From patchwork Mon Dec 7 14:25:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jeffery X-Patchwork-Id: 339384 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 A0577C2BB48 for ; Mon, 7 Dec 2020 14:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89C18235DD for ; Mon, 7 Dec 2020 14:27:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726884AbgLGO1X (ORCPT ); Mon, 7 Dec 2020 09:27:23 -0500 Received: from out5-smtp.messagingengine.com ([66.111.4.29]:45751 "EHLO out5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725931AbgLGO1X (ORCPT ); Mon, 7 Dec 2020 09:27:23 -0500 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.nyi.internal (Postfix) with ESMTP id 3CA375C012F; Mon, 7 Dec 2020 09:26:16 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute3.internal (MEProxy); Mon, 07 Dec 2020 09:26:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aj.id.au; h=from :to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=fm1; bh=LBXQ1AXGfTSFg jE0H/tOMPvUmGXy9/AxdexCKUUzZ4E=; b=gs6aZXoPWgD+f4S4t2CWvVb6s3gqn 57FR1zE+OVxXHHTUtdzohm2loSK0Fw66uLBTQA4R6qCIVH/+EDJvqEuXfj/Gctpw uE9Km94g1kSIhy0DCItflMZ/Gcb1ldABtRxweQkETymPS1O/9jyGvwJMJbQ+KRk9 Kyy07ySjeUoUuzPLZrjWNQew5+vr2tMb+z4ytC9G+bW9G6xs4/2AHk04ckedMYVo 1uXVXTNy28ALc5bad6GKy3CJqUcODjGQrt9Jc8f3X7fgVGKVa4FczAKLqnT9M8VK 7xDMdfsEzWUATI0dkDxcTy1ZmOBFj4rQ1sVTBKDGXQh+3EY5e4u7FkRCQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:date:from :in-reply-to:message-id:mime-version:references:subject:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=LBXQ1AXGfTSFgjE0H/tOMPvUmGXy9/AxdexCKUUzZ4E=; b=bU9dFl4j sm9IGr6h3nLlZilp/wfPe8DFy5K9QXOWmgUJX1iGr+JG6Jtn/3DrZPIabVzMmsDN OBsVNWg+jsDdwGqoOd0lJ0efSk1QaXUf39CiSq5VDKeJGojq1gElbtmoyz4zdMhX nH/V7FSJYoraqLL/wbrO8idy9ier4IDSNwL6S1xG3/9i4Pj2566Zxqr0PGP8nAjU ZkD2dfdP0I6KxWkxaJgsBUA7yToSeyLthdR/NqsKI5SgWSVXYM01tN1rFihHdkw6 qPZIWACqnZETPR6SGuCS3NX5/dg3Tu47zSqFMdITuWPoLwgaAqWqBXWLlVCsICGI o1EcsC9hkRjxeQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedrudejgedgieegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefhvffufffkofgjfhgggfestdekre dtredttdenucfhrhhomheptehnughrvgifucflvghffhgvrhihuceorghnughrvgifsegr jhdrihgurdgruheqnecuggftrfgrthhtvghrnhepjefgvdevheetkeevgeegleelgfelte etjeffleffvdduudevieffgeetleevhfetnecukfhppedvtdefrdehjedrvddtkedrudeg ieenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpegrnh gurhgvfiesrghjrdhiugdrrghu X-ME-Proxy: Received: from localhost.localdomain (203-57-208-146.dyn.iinet.net.au [203.57.208.146]) by mail.messagingengine.com (Postfix) with ESMTPA id A59ED1080063; Mon, 7 Dec 2020 09:26:12 -0500 (EST) From: Andrew Jeffery To: linux-mmc@vger.kernel.org Cc: ulf.hansson@linaro.org, robh+dt@kernel.org, joel@jms.id.au, adrian.hunter@intel.com, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, ryan_chen@aspeedtech.com Subject: [PATCH v4 2/6] mmc: sdhci-of-aspeed: Expose clock phase controls Date: Tue, 8 Dec 2020 00:55:52 +1030 Message-Id: <20201207142556.2045481-3-andrew@aj.id.au> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201207142556.2045481-1-andrew@aj.id.au> References: <20201207142556.2045481-1-andrew@aj.id.au> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org The Aspeed SD/eMMC controllers expose configurable clock phase correction by inserting delays of up to 15 logic elements in length into the bus clock path. The hardware supports independent configuration for both bus directions on a per-slot basis. The timing delay per element encoded in the driver was experimentally determined by scope measurements. The phase controls for both slots are grouped together in a single register of the global register block of the SD/MMC controller(s), which drives the use of a locking scheme between the SDHCIs and the global register set. Signed-off-by: Andrew Jeffery --- drivers/mmc/host/sdhci-of-aspeed.c | 216 +++++++++++++++++++++++++++-- 1 file changed, 208 insertions(+), 8 deletions(-) diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c index 4f008ba3280e..788ec7728227 100644 --- a/drivers/mmc/host/sdhci-of-aspeed.c +++ b/drivers/mmc/host/sdhci-of-aspeed.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -16,9 +17,19 @@ #include "sdhci-pltfm.h" -#define ASPEED_SDC_INFO 0x00 -#define ASPEED_SDC_S1MMC8 BIT(25) -#define ASPEED_SDC_S0MMC8 BIT(24) +#define ASPEED_SDC_INFO 0x00 +#define ASPEED_SDC_S1_MMC8 BIT(25) +#define ASPEED_SDC_S0_MMC8 BIT(24) +#define ASPEED_SDC_PHASE 0xf4 +#define ASPEED_SDC_S1_PHASE_IN GENMASK(25, 21) +#define ASPEED_SDC_S0_PHASE_IN GENMASK(20, 16) +#define ASPEED_SDC_S1_PHASE_OUT GENMASK(15, 11) +#define ASPEED_SDC_S1_PHASE_IN_EN BIT(10) +#define ASPEED_SDC_S1_PHASE_OUT_EN GENMASK(9, 8) +#define ASPEED_SDC_S0_PHASE_OUT GENMASK(7, 3) +#define ASPEED_SDC_S0_PHASE_IN_EN BIT(2) +#define ASPEED_SDC_S0_PHASE_OUT_EN GENMASK(1, 0) +#define ASPEED_SDC_PHASE_MAX 31 struct aspeed_sdc { struct clk *clk; @@ -28,9 +39,36 @@ struct aspeed_sdc { void __iomem *regs; }; +struct aspeed_sdhci_tap_param { + bool valid; + +#define ASPEED_SDHCI_TAP_PARAM_INVERT_CLK BIT(4) + u8 in; + u8 out; +}; + +struct aspeed_sdhci_tap_desc { + u32 tap_mask; + u32 enable_mask; + u8 enable_value; +}; + +struct aspeed_sdhci_phase_desc { + struct aspeed_sdhci_tap_desc in; + struct aspeed_sdhci_tap_desc out; +}; + +struct aspeed_sdhci_pdata { + const struct aspeed_sdhci_phase_desc *phase_desc; + size_t nr_phase_descs; +}; + struct aspeed_sdhci { + const struct aspeed_sdhci_pdata *pdata; struct aspeed_sdc *parent; u32 width_mask; + mmc_clk_phase_map_t phase_map; + const struct aspeed_sdhci_phase_desc *phase_desc; }; static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc, @@ -50,10 +88,118 @@ static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc, spin_unlock(&sdc->lock); } +static u32 +aspeed_sdc_set_phase_tap(const struct aspeed_sdhci_tap_desc *desc, + u8 tap, bool enable, u32 reg) +{ + reg &= ~(desc->enable_mask | desc->tap_mask); + if (enable) { + reg |= tap << __ffs(desc->tap_mask); + reg |= desc->enable_value << __ffs(desc->enable_mask); + } + + return reg; +} + +static void +aspeed_sdc_set_phase_taps(struct aspeed_sdc *sdc, + const struct aspeed_sdhci_phase_desc *desc, + const struct aspeed_sdhci_tap_param *taps) +{ + u32 reg; + + spin_lock(&sdc->lock); + reg = readl(sdc->regs + ASPEED_SDC_PHASE); + + reg = aspeed_sdc_set_phase_tap(&desc->in, taps->in, taps->valid, reg); + reg = aspeed_sdc_set_phase_tap(&desc->out, taps->out, taps->valid, reg); + + writel(reg, sdc->regs + ASPEED_SDC_PHASE); + spin_unlock(&sdc->lock); +} + +#define PICOSECONDS_PER_SECOND 1000000000000ULL +#define ASPEED_SDHCI_NR_TAPS 15 +/* Measured value with *handwave* environmentals and static loading */ +#define ASPEED_SDHCI_MAX_TAP_DELAY_PS 1253 +static int aspeed_sdhci_phase_to_tap(struct device *dev, unsigned long rate_hz, + int phase_deg) +{ + u64 phase_period_ps; + u64 prop_delay_ps; + u64 clk_period_ps; + unsigned int tap; + u8 inverted; + + phase_deg %= 360; + + if (phase_deg >= 180) { + inverted = ASPEED_SDHCI_TAP_PARAM_INVERT_CLK; + phase_deg -= 180; + dev_dbg(dev, + "Inverting clock to reduce phase correction from %d to %d degrees\n", + phase_deg + 180, phase_deg); + } else { + inverted = 0; + } + + prop_delay_ps = ASPEED_SDHCI_MAX_TAP_DELAY_PS / ASPEED_SDHCI_NR_TAPS; + clk_period_ps = div_u64(PICOSECONDS_PER_SECOND, (u64)rate_hz); + phase_period_ps = div_u64((u64)phase_deg * clk_period_ps, 360ULL); + + tap = div_u64(phase_period_ps, prop_delay_ps); + if (tap > ASPEED_SDHCI_NR_TAPS) { + dev_warn(dev, + "Requested out of range phase tap %d for %d degrees of phase compensation at %luHz, clamping to tap %d\n", + tap, phase_deg, rate_hz, ASPEED_SDHCI_NR_TAPS); + tap = ASPEED_SDHCI_NR_TAPS; + } + + return inverted | tap; +} + +static void +aspeed_sdhci_phases_to_taps(struct device *dev, unsigned long rate, + const struct mmc_clk_phase *phases, + struct aspeed_sdhci_tap_param *taps) +{ + taps->valid = phases->valid; + + if (!phases->valid) + return; + + taps->in = aspeed_sdhci_phase_to_tap(dev, rate, phases->in_deg); + taps->out = aspeed_sdhci_phase_to_tap(dev, rate, phases->out_deg); +} + +static void +aspeed_sdhci_configure_phase(struct sdhci_host *host, unsigned long rate) +{ + struct aspeed_sdhci_tap_param _taps = {0}, *taps = &_taps; + struct mmc_clk_phase *params; + struct aspeed_sdhci *sdhci; + struct device *dev; + + dev = host->mmc->parent; + sdhci = sdhci_pltfm_priv(sdhci_priv(host)); + + if (!sdhci->phase_desc) + return; + + params = &sdhci->phase_map[host->timing]; + aspeed_sdhci_phases_to_taps(dev, rate, params, taps); + aspeed_sdc_set_phase_taps(sdhci->parent, sdhci->phase_desc, taps); + dev_dbg(dev, + "Using taps [%d, %d] for [%d, %d] degrees of phase correction at %luHz (%d)\n", + taps->in & ASPEED_SDHCI_NR_TAPS, + taps->out & ASPEED_SDHCI_NR_TAPS, + params->in_deg, params->out_deg, rate, host->timing); +} + static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host; - unsigned long parent; + unsigned long parent, bus; int div; u16 clk; @@ -69,13 +215,17 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock) clock = host->max_clk; for (div = 2; div < 256; div *= 2) { - if ((parent / div) <= clock) + bus = parent / div; + if (bus <= clock) break; } + div >>= 1; clk = div << SDHCI_DIVIDER_SHIFT; + aspeed_sdhci_configure_phase(host, bus); + sdhci_enable_clk(host, clk); } @@ -157,6 +307,7 @@ static inline int aspeed_sdhci_calculate_slot(struct aspeed_sdhci *dev, static int aspeed_sdhci_probe(struct platform_device *pdev) { + const struct aspeed_sdhci_pdata *aspeed_pdata; struct sdhci_pltfm_host *pltfm_host; struct aspeed_sdhci *dev; struct sdhci_host *host; @@ -164,12 +315,15 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) int slot; int ret; + aspeed_pdata = of_device_get_match_data(&pdev->dev); + host = sdhci_pltfm_init(pdev, &aspeed_sdhci_pdata, sizeof(*dev)); if (IS_ERR(host)) return PTR_ERR(host); pltfm_host = sdhci_priv(host); dev = sdhci_pltfm_priv(pltfm_host); + dev->pdata = aspeed_pdata; dev->parent = dev_get_drvdata(pdev->dev.parent); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -180,8 +334,17 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) else if (slot >= 2) return -EINVAL; - dev_info(&pdev->dev, "Configuring for slot %d\n", slot); - dev->width_mask = !slot ? ASPEED_SDC_S0MMC8 : ASPEED_SDC_S1MMC8; + if (dev->pdata && slot < dev->pdata->nr_phase_descs) { + dev->phase_desc = &dev->pdata->phase_desc[slot]; + } else { + dev_info(&pdev->dev, + "Phase control not supported for slot %d\n", slot); + dev->phase_desc = NULL; + } + + dev->width_mask = !slot ? ASPEED_SDC_S0_MMC8 : ASPEED_SDC_S1_MMC8; + + dev_info(&pdev->dev, "Configured for slot %d\n", slot); sdhci_get_of_property(pdev); @@ -199,6 +362,9 @@ static int aspeed_sdhci_probe(struct platform_device *pdev) if (ret) goto err_sdhci_add; + if (dev->phase_desc) + mmc_of_parse_clk_phase(host->mmc, dev->phase_map); + ret = sdhci_add_host(host); if (ret) goto err_sdhci_add; @@ -230,10 +396,44 @@ static int aspeed_sdhci_remove(struct platform_device *pdev) return 0; } +static const struct aspeed_sdhci_phase_desc ast2600_sdhci_phase[] = { + /* SDHCI/Slot 0 */ + [0] = { + .in = { + .tap_mask = ASPEED_SDC_S0_PHASE_IN, + .enable_mask = ASPEED_SDC_S0_PHASE_IN_EN, + .enable_value = 1, + }, + .out = { + .tap_mask = ASPEED_SDC_S0_PHASE_OUT, + .enable_mask = ASPEED_SDC_S0_PHASE_OUT_EN, + .enable_value = 3, + }, + }, + /* SDHCI/Slot 1 */ + [1] = { + .in = { + .tap_mask = ASPEED_SDC_S1_PHASE_IN, + .enable_mask = ASPEED_SDC_S1_PHASE_IN_EN, + .enable_value = 1, + }, + .out = { + .tap_mask = ASPEED_SDC_S1_PHASE_OUT, + .enable_mask = ASPEED_SDC_S1_PHASE_OUT_EN, + .enable_value = 3, + }, + }, +}; + +static const struct aspeed_sdhci_pdata ast2600_sdhci_pdata = { + .phase_desc = ast2600_sdhci_phase, + .nr_phase_descs = ARRAY_SIZE(ast2600_sdhci_phase), +}; + static const struct of_device_id aspeed_sdhci_of_match[] = { { .compatible = "aspeed,ast2400-sdhci", }, { .compatible = "aspeed,ast2500-sdhci", }, - { .compatible = "aspeed,ast2600-sdhci", }, + { .compatible = "aspeed,ast2600-sdhci", .data = &ast2600_sdhci_pdata, }, { } };