[PATCH 1/3] soc: fsl: add Platform PM driver QorIQ platforms

[Wang, Dongsheng]

Please change your comments style.

On 2018/8/31 11:57, Ran Wang wrote:
> This driver is to provide a independent framework for PM service
> provider and consumer to configure system level wake up feature. For
> example, RCPM driver could register a callback function on this
> platform first, and Flex timer driver who want to enable timer wake
> up feature, will call generic API provided by this platform driver,
> and then it will trigger RCPM driver to do it. The benefit is to
> isolate the user and service, such as flex timer driver will not have
> to know the implement details of wakeup function it require. Besides,
> it is also easy for service side to upgrade its logic when design is
> changed and remain user side unchanged.
>
> Signed-off-by: Ran Wang <ran.wang_1 at nxp.com>
> ---
>  drivers/soc/fsl/Kconfig   |   14 +++++
>  drivers/soc/fsl/Makefile  |    1 +
>  drivers/soc/fsl/plat_pm.c |  144 +++++++++++++++++++++++++++++++++++++++++++++
>  include/soc/fsl/plat_pm.h |   22 +++++++
>  4 files changed, 181 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/soc/fsl/plat_pm.c
>  create mode 100644 include/soc/fsl/plat_pm.h
>
> diff --git a/drivers/soc/fsl/Kconfig b/drivers/soc/fsl/Kconfig
> index 7a9fb9b..6517412 100644
> --- a/drivers/soc/fsl/Kconfig
> +++ b/drivers/soc/fsl/Kconfig
> @@ -16,3 +16,17 @@ config FSL_GUTS
>  	  Initially only reading SVR and registering soc device are supported.
>  	  Other guts accesses, such as reading RCW, should eventually be moved
>  	  into this driver as well.
> +
> +config FSL_PLAT_PM
> +	bool "Freescale platform PM framework"
> +	help
> +	  This driver is to provide a independent framework for PM service
> +	  provider and consumer to configure system level wake up feature. For
> +	  example, RCPM driver could register a callback function on this
> +	  platform first, and Flex timer driver who want to enable timer wake
> +	  up feature, will call generic API provided by this platform driver,
> +	  and then it will trigger RCPM driver to do it. The benefit is to
> +	  isolate the user and service, such as  flex timer driver will not
> +	  have to know the implement details of wakeup function it require.
> +	  Besides, it is also easy for service side to upgrade its logic when
> +	  design changed and remain user side unchanged.
> diff --git a/drivers/soc/fsl/Makefile b/drivers/soc/fsl/Makefile
> index 44b3beb..8f9db23 100644
> --- a/drivers/soc/fsl/Makefile
> +++ b/drivers/soc/fsl/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_FSL_DPAA)                 += qbman/
>  obj-$(CONFIG_QUICC_ENGINE)		+= qe/
>  obj-$(CONFIG_CPM)			+= qe/
>  obj-$(CONFIG_FSL_GUTS)			+= guts.o
> +obj-$(CONFIG_FSL_PLAT_PM)	+= plat_pm.o
> diff --git a/drivers/soc/fsl/plat_pm.c b/drivers/soc/fsl/plat_pm.c
> new file mode 100644
> index 0000000..19ea14e
> --- /dev/null
> +++ b/drivers/soc/fsl/plat_pm.c
> @@ -0,0 +1,144 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// plat_pm.c - Freescale platform PM framework
> +//
> +// Copyright 2018 NXP
> +//
> +// Author: Ran Wang <ran.wang_1 at nxp.com>,
> +
> +#include <linux/kernel.h>
> +#include <linux/device.h>
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <linux/err.h>
> +#include <soc/fsl/plat_pm.h>
> +
> +
> +struct plat_pm_t {
> +	struct list_head node;
> +	fsl_plat_pm_handle handle;
> +	void *handle_priv;
> +	spinlock_t	lock;
> +};
> +
> +static struct plat_pm_t plat_pm;
> +
> +// register_fsl_platform_wakeup_source - Register callback function to plat_pm
> +// @handle: Pointer to handle PM feature requirement
> +// @handle_priv: Handler specific data struct
> +//
> +// Return 0 on success other negative errno
> +int register_fsl_platform_wakeup_source(fsl_plat_pm_handle handle,
> +		void *handle_priv)
> +{
> +	struct plat_pm_t *p;
> +	unsigned long	flags;
> +
> +	if (!handle) {
> +		pr_err("FSL plat_pm: Handler invalid, reject\n");
> +		return -EINVAL;
> +	}
> +
> +	p = kmalloc(sizeof(*p), GFP_KERNEL);
> +	if (!p)
> +		return -ENOMEM;
> +
> +	p->handle = handle;
> +	p->handle_priv = handle_priv;
> +
> +	spin_lock_irqsave(&plat_pm.lock, flags);
> +	list_add_tail(&p->node, &plat_pm.node);
> +	spin_unlock_irqrestore(&plat_pm.lock, flags);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(register_fsl_platform_wakeup_source);
> +
> +// Deregister_fsl_platform_wakeup_source - deregister callback function
> +// @handle_priv: Handler specific data struct
> +//
> +// Return 0 on success other negative errno
> +int deregister_fsl_platform_wakeup_source(void *handle_priv)
> +{
> +	struct plat_pm_t *p, *tmp;
> +	unsigned long	flags;
> +
> +	spin_lock_irqsave(&plat_pm.lock, flags);
> +	list_for_each_entry_safe(p, tmp, &plat_pm.node, node) {
> +		if (p->handle_priv == handle_priv) {
> +			list_del(&p->node);
> +			kfree(p);
> +		}
> +	}
> +	spin_unlock_irqrestore(&plat_pm.lock, flags);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(deregister_fsl_platform_wakeup_source);
> +
> +// fsl_platform_wakeup_config - Configure wakeup source by calling handlers
> +// @dev: pointer to user's device struct
> +// @flag: to tell enable or disable wakeup source
> +//
> +// Return 0 on success other negative errno
> +int fsl_platform_wakeup_config(struct device *dev, bool flag)
> +{
> +	struct plat_pm_t *p;
> +	int ret;
> +	bool success_handled;
> +	unsigned long	flags;
> +
> +	success_handled = false;
> +
> +	// Will consider success if at least one callback return 0.
> +	// Also, rest handles still get oppertunity to be executed
> +	spin_lock_irqsave(&plat_pm.lock, flags);
> +	list_for_each_entry(p, &plat_pm.node, node) {
> +		if (p->handle) {
> +			ret = p->handle(dev, flag, p->handle_priv);
> +			if (!ret)
> +				success_handled = true;
Miss a break?

> +			else if (ret != -ENODEV) {
> +				pr_err("FSL plat_pm: Failed to config wakeup source:%d\n", ret);
Please unlock before return.

> +				return ret;
> +			}
> +		} else
> +			pr_warn("FSL plat_pm: Invalid handler detected, skip\n");
> +	}
> +	spin_unlock_irqrestore(&plat_pm.lock, flags);
> +
> +	if (success_handled == false) {
> +		pr_err("FSL plat_pm: Cannot find the matchhed handler for wakeup source config\n");
> +		return -ENODEV;
> +	}
Add this into the loop.
> +
> +	return 0;
> +}
> +
> +// fsl_platform_wakeup_enable - Enable wakeup source
> +// @dev: pointer to user's device struct
> +//
> +// Return 0 on success other negative errno
> +int fsl_platform_wakeup_enable(struct device *dev)
> +{
> +	return fsl_platform_wakeup_config(dev, true);
> +}
> +EXPORT_SYMBOL_GPL(fsl_platform_wakeup_enable);
> +
> +// fsl_platform_wakeup_disable - Disable wakeup source
> +// @dev: pointer to user's device struct
> +//
> +// Return 0 on success other negative errno
> +int fsl_platform_wakeup_disable(struct device *dev)
> +{
> +	return fsl_platform_wakeup_config(dev, false);
> +}
> +EXPORT_SYMBOL_GPL(fsl_platform_wakeup_disable);
> +
> +static int __init fsl_plat_pm_init(void)
> +{
> +	spin_lock_init(&plat_pm.lock);
> +	INIT_LIST_HEAD(&plat_pm.node);
> +	return 0;
> +}
> +
> +core_initcall(fsl_plat_pm_init);
> diff --git a/include/soc/fsl/plat_pm.h b/include/soc/fsl/plat_pm.h
> new file mode 100644
> index 0000000..bbe151e
> --- /dev/null
> +++ b/include/soc/fsl/plat_pm.h
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// plat_pm.h - Freescale platform PM Header
> +//
> +// Copyright 2018 NXP
> +//
> +// Author: Ran Wang <ran.wang_1 at nxp.com>,
> +
> +#ifndef __FSL_PLAT_PM_H
> +#define __FSL_PLAT_PM_H
> +
> +typedef int (*fsl_plat_pm_handle)(struct device *dev, bool flag,
> +		void *handle_priv);
> +
> +int register_fsl_platform_wakeup_source(fsl_plat_pm_handle handle,
> +		void *handle_priv);
> +int deregister_fsl_platform_wakeup_source(void *handle_priv);
> +int fsl_platform_wakeup_config(struct device *dev, bool flag);
> +int fsl_platform_wakeup_enable(struct device *dev);
> +int fsl_platform_wakeup_disable(struct device *dev);
> +
> +#endif	// __FSL_PLAT_PM_H