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Commit 0171e31d authored by Ram Chandrasekar's avatar Ram Chandrasekar
Browse files

bcl: Add BCL framework driver 



Add a new BCL framework driver which provides interface
to configure and interact with the battery current limit
hardware.
This framework driver also provides a generic
interface for the hardware drivers to register with function
pointers, thus abstracting the underlying hardware from
the upper level kernel modules.

The BCL peripheral driver exposes the below read-only
sysfs nodes for user debugging.
-/sys/class/msm_bcl/voltage/value
  - Latest battery voltage value (uV)
-/sys/class/msm_bcl/voltage/high_trip
  - Active maximum battery voltage threshold  (uV)
-/sys/class/msm_bcl/voltage/low_trip
  - Active minimum battery voltage threshold  (uV)
-/sys/class/msm_bcl/current/value
  - Latest battery current value  (uA)
-/sys/class/msm_bcl/current/high_trip
  - Active maximum battery current threshold (uA)
-/sys/class/msm_bcl/current/low_trip
  - Active minimum battery current threshold (uA)

The bcl framework driver provides a data-structure to
input the trip threshold, trip type, trip notification,
and its associated data to be passed along the
notification.

The kernel drivers can use this data-structure to pass
the high and low trip threshold information for
battery voltage and current.

struct bcl_threshold {
    int                trip_value;
    enum bcl_trip_type type;
    void (*trip_notify)(enum bcl_trip_type, int, void *);
    void               *trip_data;
};

- int msm_bcl_enable(void);
- int msm_bcl_disable(void);
Kernel driver should use these interfaces to enable and
disable the BCL monitoring feature respectively.
The msm_bcl_enable(void) call will set the thresholds
for BCL monitoring and will enable hardware
BCL monitoring.

- int msm_bcl_set_threshold(enum bcl_param, enum bcl_trip_type,
    struct bcl_threshold *);
Kernel drivers should use this interface to program the
high trip and low trip thresholds along with their
notification callbacks for battery voltage and current.

- int msm_bcl_read(enum bcl_param, int *);
Kernel driver can use this interface to read the
last hardware sampled voltage and current reading
in micro-volts and micro-ampere respectively.

- struct bcl_param_data *msm_bcl_register_param(enum bcl_param,
    struct bcl_driver_ops *, char *);
- int msm_bcl_unregister_param(struct bcl_param_data *);
BCL hardware drivers should use this interface to register
with the BCL framework. The BCL hardware drivers should
define the ops functions required by the framework driver and
provide that as input using the struct bcl_driver_ops parameter.
The register function returns a struct bcl_param_data pointer
on success, which can be used as input for unregistering the
same from BCL framework driver.

struct bcl_driver_ops {
        int (*read)             (int *);
        int (*set_high_trip)    (int);
        int (*get_high_trip)    (int *);
        int (*set_low_trip)     (int);
        int (*get_low_trip)     (int *);
        int (*disable)          (void);
        int (*enable)           (void);
        int (*notify)           (struct bcl_param_data *, int,
                                        enum bcl_trip_type);
};
This BCL frmaework requires the BCL hardware drivers to have
interfaces implementing the above functionalities.

- read
This function should read the last hardware sampled value.

- set_high_trip
- get_high_trip
- set_low_trip
- get_low_trip
These functions should set and get the high trip and
low trip.

- disable
- enable
These functions should enable or disable the voltage or
current param monitoring.

-notify
BCL framework populates this function pointer with a generic
threshold handler interface. On reaching high/low trip, the
BCL hardware driver should call this notification handler
with appropriate input parameters.

Change-Id: I5ee544bdf0bce7114f8251799ea32b121bb4464c
Signed-off-by: default avatarRam Chandrasekar <rkumbako@codeaurora.org>
parent b853134f

drivers/power/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -526,6 +526,14 @@ config QPNP_LINEAR_CHARGER 
	  detection and charging. The driver also offers relevant information

	  to userspace via the power supply framework.



config MSM_BCL_CTL

	bool "BCL Framework driver"

	help

	  Say Y here to enable this BCL Framework driver. This driver provides

	  interface, which can be used by the BCL h/w drivers to implement the

	  basic functionalities. This framework abstracts the underlying

	  hardware for the top level modules.



source "drivers/power/reset/Kconfig"



endif # POWER_SUPPLY

drivers/power/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -67,5 +67,6 @@ obj-$(CONFIG_QPNP_SMBCHARGER) += qpnp-smbcharger.o 
obj-$(CONFIG_CHARGER_SMB347)	+= smb347-charger.o

obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o

obj-$(CONFIG_BATTERY_BCL)	+= battery_current_limit.o

obj-$(CONFIG_MSM_BCL_CTL)	+= msm_bcl.o

obj-$(CONFIG_POWER_RESET)	+= reset/

obj-y				+= qcom/

drivers/power/msm_bcl.c

0 → 100644
+374 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */



#define pr_fmt(fmt) "%s:%s " fmt, KBUILD_MODNAME, __func__



#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/interrupt.h>

#include <linux/workqueue.h>

#include <linux/kernel.h>

#include <linux/io.h>

#include <linux/err.h>

#include <linux/of.h>

#include <linux/sysfs.h>

#include <linux/mutex.h>

#include <linux/msm_bcl.h>

#include <linux/slab.h>



#define BCL_PARAM_MAX_ATTR      3



#define BCL_DEFINE_RO_PARAM(_attr, _name, _attr_gp, _index) \

	_attr.attr.name = __stringify(_name); \

	_attr.attr.mode = 0444; \

	_attr.show = _name##_show; \

	_attr_gp.attrs[_index] = &_attr.attr;



static struct bcl_param_data *bcl[BCL_PARAM_MAX];



static ssize_t high_trip_show(struct kobject *kobj, struct kobj_attribute *attr,

				char *buf)

{

	int val = 0, ret = 0;

	struct bcl_param_data *dev_param = container_of(attr,

			struct bcl_param_data, high_trip_attr);



	if (!dev_param->registered)

		return -ENODEV;



	ret = dev_param->ops->get_high_trip(&val);

	if (ret) {

		pr_err("High trip value read failed. err:%d\n", ret);

		return ret;

	}



	return snprintf(buf, PAGE_SIZE, "%d\n", val);

}



static ssize_t low_trip_show(struct kobject *kobj, struct kobj_attribute *attr,

				char *buf)

{

	int val = 0, ret = 0;

	struct bcl_param_data *dev_param = container_of(attr,

			struct bcl_param_data, low_trip_attr);



	if (!dev_param->registered)

		return -ENODEV;



	ret = dev_param->ops->get_low_trip(&val);

	if (ret) {

		pr_err("Low trip value read failed. err:%d\n", ret);

		return ret;

	}



	return snprintf(buf, PAGE_SIZE, "%d\n", val);

}



static ssize_t value_show(struct kobject *kobj, struct kobj_attribute *attr,

				char *buf)

{

	int32_t val = 0, ret = 0;

	struct bcl_param_data *dev_param = container_of(attr,

			struct bcl_param_data, val_attr);



	if (!dev_param->registered)

		return -ENODEV;



	ret = dev_param->ops->read(&val);

	if (ret) {

		pr_err("Value read failed. err:%d\n", ret);

		return ret;

	}

	dev_param->last_read_val = val;



	return snprintf(buf, PAGE_SIZE, "%d\n", val);

}



int msm_bcl_set_threshold(enum bcl_param param_type,

	enum bcl_trip_type trip_type, struct bcl_threshold *inp_thresh)

{

	int ret = 0;



	if (!bcl[param_type] || !bcl[param_type]->registered) {

		pr_err("BCL not initialized\n");

		return -EINVAL;

	}

	if ((!inp_thresh)

		|| (inp_thresh->trip_value < 0)

		|| (!inp_thresh->trip_notify)

		|| (param_type >= BCL_PARAM_MAX)

		|| (trip_type >= BCL_TRIP_MAX)) {

		pr_err("Invalid Input\n");

		return -EINVAL;

	}



	bcl[param_type]->thresh[trip_type] = inp_thresh;

	if (trip_type == BCL_HIGH_TRIP) {

		bcl[param_type]->high_trip = inp_thresh->trip_value;

		ret = bcl[param_type]->ops->set_high_trip(

			inp_thresh->trip_value);

	} else {

		bcl[param_type]->low_trip = inp_thresh->trip_value;

		ret = bcl[param_type]->ops->set_low_trip(

			inp_thresh->trip_value);

	}

	if (ret) {

		pr_err("Error setting trip%d for param%d. err:%d\n", trip_type,

				 param_type, ret);

		return ret;

	}



	return ret;

}



static int bcl_thresh_notify(struct bcl_param_data *param_data, int val,

					enum bcl_trip_type trip_type)

{

	if (!param_data || trip_type >= BCL_TRIP_MAX

		|| !param_data->registered) {

		pr_err("Invalid input\n");

		return -EINVAL;

	}



	param_data->thresh[trip_type]->trip_notify(trip_type, val,

		param_data->thresh[trip_type]->trip_data);



	return 0;

}



static int bcl_add_sysfs_nodes(enum bcl_param param_type);

struct bcl_param_data *msm_bcl_register_param(enum bcl_param param_type,

	struct bcl_driver_ops *param_ops, char *name)

{

	int ret = 0;



	if (!bcl[param_type]

		|| param_type >= BCL_PARAM_MAX || !param_ops || !name

		|| !param_ops->read || !param_ops->set_high_trip

		|| !param_ops->get_high_trip || !param_ops->set_low_trip

		|| !param_ops->get_low_trip || !param_ops->enable

		|| !param_ops->disable) {

		pr_err("Invalid input\n");

		return NULL;

	}

	if (bcl[param_type]->registered) {

		pr_err("param%d already initialized\n", param_type);

		return NULL;

	}



	ret = bcl_add_sysfs_nodes(param_type);

	if (ret) {

		pr_err("Error creating sysfs nodes. err:%d\n", ret);

		return NULL;

	}

	bcl[param_type]->ops = param_ops;

	bcl[param_type]->registered = true;

	strlcpy(bcl[param_type]->name, name, BCL_NAME_MAX_LEN);

	param_ops->notify = bcl_thresh_notify;



	return bcl[param_type];

}



int msm_bcl_unregister_param(struct bcl_param_data *param_data)

{

	int i = 0, ret = -EINVAL;



	if (!bcl[i] || !param_data) {

		pr_err("Invalid input\n");

		return ret;

	}

	for (; i < BCL_PARAM_MAX; i++) {

		if (param_data != bcl[i])

			continue;

		bcl[i]->ops->disable();

		bcl[i]->registered = false;

		ret = 0;

		break;

	}



	return ret;

}



int msm_bcl_disable(void)

{

	int ret = 0, i = 0;



	if (!bcl[i]) {

		pr_err("BCL not initialized\n");

		return -EINVAL;

	}



	for (; i < BCL_PARAM_MAX; i++) {

		if (!bcl[i]->registered)

			continue;

		ret = bcl[i]->ops->disable();

		if (ret) {

			pr_err("Error in disabling interrupt. param:%d err%d\n",

				i, ret);

			return ret;

		}

	}



	return ret;

}



int msm_bcl_enable(void)

{

	int ret = 0, i = 0;

	struct bcl_param_data *param_data = NULL;



	if (!bcl[i] || !bcl[BCL_PARAM_VOLTAGE]->thresh

		|| !bcl[BCL_PARAM_CURRENT]->thresh) {

		pr_err("BCL not initialized\n");

		return -EINVAL;

	}



	for (; i < BCL_PARAM_MAX; i++) {

		if (!bcl[i]->registered)

			continue;

		param_data = bcl[i];

		ret = param_data->ops->set_high_trip(param_data->high_trip);

		if (ret) {

			pr_err("Error setting high trip. param:%d. err:%d",

				i, ret);

			return ret;

		}

		ret = param_data->ops->set_low_trip(param_data->low_trip);

		if (ret) {

			pr_err("Error setting low trip. param:%d. err:%d",

				i, ret);

			return ret;

		}

		ret = param_data->ops->enable();

		if (ret) {

			pr_err("Error enabling interrupt. param:%d. err:%d",

				i, ret);

			return ret;

		}

	}



	return ret;

}



int msm_bcl_read(enum bcl_param param_type, int *value)

{

	int ret = 0;



	if (!value || param_type >= BCL_PARAM_MAX) {

		pr_err("Invalid input\n");

		return -EINVAL;

	}

	if (!bcl[param_type] || !bcl[param_type]->registered) {

		pr_err("BCL driver not initialized\n");

		return -ENOSYS;

	}



	ret = bcl[param_type]->ops->read(value);

	if (ret) {

		pr_err("Error reading param%d. err:%d\n", param_type, ret);

		return ret;

	}

	bcl[param_type]->last_read_val = *value;



	return ret;

}



static struct class msm_bcl_class = {

	.name = "msm_bcl",

};



static int bcl_add_sysfs_nodes(enum bcl_param param_type)

{

	char *param_name[BCL_PARAM_MAX] = {"voltage", "current"};

	int ret = 0;



	bcl[param_type]->device.class = &msm_bcl_class;

	dev_set_name(&bcl[param_type]->device, "%s", param_name[param_type]);

	ret = device_register(&bcl[param_type]->device);

	if (ret) {

		pr_err("Error registering device %s. err:%d\n",

			param_name[param_type], ret);

		return ret;

	}

	bcl[param_type]->bcl_attr_gp.attrs = kzalloc(sizeof(struct attribute *)

		* BCL_PARAM_MAX_ATTR + 1, GFP_KERNEL);

	if (!bcl[param_type]->bcl_attr_gp.attrs) {

		pr_err("Sysfs attribute create failed.\n");

		ret = -ENOMEM;

		goto add_sysfs_exit;

	}

	BCL_DEFINE_RO_PARAM(bcl[param_type]->val_attr, value,

		bcl[param_type]->bcl_attr_gp, 0);

	BCL_DEFINE_RO_PARAM(bcl[param_type]->high_trip_attr, high_trip,

		bcl[param_type]->bcl_attr_gp, 1);

	BCL_DEFINE_RO_PARAM(bcl[param_type]->low_trip_attr, low_trip,

		bcl[param_type]->bcl_attr_gp, 2);

	bcl[param_type]->bcl_attr_gp.attrs[BCL_PARAM_MAX_ATTR] = NULL;



	ret = sysfs_create_group(&bcl[param_type]->device.kobj,

		&bcl[param_type]->bcl_attr_gp);

	if (ret) {

		pr_err("Failure to create sysfs nodes. err:%d", ret);

		goto add_sysfs_exit;

	}



add_sysfs_exit:

	return ret;

}



static int msm_bcl_init(void)

{

	int ret = 0, i = 0;



	for (; i < BCL_PARAM_MAX; i++) {

		bcl[i] = kzalloc(sizeof(struct bcl_param_data),

			GFP_KERNEL);

		if (!bcl[i]) {

			pr_err("kzalloc failed\n");

			while ((--i) >= 0)

				kfree(bcl[i]);

			return -ENOMEM;

		}

	}



	return ret;

}





static int __init msm_bcl_init_driver(void)

{

	int ret = 0;



	ret = msm_bcl_init();

	if (ret) {

		pr_err("msm bcl init failed. err:%d\n", ret);

		return ret;

	}

	return class_register(&msm_bcl_class);

}



static void __exit bcl_exit(void)

{

	int i = 0;



	for (; i < BCL_PARAM_MAX; i++) {

		sysfs_remove_group(&bcl[i]->device.kobj,

			&bcl[i]->bcl_attr_gp);

		kfree(bcl[i]->bcl_attr_gp.attrs);

		kfree(bcl[i]);

	}

	class_unregister(&msm_bcl_class);

}



fs_initcall(msm_bcl_init_driver);

module_exit(bcl_exit);

include/linux/msm_bcl.h

0 → 100644
+104 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */



#ifndef __MSM_BCL_H

#define __MSM_BCL_H



#define BCL_NAME_MAX_LEN 20



enum bcl_trip_type {

	BCL_HIGH_TRIP,

	BCL_LOW_TRIP,

	BCL_TRIP_MAX,

};



enum bcl_param {

	BCL_PARAM_VOLTAGE,

	BCL_PARAM_CURRENT,

	BCL_PARAM_MAX,

};



struct bcl_threshold {

	int                     trip_value;

	enum bcl_trip_type      type;

	void                    *trip_data;

	void (*trip_notify)     (enum bcl_trip_type, int, void *);

};

struct bcl_param_data;

struct bcl_driver_ops {

	int (*read)             (int *);

	int (*set_high_trip)    (int);

	int (*get_high_trip)    (int *);

	int (*set_low_trip)     (int);

	int (*get_low_trip)     (int *);

	int (*disable)          (void);

	int (*enable)           (void);

	int (*notify)           (struct bcl_param_data *, int,

					enum bcl_trip_type);

};



struct bcl_param_data {

	char                    name[BCL_NAME_MAX_LEN];

	struct device           device;

	struct bcl_driver_ops   *ops;

	int                     high_trip;

	int                     low_trip;

	int                     last_read_val;

	bool                    registered;

	struct kobj_attribute   val_attr;

	struct kobj_attribute   high_trip_attr;

	struct kobj_attribute   low_trip_attr;

	struct attribute_group  bcl_attr_gp;

	struct bcl_threshold    *thresh[BCL_TRIP_MAX];

};



#ifdef CONFIG_MSM_BCL_CTL

struct bcl_param_data *msm_bcl_register_param(enum bcl_param,

	struct bcl_driver_ops *, char *);

int msm_bcl_unregister_param(struct bcl_param_data *);

int msm_bcl_enable(void);

int msm_bcl_disable(void);

int msm_bcl_set_threshold(enum bcl_param, enum bcl_trip_type,

	struct bcl_threshold *);

int msm_bcl_read(enum bcl_param, int *);

#else

static inline struct bcl_param_data *msm_bcl_register_param(

	enum bcl_param param_type, struct bcl_driver_ops *ops, char *name)

{

	return NULL;

}

static inline int msm_bcl_unregister_param(struct bcl_param_data *data)

{

	return -ENOSYS;

}

static inline int msm_bcl_enable(void)

{

	return -ENOSYS;

}

static inline int msm_bcl_disable(void)

{

	return -ENOSYS;

}

static inline int msm_bcl_set_threshold(enum bcl_param param_type,

	enum bcl_trip_type type,

	struct bcl_threshold *inp_thresh)

{

	return -ENOSYS;

}

static inline int msm_bcl_read(enum bcl_param param_type, int *vbat_value)

{

	return -ENOSYS;

}

#endif



#endif /*__MSM_BCL_H*/