On Fri, 14 Aug 2015, Baolin Wang wrote:
> 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 <broo...@kernel.org>
> Signed-off-by: Baolin Wang <baolin.w...@linaro.org>
> ---
> drivers/power/wm831x_power.c | 69
> ++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/wm831x/pdata.h | 3 ++
Acked-by: Lee Jones <lee.jo...@linaro.org>
> 2 files changed, 72 insertions(+)
>
> diff --git a/drivers/power/wm831x_power.c b/drivers/power/wm831x_power.c
> index db11ae6..72c661f 100644
> --- a/drivers/power/wm831x_power.c
> +++ b/drivers/power/wm831x_power.c
> @@ -13,6 +13,7 @@
> #include <linux/platform_device.h>
> #include <linux/power_supply.h>
> #include <linux/slab.h>
> +#include <linux/usb/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 +128,43 @@ static enum power_supply_property wm831x_usb_props[] = {
> POWER_SUPPLY_PROP_VOLTAGE_NOW,
> };
>
> +/* In miliamps */
> +static 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);
> + int i, best;
> +
> + /* 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 %dmA", wm831x_usb_limits[best]);
> +
> + wm831x_set_bits(wm831x_power->wm831x, WM831X_POWER_STATE,
> + WM831X_USB_ILIM_MASK, best);
> +
> + return 0;
> +}
> +
> /*********************************************************************
> * Battery properties
> *********************************************************************/
> @@ -606,8 +646,31 @@ static int wm831x_power_probe(struct platform_device
> *pdev)
> }
> }
>
> + if (wm831x_pdata && wm831x_pdata->usb_gadget) {
> + power->usb_charger =
> + usb_charger_find_by_name(wm831x_pdata->usb_gadget);
> + 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:
> + usb_charger_put(power->usb_charger);
> err_bat_irq:
> --i;
> for (; i >= 0; i--) {
> @@ -637,6 +700,12 @@ 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);
> + usb_charger_put(wm831x_power->usb_charger);
> + }
> +
> for (i = 0; i < ARRAY_SIZE(wm831x_bat_irqs); i++) {
> irq = wm831x_irq(wm831x,
> platform_get_irq_byname(pdev,
> diff --git a/include/linux/mfd/wm831x/pdata.h
> b/include/linux/mfd/wm831x/pdata.h
> index dcc9631..5af8399 100644
> --- a/include/linux/mfd/wm831x/pdata.h
> +++ b/include/linux/mfd/wm831x/pdata.h
> @@ -126,6 +126,9 @@ struct wm831x_pdata {
> /** The driver should initiate a power off sequence during shutdown */
> bool soft_shutdown;
>
> + /** dev_name of USB charger gadget to integrate with */
> + const char *usb_gadget;
> +
> int irq_base;
> int gpio_base;
> int gpio_defaults[WM831X_GPIO_NUM];
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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