The fusb302 port-controller relies on an external device doing USB2
charger-type detection.
The Intel Whiskey Cove PMIC with which the fusb302 is combined on some
X86/ACPI platforms already has a charger-type detection driver which
uses extcon to communicate the detected charger-type.
Rather then inventing a new API for USB2 charger-type detection
specifically for use with the tcpm code, this commit simply re-uses the
existing extcon API and uses that do USB2 charger detection.
Note that the "fcs,extcon-name" property name is only for kernel internal
use by X86/ACPI platform code and as such is NOT documented in
the fusb302 devicetree bindings.
Cc: "Yueyao (Nathan) Zhu" <yueyao@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
-Put extcon code directly in fusb302.c rather then introducing helpers
which are only used by fusb302.c
Changes in v3:
-Improve commit message
---
drivers/staging/typec/fusb302/fusb302.c | 49 +++++++++++++++++++++++++++++++++
1 file changed, 49 insertions(+)
diff --git a/drivers/staging/typec/fusb302/fusb302.c b/drivers/staging/typec/fusb302/fusb302.c
index 675161cf4f3a..6f007f66d597 100644
--- a/drivers/staging/typec/fusb302/fusb302.c
+++ b/drivers/staging/typec/fusb302/fusb302.c
@@ -17,6 +17,7 @@
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/errno.h>
+#include <linux/extcon.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
@@ -96,6 +97,7 @@ struct fusb302_chip {
int gpio_int_n;
int gpio_int_n_irq;
+ struct extcon_dev *extcon;
struct workqueue_struct *wq;
struct delayed_work bc_lvl_handler;
@@ -516,6 +518,38 @@ static int tcpm_get_vbus(struct tcpc_dev *dev)
return ret;
}
+static int tcpm_get_current_limit(struct tcpc_dev *dev)
+{
+ struct fusb302_chip *chip = container_of(dev, struct fusb302_chip,
+ tcpc_dev);
+ int current_limit = 0;
+ unsigned long timeout;
+
+ if (!chip->extcon)
+ return 0;
+
+ /*
+ * USB2 Charger detection may still be in progress when we get here,
+ * this can take upto 600ms, wait 800ms max.
+ */
+ timeout = jiffies + msecs_to_jiffies(800);
+ do {
+ if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_SDP) == 1)
+ current_limit = 500;
+
+ if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_CDP) == 1 ||
+ extcon_get_state(chip->extcon, EXTCON_CHG_USB_ACA) == 1)
+ current_limit = 1500;
+
+ if (extcon_get_state(chip->extcon, EXTCON_CHG_USB_DCP) == 1)
+ current_limit = 2000;
+
+ msleep(50);
+ } while (current_limit == 0 && time_before(jiffies, timeout));
+
+ return current_limit;
+}
+
static int fusb302_set_cc_pull(struct fusb302_chip *chip,
bool pull_up, bool pull_down)
{
@@ -1201,6 +1235,7 @@ static void init_tcpc_dev(struct tcpc_dev *fusb302_tcpc_dev)
{
fusb302_tcpc_dev->init = tcpm_init;
fusb302_tcpc_dev->get_vbus = tcpm_get_vbus;
+ fusb302_tcpc_dev->get_current_limit = tcpm_get_current_limit;
fusb302_tcpc_dev->set_cc = tcpm_set_cc;
fusb302_tcpc_dev->get_cc = tcpm_get_cc;
fusb302_tcpc_dev->set_polarity = tcpm_set_polarity;
@@ -1685,6 +1720,7 @@ static int fusb302_probe(struct i2c_client *client,
struct fusb302_chip *chip;
struct i2c_adapter *adapter;
struct device *dev = &client->dev;
+ const char *name;
int ret = 0;
u32 v;
@@ -1717,6 +1753,19 @@ static int fusb302_probe(struct i2c_client *client,
if (!device_property_read_u32(dev, "fcs,operating-sink-microwatt", &v))
chip->tcpc_config.operating_snk_mw = v / 1000;
+ /*
+ * Devicetree platforms should get extcon via phandle (not yet
+ * supported). On ACPI platforms, we get the name from a device prop.
+ * This device prop is for kernel internal use only and is expected
+ * to be set by the platform code which also registers the i2c client
+ * for the fusb302.
+ */
+ if (device_property_read_string(dev, "fcs,extcon-name", &name) == 0) {
+ chip->extcon = extcon_get_extcon_dev(name);
+ if (!chip->extcon)
+ return -EPROBE_DEFER;
+ }
+
ret = fusb302_debugfs_init(chip);
if (ret < 0)
return ret;
--
2.13.4
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