Re: [PATCH v2] charger-manager: Add support sysfs entry for charger

From: Anton Vorontsov
Date: Fri Sep 21 2012 - 19:46:51 EST


On Fri, Sep 21, 2012 at 06:49:37PM +0900, Chanwoo Choi wrote:
> This patch add support sysfs entry for each charger(regulator).
> Charger-manager use one or more chargers for charging battery but
> some charger isn't necessary on specific scenario. So, if some charger
> isn't needed, can disable specific charger through 'externally_control'
> entry while system is on state and confirm the information(name, state)
> of charger.
[...]
> the list of added sysfs entry
> - /sys/class/power_supply/battery/chargers/charger.[index]/name
> : show name of charger(regulator)
> - /sys/class/power_supply/battery/chargers/charger.[index]/state
> : show either enabled or disabled state of charger
> - /sys/class/power_supply/battery/chargers/charger.[index]/externally_control
>
> If 'externally_control' of specific charger is 1, Charger-manager cannot enable
> regulator for charging when charger cable is attached and charger must be
> maintained with disabled state. If 'externally_control' is zero, Charger-manager
> usually can control to enable/disable regulator.
>
> Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---

Thanks for your work, folks!

There are some serious issues wrt. the coding standards, though.

(I must confess that because of the issues I didn't look much into the
logic itself, I hope it works.)

> drivers/power/charger-manager.c | 174 ++++++++++++++++++++++++++++++++-
> include/linux/power/charger-manager.h | 19 ++++
> 2 files changed, 192 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
> index e92ec55..a1ab825 100644
> --- a/drivers/power/charger-manager.c
> +++ b/drivers/power/charger-manager.c
> @@ -22,6 +22,7 @@
> #include <linux/platform_device.h>
> #include <linux/power/charger-manager.h>
> #include <linux/regulator/consumer.h>
> +#include <linux/sysfs.h>
>
> static const char * const default_event_names[] = {
> [CM_EVENT_UNKNOWN] = "Unknown",
> @@ -332,6 +333,9 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
> cm->charging_end_time = 0;
>
> for (i = 0 ; i < desc->num_charger_regulators ; i++) {
> + if (desc->charger_regulators[i].externally_control)
> + continue;
> +
> err = regulator_enable(desc->charger_regulators[i].consumer);
> if (err < 0) {
> dev_warn(cm->dev,
> @@ -348,6 +352,9 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
> cm->charging_end_time = ktime_to_ms(ktime_get());
>
> for (i = 0 ; i < desc->num_charger_regulators ; i++) {
> + if (desc->charger_regulators[i].externally_control)
> + continue;
> +
> err = regulator_disable(desc->charger_regulators[i].consumer);
> if (err < 0) {
> dev_warn(cm->dev,
> @@ -1217,12 +1224,101 @@ static int charger_extcon_init(struct charger_manager *cm,
> return ret;
> }
>
> +/* help function of sysfs node to control charger(regulator) */
> +static ssize_t charger_name_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct charger_regulator *charger
> + = container_of(attr, struct charger_regulator, attr_name);

Here must be an empty line.

> + return sprintf(buf, "%s\n", charger->regulator_name);
> +}
> +
> +static ssize_t charger_state_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct charger_regulator *charger
> + = container_of(attr, struct charger_regulator, attr_state);
> + int state = 1;

= 1 is not needed. Instead, you could rewrite it as

int state = 0;

if (!charger->externally_control)
state = regulator_is_enabled(charger->consumer);

> + if (charger->externally_control)
> + state = 0;
> + else
> + state = regulator_is_enabled(charger->consumer);
> +
> + return sprintf(buf, "%s\n", state ? "enabled" : "disabled");
> +}
> +
> +static ssize_t charger_externally_control_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct charger_regulator *charger = container_of(attr,
> + struct charger_regulator, attr_externally_control);

Empty line is required.

> + return sprintf(buf, "%d\n", charger->externally_control);
> +}
> +
> +static ssize_t charger_externally_control_store(struct device *dev,
> + struct device_attribute *attr, const char *buf,
> + size_t count)
> +{
> + struct charger_regulator *charger
> + = container_of(attr, struct charger_regulator,
> + attr_externally_control);
> + struct charger_manager *cm = charger->cm;
> + struct charger_desc *desc = cm->desc;
> + int i, ret;

One variable declaration per line.

> + int externally_control;
> +
> + ret = sscanf(buf, "%d", &externally_control);
> + if (ret == 0) {
> + ret = -EINVAL;
> + return ret;
> + }
> +
> + if (externally_control) {

By writing

if (!externally_control) {
charger->externally_control = externally_control;
return count;
}

You could greatly reduce indentation level (and readability).

> + int chargers_externally_control = 1;
> +
> + for (i = 0 ; i < desc->num_charger_regulators ; i++) {
> + if ((&desc->charger_regulators[i] != charger)

Parethesis are not needed for the != condition.

> + && !desc->charger_regulators[i].externally_control) {

Wrong indentation for 'if' continuation line, and && should have
been on the previous line.

> + /*
> + * At least, one charger is controlled by
> + * charger-manager
> + */
> + chargers_externally_control = 0;
> + break;
> + }
> + }
> +
> + if (!chargers_externally_control) {
> + if (cm->charger_enabled) {
> + try_charger_enable(charger->cm, false);
> + charger->externally_control
> + = externally_control;
> + try_charger_enable(charger->cm, true);
> + } else
> + charger->externally_control
> + = externally_control;

Since you use multiline 'if', else must have opening braced as
well, i.e.

} else {
....
}

> +
> + } else {
> + dev_warn(cm->dev,
> + "\'%s\' regulator should be controlled "

\ is not needed.

> + "in charger-manager because charger-manager "
> + "must need at least one charger for charging\n",
> + charger->regulator_name);
> + }
> + } else
> + charger->externally_control = externally_control;
> +
> + return count;
> +}
> +
> static int charger_manager_probe(struct platform_device *pdev)
> {
> struct charger_desc *desc = dev_get_platdata(&pdev->dev);
> struct charger_manager *cm;
> int ret = 0, i = 0;
> int j = 0;
> + int chargers_externally_control = 1;
> union power_supply_propval val;
>
> if (g_desc && !rtc_dev && g_desc->rtc_name) {
> @@ -1412,6 +1508,8 @@ static int charger_manager_probe(struct platform_device *pdev)
> for (i = 0 ; i < desc->num_charger_regulators ; i++) {
> struct charger_regulator *charger
> = &desc->charger_regulators[i];
> + char buf[11];
> + char *str;
>
> charger->consumer = regulator_get(&pdev->dev,
> charger->regulator_name);
> @@ -1421,8 +1519,9 @@ static int charger_manager_probe(struct platform_device *pdev)
> ret = -EINVAL;
> goto err_chg_get;
> }
> + charger->cm = cm;
>
> - for (j = 0 ; j < charger->num_cables ; j++) {
> + for (j = 0; j < charger->num_cables; j++) {

While this exact change is technically correct, it does not belong
to this patch.

> struct charger_cable *cable = &charger->cables[j];
>
> ret = charger_extcon_init(cm, cable);
> @@ -1434,6 +1533,71 @@ static int charger_manager_probe(struct platform_device *pdev)
> cable->charger = charger;
> cable->cm = cm;
> }
> +
> + /* Create sysfs entry to control charger(regulator) */
> + snprintf(buf, 10, "charger.%d", i);
> + str = kzalloc(sizeof(char) * (strlen(buf) + 1), GFP_KERNEL);
> + if (!str) {
> + for (i--; i >= 0; i--) {
> + charger = &desc->charger_regulators[i];
> + kfree(charger->attr_g.name);
> + }
> + ret = -ENOMEM;
> +
> + goto err_extcon;
> + }
> + strcpy(str, buf);
> +
> + charger->attrs[0] = &charger->attr_name.attr;
> + charger->attrs[1] = &charger->attr_state.attr;
> + charger->attrs[2] = &charger->attr_externally_control.attr;
> + charger->attrs[3] = NULL;
> + charger->attr_g.name = str;
> + charger->attr_g.attrs = charger->attrs;
> +
> + sysfs_attr_init(&charger->attr_name.attr);
> + charger->attr_name.attr.name = "name";
> + charger->attr_name.attr.mode = 0444;
> + charger->attr_name.show = charger_name_show;
> +
> + sysfs_attr_init(&charger->attr_state.attr);
> + charger->attr_state.attr.name = "state";
> + charger->attr_state.attr.mode = 0444;
> + charger->attr_state.show = charger_state_show;
> +
> + sysfs_attr_init(&charger->attr_externally_control.attr);
> + charger->attr_externally_control.attr.name
> + = "externally_control";
> + charger->attr_externally_control.attr.mode = 0644;
> + charger->attr_externally_control.show
> + = charger_externally_control_show;
> + charger->attr_externally_control.store
> + = charger_externally_control_store;
> +
> + if (!desc->charger_regulators[i].externally_control
> + || !chargers_externally_control) {

wrong || placement (should be on the previous line)

> + chargers_externally_control = 0;
> + }
> + dev_info(&pdev->dev, "\'%s\' regulator's externally_control"

\ is not needed.

> + "is %d\n", charger->regulator_name,
> + charger->externally_control);
> +
> + ret = sysfs_create_group(&cm->charger_psy.dev->kobj,
> + &charger->attr_g);
> + if (ret < 0) {
> + dev_info(&pdev->dev, "Cannot create sysfs entry"
> + "of %s regulator\n",
> + charger->regulator_name);
> + }
> + }
> +
> + if (chargers_externally_control) {
> + dev_err(&pdev->dev, "Cannot register regulator because "
> + "charger-manager must need at least "
> + "one charger for charging battery\n");
> +
> + ret = -EINVAL;
> + goto err_chg_enable;
> }
>
> ret = try_charger_enable(cm, true);
> @@ -1459,6 +1623,14 @@ static int charger_manager_probe(struct platform_device *pdev)
> return 0;
>
> err_chg_enable:
> + for (i = 0 ; i < desc->num_charger_regulators ; i++) {

No spaces before ";".

> + struct charger_regulator *charger
> + = &desc->charger_regulators[i];

Empty line here.

> + struct charger_regulator *charger
> + = &desc->charger_regulators[i];
> + charger = &desc->charger_regulators[i];

One of the assignments is not needed.

So pretty much every line of this patch breaks coding style rules. I fixed
it all myself and applied the patch (since it's pretty late, and I don't
want you to miss the merge window. But double check the final result, it
is inlined down below)

Also, please carefully (re)read Documentation/CodingStyle, and fully
adhere to these standards for any further patch submissions.

Thanks,
Anton.


- - - -
From: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Subject: charger-manager: Add support sysfs entry for charger

This patch add support sysfs entry for each charger(regulator).
Charger-manager use one or more chargers for charging battery but some
charger isn't necessary on specific scenario. So, if some charger isn't
needed, can disable specific charger through 'externally_control' entry
while system is on state and confirm the information(name, state) of
charger.

The list of added sysfs entry
- /sys/class/power_supply/battery/chargers/charger.[index]/name
show name of charger(regulator)
- /sys/class/power_supply/battery/chargers/charger.[index]/state
show either enabled or disabled state of charger
- /sys/class/power_supply/battery/chargers/charger.[index]/externally_control

If 'externally_control' of specific charger is 1, Charger-manager cannot
enable regulator for charging when charger cable is attached and charger
must be maintained with disabled state. If 'externally_control' is zero,
Charger-manager usually can control to enable/disable regulator.

Signed-off-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Signed-off-by: Myungjoo Ham <myungjoo.ham@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>
---
drivers/power/charger-manager.c | 172 ++++++++++++++++++++++++++++++++++
include/linux/power/charger-manager.h | 19 ++++
2 files changed, 191 insertions(+)

diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
index e92ec55..92dfa5c 100644
--- a/drivers/power/charger-manager.c
+++ b/drivers/power/charger-manager.c
@@ -22,6 +22,7 @@
#include <linux/platform_device.h>
#include <linux/power/charger-manager.h>
#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>

static const char * const default_event_names[] = {
[CM_EVENT_UNKNOWN] = "Unknown",
@@ -332,6 +333,9 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
cm->charging_end_time = 0;

for (i = 0 ; i < desc->num_charger_regulators ; i++) {
+ if (desc->charger_regulators[i].externally_control)
+ continue;
+
err = regulator_enable(desc->charger_regulators[i].consumer);
if (err < 0) {
dev_warn(cm->dev,
@@ -348,6 +352,9 @@ static int try_charger_enable(struct charger_manager *cm, bool enable)
cm->charging_end_time = ktime_to_ms(ktime_get());

for (i = 0 ; i < desc->num_charger_regulators ; i++) {
+ if (desc->charger_regulators[i].externally_control)
+ continue;
+
err = regulator_disable(desc->charger_regulators[i].consumer);
if (err < 0) {
dev_warn(cm->dev,
@@ -1217,12 +1224,101 @@ static int charger_extcon_init(struct charger_manager *cm,
return ret;
}

+/* help function of sysfs node to control charger(regulator) */
+static ssize_t charger_name_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct charger_regulator *charger
+ = container_of(attr, struct charger_regulator, attr_name);
+
+ return sprintf(buf, "%s\n", charger->regulator_name);
+}
+
+static ssize_t charger_state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct charger_regulator *charger
+ = container_of(attr, struct charger_regulator, attr_state);
+ int state = 0;
+
+ if (!charger->externally_control)
+ state = regulator_is_enabled(charger->consumer);
+
+ return sprintf(buf, "%s\n", state ? "enabled" : "disabled");
+}
+
+static ssize_t charger_externally_control_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct charger_regulator *charger = container_of(attr,
+ struct charger_regulator, attr_externally_control);
+
+ return sprintf(buf, "%d\n", charger->externally_control);
+}
+
+static ssize_t charger_externally_control_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct charger_regulator *charger
+ = container_of(attr, struct charger_regulator,
+ attr_externally_control);
+ struct charger_manager *cm = charger->cm;
+ struct charger_desc *desc = cm->desc;
+ int i;
+ int ret;
+ int externally_control;
+ int chargers_externally_control = 1;
+
+ ret = sscanf(buf, "%d", &externally_control);
+ if (ret == 0) {
+ ret = -EINVAL;
+ return ret;
+ }
+
+ if (!externally_control) {
+ charger->externally_control = 0;
+ return count;
+ }
+
+ for (i = 0; i < desc->num_charger_regulators; i++) {
+ if (&desc->charger_regulators[i] != charger &&
+ !desc->charger_regulators[i].externally_control) {
+ /*
+ * At least, one charger is controlled by
+ * charger-manager
+ */
+ chargers_externally_control = 0;
+ break;
+ }
+ }
+
+ if (!chargers_externally_control) {
+ if (cm->charger_enabled) {
+ try_charger_enable(charger->cm, false);
+ charger->externally_control = externally_control;
+ try_charger_enable(charger->cm, true);
+ } else {
+ charger->externally_control = externally_control;
+ }
+ } else {
+ dev_warn(cm->dev,
+ "'%s' regulator should be controlled "
+ "in charger-manager because charger-manager "
+ "must need at least one charger for charging\n",
+ charger->regulator_name);
+ }
+
+ return count;
+}
+
static int charger_manager_probe(struct platform_device *pdev)
{
struct charger_desc *desc = dev_get_platdata(&pdev->dev);
struct charger_manager *cm;
int ret = 0, i = 0;
int j = 0;
+ int chargers_externally_control = 1;
union power_supply_propval val;

if (g_desc && !rtc_dev && g_desc->rtc_name) {
@@ -1412,6 +1508,8 @@ static int charger_manager_probe(struct platform_device *pdev)
for (i = 0 ; i < desc->num_charger_regulators ; i++) {
struct charger_regulator *charger
= &desc->charger_regulators[i];
+ char buf[11];
+ char *str;

charger->consumer = regulator_get(&pdev->dev,
charger->regulator_name);
@@ -1421,6 +1519,7 @@ static int charger_manager_probe(struct platform_device *pdev)
ret = -EINVAL;
goto err_chg_get;
}
+ charger->cm = cm;

for (j = 0 ; j < charger->num_cables ; j++) {
struct charger_cable *cable = &charger->cables[j];
@@ -1434,6 +1533,71 @@ static int charger_manager_probe(struct platform_device *pdev)
cable->charger = charger;
cable->cm = cm;
}
+
+ /* Create sysfs entry to control charger(regulator) */
+ snprintf(buf, 10, "charger.%d", i);
+ str = kzalloc(sizeof(char) * (strlen(buf) + 1), GFP_KERNEL);
+ if (!str) {
+ for (i--; i >= 0; i--) {
+ charger = &desc->charger_regulators[i];
+ kfree(charger->attr_g.name);
+ }
+ ret = -ENOMEM;
+
+ goto err_extcon;
+ }
+ strcpy(str, buf);
+
+ charger->attrs[0] = &charger->attr_name.attr;
+ charger->attrs[1] = &charger->attr_state.attr;
+ charger->attrs[2] = &charger->attr_externally_control.attr;
+ charger->attrs[3] = NULL;
+ charger->attr_g.name = str;
+ charger->attr_g.attrs = charger->attrs;
+
+ sysfs_attr_init(&charger->attr_name.attr);
+ charger->attr_name.attr.name = "name";
+ charger->attr_name.attr.mode = 0444;
+ charger->attr_name.show = charger_name_show;
+
+ sysfs_attr_init(&charger->attr_state.attr);
+ charger->attr_state.attr.name = "state";
+ charger->attr_state.attr.mode = 0444;
+ charger->attr_state.show = charger_state_show;
+
+ sysfs_attr_init(&charger->attr_externally_control.attr);
+ charger->attr_externally_control.attr.name
+ = "externally_control";
+ charger->attr_externally_control.attr.mode = 0644;
+ charger->attr_externally_control.show
+ = charger_externally_control_show;
+ charger->attr_externally_control.store
+ = charger_externally_control_store;
+
+ if (!desc->charger_regulators[i].externally_control ||
+ !chargers_externally_control) {
+ chargers_externally_control = 0;
+ }
+ dev_info(&pdev->dev, "'%s' regulator's externally_control"
+ "is %d\n", charger->regulator_name,
+ charger->externally_control);
+
+ ret = sysfs_create_group(&cm->charger_psy.dev->kobj,
+ &charger->attr_g);
+ if (ret < 0) {
+ dev_info(&pdev->dev, "Cannot create sysfs entry"
+ "of %s regulator\n",
+ charger->regulator_name);
+ }
+ }
+
+ if (chargers_externally_control) {
+ dev_err(&pdev->dev, "Cannot register regulator because "
+ "charger-manager must need at least "
+ "one charger for charging battery\n");
+
+ ret = -EINVAL;
+ goto err_chg_enable;
}

ret = try_charger_enable(cm, true);
@@ -1459,6 +1623,14 @@ static int charger_manager_probe(struct platform_device *pdev)
return 0;

err_chg_enable:
+ for (i = 0; i < desc->num_charger_regulators; i++) {
+ struct charger_regulator *charger;
+
+ charger = &desc->charger_regulators[i];
+ sysfs_remove_group(&cm->charger_psy.dev->kobj,
+ &charger->attr_g);
+ kfree(charger->attr_g.name);
+ }
err_extcon:
for (i = 0 ; i < desc->num_charger_regulators ; i++) {
struct charger_regulator *charger
diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
index a7b388e..0e86840 100644
--- a/include/linux/power/charger-manager.h
+++ b/include/linux/power/charger-manager.h
@@ -109,24 +109,43 @@ struct charger_cable {
* struct charger_regulator
* @regulator_name: the name of regulator for using charger.
* @consumer: the regulator consumer for the charger.
+ * @externally_control:
+ * Set if the charger-manager cannot control charger,
+ * the charger will be maintained with disabled state.
* @cables:
* the array of charger cables to enable/disable charger
* and set current limit according to constratint data of
* struct charger_cable if only charger cable included
* in the array of charger cables is attached/detached.
* @num_cables: the number of charger cables.
+ * @attr_g: Attribute group for the charger(regulator)
+ * @attr_name: "name" sysfs entry
+ * @attr_state: "state" sysfs entry
+ * @attr_externally_control: "externally_control" sysfs entry
+ * @attrs: Arrays pointing to attr_name/state/externally_control for attr_g
*/
struct charger_regulator {
/* The name of regulator for charging */
const char *regulator_name;
struct regulator *consumer;

+ /* charger never on when system is on */
+ int externally_control;
+
/*
* Store constraint information related to current limit,
* each cable have different condition for charging.
*/
struct charger_cable *cables;
int num_cables;
+
+ struct attribute_group attr_g;
+ struct device_attribute attr_name;
+ struct device_attribute attr_state;
+ struct device_attribute attr_externally_control;
+ struct attribute *attrs[4];
+
+ struct charger_manager *cm;
};

/**
--
1.7.11.5

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