[v2,10/10] clk: mediatek: clk-mt8192: Add clock mux notifier for mfg_pll_sel

Commit Message

AngeloGioacchino Del Regno Sept. 15, 2022, 7:24 a.m. UTC

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 <[e-mail]>
---
 drivers/clk/mediatek/clk-mt8192.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Comments

Chen-Yu Tsai Sept. 26, 2022, 3:23 a.m. UTC | #1

On Thu, Sep 15, 2022 at 3:25 PM AngeloGioacchino Del Regno
<[e-mail]> wrote:
>
> 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 <[e-mail]>

Reviewed-by: Chen-Yu Tsai <[e-mail]>

Patch

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);
 }