User can get correct HCLK frequency during driver probe stage
by adding the following configuration in the device tree.
"clocks = <&scu ASPEED_CLK_AHB>".
Signed-off-by: Chin-Ting Kuo <chin-ting_...@aspeedtech.com>
Reviewed-by: Cédric Le Goater <c...@kaod.org>
---
drivers/clk/aspeed/clk_ast2500.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/clk/aspeed/clk_ast2500.c b/drivers/clk/aspeed/clk_ast2500.c
index 623c6915b8..dc446ce9fb 100644
--- a/drivers/clk/aspeed/clk_ast2500.c
+++ b/drivers/clk/aspeed/clk_ast2500.c
@@ -30,6 +30,12 @@
#define D2PLL_DEFAULT_RATE (250 * 1000 * 1000)
+/*
+ * AXI/AHB clock selection, taken from Aspeed SDK
+ */
+#define SCU_HWSTRAP_AXIAHB_DIV_SHIFT 9
+#define SCU_HWSTRAP_AXIAHB_DIV_MASK (0x7 << SCU_HWSTRAP_AXIAHB_DIV_SHIFT)
+
DECLARE_GLOBAL_DATA_PTR;
/*
@@ -86,6 +92,20 @@ static ulong ast2500_get_clkin(struct ast2500_scu *scu)
? 25 * 1000 * 1000 : 24 * 1000 * 1000;
}
+static u32 ast2500_get_hclk(ulong clkin, struct ast2500_scu *scu)
+{
+ u32 hpll_reg = readl(&scu->h_pll_param);
+ ulong axi_div = 2;
+ u32 rate;
+ ulong ahb_div = 1 + ((readl(&scu->hwstrap)
+ & SCU_HWSTRAP_AXIAHB_DIV_MASK)
+ >> SCU_HWSTRAP_AXIAHB_DIV_SHIFT);
+
+ rate = ast2500_get_hpll_rate(clkin, hpll_reg);
+
+ return (rate / axi_div / ahb_div);
+}
+
/**
* Get current rate or uart clock
*
@@ -147,6 +167,9 @@ static ulong ast2500_clk_get_rate(struct clk *clk)
rate = rate / apb_div;
}
break;
+ case ASPEED_CLK_AHB:
+ rate = ast2500_get_hclk(clkin, priv->scu);
+ break;
case ASPEED_CLK_SDIO:
{
ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
--
2.25.1
