linux-kernel - [PATCH v3 2/5] clk: imx: fracn-gppll: correct PLL initialization flow

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20241027-imx-clk-v1-v3-2-89152574d1d7@nxp.com>
Date: Sun, 27 Oct 2024 20:00:08 +0800
From: "Peng Fan (OSS)" <peng.fan@....nxp.com>
To: Abel Vesa <abelvesa@...nel.org>, 
 Michael Turquette <mturquette@...libre.com>, 
 Stephen Boyd <sboyd@...nel.org>, Shawn Guo <shawnguo@...nel.org>, 
 Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, Aisheng Dong <aisheng.dong@....com>
Cc: linux-clk@...r.kernel.org, imx@...ts.linux.dev, 
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Abel Vesa <abel.vesa@...aro.org>, Peng Fan <peng.fan@....com>, 
 Jacky Bai <ping.bai@....com>
Subject: [PATCH v3 2/5] clk: imx: fracn-gppll: correct PLL initialization
 flow

From: Peng Fan <peng.fan@....com>

Per i.MX93 Reference Mannual 22.4 Initialization information
1. Program appropriate value of DIV[ODIV], DIV[RDIV] and DIV[MFI]
   as per Integer mode.
2. Wait for 5 μs.
3. Program the following field in CTRL register.
   Set CTRL[POWERUP] to 1'b1 to enable PLL block.
4. Poll PLL_STATUS[PLL_LOCK] register, and wait till PLL_STATUS[PLL_LOCK]
   is 1'b1 and pll_lock output signal is 1'b1.
5. Set CTRL[CLKMUX_EN] to 1'b1 to enable PLL output clock.

So move the CLKMUX_EN operation after PLL locked.

Fixes: 1b26cb8a77a4 ("clk: imx: support fracn gppll")
Co-developed-by: Jacky Bai <ping.bai@....com>
Signed-off-by: Jacky Bai <ping.bai@....com>
Signed-off-by: Peng Fan <peng.fan@....com>
---
 drivers/clk/imx/clk-fracn-gppll.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/imx/clk-fracn-gppll.c b/drivers/clk/imx/clk-fracn-gppll.c
index 591e0364ee5c113859a7b6271c8c11e98a0e0ffc..4749c3e0b7051cf53876664808aa28742f6861f7 100644
--- a/drivers/clk/imx/clk-fracn-gppll.c
+++ b/drivers/clk/imx/clk-fracn-gppll.c
@@ -303,13 +303,13 @@ static int clk_fracn_gppll_prepare(struct clk_hw *hw)
 	val |= POWERUP_MASK;
 	writel_relaxed(val, pll->base + PLL_CTRL);
 
-	val |= CLKMUX_EN;
-	writel_relaxed(val, pll->base + PLL_CTRL);
-
 	ret = clk_fracn_gppll_wait_lock(pll);
 	if (ret)
 		return ret;
 
+	val |= CLKMUX_EN;
+	writel_relaxed(val, pll->base + PLL_CTRL);
+
 	val &= ~CLKMUX_BYPASS;
 	writel_relaxed(val, pll->base + PLL_CTRL);
 

-- 
2.37.1