From patchwork Fri Jul 10 12:55:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Ang, Chee Hong" X-Patchwork-Id: 241312 List-Id: U-Boot discussion From: chee.hong.ang at intel.com (Chee Hong Ang) Date: Fri, 10 Jul 2020 20:55:22 +0800 Subject: [PATCH v1 3/4] clk: agilex: Handle clock configuration differently in SPL and U-Boot proper In-Reply-To: <20200710125523.68008-1-chee.hong.ang@intel.com> References: <20200710125523.68008-1-chee.hong.ang@intel.com> Message-ID: <20200710125523.68008-4-chee.hong.ang@intel.com> Since warm reset may optionally set the CLock Manager to'boot mode', the clock driver should always force the Agilex's Clock Manager to 'boot mode' before the clock driver start configuring the Clock Manager in SPL. In SSBL, clock driver will skip the Clock Manager configuration if it's already being setup by SPL (Clock Manager NOT in 'boot mode') to prevent any inaccurate clocking issues happened on HPS peripherals such as UART, MAC and etc. Signed-off-by: Chee Hong Ang --- drivers/clk/altera/clk-agilex.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/clk/altera/clk-agilex.c b/drivers/clk/altera/clk-agilex.c index b5cf187364..c83eb2efb9 100644 --- a/drivers/clk/altera/clk-agilex.c +++ b/drivers/clk/altera/clk-agilex.c @@ -171,6 +171,16 @@ static void clk_basic_init(struct udevice *dev, if (!cfg) return; +#ifdef CONFIG_SPL_BUILD + /* Always force clock manager into boot mode before any configuration */ + clk_write_ctrl(plat, + CM_REG_READL(plat, CLKMGR_CTRL) | CLKMGR_CTRL_BOOTMODE); +#else + /* Skip clock configuration in SSBL if it's not in boot mode */ + if (!(CM_REG_READL(plat, CLKMGR_CTRL) & CLKMGR_CTRL_BOOTMODE)) + return; +#endif + /* Put both PLLs in bypass */ clk_write_bypass_mainpll(plat, CLKMGR_BYPASS_MAINPLL_ALL); clk_write_bypass_perpll(plat, CLKMGR_BYPASS_PERPLL_ALL);