forked from mirrors/linux
		
	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: Laurent Meunier <laurent.meunier@st.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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					 2 changed files with 238 additions and 0 deletions
				
			
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			@ -17,6 +17,7 @@
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#include <linux/slab.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/uaccess.h>
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#include <linux/pinctrl/machine.h>
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#include <linux/pinctrl/pinctrl.h>
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#include <linux/pinctrl/pinconf.h>
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			@ -574,6 +575,235 @@ static const struct file_operations pinconf_groups_ops = {
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	.release	= single_release,
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};
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#define MAX_NAME_LEN 15
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struct dbg_cfg {
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	enum pinctrl_map_type map_type;
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	char dev_name[MAX_NAME_LEN+1];
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	char state_name[MAX_NAME_LEN+1];
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	char pin_name[MAX_NAME_LEN+1];
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};
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/*
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 * Goal is to keep this structure as global in order to simply read the
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 * pinconf-config file after a write to check config is as expected
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 */
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static struct dbg_cfg pinconf_dbg_conf;
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/**
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 * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
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 * map, of the dev/pin/state that was last written to pinconf-config file.
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 * @s: string filled in  with config description
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 * @d: not used
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 */
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static int pinconf_dbg_config_print(struct seq_file *s, void *d)
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{
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	struct pinctrl_maps *maps_node;
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	const struct pinctrl_map *map;
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	struct pinctrl_dev *pctldev = NULL;
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	const struct pinconf_ops *confops = NULL;
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	const struct pinctrl_map_configs *configs;
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	struct dbg_cfg *dbg = &pinconf_dbg_conf;
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	int i, j;
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	bool found = false;
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	unsigned long config;
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	mutex_lock(&pinctrl_mutex);
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	/* Parse the pinctrl map and look for the elected pin/state */
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	for_each_maps(maps_node, i, map) {
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		if (map->type != dbg->map_type)
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			continue;
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		if (strcmp(map->dev_name, dbg->dev_name))
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			continue;
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		if (strcmp(map->name, dbg->state_name))
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			continue;
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		for (j = 0; j < map->data.configs.num_configs; j++) {
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			if (!strcmp(map->data.configs.group_or_pin,
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					dbg->pin_name)) {
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				/*
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				 * We found the right pin / state, read the
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				 * config and he pctldev for later use
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				 */
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				configs = &map->data.configs;
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				pctldev = get_pinctrl_dev_from_devname
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					(map->ctrl_dev_name);
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				found = true;
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				break;
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			}
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		}
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	}
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	if (!found) {
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		seq_printf(s, "No config found for dev/state/pin, expected:\n");
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		seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
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		seq_printf(s, "Searched state:%s\n", dbg->state_name);
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		seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
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		seq_printf(s, "Use: modify config_pin <devname> "\
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				"<state> <pinname> <value>\n");
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		goto exit;
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	}
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	config = *(configs->configs);
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	seq_printf(s, "Dev %s has config of %s in state %s: 0x%08lX\n",
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			dbg->dev_name, dbg->pin_name,
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			dbg->state_name, config);
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	if (pctldev)
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		confops = pctldev->desc->confops;
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	if (confops && confops->pin_config_config_dbg_show)
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		confops->pin_config_config_dbg_show(pctldev, s, config);
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exit:
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	mutex_unlock(&pinctrl_mutex);
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	return 0;
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}
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/**
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 * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
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 * map, of a dev/pin/state entry based on user entries to pinconf-config
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 * @user_buf: contains the modification request with expected format:
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 *     modify config_pin <devicename> <state> <pinname> <newvalue>
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 * modify is literal string, alternatives like add/delete not supported yet
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 * config_pin is literal, alternatives like config_mux not supported yet
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 * <devicename> <state> <pinname> are values that should match the pinctrl-maps
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 * <newvalue> reflects the new config and is driver dependant
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 */
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static int pinconf_dbg_config_write(struct file *file,
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	const char __user *user_buf, size_t count, loff_t *ppos)
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{
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	struct pinctrl_maps *maps_node;
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	const struct pinctrl_map *map;
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	struct pinctrl_dev *pctldev = NULL;
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	const struct pinconf_ops *confops = NULL;
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	struct dbg_cfg *dbg = &pinconf_dbg_conf;
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	const struct pinctrl_map_configs *configs;
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	char config[MAX_NAME_LEN+1];
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	bool found = false;
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	char buf[128];
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	char *b = &buf[0];
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	int buf_size;
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	char *token;
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	int i;
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	/* Get userspace string and assure termination */
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	buf_size = min(count, (sizeof(buf)-1));
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	if (copy_from_user(buf, user_buf, buf_size))
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		return -EFAULT;
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	buf[buf_size] = 0;
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	/*
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	 * need to parse entry and extract parameters:
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	 * modify configs_pin devicename state pinname newvalue
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	 */
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	/* Get arg: 'modify' */
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	token = strsep(&b, " ");
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	if (!token)
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		return -EINVAL;
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	if (strcmp(token, "modify"))
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		return -EINVAL;
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	/* Get arg type: "config_pin" type supported so far */
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	token = strsep(&b, " ");
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	if (!token)
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		return -EINVAL;
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	if (strcmp(token, "config_pin"))
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		return -EINVAL;
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	dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
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	/* get arg 'device_name' */
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	token = strsep(&b, " ");
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	if (token == NULL)
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		return -EINVAL;
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	if (strlen(token) >= MAX_NAME_LEN)
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		return -EINVAL;
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	strncpy(dbg->dev_name, token, MAX_NAME_LEN);
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	/* get arg 'state_name' */
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	token = strsep(&b, " ");
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	if (token == NULL)
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		return -EINVAL;
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	if (strlen(token) >= MAX_NAME_LEN)
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		return -EINVAL;
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	strncpy(dbg->state_name, token, MAX_NAME_LEN);
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	/* get arg 'pin_name' */
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	token = strsep(&b, " ");
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	if (token == NULL)
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		return -EINVAL;
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	if (strlen(token) >= MAX_NAME_LEN)
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		return -EINVAL;
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	strncpy(dbg->pin_name, token, MAX_NAME_LEN);
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	/* get new_value of config' */
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	token = strsep(&b, " ");
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	if (token == NULL)
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		return -EINVAL;
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	if (strlen(token) >= MAX_NAME_LEN)
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		return -EINVAL;
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	strncpy(config, token, MAX_NAME_LEN);
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	mutex_lock(&pinctrl_mutex);
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	/* Parse the pinctrl map and look for the selected dev/state/pin */
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	for_each_maps(maps_node, i, map) {
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		if (strcmp(map->dev_name, dbg->dev_name))
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			continue;
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		if (map->type != dbg->map_type)
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			continue;
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		if (strcmp(map->name, dbg->state_name))
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			continue;
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		/*  we found the right pin / state, so overwrite config */
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		if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
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			found = true;
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			pctldev = get_pinctrl_dev_from_devname(
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					map->ctrl_dev_name);
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			configs = &map->data.configs;
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			break;
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		}
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	}
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	if (!found) {
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		goto exit;
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		count = -EINVAL;
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	}
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	if (pctldev)
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		confops = pctldev->desc->confops;
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	if (confops && confops->pin_config_dbg_parse_modify) {
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		for (i = 0; i < configs->num_configs; i++) {
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			confops->pin_config_dbg_parse_modify(pctldev,
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						     config,
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						     &configs->configs[i]);
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		}
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	}
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exit:
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	mutex_unlock(&pinctrl_mutex);
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	return count;
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}
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static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
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{
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	return single_open(file, pinconf_dbg_config_print, inode->i_private);
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}
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static const struct file_operations pinconf_dbg_pinconfig_fops = {
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	.open = pinconf_dbg_config_open,
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	.write = pinconf_dbg_config_write,
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	.read = seq_read,
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	.llseek = seq_lseek,
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	.release = single_release,
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	.owner = THIS_MODULE,
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};
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void pinconf_init_device_debugfs(struct dentry *devroot,
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			 struct pinctrl_dev *pctldev)
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{
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			@ -581,6 +811,8 @@ void pinconf_init_device_debugfs(struct dentry *devroot,
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			    devroot, pctldev, &pinconf_pins_ops);
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	debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
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			    devroot, pctldev, &pinconf_groups_ops);
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	debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
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			    devroot, pctldev, &pinconf_dbg_pinconfig_fops);
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}
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#endif
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			@ -14,6 +14,8 @@
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#ifdef CONFIG_PINCONF
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#include <linux/pinctrl/machine.h>
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struct pinctrl_dev;
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struct seq_file;
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			@ -28,6 +30,7 @@ struct seq_file;
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 * @pin_config_set: configure an individual pin
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 * @pin_config_group_get: get configurations for an entire pin group
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 * @pin_config_group_set: configure all pins in a group
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 * @pin_config_group_dbg_set: optional debugfs to modify a pin configuration
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 * @pin_config_dbg_show: optional debugfs display hook that will provide
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 *	per-device info for a certain pin in debugfs
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 * @pin_config_group_dbg_show: optional debugfs display hook that will provide
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			@ -51,6 +54,9 @@ struct pinconf_ops {
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	int (*pin_config_group_set) (struct pinctrl_dev *pctldev,
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				     unsigned selector,
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				     unsigned long config);
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	int (*pin_config_dbg_parse_modify) (struct pinctrl_dev *pctldev,
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					   const char *arg,
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					   unsigned long *config);
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	void (*pin_config_dbg_show) (struct pinctrl_dev *pctldev,
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				     struct seq_file *s,
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				     unsigned offset);
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