linux/drivers/pinctrl/pinconf.c
Tony Lindgren b9130b776e pinctrl: add checks for empty function names
This is needed as otherwise we can get the following when
dealing with buggy data in a pinmux driver for
pinmux_search_function:

Unable to handle kernel NULL pointer dereference at virtual
address 00000000
...
PC is at strcmp+0xc/0x34
LR is at pinmux_get+0x350/0x8f4
...

As we need pctldev initialized to call ops->list_functions,
let's initialize it before check_ops calls and pass the
pctldev to the check_ops functions. Do this for both pinmux
and pinconf check_ops functions.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-01-26 14:13:11 +01:00

329 lines
8.3 KiB
C

/*
* Core driver for the pin config portions of the pin control subsystem
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#define pr_fmt(fmt) "pinconfig core: " fmt
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf.h>
#include "core.h"
#include "pinconf.h"
int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
unsigned long *config)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
if (!ops || !ops->pin_config_get) {
dev_err(pctldev->dev, "cannot get pin configuration, missing "
"pin_config_get() function in driver\n");
return -EINVAL;
}
return ops->pin_config_get(pctldev, pin, config);
}
/**
* pin_config_get() - get the configuration of a single pin parameter
* @dev_name: name of the pin controller device for this pin
* @name: name of the pin to get the config for
* @config: the config pointed to by this argument will be filled in with the
* current pin state, it can be used directly by drivers as a numeral, or
* it can be dereferenced to any struct.
*/
int pin_config_get(const char *dev_name, const char *name,
unsigned long *config)
{
struct pinctrl_dev *pctldev;
int pin;
pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
if (!pctldev)
return -EINVAL;
pin = pin_get_from_name(pctldev, name);
if (pin < 0)
return pin;
return pin_config_get_for_pin(pctldev, pin, config);
}
EXPORT_SYMBOL(pin_config_get);
int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
unsigned long config)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
int ret;
if (!ops || !ops->pin_config_set) {
dev_err(pctldev->dev, "cannot configure pin, missing "
"config function in driver\n");
return -EINVAL;
}
ret = ops->pin_config_set(pctldev, pin, config);
if (ret) {
dev_err(pctldev->dev,
"unable to set pin configuration on pin %d\n", pin);
return ret;
}
return 0;
}
/**
* pin_config_set() - set the configuration of a single pin parameter
* @dev_name: name of pin controller device for this pin
* @name: name of the pin to set the config for
* @config: the config in this argument will contain the desired pin state, it
* can be used directly by drivers as a numeral, or it can be dereferenced
* to any struct.
*/
int pin_config_set(const char *dev_name, const char *name,
unsigned long config)
{
struct pinctrl_dev *pctldev;
int pin;
pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
if (!pctldev)
return -EINVAL;
pin = pin_get_from_name(pctldev, name);
if (pin < 0)
return pin;
return pin_config_set_for_pin(pctldev, pin, config);
}
EXPORT_SYMBOL(pin_config_set);
int pin_config_group_get(const char *dev_name, const char *pin_group,
unsigned long *config)
{
struct pinctrl_dev *pctldev;
const struct pinconf_ops *ops;
int selector;
pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
if (!pctldev)
return -EINVAL;
ops = pctldev->desc->confops;
if (!ops || !ops->pin_config_group_get) {
dev_err(pctldev->dev, "cannot get configuration for pin "
"group, missing group config get function in "
"driver\n");
return -EINVAL;
}
selector = pinctrl_get_group_selector(pctldev, pin_group);
if (selector < 0)
return selector;
return ops->pin_config_group_get(pctldev, selector, config);
}
EXPORT_SYMBOL(pin_config_group_get);
int pin_config_group_set(const char *dev_name, const char *pin_group,
unsigned long config)
{
struct pinctrl_dev *pctldev;
const struct pinconf_ops *ops;
const struct pinctrl_ops *pctlops;
int selector;
const unsigned *pins;
unsigned num_pins;
int ret;
int i;
pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
if (!pctldev)
return -EINVAL;
ops = pctldev->desc->confops;
pctlops = pctldev->desc->pctlops;
if (!ops || (!ops->pin_config_group_set && !ops->pin_config_set)) {
dev_err(pctldev->dev, "cannot configure pin group, missing "
"config function in driver\n");
return -EINVAL;
}
selector = pinctrl_get_group_selector(pctldev, pin_group);
if (selector < 0)
return selector;
ret = pctlops->get_group_pins(pctldev, selector, &pins, &num_pins);
if (ret) {
dev_err(pctldev->dev, "cannot configure pin group, error "
"getting pins\n");
return ret;
}
/*
* If the pin controller supports handling entire groups we use that
* capability.
*/
if (ops->pin_config_group_set) {
ret = ops->pin_config_group_set(pctldev, selector, config);
/*
* If the pin controller prefer that a certain group be handled
* pin-by-pin as well, it returns -EAGAIN.
*/
if (ret != -EAGAIN)
return ret;
}
/*
* If the controller cannot handle entire groups, we configure each pin
* individually.
*/
if (!ops->pin_config_set)
return 0;
for (i = 0; i < num_pins; i++) {
ret = ops->pin_config_set(pctldev, pins[i], config);
if (ret < 0)
return ret;
}
return 0;
}
EXPORT_SYMBOL(pin_config_group_set);
int pinconf_check_ops(struct pinctrl_dev *pctldev)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
/* We must be able to read out pin status */
if (!ops->pin_config_get && !ops->pin_config_group_get)
return -EINVAL;
/* We have to be able to config the pins in SOME way */
if (!ops->pin_config_set && !ops->pin_config_group_set)
return -EINVAL;
return 0;
}
#ifdef CONFIG_DEBUG_FS
static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
struct seq_file *s, int pin)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
if (ops && ops->pin_config_dbg_show)
ops->pin_config_dbg_show(pctldev, s, pin);
}
static int pinconf_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
unsigned i, pin;
seq_puts(s, "Pin config settings per pin\n");
seq_puts(s, "Format: pin (name): pinmux setting array\n");
/* The pin number can be retrived from the pin controller descriptor */
for (i = 0; i < pctldev->desc->npins; i++) {
struct pin_desc *desc;
pin = pctldev->desc->pins[i].number;
desc = pin_desc_get(pctldev, pin);
/* Skip if we cannot search the pin */
if (desc == NULL)
continue;
seq_printf(s, "pin %d (%s):", pin,
desc->name ? desc->name : "unnamed");
pinconf_dump_pin(pctldev, s, pin);
seq_printf(s, "\n");
}
return 0;
}
static void pinconf_dump_group(struct pinctrl_dev *pctldev,
struct seq_file *s, unsigned selector,
const char *gname)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
if (ops && ops->pin_config_group_dbg_show)
ops->pin_config_group_dbg_show(pctldev, s, selector);
}
static int pinconf_groups_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
const struct pinconf_ops *ops = pctldev->desc->confops;
unsigned selector = 0;
if (!ops || !ops->pin_config_group_get)
return 0;
seq_puts(s, "Pin config settings per pin group\n");
seq_puts(s, "Format: group (name): pinmux setting array\n");
while (pctlops->list_groups(pctldev, selector) >= 0) {
const char *gname = pctlops->get_group_name(pctldev, selector);
seq_printf(s, "%u (%s):", selector, gname);
pinconf_dump_group(pctldev, s, selector, gname);
selector++;
}
return 0;
}
static int pinconf_pins_open(struct inode *inode, struct file *file)
{
return single_open(file, pinconf_pins_show, inode->i_private);
}
static int pinconf_groups_open(struct inode *inode, struct file *file)
{
return single_open(file, pinconf_groups_show, inode->i_private);
}
static const struct file_operations pinconf_pins_ops = {
.open = pinconf_pins_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static const struct file_operations pinconf_groups_ops = {
.open = pinconf_groups_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
void pinconf_init_device_debugfs(struct dentry *devroot,
struct pinctrl_dev *pctldev)
{
debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
devroot, pctldev, &pinconf_pins_ops);
debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
devroot, pctldev, &pinconf_groups_ops);
}
#endif