[U-Boot] [PATCH v3 6/7] usb: host: ohci-generic: add RESET support

[patrice.chotard at st.com]

From: Patrice Chotard <patrice.chotard at st.com>

use list to save reference to deasserted resets in order to
assert them in case of error during probe() or during driver
removal.

Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
---

v3:	_ extract in this patch the RESET support add-on from previous patch 5
	_ keep deassrted resets reference in list in order to 
	  assert resets in error path or in .remove callback

v2:	_ add error path management
	_ add .remove callback

 drivers/usb/host/ohci-generic.c | 78 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/drivers/usb/host/ohci-generic.c b/drivers/usb/host/ohci-generic.c
index a6d89a8..bf14ab7 100644
--- a/drivers/usb/host/ohci-generic.c
+++ b/drivers/usb/host/ohci-generic.c
@@ -7,6 +7,7 @@
 #include <common.h>
 #include <clk.h>
 #include <dm.h>
+#include <reset.h>
 #include "ohci.h"
 
 #if !defined(CONFIG_USB_OHCI_NEW)
@@ -18,11 +19,43 @@ struct ohci_clock {
 	struct list_head list;
 };
 
+struct ohci_reset {
+	struct reset_ctl *reset;
+	struct list_head list;
+};
+
 struct generic_ohci {
 	ohci_t ohci;
 	struct list_head clks;
+	struct list_head resets;
 };
 
+static int ohci_release_resets(struct generic_ohci *priv)
+{
+	struct ohci_reset *ohci_reset, *tmp;
+	struct reset_ctl *reset;
+	int ret;
+
+	list_for_each_entry_safe(ohci_reset, tmp, &priv->resets, list) {
+		reset = ohci_reset->reset;
+
+		ret = reset_request(reset);
+		if (ret)
+			return ret;
+
+		ret = reset_assert(reset);
+		if (ret)
+			return ret;
+
+		ret = reset_free(reset);
+		if (ret)
+			return ret;
+
+		list_del(&(ohci_reset->list));
+	}
+	return 0;
+}
+
 static int ohci_release_clocks(struct generic_ohci *priv)
 {
 	struct ohci_clock *ohci_clock, *tmp;
@@ -54,6 +87,7 @@ static int ohci_usb_probe(struct udevice *dev)
 	int i, ret;
 
 	INIT_LIST_HEAD(&priv->clks);
+	INIT_LIST_HEAD(&priv->resets);
 
 	for (i = 0; ; i++) {
 		struct ohci_clock *ohci_clock;
@@ -89,8 +123,48 @@ static int ohci_usb_probe(struct udevice *dev)
 		list_add(&ohci_clock->list, &priv->clks);
 	}
 
+	for (i = 0; ; i++) {
+		struct ohci_reset *ohci_reset;
+		struct reset_ctl *reset;
+
+		reset = devm_kmalloc(dev, sizeof(*reset), GFP_KERNEL);
+		if (!reset) {
+			error("Can't allocate resource\n");
+			goto clk_err;
+		}
+
+		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);
+			goto reset_err;
+		}
+		reset_free(reset);
+
+		/*
+		 * add deasserted resets into resets list in order to be
+		 * asserted later on ohci_usb_remove() call or in error
+		 * path if needed
+		 */
+		ohci_reset = devm_kmalloc(dev, sizeof(*ohci_reset), GFP_KERNEL);
+		if (!ohci_reset) {
+			error("Can't allocate resource\n");
+			goto reset_err;
+		}
+		ohci_reset->reset = reset;
+		list_add(&ohci_reset->list, &priv->resets);
+	}
+
+
 	return ohci_register(dev, regs);
 
+reset_err:
+	ret = ohci_release_resets(priv);
+	if (ret)
+		return ret;
 clk_err:
 	return ohci_release_clocks(priv);
 }
@@ -104,6 +178,10 @@ static int ohci_usb_remove(struct udevice *dev)
 	if (ret)
 		return ret;
 
+	ret = ohci_release_resets(priv);
+	if (ret)
+		return ret;
+
 	return ohci_release_clocks(priv);
 }
 
-- 
1.9.1