linux/drivers/pinctrl/pinmux.c
Tony Lindgren f913cfce4e pinctrl: pinmux: Return selector to the pinctrl driver
We must return the selector from pinmux_generic_add_function() so
pin controller device drivers can remove the right group if needed
for deferred probe for example. And we now must make sure that a
proper name is passed so we can use it to check if the entry already
exists.

Note that fixes are also needed for the pin controller drivers to
use the selector value.

Fixes: a76edc89b1 ("pinctrl: core: Add generic pinctrl functions for
managing groups")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Christ van Willegen <cvwillegen@gmail.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-By: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-07-17 10:48:47 +02:00

850 lines
21 KiB
C

/*
* Core driver for the pin muxing portions of the pin control subsystem
*
* Copyright (C) 2011-2012 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
* Based on bits of regulator core, gpio core and clk core
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
*
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) "pinmux core: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinmux.h>
#include "core.h"
#include "pinmux.h"
int pinmux_check_ops(struct pinctrl_dev *pctldev)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned nfuncs;
unsigned selector = 0;
/* Check that we implement required operations */
if (!ops ||
!ops->get_functions_count ||
!ops->get_function_name ||
!ops->get_function_groups ||
!ops->set_mux) {
dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
return -EINVAL;
}
/* Check that all functions registered have names */
nfuncs = ops->get_functions_count(pctldev);
while (selector < nfuncs) {
const char *fname = ops->get_function_name(pctldev,
selector);
if (!fname) {
dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
selector);
return -EINVAL;
}
selector++;
}
return 0;
}
int pinmux_validate_map(const struct pinctrl_map *map, int i)
{
if (!map->data.mux.function) {
pr_err("failed to register map %s (%d): no function given\n",
map->name, i);
return -EINVAL;
}
return 0;
}
/**
* pin_request() - request a single pin to be muxed in, typically for GPIO
* @pin: the pin number in the global pin space
* @owner: a representation of the owner of this pin; typically the device
* name that controls its mux function, or the requested GPIO name
* @gpio_range: the range matching the GPIO pin if this is a request for a
* single GPIO pin
*/
static int pin_request(struct pinctrl_dev *pctldev,
int pin, const char *owner,
struct pinctrl_gpio_range *gpio_range)
{
struct pin_desc *desc;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
int status = -EINVAL;
desc = pin_desc_get(pctldev, pin);
if (desc == NULL) {
dev_err(pctldev->dev,
"pin %d is not registered so it cannot be requested\n",
pin);
goto out;
}
dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
pin, desc->name, owner);
if ((!gpio_range || ops->strict) &&
desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
dev_err(pctldev->dev,
"pin %s already requested by %s; cannot claim for %s\n",
desc->name, desc->mux_owner, owner);
goto out;
}
if ((gpio_range || ops->strict) && desc->gpio_owner) {
dev_err(pctldev->dev,
"pin %s already requested by %s; cannot claim for %s\n",
desc->name, desc->gpio_owner, owner);
goto out;
}
if (gpio_range) {
desc->gpio_owner = owner;
} else {
desc->mux_usecount++;
if (desc->mux_usecount > 1)
return 0;
desc->mux_owner = owner;
}
/* Let each pin increase references to this module */
if (!try_module_get(pctldev->owner)) {
dev_err(pctldev->dev,
"could not increase module refcount for pin %d\n",
pin);
status = -EINVAL;
goto out_free_pin;
}
/*
* If there is no kind of request function for the pin we just assume
* we got it by default and proceed.
*/
if (gpio_range && ops->gpio_request_enable)
/* This requests and enables a single GPIO pin */
status = ops->gpio_request_enable(pctldev, gpio_range, pin);
else if (ops->request)
status = ops->request(pctldev, pin);
else
status = 0;
if (status) {
dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
module_put(pctldev->owner);
}
out_free_pin:
if (status) {
if (gpio_range) {
desc->gpio_owner = NULL;
} else {
desc->mux_usecount--;
if (!desc->mux_usecount)
desc->mux_owner = NULL;
}
}
out:
if (status)
dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
pin, owner, status);
return status;
}
/**
* pin_free() - release a single muxed in pin so something else can be muxed
* @pctldev: pin controller device handling this pin
* @pin: the pin to free
* @gpio_range: the range matching the GPIO pin if this is a request for a
* single GPIO pin
*
* This function returns a pointer to the previous owner. This is used
* for callers that dynamically allocate an owner name so it can be freed
* once the pin is free. This is done for GPIO request functions.
*/
static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
struct pinctrl_gpio_range *gpio_range)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pin_desc *desc;
const char *owner;
desc = pin_desc_get(pctldev, pin);
if (desc == NULL) {
dev_err(pctldev->dev,
"pin is not registered so it cannot be freed\n");
return NULL;
}
if (!gpio_range) {
/*
* A pin should not be freed more times than allocated.
*/
if (WARN_ON(!desc->mux_usecount))
return NULL;
desc->mux_usecount--;
if (desc->mux_usecount)
return NULL;
}
/*
* If there is no kind of request function for the pin we just assume
* we got it by default and proceed.
*/
if (gpio_range && ops->gpio_disable_free)
ops->gpio_disable_free(pctldev, gpio_range, pin);
else if (ops->free)
ops->free(pctldev, pin);
if (gpio_range) {
owner = desc->gpio_owner;
desc->gpio_owner = NULL;
} else {
owner = desc->mux_owner;
desc->mux_owner = NULL;
desc->mux_setting = NULL;
}
module_put(pctldev->owner);
return owner;
}
/**
* pinmux_request_gpio() - request pinmuxing for a GPIO pin
* @pctldev: pin controller device affected
* @pin: the pin to mux in for GPIO
* @range: the applicable GPIO range
*/
int pinmux_request_gpio(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned pin, unsigned gpio)
{
const char *owner;
int ret;
/* Conjure some name stating what chip and pin this is taken by */
owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
if (!owner)
return -ENOMEM;
ret = pin_request(pctldev, pin, owner, range);
if (ret < 0)
kfree(owner);
return ret;
}
/**
* pinmux_free_gpio() - release a pin from GPIO muxing
* @pctldev: the pin controller device for the pin
* @pin: the affected currently GPIO-muxed in pin
* @range: applicable GPIO range
*/
void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
struct pinctrl_gpio_range *range)
{
const char *owner;
owner = pin_free(pctldev, pin, range);
kfree(owner);
}
/**
* pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
* @pctldev: the pin controller handling this pin
* @range: applicable GPIO range
* @pin: the affected GPIO pin in this controller
* @input: true if we set the pin as input, false for output
*/
int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned pin, bool input)
{
const struct pinmux_ops *ops;
int ret;
ops = pctldev->desc->pmxops;
if (ops->gpio_set_direction)
ret = ops->gpio_set_direction(pctldev, range, pin, input);
else
ret = 0;
return ret;
}
static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
const char *function)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned nfuncs = ops->get_functions_count(pctldev);
unsigned selector = 0;
/* See if this pctldev has this function */
while (selector < nfuncs) {
const char *fname = ops->get_function_name(pctldev, selector);
if (!strcmp(function, fname))
return selector;
selector++;
}
return -EINVAL;
}
int pinmux_map_to_setting(const struct pinctrl_map *map,
struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
char const * const *groups;
unsigned num_groups;
int ret;
const char *group;
if (!pmxops) {
dev_err(pctldev->dev, "does not support mux function\n");
return -EINVAL;
}
ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
if (ret < 0) {
dev_err(pctldev->dev, "invalid function %s in map table\n",
map->data.mux.function);
return ret;
}
setting->data.mux.func = ret;
ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
&groups, &num_groups);
if (ret < 0) {
dev_err(pctldev->dev, "can't query groups for function %s\n",
map->data.mux.function);
return ret;
}
if (!num_groups) {
dev_err(pctldev->dev,
"function %s can't be selected on any group\n",
map->data.mux.function);
return -EINVAL;
}
if (map->data.mux.group) {
group = map->data.mux.group;
ret = match_string(groups, num_groups, group);
if (ret < 0) {
dev_err(pctldev->dev,
"invalid group \"%s\" for function \"%s\"\n",
group, map->data.mux.function);
return ret;
}
} else {
group = groups[0];
}
ret = pinctrl_get_group_selector(pctldev, group);
if (ret < 0) {
dev_err(pctldev->dev, "invalid group %s in map table\n",
map->data.mux.group);
return ret;
}
setting->data.mux.group = ret;
return 0;
}
void pinmux_free_setting(const struct pinctrl_setting *setting)
{
/* This function is currently unused */
}
int pinmux_enable_setting(const struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
int ret = 0;
const unsigned *pins = NULL;
unsigned num_pins = 0;
int i;
struct pin_desc *desc;
if (pctlops->get_group_pins)
ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
&pins, &num_pins);
if (ret) {
const char *gname;
/* errors only affect debug data, so just warn */
gname = pctlops->get_group_name(pctldev,
setting->data.mux.group);
dev_warn(pctldev->dev,
"could not get pins for group %s\n",
gname);
num_pins = 0;
}
/* Try to allocate all pins in this group, one by one */
for (i = 0; i < num_pins; i++) {
ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
if (ret) {
const char *gname;
const char *pname;
desc = pin_desc_get(pctldev, pins[i]);
pname = desc ? desc->name : "non-existing";
gname = pctlops->get_group_name(pctldev,
setting->data.mux.group);
dev_err(pctldev->dev,
"could not request pin %d (%s) from group %s "
" on device %s\n",
pins[i], pname, gname,
pinctrl_dev_get_name(pctldev));
goto err_pin_request;
}
}
/* Now that we have acquired the pins, encode the mux setting */
for (i = 0; i < num_pins; i++) {
desc = pin_desc_get(pctldev, pins[i]);
if (desc == NULL) {
dev_warn(pctldev->dev,
"could not get pin desc for pin %d\n",
pins[i]);
continue;
}
desc->mux_setting = &(setting->data.mux);
}
ret = ops->set_mux(pctldev, setting->data.mux.func,
setting->data.mux.group);
if (ret)
goto err_set_mux;
return 0;
err_set_mux:
for (i = 0; i < num_pins; i++) {
desc = pin_desc_get(pctldev, pins[i]);
if (desc)
desc->mux_setting = NULL;
}
err_pin_request:
/* On error release all taken pins */
while (--i >= 0)
pin_free(pctldev, pins[i], NULL);
return ret;
}
void pinmux_disable_setting(const struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
int ret = 0;
const unsigned *pins = NULL;
unsigned num_pins = 0;
int i;
struct pin_desc *desc;
if (pctlops->get_group_pins)
ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
&pins, &num_pins);
if (ret) {
const char *gname;
/* errors only affect debug data, so just warn */
gname = pctlops->get_group_name(pctldev,
setting->data.mux.group);
dev_warn(pctldev->dev,
"could not get pins for group %s\n",
gname);
num_pins = 0;
}
/* Flag the descs that no setting is active */
for (i = 0; i < num_pins; i++) {
desc = pin_desc_get(pctldev, pins[i]);
if (desc == NULL) {
dev_warn(pctldev->dev,
"could not get pin desc for pin %d\n",
pins[i]);
continue;
}
if (desc->mux_setting == &(setting->data.mux)) {
pin_free(pctldev, pins[i], NULL);
} else {
const char *gname;
gname = pctlops->get_group_name(pctldev,
setting->data.mux.group);
dev_warn(pctldev->dev,
"not freeing pin %d (%s) as part of "
"deactivating group %s - it is already "
"used for some other setting",
pins[i], desc->name, gname);
}
}
}
#ifdef CONFIG_DEBUG_FS
/* Called from pincontrol core */
static int pinmux_functions_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
unsigned nfuncs;
unsigned func_selector = 0;
if (!pmxops)
return 0;
mutex_lock(&pctldev->mutex);
nfuncs = pmxops->get_functions_count(pctldev);
while (func_selector < nfuncs) {
const char *func = pmxops->get_function_name(pctldev,
func_selector);
const char * const *groups;
unsigned num_groups;
int ret;
int i;
ret = pmxops->get_function_groups(pctldev, func_selector,
&groups, &num_groups);
if (ret) {
seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
func);
func_selector++;
continue;
}
seq_printf(s, "function: %s, groups = [ ", func);
for (i = 0; i < num_groups; i++)
seq_printf(s, "%s ", groups[i]);
seq_puts(s, "]\n");
func_selector++;
}
mutex_unlock(&pctldev->mutex);
return 0;
}
static int pinmux_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
unsigned i, pin;
if (!pmxops)
return 0;
seq_puts(s, "Pinmux settings per pin\n");
if (pmxops->strict)
seq_puts(s,
"Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
else
seq_puts(s,
"Format: pin (name): mux_owner gpio_owner hog?\n");
mutex_lock(&pctldev->mutex);
/* The pin number can be retrived from the pin controller descriptor */
for (i = 0; i < pctldev->desc->npins; i++) {
struct pin_desc *desc;
bool is_hog = false;
pin = pctldev->desc->pins[i].number;
desc = pin_desc_get(pctldev, pin);
/* Skip if we cannot search the pin */
if (desc == NULL)
continue;
if (desc->mux_owner &&
!strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
is_hog = true;
if (pmxops->strict) {
if (desc->mux_owner)
seq_printf(s, "pin %d (%s): device %s%s",
pin, desc->name, desc->mux_owner,
is_hog ? " (HOG)" : "");
else if (desc->gpio_owner)
seq_printf(s, "pin %d (%s): GPIO %s",
pin, desc->name, desc->gpio_owner);
else
seq_printf(s, "pin %d (%s): UNCLAIMED",
pin, desc->name);
} else {
/* For non-strict controllers */
seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
desc->mux_owner ? desc->mux_owner
: "(MUX UNCLAIMED)",
desc->gpio_owner ? desc->gpio_owner
: "(GPIO UNCLAIMED)",
is_hog ? " (HOG)" : "");
}
/* If mux: print function+group claiming the pin */
if (desc->mux_setting)
seq_printf(s, " function %s group %s\n",
pmxops->get_function_name(pctldev,
desc->mux_setting->func),
pctlops->get_group_name(pctldev,
desc->mux_setting->group));
else
seq_putc(s, '\n');
}
mutex_unlock(&pctldev->mutex);
return 0;
}
void pinmux_show_map(struct seq_file *s, const struct pinctrl_map *map)
{
seq_printf(s, "group %s\nfunction %s\n",
map->data.mux.group ? map->data.mux.group : "(default)",
map->data.mux.function);
}
void pinmux_show_setting(struct seq_file *s,
const struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
seq_printf(s, "group: %s (%u) function: %s (%u)\n",
pctlops->get_group_name(pctldev, setting->data.mux.group),
setting->data.mux.group,
pmxops->get_function_name(pctldev, setting->data.mux.func),
setting->data.mux.func);
}
static int pinmux_functions_open(struct inode *inode, struct file *file)
{
return single_open(file, pinmux_functions_show, inode->i_private);
}
static int pinmux_pins_open(struct inode *inode, struct file *file)
{
return single_open(file, pinmux_pins_show, inode->i_private);
}
static const struct file_operations pinmux_functions_ops = {
.open = pinmux_functions_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinmux_pins_ops = {
.open = pinmux_pins_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
void pinmux_init_device_debugfs(struct dentry *devroot,
struct pinctrl_dev *pctldev)
{
debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
devroot, pctldev, &pinmux_functions_ops);
debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
devroot, pctldev, &pinmux_pins_ops);
}
#endif /* CONFIG_DEBUG_FS */
#ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
/**
* pinmux_generic_get_function_count() - returns number of functions
* @pctldev: pin controller device
*/
int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
{
return pctldev->num_functions;
}
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
/**
* pinmux_generic_get_function_name() - returns the function name
* @pctldev: pin controller device
* @selector: function number
*/
const char *
pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
unsigned int selector)
{
struct function_desc *function;
function = radix_tree_lookup(&pctldev->pin_function_tree,
selector);
if (!function)
return NULL;
return function->name;
}
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
/**
* pinmux_generic_get_function_groups() - gets the function groups
* @pctldev: pin controller device
* @selector: function number
* @groups: array of pin groups
* @num_groups: number of pin groups
*/
int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
unsigned int selector,
const char * const **groups,
unsigned * const num_groups)
{
struct function_desc *function;
function = radix_tree_lookup(&pctldev->pin_function_tree,
selector);
if (!function) {
dev_err(pctldev->dev, "%s could not find function%i\n",
__func__, selector);
return -EINVAL;
}
*groups = function->group_names;
*num_groups = function->num_group_names;
return 0;
}
EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
/**
* pinmux_generic_get_function() - returns a function based on the number
* @pctldev: pin controller device
* @group_selector: function number
*/
struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
unsigned int selector)
{
struct function_desc *function;
function = radix_tree_lookup(&pctldev->pin_function_tree,
selector);
if (!function)
return NULL;
return function;
}
EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
/**
* pinmux_generic_add_function() - adds a function group
* @pctldev: pin controller device
* @name: name of the function
* @groups: array of pin groups
* @num_groups: number of pin groups
* @data: pin controller driver specific data
*/
int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
const char *name,
const char **groups,
const unsigned int num_groups,
void *data)
{
struct function_desc *function;
int selector;
if (!name)
return -EINVAL;
selector = pinmux_func_name_to_selector(pctldev, name);
if (selector >= 0)
return selector;
selector = pctldev->num_functions;
function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
if (!function)
return -ENOMEM;
function->name = name;
function->group_names = groups;
function->num_group_names = num_groups;
function->data = data;
radix_tree_insert(&pctldev->pin_function_tree, selector, function);
pctldev->num_functions++;
return selector;
}
EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
/**
* pinmux_generic_remove_function() - removes a numbered function
* @pctldev: pin controller device
* @selector: function number
*
* Note that the caller must take care of locking.
*/
int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
unsigned int selector)
{
struct function_desc *function;
function = radix_tree_lookup(&pctldev->pin_function_tree,
selector);
if (!function)
return -ENOENT;
radix_tree_delete(&pctldev->pin_function_tree, selector);
devm_kfree(pctldev->dev, function);
pctldev->num_functions--;
return 0;
}
EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
/**
* pinmux_generic_free_functions() - removes all functions
* @pctldev: pin controller device
*
* Note that the caller must take care of locking. The pinctrl
* functions are allocated with devm_kzalloc() so no need to free
* them here.
*/
void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
{
struct radix_tree_iter iter;
void __rcu **slot;
radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
radix_tree_delete(&pctldev->pin_function_tree, iter.index);
pctldev->num_functions = 0;
}
#endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */