diff options
Diffstat (limited to 'kernel/drivers/base/pinctrl.c')
-rw-r--r-- | kernel/drivers/base/pinctrl.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/kernel/drivers/base/pinctrl.c b/kernel/drivers/base/pinctrl.c new file mode 100644 index 000000000..5fb74b438 --- /dev/null +++ b/kernel/drivers/base/pinctrl.c @@ -0,0 +1,88 @@ +/* + * 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; + } + +#ifdef CONFIG_PM + /* + * If power management is enabled, we also look for the optional + * sleep and idle pin states, with semantics as defined in + * <linux/pinctrl/pinctrl-state.h> + */ + dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_SLEEP); + if (IS_ERR(dev->pins->sleep_state)) + /* Not supplying this state is perfectly legal */ + dev_dbg(dev, "no sleep pinctrl state\n"); + + dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p, + PINCTRL_STATE_IDLE); + if (IS_ERR(dev->pins->idle_state)) + /* Not supplying this state is perfectly legal */ + dev_dbg(dev, "no idle pinctrl state\n"); +#endif + + 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; +} |