diff options
Diffstat (limited to 'drivers/pinctrl/aspeed/pinctrl-aspeed.c')
| -rw-r--r-- | drivers/pinctrl/aspeed/pinctrl-aspeed.c | 658 |
1 files changed, 658 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..5a12fc7cf --- /dev/null +++ b/drivers/pinctrl/aspeed/pinctrl-aspeed.c @@ -0,0 +1,658 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2016 IBM Corp. + */ + +#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" + +int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) +{ + struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev); + + return pdata->pinmux.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->pinmux.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->pinmux.groups[group].pins[0]; + *npins = pdata->pinmux.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->pinmux.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->pinmux.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->pinmux.functions[function].groups; + *num_groups = pdata->pinmux.functions[function].ngroups; + + return 0; +} + +static int aspeed_sig_expr_enable(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr *expr) +{ + int ret; + + pr_debug("Enabling signal %s for %s\n", expr->signal, + expr->function); + + ret = aspeed_sig_expr_eval(ctx, expr, true); + if (ret < 0) + return ret; + + if (!ret) + return aspeed_sig_expr_set(ctx, expr, true); + + return 0; +} + +static int aspeed_sig_expr_disable(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr *expr) +{ + int ret; + + pr_debug("Disabling signal %s for %s\n", expr->signal, + expr->function); + + ret = aspeed_sig_expr_eval(ctx, expr, true); + if (ret < 0) + return ret; + + if (ret) + return aspeed_sig_expr_set(ctx, expr, false); + + return 0; +} + +/** + * 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) + * + * Return: 0 if all expressions are disabled, otherwise a negative error code + */ +static int aspeed_disable_sig(struct aspeed_pinmux_data *ctx, + const struct aspeed_sig_expr **exprs) +{ + int ret = 0; + + if (!exprs) + return -EINVAL; + + while (*exprs && !ret) { + ret = aspeed_sig_expr_disable(ctx, *exprs); + exprs++; + } + + return ret; +} + +/** + * 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) + * + * 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; + 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->pinmux.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; + + if (!pdesc) + return -EINVAL; + + pr_debug("Muxing pin %s for %s\n", pdesc->name, pfunc->name); + + 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(&pdata->pinmux, funcs); + 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(&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; +} + +static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr) +{ + /* + * 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: + * + * 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, "GPI", 3) && + !strcmp(expr->signal, expr->function); +} + +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; + 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; + + 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(&pdata->pinmux, funcs); + 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) { + 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 + */ + 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, + 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->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->scu); + } + + pdata->pinmux.maps[ASPEED_IP_SCU] = pdata->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; +} + +enum aspeed_pin_config_map_type { MAP_TYPE_ARG, MAP_TYPE_VAL }; + +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 < pdata->nconfmaps; i++) { + const struct aspeed_pin_config_map *elem; + bool match; + + elem = &pdata->confmaps[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->scu, pconf->reg, &val); + if (rc < 0) + return rc; + + pmap = find_pinconf_map(pdata, param, MAP_TYPE_VAL, + (val & pconf->mask) >> __ffs(pconf->mask)); + + 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(pdata, param, MAP_TYPE_ARG, arg); + + if (WARN_ON(!pmap)) + return -EINVAL; + + val = pmap->val << __ffs(pconf->mask); + + rc = regmap_update_bits(pdata->scu, pconf->reg, + pconf->mask, val); + + if (rc < 0) + return rc; + + 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; +} + +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; +} |