Port an extremely abridged version of power management/power domain code from Linux as a dependency of i.MX7D PCIe work. Currenlty only bare minimum of functionality is implemented. Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx> --- drivers/Kconfig | 1 + drivers/base/Kconfig | 3 + drivers/base/Makefile | 4 +- drivers/base/platform.c | 7 ++ drivers/base/power.c | 245 ++++++++++++++++++++++++++++++++++++++++ include/pm_domain.h | 82 ++++++++++++++ 6 files changed, 341 insertions(+), 1 deletion(-) create mode 100644 drivers/base/Kconfig create mode 100644 drivers/base/power.c create mode 100644 include/pm_domain.h diff --git a/drivers/Kconfig b/drivers/Kconfig index 1e0246da6..c3bf9dfe1 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -1,5 +1,6 @@ menu "Drivers" +source "drivers/base/Kconfig" source "drivers/efi/Kconfig" source "drivers/of/Kconfig" source "drivers/aiodev/Kconfig" diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig new file mode 100644 index 000000000..1e13e5ed9 --- /dev/null +++ b/drivers/base/Kconfig @@ -0,0 +1,3 @@ + +config PM_GENERIC_DOMAINS + bool diff --git a/drivers/base/Makefile b/drivers/base/Makefile index 4bd421774..6d2cef8e1 100644 --- a/drivers/base/Makefile +++ b/drivers/base/Makefile @@ -2,4 +2,6 @@ obj-y += bus.o obj-y += driver.o obj-y += platform.o obj-y += resource.o -obj-y += regmap/ \ No newline at end of file +obj-y += regmap/ + +obj-$(CONFIG_PM_GENERIC_DOMAINS) += power.o diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 85bdfb014..1d3fa2eb4 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -21,9 +21,16 @@ #include <errno.h> #include <init.h> #include <of.h> +#include <pm_domain.h> static int platform_probe(struct device_d *dev) { + int ret; + + ret = genpd_dev_pm_attach(dev); + if (ret < 0) + return ret; + return dev->driver->probe(dev); } diff --git a/drivers/base/power.c b/drivers/base/power.c new file mode 100644 index 000000000..fd9c4e2ba --- /dev/null +++ b/drivers/base/power.c @@ -0,0 +1,245 @@ +#include <common.h> +#include <driver.h> +#include <errno.h> +#include <of.h> + +#include <pm_domain.h> + +#define genpd_status_on(genpd) (genpd->status == GPD_STATE_ACTIVE) + +static LIST_HEAD(gpd_list); + +/** + * pm_genpd_init - Initialize a generic I/O PM domain object. + * @genpd: PM domain object to initialize. + * @gov: PM domain governor to associate with the domain (may be NULL). + * @is_off: Initial value of the domain's power_is_off field. + * + * Returns 0 on successful initialization, else a negative error code. + */ +int pm_genpd_init(struct generic_pm_domain *genpd, void *gov, bool is_off) +{ + if (IS_ERR_OR_NULL(genpd)) + return -EINVAL; + + genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE; + + list_add(&genpd->gpd_list_node, &gpd_list); + + return 0; +} +EXPORT_SYMBOL_GPL(pm_genpd_init); + +/** + * struct of_genpd_provider - PM domain provider registration structure + * @link: Entry in global list of PM domain providers + * @node: Pointer to device tree node of PM domain provider + * @xlate: Provider-specific xlate callback mapping a set of specifier cells + * into a PM domain. + * @data: context pointer to be passed into @xlate callback + */ +struct of_genpd_provider { + struct list_head link; + struct device_node *node; + genpd_xlate_t xlate; + void *data; +}; + +/* List of registered PM domain providers. */ +static LIST_HEAD(of_genpd_providers); + +static bool genpd_present(const struct generic_pm_domain *genpd) +{ + const struct generic_pm_domain *gpd; + + if (IS_ERR_OR_NULL(genpd)) + return false; + + list_for_each_entry(gpd, &gpd_list, gpd_list_node) + if (gpd == genpd) + return true; + + return false; +} + +/** + * genpd_xlate_simple() - Xlate function for direct node-domain mapping + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct generic_pm_domain + * + * This is a generic xlate function that can be used to model PM domains that + * have their own device tree nodes. The private data of xlate function needs + * to be a valid pointer to struct generic_pm_domain. + */ +static struct generic_pm_domain *genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data) +{ + return data; +} + +/** + * genpd_add_provider() - Register a PM domain provider for a node + * @np: Device node pointer associated with the PM domain provider. + * @xlate: Callback for decoding PM domain from phandle arguments. + * @data: Context pointer for @xlate callback. + */ +static int genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data) +{ + struct of_genpd_provider *cp; + + cp = kzalloc(sizeof(*cp), GFP_KERNEL); + if (!cp) + return -ENOMEM; + + cp->node = np; + cp->data = data; + cp->xlate = xlate; + + list_add(&cp->link, &of_genpd_providers); + pr_debug("Added domain provider from %pOF\n", np); + + return 0; +} + +/** + * of_genpd_add_provider_simple() - Register a simple PM domain provider + * @np: Device node pointer associated with the PM domain provider. + * @genpd: Pointer to PM domain associated with the PM domain provider. + */ +int of_genpd_add_provider_simple(struct device_node *np, + struct generic_pm_domain *genpd) +{ + int ret = -EINVAL; + + if (!np || !genpd) + return -EINVAL; + + if (genpd_present(genpd)) + ret = genpd_add_provider(np, genpd_xlate_simple, genpd); + + return ret; +} +EXPORT_SYMBOL_GPL(of_genpd_add_provider_simple); + +/** + * genpd_get_from_provider() - Look-up PM domain + * @genpdspec: OF phandle args to use for look-up + * + * Looks for a PM domain provider under the node specified by @genpdspec and if + * found, uses xlate function of the provider to map phandle args to a PM + * domain. + * + * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR() + * on failure. + */ +static struct generic_pm_domain *genpd_get_from_provider( + struct of_phandle_args *genpdspec) +{ + struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); + struct of_genpd_provider *provider; + + if (!genpdspec) + return ERR_PTR(-EINVAL); + + /* Check if we have such a provider in our array */ + list_for_each_entry(provider, &of_genpd_providers, link) { + if (provider->node == genpdspec->np) + genpd = provider->xlate(genpdspec, provider->data); + if (!IS_ERR(genpd)) + break; + } + + return genpd; +} + +static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed) +{ + if (!genpd->power_on) + return 0; + + return genpd->power_on(genpd); +} + +/** + * genpd_power_on - Restore power to a given PM domain and its masters. + * @genpd: PM domain to power up. + * @depth: nesting count for lockdep. + * + * Restore power to @genpd and all of its masters so that it is possible to + * resume a device belonging to it. + */ +static int genpd_power_on(struct generic_pm_domain *genpd, unsigned int depth) +{ + int ret; + + if (genpd_status_on(genpd)) + return 0; + + ret = _genpd_power_on(genpd, true); + if (ret) + return ret; + + genpd->status = GPD_STATE_ACTIVE; + + return 0; +} + +static int __genpd_dev_pm_attach(struct device_d *dev, struct device_node *np, + unsigned int index, bool power_on) +{ + struct of_phandle_args pd_args; + struct generic_pm_domain *pd; + int ret; + + ret = of_parse_phandle_with_args(np, "power-domains", + "#power-domain-cells", index, &pd_args); + if (ret < 0) + return ret; + + pd = genpd_get_from_provider(&pd_args); + if (IS_ERR(pd)) { + ret = PTR_ERR(pd); + dev_dbg(dev, "%s() failed to find PM domain: %d\n", + __func__, ret); + return driver_deferred_probe_check_state(dev); + } + + dev_dbg(dev, "adding to PM domain %s\n", pd->name); + + if (power_on) + ret = genpd_power_on(pd, 0); + + return ret ?: 1; +} + +/** + * genpd_dev_pm_attach - Attach a device to its PM domain using DT. + * @dev: Device to attach. + * + * Parse device's OF node to find a PM domain specifier. If such is found, + * attaches the device to retrieved pm_domain ops. + * + * Returns 1 on successfully attached PM domain, 0 when the device don't need a + * PM domain or when multiple power-domains exists for it, else a negative error + * code. Note that if a power-domain exists for the device, but it cannot be + * found or turned on, then return -EPROBE_DEFER to ensure that the device is + * not probed and to re-try again later. + */ +int genpd_dev_pm_attach(struct device_d *dev) +{ + if (!dev->device_node) + return 0; + + /* + * Devices with multiple PM domains must be attached separately, as we + * can only attach one PM domain per device. + */ + if (of_count_phandle_with_args(dev->device_node, "power-domains", + "#power-domain-cells") != 1) + return 0; + + return __genpd_dev_pm_attach(dev, dev->device_node, 0, true); +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); diff --git a/include/pm_domain.h b/include/pm_domain.h new file mode 100644 index 000000000..6d59587ec --- /dev/null +++ b/include/pm_domain.h @@ -0,0 +1,82 @@ +#ifndef _PM_DOMAIN_H +#define _PM_DOMAIN_H + +enum gpd_status { + GPD_STATE_ACTIVE = 0, /* PM domain is active */ + GPD_STATE_POWER_OFF, /* PM domain is off */ +}; + +struct generic_pm_domain { + const char *name; + struct list_head gpd_list_node; /* Node in the global PM domains list */ + + enum gpd_status status; /* Current state of the domain */ + + int (*power_off)(struct generic_pm_domain *domain); + int (*power_on)(struct generic_pm_domain *domain); +}; + +typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, + void *data); + +#ifdef CONFIG_PM_GENERIC_DOMAINS + +int genpd_dev_pm_attach(struct device_d *dev); + +/** + * dev_pm_domain_attach - Attach a device to its PM domain. + * @dev: Device to attach. + * @power_on: Used to indicate whether we should power on the device. + * + * The @dev may only be attached to a single PM domain. By iterating through + * the available alternatives we try to find a valid PM domain for the device. + * As attachment succeeds, the ->detach() callback in the struct dev_pm_domain + * should be assigned by the corresponding attach function. + * + * This function should typically be invoked from subsystem level code during + * the probe phase. Especially for those that holds devices which requires + * power management through PM domains. + * + * Callers must ensure proper synchronization of this function with power + * management callbacks. + * + * Returns 0 on successfully attached PM domain or negative error code. + */ +static inline int dev_pm_domain_attach(struct device_d *dev, bool power_on) +{ + return genpd_dev_pm_attach(dev); +} + +int pm_genpd_init(struct generic_pm_domain *genpd, void *gov, bool is_off); + +int of_genpd_add_provider_simple(struct device_node *np, + struct generic_pm_domain *genpd); + +#else + +static inline int pm_genpd_init(struct generic_pm_domain *genpd, + void *gov, bool is_off) +{ + return -ENOSYS; +} + +static inline int genpd_dev_pm_attach(struct device_d *dev) +{ + return 0; +} + +static inline int dev_pm_domain_attach(struct device_d *dev, bool power_on) +{ + return 0; +} + +static inline int +of_genpd_add_provider_simple(struct device_node *np, + struct generic_pm_domain *genpd) +{ + return -ENOTSUPP; +} + +#endif + +#endif \ No newline at end of file -- 2.20.1 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox