[PATCH] pinctrl/pinconfig: add debug interface

Linus Walleij
2013-04-03T19:31:33Z

From: Laurent Meunier <laurent.meunier@st.com>

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.

Signed-off-by: Laurent Meunier <laurent.meunier@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/pinctrl/pinconf.c | 231 ++++++++++++++++++++++++++++++++++++++++
include/linux/pinctrl/pinconf.h | 4 +
2 files changed, 235 insertions(+)

diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c
index baee2cc..a95ac8d 100644
--- a/drivers/pinctrl/pinconf.c
+++ b/drivers/pinctrl/pinconf.c
@@ -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 +575,234 @@ static const struct file_operations pinconf_groups_ops = {
.release = single_release,
};

+/* 32bit read/write resources */
+#define MAX_NAME_LEN 15
+
+enum pinconf_dbg_request_type {
+ PINCONF_DBG_REQ_TYPE_INVALID,
+ PINCONF_DBG_REQ_TYPE_MODIFY,
+};
+
+struct dbg_cfg {
+ enum pinconf_dbg_request_type req_type;
+ 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];
+ char config[MAX_NAME_LEN+1];
+};
+
+static struct dbg_cfg pinconf_dbg_conf;
+
+/**
+ * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
+ * map, of a pin/state pair based on pinname and state that have been
+ * selected with the debugfs entries pinconf-name and pinconf-state
+ * @s: contains the 32bits config to be written
+ * @d: not used
+ */
+static int pinconf_dbg_config_print(struct seq_file *s, void *d)
+{
+ struct pinctrl_maps *maps_node;
+ struct pinctrl_map const *map;
+ struct pinctrl_dev *pctldev = NULL;
+ struct pinconf_ops const *confops = NULL;
+ int i, j;
+ bool found = false;
+ struct dbg_cfg *dbg = &pinconf_dbg_conf;
+ unsigned long config = 0;
+
+ 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 (strncmp(map->dev_name, dbg->dev_name, MAX_NAME_LEN) != 0)
+ continue;
+ if (strncmp(map->name, dbg->state_name, MAX_NAME_LEN) != 0)
+ continue;
+
+ for (j = 0; j < map->data.configs.num_configs; j++) {
+ if (0 == strncmp(map->data.configs.group_or_pin,
+ dbg->pin_name, MAX_NAME_LEN)) {
+ /*
+ * We found the right pin / state, read the
+ * config and store the pctldev
+ */
+ config = map->data.configs.configs[j];
+ pctldev = get_pinctrl_dev_from_devname
+ (map->ctrl_dev_name);
+ found = true;
+ break;
+ }
+ }
+ }
+
+ mutex_unlock(&pinctrl_mutex);
+
+ if (!found) {
+ seq_printf(s, "No config found for dev/state/pin, expected:\n");
+ seq_printf(s, "modify config_pins devname " \
+ "state pinname value\n");
+ }
+
+ 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);
+ return 0;
+}
+
+/**
+ * pinconf_dbg_config_write() - overwrite the pinctrl config in the pinctrl
+ * map, of a pin/state pair based on pinname and state that have been
+ * selected with the debugfs entries pinconf-name and pinconf-state
+ * @user_buf: contains 'modify configs_pin devicename state pinname newvalue'
+ */
+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;
+ struct pinctrl_map const *map;
+ struct pinctrl_dev *pctldev = NULL;
+ struct pinconf_ops const *confops = NULL;
+ struct dbg_cfg *dbg = &pinconf_dbg_conf;
+ bool found = false;
+ char buf[128];
+ char *b = &buf[0];
+ int buf_size;
+ char *token;
+ struct pinctrl_map_configs const *configs;
+ 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' */
+ if (!strncmp(b, "modify ", strlen("modify "))) {
+ dbg->req_type = PINCONF_DBG_REQ_TYPE_MODIFY;
+ b += strlen("modify ");
+ } else {
+ return -EINVAL;
+ }
+
+ /* Get arg type: "config_pin" type supported so far */
+ if (!strncmp(b, "config_pins ", strlen("config_pins "))) {
+ dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
+ b += strlen("config_pins ");
+ } else {
+ return -EINVAL;
+ }
+
+ /* get arg 'device_name' */
+ token = strsep(&b, " ");
+ if (token == NULL)
+ return -EINVAL;
+ if (strlen(token) < MAX_NAME_LEN)
+ sscanf(token, "%s", dbg->dev_name);
+ else
+ return -EINVAL;
+
+ /* get arg 'state_name' */
+ token = strsep(&b, " ");
+ if (token == NULL)
+ return -EINVAL;
+ if (strlen(token) < MAX_NAME_LEN)
+ sscanf(token, "%s", dbg->state_name);
+ else
+ return -EINVAL;
+
+ /* get arg 'pin_name' */
+ token = strsep(&b, " ");
+ if (token == NULL)
+ return -EINVAL;
+ if (strlen(token) < MAX_NAME_LEN)
+ sscanf(token, "%s", dbg->pin_name);
+ else
+ return -EINVAL;
+
+ /* get new_value of config' */
+ token = strsep(&b, " ");
+ if (token == NULL)
+ return -EINVAL;
+
+ if (strlen(token) < MAX_NAME_LEN)
+ sscanf(token, "%s", dbg->config);
+ else
+ return -EINVAL;
+
+ mutex_lock(&pinctrl_mutex);
+
+ /* Parse the pinctrl map and look for the selected dev/state/pin */
+ for_each_maps(maps_node, i, map) {
+ if (strncmp(map->dev_name, dbg->dev_name, MAX_NAME_LEN) != 0)
+ continue;
+ if (map->type != dbg->map_type)
+ continue;
+ if (strncmp(map->name, dbg->state_name, MAX_NAME_LEN) != 0)
+ continue;
+
+ /* we found the right pin / state, so overwrite config */
+ if (strncmp(map->data.configs.group_or_pin,
+ dbg->pin_name, MAX_NAME_LEN) == 0) {
+
+ found = true;
+ pctldev = get_pinctrl_dev_from_devname(
+ map->ctrl_dev_name);
+ configs = &map->data.configs;
+ break;
+ }
+ }
+
+ mutex_unlock(&pinctrl_mutex);
+
+ if (!found)
+ return -EINVAL;
+
+ if (pctldev)
+ confops = pctldev->desc->confops;
+
+ if (confops && confops->pin_config_dbg_set) {
+ for (i = 0; i < configs->num_configs; i++) {
+ confops->pin_config_dbg_set(pctldev,
+ dbg->config,
+ configs->configs[i]);
+ }
+ }
+
+ 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 +810,8 @@ 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
diff --git a/include/linux/pinctrl/pinconf.h b/include/linux/pinctrl/pinconf.h
index e7a7201..2cc8d2c 100644
--- a/include/linux/pinctrl/pinconf.h
+++ b/include/linux/pinctrl/pinconf.h
@@ -28,6 +28,7 @@ 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 +52,9 @@ struct pinconf_ops {
int (*pin_config_group_set) (struct pinctrl_dev *pctldev,
unsigned selector,
unsigned long config);
+ int (*pin_config_dbg_set) (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);
--
1.7.11.3