diff options
Diffstat (limited to 'drivers/pinctrl/aspeed/pinctrl-aspeed.c')
| -rw-r--r-- | drivers/pinctrl/aspeed/pinctrl-aspeed.c | 782 |
1 files changed, 782 insertions, 0 deletions
diff --git a/drivers/pinctrl/aspeed/pinctrl-aspeed.c b/drivers/pinctrl/aspeed/pinctrl-aspeed.c new file mode 100644 index 000000000..8dec302dc --- /dev/null +++ b/drivers/pinctrl/aspeed/pinctrl-aspeed.c @@ -0,0 +1,782 @@ +/* + * 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/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; +} + +const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev, + unsigned int group) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + return pdata->groups[group].name; +} + +int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, + unsigned int group, const unsigned int **pins, + unsigned int *npins) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + *pins = &pdata->groups[group].pins[0]; + *npins = pdata->groups[group].npins; + + return 0; +} + +void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev, + struct seq_file *s, unsigned int offset) +{ + seq_printf(s, " %s", dev_name(pctldev->dev)); +} + +int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + return pdata->nfunctions; +} + +const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev, + unsigned int function) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + return pdata->functions[function].name; +} + +int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev, + unsigned int function, + const char * const **groups, + unsigned int * const num_groups) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + *groups = pdata->functions[function].groups; + *num_groups = pdata->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) +{ + 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; + } + } + } + + ret = regmap_update_bits(maps[desc->ip], desc->reg, + desc->mask, val); + + if (ret) + return ret; + } + + ret = aspeed_sig_expr_eval(expr, enable, maps); + if (ret < 0) + return ret; + + if (!ret) + return -EPERM; + + return 0; +} + +static int aspeed_sig_expr_enable(const struct aspeed_sig_expr *expr, + struct regmap * const *maps) +{ + 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; + + ret = aspeed_sig_expr_eval(expr, true, maps); + if (ret < 0) + return ret; + + if (ret) + return aspeed_sig_expr_set(expr, false, maps); + + return 0; +} + +/** + * Disable a signal on a pin by disabling all provided signal expressions. + * + * @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) +{ + int ret = 0; + + if (!exprs) + return true; + + while (*exprs && !ret) { + ret = aspeed_sig_expr_disable(*exprs, maps); + exprs++; + } + + return ret; +} + +/** + * 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) + * + * Return: A pointer to the signal expression whose function tag matches the + * provided name, otherwise NULL. + * + */ +static const struct aspeed_sig_expr *aspeed_find_expr_by_name( + const struct aspeed_sig_expr **exprs, const char *name) +{ + while (*exprs) { + if (strcmp((*exprs)->function, name) == 0) + return *exprs; + exprs++; + } + + return NULL; +} + +static char *get_defined_attribute(const struct aspeed_pin_desc *pdesc, + const char *(*get)( + const struct aspeed_sig_expr *)) +{ + char *found = NULL; + size_t len = 0; + const struct aspeed_sig_expr ***prios, **funcs, *expr; + + prios = pdesc->prios; + + while ((funcs = *prios)) { + while ((expr = *funcs)) { + const char *str = get(expr); + size_t delta = strlen(str) + 2; + char *expanded; + + expanded = krealloc(found, len + delta + 1, GFP_KERNEL); + if (!expanded) { + kfree(found); + return expanded; + } + + found = expanded; + found[len] = '\0'; + len += delta; + + strcat(found, str); + strcat(found, ", "); + + funcs++; + } + prios++; + } + + if (len < 2) { + kfree(found); + return NULL; + } + + found[len - 2] = '\0'; + + return found; +} + +static const char *aspeed_sig_expr_function(const struct aspeed_sig_expr *expr) +{ + return expr->function; +} + +static char *get_defined_functions(const struct aspeed_pin_desc *pdesc) +{ + return get_defined_attribute(pdesc, aspeed_sig_expr_function); +} + +static const char *aspeed_sig_expr_signal(const struct aspeed_sig_expr *expr) +{ + return expr->signal; +} + +static char *get_defined_signals(const struct aspeed_pin_desc *pdesc) +{ + return get_defined_attribute(pdesc, aspeed_sig_expr_signal); +} + +int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function, + unsigned int group) +{ + int i; + int ret; + const struct aspeed_pinctrl_data *pdata = + pinctrl_dev_get_drvdata(pctldev); + const struct aspeed_pin_group *pgroup = &pdata->groups[group]; + const struct aspeed_pin_function *pfunc = + &pdata->functions[function]; + + for (i = 0; i < pgroup->npins; i++) { + int pin = pgroup->pins[i]; + const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data; + const struct aspeed_sig_expr *expr = NULL; + 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; + + prios = pdesc->prios; + + if (!prios) + continue; + + /* Disable functions at a higher priority than that requested */ + while ((funcs = *prios)) { + expr = aspeed_find_expr_by_name(funcs, pfunc->name); + + if (expr) + break; + + ret = aspeed_disable_sig(funcs, pdata->maps); + if (ret) + return ret; + + prios++; + } + + if (!expr) { + char *functions = get_defined_functions(pdesc); + char *signals = get_defined_signals(pdesc); + + pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n", + pfunc->name, pdesc->name, pin, signals, + functions); + kfree(signals); + kfree(functions); + + return -ENXIO; + } + + ret = aspeed_sig_expr_enable(expr, pdata->maps); + if (ret) + return ret; + } + + return 0; +} + +static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr) +{ + /* + * The signal type is GPIO if the signal name has "GPI" as a prefix. + * strncmp (rather than strcmp) is used to implement the prefix + * requirement. + * + * expr->signal might look like "GPIOB1" in the GPIO case. + * expr->signal might look like "GPIT0" in the GPI case. + */ + return strncmp(expr->signal, "GPI", 3) == 0; +} + +static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs) +{ + if (!exprs) + return false; + + while (*exprs) { + if (aspeed_expr_is_gpio(*exprs)) + return true; + exprs++; + } + + return false; +} + +int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev, + struct pinctrl_gpio_range *range, + unsigned int offset) +{ + int ret; + const 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; + + if (!pdesc) + return -EINVAL; + + prios = pdesc->prios; + + if (!prios) + return -ENXIO; + + /* 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); + if (ret) + return ret; + + prios++; + } + + if (!funcs) { + char *signals = get_defined_signals(pdesc); + + pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n", + pdesc->name, offset, signals); + kfree(signals); + + return -ENXIO; + } + + expr = *funcs; + + /* + * Disabling all higher-priority expressions is enough to enable the + * lowest-priority signal type. As such it has no associated + * expression. + */ + if (!expr) + 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); +} + +int aspeed_pinctrl_probe(struct platform_device *pdev, + struct pinctrl_desc *pdesc, + struct aspeed_pinctrl_data *pdata) +{ + struct device *parent; + struct pinctrl_dev *pctl; + + parent = pdev->dev.parent; + if (!parent) { + dev_err(&pdev->dev, "No parent for syscon pincontroller\n"); + return -ENODEV; + } + + pdata->maps[ASPEED_IP_SCU] = syscon_node_to_regmap(parent->of_node); + if (IS_ERR(pdata->maps[ASPEED_IP_SCU])) { + dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n"); + return PTR_ERR(pdata->maps[ASPEED_IP_SCU]); + } + + pctl = pinctrl_register(pdesc, &pdev->dev, pdata); + + if (IS_ERR(pctl)) { + dev_err(&pdev->dev, "Failed to register pinctrl\n"); + return PTR_ERR(pctl); + } + + platform_set_drvdata(pdev, pdata); + + return 0; +} + +static inline bool pin_in_config_range(unsigned int offset, + const struct aspeed_pin_config *config) +{ + return offset >= config->pins[0] && offset <= config->pins[1]; +} + +static inline const struct aspeed_pin_config *find_pinconf_config( + const struct aspeed_pinctrl_data *pdata, + unsigned int offset, + enum pin_config_param param) +{ + unsigned int i; + + for (i = 0; i < pdata->nconfigs; i++) { + if (param == pdata->configs[i].param && + pin_in_config_range(offset, &pdata->configs[i])) + return &pdata->configs[i]; + } + + 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( + 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++) { + const struct aspeed_pin_config_map *elem; + bool match; + + elem = &pin_config_map[i]; + + switch (type) { + case MAP_TYPE_ARG: + match = (elem->arg == -1 || elem->arg == value); + break; + case MAP_TYPE_VAL: + match = (elem->val == value); + break; + } + + if (param == elem->param && match) + return elem; + } + + return NULL; +} + +int aspeed_pin_config_get(struct pinctrl_dev *pctldev, unsigned int offset, + unsigned long *config) +{ + const enum pin_config_param param = pinconf_to_config_param(*config); + const struct aspeed_pin_config_map *pmap; + const struct aspeed_pinctrl_data *pdata; + const struct aspeed_pin_config *pconf; + unsigned int val; + int rc = 0; + u32 arg; + + pdata = pinctrl_dev_get_drvdata(pctldev); + pconf = find_pinconf_config(pdata, offset, param); + if (!pconf) + return -ENOTSUPP; + + rc = regmap_read(pdata->maps[ASPEED_IP_SCU], pconf->reg, &val); + if (rc < 0) + return rc; + + pmap = find_pinconf_map(param, MAP_TYPE_VAL, + (val & BIT(pconf->bit)) >> pconf->bit); + + if (!pmap) + return -EINVAL; + + if (param == PIN_CONFIG_DRIVE_STRENGTH) + arg = (u32) pmap->arg; + else if (param == PIN_CONFIG_BIAS_PULL_DOWN) + arg = !!pmap->arg; + else + arg = 1; + + if (!arg) + return -EINVAL; + + *config = pinconf_to_config_packed(param, arg); + + return 0; +} + +int aspeed_pin_config_set(struct pinctrl_dev *pctldev, unsigned int offset, + unsigned long *configs, unsigned int num_configs) +{ + const struct aspeed_pinctrl_data *pdata; + unsigned int i; + int rc = 0; + + pdata = pinctrl_dev_get_drvdata(pctldev); + + for (i = 0; i < num_configs; i++) { + const struct aspeed_pin_config_map *pmap; + const struct aspeed_pin_config *pconf; + enum pin_config_param param; + unsigned int val; + u32 arg; + + param = pinconf_to_config_param(configs[i]); + arg = pinconf_to_config_argument(configs[i]); + + pconf = find_pinconf_config(pdata, offset, param); + if (!pconf) + return -ENOTSUPP; + + pmap = find_pinconf_map(param, MAP_TYPE_ARG, arg); + + if (unlikely(WARN_ON(!pmap))) + return -EINVAL; + + val = pmap->val << pconf->bit; + + rc = regmap_update_bits(pdata->maps[ASPEED_IP_SCU], pconf->reg, + BIT(pconf->bit), 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); + } + + return 0; +} + +int aspeed_pin_config_group_get(struct pinctrl_dev *pctldev, + unsigned int selector, + unsigned long *config) +{ + const unsigned int *pins; + unsigned int npins; + int rc; + + rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins); + if (rc < 0) + return rc; + + if (!npins) + return -ENODEV; + + rc = aspeed_pin_config_get(pctldev, pins[0], config); + + return rc; +} + +int aspeed_pin_config_group_set(struct pinctrl_dev *pctldev, + unsigned int selector, + unsigned long *configs, + unsigned int num_configs) +{ + const unsigned int *pins; + unsigned int npins; + int rc; + int i; + + pr_debug("%s: Fetching pins for group selector %d\n", + __func__, selector); + rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins); + if (rc < 0) + return rc; + + for (i = 0; i < npins; i++) { + rc = aspeed_pin_config_set(pctldev, pins[i], configs, + num_configs); + if (rc < 0) + return rc; + } + + return 0; +} |