[PATCH 2/4] clk: qcom: branch: Add mem ops support for branch2 clocks

[Imran Shaik <quic_imrashai@xxxxxxxxxxx>]

From: Taniya Das <quic_tdas@xxxxxxxxxxx>

Clock CBCRs with memories need an update for memory before enable/disable
of the clock. Add support for the mem ops to handle this sequence.

Signed-off-by: Taniya Das <quic_tdas@xxxxxxxxxxx>
Signed-off-by: Imran Shaik <quic_imrashai@xxxxxxxxxxx>
---
 drivers/clk/qcom/clk-branch.c | 38 +++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-branch.h |  4 ++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/clk/qcom/clk-branch.c b/drivers/clk/qcom/clk-branch.c
index fc4735f74f0f..95ffcd380039 100644
--- a/drivers/clk/qcom/clk-branch.c
+++ b/drivers/clk/qcom/clk-branch.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
  */
 
 #include <linux/kernel.h>
@@ -134,6 +135,43 @@ static void clk_branch2_disable(struct clk_hw *hw)
 	clk_branch_toggle(hw, false, clk_branch2_check_halt);
 }
 
+static int clk_branch2_mem_enable(struct clk_hw *hw)
+{
+	struct clk_branch *br = to_clk_branch(hw);
+	u32 val;
+	int count = 200;
+
+	regmap_update_bits(br->clkr.regmap, br->mem_enable_reg,
+			br->mem_enable_ack_bit, br->mem_enable_ack_bit);
+
+	regmap_read(br->clkr.regmap, br->mem_ack_reg, &val);
+
+	while (count-- > 0) {
+		if (val & br->mem_enable_ack_bit)
+			return clk_branch2_enable(hw);
+		udelay(1);
+		regmap_read(br->clkr.regmap, br->mem_ack_reg, &val);
+	}
+
+	return -EBUSY;
+}
+
+static void clk_branch2_mem_disable(struct clk_hw *hw)
+{
+	struct clk_branch *br = to_clk_branch(hw);
+
+	regmap_update_bits(br->clkr.regmap, br->mem_enable_reg,
+						br->mem_enable_ack_bit, 0);
+	return clk_branch2_disable(hw);
+}
+
+const struct clk_ops clk_branch2_mem_ops = {
+	.enable = clk_branch2_mem_enable,
+	.disable = clk_branch2_mem_disable,
+	.is_enabled = clk_is_enabled_regmap,
+};
+EXPORT_SYMBOL(clk_branch2_mem_ops);
+
 const struct clk_ops clk_branch2_ops = {
 	.enable = clk_branch2_enable,
 	.disable = clk_branch2_disable,
diff --git a/drivers/clk/qcom/clk-branch.h b/drivers/clk/qcom/clk-branch.h
index 0cf800b9d08d..0ffda6bef00e 100644
--- a/drivers/clk/qcom/clk-branch.h
+++ b/drivers/clk/qcom/clk-branch.h
@@ -24,8 +24,11 @@
 struct clk_branch {
 	u32	hwcg_reg;
 	u32	halt_reg;
+	u32	mem_enable_reg;
+	u32	mem_ack_reg;
 	u8	hwcg_bit;
 	u8	halt_bit;
+	u8	mem_enable_ack_bit;
 	u8	halt_check;
 #define BRANCH_VOTED			BIT(7) /* Delay on disable */
 #define BRANCH_HALT			0 /* pol: 1 = halt */
@@ -85,6 +88,7 @@ extern const struct clk_ops clk_branch_ops;
 extern const struct clk_ops clk_branch2_ops;
 extern const struct clk_ops clk_branch_simple_ops;
 extern const struct clk_ops clk_branch2_aon_ops;
+extern const struct clk_ops clk_branch2_mem_ops;
 
 #define to_clk_branch(_hw) \
 	container_of(to_clk_regmap(_hw), struct clk_branch, clkr)
-- 
2.25.1