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4d3d0e42 AJ |
1 | /* |
2 | * Copyright (C) 2016 IBM Corp. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | */ | |
9 | ||
10 | #include <linux/mfd/syscon.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/string.h> | |
14 | #include "../core.h" | |
15 | #include "pinctrl-aspeed.h" | |
16 | ||
17 | int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) | |
18 | { | |
19 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
20 | ||
21 | return pdata->ngroups; | |
22 | } | |
23 | ||
24 | const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev, | |
25 | unsigned int group) | |
26 | { | |
27 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
28 | ||
29 | return pdata->groups[group].name; | |
30 | } | |
31 | ||
32 | int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, | |
33 | unsigned int group, const unsigned int **pins, | |
34 | unsigned int *npins) | |
35 | { | |
36 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
37 | ||
38 | *pins = &pdata->groups[group].pins[0]; | |
39 | *npins = pdata->groups[group].npins; | |
40 | ||
41 | return 0; | |
42 | } | |
43 | ||
44 | void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev, | |
45 | struct seq_file *s, unsigned int offset) | |
46 | { | |
47 | seq_printf(s, " %s", dev_name(pctldev->dev)); | |
48 | } | |
49 | ||
50 | int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev) | |
51 | { | |
52 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
53 | ||
54 | return pdata->nfunctions; | |
55 | } | |
56 | ||
57 | const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev, | |
58 | unsigned int function) | |
59 | { | |
60 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
61 | ||
62 | return pdata->functions[function].name; | |
63 | } | |
64 | ||
65 | int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev, | |
66 | unsigned int function, | |
67 | const char * const **groups, | |
68 | unsigned int * const num_groups) | |
69 | { | |
70 | struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); | |
71 | ||
72 | *groups = pdata->functions[function].groups; | |
73 | *num_groups = pdata->functions[function].ngroups; | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | static inline void aspeed_sig_desc_print_val( | |
79 | const struct aspeed_sig_desc *desc, bool enable, u32 rv) | |
80 | { | |
81 | pr_debug("SCU%x[0x%08x]=0x%x, got 0x%x from 0x%08x\n", desc->reg, | |
82 | desc->mask, enable ? desc->enable : desc->disable, | |
83 | (rv & desc->mask) >> __ffs(desc->mask), rv); | |
84 | } | |
85 | ||
86 | /** | |
87 | * Query the enabled or disabled state of a signal descriptor | |
88 | * | |
89 | * @desc: The signal descriptor of interest | |
90 | * @enabled: True to query the enabled state, false to query disabled state | |
91 | * @regmap: The SCU regmap instance | |
92 | * | |
93 | * @return True if the descriptor's bitfield is configured to the state | |
94 | * selected by @enabled, false otherwise | |
95 | * | |
96 | * Evaluation of descriptor state is non-trivial in that it is not a binary | |
97 | * outcome: The bitfields can be greater than one bit in size and thus can take | |
98 | * a value that is neither the enabled nor disabled state recorded in the | |
99 | * descriptor (typically this means a different function to the one of interest | |
100 | * is enabled). Thus we must explicitly test for either condition as required. | |
101 | */ | |
102 | static bool aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, | |
103 | bool enabled, struct regmap *map) | |
104 | { | |
105 | unsigned int raw; | |
106 | u32 want; | |
107 | ||
108 | if (regmap_read(map, desc->reg, &raw) < 0) | |
109 | return false; | |
110 | ||
111 | aspeed_sig_desc_print_val(desc, enabled, raw); | |
112 | want = enabled ? desc->enable : desc->disable; | |
113 | ||
114 | return ((raw & desc->mask) >> __ffs(desc->mask)) == want; | |
115 | } | |
116 | ||
117 | /** | |
118 | * Query the enabled or disabled state for a mux function's signal on a pin | |
119 | * | |
120 | * @expr: An expression controlling the signal for a mux function on a pin | |
121 | * @enabled: True to query the enabled state, false to query disabled state | |
122 | * @regmap: The SCU regmap instance | |
123 | * | |
124 | * @return True if the expression composed by @enabled evaluates true, false | |
125 | * otherwise | |
126 | * | |
127 | * A mux function is enabled or disabled if the function's signal expression | |
128 | * for each pin in the function's pin group evaluates true for the desired | |
129 | * state. An signal expression evaluates true if all of its associated signal | |
130 | * descriptors evaluate true for the desired state. | |
131 | * | |
132 | * If an expression's state is described by more than one bit, either through | |
133 | * multi-bit bitfields in a single signal descriptor or through multiple signal | |
134 | * descriptors of a single bit then it is possible for the expression to be in | |
135 | * neither the enabled nor disabled state. Thus we must explicitly test for | |
136 | * either condition as required. | |
137 | */ | |
138 | static bool aspeed_sig_expr_eval(const struct aspeed_sig_expr *expr, | |
139 | bool enabled, struct regmap *map) | |
140 | { | |
141 | int i; | |
142 | ||
143 | for (i = 0; i < expr->ndescs; i++) { | |
144 | const struct aspeed_sig_desc *desc = &expr->descs[i]; | |
145 | ||
146 | if (!aspeed_sig_desc_eval(desc, enabled, map)) | |
147 | return false; | |
148 | } | |
149 | ||
150 | return true; | |
151 | } | |
152 | ||
153 | /** | |
154 | * Configure a pin's signal by applying an expression's descriptor state for | |
155 | * all descriptors in the expression. | |
156 | * | |
157 | * @expr: The expression associated with the function whose signal is to be | |
158 | * configured | |
159 | * @enable: true to enable an function's signal through a pin's signal | |
160 | * expression, false to disable the function's signal | |
161 | * @map: The SCU's regmap instance for pinmux register access. | |
162 | * | |
163 | * @return true if the expression is configured as requested, false otherwise | |
164 | */ | |
165 | static bool aspeed_sig_expr_set(const struct aspeed_sig_expr *expr, | |
166 | bool enable, struct regmap *map) | |
167 | { | |
168 | int i; | |
4d3d0e42 AJ |
169 | |
170 | for (i = 0; i < expr->ndescs; i++) { | |
5366f146 | 171 | bool ret; |
4d3d0e42 AJ |
172 | const struct aspeed_sig_desc *desc = &expr->descs[i]; |
173 | u32 pattern = enable ? desc->enable : desc->disable; | |
174 | ||
175 | /* | |
176 | * Strap registers are configured in hardware or by early-boot | |
177 | * firmware. Treat them as read-only despite that we can write | |
178 | * them. This may mean that certain functions cannot be | |
179 | * deconfigured and is the reason we re-evaluate after writing | |
180 | * all descriptor bits. | |
181 | */ | |
182 | if (desc->reg == HW_STRAP1 || desc->reg == HW_STRAP2) | |
183 | continue; | |
184 | ||
185 | ret = regmap_update_bits(map, desc->reg, desc->mask, | |
55956035 | 186 | pattern << __ffs(desc->mask)) == 0; |
4d3d0e42 | 187 | |
55956035 AB |
188 | if (!ret) |
189 | return ret; | |
4d3d0e42 AJ |
190 | } |
191 | ||
192 | return aspeed_sig_expr_eval(expr, enable, map); | |
193 | } | |
194 | ||
195 | static bool aspeed_sig_expr_enable(const struct aspeed_sig_expr *expr, | |
196 | struct regmap *map) | |
197 | { | |
5366f146 AJ |
198 | if (aspeed_sig_expr_eval(expr, true, map)) |
199 | return true; | |
200 | ||
4d3d0e42 AJ |
201 | return aspeed_sig_expr_set(expr, true, map); |
202 | } | |
203 | ||
204 | static bool aspeed_sig_expr_disable(const struct aspeed_sig_expr *expr, | |
205 | struct regmap *map) | |
206 | { | |
5366f146 AJ |
207 | if (!aspeed_sig_expr_eval(expr, true, map)) |
208 | return true; | |
209 | ||
4d3d0e42 AJ |
210 | return aspeed_sig_expr_set(expr, false, map); |
211 | } | |
212 | ||
213 | /** | |
214 | * Disable a signal on a pin by disabling all provided signal expressions. | |
215 | * | |
216 | * @exprs: The list of signal expressions (from a priority level on a pin) | |
217 | * @map: The SCU's regmap instance for pinmux register access. | |
218 | * | |
219 | * @return true if all expressions in the list are successfully disabled, false | |
220 | * otherwise | |
221 | */ | |
222 | static bool aspeed_disable_sig(const struct aspeed_sig_expr **exprs, | |
223 | struct regmap *map) | |
224 | { | |
225 | bool disabled = true; | |
226 | ||
227 | if (!exprs) | |
228 | return true; | |
229 | ||
230 | while (*exprs) { | |
231 | bool ret; | |
232 | ||
233 | ret = aspeed_sig_expr_disable(*exprs, map); | |
234 | disabled = disabled && ret; | |
235 | ||
236 | exprs++; | |
237 | } | |
238 | ||
239 | return disabled; | |
240 | } | |
241 | ||
242 | /** | |
243 | * Search for the signal expression needed to enable the pin's signal for the | |
244 | * requested function. | |
245 | * | |
246 | * @exprs: List of signal expressions (haystack) | |
247 | * @name: The name of the requested function (needle) | |
248 | * | |
249 | * @return A pointer to the signal expression whose function tag matches the | |
250 | * provided name, otherwise NULL. | |
251 | * | |
252 | */ | |
253 | static const struct aspeed_sig_expr *aspeed_find_expr_by_name( | |
254 | const struct aspeed_sig_expr **exprs, const char *name) | |
255 | { | |
256 | while (*exprs) { | |
257 | if (strcmp((*exprs)->function, name) == 0) | |
258 | return *exprs; | |
259 | exprs++; | |
260 | } | |
261 | ||
262 | return NULL; | |
263 | } | |
264 | ||
265 | static char *get_defined_attribute(const struct aspeed_pin_desc *pdesc, | |
266 | const char *(*get)( | |
267 | const struct aspeed_sig_expr *)) | |
268 | { | |
269 | char *found = NULL; | |
270 | size_t len = 0; | |
271 | const struct aspeed_sig_expr ***prios, **funcs, *expr; | |
272 | ||
273 | prios = pdesc->prios; | |
274 | ||
275 | while ((funcs = *prios)) { | |
276 | while ((expr = *funcs)) { | |
277 | const char *str = get(expr); | |
278 | size_t delta = strlen(str) + 2; | |
279 | char *expanded; | |
280 | ||
281 | expanded = krealloc(found, len + delta + 1, GFP_KERNEL); | |
282 | if (!expanded) { | |
283 | kfree(found); | |
284 | return expanded; | |
285 | } | |
286 | ||
287 | found = expanded; | |
288 | found[len] = '\0'; | |
289 | len += delta; | |
290 | ||
291 | strcat(found, str); | |
292 | strcat(found, ", "); | |
293 | ||
294 | funcs++; | |
295 | } | |
296 | prios++; | |
297 | } | |
298 | ||
299 | if (len < 2) { | |
300 | kfree(found); | |
301 | return NULL; | |
302 | } | |
303 | ||
304 | found[len - 2] = '\0'; | |
305 | ||
306 | return found; | |
307 | } | |
308 | ||
309 | static const char *aspeed_sig_expr_function(const struct aspeed_sig_expr *expr) | |
310 | { | |
311 | return expr->function; | |
312 | } | |
313 | ||
314 | static char *get_defined_functions(const struct aspeed_pin_desc *pdesc) | |
315 | { | |
316 | return get_defined_attribute(pdesc, aspeed_sig_expr_function); | |
317 | } | |
318 | ||
319 | static const char *aspeed_sig_expr_signal(const struct aspeed_sig_expr *expr) | |
320 | { | |
321 | return expr->signal; | |
322 | } | |
323 | ||
324 | static char *get_defined_signals(const struct aspeed_pin_desc *pdesc) | |
325 | { | |
326 | return get_defined_attribute(pdesc, aspeed_sig_expr_signal); | |
327 | } | |
328 | ||
329 | int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, | |
330 | unsigned int group) | |
331 | { | |
332 | int i; | |
333 | const struct aspeed_pinctrl_data *pdata = | |
334 | pinctrl_dev_get_drvdata(pctldev); | |
335 | const struct aspeed_pin_group *pgroup = &pdata->groups[group]; | |
336 | const struct aspeed_pin_function *pfunc = | |
337 | &pdata->functions[function]; | |
338 | ||
339 | for (i = 0; i < pgroup->npins; i++) { | |
340 | int pin = pgroup->pins[i]; | |
341 | const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data; | |
342 | const struct aspeed_sig_expr *expr = NULL; | |
343 | const struct aspeed_sig_expr **funcs; | |
344 | const struct aspeed_sig_expr ***prios; | |
345 | ||
346 | if (!pdesc) | |
347 | return -EINVAL; | |
348 | ||
349 | prios = pdesc->prios; | |
350 | ||
351 | if (!prios) | |
352 | continue; | |
353 | ||
354 | /* Disable functions at a higher priority than that requested */ | |
355 | while ((funcs = *prios)) { | |
356 | expr = aspeed_find_expr_by_name(funcs, pfunc->name); | |
357 | ||
358 | if (expr) | |
359 | break; | |
360 | ||
361 | if (!aspeed_disable_sig(funcs, pdata->map)) | |
362 | return -EPERM; | |
363 | ||
364 | prios++; | |
365 | } | |
366 | ||
367 | if (!expr) { | |
368 | char *functions = get_defined_functions(pdesc); | |
369 | char *signals = get_defined_signals(pdesc); | |
370 | ||
371 | pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n", | |
372 | pfunc->name, pdesc->name, pin, signals, | |
373 | functions); | |
374 | kfree(signals); | |
375 | kfree(functions); | |
376 | ||
377 | return -ENXIO; | |
378 | } | |
379 | ||
380 | if (!aspeed_sig_expr_enable(expr, pdata->map)) | |
381 | return -EPERM; | |
382 | } | |
383 | ||
384 | return 0; | |
385 | } | |
386 | ||
387 | static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr) | |
388 | { | |
389 | /* | |
390 | * The signal type is GPIO if the signal name has "GPIO" as a prefix. | |
391 | * strncmp (rather than strcmp) is used to implement the prefix | |
392 | * requirement. | |
393 | * | |
394 | * expr->signal might look like "GPIOT3" in the GPIO case. | |
395 | */ | |
396 | return strncmp(expr->signal, "GPIO", 4) == 0; | |
397 | } | |
398 | ||
399 | static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs) | |
400 | { | |
401 | if (!exprs) | |
402 | return false; | |
403 | ||
404 | while (*exprs) { | |
405 | if (aspeed_expr_is_gpio(*exprs)) | |
406 | return true; | |
407 | exprs++; | |
408 | } | |
409 | ||
410 | return false; | |
411 | } | |
412 | ||
413 | int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, | |
414 | struct pinctrl_gpio_range *range, | |
415 | unsigned int offset) | |
416 | { | |
417 | const struct aspeed_pinctrl_data *pdata = | |
418 | pinctrl_dev_get_drvdata(pctldev); | |
419 | const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data; | |
420 | const struct aspeed_sig_expr ***prios, **funcs, *expr; | |
421 | ||
422 | if (!pdesc) | |
423 | return -EINVAL; | |
424 | ||
425 | prios = pdesc->prios; | |
426 | ||
427 | if (!prios) | |
428 | return -ENXIO; | |
429 | ||
430 | /* Disable any functions of higher priority than GPIO */ | |
431 | while ((funcs = *prios)) { | |
432 | if (aspeed_gpio_in_exprs(funcs)) | |
433 | break; | |
434 | ||
435 | if (!aspeed_disable_sig(funcs, pdata->map)) | |
436 | return -EPERM; | |
437 | ||
438 | prios++; | |
439 | } | |
440 | ||
441 | if (!funcs) { | |
442 | char *signals = get_defined_signals(pdesc); | |
443 | ||
444 | pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n", | |
445 | pdesc->name, offset, signals); | |
446 | kfree(signals); | |
447 | ||
448 | return -ENXIO; | |
449 | } | |
450 | ||
451 | expr = *funcs; | |
452 | ||
453 | /* | |
454 | * Disabling all higher-priority expressions is enough to enable the | |
455 | * lowest-priority signal type. As such it has no associated | |
456 | * expression. | |
457 | */ | |
458 | if (!expr) | |
459 | return 0; | |
460 | ||
461 | /* | |
462 | * If GPIO is not the lowest priority signal type, assume there is only | |
463 | * one expression defined to enable the GPIO function | |
464 | */ | |
465 | if (!aspeed_sig_expr_enable(expr, pdata->map)) | |
466 | return -EPERM; | |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
471 | int aspeed_pinctrl_probe(struct platform_device *pdev, | |
472 | struct pinctrl_desc *pdesc, | |
473 | struct aspeed_pinctrl_data *pdata) | |
474 | { | |
475 | struct device *parent; | |
476 | struct pinctrl_dev *pctl; | |
477 | ||
478 | parent = pdev->dev.parent; | |
479 | if (!parent) { | |
480 | dev_err(&pdev->dev, "No parent for syscon pincontroller\n"); | |
481 | return -ENODEV; | |
482 | } | |
483 | ||
484 | pdata->map = syscon_node_to_regmap(parent->of_node); | |
485 | if (IS_ERR(pdata->map)) { | |
486 | dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n"); | |
487 | return PTR_ERR(pdata->map); | |
488 | } | |
489 | ||
490 | pctl = pinctrl_register(pdesc, &pdev->dev, pdata); | |
491 | ||
492 | if (IS_ERR(pctl)) { | |
493 | dev_err(&pdev->dev, "Failed to register pinctrl\n"); | |
494 | return PTR_ERR(pctl); | |
495 | } | |
496 | ||
497 | platform_set_drvdata(pdev, pdata); | |
498 | ||
499 | return 0; | |
500 | } |