From patchwork Thu Jul 30 18:26:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Saenz Julienne X-Patchwork-Id: 11693523 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C7FFD722 for ; Thu, 30 Jul 2020 18:28:34 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A18F420829 for ; Thu, 30 Jul 2020 18:28:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kQtiqdM6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A18F420829 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=z8vDAKL3xJLdDaZgM+ScOI5Gf2tyUzJefL8rySJqx9Q=; b=kQtiqdM6kUbJmQMrSR+YUutUSw oSVjvgPEeIhfyGZXD0qj0RMJPJil3fyKjJSMzxh9Gs94j5kxoMgs2p43IsUYCt7HqhhEK307M4Fo2 aOtoWcRxoKtsT1SXVfJBz+Ivmj947ZYYcifbt4t2Y7Rjhok2+GtpeENHw5swBjOYwqbheVRccpj3T Yfez51p5VA/xiAqOcpTGf2ylMrSJElp64K87E/z1cp1sirPRHwVOPFU+7w0iPC4VkGNar5Y6XYEmh pnjcMvMaRmv1F1BVE2dDakflgz5fft2hNrq2cY1nz8rkcoU3HgmgDBv+p6d+L9ZsG515S7U9QlAPC 2Uf6Qi1A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1DGH-0000hP-W1; Thu, 30 Jul 2020 18:26:38 +0000 Received: from mx2.suse.de ([195.135.220.15]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1DGE-0000gx-Rn; Thu, 30 Jul 2020 18:26:35 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DF4CDABCE; Thu, 30 Jul 2020 18:26:44 +0000 (UTC) From: Nicolas Saenz Julienne To: Nicolas Saenz Julienne , Florian Fainelli , Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Eric Anholt , Stefan Wahren , Matthias Brugger Subject: [PATCH v2] clk: bcm2835: Do not use prediv with bcm2711's PLLs Date: Thu, 30 Jul 2020 20:26:19 +0200 Message-Id: <20200730182619.23246-1-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200730_142635_137717_4BDBC8C1 X-CRM114-Status: GOOD ( 20.45 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [195.135.220.15 listed in list.dnswl.org] 0.0 RCVD_IN_MSPIKE_H3 RBL: Good reputation (+3) [195.135.220.15 listed in wl.mailspike.net] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record 0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Stephen Boyd , kernel-list@raspberrypi.com, Michael Turquette , linux-kernel@vger.kernel.org, pbrobinson@gmail.com, Nathan Chancellor , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rpi-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Contrary to previous SoCs, bcm2711 doesn't have a prescaler in the PLL feedback loop. Bypass it by zeroing fb_prediv_mask when running on bcm2711. Note that, since the prediv configuration bits were re-purposed, this was triggering miscalculations on all clocks hanging from the VPU clock, notably the aux UART, making its output unintelligible. Fixes: 42de9ad400af ("clk: bcm2835: Add BCM2711_CLOCK_EMMC2 support") Reported-by: Nathan Chancellor Signed-off-by: Nicolas Saenz Julienne Tested-by: Nathan Chancellor Reviewed-by: Florian Fainelli --- Changes since v1: - Previous approach broken. Check if running on bcm2711 upon using fb_prediv_mask. FYI relevant discussion with RPi engineers: https://github.com/raspberrypi/firmware/issues/1435#issuecomment-666242077 drivers/clk/bcm/clk-bcm2835.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 027eba31f793..3439bc65bb4e 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -314,6 +314,7 @@ struct bcm2835_cprman { struct device *dev; void __iomem *regs; spinlock_t regs_lock; /* spinlock for all clocks */ + unsigned int soc; /* * Real names of cprman clock parents looked up through @@ -526,6 +527,20 @@ static int bcm2835_pll_is_on(struct clk_hw *hw) A2W_PLL_CTRL_PRST_DISABLE; } +static u32 bcm2835_pll_get_prediv_mask(struct bcm2835_cprman *cprman, + const struct bcm2835_pll_data *data) +{ + /* + * On BCM2711 there isn't a pre-divisor available in the PLL feedback + * loop. Bits 13:14 of ANA1 (PLLA,PLLB,PLLC,PLLD) have been re-purposed + * for to for VCO RANGE bits. + */ + if (cprman->soc & SOC_BCM2711) + return 0; + + return data->ana->fb_prediv_mask; +} + static void bcm2835_pll_choose_ndiv_and_fdiv(unsigned long rate, unsigned long parent_rate, u32 *ndiv, u32 *fdiv) @@ -583,7 +598,7 @@ static unsigned long bcm2835_pll_get_rate(struct clk_hw *hw, ndiv = (a2wctrl & A2W_PLL_CTRL_NDIV_MASK) >> A2W_PLL_CTRL_NDIV_SHIFT; pdiv = (a2wctrl & A2W_PLL_CTRL_PDIV_MASK) >> A2W_PLL_CTRL_PDIV_SHIFT; using_prediv = cprman_read(cprman, data->ana_reg_base + 4) & - data->ana->fb_prediv_mask; + bcm2835_pll_get_prediv_mask(cprman, data); if (using_prediv) { ndiv *= 2; @@ -666,6 +681,7 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw, struct bcm2835_pll *pll = container_of(hw, struct bcm2835_pll, hw); struct bcm2835_cprman *cprman = pll->cprman; const struct bcm2835_pll_data *data = pll->data; + u32 prediv_mask = bcm2835_pll_get_prediv_mask(cprman, data); bool was_using_prediv, use_fb_prediv, do_ana_setup_first; u32 ndiv, fdiv, a2w_ctl; u32 ana[4]; @@ -683,7 +699,7 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw, for (i = 3; i >= 0; i--) ana[i] = cprman_read(cprman, data->ana_reg_base + i * 4); - was_using_prediv = ana[1] & data->ana->fb_prediv_mask; + was_using_prediv = ana[1] & prediv_mask; ana[0] &= ~data->ana->mask0; ana[0] |= data->ana->set0; @@ -693,10 +709,10 @@ static int bcm2835_pll_set_rate(struct clk_hw *hw, ana[3] |= data->ana->set3; if (was_using_prediv && !use_fb_prediv) { - ana[1] &= ~data->ana->fb_prediv_mask; + ana[1] &= ~prediv_mask; do_ana_setup_first = true; } else if (!was_using_prediv && use_fb_prediv) { - ana[1] |= data->ana->fb_prediv_mask; + ana[1] |= prediv_mask; do_ana_setup_first = false; } else { do_ana_setup_first = true; @@ -2262,6 +2278,7 @@ static int bcm2835_clk_probe(struct platform_device *pdev) platform_set_drvdata(pdev, cprman); cprman->onecell.num = asize; + cprman->soc = pdata->soc; hws = cprman->onecell.hws; for (i = 0; i < asize; i++) {