Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:5 as permitted sender) client-ip=2620:137:e000::3:5;
From:   Alper Nebi Yasak <alpernebiyasak@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        Conor Dooley <conor+dt@kernel.org>, devicetree@vger.kernel.org,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        linux-mediatek@lists.infradead.org,
        =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Chen-Yu Tsai <wenst@chromium.org>, linux-clk@vger.kernel.org,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        Alper Nebi Yasak <alpernebiyasak@gmail.com>
Subject: [PATCH v2 1/2] clk: mediatek: mt8173-infracfg: Handle unallocated infracfg when module
Date:   Wed, 15 Nov 2023 20:06:24 +0300
Message-ID: <20231115170825.908640-1-alpernebiyasak@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The MT8173 infracfg clock driver does initialization in two steps, via a
CLK_OF_DECLARE_DRIVER declaration. However its early init function
doesn't get to run when it's built as a module, presumably since it's
not loaded by the time it would have been called by of_clk_init(). This
causes its second-step probe() to return -ENOMEM when trying to register
clocks, as the necessary clock_data struct isn't initialized by the
first step.

MT2701 and MT6797 clock drivers also use this mechanism, but they try to
allocate the necessary clock_data structure if missing in the second
step. Mimic that for the MT8173 infracfg clock as well to make it work
as a module.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
---

Changes in v2:
- Rewrite patch subject for consistency

v1: https://lore.kernel.org/lkml/20231108213734.140707-1-alpernebiyasak@gmail.com/

 drivers/clk/mediatek/clk-mt8173-infracfg.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/mediatek/clk-mt8173-infracfg.c b/drivers/clk/mediatek/clk-mt8173-infracfg.c
index 2f2f074e231a..ecc8b0063ea5 100644
--- a/drivers/clk/mediatek/clk-mt8173-infracfg.c
+++ b/drivers/clk/mediatek/clk-mt8173-infracfg.c
@@ -98,7 +98,17 @@ CLK_OF_DECLARE_DRIVER(mtk_infrasys, "mediatek,mt8173-infracfg",
 static int clk_mt8173_infracfg_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
-	int r;
+	int r, i;
+
+	if (!infra_clk_data) {
+		infra_clk_data = mtk_alloc_clk_data(CLK_INFRA_NR_CLK);
+		if (!infra_clk_data)
+			return -ENOMEM;
+	} else {
+		for (i = 0; i < CLK_INFRA_NR_CLK; i++)
+			if (infra_clk_data->hws[i] == ERR_PTR(-EPROBE_DEFER))
+				infra_clk_data->hws[i] = ERR_PTR(-ENOENT);
+	}
 
 	r = mtk_clk_register_gates(&pdev->dev, node, infra_gates,
 				   ARRAY_SIZE(infra_gates), infra_clk_data);

base-commit: bc962b35b139dd52319e6fc0f4bab00593bf38c9
-- 
2.42.0