diff mbox series

[v19,4/4] power: wm831x_power: Support USB charger current limit management

Message ID c785b7bd9ad81bffa5c7311e52b6eda46c16f310.1487578977.git.baolin.wang@linaro.org
State Superseded
Headers show
Series Introduce usb charger framework to deal with the usb gadget power negotation | expand

Commit Message

(Exiting) Baolin Wang Feb. 20, 2017, 8:51 a.m. UTC
Integrate with the newly added USB charger interface to limit the current
we draw from the USB input based on the input device configuration
identified by the USB stack, allowing us to charge more quickly from high
current inputs without drawing more current than specified from others.

Signed-off-by: Mark Brown <broonie@kernel.org>

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

Acked-by: Lee Jones <lee.jones@linaro.org>

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>

Acked-by: Peter Chen <peter.chen@freescale.com>

Acked-by: Sebastian Reichel <sre@kernel.org>

---
 drivers/power/supply/wm831x_power.c |   63 +++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

-- 
1.7.9.5
diff mbox series

Patch

diff --git a/drivers/power/supply/wm831x_power.c b/drivers/power/supply/wm831x_power.c
index 7082301..b5f1652 100644
--- a/drivers/power/supply/wm831x_power.c
+++ b/drivers/power/supply/wm831x_power.c
@@ -13,6 +13,7 @@ 
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
 #include <linux/slab.h>
+#include <linux/usb/charger.h>
 
 #include <linux/mfd/wm831x/core.h>
 #include <linux/mfd/wm831x/auxadc.h>
@@ -31,6 +32,8 @@  struct wm831x_power {
 	char usb_name[20];
 	char battery_name[20];
 	bool have_battery;
+	struct usb_charger *usb_charger;
+	struct notifier_block usb_notify;
 };
 
 static int wm831x_power_check_online(struct wm831x *wm831x, int supply,
@@ -125,6 +128,42 @@  static int wm831x_usb_get_prop(struct power_supply *psy,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 };
 
+/* In milliamps */
+static const unsigned int wm831x_usb_limits[] = {
+	0,
+	2,
+	100,
+	500,
+	900,
+	1500,
+	1800,
+	550,
+};
+
+static int wm831x_usb_limit_change(struct notifier_block *nb,
+				   unsigned long limit, void *data)
+{
+	struct wm831x_power *wm831x_power = container_of(nb,
+							 struct wm831x_power,
+							 usb_notify);
+
+	/* Find the highest supported limit */
+	best = 0;
+	for (i = 0; i < ARRAY_SIZE(wm831x_usb_limits); i++) {
+		if (limit >= wm831x_usb_limits[i] &&
+		    wm831x_usb_limits[best] < wm831x_usb_limits[i])
+			best = i;
+	}
+
+	dev_dbg(wm831x_power->wm831x->dev,
+		"Limiting USB current to %umA", wm831x_usb_limits[best]);
+
+	wm831x_set_bits(wm831x_power->wm831x, WM831X_POWER_STATE,
+		        WM831X_USB_ILIM_MASK, best);
+
+	return 0;
+}
+
 /*********************************************************************
  *		Battery properties
  *********************************************************************/
@@ -607,8 +646,26 @@  static int wm831x_power_probe(struct platform_device *pdev)
 		}
 	}
 
+	power->usb_charger = usb_charger_get_instance();
+	if (IS_ERR(power->usb_charger)) {
+		ret = PTR_ERR(power->usb_charger);
+		dev_err(&pdev->dev, "Failed to find USB gadget: %d\n", ret);
+		goto err_bat_irq;
+	}
+
+	power->usb_notify.notifier_call = wm831x_usb_limit_change;
+
+	ret = usb_charger_register_notify(power->usb_charger,
+					  &power->usb_notify);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
+		goto err_usb_charger;
+	}
+
 	return ret;
 
+err_usb_charger:
+	/* put_device on charger */
 err_bat_irq:
 	--i;
 	for (; i >= 0; i--) {
@@ -637,6 +694,12 @@  static int wm831x_power_remove(struct platform_device *pdev)
 	struct wm831x *wm831x = wm831x_power->wm831x;
 	int irq, i;
 
+	if (wm831x_power->usb_charger) {
+		usb_charger_unregister_notify(wm831x_power->usb_charger,
+					      &wm831x_power->usb_notify);
+		/* Free charger */
+	}
+
 	for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {
 		irq = wm831x_irq(wm831x, 
 				 platform_get_irq_byname(pdev,