diff options
Diffstat (limited to 'drivers/pinctrl/aspeed/pinctrl-aspeed.c')
| -rw-r--r-- | drivers/pinctrl/aspeed/pinctrl-aspeed.c | 406 |
1 files changed, 142 insertions, 264 deletions
diff --git a/drivers/pinctrl/aspeed/pinctrl-aspeed.c b/drivers/pinctrl/aspeed/pinctrl-aspeed.c index eb87ab774269..7e0ebf11af16 100644 --- a/drivers/pinctrl/aspeed/pinctrl-aspeed.c +++ b/drivers/pinctrl/aspeed/pinctrl-aspeed.c @@ -1,30 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (C) 2016 IBM Corp. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. */ #include <linux/mfd/syscon.h> #include <linux/platform_device.h> +#include <linux/seq_file.h> #include <linux/slab.h> #include <linux/string.h> #include "../core.h" #include "pinctrl-aspeed.h" -static const char *const aspeed_pinmux_ips[] = { - [ASPEED_IP_SCU] = "SCU", - [ASPEED_IP_GFX] = "GFX", - [ASPEED_IP_LPC] = "LPC", -}; - int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - return pdata->ngroups; + return pdata->pinmux.ngroups; } const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev, @@ -32,7 +23,7 @@ const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev, { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - return pdata->groups[group].name; + return pdata->pinmux.groups[group].name; } int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, @@ -41,8 +32,8 @@ int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - *pins = &pdata->groups[group].pins[0]; - *npins = pdata->groups[group].npins; + *pins = &pdata->pinmux.groups[group].pins[0]; + *npins = pdata->pinmux.groups[group].npins; return 0; } @@ -57,7 +48,7 @@ int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev) { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - return pdata->nfunctions; + return pdata->pinmux.nfunctions; } const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev, @@ -65,7 +56,7 @@ const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev, { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - return pdata->functions[function].name; + return pdata->pinmux.functions[function].name; } int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev, @@ -75,230 +66,67 @@ int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev, { struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); - *groups = pdata->functions[function].groups; - *num_groups = pdata->functions[function].ngroups; + *groups = pdata->pinmux.functions[function].groups; + *num_groups = pdata->pinmux.functions[function].ngroups; return 0; } -static inline void aspeed_sig_desc_print_val( - const struct aspeed_sig_desc *desc, bool enable, u32 rv) -{ - pr_debug("Want %s%X[0x%08X]=0x%X, got 0x%X from 0x%08X\n", - aspeed_pinmux_ips[desc->ip], desc->reg, - desc->mask, enable ? desc->enable : desc->disable, - (rv & desc->mask) >> __ffs(desc->mask), rv); -} - -/** - * Query the enabled or disabled state of a signal descriptor - * - * @desc: The signal descriptor of interest - * @enabled: True to query the enabled state, false to query disabled state - * @map: The IP block's regmap instance - * - * Return: 1 if the descriptor's bitfield is configured to the state - * selected by @enabled, 0 if not, and less than zero if an unrecoverable - * failure occurred - * - * Evaluation of descriptor state is non-trivial in that it is not a binary - * outcome: The bitfields can be greater than one bit in size and thus can take - * a value that is neither the enabled nor disabled state recorded in the - * descriptor (typically this means a different function to the one of interest - * is enabled). Thus we must explicitly test for either condition as required. - */ -static int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, - bool enabled, struct regmap *map) -{ - int ret; - unsigned int raw; - u32 want; - - if (!map) - return -ENODEV; - - ret = regmap_read(map, desc->reg, &raw); - if (ret) - return ret; - - aspeed_sig_desc_print_val(desc, enabled, raw); - want = enabled ? desc->enable : desc->disable; - - return ((raw & desc->mask) >> __ffs(desc->mask)) == want; -} - -/** - * Query the enabled or disabled state for a mux function's signal on a pin - * - * @expr: An expression controlling the signal for a mux function on a pin - * @enabled: True to query the enabled state, false to query disabled state - * @maps: The list of regmap instances - * - * Return: 1 if the expression composed by @enabled evaluates true, 0 if not, - * and less than zero if an unrecoverable failure occurred. - * - * A mux function is enabled or disabled if the function's signal expression - * for each pin in the function's pin group evaluates true for the desired - * state. An signal expression evaluates true if all of its associated signal - * descriptors evaluate true for the desired state. - * - * If an expression's state is described by more than one bit, either through - * multi-bit bitfields in a single signal descriptor or through multiple signal - * descriptors of a single bit then it is possible for the expression to be in - * neither the enabled nor disabled state. Thus we must explicitly test for - * either condition as required. - */ -static int aspeed_sig_expr_eval(const struct aspeed_sig_expr *expr, - bool enabled, struct regmap * const *maps) -{ - int i; - int ret; - - for (i = 0; i < expr->ndescs; i++) { - const struct aspeed_sig_desc *desc = &expr->descs[i]; - - ret = aspeed_sig_desc_eval(desc, enabled, maps[desc->ip]); - if (ret <= 0) - return ret; - } - - return 1; -} - -/** - * Configure a pin's signal by applying an expression's descriptor state for - * all descriptors in the expression. - * - * @expr: The expression associated with the function whose signal is to be - * configured - * @enable: true to enable an function's signal through a pin's signal - * expression, false to disable the function's signal - * @maps: The list of regmap instances for pinmux register access. - * - * Return: 0 if the expression is configured as requested and a negative error - * code otherwise - */ -static int aspeed_sig_expr_set(const struct aspeed_sig_expr *expr, - bool enable, struct regmap * const *maps) +static int aspeed_sig_expr_enable(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr *expr) { int ret; - int i; - - for (i = 0; i < expr->ndescs; i++) { - const struct aspeed_sig_desc *desc = &expr->descs[i]; - u32 pattern = enable ? desc->enable : desc->disable; - u32 val = (pattern << __ffs(desc->mask)); - - if (!maps[desc->ip]) - return -ENODEV; - - /* - * Strap registers are configured in hardware or by early-boot - * firmware. Treat them as read-only despite that we can write - * them. This may mean that certain functions cannot be - * deconfigured and is the reason we re-evaluate after writing - * all descriptor bits. - * - * Port D and port E GPIO loopback modes are the only exception - * as those are commonly used with front-panel buttons to allow - * normal operation of the host when the BMC is powered off or - * fails to boot. Once the BMC has booted, the loopback mode - * must be disabled for the BMC to control host power-on and - * reset. - */ - if (desc->ip == ASPEED_IP_SCU && desc->reg == HW_STRAP1 && - !(desc->mask & (BIT(21) | BIT(22)))) - continue; - - if (desc->ip == ASPEED_IP_SCU && desc->reg == HW_STRAP2) - continue; - /* On AST2500, Set bits in SCU7C are cleared from SCU70 */ - if (desc->ip == ASPEED_IP_SCU && desc->reg == HW_STRAP1) { - unsigned int rev_id; - - ret = regmap_read(maps[ASPEED_IP_SCU], - HW_REVISION_ID, &rev_id); - if (ret < 0) - return ret; - - if (0x04 == (rev_id >> 24)) { - u32 value = ~val & desc->mask; - - if (value) { - ret = regmap_write(maps[desc->ip], - HW_REVISION_ID, value); - if (ret < 0) - return ret; - } - } - } + pr_debug("Enabling signal %s for %s\n", expr->signal, + expr->function); - ret = regmap_update_bits(maps[desc->ip], desc->reg, - desc->mask, val); - - if (ret) - return ret; - } - - ret = aspeed_sig_expr_eval(expr, enable, maps); + ret = aspeed_sig_expr_eval(ctx, expr, true); if (ret < 0) return ret; if (!ret) - return -EPERM; + return aspeed_sig_expr_set(ctx, expr, true); return 0; } -static int aspeed_sig_expr_enable(const struct aspeed_sig_expr *expr, - struct regmap * const *maps) +static int aspeed_sig_expr_disable(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr *expr) { int ret; - ret = aspeed_sig_expr_eval(expr, true, maps); - if (ret < 0) - return ret; - - if (!ret) - return aspeed_sig_expr_set(expr, true, maps); - - return 0; -} - -static int aspeed_sig_expr_disable(const struct aspeed_sig_expr *expr, - struct regmap * const *maps) -{ - int ret; + pr_debug("Disabling signal %s for %s\n", expr->signal, + expr->function); - ret = aspeed_sig_expr_eval(expr, true, maps); + ret = aspeed_sig_expr_eval(ctx, expr, true); if (ret < 0) return ret; if (ret) - return aspeed_sig_expr_set(expr, false, maps); + return aspeed_sig_expr_set(ctx, expr, false); return 0; } /** - * Disable a signal on a pin by disabling all provided signal expressions. + * aspeed_disable_sig() - Disable a signal on a pin by disabling all provided + * signal expressions. * + * @ctx: The pinmux context * @exprs: The list of signal expressions (from a priority level on a pin) - * @maps: The list of regmap instances for pinmux register access. * * Return: 0 if all expressions are disabled, otherwise a negative error code */ -static int aspeed_disable_sig(const struct aspeed_sig_expr **exprs, - struct regmap * const *maps) +static int aspeed_disable_sig(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr **exprs) { int ret = 0; if (!exprs) - return true; + return -EINVAL; while (*exprs && !ret) { - ret = aspeed_sig_expr_disable(*exprs, maps); + ret = aspeed_sig_expr_disable(ctx, *exprs); exprs++; } @@ -306,8 +134,8 @@ static int aspeed_disable_sig(const struct aspeed_sig_expr **exprs, } /** - * Search for the signal expression needed to enable the pin's signal for the - * requested function. + * aspeed_find_expr_by_name - Search for the signal expression needed to + * enable the pin's signal for the requested function. * * @exprs: List of signal expressions (haystack) * @name: The name of the requested function (needle) @@ -397,11 +225,10 @@ int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, { int i; int ret; - const struct aspeed_pinctrl_data *pdata = - pinctrl_dev_get_drvdata(pctldev); - const struct aspeed_pin_group *pgroup = &pdata->groups[group]; + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + const struct aspeed_pin_group *pgroup = &pdata->pinmux.groups[group]; const struct aspeed_pin_function *pfunc = - &pdata->functions[function]; + &pdata->pinmux.functions[function]; for (i = 0; i < pgroup->npins; i++) { int pin = pgroup->pins[i]; @@ -410,11 +237,11 @@ int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, const struct aspeed_sig_expr **funcs; const struct aspeed_sig_expr ***prios; - pr_debug("Muxing pin %d for %s\n", pin, pfunc->name); - if (!pdesc) return -EINVAL; + pr_debug("Muxing pin %s for %s\n", pdesc->name, pfunc->name); + prios = pdesc->prios; if (!prios) @@ -427,7 +254,7 @@ int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, if (expr) break; - ret = aspeed_disable_sig(funcs, pdata->maps); + ret = aspeed_disable_sig(&pdata->pinmux, funcs); if (ret) return ret; @@ -447,9 +274,12 @@ int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, return -ENXIO; } - ret = aspeed_sig_expr_enable(expr, pdata->maps); + ret = aspeed_sig_expr_enable(&pdata->pinmux, expr); if (ret) return ret; + + pr_debug("Muxed pin %s as %s for %s\n", pdesc->name, expr->signal, + expr->function); } return 0; @@ -458,13 +288,76 @@ int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr) { /* - * The signal type is GPIO if the signal name has "GPIO" as a prefix. - * strncmp (rather than strcmp) is used to implement the prefix - * requirement. + * We need to differentiate between GPIO and non-GPIO signals to + * implement the gpio_request_enable() interface. For better or worse + * the ASPEED pinctrl driver uses the expression names to determine + * whether an expression will mux a pin for GPIO. + * + * Generally we have the following - A GPIO such as B1 has: + * + * - expr->signal set to "GPIOB1" + * - expr->function set to "GPIOB1" + * + * Using this fact we can determine whether the provided expression is + * a GPIO expression by testing the signal name for the string prefix + * "GPIO". + * + * However, some GPIOs are input-only, and the ASPEED datasheets name + * them differently. An input-only GPIO such as T0 has: + * + * - expr->signal set to "GPIT0" + * - expr->function set to "GPIT0" + * + * It's tempting to generalise the prefix test from "GPIO" to "GPI" to + * account for both GPIOs and GPIs, but in doing so we run aground on + * another feature: * - * expr->signal might look like "GPIOT3" in the GPIO case. + * Some pins in the ASPEED BMC SoCs have a "pass-through" GPIO + * function where the input state of one pin is replicated as the + * output state of another (as if they were shorted together - a mux + * configuration that is typically enabled by hardware strapping). + * This feature allows the BMC to pass e.g. power button state through + * to the host while the BMC is yet to boot, but take control of the + * button state once the BMC has booted by muxing each pin as a + * separate, pin-specific GPIO. + * + * Conceptually this pass-through mode is a form of GPIO and is named + * as such in the datasheets, e.g. "GPID0". This naming similarity + * trips us up with the simple GPI-prefixed-signal-name scheme + * discussed above, as the pass-through configuration is not what we + * want when muxing a pin as GPIO for the GPIO subsystem. + * + * On e.g. the AST2400, a pass-through function "GPID0" is grouped on + * balls A18 and D16, where we have: + * + * For ball A18: + * - expr->signal set to "GPID0IN" + * - expr->function set to "GPID0" + * + * For ball D16: + * - expr->signal set to "GPID0OUT" + * - expr->function set to "GPID0" + * + * By contrast, the pin-specific GPIO expressions for the same pins are + * as follows: + * + * For ball A18: + * - expr->signal looks like "GPIOD0" + * - expr->function looks like "GPIOD0" + * + * For ball D16: + * - expr->signal looks like "GPIOD1" + * - expr->function looks like "GPIOD1" + * + * Testing both the signal _and_ function names gives us the means + * differentiate the pass-through GPIO pinmux configuration from the + * pin-specific configuration that the GPIO subsystem is after: An + * expression is a pin-specific (non-pass-through) GPIO configuration + * if the signal prefix is "GPI" and the signal name matches the + * function name. */ - return strncmp(expr->signal, "GPIO", 4) == 0; + return !strncmp(expr->signal, "GPI", 3) && + !strcmp(expr->signal, expr->function); } static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs) @@ -486,8 +379,7 @@ int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, unsigned int offset) { int ret; - const struct aspeed_pinctrl_data *pdata = - pinctrl_dev_get_drvdata(pctldev); + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data; const struct aspeed_sig_expr ***prios, **funcs, *expr; @@ -499,12 +391,14 @@ int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, if (!prios) return -ENXIO; + pr_debug("Muxing pin %s for GPIO\n", pdesc->name); + /* Disable any functions of higher priority than GPIO */ while ((funcs = *prios)) { if (aspeed_gpio_in_exprs(funcs)) break; - ret = aspeed_disable_sig(funcs, pdata->maps); + ret = aspeed_disable_sig(&pdata->pinmux, funcs); if (ret) return ret; @@ -528,18 +422,26 @@ int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, * lowest-priority signal type. As such it has no associated * expression. */ - if (!expr) + if (!expr) { + pr_debug("Muxed pin %s as GPIO\n", pdesc->name); return 0; + } /* * If GPIO is not the lowest priority signal type, assume there is only * one expression defined to enable the GPIO function */ - return aspeed_sig_expr_enable(expr, pdata->maps); + ret = aspeed_sig_expr_enable(&pdata->pinmux, expr); + if (ret) + return ret; + + pr_debug("Muxed pin %s as %s\n", pdesc->name, expr->signal); + + return 0; } int aspeed_pinctrl_probe(struct platform_device *pdev, - struct pinctrl_desc *pdesc, + const struct pinctrl_desc *pdesc, struct aspeed_pinctrl_data *pdata) { struct device *parent; @@ -551,12 +453,14 @@ int aspeed_pinctrl_probe(struct platform_device *pdev, return -ENODEV; } - pdata->maps[ASPEED_IP_SCU] = syscon_node_to_regmap(parent->of_node); - if (IS_ERR(pdata->maps[ASPEED_IP_SCU])) { + pdata->scu = syscon_node_to_regmap(parent->of_node); + if (IS_ERR(pdata->scu)) { dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n"); - return PTR_ERR(pdata->maps[ASPEED_IP_SCU]); + return PTR_ERR(pdata->scu); } + pdata->pinmux.maps[ASPEED_IP_SCU] = pdata->scu; + pctl = pinctrl_register(pdesc, &pdev->dev, pdata); if (IS_ERR(pctl)) { @@ -591,47 +495,21 @@ static inline const struct aspeed_pin_config *find_pinconf_config( return NULL; } -/** - * @param: pinconf configuration parameter - * @arg: The supported argument for @param, or -1 if any value is supported - * @val: The register value to write to configure @arg for @param - * - * The map is to be used in conjunction with the configuration array supplied - * by the driver implementation. - */ -struct aspeed_pin_config_map { - enum pin_config_param param; - s32 arg; - u32 val; -}; - enum aspeed_pin_config_map_type { MAP_TYPE_ARG, MAP_TYPE_VAL }; -/* Aspeed consistently both: - * - * 1. Defines "disable bits" for internal pull-downs - * 2. Uses 8mA or 16mA drive strengths - */ -static const struct aspeed_pin_config_map pin_config_map[] = { - { PIN_CONFIG_BIAS_PULL_DOWN, 0, 1 }, - { PIN_CONFIG_BIAS_PULL_DOWN, -1, 0 }, - { PIN_CONFIG_BIAS_DISABLE, -1, 1 }, - { PIN_CONFIG_DRIVE_STRENGTH, 8, 0 }, - { PIN_CONFIG_DRIVE_STRENGTH, 16, 1 }, -}; - static const struct aspeed_pin_config_map *find_pinconf_map( + const struct aspeed_pinctrl_data *pdata, enum pin_config_param param, enum aspeed_pin_config_map_type type, s64 value) { int i; - for (i = 0; i < ARRAY_SIZE(pin_config_map); i++) { + for (i = 0; i < pdata->nconfmaps; i++) { const struct aspeed_pin_config_map *elem; bool match; - elem = &pin_config_map[i]; + elem = &pdata->confmaps[i]; switch (type) { case MAP_TYPE_ARG: @@ -665,12 +543,12 @@ int aspeed_pin_config_get(struct pinctrl_dev *pctldev, unsigned int offset, if (!pconf) return -ENOTSUPP; - rc = regmap_read(pdata->maps[ASPEED_IP_SCU], pconf->reg, &val); + rc = regmap_read(pdata->scu, pconf->reg, &val); if (rc < 0) return rc; - pmap = find_pinconf_map(param, MAP_TYPE_VAL, - (val & BIT(pconf->bit)) >> pconf->bit); + pmap = find_pinconf_map(pdata, param, MAP_TYPE_VAL, + (val & pconf->mask) >> __ffs(pconf->mask)); if (!pmap) return -EINVAL; @@ -713,22 +591,22 @@ int aspeed_pin_config_set(struct pinctrl_dev *pctldev, unsigned int offset, if (!pconf) return -ENOTSUPP; - pmap = find_pinconf_map(param, MAP_TYPE_ARG, arg); + pmap = find_pinconf_map(pdata, param, MAP_TYPE_ARG, arg); if (WARN_ON(!pmap)) return -EINVAL; - val = pmap->val << pconf->bit; + val = pmap->val << __ffs(pconf->mask); - rc = regmap_update_bits(pdata->maps[ASPEED_IP_SCU], pconf->reg, - BIT(pconf->bit), val); + rc = regmap_update_bits(pdata->scu, pconf->reg, + pconf->mask, val); if (rc < 0) return rc; - pr_debug("%s: Set SCU%02X[%d]=%d for param %d(=%d) on pin %d\n", - __func__, pconf->reg, pconf->bit, pmap->val, - param, arg, offset); + pr_debug("%s: Set SCU%02X[0x%08X]=0x%X for param %d(=%d) on pin %d\n", + __func__, pconf->reg, pconf->mask, + val, param, arg, offset); } return 0; |
