[U-Boot] [PATCH v3 5/7] usb: host: ohci-generic: add CLOCK support

[patrice.chotard at st.com]

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

use list to save reference to enabled clocks in order to
disabled 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 CLOCK support add-on from previous patch 5
	_ keep enabled clocks reference in list in order to 
	  disable clocks in error path or in .remove callback

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

 drivers/usb/host/ohci-generic.c | 81 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/ohci-generic.c b/drivers/usb/host/ohci-generic.c
index f3307f4..a6d89a8 100644
--- a/drivers/usb/host/ohci-generic.c
+++ b/drivers/usb/host/ohci-generic.c
@@ -5,6 +5,7 @@
  */
 
 #include <common.h>
+#include <clk.h>
 #include <dm.h>
 #include "ohci.h"
 
@@ -12,20 +13,98 @@
 # error "Generic OHCI driver requires CONFIG_USB_OHCI_NEW"
 #endif
 
+struct ohci_clock {
+	struct clk *clk;
+	struct list_head list;
+};
+
 struct generic_ohci {
 	ohci_t ohci;
+	struct list_head clks;
 };
 
+static int ohci_release_clocks(struct generic_ohci *priv)
+{
+	struct ohci_clock *ohci_clock, *tmp;
+	struct clk *clk;
+	int ret;
+
+	list_for_each_entry_safe(ohci_clock, tmp, &priv->clks, list) {
+		clk = ohci_clock->clk;
+
+		clk_request(clk->dev, clk);
+		if (ret)
+			return ret;
+
+		clk_disable(clk);
+
+		ret = clk_free(clk);
+		if (ret)
+			return ret;
+
+		list_del(&ohci_clock->list);
+	}
+	return 0;
+}
+
 static int ohci_usb_probe(struct udevice *dev)
 {
 	struct ohci_regs *regs = (struct ohci_regs *)dev_get_addr(dev);
+	struct generic_ohci *priv = dev_get_priv(dev);
+	int i, ret;
+
+	INIT_LIST_HEAD(&priv->clks);
+
+	for (i = 0; ; i++) {
+		struct ohci_clock *ohci_clock;
+		struct clk *clk;
+
+		clk = devm_kmalloc(dev, sizeof(*clk), GFP_KERNEL);
+		if (!clk) {
+			error("Can't allocate resource\n");
+			goto clk_err;
+		}
+
+		ret = clk_get_by_index(dev, i, clk);
+		if (ret < 0)
+			break;
+
+		if (clk_enable(clk)) {
+			error("failed to enable ohci_clock %d\n", i);
+			clk_free(clk);
+			goto clk_err;
+		}
+		clk_free(clk);
+
+		/*
+		 * add enabled clocks into clks list in order to be disabled
+		 * later on ohci_usb_remove() call or in error path if needed
+		 */
+		ohci_clock = devm_kmalloc(dev, sizeof(*ohci_clock), GFP_KERNEL);
+		if (!ohci_clock) {
+			error("Can't allocate resource\n");
+			goto clk_err;
+		}
+		ohci_clock->clk = clk;
+		list_add(&ohci_clock->list, &priv->clks);
+	}
 
 	return ohci_register(dev, regs);
+
+clk_err:
+	return ohci_release_clocks(priv);
 }
 
 static int ohci_usb_remove(struct udevice *dev)
 {
-	return ohci_deregister(dev);
+	struct generic_ohci *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = ohci_deregister(dev);
+	if (ret)
+		return ret;
+
+	return ohci_release_clocks(priv);
 }
 
 static const struct udevice_id ohci_usb_ids[] = {
-- 
1.9.1