[PATCH v3 10/10] clk: mediatek: clk-mt8192: Add clock mux notifier for mfg_pll_sel

From: AngeloGioacchino Del Regno
Date: Tue Sep 27 2022 - 06:12:22 EST


Following the changes that were done for mt8183, add a clock notifier
for the GPU PLL selector mux: this allows safe clock rate changes by
temporarily reparenting the GPU to a safe clock (clk26m) while the
MFGPLL is reprogrammed and stabilizes.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Reviewed-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
---
drivers/clk/mediatek/clk-mt8192.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)

diff --git a/drivers/clk/mediatek/clk-mt8192.c b/drivers/clk/mediatek/clk-mt8192.c
index ebbd2798d9a3..187dbffeb987 100644
--- a/drivers/clk/mediatek/clk-mt8192.c
+++ b/drivers/clk/mediatek/clk-mt8192.c
@@ -1224,6 +1224,28 @@ static void clk_mt8192_top_init_early(struct device_node *node)
CLK_OF_DECLARE_DRIVER(mt8192_topckgen, "mediatek,mt8192-topckgen",
clk_mt8192_top_init_early);

+/* Register mux notifier for MFG mux */
+static int clk_mt8192_reg_mfg_mux_notifier(struct device *dev, struct clk *clk)
+{
+ struct mtk_mux_nb *mfg_mux_nb;
+ int i;
+
+ mfg_mux_nb = devm_kzalloc(dev, sizeof(*mfg_mux_nb), GFP_KERNEL);
+ if (!mfg_mux_nb)
+ return -ENOMEM;
+
+ for (i = 0; i < ARRAY_SIZE(top_mtk_muxes); i++)
+ if (top_mtk_muxes[i].id == CLK_TOP_MFG_PLL_SEL)
+ break;
+ if (i == ARRAY_SIZE(top_mtk_muxes))
+ return -EINVAL;
+
+ mfg_mux_nb->ops = top_mtk_muxes[i].ops;
+ mfg_mux_nb->bypass_index = 0; /* Bypass to 26M crystal */
+
+ return devm_mtk_clk_mux_notifier_register(dev, clk, mfg_mux_nb);
+}
+
static int clk_mt8192_top_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
@@ -1247,6 +1269,12 @@ static int clk_mt8192_top_probe(struct platform_device *pdev)
if (r)
return r;

+ r = clk_mt8192_reg_mfg_mux_notifier(&pdev->dev,
+ top_clk_data->hws[CLK_TOP_MFG_PLL_SEL]->clk);
+ if (r)
+ return r;
+
+
return of_clk_add_hw_provider(node, of_clk_hw_onecell_get,
top_clk_data);
}
--
2.37.2