diff options
author | Stephen Warren <swarren@nvidia.com> | 2012-03-02 20:05:47 (GMT) |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2012-03-05 10:22:59 (GMT) |
commit | 6e5e959dde0d92d177f035652aeaa77f9330c9c6 (patch) | |
tree | c2d874df6a1c591b558a17591a1c8fbc2ba7a1e1 /drivers/pinctrl | |
parent | 0e3db173e2b9fd3b82246516e72c17763eb5f98d (diff) | |
download | linux-6e5e959dde0d92d177f035652aeaa77f9330c9c6.tar.xz |
pinctrl: API changes to support multiple states per device
The API model is changed from:
p = pinctrl_get(dev, "state1");
pinctrl_enable(p);
...
pinctrl_disable(p);
pinctrl_put(p);
p = pinctrl_get(dev, "state2");
pinctrl_enable(p);
...
pinctrl_disable(p);
pinctrl_put(p);
to this:
p = pinctrl_get(dev);
s1 = pinctrl_lookup_state(p, "state1");
s2 = pinctrl_lookup_state(p, "state2");
pinctrl_select_state(p, s1);
...
pinctrl_select_state(p, s2);
...
pinctrl_put(p);
This allows devices to directly transition between states without
disabling the pin controller programming and put()/get()ing the
configuration data each time. This model will also better suit pinconf
programming, which doesn't have a concept of "disable".
The special-case hogging feature of pin controllers is re-written to use
the regular APIs instead of special-case code. Hence, the pinmux-hogs
debugfs file is removed; see the top-level pinctrl-handles files for
equivalent data.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl')
-rw-r--r-- | drivers/pinctrl/core.c | 363 | ||||
-rw-r--r-- | drivers/pinctrl/core.h | 23 |
2 files changed, 237 insertions, 149 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 535f8d5..c6f3ca3 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -458,25 +458,98 @@ int pinctrl_gpio_direction_output(unsigned gpio) } EXPORT_SYMBOL_GPL(pinctrl_gpio_direction_output); -static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name) +static struct pinctrl_state *find_state(struct pinctrl *p, + const char *name) { - struct pinctrl_dev *pctldev; - const char *devname; - struct pinctrl *p; - unsigned num_maps = 0; - int ret; - struct pinctrl_maps *maps_node; - int i; - struct pinctrl_map const *map; + struct pinctrl_state *state; + + list_for_each_entry(state, &p->states, node) + if (!strcmp(state->name, name)) + return state; + + return NULL; +} + +static struct pinctrl_state *create_state(struct pinctrl *p, + const char *name) +{ + struct pinctrl_state *state; + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (state == NULL) { + dev_err(p->dev, + "failed to alloc struct pinctrl_state\n"); + return ERR_PTR(-ENOMEM); + } + + state->name = name; + INIT_LIST_HEAD(&state->settings); + + list_add_tail(&state->node, &p->states); + + return state; +} + +static int add_setting(struct pinctrl *p, struct pinctrl_map const *map) +{ + struct pinctrl_state *state; struct pinctrl_setting *setting; + int ret; - /* We must have both a dev and state name */ - if (WARN_ON(!dev || !name)) - return ERR_PTR(-EINVAL); + state = find_state(p, map->name); + if (!state) + state = create_state(p, map->name); + if (IS_ERR(state)) + return PTR_ERR(state); - devname = dev_name(dev); + setting = kzalloc(sizeof(*setting), GFP_KERNEL); + if (setting == NULL) { + dev_err(p->dev, + "failed to alloc struct pinctrl_setting\n"); + return -ENOMEM; + } - dev_dbg(dev, "pinctrl_get() for device %s state %s\n", devname, name); + setting->pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name); + if (setting->pctldev == NULL) { + dev_err(p->dev, "unknown pinctrl device %s in map entry", + map->ctrl_dev_name); + kfree(setting); + /* Eventually, this should trigger deferred probe */ + return -ENODEV; + } + + ret = pinmux_map_to_setting(map, setting); + if (ret < 0) { + kfree(setting); + return ret; + } + + list_add_tail(&setting->node, &state->settings); + + return 0; +} + +static struct pinctrl *find_pinctrl(struct device *dev) +{ + struct pinctrl *p; + + list_for_each_entry(p, &pinctrldev_list, node) + if (p->dev == dev) + return p; + + return NULL; +} + +static void pinctrl_put_locked(struct pinctrl *p, bool inlist); + +static struct pinctrl *create_pinctrl(struct device *dev) +{ + struct pinctrl *p; + const char *devname; + struct pinctrl_maps *maps_node; + int i; + struct pinctrl_map const *map; + int ret; /* * create the state cookie holder struct pinctrl for each @@ -489,8 +562,9 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name) return ERR_PTR(-ENOMEM); } p->dev = dev; - p->state = name; - INIT_LIST_HEAD(&p->settings); + INIT_LIST_HEAD(&p->states); + + devname = dev_name(dev); /* Iterate over the pin control maps to locate the right ones */ for_each_maps(maps_node, i, map) { @@ -498,183 +572,179 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev, const char *name) if (strcmp(map->dev_name, devname)) continue; - /* State name must be the one we're looking for */ - if (strcmp(map->name, name)) - continue; - - /* - * Try to find the pctldev given in the map - */ - pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name); - if (!pctldev) { - dev_err(dev, "unknown pinctrl device %s in map entry", - map->ctrl_dev_name); - /* Eventually, this should trigger deferred probe */ - ret = -ENODEV; - goto error; - } - - dev_dbg(dev, "in map, found pctldev %s to handle function %s", - dev_name(pctldev->dev), map->function); - - setting = kzalloc(sizeof(*setting), GFP_KERNEL); - if (setting == NULL) { - dev_err(dev, - "failed to alloc struct pinctrl_setting\n"); - ret = -ENOMEM; - goto error; + ret = add_setting(p, map); + if (ret < 0) { + pinctrl_put_locked(p, false); + return ERR_PTR(ret); } - - setting->pctldev = pctldev; - ret = pinmux_map_to_setting(map, setting); - if (ret < 0) - goto error; - - list_add_tail(&setting->node, &p->settings); - - num_maps++; } - /* - * This may be perfectly legitimate. An IP block may get re-used - * across SoCs. Not all of those SoCs may need pinmux settings for the - * IP block, e.g. if one SoC dedicates pins to that function but - * another doesn't. The driver won't know this, and will always - * attempt to set up the pinmux. The mapping table defines whether any - * HW programming is actually needed. - */ - if (!num_maps) - dev_info(dev, "zero maps found for mapping %s\n", name); - - dev_dbg(dev, "found %u maps for device %s state %s\n", - num_maps, devname, name ? name : "(undefined)"); - /* Add the pinmux to the global list */ list_add_tail(&p->node, &pinctrl_list); return p; +} -error: - list_for_each_entry(setting, &p->settings, node) - pinmux_free_setting(setting); +static struct pinctrl *pinctrl_get_locked(struct device *dev) +{ + struct pinctrl *p; - kfree(p); + if (WARN_ON(!dev)) + return ERR_PTR(-EINVAL); + + p = find_pinctrl(dev); + if (p != NULL) + return ERR_PTR(-EBUSY); - return ERR_PTR(ret); + p = create_pinctrl(dev); + if (IS_ERR(p)) + return p; + + return p; } /** - * pinctrl_get() - retrieves the pin controller handle for a certain device - * @dev: the device to get the pin controller handle for - * @name: an optional specific control mapping name or NULL, the name is only - * needed if you want to have more than one mapping per device, or if you - * need an anonymous pin control (not tied to any specific device) + * pinctrl_get() - retrieves the pinctrl handle for a device + * @dev: the device to obtain the handle for */ -struct pinctrl *pinctrl_get(struct device *dev, const char *name) +struct pinctrl *pinctrl_get(struct device *dev) { struct pinctrl *p; mutex_lock(&pinctrl_mutex); - p = pinctrl_get_locked(dev, name); + p = pinctrl_get_locked(dev); mutex_unlock(&pinctrl_mutex); return p; } EXPORT_SYMBOL_GPL(pinctrl_get); -static void pinctrl_put_locked(struct pinctrl *p) +static void pinctrl_put_locked(struct pinctrl *p, bool inlist) { - struct pinctrl_setting *setting, *n; - - if (p == NULL) - return; - - if (p->usecount) - pr_warn("releasing pin control handle with active users!\n"); - list_for_each_entry_safe(setting, n, &p->settings, node) { - pinmux_free_setting(setting); - list_del(&setting->node); - kfree(setting); + struct pinctrl_state *state, *n1; + struct pinctrl_setting *setting, *n2; + + list_for_each_entry_safe(state, n1, &p->states, node) { + list_for_each_entry_safe(setting, n2, &state->settings, node) { + if (state == p->state) + pinmux_disable_setting(setting); + pinmux_free_setting(setting); + list_del(&setting->node); + kfree(setting); + } + list_del(&state->node); + kfree(state); } - /* Remove from list */ - list_del(&p->node); - + if (inlist) + list_del(&p->node); kfree(p); } /** - * pinctrl_put() - release a previously claimed pin control handle - * @p: a pin control handle previously claimed by pinctrl_get() + * pinctrl_put() - release a previously claimed pinctrl handle + * @p: the pinctrl handle to release */ void pinctrl_put(struct pinctrl *p) { mutex_lock(&pinctrl_mutex); - pinctrl_put(p); + pinctrl_put_locked(p, true); mutex_unlock(&pinctrl_mutex); } EXPORT_SYMBOL_GPL(pinctrl_put); -static int pinctrl_enable_locked(struct pinctrl *p) +static struct pinctrl_state *pinctrl_lookup_state_locked(struct pinctrl *p, + const char *name) { - struct pinctrl_setting *setting; - int ret; + struct pinctrl_state *state; - if (p == NULL) - return -EINVAL; + state = find_state(p, name); + if (!state) + return ERR_PTR(-ENODEV); - if (p->usecount++ == 0) { - list_for_each_entry(setting, &p->settings, node) { - ret = pinmux_enable_setting(setting); - if (ret < 0) { - /* FIXME: Difficult to return to prev state */ - p->usecount--; - return ret; - } - } - } - - return 0; + return state; } /** - * pinctrl_enable() - enable a certain pin controller setting - * @p: the pin control handle to enable, previously claimed by pinctrl_get() + * pinctrl_lookup_state() - retrieves a state handle from a pinctrl handle + * @p: the pinctrl handle to retrieve the state from + * @name: the state name to retrieve */ -int pinctrl_enable(struct pinctrl *p) +struct pinctrl_state *pinctrl_lookup_state(struct pinctrl *p, const char *name) { - int ret; + struct pinctrl_state *s; + mutex_lock(&pinctrl_mutex); - ret = pinctrl_enable_locked(p); + s = pinctrl_lookup_state_locked(p, name); mutex_unlock(&pinctrl_mutex); - return ret; + + return s; } -EXPORT_SYMBOL_GPL(pinctrl_enable); +EXPORT_SYMBOL_GPL(pinctrl_lookup_state); -static void pinctrl_disable_locked(struct pinctrl *p) +static int pinctrl_select_state_locked(struct pinctrl *p, + struct pinctrl_state *state) { - struct pinctrl_setting *setting; + struct pinctrl_setting *setting, *setting2; + int ret; - if (p == NULL) - return; + if (p->state == state) + return 0; - if (--p->usecount == 0) { - list_for_each_entry(setting, &p->settings, node) - pinmux_disable_setting(setting); + if (p->state) { + /* + * The set of groups with a mux configuration in the old state + * may not be identical to the set of groups with a mux setting + * in the new state. While this might be unusual, it's entirely + * possible for the "user"-supplied mapping table to be written + * that way. For each group that was configured in the old state + * but not in the new state, this code puts that group into a + * safe/disabled state. + */ + list_for_each_entry(setting, &p->state->settings, node) { + bool found = false; + list_for_each_entry(setting2, &state->settings, node) { + if (setting2->group_selector == + setting->group_selector) { + found = true; + break; + } + } + if (!found) + pinmux_disable_setting(setting); + } + } + + p->state = state; + + /* Apply all the settings for the new state */ + list_for_each_entry(setting, &state->settings, node) { + ret = pinmux_enable_setting(setting); + if (ret < 0) { + /* FIXME: Difficult to return to prev state */ + return ret; + } } + + return 0; } /** - * pinctrl_disable() - disable a certain pin control setting - * @p: the pin control handle to disable, previously claimed by pinctrl_get() + * pinctrl_select() - select/activate/program a pinctrl state to HW + * @p: the pinctrl handle for the device that requests configuratio + * @state: the state handle to select/activate/program */ -void pinctrl_disable(struct pinctrl *p) +int pinctrl_select_state(struct pinctrl *p, struct pinctrl_state *state) { + int ret; + mutex_lock(&pinctrl_mutex); - pinctrl_disable_locked(p); + ret = pinctrl_select_state_locked(p, state); mutex_unlock(&pinctrl_mutex); + + return ret; } -EXPORT_SYMBOL_GPL(pinctrl_disable); +EXPORT_SYMBOL_GPL(pinctrl_select_state); /** * pinctrl_register_mappings() - register a set of pin controller mappings @@ -891,6 +961,7 @@ static int pinctrl_maps_show(struct seq_file *s, void *what) static int pinctrl_show(struct seq_file *s, void *what) { struct pinctrl *p; + struct pinctrl_state *state; struct pinctrl_setting *setting; seq_puts(s, "Requested pin control handlers their pinmux maps:\n"); @@ -898,12 +969,17 @@ static int pinctrl_show(struct seq_file *s, void *what) mutex_lock(&pinctrl_mutex); list_for_each_entry(p, &pinctrl_list, node) { - seq_printf(s, "device: %s state: %s users: %u\n", - dev_name(p->dev), p->state, p->usecount); + seq_printf(s, "device: %s current state: %s\n", + dev_name(p->dev), + p->state ? p->state->name : "none"); + + list_for_each_entry(state, &p->states, node) { + seq_printf(s, " state: %s\n", state->name); - list_for_each_entry(setting, &p->settings, node) { - seq_printf(s, " "); - pinmux_dbg_show(s, setting); + list_for_each_entry(setting, &state->settings, node) { + seq_printf(s, " "); + pinmux_dbg_show(s, setting); + } } } @@ -1113,9 +1189,14 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc, list_add_tail(&pctldev->node, &pinctrldev_list); - pctldev->p = pinctrl_get_locked(pctldev->dev, PINCTRL_STATE_DEFAULT); - if (!IS_ERR(pctldev->p)) - pinctrl_enable_locked(pctldev->p); + pctldev->p = pinctrl_get_locked(pctldev->dev); + if (!IS_ERR(pctldev->p)) { + struct pinctrl_state *s = + pinctrl_lookup_state_locked(pctldev->p, + PINCTRL_STATE_DEFAULT); + if (!IS_ERR(s)) + pinctrl_select_state_locked(pctldev->p, s); + } mutex_unlock(&pinctrl_mutex); @@ -1144,10 +1225,8 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev) mutex_lock(&pinctrl_mutex); - if (!IS_ERR(pctldev->p)) { - pinctrl_disable_locked(pctldev->p); - pinctrl_put_locked(pctldev->p); - } + if (!IS_ERR(pctldev->p)) + pinctrl_put_locked(pctldev->p, true); /* TODO: check that no pinmuxes are still active? */ list_del(&pctldev->node); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index 0bc52ec..5691d31 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -49,22 +49,31 @@ struct pinctrl_dev { * struct pinctrl - per-device pin control state holder * @node: global list node * @dev: the device using this pin control handle - * @state: the state name passed to pinctrl_get() - * @usecount: the number of active users of this pin controller setting, used - * to keep track of nested use cases - * @settings: a list of settings for this device/state + * @states: a list of states for this device + * @state: the current state */ struct pinctrl { struct list_head node; struct device *dev; - const char *state; - unsigned usecount; + struct list_head states; + struct pinctrl_state *state; +}; + +/** + * struct pinctrl_state - a pinctrl state for a device + * @node: list not for struct pinctrl's @states field + * @name: the name of this state + * @settings: a list of settings for this state + */ +struct pinctrl_state { + struct list_head node; + const char *name; struct list_head settings; }; /** * struct pinctrl_setting - an individual mux setting - * @node: list node for struct pinctrl's @settings field + * @node: list node for struct pinctrl_settings's @settings field * @pctldev: pin control device handling to be programmed * @group_selector: the group selector to program * @func_selector: the function selector to program |