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Diffstat (limited to 'drivers/pinctrl/aspeed/pinctrl-aspeed.c')
-rw-r--r--drivers/pinctrl/aspeed/pinctrl-aspeed.c406
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;