From a1cee8e808042e2597d162b1687fdb470634271e Mon Sep 17 00:00:00 2001
From: Patrice Chotard <patrice.chotard@st.com>
Date: Tue, 18 Jul 2017 11:57:10 +0200
Subject: [PATCH] usb: host: ehci-generic: add error path and .remove callback

Use an array to save enabled clocks reference and deasserted resets
in order to respectively disabled and asserted them in case of error
during probe() or during driver removal.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
 drivers/usb/host/ehci-generic.c | 118 ++++++++++++++++++++++++++++++++--------
 1 file changed, 95 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/host/ehci-generic.c b/drivers/usb/host/ehci-generic.c
index 2116ae1..e058445 100644
--- a/drivers/usb/host/ehci-generic.c
+++ b/drivers/usb/host/ehci-generic.c
@@ -6,6 +6,7 @@
 
 #include <common.h>
 #include <clk.h>
+#include <dm/ofnode.h>
 #include <reset.h>
 #include <asm/io.h>
 #include <dm.h>
@@ -18,43 +19,114 @@
  */
 struct generic_ehci {
 	struct ehci_ctrl ctrl;
+	struct clk *clocks;
+	struct reset_ctl *resets;
+	int clock_count;
+	int reset_count;
 };
 
 static int ehci_usb_probe(struct udevice *dev)
 {
+	struct generic_ehci *priv = dev_get_priv(dev);
 	struct ehci_hccr *hccr;
 	struct ehci_hcor *hcor;
-	int i;
-
-	for (i = 0; ; i++) {
-		struct clk clk;
-		int ret;
-
-		ret = clk_get_by_index(dev, i, &clk);
-		if (ret < 0)
-			break;
-		if (clk_enable(&clk))
-			error("failed to enable clock %d\n", i);
-		clk_free(&clk);
+	int i, err, ret, clock_nb, reset_nb;
+
+	err = 0;
+	priv->clock_count = 0;
+	clock_nb = ofnode_count_phandle_with_args(dev_ofnode(dev), "clocks",
+						  "#clock-cells");
+	if (clock_nb > 0) {
+		priv->clocks = devm_kcalloc(dev, clock_nb, sizeof(struct clk),
+					    GFP_KERNEL);
+		if (!priv->clocks)
+			return -ENOMEM;
+
+		for (i = 0; i < clock_nb; i++) {
+			err = clk_get_by_index(dev, i, &priv->clocks[i]);
+
+			if (err < 0)
+				break;
+			err = clk_enable(&priv->clocks[i]);
+			if (err) {
+				error("failed to enable clock %d\n", i);
+				clk_free(&priv->clocks[i]);
+				goto clk_err;
+			}
+			priv->clock_count++;
+		}
+	} else {
+		if (clock_nb != -ENOENT) {
+			error("failed to get clock phandle(%d)\n", clock_nb);
+			return clock_nb;
+		}
 	}
 
-	for (i = 0; ; i++) {
-		struct reset_ctl reset;
-		int ret;
+	priv->reset_count = 0;
+	reset_nb = ofnode_count_phandle_with_args(dev_ofnode(dev), "resets",
+						  "#reset-cells");
+	if (reset_nb > 0) {
+		priv->resets = devm_kcalloc(dev, reset_nb,
+					    sizeof(struct reset_ctl),
+					    GFP_KERNEL);
+		if (!priv->resets)
+			return -ENOMEM;
+
+		for (i = 0; i < reset_nb; i++) {
+			err = reset_get_by_index(dev, i, &priv->resets[i]);
+			if (err < 0)
+				break;
 
-		ret = reset_get_by_index(dev, i, &reset);
-		if (ret < 0)
-			break;
-		if (reset_deassert(&reset))
-			error("failed to deassert reset %d\n", i);
-		reset_free(&reset);
+			if (reset_deassert(&priv->resets[i])) {
+				error("failed to deassert reset %d\n", i);
+				reset_free(&priv->resets[i]);
+				goto reset_err;
+			}
+			priv->reset_count++;
+		}
+	} else {
+		if (reset_nb != -ENOENT) {
+			error("failed to get reset phandle(%d)\n", reset_nb);
+			goto clk_err;
+		}
 	}
 
 	hccr = map_physmem(devfdt_get_addr(dev), 0x100, MAP_NOCACHE);
 	hcor = (struct ehci_hcor *)((uintptr_t)hccr +
 				    HC_LENGTH(ehci_readl(&hccr->cr_capbase)));
 
-	return ehci_register(dev, hccr, hcor, NULL, 0, USB_INIT_HOST);
+	err = ehci_register(dev, hccr, hcor, NULL, 0, USB_INIT_HOST);
+	if (err)
+		goto reset_err;
+
+	return 0;
+
+reset_err:
+	ret = reset_release_all(priv->resets, priv->reset_count);
+	if (ret)
+		error("failed to assert all resets\n");
+clk_err:
+	ret = clk_release_all(priv->clocks, priv->clock_count);
+	if (ret)
+		error("failed to disable all clocks\n");
+
+	return err;
+}
+
+static int ehci_usb_remove(struct udevice *dev)
+{
+	struct generic_ehci *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = ehci_deregister(dev);
+	if (ret)
+		return ret;
+
+	ret =  reset_release_all(priv->resets, priv->reset_count);
+	if (ret)
+		return ret;
+
+	return clk_release_all(priv->clocks, priv->clock_count);
 }
 
 static const struct udevice_id ehci_usb_ids[] = {
@@ -67,7 +139,7 @@ U_BOOT_DRIVER(ehci_generic) = {
 	.id	= UCLASS_USB,
 	.of_match = ehci_usb_ids,
 	.probe = ehci_usb_probe,
-	.remove = ehci_deregister,
+	.remove = ehci_usb_remove,
 	.ops	= &ehci_usb_ops,
 	.priv_auto_alloc_size = sizeof(struct generic_ehci),
 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
-- 
2.7.4