linux/drivers/pinctrl/aspeed/pinctrl-aspeed.c
Randy Dunlap 5fa9d19b3f pinctrl: aspeed: placate kernel-doc warnings
Eliminate kernel-doc warnings in drivers/pinctrl/aspeed by using
proper kernel-doc notation.

Fixes these kernel-doc warnings:

drivers/pinctrl/aspeed/pinmux-aspeed.c:61: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * Query the enabled or disabled state for a mux function's signal on a pin
drivers/pinctrl/aspeed/pinctrl-aspeed.c:135: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
    * Search for the signal expression needed to enable the pin's signal for the

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: linux-aspeed@lists.ozlabs.org
Cc: openbmc@lists.ozlabs.org
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20210723034840.8752-1-rdunlap@infradead.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2021-08-10 15:29:44 +02:00

659 lines
16 KiB
C

// 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 true;
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;
pr_debug("Muxing pin %s for %s\n", pdesc->name, 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(&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;
}