Some type-c port-controllers, such as the fusb302 port-controller, rely
on an external device doing USB2 charger-type detection.
Existing PMIC (and charger) drivers already use extcon to communicate the
detected charger-type from the PMIC (extcon) driver to the charger driver.
Rather then inventing a new API for USB2 charger-type detection
specifically for use with the tcpm code, lets simply re-use the existing
support. This will also allow re-using existing PMIC extcon drivers such
as the axp288 and Intel Whiskey Cove drivers as is on devices where these
are combined with a fusb302 (or in the future another port-controller
which relies on external USB2 charger-type detection).
This commit adds a helper function which tcpc drivers can use to easily
hook into existing PMIC extcon drivers for USB2 charger-type detection:
int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc);
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
drivers/staging/typec/tcpm.c | 40 ++++++++++++++++++++++++++++++++++++++++
drivers/staging/typec/tcpm.h | 6 ++++++
2 files changed, 46 insertions(+)
diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index 9f5adace4309..06bb0e640bcf 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -16,6 +16,7 @@
#include <linux/completion.h>
#include <linux/debugfs.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -3532,6 +3533,45 @@ void tcpm_unregister_port(struct tcpm_port *port)
}
EXPORT_SYMBOL_GPL(tcpm_unregister_port);
+/* Generic (helper) implementations for some tcpc_dev callbacks */
+int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc)
+{
+ struct extcon_dev *extcon = tcpc->usb2_extcon;
+ int current_limit = 0;
+ unsigned long timeout;
+
+ if (!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(extcon, EXTCON_CHG_USB_SDP) == 1) {
+ current_limit = 500;
+ break;
+ }
+
+ if (extcon_get_state(extcon, EXTCON_CHG_USB_CDP) == 1 ||
+ extcon_get_state(extcon, EXTCON_CHG_USB_ACA) == 1) {
+ current_limit = 1500;
+ break;
+ }
+
+ if (extcon_get_state(extcon, EXTCON_CHG_USB_DCP) == 1) {
+ current_limit = 2000;
+ break;
+ }
+
+ msleep(50);
+ } while (time_before(jiffies, timeout));
+
+ return current_limit;
+}
+EXPORT_SYMBOL_GPL(tcpm_get_usb2_current_limit_extcon);
+
MODULE_AUTHOR("Guenter Roeck <groeck@xxxxxxxxxxxx>");
MODULE_DESCRIPTION("USB Type-C Port Manager");
MODULE_LICENSE("GPL");
diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h
index 01b7d89379a3..35e8c1e7dba0 100644
--- a/drivers/staging/typec/tcpm.h
+++ b/drivers/staging/typec/tcpm.h
@@ -16,6 +16,7 @@
#define __LINUX_USB_TCPM_H
#include <linux/bitops.h>
+#include <linux/extcon.h>
#include <linux/usb/typec.h>
#include "pd.h"
@@ -126,6 +127,8 @@ struct tcpc_dev {
int (*pd_transmit)(struct tcpc_dev *dev, enum tcpm_transmit_type type,
const struct pd_message *msg);
struct tcpc_mux_dev *mux;
+ /* Used by tcpm_get_usb2_current_limit_extcon helpers */
+ struct extcon_dev *usb2_extcon;
};
struct tcpm_port;
@@ -151,4 +154,7 @@ void tcpm_pd_transmit_complete(struct tcpm_port *port,
void tcpm_pd_hard_reset(struct tcpm_port *port);
void tcpm_tcpc_reset(struct tcpm_port *port);
+/* Generic (helper) implementations for some tcpc_dev callbacks */
+int tcpm_get_usb2_current_limit_extcon(struct tcpc_dev *tcpc);
+
#endif /* __LINUX_USB_TCPM_H */
--
2.13.3
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