linux-kernel - [PATCH 5/8] clk: loongson2: Avoid hardcoding firmware name of the reference clock

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Message-ID: <20250523104552.32742-6-ziyao@disroot.org>
Date: Fri, 23 May 2025 10:45:49 +0000
From: Yao Zi <ziyao@...root.org>
To: Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Huacai Chen <chenhuacai@...nel.org>,
	WANG Xuerui <kernel@...0n.name>,
	Yinbo Zhu <zhuyinbo@...ngson.cn>
Cc: linux-clk@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	loongarch@...ts.linux.dev,
	Mingcong Bai <jeffbai@...c.io>,
	Kexy Biscuit <kexybiscuit@...c.io>,
	Yao Zi <ziyao@...root.org>
Subject: [PATCH 5/8] clk: loongson2: Avoid hardcoding firmware name of the reference clock

Loongson 2K0300 requires a reference clock with a frequency different
from previous SoCs (120MHz v.s. 100MHz), thus hardcoding the firmware
name of the reference clock as ref_100m isn't a good idea.

This patch retrives the clock name of the reference clock dynamically
during probe, avoiding the hardcoded pdata structure and preparing for
support of future SoCs.

Signed-off-by: Yao Zi <ziyao@...root.org>
---
 drivers/clk/clk-loongson2.c | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c
index 7a916c7d2718..52a9f1c2794a 100644
--- a/drivers/clk/clk-loongson2.c
+++ b/drivers/clk/clk-loongson2.c
@@ -13,10 +13,6 @@
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <dt-bindings/clock/loongson,ls2k-clk.h>
 
-static const struct clk_parent_data pdata[] = {
-	{ .fw_name = "ref_100m", },
-};
-
 enum loongson2_clk_type {
 	CLK_TYPE_PLL,
 	CLK_TYPE_SCALE,
@@ -275,7 +271,8 @@ static const struct clk_ops loongson2_freqscale_recalc_ops = {
 	.recalc_rate = loongson2_freqscale_recalc_rate,
 };
 
-static struct clk_hw *loongson2_clk_register(struct loongson2_clk_provider *clp,
+static struct clk_hw *loongson2_clk_register(const char *parent,
+					     struct loongson2_clk_provider *clp,
 					     const struct loongson2_clk_board_info *cld,
 					     const struct clk_ops *ops)
 {
@@ -292,11 +289,7 @@ static struct clk_hw *loongson2_clk_register(struct loongson2_clk_provider *clp,
 	init.ops   = ops;
 	init.flags = 0;
 	init.num_parents = 1;
-
-	if (!cld->parent_name)
-		init.parent_data = pdata;
-	else
-		init.parent_names = &cld->parent_name;
+	init.parent_names = &parent;
 
 	clk->reg	= clp->base + cld->reg_offset;
 	clk->div_shift	= cld->div_shift;
@@ -321,11 +314,17 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct loongson2_clk_provider *clp;
 	const struct loongson2_clk_board_info *p, *data;
+	const char *refclk_name, *parent_name;
 
 	data = device_get_match_data(dev);
 	if (!data)
 		return -EINVAL;
 
+	refclk_name = of_clk_get_parent_name(dev->of_node, 0);
+	if (IS_ERR(refclk_name))
+		return dev_err_probe(dev, PTR_ERR(refclk_name),
+				     "failed to get refclk name\n");
+
 	for (p = data; p->name; p++)
 		clks_num = max(clks_num, p->id + 1);
 
@@ -347,18 +346,20 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 
 	for (i = 0; i < clks_num; i++) {
 		p = &data[i];
+		parent_name = p->parent_name ? p->parent_name : refclk_name;
+
 		switch (p->type) {
 		case CLK_TYPE_PLL:
-			hw = loongson2_clk_register(clp, p,
+			hw = loongson2_clk_register(parent_name, clp, p,
 						    &loongson2_pll_recalc_ops);
 			break;
 		case CLK_TYPE_SCALE:
-			hw = loongson2_clk_register(clp, p,
+			hw = loongson2_clk_register(parent_name, clp, p,
 						    &loongson2_freqscale_recalc_ops);
 			break;
 		case CLK_TYPE_DIVIDER:
 			hw = devm_clk_hw_register_divider(dev, p->name,
-							  p->parent_name, 0,
+							  parent_name, 0,
 							  clp->base + p->reg_offset,
 							  p->div_shift, p->div_width,
 							  CLK_DIVIDER_ONE_BASED |
@@ -366,15 +367,15 @@ static int loongson2_clk_probe(struct platform_device *pdev)
 							  &clp->clk_lock);
 			break;
 		case CLK_TYPE_GATE:
-			hw = devm_clk_hw_register_gate(dev, p->name, p->parent_name,
+			hw = devm_clk_hw_register_gate(dev, p->name, parent_name,
 						       p->flags,
 						       clp->base + p->reg_offset,
 						       p->bit_idx, 0,
 						       &clp->clk_lock);
 			break;
 		case CLK_TYPE_FIXED:
-			hw = devm_clk_hw_register_fixed_rate_parent_data(dev, p->name, pdata,
-									 0, p->fixed_rate);
+			hw = devm_clk_hw_register_fixed_rate(dev, p->name, parent_name,
+							     0, p->fixed_rate);
 			break;
 		default:
 			return dev_err_probe(dev, -EINVAL, "Invalid clk type\n");
-- 
2.49.0