usb: gadget: rcar: Add support for reset controller

Some Renesas SoCs, such as the RZ/G2L, require the USBHS core to
be explicitly deasserted from reset before register access is
possible.

Update the OTG probe to handle a bulk reset controller. To maintain
hardware stability, the reset is deasserted after clocks are
enabled in probe(), and asserted before clocks are disabled
in remove().

Update the error paths in probe to ensures clocks are disabled
if the reset initialization fails.

Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Michele Bisogno <micbis.openwrt@gmail.com>

diff --git a/drivers/usb/gadget/rcar/common.c b/drivers/usb/gadget/rcar/common.c
index d40d6736a54cc16ab0b2bfd0447142da4024fe4f..2bf0dcff393264668da5d0a16ddaf54b3a5143f3 100644 (file)
--- a/drivers/usb/gadget/rcar/common.c
+++ b/drivers/usb/gadget/rcar/common.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <reset.h>
 #include <usb.h>
 
 #include "common.h"
@@ -290,6 +291,9 @@ struct usbhs_priv_otg_data {
        void __iomem            *base;
        void __iomem            *phybase;
 
+       struct clk_bulk clk_bulk;
+       struct reset_ctl_bulk reset_bulk;
+
        struct platform_device  usbhs_dev;
        struct usbhs_priv       usbhs_priv;
 
@@ -355,8 +359,10 @@ static int usbhs_udc_otg_gadget_handle_interrupts(struct udevice *dev)
        return 0;
 }
 
-static int usbhs_probe(struct usbhs_priv *priv)
+static int usbhs_probe(struct udevice *dev)
 {
+       struct usbhs_priv_otg_data *otg_priv = dev_get_priv(dev);
+       struct usbhs_priv *priv = &otg_priv->usbhs_priv;
        int ret;
 
        priv->dparam.type = USBHS_TYPE_RCAR_GEN3;
@@ -396,34 +402,41 @@ static int usbhs_udc_otg_probe(struct udevice *dev)
 {
        struct usbhs_priv_otg_data *priv = dev_get_priv(dev);
        struct usb_gadget *gadget;
-       struct clk_bulk clk_bulk;
        int ret = -EINVAL;
 
        priv->base = dev_read_addr_ptr(dev);
        if (!priv->base)
                return -EINVAL;
 
-       ret = clk_get_bulk(dev, &clk_bulk);
+       ret = clk_get_bulk(dev, &priv->clk_bulk);
        if (ret)
                return ret;
 
-       ret = clk_enable_bulk(&clk_bulk);
+       ret = clk_enable_bulk(&priv->clk_bulk);
        if (ret)
-               return ret;
+               goto err_clk_enable;
+
+       ret = reset_get_bulk(dev, &priv->reset_bulk);
+       if (ret)
+               goto err_clk;
+
+       ret = reset_deassert_bulk(&priv->reset_bulk);
+       if (ret)
+               goto err_reset_deassert;
 
        clrsetbits_le32(priv->base + UGCTRL2, UGCTRL2_USB0SEL_MASK, UGCTRL2_USB0SEL_EHCI);
        clrsetbits_le16(priv->base + LPSTS, LPSTS_SUSPM, LPSTS_SUSPM);
 
        ret = generic_setup_phy(dev, &priv->phy, 0, PHY_MODE_USB_OTG, 1);
        if (ret)
-               goto err_clk;
+               goto err_reset;
 
        priv->phybase = dev_read_addr_ptr(priv->phy.dev);
 
        priv->usbhs_priv.pdev = &priv->usbhs_dev;
        priv->usbhs_priv.base = priv->base;
        priv->usbhs_dev.dev.driver_data = &priv->usbhs_priv;
-       ret = usbhs_probe(&priv->usbhs_priv);
+       ret = usbhs_probe(dev);
        if (ret < 0)
                goto err_phy;
 
@@ -439,8 +452,15 @@ static int usbhs_udc_otg_probe(struct udevice *dev)
 
 err_phy:
        generic_shutdown_phy(&priv->phy);
+err_reset:
+       reset_assert_bulk(&priv->reset_bulk);
+err_reset_deassert:
+       reset_release_bulk(&priv->reset_bulk);
 err_clk:
-       clk_disable_bulk(&clk_bulk);
+       clk_disable_bulk(&priv->clk_bulk);
+err_clk_enable:
+       clk_release_bulk(&priv->clk_bulk);
+
        return ret;
 }
 
@@ -458,6 +478,12 @@ static int usbhs_udc_otg_remove(struct udevice *dev)
 
        generic_shutdown_phy(&priv->phy);
 
+       reset_assert_bulk(&priv->reset_bulk);
+       reset_release_bulk(&priv->reset_bulk);
+
+       clk_disable_bulk(&priv->clk_bulk);
+       clk_release_bulk(&priv->clk_bulk);
+
        return dm_scan_fdt_dev(dev);
 }