diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/Makefile | 1 | ||||
| -rw-r--r-- | drivers/base/dd.c | 7 | ||||
| -rw-r--r-- | drivers/base/pinctrl.c | 69 | ||||
| -rw-r--r-- | drivers/pinctrl/core.c | 30 | ||||
| -rw-r--r-- | drivers/pinctrl/core.h | 3 |
5 files changed, 106 insertions, 4 deletions
diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 5aa2d703d19f..4e22ce3ed73d 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -21,6 +21,7 @@ endif obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o obj-$(CONFIG_REGMAP) += regmap/ obj-$(CONFIG_SOC_BUS) += soc.o +obj-$(CONFIG_PINCTRL) += pinctrl.o ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG diff --git a/drivers/base/dd.c b/drivers/base/dd.c index e3bbed8a617c..656310156dde 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -24,6 +24,7 @@ #include <linux/wait.h> #include <linux/async.h> #include <linux/pm_runtime.h> +#include <linux/pinctrl/devinfo.h> #include "base.h" #include "power/power.h" @@ -269,6 +270,12 @@ static int really_probe(struct device *dev, struct device_driver *drv) WARN_ON(!list_empty(&dev->devres_head)); dev->driver = drv; + + /* If using pinctrl, bind pins now before probing */ + ret = pinctrl_bind_pins(dev); + if (ret) + goto probe_failed; + if (driver_sysfs_add(dev)) { printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n", __func__, dev_name(dev)); diff --git a/drivers/base/pinctrl.c b/drivers/base/pinctrl.c new file mode 100644 index 000000000000..67a274e86727 --- /dev/null +++ b/drivers/base/pinctrl.c @@ -0,0 +1,69 @@ +/* + * Driver core interface to the pinctrl subsystem. + * + * Copyright (C) 2012 ST-Ericsson SA + * Written on behalf of Linaro for ST-Ericsson + * Based on bits of regulator core, gpio core and clk core + * + * Author: Linus Walleij <linus.walleij@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include <linux/device.h> +#include <linux/pinctrl/devinfo.h> +#include <linux/pinctrl/consumer.h> +#include <linux/slab.h> + +/** + * pinctrl_bind_pins() - called by the device core before probe + * @dev: the device that is just about to probe + */ +int pinctrl_bind_pins(struct device *dev) +{ + int ret; + + dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL); + if (!dev->pins) + return -ENOMEM; + + dev->pins->p = devm_pinctrl_get(dev); + if (IS_ERR(dev->pins->p)) { + dev_dbg(dev, "no pinctrl handle\n"); + ret = PTR_ERR(dev->pins->p); + goto cleanup_alloc; + } + + dev->pins->default_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_DEFAULT); + if (IS_ERR(dev->pins->default_state)) { + dev_dbg(dev, "no default pinctrl state\n"); + ret = 0; + goto cleanup_get; + } + + ret = pinctrl_select_state(dev->pins->p, dev->pins->default_state); + if (ret) { + dev_dbg(dev, "failed to activate default pinctrl state\n"); + goto cleanup_get; + } + + return 0; + + /* + * If no pinctrl handle or default state was found for this device, + * let's explicitly free the pin container in the device, there is + * no point in keeping it around. + */ +cleanup_get: + devm_pinctrl_put(dev->pins->p); +cleanup_alloc: + devm_kfree(dev, dev->pins); + dev->pins = NULL; + + /* Only return deferrals */ + if (ret != -EPROBE_DEFER) + ret = 0; + + return ret; +} diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index e6373f30aeeb..5a2fe9aae20f 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -14,6 +14,7 @@ #define pr_fmt(fmt) "pinctrl core: " fmt #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/export.h> #include <linux/init.h> #include <linux/device.h> @@ -727,6 +728,8 @@ static struct pinctrl *create_pinctrl(struct device *dev) return ERR_PTR(ret); } + kref_init(&p->users); + /* Add the pinctrl handle to the global list */ list_add_tail(&p->node, &pinctrl_list); @@ -740,9 +743,17 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev) if (WARN_ON(!dev)) return ERR_PTR(-EINVAL); + /* + * See if somebody else (such as the device core) has already + * obtained a handle to the pinctrl for this device. In that case, + * return another pointer to it. + */ p = find_pinctrl(dev); - if (p != NULL) - return ERR_PTR(-EBUSY); + if (p != NULL) { + dev_dbg(dev, "obtain a copy of previously claimed pinctrl\n"); + kref_get(&p->users); + return p; + } return create_pinctrl(dev); } @@ -798,13 +809,24 @@ static void pinctrl_put_locked(struct pinctrl *p, bool inlist) } /** - * pinctrl_put() - release a previously claimed pinctrl handle + * pinctrl_release() - release the pinctrl handle + * @kref: the kref in the pinctrl being released + */ +void pinctrl_release(struct kref *kref) +{ + struct pinctrl *p = container_of(kref, struct pinctrl, users); + + pinctrl_put_locked(p, true); +} + +/** + * pinctrl_put() - decrease use count on a previously claimed pinctrl handle * @p: the pinctrl handle to release */ void pinctrl_put(struct pinctrl *p) { mutex_lock(&pinctrl_mutex); - pinctrl_put_locked(p, true); + kref_put(&p->users, pinctrl_release); mutex_unlock(&pinctrl_mutex); } EXPORT_SYMBOL_GPL(pinctrl_put); diff --git a/drivers/pinctrl/core.h b/drivers/pinctrl/core.h index 232a9f6db4aa..fdd350d639f6 100644 --- a/drivers/pinctrl/core.h +++ b/drivers/pinctrl/core.h @@ -9,6 +9,7 @@ * License terms: GNU General Public License (GPL) version 2 */ +#include <linux/kref.h> #include <linux/mutex.h> #include <linux/radix-tree.h> #include <linux/pinctrl/pinconf.h> @@ -58,6 +59,7 @@ struct pinctrl_dev { * @state: the current state * @dt_maps: the mapping table chunks dynamically parsed from device tree for * this device, if any + * @users: reference count */ struct pinctrl { struct list_head node; @@ -65,6 +67,7 @@ struct pinctrl { struct list_head states; struct pinctrl_state *state; struct list_head dt_maps; + struct kref users; }; /** |