usb: dwc3: add a power supply for current control

Currently, VBUS draw callback does no action when the
generic PHYs are used. This patch adds an additional
path to control charging current through power supply
interface.

Signed-off-by: Ray Chi <raychi@google.com>
Link: https://lore.kernel.org/r/20210222115149.3606776-2-raychi@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index f2448d0..d15f065 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1238,6 +1238,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
        u8                      rx_max_burst_prd;
        u8                      tx_thr_num_pkt_prd;
        u8                      tx_max_burst_prd;
+       const char              *usb_psy_name;
+       int                     ret;
 
        /* default to highest possible threshold */
        lpm_nyet_threshold = 0xf;
@@ -1263,6 +1265,13 @@ static void dwc3_get_properties(struct dwc3 *dwc)
        else
                dwc->sysdev = dwc->dev;
 
+       ret = device_property_read_string(dev, "usb-psy-name", &usb_psy_name);
+       if (ret >= 0) {
+               dwc->usb_psy = power_supply_get_by_name(usb_psy_name);
+               if (!dwc->usb_psy)
+                       dev_err(dev, "couldn't get usb power supply\n");
+       }
+
        dwc->has_lpm_erratum = device_property_read_bool(dev,
                                "snps,has-lpm-erratum");
        device_property_read_u8(dev, "snps,lpm-nyet-threshold",
@@ -1619,6 +1628,9 @@ disable_clks:
 assert_reset:
        reset_control_assert(dwc->reset);
 
+       if (!dwc->usb_psy)
+               power_supply_put(dwc->usb_psy);
+
        return ret;
 }
 
@@ -1641,6 +1653,9 @@ static int dwc3_remove(struct platform_device *pdev)
        dwc3_free_event_buffers(dwc);
        dwc3_free_scratch_buffers(dwc);
 
+       if (!dwc->usb_psy)
+               power_supply_put(dwc->usb_psy);
+
        return 0;
 }
 

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 052b20d..6708fdf 100644 (file)
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -30,6 +30,8 @@
 
 #include <linux/phy/phy.h>
 
+#include <linux/power_supply.h>
+
 #define DWC3_MSG_MAX   500
 
 /* Global constants */
@@ -1125,6 +1127,8 @@ struct dwc3 {
        struct usb_role_switch  *role_sw;
        enum usb_dr_mode        role_switch_default_mode;
 
+       struct power_supply     *usb_psy;
+
        u32                     fladj;
        u32                     irq_gadget;
        u32                     otg_irq;