR(newdev))
240 dev_err(&adap->dev,
241 "i2c-powermac: Failure to register missing %s\n",
242 type);
243 }
244
i2c_powermac_add_missing(struct i2c_adapter * adap,struct pmac_i2c_bus * bus,bool found_onyx)245 static void i2c_powermac_add_missing(struct i2c_adapter *adap,
246 struct pmac_i2c_bus *bus,
247 bool found_onyx)
248 {
249 struct device_node *busnode = pmac_i2c_get_bus_node(bus);
250 int rc;
251
252 /* Check for the onyx audio codec */
253 #define ONYX_REG_CONTROL 67
254 if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
255 union i2c_smbus_data data;
256
257 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
258 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
259 &data);
260 if (rc >= 0)
261 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
262
263 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
264 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
265 &data);
266 if (rc >= 0)
267 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
268 }
269 }
270
i2c_powermac_get_type(struct i2c_adapter * adap,struct device_node * node,u32 addr,char * type,int type_size)271 static bool i2c_powermac_get_type(struct i2c_adapter *adap,
272 struct device_node *node,
273 u32 addr, char *type, int type_size)
274 {
275 char tmp[16];
276
277 /*
278 * Note: we do _NOT_ want the standard i2c drivers to match with any of
279 * our powermac stuff unless they have been specifically modified to
280 * handle it on a case by case basis. For example, for thermal control,
281 * things like lm75 etc... shall match with their corresponding
282 * windfarm drivers, _NOT_ the generic ones, so we force a prefix of
283 * 'MAC', onto the modalias to make that happen
284 */
285
286 /* First try proper modalias */
287 if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
288 snprintf(type, type_size, "MAC,%s", tmp);
289 return true;
290 }
291
292 /* Now look for known workarounds */
293 if (of_node_name_eq(node, "deq")) {
294 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
295 if (addr == 0x34) {
296 snprintf(type, type_size, "MAC,tas3001");
297 return true;
298 } else if (addr == 0x35) {
299 snprintf(type, type_size, "MAC,tas3004");
300 return true;
301 }
302 }
303
304 dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node);
305 return false;
306 }
307
i2c_powermac_register_devices(struct i2c_adapter * adap,struct pmac_i2c_bus * bus)308 static void i2c_powermac_register_devices(struct i2c_adapter *adap,
309 struct pmac_i2c_bus *bus)
310 {
311 struct i2c_client *newdev;
312 struct device_node *node;
313 bool found_onyx = false;
314
315 /*
316 * In some cases we end up with the via-pmu node itself, in this
317 * case we skip this function completely as the device-tree will
318 * not contain anything useful.
319 */
320 if (of_node_name_eq(adap->dev.of_node, "via-pmu"))
321 return;
322
323 for_each_child_of_node(adap->dev.of_node, node) {
324 struct i2c_board_info info = {};
325 u32 addr;
326
327 /* Get address & channel */
328 addr = i2c_powermac_get_addr(adap, bus, node);
329 if (addr == 0xffffffff)
330 continue;
331
332 /* Multibus setup, check channel */
333 if (!pmac_i2c_match_adapter(node, adap))
334 continue;
335
336 dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node);
337
338 /*
339 * Keep track of some device existence to handle
340 * workarounds later.
341 */
342 if (of_device_is_compatible(node, "pcm3052"))
343 found_onyx = true;
344
345 /* Make up a modalias */
346 if (!i2c_powermac_get_type(adap, node, addr,
347 info.type, sizeof(info.type))) {
348 continue;
349 }
350
351 /* Fill out the rest of the info structure */
352 info.addr = addr;
353 info.irq = irq_of_parse_and_map(node, 0);
354 info.of_node = of_node_get(node);
355
356 newdev = i2c_new_client_device(adap, &info);
357 if (IS_ERR(newdev)) {
358 dev_err(&adap->dev, "i2c-powermac: Failure to register"
359 " %pOF\n", node);
360 of_node_put(node);
361 /* We do not dispose of the interrupt mapping on
362 * purpose. It's not necessary (interrupt cannot be
363 * re-used) and somebody else might have grabbed it
364 * via direct DT lookup so let's not bother
365 */
366 continue;
367 }
368 }
369
370 /* Additional workarounds */
371 i2c_powermac_add_missing(adap, bus, found_onyx);
372 }
373
i2c_powermac_probe(struct platform_device * dev)374 static int i2c_powermac_probe(struct platform_device *dev)
375 {
376 struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
377 struct device_node *parent;
378 struct i2c_adapter *adapter;
379 int rc;
380
381 if (bus == NULL)
382 return -EINVAL;
383 adapter = pmac_i2c_get_adapter(bus);
384
385 /* Ok, now we need to make up a name for the interface that will
386 * match what we used to do in the past, that is basically the
387 * controller's parent device node for keywest. PMU didn't have a
388 * naming convention and SMU has a different one
389 */
390 switch(pmac_i2c_get_type(bus)) {
391 case pmac_i2c_bus_keywest:
392 parent = of_get_parent(pmac_i2c_get_controller(bus));
393 if (parent == NULL)
394 return -EINVAL;
395 snprintf(adapter->name, sizeof(adapter->name), "%pOFn %d",
396 parent,
397 pmac_i2c_get_channel(bus));
398 of_node_put(parent);
399 break;
400 case pmac_i2c_bus_pmu:
401 snprintf(adapter->name, sizeof(adapter->name), "pmu %d",
402 pmac_i2c_get_channel(bus));
403 break;
404 case pmac_i2c_bus_smu:
405 /* This is not what we used to do but I'm fixing drivers at
406 * the same time as this change
407 */
408 snprintf(adapter->name, sizeof(adapter->name), "smu %d",
409 pmac_i2c_get_channel(bus));
410 break;
411 default:
412 return -EINVAL;
413 }
414
415 platform_set_drvdata(dev, adapter);
416 adapter->algo = &i2c_powermac_algorithm;
417 adapter->quirks = &i2c_powermac_quirks;
418 i2c_set_adapdata(adapter, bus);
419 adapter->dev.parent = &dev->dev;
420
421 /* Clear of_node to skip automatic registration of i2c child nodes */
422 adapter->dev.of_node = NULL;
423 rc = i2c_add_adapter(adapter);
424 if (rc) {
425 printk(KERN_ERR "i2c-powermac: Adapter %s registration "
426 "failed\n", adapter->name);
427 memset(adapter, 0, sizeof(*adapter));
428 return rc;
429 }
430
431 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
432
433 /* Use custom child registration due to Apple device-tree funkyness */
434 adapter->dev.of_node = dev->dev.of_node;
435 i2c_powermac_register_devices(adapter, bus);
436
437 return 0;
438 }
439
440 static struct platform_driver i2c_powermac_driver = {
441 .probe = i2c_powermac_probe,
442 .remove = i2c_powermac_remove,
443 .driver = {
444 .name = "i2c-powermac",
445 .bus = &platform_bus_type,
446 },
447 };
448
449 module_platform_driver(i2c_powermac_driver);
450
451 MODULE_ALIAS("platform:i2c-powermac");
452