Commit f07512e6 authored by Laurent Meunier's avatar Laurent Meunier Committed by Linus Walleij
Browse files

pinctrl/pinconfig: add debug interface 



This update adds a debugfs interface to modify a pin configuration
for a given state in the pinctrl map. This allows to modify the
configuration for a non-active state, typically sleep state.
This configuration is not applied right away, but only when the state
will be entered.

This solution is mandated for us by HW validation: in order
to test and verify several pin configurations during sleep without
recompiling the software.

Change log in this patch set;
Take into account latest feedback from Stephen Warren:
- stale comments update
- improved code efficiency and readibility
- limit size of global variable pinconf_dbg_conf
- remove req_type as it can easily be added later when
add/delete requests support is implemented

Signed-off-by: default avatarLaurent Meunier <laurent.meunier@st.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 06b62d82

drivers/pinctrl/pinconf.c

+232 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/slab.h>

#include <linux/debugfs.h>

#include <linux/seq_file.h>

#include <linux/uaccess.h>

#include <linux/pinctrl/machine.h>

#include <linux/pinctrl/pinctrl.h>

#include <linux/pinctrl/pinconf.h>
@@ -574,6 +575,235 @@ static const struct file_operations pinconf_groups_ops = { 
	.release	= single_release,

};



#define MAX_NAME_LEN 15



struct dbg_cfg {

	enum pinctrl_map_type map_type;

	char dev_name[MAX_NAME_LEN+1];

	char state_name[MAX_NAME_LEN+1];

	char pin_name[MAX_NAME_LEN+1];

};



/*

 * Goal is to keep this structure as global in order to simply read the

 * pinconf-config file after a write to check config is as expected

 */

static struct dbg_cfg pinconf_dbg_conf;



/**

 * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl

 * map, of the dev/pin/state that was last written to pinconf-config file.

 * @s: string filled in  with config description

 * @d: not used

 */

static int pinconf_dbg_config_print(struct seq_file *s, void *d)

{

	struct pinctrl_maps *maps_node;

	const struct pinctrl_map *map;

	struct pinctrl_dev *pctldev = NULL;

	const struct pinconf_ops *confops = NULL;

	const struct pinctrl_map_configs *configs;

	struct dbg_cfg *dbg = &pinconf_dbg_conf;

	int i, j;

	bool found = false;

	unsigned long config;



	mutex_lock(&pinctrl_mutex);



	/* Parse the pinctrl map and look for the elected pin/state */

	for_each_maps(maps_node, i, map) {

		if (map->type != dbg->map_type)

			continue;

		if (strcmp(map->dev_name, dbg->dev_name))

			continue;

		if (strcmp(map->name, dbg->state_name))

			continue;



		for (j = 0; j < map->data.configs.num_configs; j++) {

			if (!strcmp(map->data.configs.group_or_pin,

					dbg->pin_name)) {

				/*

				 * We found the right pin / state, read the

				 * config and he pctldev for later use

				 */

				configs = &map->data.configs;

				pctldev = get_pinctrl_dev_from_devname

					(map->ctrl_dev_name);

				found = true;

				break;

			}

		}

	}



	if (!found) {

		seq_printf(s, "No config found for dev/state/pin, expected:\n");

		seq_printf(s, "Searched dev:%s\n", dbg->dev_name);

		seq_printf(s, "Searched state:%s\n", dbg->state_name);

		seq_printf(s, "Searched pin:%s\n", dbg->pin_name);

		seq_printf(s, "Use: modify config_pin <devname> "\

				"<state> <pinname> <value>\n");

		goto exit;

	}



	config = *(configs->configs);

	seq_printf(s, "Dev %s has config of %s in state %s: 0x%08lX\n",

			dbg->dev_name, dbg->pin_name,

			dbg->state_name, config);



	if (pctldev)

		confops = pctldev->desc->confops;



	if (confops && confops->pin_config_config_dbg_show)

		confops->pin_config_config_dbg_show(pctldev, s, config);



exit:

	mutex_unlock(&pinctrl_mutex);



	return 0;

}



/**

 * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl

 * map, of a dev/pin/state entry based on user entries to pinconf-config

 * @user_buf: contains the modification request with expected format:

 *     modify config_pin <devicename> <state> <pinname> <newvalue>

 * modify is literal string, alternatives like add/delete not supported yet

 * config_pin is literal, alternatives like config_mux not supported yet

 * <devicename> <state> <pinname> are values that should match the pinctrl-maps

 * <newvalue> reflects the new config and is driver dependant

 */

static int pinconf_dbg_config_write(struct file *file,

	const char __user *user_buf, size_t count, loff_t *ppos)

{

	struct pinctrl_maps *maps_node;

	const struct pinctrl_map *map;

	struct pinctrl_dev *pctldev = NULL;

	const struct pinconf_ops *confops = NULL;

	struct dbg_cfg *dbg = &pinconf_dbg_conf;

	const struct pinctrl_map_configs *configs;

	char config[MAX_NAME_LEN+1];

	bool found = false;

	char buf[128];

	char *b = &buf[0];

	int buf_size;

	char *token;

	int i;



	/* Get userspace string and assure termination */

	buf_size = min(count, (sizeof(buf)-1));

	if (copy_from_user(buf, user_buf, buf_size))

		return -EFAULT;

	buf[buf_size] = 0;



	/*

	 * need to parse entry and extract parameters:

	 * modify configs_pin devicename state pinname newvalue

	 */



	/* Get arg: 'modify' */

	token = strsep(&b, " ");

	if (!token)

		return -EINVAL;

	if (strcmp(token, "modify"))

		return -EINVAL;



	/* Get arg type: "config_pin" type supported so far */

	token = strsep(&b, " ");

	if (!token)

		return -EINVAL;

	if (strcmp(token, "config_pin"))

		return -EINVAL;

	dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;



	/* get arg 'device_name' */

	token = strsep(&b, " ");

	if (token == NULL)

		return -EINVAL;

	if (strlen(token) >= MAX_NAME_LEN)

		return -EINVAL;

	strncpy(dbg->dev_name, token, MAX_NAME_LEN);



	/* get arg 'state_name' */

	token = strsep(&b, " ");

	if (token == NULL)

		return -EINVAL;

	if (strlen(token) >= MAX_NAME_LEN)

		return -EINVAL;

	strncpy(dbg->state_name, token, MAX_NAME_LEN);



	/* get arg 'pin_name' */

	token = strsep(&b, " ");

	if (token == NULL)

		return -EINVAL;

	if (strlen(token) >= MAX_NAME_LEN)

		return -EINVAL;

	strncpy(dbg->pin_name, token, MAX_NAME_LEN);



	/* get new_value of config' */

	token = strsep(&b, " ");

	if (token == NULL)

		return -EINVAL;

	if (strlen(token) >= MAX_NAME_LEN)

		return -EINVAL;

	strncpy(config, token, MAX_NAME_LEN);



	mutex_lock(&pinctrl_mutex);



	/* Parse the pinctrl map and look for the selected dev/state/pin */

	for_each_maps(maps_node, i, map) {

		if (strcmp(map->dev_name, dbg->dev_name))

			continue;

		if (map->type != dbg->map_type)

			continue;

		if (strcmp(map->name, dbg->state_name))

			continue;



		/*  we found the right pin / state, so overwrite config */

		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {

			found = true;

			pctldev = get_pinctrl_dev_from_devname(

					map->ctrl_dev_name);

			configs = &map->data.configs;

			break;

		}

	}



	if (!found) {

		goto exit;

		count = -EINVAL;

	}



	if (pctldev)

		confops = pctldev->desc->confops;



	if (confops && confops->pin_config_dbg_parse_modify) {

		for (i = 0; i < configs->num_configs; i++) {

			confops->pin_config_dbg_parse_modify(pctldev,

						     config,

						     &configs->configs[i]);

		}

	}



exit:

	mutex_unlock(&pinctrl_mutex);



	return count;

}



static int pinconf_dbg_config_open(struct inode *inode, struct file *file)

{

	return single_open(file, pinconf_dbg_config_print, inode->i_private);

}



static const struct file_operations pinconf_dbg_pinconfig_fops = {

	.open = pinconf_dbg_config_open,

	.write = pinconf_dbg_config_write,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

	.owner = THIS_MODULE,

};



void pinconf_init_device_debugfs(struct dentry *devroot,

			 struct pinctrl_dev *pctldev)

{
@@ -581,6 +811,8 @@ void pinconf_init_device_debugfs(struct dentry *devroot, 
			    devroot, pctldev, &pinconf_pins_ops);

	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,

			    devroot, pctldev, &pinconf_groups_ops);

	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),

			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);

}



#endif

include/linux/pinctrl/pinconf.h

+6 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ 


#ifdef CONFIG_PINCONF



#include <linux/pinctrl/machine.h>



struct pinctrl_dev;

struct seq_file;
@@ -28,6 +30,7 @@ struct seq_file; 
 * @pin_config_set: configure an individual pin

 * @pin_config_group_get: get configurations for an entire pin group

 * @pin_config_group_set: configure all pins in a group

 * @pin_config_group_dbg_set: optional debugfs to modify a pin configuration

 * @pin_config_dbg_show: optional debugfs display hook that will provide

 *	per-device info for a certain pin in debugfs

 * @pin_config_group_dbg_show: optional debugfs display hook that will provide
@@ -51,6 +54,9 @@ struct pinconf_ops { 
	int (*pin_config_group_set) (struct pinctrl_dev *pctldev,

				     unsigned selector,

				     unsigned long config);

	int (*pin_config_dbg_parse_modify) (struct pinctrl_dev *pctldev,

					   const char *arg,

					   unsigned long *config);

	void (*pin_config_dbg_show) (struct pinctrl_dev *pctldev,

				     struct seq_file *s,

				     unsigned offset);

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