From patchwork Mon Jun 20 17:56:44 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 9188399 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8F494607D1 for ; Mon, 20 Jun 2016 18:03:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8526C2780C for ; Mon, 20 Jun 2016 18:03:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 799A827C14; Mon, 20 Jun 2016 18:03:11 +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=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 278392780C for ; Mon, 20 Jun 2016 18:03:11 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bF3W7-0007iq-RN; Mon, 20 Jun 2016 18:01:47 +0000 Received: from mail-pf0-x233.google.com ([2607:f8b0:400e:c00::233]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bF3VN-0007Bt-3R for linux-arm-kernel@lists.infradead.org; Mon, 20 Jun 2016 18:01:02 +0000 Received: by mail-pf0-x233.google.com with SMTP id h14so41117758pfe.1 for ; Mon, 20 Jun 2016 11:00:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=L5YCNT6XiGvqXROuN10HB2Hoc04hegAmSQEf3szD5bA=; b=TWR+bqPEQE166QGbDFrZM9RJUtFZAh78unDZeKr1mG07TLNSFAACBkY6MjvMw8keQ+ z1VXJ2LJ7YqV9h0w4tNaeKciQ/sR4zw4uae6165+C2hMEUpB+Uv7HnjSheMECNyg+ZY2 FivZfEMJwomrOSTZvTWBZGpATZTBPn4sGyNmk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=L5YCNT6XiGvqXROuN10HB2Hoc04hegAmSQEf3szD5bA=; b=br/Jq60yfEsE4+J47KKDfKi3g7MxDe5NLM3o60eZPrO7x82pRJsHEQnt0nLRy5hkR5 4edBGIShG2v7KUOA1YD1alWnzMpE+R47PnFsOixGlgudGIvoTzNZFBCd0dREKjaodBIX EQsoaZgLN+A7USNpuIr6rB/aj5sKo5M8PtqKVbbI7no8DCefEV7AQJGuR0vXcMUegQJZ an1q+5xw3kdh/4TtdaWvz+tooRmgM41sakIblV27bkpbA7UbZpbPp+GPMLlQKPezUcCP 9nqE35J9tLcdceiEgPJt9DlGIMoSkj7+TK1CIPKCfmK/5Oqwokd6ro3hQtHP9rT3x8av 7GHg== X-Gm-Message-State: ALyK8tKpYym68EdWK3OlO43r9i5YF7o0JPzszcXybjOYqg47kX8h+jWP+sbraqLFp064qczr X-Received: by 10.98.70.144 with SMTP id o16mr22843889pfi.126.1466445638634; Mon, 20 Jun 2016 11:00:38 -0700 (PDT) Received: from tictac.mtv.corp.google.com ([172.22.65.76]) by smtp.gmail.com with ESMTPSA id c189sm60250353pfg.19.2016.06.20.11.00.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 20 Jun 2016 11:00:37 -0700 (PDT) From: Douglas Anderson To: ulf.hansson@linaro.org, Heiko Stuebner Subject: [PATCH v3 05/15] phy: rockchip-emmc: Increase lock time allowance Date: Mon, 20 Jun 2016 10:56:44 -0700 Message-Id: <1466445414-11974-6-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: <1466445414-11974-1-git-send-email-dianders@chromium.org> References: <1466445414-11974-1-git-send-email-dianders@chromium.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160620_110101_284102_CFA05BD6 X-CRM114-Status: GOOD ( 17.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Douglas Anderson , devicetree@vger.kernel.org, xzy.xu@rock-chips.com, linux-kernel@vger.kernel.org, shawn.lin@rock-chips.com, briannorris@chromium.org, linux-mmc@vger.kernel.org, adrian.hunter@intel.com, kishon@ti.com, linux-rockchip@lists.infradead.org, robh+dt@kernel.org, groeck@chromium.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Previous PHY code waited a fixed amount of time for the DLL to lock at power on time. Unfortunately, the time for the DLL to lock is actually a bit more dynamic and can be longer if the card clock is slower. Instead of waiting a fixed 30 us, let's now dynamically wait until the lock bit gets set. We'll wait up to 10 ms which should be OK even if the card clock is at the super slow 100 kHz. On its own, this change makes the PHY power on code a little more robust. Before this change the PHY was relying on the eMMC code to make sure the PHY was only powered on when the card clock was set to at least 50 MHz before, though this reliance wasn't documented anywhere. This change will be even more useful in future changes where we actually need to be able to wait for a DLL lock at slower clock speeds. Signed-off-by: Douglas Anderson Acked-by: Kishon Vijay Abraham I Reviewed-by: Shawn Lin Tested-by: Heiko Stuebner --- Changes in v3: - Add collected tags Changes in v2: - Indicate that 5.1 ms is calculated (Shawn). drivers/phy/phy-rockchip-emmc.c | 28 ++++++++++++++++++++-------- 1 file changed, 20 insertions(+), 8 deletions(-) diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c index a69f53630e67..2d059c046978 100644 --- a/drivers/phy/phy-rockchip-emmc.c +++ b/drivers/phy/phy-rockchip-emmc.c @@ -85,6 +85,7 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, { unsigned int caldone; unsigned int dllrdy; + unsigned long timeout; /* * Keep phyctrl_pdb and phyctrl_endll low to allow @@ -137,15 +138,26 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy, PHYCTRL_ENDLL_MASK, PHYCTRL_ENDLL_SHIFT)); /* - * After enable analog DLL circuits, we need an extra 10.2us - * for dll to be ready for work. But according to testing, we - * find some chips need more than 25us. + * After enabling analog DLL circuits docs say that we need 10.2 us if + * our source clock is at 50 MHz and that lock time scales linearly + * with clock speed. If we are powering on the PHY and the card clock + * is super slow (like 100 kHZ) this could take as long as 5.1 ms as + * per the math: 10.2 us * (50000000 Hz / 100000 Hz) => 5.1 ms + * Hopefully we won't be running at 100 kHz, but we should still make + * sure we wait long enough. */ - udelay(30); - regmap_read(rk_phy->reg_base, - rk_phy->reg_offset + GRF_EMMCPHY_STATUS, - &dllrdy); - dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK; + timeout = jiffies + msecs_to_jiffies(10); + do { + udelay(1); + + regmap_read(rk_phy->reg_base, + rk_phy->reg_offset + GRF_EMMCPHY_STATUS, + &dllrdy); + dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK; + if (dllrdy == PHYCTRL_DLLRDY_DONE) + break; + } while (!time_after(jiffies, timeout)); + if (dllrdy != PHYCTRL_DLLRDY_DONE) { pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n"); return -ETIMEDOUT;