Re: [PATCHv8 2/4] power_supply: Introduce generic psy charging driver

[Pavel Machek <pavel@ucw.cz>]

Hi!

> The Power Supply charging driver connects multiple subsystems
> to do charging in a generic way. The subsystems involves power_supply,
> thermal and battery communication subsystems (1wire).With this the charging is
> handled in a generic way.

" " after ".", please.
> +
> +The Power Supply charging driver connects multiple subsystems
> +to do charging in a generic way. The subsystems involves power_supply,
> +thermal and battery communication subsystems (1wire).With this the charging is

Here too.



> +
> +The driver introduces different new features - Battery Identification
> +interfaces, pluggable charging algorithms, charger cable arbitrations etc.
> +
> +In existing driver implementations the charging is done based on the static
> +battery characteristics. This is done at the boot time by passing the battery
> +properties (max_voltage, capacity) etc. as a platform data to the

-> (max_voltage, capacity, etc.)

> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -14,6 +14,14 @@ config POWER_SUPPLY_DEBUG
>  	  Say Y here to enable debugging messages for power supply class
>  	  and drivers.
>  
> +config POWER_SUPPLY_CHARGER
> +	bool "Power Supply Charger"
> +	help
> +	  Say Y here to enable the power supply charging control driver. Charging
> +	  control supports charging in a generic way. This allows the charger
> +	  drivers to keep the charging logic outside and the charger driver
> +	  just need to abstract the charger hardware.
> +

Umm. This is not too helpful for our users.

> +struct psy_charger_context {
> +	bool is_usb_cable_evt_reg;
> +	int psyc_cnt;
> +	int batt_status;
> +	/* cache battery and charger properties */
> +	struct list_head chrgr_cache_lst;
> +	struct list_head batt_cache_lst;
> +	struct mutex event_lock;
> +	struct list_head event_queue;
> +	struct psy_batt_chrg_prof batt_property;
> +	wait_queue_head_t wait_chrg_enable;
> +	spinlock_t battid_spinlock;
> +	spinlock_t event_queue_lock;
> +	struct work_struct event_work;
> +};
> +
> +struct charger_cable {
> +	struct psy_cable_props cable_props;
> +	enum psy_charger_cable_type psy_cable_type;
> +};
> +
> +static struct psy_charger_context psy_chrgr;

You still miss some wovels here. Sometimes it imakes it unlear: 
chrg is charge? charger?


> +static inline bool psy_is_charger_prop_changed(struct psy_charger_props prop,
> +		struct psy_charger_props cache_prop)
> +{
> +	/* if online/prsent/health/is_charging is changed, then return true */

Typo - present.

> +static inline void cache_chrgr_prop(struct psy_charger_props *chrgr_prop_new)
> +{
> +	struct psy_charger_props *chrgr_cache;
> +
> +	list_for_each_entry(chrgr_cache, &psy_chrgr.chrgr_cache_lst, node) {
> +		if (!strcmp(chrgr_cache->name, chrgr_prop_new->name))
> +			goto update_props;
> +	}

Interesting use of goto. Maybe update_properties should be separate function?

> +update_props:
> +	chrgr_cache->is_charging = chrgr_prop_new->is_charging;
> +	chrgr_cache->online = chrgr_prop_new->online;
> +	chrgr_cache->health = chrgr_prop_new->health;
> +	chrgr_cache->present = chrgr_prop_new->present;
> +	chrgr_cache->cable = chrgr_prop_new->cable;
> +	chrgr_cache->tstamp = chrgr_prop_new->tstamp;
> +	chrgr_cache->psyc = chrgr_prop_new->psyc;
> +}
> +
> +	chrgr_prop.psyc = chrgr_prop_cache.psyc;
> +	cache_chrgr_prop(&chrgr_prop);
> +	return true;
> +}
> +static void cache_successive_samples(long *sample_array, long new_sample)
> +{

Add empty line between the functions.

> +static inline void cache_bat_prop(struct psy_batt_props *bat_prop_new)
> +{
> +	struct psy_batt_props *bat_cache;
> +
> +	/*
> +	*  Find entry in cache list. If an entry is located update
> +	*  the existing entry else create new entry in the list
> +	*/
> +	list_for_each_entry(bat_cache, &psy_chrgr.batt_cache_lst, node) {
> +		if (!strcmp(bat_cache->name, bat_prop_new->name))
> +			goto update_props;
> +	}
> +
> +	bat_cache = kzalloc(sizeof(*bat_cache), GFP_KERNEL);

What is it with all the caching? Is it good idea to have caches
indexed by strings? Can't you go without caching, or attach caches to
some structure? Interesting goto again.

> +static inline void get_cur_bat_prop(struct power_supply *psy,
> +				    struct psy_batt_props *bat_prop)
> +{
> +	struct psy_batt_props bat_prop_cache;
> +	int ret;
> +
> +	bat_prop->name = psy->name;
> +	bat_prop->voltage_now = PSY_VOLTAGE_OCV(psy) / 1000;

Not sure what OCV means...

> +static inline bool is_supplied_to_has_ext_pwr_changed(struct power_supply *psy)
> +{
> +	int i;
> +	struct power_supply *psb;
> +	bool is_pwr_changed_defined = true;
> +
> +	for (i = 0; i < psy->num_supplicants; i++) {
> +		psb =
> +		    power_supply_get_by_name(psy->
> +					     supplied_to[i]);

You can do it on one line, right?

> +		if (psb && !psb->external_power_changed)
> +			is_pwr_changed_defined &= false;

WTF?

> +static int get_supplied_by_list(struct power_supply *psy,
> +				struct power_supply *psy_lst[])
> +{
> +	struct class_dev_iter iter;
> +	struct device *dev;
> +	struct power_supply *pst;
> +	int cnt = 0, i, j;
> +
> +	if (!psy_is_battery(psy))
> +		return 0;
> +
> +	/* Identify chargers which are supplying power to the battery */
> +	class_dev_iter_init(&iter, power_supply_class, NULL, NULL);
> +	while ((dev = class_dev_iter_next(&iter))) {
> +		pst = (struct power_supply *)dev_get_drvdata(dev);
> +		if (!psy_is_charger(pst))
> +			continue;
> +		for (i = 0; i < pst->num_supplicants; i++) {
> +			if (!strcmp(pst->supplied_to[i], psy->name))
> +				psy_lst[cnt++] = pst;
> +		}

Awful lot of string compares around.


> +	/* sort based on priority. 0 has the highest priority  */
> +	for (i = 0; i < cnt; ++i)
> +		for (j = 0; j < cnt; ++j)
> +			if (psy_prioirty(psy_lst[j]) > psy_prioirty(psy_lst[i]))
> +				swap(psy_lst[j], psy_lst[i]);
> +

WTF? Bubble sort in kernel?

priority is misspelled...

Does it really be so complex? Dynamically allocated caches, name
compares everywhere?


									Pavel

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