From a7e82204743c3095deeac73e3142152d325141f8 Mon Sep 17 00:00:00 2001 From: Chin-Ting Kuo Date: Fri, 19 Aug 2022 17:01:02 +0800 Subject: [PATCH] clk: aspeed: Get HCLK frequency support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Cédric Le Goater --- 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 623c691..dc446ce 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) -- 2.7.4