From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16CC7C433E0 for ; Tue, 4 Aug 2020 16:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 069A920738 for ; Tue, 4 Aug 2020 16:00:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729157AbgHDQAe (ORCPT ); Tue, 4 Aug 2020 12:00:34 -0400 Received: from relay3-d.mail.gandi.net ([217.70.183.195]:48521 "EHLO relay3-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbgHDQAb (ORCPT ); Tue, 4 Aug 2020 12:00:31 -0400 X-Originating-IP: 86.202.118.225 Received: from localhost (lfbn-lyo-1-23-225.w86-202.abo.wanadoo.fr [86.202.118.225]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 20F0E6000C; Tue, 4 Aug 2020 16:00:28 +0000 (UTC) Date: Tue, 4 Aug 2020 18:00:28 +0200 From: Alexandre Belloni To: Claudiu Beznea Cc: mturquette@baylibre.com, sboyd@kernel.org, nicolas.ferre@microchip.com, ludovic.desroches@microchip.com, mturquette@linaro.org, bbrezillon@kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] clk: at91: clk-main: update key before writing AT91_CKGR_MOR Message-ID: <20200804160028.GD10725@piout.net> References: <1596099803-1393-1-git-send-email-claudiu.beznea@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1596099803-1393-1-git-send-email-claudiu.beznea@microchip.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/07/2020 12:03:23+0300, Claudiu Beznea wrote: > SAMA5D2 datasheet specifies on chapter 33.22.8 (PMC Clock Generator > Main Oscillator Register) that writing any value other than > 0x37 on KEY field aborts the write operation. Use the key when > selecting main clock parent. > > Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation") > Signed-off-by: Claudiu Beznea Reviewed-by: Alexandre Belloni > --- > drivers/clk/at91/clk-main.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c > index 5c83e899084f..cfae2f59df66 100644 > --- a/drivers/clk/at91/clk-main.c > +++ b/drivers/clk/at91/clk-main.c > @@ -437,12 +437,17 @@ static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index) > return -EINVAL; > > regmap_read(regmap, AT91_CKGR_MOR, &tmp); > - tmp &= ~MOR_KEY_MASK; > > if (index && !(tmp & AT91_PMC_MOSCSEL)) > - regmap_write(regmap, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL); > + tmp = AT91_PMC_MOSCSEL; > else if (!index && (tmp & AT91_PMC_MOSCSEL)) > - regmap_write(regmap, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL); > + tmp = 0; > + else > + return 0; > + > + regmap_update_bits(regmap, AT91_CKGR_MOR, > + AT91_PMC_MOSCSEL | MOR_KEY_MASK, > + tmp | AT91_PMC_KEY); > > while (!clk_sam9x5_main_ready(regmap)) > cpu_relax(); > -- > 2.7.4 > -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com