linux-kernel - [PATCH 3/3] clk: gate: support regmap

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Date:   Fri, 28 May 2021 19:34:03 +0800
From:   "Peng Fan (OSS)" <peng.fan@....nxp.com>
To:     sboyd@...nel.org, mturquette@...libre.com
Cc:     linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, kernel@...gutronix.de,
        Peng Fan <peng.fan@....com>
Subject: [PATCH 3/3] clk: gate: support regmap

From: Peng Fan <peng.fan@....com>

To i.MX8ULP, a PCC register provides clk(mux, gate, divider) and peripheral
reset functionality, so we need make sure the access to the PCC register
be protected to avoid concurrent access from clk and reset subsystem.

So let's use regmap here.

Signed-off-by: Peng Fan <peng.fan@....com>
---
 drivers/clk/clk-gate.c       | 26 +++++++++++++++++++++++---
 include/linux/clk-provider.h |  3 +++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk-gate.c b/drivers/clk/clk-gate.c
index 070dc47e95a1..1acaa2f5a969 100644
--- a/drivers/clk/clk-gate.c
+++ b/drivers/clk/clk-gate.c
@@ -8,6 +8,7 @@
 
 #include <linux/clk-provider.h>
 #include <linux/module.h>
+#include <linux/regmap.h>
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/err.h>
@@ -25,18 +26,37 @@
 
 static inline u32 clk_gate_readl(struct clk_gate *gate)
 {
-	if (gate->flags & CLK_GATE_BIG_ENDIAN)
+	int ret;
+	u32 val;
+
+	if (gate->flags & CLK_GATE_BIG_ENDIAN) {
 		return ioread32be(gate->reg);
+	} else if (gate->flags & CLK_GATE_REGMAP) {
+		ret = regmap_read(gate->regmap, gate->reg_off, &val);
+		if (ret < 0) {
+			pr_warn("%s: failed %x, %d\n", __func__, gate->reg_off, ret);
+			return ret;
+		} else {
+			return val;
+		}
+	}
 
 	return readl(gate->reg);
 }
 
 static inline void clk_gate_writel(struct clk_gate *gate, u32 val)
 {
-	if (gate->flags & CLK_GATE_BIG_ENDIAN)
+	int ret;
+
+	if (gate->flags & CLK_GATE_BIG_ENDIAN) {
 		iowrite32be(val, gate->reg);
-	else
+	} else if (gate->flags & CLK_GATE_REGMAP) {
+		ret = regmap_write(gate->regmap, gate->reg_off, val);
+		if (ret < 0)
+			pr_warn("%s: %x: %d\n", __func__, gate->reg_off, ret);
+	} else {
 		writel(val, gate->reg);
+	}
 }
 
 /*
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 3902f883cdaf..0a4c01a023cc 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -474,6 +474,8 @@ struct clk_gate {
 	u8		bit_idx;
 	u8		flags;
 	spinlock_t	*lock;
+	struct regmap	*regmap;
+	u32		reg_off;
 };
 
 #define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw)
@@ -481,6 +483,7 @@ struct clk_gate {
 #define CLK_GATE_SET_TO_DISABLE		BIT(0)
 #define CLK_GATE_HIWORD_MASK		BIT(1)
 #define CLK_GATE_BIG_ENDIAN		BIT(2)
+#define CLK_GATE_REGMAP			BIT(3)
 
 extern const struct clk_ops clk_gate_ops;
 struct clk_hw *__clk_hw_register_gate(struct device *dev,
-- 
2.30.0