clk: qcom: branch: Add mem ops support for branch2 clocks

Add the support for mem ops implementation to handle the sequence of
enable/disable of the memories in ethernet PHY, prior to enable/disable
of the respective clocks, which helps retain the respecive block's
register contents.
Signed-off-by: Taniya Das <quic_tdas@quicinc.com>
Signed-off-by: Imran Shaik <quic_imrashai@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20231123064735.2979802-3-quic_imrashai@quicinc.comSigned-off-by: Bjorn Andersson <andersson@kernel.org>

drivers/clk/qcom/clk-branch.c

 // 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_mem_branch *mem_br = to_clk_mem_branch(hw);
+	struct clk_branch branch = mem_br->branch;
+	u32 val;
+	int ret;
+
+	regmap_update_bits(branch.clkr.regmap, mem_br->mem_enable_reg,
+			   mem_br->mem_enable_ack_mask, mem_br->mem_enable_ack_mask);
+
+	ret = regmap_read_poll_timeout(branch.clkr.regmap, mem_br->mem_ack_reg,
+				       val, val & mem_br->mem_enable_ack_mask, 0, 200);
+	if (ret) {
+		WARN(1, "%s mem enable failed\n", clk_hw_get_name(&branch.clkr.hw));
+		return ret;
+	}
+
+	return clk_branch2_enable(hw);
+}
+
+static void clk_branch2_mem_disable(struct clk_hw *hw)
+{
+	struct clk_mem_branch *mem_br = to_clk_mem_branch(hw);
+
+	regmap_update_bits(mem_br->branch.clkr.regmap, mem_br->mem_enable_reg,
+			   mem_br->mem_enable_ack_mask, 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_GPL(clk_branch2_mem_ops);
+
 const struct clk_ops clk_branch2_ops = {
 	.enable = clk_branch2_enable,
 	.disable = clk_branch2_disable,

drivers/clk/qcom/clk-branch.h

@@ -38,6 +38,23 @@ struct clk_branch {
 	struct clk_regmap clkr;
 };
 
+/**
+ * struct clk_mem_branch - gating clock which are associated with memories
+ *
+ * @mem_enable_reg: branch clock memory gating register
+ * @mem_ack_reg: branch clock memory ack register
+ * @mem_enable_ack_mask: branch clock memory enable and ack field in @mem_ack_reg
+ * @branch: branch clock gating handle
+ *
+ * Clock which can gate its memories.
+ */
+struct clk_mem_branch {
+	u32	mem_enable_reg;
+	u32	mem_ack_reg;
+	u32	mem_enable_ack_mask;
+	struct clk_branch branch;
+};
+
 /* Branch clock common bits for HLOS-owned clocks */
 #define CBCR_CLK_OFF			BIT(31)
 #define CBCR_NOC_FSM_STATUS		GENMASK(30, 28)
@@ -85,8 +102,12 @@ 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)
 
+#define to_clk_mem_branch(_hw) \
+	container_of(to_clk_branch(_hw), struct clk_mem_branch, branch)
+
 #endif