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 #include <stdbool.h>
9 
10 /*
11  * The ASPEED SoCs provide typically more than 200 pins for GPIO and other
12  * functions. The SoC function enabled on a pin is determined on a priority
13  * basis where a given pin can provide a number of different signal types.
14  *
15  * The signal active on a pin is described by both a priority level and
16  * compound logical expressions involving multiple operators, registers and
17  * bits. Some difficulty arises as the pin's function bit masks for each
18  * priority level are frequently not the same (i.e. cannot just flip a bit to
19  * change from a high to low priority signal), or even in the same register.
20  * Further, not all signals can be unmuxed, as some expressions depend on
21  * values in the hardware strapping register (which may be treated as
22  * read-only).
23  *
24  * SoC Multi-function Pin Expression Examples
25  * ------------------------------------------
26  *
27  * Here are some sample mux configurations from the AST2400 and AST2500
28  * datasheets to illustrate the corner cases, roughly in order of least to most
29  * corner. The signal priorities are in decending order from P0 (highest).
30  *
31  * D6 is a pin with a single function (beside GPIO); a high priority signal
32  * that participates in one function:
33  *
34  * Ball | Default | P0 Signal | P0 Expression               | P1 Signal | P1 Expression | Other
35  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
36  *  D6    GPIOA0    MAC1LINK    SCU80[0]=1                                                GPIOA0
37  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
38  *
39  * C5 is a multi-signal pin (high and low priority signals). Here we touch
40  * different registers for the different functions that enable each signal:
41  *
42  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
43  *  C5    GPIOA4    SCL9        SCU90[22]=1                   TIMER5      SCU80[4]=1      GPIOA4
44  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
45  *
46  * E19 is a single-signal pin with two functions that influence the active
47  * signal. In this case both bits have the same meaning - enable a dedicated
48  * LPC reset pin. However it's not always the case that the bits in the
49  * OR-relationship have the same meaning.
50  *
51  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
52  *  E19   GPIOB4    LPCRST#     SCU80[12]=1 | Strap[14]=1                                 GPIOB4
53  * -----+---------+-----------+-----------------------------+-----------+---------------+----------
54  *
55  * For example, pin B19 has a low-priority signal that's enabled by two
56  * distinct SoC functions: A specific SIOPBI bit in register SCUA4, and an ACPI
57  * bit in the STRAP register. The ACPI bit configures signals on pins in
58  * addition to B19. Both of the low priority functions as well as the high
59  * priority function must be disabled for GPIOF1 to be used.
60  *
61  * Ball | Default | P0 Signal | P0 Expression                           | P1 Signal | P1 Expression                          | Other
62  * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
63  *  B19   GPIOF1    NDCD4       SCU80[25]=1                               SIOPBI#     SCUA4[12]=1 | Strap[19]=0                GPIOF1
64  * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
65  *
66  * For pin E18, the SoC ANDs the expected state of three bits to determine the
67  * pin's active signal:
68  *
69  * * SCU3C[3]: Enable external SOC reset function
70  * * SCU80[15]: Enable SPICS1# or EXTRST# function pin
71  * * SCU90[31]: Select SPI interface CS# output
72  *
73  * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
74  *  E18   GPIOB7    EXTRST#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=0    SPICS1#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=1   GPIOB7
75  * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
76  *
77  * (Bits SCU3C[3] and SCU80[15] appear to only be used in the expressions for
78  * selecting the signals on pin E18)
79  *
80  * Pin T5 is a multi-signal pin with a more complex configuration:
81  *
82  * Ball | Default | P0 Signal | P0 Expression                | P1 Signal | P1 Expression | Other
83  * -----+---------+-----------+------------------------------+-----------+---------------+----------
84  *  T5    GPIOL1    VPIDE       SCU90[5:4]!=0 & SCU84[17]=1    NDCD1       SCU84[17]=1     GPIOL1
85  * -----+---------+-----------+------------------------------+-----------+---------------+----------
86  *
87  * The high priority signal configuration is best thought of in terms of its
88  * exploded form, with reference to the SCU90[5:4] bits:
89  *
90  * * SCU90[5:4]=00: disable
91  * * SCU90[5:4]=01: 18 bits (R6/G6/B6) video mode.
92  * * SCU90[5:4]=10: 24 bits (R8/G8/B8) video mode.
93  * * SCU90[5:4]=11: 30 bits (R10/G10/B10) video mode.
94  *
95  * Re-writing:
96  *
97  * -----+---------+-----------+------------------------------+-----------+---------------+----------
98  *  T5    GPIOL1    VPIDE      (SCU90[5:4]=1 & SCU84[17]=1)    NDCD1       SCU84[17]=1     GPIOL1
99  *                             | (SCU90[5:4]=2 & SCU84[17]=1)
100  *                             | (SCU90[5:4]=3 & SCU84[17]=1)
101  * -----+---------+-----------+------------------------------+-----------+---------------+----------
102  *
103  * For reference the SCU84[17] bit configure the "UART1 NDCD1 or Video VPIDE
104  * function pin", where the signal itself is determined by whether SCU94[5:4]
105  * is disabled or in one of the 18, 24 or 30bit video modes.
106  *
107  * Other video-input-related pins require an explicit state in SCU90[5:4], e.g.
108  * W1 and U5:
109  *
110  * -----+---------+-----------+------------------------------+-----------+---------------+----------
111  *  W1    GPIOL6    VPIB0       SCU90[5:4]=3 & SCU84[22]=1     TXD1        SCU84[22]=1     GPIOL6
112  *  U5    GPIOL7    VPIB1       SCU90[5:4]=3 & SCU84[23]=1     RXD1        SCU84[23]=1     GPIOL7
113  * -----+---------+-----------+------------------------------+-----------+---------------+----------
114  *
115  * The examples of T5 and W1 are particularly fertile, as they also demonstrate
116  * that despite operating as part of the video input bus each signal needs to
117  * be enabled individually via it's own SCU84 (in the cases of T5 and W1)
118  * register bit. This is a little crazy if the bus doesn't have optional
119  * signals, but is used to decent effect with some of the UARTs where not all
120  * signals are required. However, this isn't done consistently - UART1 is
121  * enabled on a per-pin basis, and by contrast, all signals for UART6 are
122  * enabled by a single bit.
123  *
124  * Further, the high and low priority signals listed in the table above share
125  * a configuration bit. The VPI signals should operate in concert in a single
126  * function, but the UART signals should retain the ability to be configured
127  * independently. This pushes the implementation down the path of tagging a
128  * signal's expressions with the function they participate in, rather than
129  * defining masks affecting multiple signals per function. The latter approach
130  * fails in this instance where applying the configuration for the UART pin of
131  * interest will stomp on the state of other UART signals when disabling the
132  * VPI functions on the current pin.
133  *
134  * Ball |  Default   | P0 Signal | P0 Expression             | P1 Signal | P1 Expression | Other
135  * -----+------------+-----------+---------------------------+-----------+---------------+------------
136  *  A12   RGMII1TXCK   GPIOT0      SCUA0[0]=1                  RMII1TXEN   Strap[6]=0      RGMII1TXCK
137  *  B12   RGMII1TXCTL  GPIOT1      SCUA0[1]=1                  –           Strap[6]=0      RGMII1TXCTL
138  * -----+------------+-----------+---------------------------+-----------+---------------+------------
139  *
140  * A12 demonstrates that the "Other" signal isn't always GPIO - in this case
141  * GPIOT0 is a high-priority signal and RGMII1TXCK is Other. Thus, GPIO
142  * should be treated like any other signal type with full function expression
143  * requirements, and not assumed to be the default case. Separately, GPIOT0 and
144  * GPIOT1's signal descriptor bits are distinct, therefore we must iterate all
145  * pins in the function's group to disable the higher-priority signals such
146  * that the signal for the function of interest is correctly enabled.
147  *
148  * Finally, three priority levels aren't always enough; the AST2500 brings with
149  * it 18 pins of five priority levels, however the 18 pins only use three of
150  * the five priority levels.
151  *
152  * Ultimately the requirement to control pins in the examples above drive the
153  * design:
154  *
155  * * Pins provide signals according to functions activated in the mux
156  *   configuration
157  *
158  * * Pins provide up to five signal types in a priority order
159  *
160  * * For priorities levels defined on a pin, each priority provides one signal
161  *
162  * * Enabling lower priority signals requires higher priority signals be
163  *   disabled
164  *
165  * * A function represents a set of signals; functions are distinct if their
166  *   sets of signals are not equal
167  *
168  * * Signals participate in one or more functions
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   */
441 struct 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 string
455  *          "GPIO", e.g. GPIOA0, GPIOT4 etc.
456  * @function: The name of the function the signal participates in for the
457  *            associated expression
458  * @ndescs: The number of signal descriptors in the expression
459  * @descs: Pointer to an array of signal descriptors that comprise the
460  *         function expression
461  */
462 struct aspeed_sig_expr {
463 	const char *signal;
464 	const char *function;
465 	int ndescs;
466 	const struct aspeed_sig_desc *descs;
467 };
468 
469 /**
470  * A struct capturing the list of expressions enabling signals at each priority
471  * for a given pin. The signal configuration for a priority level is evaluated
472  * by ORing the evaluation of the signal expressions in the respective
473  * priority's list.
474  *
475  * @name: A name for the pin
476  * @prios: A pointer to an array of expression list pointers
477  *
478  */
479 struct aspeed_pin_desc {
480 	const char *name;
481 	const struct aspeed_sig_expr ***prios;
482 };
483 
484 /* Macro hell */
485 
486 #define SIG_DESC_IP_BIT(ip, reg, idx, val) \
487 	{ ip, reg, BIT_MASK(idx), val, (((val) + 1) & 1) }
488 
489 /**
490  * Short-hand macro for describing an SCU descriptor enabled by the state of
491  * one bit. The disable value is derived.
492  *
493  * @reg: The signal's associated register, offset from base
494  * @idx: The signal's bit index in the register
495  * @val: The value (0 or 1) that enables the function
496  */
497 #define SIG_DESC_BIT(reg, idx, val) \
498 	SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, val)
499 
500 #define SIG_DESC_IP_SET(ip, reg, idx) SIG_DESC_IP_BIT(ip, reg, idx, 1)
501 
502 /**
503  * A further short-hand macro expanding to an SCU descriptor enabled by a set
504  * bit.
505  *
506  * @reg: The register, offset from base
507  * @idx: The bit index in the register
508  */
509 #define SIG_DESC_SET(reg, idx) SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, 1)
510 
511 #define SIG_DESC_LIST_SYM(sig, func) sig_descs_ ## sig ## _ ## func
512 #define SIG_DESC_LIST_DECL(sig, func, ...) \
513 	static const struct aspeed_sig_desc SIG_DESC_LIST_SYM(sig, func)[] = \
514 		{ __VA_ARGS__ }
515 
516 #define SIG_EXPR_SYM(sig, func) sig_expr_ ## sig ## _ ## func
517 #define SIG_EXPR_DECL_(sig, func) \
518 	static const struct aspeed_sig_expr SIG_EXPR_SYM(sig, func) = \
519 	{ \
520 		.signal = #sig, \
521 		.function = #func, \
522 		.ndescs = ARRAY_SIZE(SIG_DESC_LIST_SYM(sig, func)), \
523 		.descs = &(SIG_DESC_LIST_SYM(sig, func))[0], \
524 	}
525 
526 /**
527  * Declare a signal expression.
528  *
529  * @sig: A macro symbol name for the signal (is subjected to stringification
530  *        and token pasting)
531  * @func: The function in which the signal is participating
532  * @...: Signal descriptors that define the signal expression
533  *
534  * For example, the following declares the ROMD8 signal for the ROM16 function:
535  *
536  *     SIG_EXPR_DECL(ROMD8, ROM16, SIG_DESC_SET(SCU90, 6));
537  *
538  * And with multiple signal descriptors:
539  *
540  *     SIG_EXPR_DECL(ROMD8, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
541  *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
542  */
543 #define SIG_EXPR_DECL(sig, func, ...) \
544 	SIG_DESC_LIST_DECL(sig, func, __VA_ARGS__); \
545 	SIG_EXPR_DECL_(sig, func)
546 
547 /**
548  * Declare a pointer to a signal expression
549  *
550  * @sig: The macro symbol name for the signal (subjected to token pasting)
551  * @func: The macro symbol name for the function (subjected to token pasting)
552  */
553 #define SIG_EXPR_PTR(sig, func) (&SIG_EXPR_SYM(sig, func))
554 
555 #define SIG_EXPR_LIST_SYM(sig) sig_exprs_ ## sig
556 
557 /**
558  * Declare a signal expression list for reference in a struct aspeed_pin_prio.
559  *
560  * @sig: A macro symbol name for the signal (is subjected to token pasting)
561  * @...: Signal expression structure pointers (use SIG_EXPR_PTR())
562  *
563  * For example, the 16-bit ROM bus can be enabled by one of two possible signal
564  * expressions:
565  *
566  *     SIG_EXPR_DECL(ROMD8, ROM16, SIG_DESC_SET(SCU90, 6));
567  *     SIG_EXPR_DECL(ROMD8, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
568  *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
569  *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
570  *              SIG_EXPR_PTR(ROMD8, ROM16S));
571  */
572 #define SIG_EXPR_LIST_DECL(sig, ...) \
573 	static const struct aspeed_sig_expr *SIG_EXPR_LIST_SYM(sig)[] = \
574 		{ __VA_ARGS__, NULL }
575 
576 /**
577  * A short-hand macro for declaring a function expression and an expression
578  * list with a single function.
579  *
580  * @func: A macro symbol name for the function (is subjected to token pasting)
581  * @...: Function descriptors that define the function expression
582  *
583  * For example, signal NCTS6 participates in its own function with one group:
584  *
585  *     SIG_EXPR_LIST_DECL_SINGLE(NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
586  */
587 #define SIG_EXPR_LIST_DECL_SINGLE(sig, func, ...) \
588 	SIG_DESC_LIST_DECL(sig, func, __VA_ARGS__); \
589 	SIG_EXPR_DECL_(sig, func); \
590 	SIG_EXPR_LIST_DECL(sig, SIG_EXPR_PTR(sig, func))
591 
592 #define SIG_EXPR_LIST_DECL_DUAL(sig, f0, f1) \
593 	SIG_EXPR_LIST_DECL(sig, SIG_EXPR_PTR(sig, f0), SIG_EXPR_PTR(sig, f1))
594 
595 #define SIG_EXPR_LIST_PTR(sig) (&SIG_EXPR_LIST_SYM(sig)[0])
596 
597 #define PIN_EXPRS_SYM(pin) pin_exprs_ ## pin
598 #define PIN_EXPRS_PTR(pin) (&PIN_EXPRS_SYM(pin)[0])
599 #define PIN_SYM(pin) pin_ ## pin
600 
601 #define MS_PIN_DECL_(pin, ...) \
602 	static const struct aspeed_sig_expr **PIN_EXPRS_SYM(pin)[] = \
603 		{ __VA_ARGS__, NULL }; \
604 	static const struct aspeed_pin_desc PIN_SYM(pin) = \
605 		{ #pin, PIN_EXPRS_PTR(pin) }
606 
607 /**
608  * Declare a multi-signal pin
609  *
610  * @pin: The pin number
611  * @other: Macro name for "other" functionality (subjected to stringification)
612  * @high: Macro name for the highest priority signal functions
613  * @low: Macro name for the low signal functions
614  *
615  * For example:
616  *
617  *     #define A8 56
618  *     SIG_EXPR_DECL(ROMD8, ROM16, SIG_DESC_SET(SCU90, 6));
619  *     SIG_EXPR_DECL(ROMD8, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
620  *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
621  *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
622  *              SIG_EXPR_PTR(ROMD8, ROM16S));
623  *     SIG_EXPR_LIST_DECL_SINGLE(NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
624  *     MS_PIN_DECL(A8, GPIOH0, ROMD8, NCTS6);
625  */
626 #define MS_PIN_DECL(pin, other, high, low) \
627 	SIG_EXPR_LIST_DECL_SINGLE(other, other); \
628 	MS_PIN_DECL_(pin, \
629 			SIG_EXPR_LIST_PTR(high), \
630 			SIG_EXPR_LIST_PTR(low), \
631 			SIG_EXPR_LIST_PTR(other))
632 
633 #define PIN_GROUP_SYM(func) pins_ ## func
634 #define FUNC_GROUP_SYM(func) groups_ ## func
635 #define FUNC_GROUP_DECL(func, ...) \
636 	static const int PIN_GROUP_SYM(func)[] = { __VA_ARGS__ }; \
637 	static const char *FUNC_GROUP_SYM(func)[] = { #func }
638 
639 /**
640  * Declare a single signal pin
641  *
642  * @pin: The pin number
643  * @other: Macro name for "other" functionality (subjected to stringification)
644  * @sig: Macro name for the signal (subjected to stringification)
645  *
646  * For example:
647  *
648  *     #define E3 80
649  *     SIG_EXPR_LIST_DECL_SINGLE(SCL5, I2C5, I2C5_DESC);
650  *     SS_PIN_DECL(E3, GPIOK0, SCL5);
651  */
652 #define SS_PIN_DECL(pin, other, sig) \
653 	SIG_EXPR_LIST_DECL_SINGLE(other, other); \
654 	MS_PIN_DECL_(pin, SIG_EXPR_LIST_PTR(sig), SIG_EXPR_LIST_PTR(other))
655 
656 /**
657  * Single signal, single function pin declaration
658  *
659  * @pin: The pin number
660  * @other: Macro name for "other" functionality (subjected to stringification)
661  * @sig: Macro name for the signal (subjected to stringification)
662  * @...: Signal descriptors that define the function expression
663  *
664  * For example:
665  *
666  *    SSSF_PIN_DECL(A4, GPIOA2, TIMER3, SIG_DESC_SET(SCU80, 2));
667  */
668 #define SSSF_PIN_DECL(pin, other, sig, ...) \
669 	SIG_EXPR_LIST_DECL_SINGLE(sig, sig, __VA_ARGS__); \
670 	SIG_EXPR_LIST_DECL_SINGLE(other, other); \
671 	MS_PIN_DECL_(pin, SIG_EXPR_LIST_PTR(sig), SIG_EXPR_LIST_PTR(other)); \
672 	FUNC_GROUP_DECL(sig, pin)
673 
674 #define GPIO_PIN_DECL(pin, gpio) \
675 	SIG_EXPR_LIST_DECL_SINGLE(gpio, gpio); \
676 	MS_PIN_DECL_(pin, SIG_EXPR_LIST_PTR(gpio))
677 
678 struct aspeed_pin_group {
679 	const char *name;
680 	const unsigned int *pins;
681 	const unsigned int npins;
682 };
683 
684 #define ASPEED_PINCTRL_GROUP(name_) { \
685 	.name = #name_, \
686 	.pins = &(PIN_GROUP_SYM(name_))[0], \
687 	.npins = ARRAY_SIZE(PIN_GROUP_SYM(name_)), \
688 }
689 
690 struct aspeed_pin_function {
691 	const char *name;
692 	const char *const *groups;
693 	unsigned int ngroups;
694 };
695 
696 #define ASPEED_PINCTRL_FUNC(name_, ...) { \
697 	.name = #name_, \
698 	.groups = &FUNC_GROUP_SYM(name_)[0], \
699 	.ngroups = ARRAY_SIZE(FUNC_GROUP_SYM(name_)), \
700 }
701 
702 struct aspeed_pinmux_data;
703 
704 struct aspeed_pinmux_ops {
705 	int (*set)(const struct aspeed_pinmux_data *ctx,
706 		   const struct aspeed_sig_expr *expr, bool enabled);
707 };
708 
709 struct aspeed_pinmux_data {
710 	struct regmap *maps[ASPEED_NR_PINMUX_IPS];
711 
712 	const struct aspeed_pinmux_ops *ops;
713 
714 	const struct aspeed_pin_group *groups;
715 	const unsigned int ngroups;
716 
717 	const struct aspeed_pin_function *functions;
718 	const unsigned int nfunctions;
719 };
720 
721 int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, bool enabled,
722 			 struct regmap *map);
723 
724 int aspeed_sig_expr_eval(const struct aspeed_pinmux_data *ctx,
725 			 const struct aspeed_sig_expr *expr,
726 			 bool enabled);
727 
728 static inline int aspeed_sig_expr_set(const struct aspeed_pinmux_data *ctx,
729 				      const struct aspeed_sig_expr *expr,
730 				      bool enabled)
731 {
732 	return ctx->ops->set(ctx, expr, enabled);
733 }
734 
735 #endif /* ASPEED_PINMUX_H */
736