1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2016 IBM Corp.
6 #include <linux/mfd/syscon.h>
7 #include <linux/platform_device.h>
8 #include <linux/slab.h>
9 #include <linux/string.h>
11 #include "pinctrl-aspeed.h"
13 int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
15 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
17 return pdata->pinmux.ngroups;
20 const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
23 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
25 return pdata->pinmux.groups[group].name;
28 int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
29 unsigned int group, const unsigned int **pins,
32 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
34 *pins = &pdata->pinmux.groups[group].pins[0];
35 *npins = pdata->pinmux.groups[group].npins;
40 void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
41 struct seq_file *s, unsigned int offset)
43 seq_printf(s, " %s", dev_name(pctldev->dev));
46 int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev)
48 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
50 return pdata->pinmux.nfunctions;
53 const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev,
54 unsigned int function)
56 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
58 return pdata->pinmux.functions[function].name;
61 int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev,
62 unsigned int function,
63 const char * const **groups,
64 unsigned int * const num_groups)
66 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
68 *groups = pdata->pinmux.functions[function].groups;
69 *num_groups = pdata->pinmux.functions[function].ngroups;
74 static int aspeed_sig_expr_enable(struct aspeed_pinmux_data *ctx,
75 const struct aspeed_sig_expr *expr)
79 pr_debug("Enabling signal %s for %s\n", expr->signal,
82 ret = aspeed_sig_expr_eval(ctx, expr, true);
87 return aspeed_sig_expr_set(ctx, expr, true);
92 static int aspeed_sig_expr_disable(struct aspeed_pinmux_data *ctx,
93 const struct aspeed_sig_expr *expr)
95 pr_debug("Disabling signal %s for %s\n", expr->signal,
98 return aspeed_sig_expr_set(ctx, expr, false);
102 * aspeed_disable_sig() - Disable a signal on a pin by disabling all provided
103 * signal expressions.
105 * @ctx: The pinmux context
106 * @exprs: The list of signal expressions (from a priority level on a pin)
108 * Return: 0 if all expressions are disabled, otherwise a negative error code
110 static int aspeed_disable_sig(struct aspeed_pinmux_data *ctx,
111 const struct aspeed_sig_expr **exprs)
118 while (*exprs && !ret) {
119 ret = aspeed_sig_expr_disable(ctx, *exprs);
127 * aspeed_find_expr_by_name - Search for the signal expression needed to
128 * enable the pin's signal for the requested function.
130 * @exprs: List of signal expressions (haystack)
131 * @name: The name of the requested function (needle)
133 * Return: A pointer to the signal expression whose function tag matches the
134 * provided name, otherwise NULL.
137 static const struct aspeed_sig_expr *aspeed_find_expr_by_name(
138 const struct aspeed_sig_expr **exprs, const char *name)
141 if (strcmp((*exprs)->function, name) == 0)
149 static char *get_defined_attribute(const struct aspeed_pin_desc *pdesc,
151 const struct aspeed_sig_expr *))
155 const struct aspeed_sig_expr ***prios, **funcs, *expr;
157 prios = pdesc->prios;
159 while ((funcs = *prios)) {
160 while ((expr = *funcs)) {
161 const char *str = get(expr);
162 size_t delta = strlen(str) + 2;
165 expanded = krealloc(found, len + delta + 1, GFP_KERNEL);
188 found[len - 2] = '\0';
193 static const char *aspeed_sig_expr_function(const struct aspeed_sig_expr *expr)
195 return expr->function;
198 static char *get_defined_functions(const struct aspeed_pin_desc *pdesc)
200 return get_defined_attribute(pdesc, aspeed_sig_expr_function);
203 static const char *aspeed_sig_expr_signal(const struct aspeed_sig_expr *expr)
208 static char *get_defined_signals(const struct aspeed_pin_desc *pdesc)
210 return get_defined_attribute(pdesc, aspeed_sig_expr_signal);
213 int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
218 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
219 const struct aspeed_pin_group *pgroup = &pdata->pinmux.groups[group];
220 const struct aspeed_pin_function *pfunc =
221 &pdata->pinmux.functions[function];
223 for (i = 0; i < pgroup->npins; i++) {
224 int pin = pgroup->pins[i];
225 const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data;
226 const struct aspeed_sig_expr *expr = NULL;
227 const struct aspeed_sig_expr **funcs;
228 const struct aspeed_sig_expr ***prios;
233 pr_debug("Muxing pin %s for %s\n", pdesc->name, pfunc->name);
235 prios = pdesc->prios;
240 /* Disable functions at a higher priority than that requested */
241 while ((funcs = *prios)) {
242 expr = aspeed_find_expr_by_name(funcs, pfunc->name);
247 ret = aspeed_disable_sig(&pdata->pinmux, funcs);
255 char *functions = get_defined_functions(pdesc);
256 char *signals = get_defined_signals(pdesc);
258 pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n",
259 pfunc->name, pdesc->name, pin, signals,
267 ret = aspeed_sig_expr_enable(&pdata->pinmux, expr);
271 pr_debug("Muxed pin %s as %s for %s\n", pdesc->name, expr->signal,
278 static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr)
281 * We need to differentiate between GPIO and non-GPIO signals to
282 * implement the gpio_request_enable() interface. For better or worse
283 * the ASPEED pinctrl driver uses the expression names to determine
284 * whether an expression will mux a pin for GPIO.
286 * Generally we have the following - A GPIO such as B1 has:
288 * - expr->signal set to "GPIOB1"
289 * - expr->function set to "GPIOB1"
291 * Using this fact we can determine whether the provided expression is
292 * a GPIO expression by testing the signal name for the string prefix
295 * However, some GPIOs are input-only, and the ASPEED datasheets name
296 * them differently. An input-only GPIO such as T0 has:
298 * - expr->signal set to "GPIT0"
299 * - expr->function set to "GPIT0"
301 * It's tempting to generalise the prefix test from "GPIO" to "GPI" to
302 * account for both GPIOs and GPIs, but in doing so we run aground on
305 * Some pins in the ASPEED BMC SoCs have a "pass-through" GPIO
306 * function where the input state of one pin is replicated as the
307 * output state of another (as if they were shorted together - a mux
308 * configuration that is typically enabled by hardware strapping).
309 * This feature allows the BMC to pass e.g. power button state through
310 * to the host while the BMC is yet to boot, but take control of the
311 * button state once the BMC has booted by muxing each pin as a
312 * separate, pin-specific GPIO.
314 * Conceptually this pass-through mode is a form of GPIO and is named
315 * as such in the datasheets, e.g. "GPID0". This naming similarity
316 * trips us up with the simple GPI-prefixed-signal-name scheme
317 * discussed above, as the pass-through configuration is not what we
318 * want when muxing a pin as GPIO for the GPIO subsystem.
320 * On e.g. the AST2400, a pass-through function "GPID0" is grouped on
321 * balls A18 and D16, where we have:
324 * - expr->signal set to "GPID0IN"
325 * - expr->function set to "GPID0"
328 * - expr->signal set to "GPID0OUT"
329 * - expr->function set to "GPID0"
331 * By contrast, the pin-specific GPIO expressions for the same pins are
335 * - expr->signal looks like "GPIOD0"
336 * - expr->function looks like "GPIOD0"
339 * - expr->signal looks like "GPIOD1"
340 * - expr->function looks like "GPIOD1"
342 * Testing both the signal _and_ function names gives us the means
343 * differentiate the pass-through GPIO pinmux configuration from the
344 * pin-specific configuration that the GPIO subsystem is after: An
345 * expression is a pin-specific (non-pass-through) GPIO configuration
346 * if the signal prefix is "GPI" and the signal name matches the
349 return !strncmp(expr->signal, "GPI", 3) &&
350 !strcmp(expr->signal, expr->function);
353 static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs)
359 if (aspeed_expr_is_gpio(*exprs))
367 int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev,
368 struct pinctrl_gpio_range *range,
372 struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
373 const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data;
374 const struct aspeed_sig_expr ***prios, **funcs, *expr;
379 prios = pdesc->prios;
384 pr_debug("Muxing pin %s for GPIO\n", pdesc->name);
386 /* Disable any functions of higher priority than GPIO */
387 while ((funcs = *prios)) {
388 if (aspeed_gpio_in_exprs(funcs))
391 ret = aspeed_disable_sig(&pdata->pinmux, funcs);
399 char *signals = get_defined_signals(pdesc);
401 pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n",
402 pdesc->name, offset, signals);
411 * Disabling all higher-priority expressions is enough to enable the
412 * lowest-priority signal type. As such it has no associated
416 pr_debug("Muxed pin %s as GPIO\n", pdesc->name);
421 * If GPIO is not the lowest priority signal type, assume there is only
422 * one expression defined to enable the GPIO function
424 ret = aspeed_sig_expr_enable(&pdata->pinmux, expr);
428 pr_debug("Muxed pin %s as %s\n", pdesc->name, expr->signal);
433 int aspeed_pinctrl_probe(struct platform_device *pdev,
434 struct pinctrl_desc *pdesc,
435 struct aspeed_pinctrl_data *pdata)
437 struct device *parent;
438 struct pinctrl_dev *pctl;
440 parent = pdev->dev.parent;
442 dev_err(&pdev->dev, "No parent for syscon pincontroller\n");
446 pdata->scu = syscon_node_to_regmap(parent->of_node);
447 if (IS_ERR(pdata->scu)) {
448 dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n");
449 return PTR_ERR(pdata->scu);
452 pdata->pinmux.maps[ASPEED_IP_SCU] = pdata->scu;
454 pctl = pinctrl_register(pdesc, &pdev->dev, pdata);
457 dev_err(&pdev->dev, "Failed to register pinctrl\n");
458 return PTR_ERR(pctl);
461 platform_set_drvdata(pdev, pdata);
466 static inline bool pin_in_config_range(unsigned int offset,
467 const struct aspeed_pin_config *config)
469 return offset >= config->pins[0] && offset <= config->pins[1];
472 static inline const struct aspeed_pin_config *find_pinconf_config(
473 const struct aspeed_pinctrl_data *pdata,
475 enum pin_config_param param)
479 for (i = 0; i < pdata->nconfigs; i++) {
480 if (param == pdata->configs[i].param &&
481 pin_in_config_range(offset, &pdata->configs[i]))
482 return &pdata->configs[i];
488 enum aspeed_pin_config_map_type { MAP_TYPE_ARG, MAP_TYPE_VAL };
490 static const struct aspeed_pin_config_map *find_pinconf_map(
491 const struct aspeed_pinctrl_data *pdata,
492 enum pin_config_param param,
493 enum aspeed_pin_config_map_type type,
498 for (i = 0; i < pdata->nconfmaps; i++) {
499 const struct aspeed_pin_config_map *elem;
502 elem = &pdata->confmaps[i];
506 match = (elem->arg == -1 || elem->arg == value);
509 match = (elem->val == value);
513 if (param == elem->param && match)
520 int aspeed_pin_config_get(struct pinctrl_dev *pctldev, unsigned int offset,
521 unsigned long *config)
523 const enum pin_config_param param = pinconf_to_config_param(*config);
524 const struct aspeed_pin_config_map *pmap;
525 const struct aspeed_pinctrl_data *pdata;
526 const struct aspeed_pin_config *pconf;
531 pdata = pinctrl_dev_get_drvdata(pctldev);
532 pconf = find_pinconf_config(pdata, offset, param);
536 rc = regmap_read(pdata->scu, pconf->reg, &val);
540 pmap = find_pinconf_map(pdata, param, MAP_TYPE_VAL,
541 (val & pconf->mask) >> __ffs(pconf->mask));
546 if (param == PIN_CONFIG_DRIVE_STRENGTH)
547 arg = (u32) pmap->arg;
548 else if (param == PIN_CONFIG_BIAS_PULL_DOWN)
556 *config = pinconf_to_config_packed(param, arg);
561 int aspeed_pin_config_set(struct pinctrl_dev *pctldev, unsigned int offset,
562 unsigned long *configs, unsigned int num_configs)
564 const struct aspeed_pinctrl_data *pdata;
568 pdata = pinctrl_dev_get_drvdata(pctldev);
570 for (i = 0; i < num_configs; i++) {
571 const struct aspeed_pin_config_map *pmap;
572 const struct aspeed_pin_config *pconf;
573 enum pin_config_param param;
577 param = pinconf_to_config_param(configs[i]);
578 arg = pinconf_to_config_argument(configs[i]);
580 pconf = find_pinconf_config(pdata, offset, param);
584 pmap = find_pinconf_map(pdata, param, MAP_TYPE_ARG, arg);
589 val = pmap->val << __ffs(pconf->mask);
591 rc = regmap_update_bits(pdata->scu, pconf->reg,
597 pr_debug("%s: Set SCU%02X[0x%08X]=0x%X for param %d(=%d) on pin %d\n",
598 __func__, pconf->reg, pconf->mask,
599 val, param, arg, offset);
605 int aspeed_pin_config_group_get(struct pinctrl_dev *pctldev,
606 unsigned int selector,
607 unsigned long *config)
609 const unsigned int *pins;
613 rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins);
620 rc = aspeed_pin_config_get(pctldev, pins[0], config);
625 int aspeed_pin_config_group_set(struct pinctrl_dev *pctldev,
626 unsigned int selector,
627 unsigned long *configs,
628 unsigned int num_configs)
630 const unsigned int *pins;
635 pr_debug("%s: Fetching pins for group selector %d\n",
637 rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins);
641 for (i = 0; i < npins; i++) {
642 rc = aspeed_pin_config_set(pctldev, pins[i], configs,