1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* Copyright (C) 2019 IBM Corp.  */
3
4#ifndef ASPEED_PINMUX_H
5#define ASPEED_PINMUX_H
6
7#include <linux/regmap.h>
8
9/*
10 * The ASPEED SoCs provide typically more than 200 pins for GPIO and other
11 * functions. The SoC function enabled on a pin is determined on a priority
12 * basis where a given pin can provide a number of different signal types.
13 *
14 * The signal active on a pin is described by both a priority level and
15 * compound logical expressions involving multiple operators, registers and
16 * bits. Some difficulty arises as the pin's function bit masks for each
17 * priority level are frequently not the same (i.e. cannot just flip a bit to
18 * change from a high to low priority signal), or even in the same register.
19 * Further, not all signals can be unmuxed, as some expressions depend on
20 * values in the hardware strapping register (which may be treated as
21 * read-only).
22 *
23 * SoC Multi-function Pin Expression Examples
24 * ------------------------------------------
25 *
26 * Here are some sample mux configurations from the AST2400 and AST2500
27 * datasheets to illustrate the corner cases, roughly in order of least to most
28 * corner. The signal priorities are in decending order from P0 (highest).
29 *
30 * D6 is a pin with a single function (beside GPIO); a high priority signal
31 * that participates in one function:
32 *
33 * Ball | Default | P0 Signal | P0 Expression               | P1 Signal | P1 Expression | Other
34 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
35 *  D6    GPIOA0    MAC1LINK    SCU80[0]=1                                                GPIOA0
36 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
37 *
38 * C5 is a multi-signal pin (high and low priority signals). Here we touch
39 * different registers for the different functions that enable each signal:
40 *
41 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
42 *  C5    GPIOA4    SCL9        SCU90[22]=1                   TIMER5      SCU80[4]=1      GPIOA4
43 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
44 *
45 * E19 is a single-signal pin with two functions that influence the active
46 * signal. In this case both bits have the same meaning - enable a dedicated
47 * LPC reset pin. However it's not always the case that the bits in the
48 * OR-relationship have the same meaning.
49 *
50 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
51 *  E19   GPIOB4    LPCRST#     SCU80[12]=1 | Strap[14]=1                                 GPIOB4
52 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
53 *
54 * For example, pin B19 has a low-priority signal that's enabled by two
55 * distinct SoC functions: A specific SIOPBI bit in register SCUA4, and an ACPI
56 * bit in the STRAP register. The ACPI bit configures signals on pins in
57 * addition to B19. Both of the low priority functions as well as the high
58 * priority function must be disabled for GPIOF1 to be used.
59 *
60 * Ball | Default | P0 Signal | P0 Expression                           | P1 Signal | P1 Expression                          | Other
61 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
62 *  B19   GPIOF1    NDCD4       SCU80[25]=1                               SIOPBI#     SCUA4[12]=1 | Strap[19]=0                GPIOF1
63 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
64 *
65 * For pin E18, the SoC ANDs the expected state of three bits to determine the
66 * pin's active signal:
67 *
68 * * SCU3C[3]: Enable external SOC reset function
69 * * SCU80[15]: Enable SPICS1# or EXTRST# function pin
70 * * SCU90[31]: Select SPI interface CS# output
71 *
72 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
73 *  E18   GPIOB7    EXTRST#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=0    SPICS1#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=1   GPIOB7
74 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
75 *
76 * (Bits SCU3C[3] and SCU80[15] appear to only be used in the expressions for
77 * selecting the signals on pin E18)
78 *
79 * Pin T5 is a multi-signal pin with a more complex configuration:
80 *
81 * Ball | Default | P0 Signal | P0 Expression                | P1 Signal | P1 Expression | Other
82 * -----+---------+-----------+------------------------------+-----------+---------------+----------
83 *  T5    GPIOL1    VPIDE       SCU90[5:4]!=0 & SCU84[17]=1    NDCD1       SCU84[17]=1     GPIOL1
84 * -----+---------+-----------+------------------------------+-----------+---------------+----------
85 *
86 * The high priority signal configuration is best thought of in terms of its
87 * exploded form, with reference to the SCU90[5:4] bits:
88 *
89 * * SCU90[5:4]=00: disable
90 * * SCU90[5:4]=01: 18 bits (R6/G6/B6) video mode.
91 * * SCU90[5:4]=10: 24 bits (R8/G8/B8) video mode.
92 * * SCU90[5:4]=11: 30 bits (R10/G10/B10) video mode.
93 *
94 * Re-writing:
95 *
96 * -----+---------+-----------+------------------------------+-----------+---------------+----------
97 *  T5    GPIOL1    VPIDE      (SCU90[5:4]=1 & SCU84[17]=1)    NDCD1       SCU84[17]=1     GPIOL1
98 *                             | (SCU90[5:4]=2 & SCU84[17]=1)
99 *                             | (SCU90[5:4]=3 & SCU84[17]=1)
100 * -----+---------+-----------+------------------------------+-----------+---------------+----------
101 *
102 * For reference the SCU84[17] bit configure the "UART1 NDCD1 or Video VPIDE
103 * function pin", where the signal itself is determined by whether SCU94[5:4]
104 * is disabled or in one of the 18, 24 or 30bit video modes.
105 *
106 * Other video-input-related pins require an explicit state in SCU90[5:4], e.g.
107 * W1 and U5:
108 *
109 * -----+---------+-----------+------------------------------+-----------+---------------+----------
110 *  W1    GPIOL6    VPIB0       SCU90[5:4]=3 & SCU84[22]=1     TXD1        SCU84[22]=1     GPIOL6
111 *  U5    GPIOL7    VPIB1       SCU90[5:4]=3 & SCU84[23]=1     RXD1        SCU84[23]=1     GPIOL7
112 * -----+---------+-----------+------------------------------+-----------+---------------+----------
113 *
114 * The examples of T5 and W1 are particularly fertile, as they also demonstrate
115 * that despite operating as part of the video input bus each signal needs to
116 * be enabled individually via it's own SCU84 (in the cases of T5 and W1)
117 * register bit. This is a little crazy if the bus doesn't have optional
118 * signals, but is used to decent effect with some of the UARTs where not all
119 * signals are required. However, this isn't done consistently - UART1 is
120 * enabled on a per-pin basis, and by contrast, all signals for UART6 are
121 * enabled by a single bit.
122 *
123 * Further, the high and low priority signals listed in the table above share
124 * a configuration bit. The VPI signals should operate in concert in a single
125 * function, but the UART signals should retain the ability to be configured
126 * independently. This pushes the implementation down the path of tagging a
127 * signal's expressions with the function they participate in, rather than
128 * defining masks affecting multiple signals per function. The latter approach
129 * fails in this instance where applying the configuration for the UART pin of
130 * interest will stomp on the state of other UART signals when disabling the
131 * VPI functions on the current pin.
132 *
133 * Ball |  Default   | P0 Signal | P0 Expression             | P1 Signal | P1 Expression | Other
134 * -----+------------+-----------+---------------------------+-----------+---------------+------------
135 *  A12   RGMII1TXCK   GPIOT0      SCUA0[0]=1                  RMII1TXEN   Strap[6]=0      RGMII1TXCK
136 *  B12   RGMII1TXCTL  GPIOT1      SCUA0[1]=1                  ���           Strap[6]=0      RGMII1TXCTL
137 * -----+------------+-----------+---------------------------+-----------+---------------+------------
138 *
139 * A12 demonstrates that the "Other" signal isn't always GPIO - in this case
140 * GPIOT0 is a high-priority signal and RGMII1TXCK is Other. Thus, GPIO
141 * should be treated like any other signal type with full function expression
142 * requirements, and not assumed to be the default case. Separately, GPIOT0 and
143 * GPIOT1's signal descriptor bits are distinct, therefore we must iterate all
144 * pins in the function's group to disable the higher-priority signals such
145 * that the signal for the function of interest is correctly enabled.
146 *
147 * Finally, three priority levels aren't always enough; the AST2500 brings with
148 * it 18 pins of five priority levels, however the 18 pins only use three of
149 * the five priority levels.
150 *
151 * Ultimately the requirement to control pins in the examples above drive the
152 * design:
153 *
154 * * Pins provide signals according to functions activated in the mux
155 *   configuration
156 *
157 * * Pins provide up to five signal types in a priority order
158 *
159 * * For priorities levels defined on a pin, each priority provides one signal
160 *
161 * * Enabling lower priority signals requires higher priority signals be
162 *   disabled
163 *
164 * * A function represents a set of signals; functions are distinct if they
165 *   do not share a subset of signals (and may be distinct if they are a
166 *   strict subset).
167 *
168 * * Signals participate in one or more functions or groups
169 *
170 * * A function is described by an expression of one or more signal
171 *   descriptors, which compare bit values in a register
172 *
173 * * A signal expression is the smallest set of signal descriptors whose
174 *   comparisons must evaluate 'true' for a signal to be enabled on a pin.
175 *
176 * * A signal participating in a function is active on a pin if evaluating all
177 *   signal descriptors in the pin's signal expression for the function yields
178 *   a 'true' result
179 *
180 * * A signal at a given priority on a given pin is active if any of the
181 *   functions in which the signal participates are active, and no higher
182 *   priority signal on the pin is active
183 *
184 * * GPIO is configured per-pin
185 *
186 * And so:
187 *
188 * * To disable a signal, any function(s) activating the signal must be
189 *   disabled
190 *
191 * * Each pin must know the signal expressions of functions in which it
192 *   participates, for the purpose of enabling the Other function. This is done
193 *   by deactivating all functions that activate higher priority signals on the
194 *   pin.
195 *
196 * As a concrete example:
197 *
198 * * T5 provides three signals types: VPIDE, NDCD1 and GPIO
199 *
200 * * The VPIDE signal participates in 3 functions: VPI18, VPI24 and VPI30
201 *
202 * * The NDCD1 signal participates in just its own NDCD1 function
203 *
204 * * VPIDE is high priority, NDCD1 is low priority, and GPIOL1 is the least
205 *   prioritised
206 *
207 * * The prerequisit for activating the NDCD1 signal is that the VPI18, VPI24
208 *   and VPI30 functions all be disabled
209 *
210 * * Similarly, all of VPI18, VPI24, VPI30 and NDCD1 functions must be disabled
211 *   to provide GPIOL6
212 *
213 * Considerations
214 * --------------
215 *
216 * If pinctrl allows us to allocate a pin we can configure a function without
217 * concern for the function of already allocated pins, if pin groups are
218 * created with respect to the SoC functions in which they participate. This is
219 * intuitive, but it did not feel obvious from the bit/pin relationships.
220 *
221 * Conversely, failing to allocate all pins in a group indicates some bits (as
222 * well as pins) required for the group's configuration will already be in use,
223 * likely in a way that's inconsistent with the requirements of the failed
224 * group.
225 *
226 * Implementation
227 * --------------
228 *
229 * Beyond the documentation below the various structures and helper macros that
230 * allow the implementation to hang together are defined. The macros are fairly
231 * dense, so below we walk through some raw examples of the configuration
232 * tables in an effort to clarify the concepts.
233 *
234 * The complexity of configuring the mux combined with the scale of the pins
235 * and functions was a concern, so the table design along with the macro jungle
236 * is an attempt to address it. The rough principles of the approach are:
237 *
238 * 1. Use a data-driven solution rather than embedding state into code
239 * 2. Minimise editing to the specifics of the given mux configuration
240 * 3. Detect as many errors as possible at compile time
241 *
242 * Addressing point 3 leads to naming of symbols in terms of the four
243 * properties associated with a given mux configuration: The pin, the signal,
244 * the group and the function. In this way copy/paste errors cause duplicate
245 * symbols to be defined, which prevents successful compilation. Failing to
246 * properly parent the tables leads to unused symbol warnings, and use of
247 * designated initialisers and additional warnings ensures that there are
248 * no override errors in the pin, group and function arrays.
249 *
250 * Addressing point 2 drives the development of the macro jungle, as it
251 * centralises the definition noise at the cost of taking some time to
252 * understand.
253 *
254 * Here's a complete, concrete "pre-processed" example of the table structures
255 * used to describe the D6 ball from the examples above:
256 *
257 * ```
258 * static const struct aspeed_sig_desc sig_descs_MAC1LINK_MAC1LINK[] = {
259 *     {
260 *         .ip = ASPEED_IP_SCU,
261 *         .reg = 0x80,
262 *         .mask = BIT(0),
263 *         .enable = 1,
264 *         .disable = 0
265 *     },
266 * };
267 *
268 * static const struct aspeed_sig_expr sig_expr_MAC1LINK_MAC1LINK = {
269 *     .signal = "MAC1LINK",
270 *     .function = "MAC1LINK",
271 *     .ndescs = ARRAY_SIZE(sig_descs_MAC1LINK_MAC1LINK),
272 *     .descs = &(sig_descs_MAC1LINK_MAC1LINK)[0],
273 * };
274 *
275 * static const struct aspeed_sig_expr *sig_exprs_MAC1LINK_MAC1LINK[] = {
276 *     &sig_expr_MAC1LINK_MAC1LINK,
277 *     NULL,
278 * };
279 *
280 * static const struct aspeed_sig_desc sig_descs_GPIOA0_GPIOA0[] = { };
281 *
282 * static const struct aspeed_sig_expr sig_expr_GPIOA0_GPIOA0 = {
283 *     .signal = "GPIOA0",
284 *     .function = "GPIOA0",
285 *     .ndescs = ARRAY_SIZE(sig_descs_GPIOA0_GPIOA0),
286 *     .descs = &(sig_descs_GPIOA0_GPIOA0)[0],
287 * };
288 *
289 * static const struct aspeed_sig_expr *sig_exprs_GPIOA0_GPIOA0[] = {
290 *     &sig_expr_GPIOA0_GPIOA0,
291 *     NULL
292 * };
293 *
294 * static const struct aspeed_sig_expr **pin_exprs_0[] = {
295 *     sig_exprs_MAC1LINK_MAC1LINK,
296 *     sig_exprs_GPIOA0_GPIOA0,
297 *     NULL
298 * };
299 *
300 * static const struct aspeed_pin_desc pin_0 = { "0", (&pin_exprs_0[0]) };
301 * static const int group_pins_MAC1LINK[] = { 0 };
302 * static const char *func_groups_MAC1LINK[] = { "MAC1LINK" };
303 *
304 * static struct pinctrl_pin_desc aspeed_g4_pins[] = {
305 *     [0] = { .number = 0, .name = "D6", .drv_data = &pin_0 },
306 * };
307 *
308 * static const struct aspeed_pin_group aspeed_g4_groups[] = {
309 *     {
310 *         .name = "MAC1LINK",
311 *         .pins = &(group_pins_MAC1LINK)[0],
312 *         .npins = ARRAY_SIZE(group_pins_MAC1LINK),
313 *     },
314 * };
315 *
316 * static const struct aspeed_pin_function aspeed_g4_functions[] = {
317 *     {
318 *         .name = "MAC1LINK",
319 *         .groups = &func_groups_MAC1LINK[0],
320 *         .ngroups = ARRAY_SIZE(func_groups_MAC1LINK),
321 *     },
322 * };
323 * ```
324 *
325 * At the end of the day much of the above code is compressed into the
326 * following two lines:
327 *
328 * ```
329 * #define D6 0
330 * SSSF_PIN_DECL(D6, GPIOA0, MAC1LINK, SIG_DESC_SET(SCU80, 0));
331 * ```
332 *
333 * The two examples below show just the differences from the example above.
334 *
335 * Ball E18 demonstrates a function, EXTRST, that requires multiple descriptors
336 * be set for it to be muxed:
337 *
338 * ```
339 * static const struct aspeed_sig_desc sig_descs_EXTRST_EXTRST[] = {
340 *     {
341 *         .ip = ASPEED_IP_SCU,
342 *         .reg = 0x3C,
343 *         .mask = BIT(3),
344 *         .enable = 1,
345 *         .disable = 0
346 *     },
347 *     {
348 *         .ip = ASPEED_IP_SCU,
349 *         .reg = 0x80,
350 *         .mask = BIT(15),
351 *         .enable = 1,
352 *         .disable = 0
353 *     },
354 *     {
355 *         .ip = ASPEED_IP_SCU,
356 *         .reg = 0x90,
357 *         .mask = BIT(31),
358 *         .enable = 0,
359 *         .disable = 1
360 *     },
361 * };
362 *
363 * static const struct aspeed_sig_expr sig_expr_EXTRST_EXTRST = {
364 *     .signal = "EXTRST",
365 *     .function = "EXTRST",
366 *     .ndescs = ARRAY_SIZE(sig_descs_EXTRST_EXTRST),
367 *     .descs = &(sig_descs_EXTRST_EXTRST)[0],
368 * };
369 * ...
370 * ```
371 *
372 * For ball E19, we have multiple functions enabling a single signal, LPCRST#.
373 * The data structures look like:
374 *
375 * static const struct aspeed_sig_desc sig_descs_LPCRST_LPCRST[] = {
376 *     {
377 *         .ip = ASPEED_IP_SCU,
378 *         .reg = 0x80,
379 *         .mask = BIT(12),
380 *         .enable = 1,
381 *         .disable = 0
382 *     },
383 * };
384 *
385 * static const struct aspeed_sig_expr sig_expr_LPCRST_LPCRST = {
386 *     .signal = "LPCRST",
387 *     .function = "LPCRST",
388 *     .ndescs = ARRAY_SIZE(sig_descs_LPCRST_LPCRST),
389 *     .descs = &(sig_descs_LPCRST_LPCRST)[0],
390 * };
391 *
392 * static const struct aspeed_sig_desc sig_descs_LPCRST_LPCRSTS[] = {
393 *     {
394 *         .ip = ASPEED_IP_SCU,
395 *         .reg = 0x70,
396 *         .mask = BIT(14),
397 *         .enable = 1,
398 *         .disable = 0
399 *     },
400 * };
401 *
402 * static const struct aspeed_sig_expr sig_expr_LPCRST_LPCRSTS = {
403 *     .signal = "LPCRST",
404 *     .function = "LPCRSTS",
405 *     .ndescs = ARRAY_SIZE(sig_descs_LPCRST_LPCRSTS),
406 *     .descs = &(sig_descs_LPCRST_LPCRSTS)[0],
407 * };
408 *
409 * static const struct aspeed_sig_expr *sig_exprs_LPCRST_LPCRST[] = {
410 *     &sig_expr_LPCRST_LPCRST,
411 *     &sig_expr_LPCRST_LPCRSTS,
412 *     NULL,
413 * };
414 * ...
415 * ```
416 *
417 * Both expressions listed in the sig_exprs_LPCRST_LPCRST array need to be set
418 * to disabled for the associated GPIO to be muxed.
419 *
420 */
421
422#define ASPEED_IP_SCU		0
423#define ASPEED_IP_GFX		1
424#define ASPEED_IP_LPC		2
425#define ASPEED_NR_PINMUX_IPS	3
426
427 /**
428  * A signal descriptor, which describes the register, bits and the
429  * enable/disable values that should be compared or written.
430  *
431  * @ip: The IP block identifier, used as an index into the regmap array in
432  *      struct aspeed_pinctrl_data
433  * @reg: The register offset with respect to the base address of the IP block
434  * @mask: The mask to apply to the register. The lowest set bit of the mask is
435  *        used to derive the shift value.
436  * @enable: The value that enables the function. Value should be in the LSBs,
437  *          not at the position of the mask.
438  * @disable: The value that disables the function. Value should be in the
439  *           LSBs, not at the position of the mask.
440  */
441struct aspeed_sig_desc {
442	unsigned int ip;
443	unsigned int reg;
444	u32 mask;
445	u32 enable;
446	u32 disable;
447};
448
449/**
450 * Describes a signal expression. The expression is evaluated by ANDing the
451 * evaluation of the descriptors.
452 *
453 * @signal: The signal name for the priority level on the pin. If the signal
454 *          type is GPIO, then the signal name must begin with the
455 *          prefix "GPI", e.g. GPIOA0, GPIT0 etc.
456 * @function: The name of the function the signal participates in for the
457 *            associated expression. For pin-specific GPIO, the function
458 *            name must match the signal name.
459 * @ndescs: The number of signal descriptors in the expression
460 * @descs: Pointer to an array of signal descriptors that comprise the
461 *         function expression
462 */
463struct aspeed_sig_expr {
464	const char *signal;
465	const char *function;
466	int ndescs;
467	const struct aspeed_sig_desc *descs;
468};
469
470/**
471 * A struct capturing the list of expressions enabling signals at each priority
472 * for a given pin. The signal configuration for a priority level is evaluated
473 * by ORing the evaluation of the signal expressions in the respective
474 * priority's list.
475 *
476 * @name: A name for the pin
477 * @prios: A pointer to an array of expression list pointers
478 *
479 */
480struct aspeed_pin_desc {
481	const char *name;
482	const struct aspeed_sig_expr ***prios;
483};
484
485/* Macro hell */
486
487#define SIG_DESC_IP_BIT(ip, reg, idx, val) \
488	{ ip, reg, BIT_MASK(idx), val, (((val) + 1) & 1) }
489
490/**
491 * Short-hand macro for describing an SCU descriptor enabled by the state of
492 * one bit. The disable value is derived.
493 *
494 * @reg: The signal's associated register, offset from base
495 * @idx: The signal's bit index in the register
496 * @val: The value (0 or 1) that enables the function
497 */
498#define SIG_DESC_BIT(reg, idx, val) \
499	SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, val)
500
501#define SIG_DESC_IP_SET(ip, reg, idx) SIG_DESC_IP_BIT(ip, reg, idx, 1)
502
503/**
504 * A further short-hand macro expanding to an SCU descriptor enabled by a set
505 * bit.
506 *
507 * @reg: The register, offset from base
508 * @idx: The bit index in the register
509 */
510#define SIG_DESC_SET(reg, idx) SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, 1)
511#define SIG_DESC_CLEAR(reg, idx) { ASPEED_IP_SCU, reg, BIT_MASK(idx), 0, 0 }
512
513#define SIG_DESC_LIST_SYM(sig, group) sig_descs_ ## sig ## _ ## group
514#define SIG_DESC_LIST_DECL(sig, group, ...) \
515	static const struct aspeed_sig_desc SIG_DESC_LIST_SYM(sig, group)[] = \
516		{ __VA_ARGS__ }
517
518#define SIG_EXPR_SYM(sig, group) sig_expr_ ## sig ## _ ## group
519#define SIG_EXPR_DECL_(sig, group, func) \
520	static const struct aspeed_sig_expr SIG_EXPR_SYM(sig, group) = \
521	{ \
522		.signal = #sig, \
523		.function = #func, \
524		.ndescs = ARRAY_SIZE(SIG_DESC_LIST_SYM(sig, group)), \
525		.descs = &(SIG_DESC_LIST_SYM(sig, group))[0], \
526	}
527
528/**
529 * Declare a signal expression.
530 *
531 * @sig: A macro symbol name for the signal (is subjected to stringification
532 *        and token pasting)
533 * @func: The function in which the signal is participating
534 * @...: Signal descriptors that define the signal expression
535 *
536 * For example, the following declares the ROMD8 signal for the ROM16 function:
537 *
538 *     SIG_EXPR_DECL(ROMD8, ROM16, ROM16, SIG_DESC_SET(SCU90, 6));
539 *
540 * And with multiple signal descriptors:
541 *
542 *     SIG_EXPR_DECL(ROMD8, ROM16S, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
543 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
544 */
545#define SIG_EXPR_DECL(sig, group, func, ...) \
546	SIG_DESC_LIST_DECL(sig, group, __VA_ARGS__); \
547	SIG_EXPR_DECL_(sig, group, func)
548
549/**
550 * Declare a pointer to a signal expression
551 *
552 * @sig: The macro symbol name for the signal (subjected to token pasting)
553 * @func: The macro symbol name for the function (subjected to token pasting)
554 */
555#define SIG_EXPR_PTR(sig, group) (&SIG_EXPR_SYM(sig, group))
556
557#define SIG_EXPR_LIST_SYM(sig, group) sig_exprs_ ## sig ## _ ## group
558
559/**
560 * Declare a signal expression list for reference in a struct aspeed_pin_prio.
561 *
562 * @sig: A macro symbol name for the signal (is subjected to token pasting)
563 * @...: Signal expression structure pointers (use SIG_EXPR_PTR())
564 *
565 * For example, the 16-bit ROM bus can be enabled by one of two possible signal
566 * expressions:
567 *
568 *     SIG_EXPR_DECL(ROMD8, ROM16, ROM16, SIG_DESC_SET(SCU90, 6));
569 *     SIG_EXPR_DECL(ROMD8, ROM16S, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
570 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
571 *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
572 *              SIG_EXPR_PTR(ROMD8, ROM16S));
573 */
574#define SIG_EXPR_LIST_DECL(sig, group, ...) \
575	static const struct aspeed_sig_expr *SIG_EXPR_LIST_SYM(sig, group)[] =\
576		{ __VA_ARGS__, NULL }
577
578#define stringify(x) #x
579#define istringify(x) stringify(x)
580
581/**
582 * Create an expression symbol alias from (signal, group) to (pin, signal).
583 *
584 * @pin: The pin number
585 * @sig: The signal name
586 * @group: The name of the group of which the pin is a member that is
587 *         associated with the function's signal
588 *
589 * Using an alias in this way enables detection of copy/paste errors (defining
590 * the signal for a group multiple times) whilst enabling multiple pin groups
591 * to exist for a signal without intrusive side-effects on defining the list of
592 * signals available on a pin.
593 */
594#define SIG_EXPR_LIST_ALIAS(pin, sig, group) \
595	static const struct aspeed_sig_expr *\
596		SIG_EXPR_LIST_SYM(pin, sig)[ARRAY_SIZE(SIG_EXPR_LIST_SYM(sig, group))] \
597		__attribute__((alias(istringify(SIG_EXPR_LIST_SYM(sig, group)))))
598
599/**
600 * A short-hand macro for declaring a function expression and an expression
601 * list with a single expression (SE) and a single group (SG) of pins.
602 *
603 * @pin: The pin the signal will be routed to
604 * @sig: The signal that will be routed to the pin for the function
605 * @func: A macro symbol name for the function
606 * @...: Function descriptors that define the function expression
607 *
608 * For example, signal NCTS6 participates in its own function with one group:
609 *
610 *     SIG_EXPR_LIST_DECL_SINGLE(A18, NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
611 */
612#define SIG_EXPR_LIST_DECL_SESG(pin, sig, func, ...) \
613	SIG_DESC_LIST_DECL(sig, func, __VA_ARGS__); \
614	SIG_EXPR_DECL_(sig, func, func); \
615	SIG_EXPR_LIST_DECL(sig, func, SIG_EXPR_PTR(sig, func)); \
616	SIG_EXPR_LIST_ALIAS(pin, sig, func)
617
618/**
619 * Similar to the above, but for pins with a single expression (SE) and
620 * multiple groups (MG) of pins.
621 *
622 * @pin: The pin the signal will be routed to
623 * @sig: The signal that will be routed to the pin for the function
624 * @group: The name of the function's pin group in which the pin participates
625 * @func: A macro symbol name for the function
626 * @...: Function descriptors that define the function expression
627 */
628#define SIG_EXPR_LIST_DECL_SEMG(pin, sig, group, func, ...) \
629	SIG_DESC_LIST_DECL(sig, group, __VA_ARGS__); \
630	SIG_EXPR_DECL_(sig, group, func); \
631	SIG_EXPR_LIST_DECL(sig, group, SIG_EXPR_PTR(sig, group)); \
632	SIG_EXPR_LIST_ALIAS(pin, sig, group)
633
634/**
635 * Similar to the above, but for pins with a dual expressions (DE)
636 * and a single group (SG) of pins.
637 *
638 * @pin: The pin the signal will be routed to
639 * @sig: The signal that will be routed to the pin for the function
640 * @group: The name of the function's pin group in which the pin participates
641 * @func: A macro symbol name for the function
642 * @...: Function descriptors that define the function expression
643 */
644#define SIG_EXPR_LIST_DECL_DESG(pin, sig, f0, f1) \
645	SIG_EXPR_LIST_DECL(sig, f0, \
646			   SIG_EXPR_PTR(sig, f0), \
647			   SIG_EXPR_PTR(sig, f1)); \
648	SIG_EXPR_LIST_ALIAS(pin, sig, f0)
649
650#define SIG_EXPR_LIST_PTR(sig, group) SIG_EXPR_LIST_SYM(sig, group)
651
652#define PIN_EXPRS_SYM(pin) pin_exprs_ ## pin
653#define PIN_EXPRS_PTR(pin) (&PIN_EXPRS_SYM(pin)[0])
654#define PIN_SYM(pin) pin_ ## pin
655
656#define PIN_DECL_(pin, ...) \
657	static const struct aspeed_sig_expr **PIN_EXPRS_SYM(pin)[] = \
658		{ __VA_ARGS__, NULL }; \
659	static const struct aspeed_pin_desc PIN_SYM(pin) = \
660		{ #pin, PIN_EXPRS_PTR(pin) }
661
662/**
663 * Declare a single signal pin
664 *
665 * @pin: The pin number
666 * @other: Macro name for "other" functionality (subjected to stringification)
667 * @sig: Macro name for the signal (subjected to stringification)
668 *
669 * For example:
670 *
671 *     #define E3 80
672 *     SIG_EXPR_LIST_DECL_SINGLE(SCL5, I2C5, I2C5_DESC);
673 *     PIN_DECL_1(E3, GPIOK0, SCL5);
674 */
675#define PIN_DECL_1(pin, other, sig) \
676	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
677	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, sig), \
678		  SIG_EXPR_LIST_PTR(pin, other))
679
680/**
681 * Single signal, single function pin declaration
682 *
683 * @pin: The pin number
684 * @other: Macro name for "other" functionality (subjected to stringification)
685 * @sig: Macro name for the signal (subjected to stringification)
686 * @...: Signal descriptors that define the function expression
687 *
688 * For example:
689 *
690 *    SSSF_PIN_DECL(A4, GPIOA2, TIMER3, SIG_DESC_SET(SCU80, 2));
691 */
692#define SSSF_PIN_DECL(pin, other, sig, ...) \
693	SIG_EXPR_LIST_DECL_SESG(pin, sig, sig, __VA_ARGS__); \
694	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
695	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, sig), \
696		  SIG_EXPR_LIST_PTR(pin, other)); \
697	FUNC_GROUP_DECL(sig, pin)
698/**
699 * Declare a two-signal pin
700 *
701 * @pin: The pin number
702 * @other: Macro name for "other" functionality (subjected to stringification)
703 * @high: Macro name for the highest priority signal functions
704 * @low: Macro name for the low signal functions
705 *
706 * For example:
707 *
708 *     #define A8 56
709 *     SIG_EXPR_DECL(ROMD8, ROM16, SIG_DESC_SET(SCU90, 6));
710 *     SIG_EXPR_DECL(ROMD8, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
711 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
712 *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
713 *              SIG_EXPR_PTR(ROMD8, ROM16S));
714 *     SIG_EXPR_LIST_DECL_SINGLE(NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
715 *     PIN_DECL_2(A8, GPIOH0, ROMD8, NCTS6);
716 */
717#define PIN_DECL_2(pin, other, high, low) \
718	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
719	PIN_DECL_(pin, \
720			SIG_EXPR_LIST_PTR(pin, high), \
721			SIG_EXPR_LIST_PTR(pin, low), \
722			SIG_EXPR_LIST_PTR(pin, other))
723
724#define PIN_DECL_3(pin, other, high, medium, low) \
725	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
726	PIN_DECL_(pin, \
727			SIG_EXPR_LIST_PTR(pin, high), \
728			SIG_EXPR_LIST_PTR(pin, medium), \
729			SIG_EXPR_LIST_PTR(pin, low), \
730			SIG_EXPR_LIST_PTR(pin, other))
731
732#define PIN_DECL_4(pin, other, prio1, prio2, prio3, prio4) \
733	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
734	PIN_DECL_(pin, \
735			SIG_EXPR_LIST_PTR(pin, prio1), \
736			SIG_EXPR_LIST_PTR(pin, prio2), \
737			SIG_EXPR_LIST_PTR(pin, prio3), \
738			SIG_EXPR_LIST_PTR(pin, prio4), \
739			SIG_EXPR_LIST_PTR(pin, other))
740
741#define GROUP_SYM(group) group_pins_ ## group
742#define GROUP_DECL(group, ...) \
743	static const int GROUP_SYM(group)[] = { __VA_ARGS__ }
744
745#define FUNC_SYM(func) func_groups_ ## func
746#define FUNC_DECL_(func, ...) \
747	static const char *FUNC_SYM(func)[] = { __VA_ARGS__ }
748
749#define FUNC_DECL_1(func, group) FUNC_DECL_(func, #group)
750#define FUNC_DECL_2(func, one, two) FUNC_DECL_(func, #one, #two)
751#define FUNC_DECL_3(func, one, two, three) FUNC_DECL_(func, #one, #two, #three)
752
753#define FUNC_GROUP_DECL(func, ...) \
754	GROUP_DECL(func, __VA_ARGS__); \
755	FUNC_DECL_(func, #func)
756
757
758#define GPIO_PIN_DECL(pin, gpio) \
759	SIG_EXPR_LIST_DECL_SESG(pin, gpio, gpio); \
760	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, gpio))
761
762struct aspeed_pin_group {
763	const char *name;
764	const unsigned int *pins;
765	const unsigned int npins;
766};
767
768#define ASPEED_PINCTRL_GROUP(name_) { \
769	.name = #name_, \
770	.pins = &(GROUP_SYM(name_))[0], \
771	.npins = ARRAY_SIZE(GROUP_SYM(name_)), \
772}
773
774struct aspeed_pin_function {
775	const char *name;
776	const char *const *groups;
777	unsigned int ngroups;
778};
779
780#define ASPEED_PINCTRL_FUNC(name_, ...) { \
781	.name = #name_, \
782	.groups = &FUNC_SYM(name_)[0], \
783	.ngroups = ARRAY_SIZE(FUNC_SYM(name_)), \
784}
785
786struct aspeed_pinmux_data;
787
788struct aspeed_pinmux_ops {
789	int (*eval)(struct aspeed_pinmux_data *ctx,
790		    const struct aspeed_sig_expr *expr, bool enabled);
791	int (*set)(struct aspeed_pinmux_data *ctx,
792		   const struct aspeed_sig_expr *expr, bool enabled);
793};
794
795struct aspeed_pinmux_data {
796	struct device *dev;
797	struct regmap *maps[ASPEED_NR_PINMUX_IPS];
798
799	const struct aspeed_pinmux_ops *ops;
800
801	const struct aspeed_pin_group *groups;
802	const unsigned int ngroups;
803
804	const struct aspeed_pin_function *functions;
805	const unsigned int nfunctions;
806};
807
808int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, bool enabled,
809			 struct regmap *map);
810
811int aspeed_sig_expr_eval(struct aspeed_pinmux_data *ctx,
812			 const struct aspeed_sig_expr *expr, bool enabled);
813
814static inline int aspeed_sig_expr_set(struct aspeed_pinmux_data *ctx,
815				      const struct aspeed_sig_expr *expr,
816				      bool enabled)
817{
818	return ctx->ops->set(ctx, expr, enabled);
819}
820
821#endif /* ASPEED_PINMUX_H */
822