[PATCH v2 07/14] staging: typec: fusb302: Export current-limit through a power_supply class dev

From: Hans de Goede
Date: Tue Aug 15 2017 - 16:06:03 EST


The fusb302 Type-C port-controller cannot control the current-limit
directly, so we need to exported the limit so that another driver
(e.g. the charger driver) can pick the limit up and configure the
system accordingly.

The power-supply subsys already provides infrastructure for this,
power-supply devices have the notion of being supplied by another
power-supply and have properties through which we can export the
current-limit.

Register a power_supply and export the current-limit through the
power_supply's current-max property.

Cc: "Yueyao (Nathan) Zhu" <yueyao@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
-Put the psy class device code directly in fusb302.c rather then introducing
helpers which are only used by fusb302.c
-Add an online property to the psy so that upower does not mistake it for a
second battery in the system
---
drivers/staging/typec/fusb302/Kconfig | 2 +-
drivers/staging/typec/fusb302/fusb302.c | 63 +++++++++++++++++++++++++++++++--
2 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/typec/fusb302/Kconfig b/drivers/staging/typec/fusb302/Kconfig
index fce099f..48a4f2f 100644
--- a/drivers/staging/typec/fusb302/Kconfig
+++ b/drivers/staging/typec/fusb302/Kconfig
@@ -1,6 +1,6 @@
config TYPEC_FUSB302
tristate "Fairchild FUSB302 Type-C chip driver"
- depends on I2C
+ depends on I2C && POWER_SUPPLY
help
The Fairchild FUSB302 Type-C chip driver that works with
Type-C Port Controller Manager to provide USB PD and USB
diff --git a/drivers/staging/typec/fusb302/fusb302.c b/drivers/staging/typec/fusb302/fusb302.c
index 870f8078..36fde36 100644
--- a/drivers/staging/typec/fusb302/fusb302.c
+++ b/drivers/staging/typec/fusb302/fusb302.c
@@ -28,6 +28,7 @@
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
+#include <linux/power_supply.h>
#include <linux/proc_fs.h>
#include <linux/regulator/consumer.h>
#include <linux/sched/clock.h>
@@ -108,6 +109,11 @@ struct fusb302_chip {
/* lock for sharing chip states */
struct mutex lock;

+ /* psy + psy status */
+ struct power_supply *psy;
+ u32 current_limit;
+ u32 supply_voltage;
+
/* chip status */
enum toggling_mode toggling_mode;
enum src_current_status src_current_status;
@@ -876,11 +882,13 @@ static int tcpm_set_vbus(struct tcpc_dev *dev, bool on, bool charge)
chip->vbus_on = on;
fusb302_log(chip, "vbus := %s", on ? "On" : "Off");
}
- if (chip->charge_on == charge)
+ if (chip->charge_on == charge) {
fusb302_log(chip, "charge is already %s",
charge ? "On" : "Off");
- else
+ } else {
chip->charge_on = charge;
+ power_supply_changed(chip->psy);
+ }

done:
mutex_unlock(&chip->lock);
@@ -896,6 +904,11 @@ static int tcpm_set_current_limit(struct tcpc_dev *dev, u32 max_ma, u32 mv)
fusb302_log(chip, "current limit: %d ma, %d mv (not implemented)",
max_ma, mv);

+ chip->supply_voltage = mv;
+ chip->current_limit = max_ma;
+
+ power_supply_changed(chip->psy);
+
return 0;
}

@@ -1681,6 +1694,43 @@ static irqreturn_t fusb302_irq_intn(int irq, void *dev_id)
return IRQ_HANDLED;
}

+static int fusb302_psy_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct fusb302_chip *chip = power_supply_get_drvdata(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ val->intval = chip->charge_on;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = chip->supply_voltage * 1000; /* mV -> ÂV */
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_MAX:
+ val->intval = chip->current_limit * 1000; /* mA -> ÂA */
+ break;
+ default:
+ return -ENODATA;
+ }
+
+ return 0;
+}
+
+static enum power_supply_property fusb302_psy_properties[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CURRENT_MAX,
+};
+
+const struct power_supply_desc fusb302_psy_desc = {
+ .name = "fusb302-typec-source",
+ .type = POWER_SUPPLY_TYPE_USB_TYPE_C,
+ .properties = fusb302_psy_properties,
+ .num_properties = ARRAY_SIZE(fusb302_psy_properties),
+ .get_property = fusb302_psy_get_property,
+};
+
static int init_gpio(struct fusb302_chip *chip)
{
struct device_node *node;
@@ -1720,6 +1770,7 @@ static int fusb302_probe(struct i2c_client *client,
struct fusb302_chip *chip;
struct i2c_adapter *adapter;
struct device *dev = &client->dev;
+ struct power_supply_config cfg = {};
const char *name;
int ret = 0;
u32 val;
@@ -1766,6 +1817,14 @@ static int fusb302_probe(struct i2c_client *client,
return -EPROBE_DEFER;
}

+ cfg.drv_data = chip;
+ chip->psy = devm_power_supply_register(dev, &fusb302_psy_desc, &cfg);
+ if (IS_ERR(chip->psy)) {
+ ret = PTR_ERR(chip->psy);
+ dev_err(chip->dev, "Error registering power-supply: %d\n", ret);
+ return ret;
+ }
+
ret = fusb302_debugfs_init(chip);
if (ret < 0)
return ret;
--
2.9.4