From patchwork Mon Jul 30 17:20:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jacopo Mondi X-Patchwork-Id: 10549491 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 19E5214BC for ; Mon, 30 Jul 2018 17:20:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0ACFB2A448 for ; Mon, 30 Jul 2018 17:20:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F2D212A424; Mon, 30 Jul 2018 17:20:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 616802A465 for ; Mon, 30 Jul 2018 17:20:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727366AbeG3S43 (ORCPT ); Mon, 30 Jul 2018 14:56:29 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:32793 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726752AbeG3S43 (ORCPT ); Mon, 30 Jul 2018 14:56:29 -0400 X-Originating-IP: 2.224.242.101 Received: from w540.lan (2-224-242-101.ip172.fastwebnet.it [2.224.242.101]) (Authenticated sender: jacopo@jmondi.org) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id C727EE0004; Mon, 30 Jul 2018 17:20:27 +0000 (UTC) From: Jacopo Mondi To: Laurent Pinchart , David Airlie Cc: Jacopo Mondi , dri-devel@lists.freedesktop.org (open list:DRM DRIVERS FOR RENESAS), linux-renesas-soc@vger.kernel.org (open list:DRM DRIVERS FOR RENESAS), linux-kernel@vger.kernel.org (open list), Laurent Pinchart Subject: [PATCH 1/3] drm: rcar-du: Rework clock configuration based on hardware limits Date: Mon, 30 Jul 2018 19:20:12 +0200 Message-Id: <1532971214-17962-2-git-send-email-jacopo@jmondi.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1532971214-17962-1-git-send-email-jacopo@jmondi.org> References: <1532971214-17962-1-git-send-email-jacopo@jmondi.org> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Laurent Pinchart The DU channels that have a display PLL (DPLL) can only use external clock sources, and don't have an internal clock divider (with the exception of H3 ES1.x where the post-divider is present and needs to be used as a workaround for a DPLL silicon issue). Rework the clock configuration to take this into account, avoiding selection of non-existing clock sources or usage of a missing post-divider. Signed-off-by: Laurent Pinchart Reviewed-by: Jacopo Mondi --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 122 ++++++++++++++++++--------------- 1 file changed, 67 insertions(+), 55 deletions(-) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index b52b3e8..6d55cec 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -208,78 +208,90 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) const struct drm_display_mode *mode = &rcrtc->crtc.state->adjusted_mode; struct rcar_du_device *rcdu = rcrtc->group->dev; unsigned long mode_clock = mode->clock * 1000; - unsigned long clk; u32 value; u32 escr; - u32 div; - /* - * Compute the clock divisor and select the internal or external dot - * clock based on the requested frequency. - */ - clk = clk_get_rate(rcrtc->clock); - div = DIV_ROUND_CLOSEST(clk, mode_clock); - div = clamp(div, 1U, 64U) - 1; - escr = div | ESCR_DCLKSEL_CLKS; - - if (rcrtc->extclock) { + if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { + unsigned long target = mode_clock; struct dpll_info dpll = { 0 }; unsigned long extclk; - unsigned long extrate; - unsigned long rate; - u32 extdiv; + u32 dpllcr; + u32 div = 0; - extclk = clk_get_rate(rcrtc->extclock); - if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { - unsigned long target = mode_clock; + /* + * DU channels that have a display PLL can't use the internal + * system clock, and have no internal clock divider. + */ - /* - * The H3 ES1.x exhibits dot clock duty cycle stability - * issues. We can work around them by configuring the - * DPLL to twice the desired frequency, coupled with a - * /2 post-divider. This isn't needed on other SoCs and - * breaks HDMI output on M3-W for a currently unknown - * reason, so restrict the workaround to H3 ES1.x. - */ - if (soc_device_match(rcar_du_r8a7795_es1)) - target *= 2; + if (WARN_ON(!rcrtc->extclock)) + return; - rcar_du_dpll_divider(rcrtc, &dpll, extclk, target); - extclk = dpll.output; + /* + * The H3 ES1.x exhibits dot clock duty cycle stability issues. + * We can work around them by configuring the DPLL to twice the + * desired frequency, coupled with a /2 post-divider. Restrict + * the workaround to H3 ES1.x as ES2.0 and all other SoCs have + * no post-divider when a display PLL is present (as shown by + * the workaround breaking HDMI output on M3-W during testing). + */ + if (soc_device_match(rcar_du_r8a7795_es1)) { + target *= 2; + div = 1; } - extdiv = DIV_ROUND_CLOSEST(extclk, mode_clock); - extdiv = clamp(extdiv, 1U, 64U) - 1; + extclk = clk_get_rate(rcrtc->extclock); + rcar_du_dpll_divider(rcrtc, &dpll, extclk, target); - rate = clk / (div + 1); - extrate = extclk / (extdiv + 1); + dpllcr = DPLLCR_CODE | DPLLCR_CLKE + | DPLLCR_FDPLL(dpll.fdpll) + | DPLLCR_N(dpll.n) | DPLLCR_M(dpll.m) + | DPLLCR_STBY; - if (abs((long)extrate - (long)mode_clock) < - abs((long)rate - (long)mode_clock)) { + if (rcrtc->index == 1) + dpllcr |= DPLLCR_PLCS1 + | DPLLCR_INCS_DOTCLKIN1; + else + dpllcr |= DPLLCR_PLCS0 + | DPLLCR_INCS_DOTCLKIN0; - if (rcdu->info->dpll_ch & (1 << rcrtc->index)) { - u32 dpllcr = DPLLCR_CODE | DPLLCR_CLKE - | DPLLCR_FDPLL(dpll.fdpll) - | DPLLCR_N(dpll.n) | DPLLCR_M(dpll.m) - | DPLLCR_STBY; + rcar_du_group_write(rcrtc->group, DPLLCR, dpllcr); - if (rcrtc->index == 1) - dpllcr |= DPLLCR_PLCS1 - | DPLLCR_INCS_DOTCLKIN1; - else - dpllcr |= DPLLCR_PLCS0 - | DPLLCR_INCS_DOTCLKIN0; + escr = ESCR_DCLKSEL_DCLKIN | div; + } else { + unsigned long clk; + u32 div; - rcar_du_group_write(rcrtc->group, DPLLCR, - dpllcr); - } + /* + * Compute the clock divisor and select the internal or external + * dot clock based on the requested frequency. + */ + clk = clk_get_rate(rcrtc->clock); + div = DIV_ROUND_CLOSEST(clk, mode_clock); + div = clamp(div, 1U, 64U) - 1; - escr = ESCR_DCLKSEL_DCLKIN | extdiv; - } + escr = ESCR_DCLKSEL_CLKS | div; - dev_dbg(rcrtc->group->dev->dev, - "mode clock %lu extrate %lu rate %lu ESCR 0x%08x\n", - mode_clock, extrate, rate, escr); + if (rcrtc->extclock) { + unsigned long extclk; + unsigned long extrate; + unsigned long rate; + u32 extdiv; + + extclk = clk_get_rate(rcrtc->extclock); + extdiv = DIV_ROUND_CLOSEST(extclk, mode_clock); + extdiv = clamp(extdiv, 1U, 64U) - 1; + + extrate = extclk / (extdiv + 1); + rate = clk / (div + 1); + + if (abs((long)extrate - (long)mode_clock) < + abs((long)rate - (long)mode_clock)) + escr = ESCR_DCLKSEL_DCLKIN | extdiv; + + dev_dbg(rcrtc->group->dev->dev, + "mode clock %lu extrate %lu rate %lu ESCR 0x%08x\n", + mode_clock, extrate, rate, escr); + } } rcar_du_group_write(rcrtc->group, rcrtc->index % 2 ? ESCR2 : ESCR,