From 8e88bc5ff96131cec9a8154e862247dac5194460 Mon Sep 17 00:00:00 2001
From: Deepak Katragadda <dkatraga@codeaurora.org>
Date: Thu, 29 Sep 2016 13:28:59 +0530
Subject: [PATCH] clk: qcom: Add support for hardware control branch clocks

Add new ops to allow clock clients to enable/disable hardware
dynamic gating of the clock branch.

Change-Id: I14abed3827de8cefc31f3deb3c1e589136c32b8d
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>
Signed-off-by: David Dai <daidavid1@codeaurora.org>
Signed-off-by: David Collins <collinsd@codeaurora.org>
---
 drivers/clk/qcom/clk-branch.c | 56 +++++++++++++++++++++++++++++++++--
 drivers/clk/qcom/clk-branch.h |  5 ++--
 2 files changed, 57 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/qcom/clk-branch.c b/drivers/clk/qcom/clk-branch.c
index f869fc6aaed6..43ad05b584d7 100644
--- a/drivers/clk/qcom/clk-branch.c
+++ b/drivers/clk/qcom/clk-branch.c
@@ -1,6 +1,6 @@
-// SPDX-License-Identifier: GPL-2.0
+// SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013, 2016, The Linux Foundation. All rights reserved.
  */
 
 #include <linux/kernel.h>
@@ -8,6 +8,7 @@
 #include <linux/err.h>
 #include <linux/delay.h>
 #include <linux/export.h>
+#include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/regmap.h>
 
@@ -152,6 +153,57 @@ const struct clk_ops clk_branch2_aon_ops = {
 };
 EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
 
+static unsigned long clk_branch2_hw_ctl_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	return parent_rate;
+}
+
+static int clk_branch2_hw_ctl_determine_rate(struct clk_hw *hw,
+		struct clk_rate_request *req)
+{
+	struct clk_hw *clkp;
+
+	clkp = clk_hw_get_parent(hw);
+	if (!clkp)
+		return -EINVAL;
+
+	req->best_parent_hw = clkp;
+	req->best_parent_rate = clk_round_rate(clkp->clk, req->rate);
+
+	return 0;
+}
+
+static int clk_branch2_hw_ctl_enable(struct clk_hw *hw)
+{
+	struct clk_hw *parent = clk_hw_get_parent(hw);
+
+	/* The parent branch clock should have been prepared prior to this. */
+	if (!parent || (parent && !clk_hw_is_prepared(parent)))
+		return -EINVAL;
+
+	return clk_enable_regmap(hw);
+}
+
+static void clk_branch2_hw_ctl_disable(struct clk_hw *hw)
+{
+	struct clk_hw *parent = clk_hw_get_parent(hw);
+
+	if (!parent)
+		return;
+
+	clk_disable_regmap(hw);
+}
+
+const struct clk_ops clk_branch2_hw_ctl_ops = {
+	.enable = clk_branch2_hw_ctl_enable,
+	.disable = clk_branch2_hw_ctl_disable,
+	.is_enabled = clk_is_enabled_regmap,
+	.recalc_rate = clk_branch2_hw_ctl_recalc_rate,
+	.determine_rate = clk_branch2_hw_ctl_determine_rate,
+};
+EXPORT_SYMBOL(clk_branch2_hw_ctl_ops);
+
 const struct clk_ops clk_branch_simple_ops = {
 	.enable = clk_enable_regmap,
 	.disable = clk_disable_regmap,
diff --git a/drivers/clk/qcom/clk-branch.h b/drivers/clk/qcom/clk-branch.h
index 17a58119165e..8f71551b2aea 100644
--- a/drivers/clk/qcom/clk-branch.h
+++ b/drivers/clk/qcom/clk-branch.h
@@ -1,5 +1,5 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* Copyright (c) 2013, The Linux Foundation. All rights reserved. */
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2013, 2016, The Linux Foundation. All rights reserved. */
 
 #ifndef __QCOM_CLK_BRANCH_H__
 #define __QCOM_CLK_BRANCH_H__
@@ -39,6 +39,7 @@ struct clk_branch {
 
 extern const struct clk_ops clk_branch_ops;
 extern const struct clk_ops clk_branch2_ops;
+extern const struct clk_ops clk_branch2_hw_ctl_ops;
 extern const struct clk_ops clk_branch_simple_ops;
 extern const struct clk_ops clk_branch2_aon_ops;