kernel_optimize_test/drivers/pinctrl/pinmux.c
Stephen Warren d4e3198736 pinctrl: enhance pinctrl_get() to handle multiple functions
At present, pinctrl_get() assumes that all matching mapping table entries
have the same "function" value, albeit potentially applied to different
pins/groups.

This change removes this restriction; pinctrl_get() can now handle a set
of mapping tables where different functions are applied to the various
pins/groups.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 16:12:03 +01:00

701 lines
18 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>
*
* 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/mutex.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/sysfs.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"
/**
* struct pinmux_group - group list item for pinmux groups
* @node: pinmux group list node
* @func_selector: the function selector for the pinmux device handling
* this pinmux
* @group_selector: the group selector for this group
*/
struct pinmux_group {
struct list_head node;
unsigned func_selector;
unsigned group_selector;
};
int pinmux_check_ops(struct pinctrl_dev *pctldev)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned selector = 0;
/* Check that we implement required operations */
if (!ops->list_functions ||
!ops->get_function_name ||
!ops->get_function_groups ||
!ops->enable ||
!ops->disable)
return -EINVAL;
/* Check that all functions registered have names */
while (ops->list_functions(pctldev, selector) >= 0) {
const char *fname = ops->get_function_name(pctldev,
selector);
if (!fname) {
pr_err("pinmux ops has no name for function%u\n",
selector);
return -EINVAL;
}
selector++;
}
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;
dev_dbg(pctldev->dev, "request pin %d for %s\n", pin, owner);
desc = pin_desc_get(pctldev, pin);
if (desc == NULL) {
dev_err(pctldev->dev,
"pin is not registered so it cannot be requested\n");
goto out;
}
spin_lock(&desc->lock);
if (desc->owner && strcmp(desc->owner, owner)) {
spin_unlock(&desc->lock);
dev_err(pctldev->dev,
"pin already requested\n");
goto out;
}
desc->owner = owner;
spin_unlock(&desc->lock);
/* 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 on device %s failed for pin %d\n",
pctldev->desc->name, pin);
out_free_pin:
if (status) {
spin_lock(&desc->lock);
desc->owner = NULL;
spin_unlock(&desc->lock);
}
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 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);
spin_lock(&desc->lock);
owner = desc->owner;
desc->owner = NULL;
spin_unlock(&desc->lock);
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)
{
char gpiostr[16];
const char *owner;
int ret;
/* Conjure some name stating what chip and pin this is taken by */
snprintf(gpiostr, 15, "%s:%d", range->name, gpio);
owner = kstrdup(gpiostr, GFP_KERNEL);
if (!owner)
return -EINVAL;
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;
}
/**
* acquire_pins() - acquire all the pins for a certain function on a pinmux
* @pctldev: the device to take the pins on
* @owner: a representation of the owner of this pin; typically the device
* name that controls its mux function
* @group_selector: the group selector containing the pins to acquire
*/
static int acquire_pins(struct pinctrl_dev *pctldev,
const char *owner,
unsigned group_selector)
{
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const unsigned *pins;
unsigned num_pins;
int ret;
int i;
ret = pctlops->get_group_pins(pctldev, group_selector,
&pins, &num_pins);
if (ret)
return ret;
dev_dbg(pctldev->dev, "requesting the %u pins from group %u\n",
num_pins, group_selector);
/* Try to allocate all pins in this group, one by one */
for (i = 0; i < num_pins; i++) {
ret = pin_request(pctldev, pins[i], owner, NULL);
if (ret) {
dev_err(pctldev->dev,
"could not get request pin %d on device %s - conflicting mux mappings?\n",
pins[i],
pinctrl_dev_get_name(pctldev));
/* On error release all taken pins */
i--; /* this pin just failed */
for (; i >= 0; i--)
pin_free(pctldev, pins[i], NULL);
return -ENODEV;
}
}
return 0;
}
/**
* release_pins() - release pins taken by earlier acquirement
* @pctldev: the device to free the pins on
* @group_selector: the group selector containing the pins to free
*/
static void release_pins(struct pinctrl_dev *pctldev,
unsigned group_selector)
{
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const unsigned *pins;
unsigned num_pins;
int ret;
int i;
ret = pctlops->get_group_pins(pctldev, group_selector,
&pins, &num_pins);
if (ret) {
dev_err(pctldev->dev, "could not get pins to release for group selector %d\n",
group_selector);
return;
}
for (i = 0; i < num_pins; i++)
pin_free(pctldev, pins[i], NULL);
}
/**
* pinmux_check_pin_group() - check function and pin group combo
* @pctldev: device to check the pin group vs function for
* @func_selector: the function selector to check the pin group for, we have
* already looked this up in the calling function
* @pin_group: the pin group to match to the function
*
* This function will check that the pinmux driver can supply the
* selected pin group for a certain function, returns the group selector if
* the group and function selector will work fine together, else returns
* negative
*/
static int pinmux_check_pin_group(struct pinctrl_dev *pctldev,
unsigned func_selector,
const char *pin_group)
{
const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
int ret;
/*
* If the driver does not support different pin groups for the
* functions, we only support group 0, and assume this exists.
*/
if (!pctlops || !pctlops->list_groups)
return 0;
/*
* Passing NULL (no specific group) will select the first and
* hopefully only group of pins available for this function.
*/
if (!pin_group) {
char const * const *groups;
unsigned num_groups;
ret = pmxops->get_function_groups(pctldev, func_selector,
&groups, &num_groups);
if (ret)
return ret;
if (num_groups < 1)
return -EINVAL;
ret = pinctrl_get_group_selector(pctldev, groups[0]);
if (ret < 0) {
dev_err(pctldev->dev,
"function %s wants group %s but the pin controller does not seem to have that group\n",
pmxops->get_function_name(pctldev, func_selector),
groups[0]);
return ret;
}
if (num_groups > 1)
dev_dbg(pctldev->dev,
"function %s support more than one group, default-selecting first group %s (%d)\n",
pmxops->get_function_name(pctldev, func_selector),
groups[0],
ret);
return ret;
}
dev_dbg(pctldev->dev,
"check if we have pin group %s on controller %s\n",
pin_group, pinctrl_dev_get_name(pctldev));
ret = pinctrl_get_group_selector(pctldev, pin_group);
if (ret < 0) {
dev_dbg(pctldev->dev,
"%s does not support pin group %s with function %s\n",
pinctrl_dev_get_name(pctldev),
pin_group,
pmxops->get_function_name(pctldev, func_selector));
}
return ret;
}
/**
* pinmux_search_function() - check pin control driver for a certain function
* @pctldev: device to check for function and position
* @map: function map containing the function and position to look for
* @func_selector: returns the applicable function selector if found
* @group_selector: returns the applicable group selector if found
*
* This will search the pinmux driver for an applicable
* function with a specific pin group, returns 0 if these can be mapped
* negative otherwise
*/
static int pinmux_search_function(struct pinctrl_dev *pctldev,
struct pinctrl_map const *map,
unsigned *func_selector,
unsigned *group_selector)
{
const struct pinmux_ops *ops = pctldev->desc->pmxops;
unsigned selector = 0;
/* See if this pctldev has this function */
while (ops->list_functions(pctldev, selector) >= 0) {
const char *fname = ops->get_function_name(pctldev,
selector);
int ret;
if (!strcmp(map->function, fname)) {
/* Found the function, check pin group */
ret = pinmux_check_pin_group(pctldev, selector,
map->group);
if (ret < 0)
return ret;
/* This function and group selector can be used */
*func_selector = selector;
*group_selector = ret;
return 0;
}
selector++;
}
pr_err("%s does not support function %s\n",
pinctrl_dev_get_name(pctldev), map->function);
return -EINVAL;
}
/**
* pinmux_enable_muxmap() - enable a map entry for a certain pinmux
*/
static int pinmux_enable_muxmap(struct pinctrl_dev *pctldev,
struct pinctrl *p,
struct device *dev,
const char *devname,
struct pinctrl_map const *map)
{
unsigned func_selector;
unsigned group_selector;
struct pinmux_group *grp;
int ret;
/*
* Note that we're not locking the pinmux mutex here, because
* this is only called at pinmux initialization time when it
* has not been added to any list and thus is not reachable
* by anyone else.
*/
if (p->pctldev && p->pctldev != pctldev) {
dev_err(pctldev->dev,
"different pin control devices given for device %s, function %s\n",
devname, map->function);
return -EINVAL;
}
p->dev = dev;
p->pctldev = pctldev;
/* Now go into the driver and try to match a function and group */
ret = pinmux_search_function(pctldev, map, &func_selector,
&group_selector);
if (ret < 0)
return ret;
/* Now add this group selector, we may have many of them */
grp = kmalloc(sizeof(*grp), GFP_KERNEL);
if (!grp)
return -ENOMEM;
grp->func_selector = func_selector;
grp->group_selector = group_selector;
ret = acquire_pins(pctldev, devname, group_selector);
if (ret) {
kfree(grp);
return ret;
}
list_add_tail(&grp->node, &p->groups);
return 0;
}
/**
* pinmux_apply_muxmap() - apply a certain mux mapping entry
*/
int pinmux_apply_muxmap(struct pinctrl_dev *pctldev,
struct pinctrl *p,
struct device *dev,
const char *devname,
struct pinctrl_map const *map)
{
int ret;
ret = pinmux_enable_muxmap(pctldev, p, dev,
devname, map);
if (ret) {
pinmux_put(p);
return ret;
}
return 0;
}
/**
* pinmux_put() - free up the pinmux portions of a pin controller handle
*/
void pinmux_put(struct pinctrl *p)
{
struct list_head *node, *tmp;
list_for_each_safe(node, tmp, &p->groups) {
struct pinmux_group *grp =
list_entry(node, struct pinmux_group, node);
/* Release all pins taken by this group */
release_pins(p->pctldev, grp->group_selector);
list_del(node);
kfree(grp);
}
}
/**
* pinmux_enable() - enable the pinmux portion of a pin control handle
*/
int pinmux_enable(struct pinctrl *p)
{
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pinmux_group *grp;
int ret;
list_for_each_entry(grp, &p->groups, node) {
ret = ops->enable(pctldev, grp->func_selector,
grp->group_selector);
if (ret)
/*
* TODO: call disable() on all groups we called
* enable() on to this point?
*/
return ret;
}
return 0;
}
/**
* pinmux_disable() - disable the pinmux portions of a pin control handle
*/
void pinmux_disable(struct pinctrl *p)
{
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *ops = pctldev->desc->pmxops;
struct pinmux_group *grp;
list_for_each_entry(grp, &p->groups, node) {
ops->disable(pctldev, grp->func_selector,
grp->group_selector);
}
}
#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 func_selector = 0;
while (pmxops->list_functions(pctldev, func_selector) >= 0) {
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);
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++;
}
return 0;
}
static int pinmux_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
unsigned i, pin;
seq_puts(s, "Pinmux settings per pin\n");
seq_puts(s, "Format: pin (name): owner\n");
/* 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->owner &&
!strcmp(desc->owner, pinctrl_dev_get_name(pctldev)))
is_hog = true;
seq_printf(s, "pin %d (%s): %s%s\n", pin,
desc->name ? desc->name : "unnamed",
desc->owner ? desc->owner : "UNCLAIMED",
is_hog ? " (HOG)" : "");
}
return 0;
}
void pinmux_dbg_show(struct seq_file *s, struct pinctrl *p)
{
struct pinctrl_dev *pctldev = p->pctldev;
const struct pinmux_ops *pmxops;
const struct pinctrl_ops *pctlops;
struct pinmux_group *grp;
const char *sep = "";
pmxops = pctldev->desc->pmxops;
pctlops = pctldev->desc->pctlops;
seq_printf(s, " groups: [");
list_for_each_entry(grp, &p->groups, node) {
seq_printf(s, "%s%s (%u)=%s (%u)",
sep,
pctlops->get_group_name(pctldev,
grp->group_selector),
grp->group_selector,
pmxops->get_function_name(pctldev,
grp->func_selector),
grp->func_selector);
sep = ", ";
}
seq_printf(s, " ]");
}
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 */