From: Laurent Meunier <laurent.meun...@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. 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.meun...@st.com> Signed-off-by: Linus Walleij <linus.wall...@linaro.org> --- drivers/pinctrl/pinconf.c | 232 ++++++++++++++++++++++++++++++++++++++++ include/linux/pinctrl/pinconf.h | 6 ++ 2 files changed, 238 insertions(+) diff --git a/drivers/pinctrl/pinconf.c b/drivers/pinctrl/pinconf.c index baee2cc..1b6047d 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 +575,235 @@ 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 diff --git a/include/linux/pinctrl/pinconf.h b/include/linux/pinctrl/pinconf.h index e7a7201..1ad4f31 100644 --- a/include/linux/pinctrl/pinconf.h +++ b/include/linux/pinctrl/pinconf.h @@ -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); -- 1.7.11.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/