[U-Boot] [PATCH V3 2/4] clk: prograte clk enable/disable to parent

[Peng Fan]

On i.MX8MM, thinking such as clk path
OSC->PLL->PLL GATE->CCM ROOT->CCGR GATE->Device

Only enabling CCGR GATE is not enough, we also need to enable PLL GATE
to make sure the clk path work. So when enabling CCGR GATE,
we could prograte to enabling PLL GATE to make life easier.

Signed-off-by: Peng Fan <peng.fan at nxp.com>
---

V3:
 None
V2:
 Improve commit log
 Check enable_count when enable/disable to avoid touch hardware
 following Linux

 drivers/clk/clk-uclass.c | 77 ++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 71 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
index c66b6f3c4e..64c181f4ad 100644
--- a/drivers/clk/clk-uclass.c
+++ b/drivers/clk/clk-uclass.c
@@ -449,13 +449,45 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
 int clk_enable(struct clk *clk)
 {
 	const struct clk_ops *ops = clk_dev_ops(clk->dev);
+	struct clk *clkp = NULL;
+	int ret;
 
 	debug("%s(clk=%p)\n", __func__, clk);
 
-	if (!ops->enable)
-		return -ENOSYS;
+	if (CONFIG_IS_ENABLED(CLK_CCF)) {
+		/* Take id 0 as a non-valid clk, such as dummy */
+		if (clk->id && !clk_get_by_id(clk->id, &clkp)) {
+			if (clkp->enable_count) {
+				clkp->enable_count++;
+				return 0;
+			}
+			if (clkp->dev->parent &&
+			    device_get_uclass_id(clkp->dev) == UCLASS_CLK) {
+				ret = clk_enable(dev_get_clk_ptr(clkp->dev->parent));
+				if (ret) {
+					printf("Enable %s failed\n",
+					       clkp->dev->parent->name);
+					return ret;
+				}
+			}
+		}
 
-	return ops->enable(clk);
+		if (ops->enable) {
+			ret = ops->enable(clk);
+			if (ret) {
+				printf("Enable %s failed\n", clk->dev->name);
+				return ret;
+			}
+		}
+		if (clkp)
+			clkp->enable_count++;
+	} else {
+		if (!ops->enable)
+			return -ENOSYS;
+		return ops->enable(clk);
+	}
+
+	return 0;
 }
 
 int clk_enable_bulk(struct clk_bulk *bulk)
@@ -474,13 +506,46 @@ int clk_enable_bulk(struct clk_bulk *bulk)
 int clk_disable(struct clk *clk)
 {
 	const struct clk_ops *ops = clk_dev_ops(clk->dev);
+	struct clk *clkp = NULL;
+	int ret;
 
 	debug("%s(clk=%p)\n", __func__, clk);
 
-	if (!ops->disable)
-		return -ENOSYS;
+	if (CONFIG_IS_ENABLED(CLK_CCF)) {
+		if (clk->id && !clk_get_by_id(clk->id, &clkp)) {
+			if (clkp->enable_count == 0) {
+				printf("clk %s already disabled\n",
+				       clkp->dev->name);
+				return 0;
+			}
 
-	return ops->disable(clk);
+			if (--clkp->enable_count > 0)
+				return 0;
+		}
+
+		if (ops->disable) {
+			ret = ops->disable(clk);
+			if (ret)
+				return ret;
+		}
+
+		if (clkp && clkp->dev->parent &&
+		    device_get_uclass_id(clkp->dev) == UCLASS_CLK) {
+			ret = clk_disable(dev_get_clk_ptr(clkp->dev->parent));
+			if (ret) {
+				printf("Disable %s failed\n",
+				       clkp->dev->parent->name);
+				return ret;
+			}
+		}
+	} else {
+		if (!ops->disable)
+			return -ENOSYS;
+
+		return ops->disable(clk);
+	}
+
+	return 0;
 }
 
 int clk_disable_bulk(struct clk_bulk *bulk)
-- 
2.16.4