From patchwork Fri Mar 8 00:57:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Judith Mendez X-Patchwork-Id: 779067 Received: from fllv0015.ext.ti.com (fllv0015.ext.ti.com [198.47.19.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1247B25626; Fri, 8 Mar 2024 00:57:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.47.19.141 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709859480; cv=none; b=kmuC24sd3vo+nb9qzB7gkzkSztDjOuiFVmHG5W9+VuBHNdBqOADYvg8pS/QHumBXfusiclX9W6KKnasPyLFTw9OMHLTfjNIdct6DQ58QPXWhPcvC21UjKSp6cq/J5aCuRW6I36jChBzBMxb9nlbvrrKMvzY6eORXaMPs6cQwiAo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709859480; c=relaxed/simple; bh=bKR8gr0VhgU9ziFEGGnF6q1dlSQS1xPWrIYsKkxj8zY=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uEZtauFwsRnlXcFJU3AMVWYa0ny2ykZ6KZ1qzYqpyrRcRfmGx7k+PoAqyXdLszMQp0KQACj877Z7I7clDNTDuOspOcqaIfZimUY72fY/Qtpkul/zRYimTBr7En+lkUxrkk6zy6jUFctr+IVUwfVNJPNRAKKUkciMUPn+0MqDymw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com; spf=pass smtp.mailfrom=ti.com; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b=aug+cr0L; arc=none smtp.client-ip=198.47.19.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ti.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="aug+cr0L" Received: from fllv0035.itg.ti.com ([10.64.41.0]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 4280vkPx069442; Thu, 7 Mar 2024 18:57:46 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1709859466; bh=WTfn342mC3gAfKxYRNJ+eItseUz/rdHDe4G0Gh0iqsk=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=aug+cr0LAueGnJOwAC6OSRAceYJDZW+nEUIyEsuFF5aKXqqIJq0ry6qY4HVkZe3+P M2KvqjyEKPq/fclezeM9Ycz9QW3Z2c/XhdCUS5mq5qcFPCoHbR/tMvv+yDkpVooVpS H0U3b+9sx3P+ttJZ2lRG+X1t1TfGNB5am5qqMo+A= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 4280vkjv031449 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 7 Mar 2024 18:57:46 -0600 Received: from DLEE103.ent.ti.com (157.170.170.33) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 7 Mar 2024 18:57:46 -0600 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DLEE103.ent.ti.com (157.170.170.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 7 Mar 2024 18:57:46 -0600 Received: from judy-hp.dhcp.ti.com (judy-hp.dhcp.ti.com [128.247.81.105]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 4280vkjS055151; Thu, 7 Mar 2024 18:57:46 -0600 From: Judith Mendez To: Ulf Hansson , Adrian Hunter CC: Andrew Davis , , Subject: [PATCH v3 1/7] mmc: sdhci_am654: Add tuning algorithm for delay chain Date: Thu, 7 Mar 2024 18:57:40 -0600 Message-ID: <20240308005746.1059813-2-jm@ti.com> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240308005746.1059813-1-jm@ti.com> References: <20240308005746.1059813-1-jm@ti.com> Precedence: bulk X-Mailing-List: linux-mmc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Currently the sdhci_am654 driver only supports one tuning algorithm which should be used only when DLL is enabled. The ITAPDLY is selected from the largest passing window and the buffer is viewed as a circular buffer. The new algorithm should be used when the delay chain is enabled. The ITAPDLY is selected from the largest passing window and the buffer is not viewed as a circular buffer. This implementation is based off of the following paper: [1]. Also add support for multiple failing windows. [1] https://www.ti.com/lit/an/spract9/spract9.pdf Fixes: 13ebeae68ac9 ("mmc: sdhci_am654: Add support for software tuning") Signed-off-by: Judith Mendez Acked-by: Adrian Hunter --- Changelog: v2->v3: - Fix return for tuning algorithm - Fix ITAPDLY_LAST_INDEX - Use reverse fir tree order for variable declarations - Remove unnecessary parenthesis --- drivers/mmc/host/sdhci_am654.c | 112 +++++++++++++++++++++++++++------ 1 file changed, 92 insertions(+), 20 deletions(-) diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c index d659c59422e1..d11b0d769e6c 100644 --- a/drivers/mmc/host/sdhci_am654.c +++ b/drivers/mmc/host/sdhci_am654.c @@ -149,10 +149,17 @@ struct sdhci_am654_data { int strb_sel; u32 flags; u32 quirks; + bool dll_enable; #define SDHCI_AM654_QUIRK_FORCE_CDTEST BIT(0) }; +struct window { + u8 start; + u8 end; + u8 length; +}; + struct sdhci_am654_driver_data { const struct sdhci_pltfm_data *pdata; u32 flags; @@ -290,10 +297,12 @@ static void sdhci_am654_set_clock(struct sdhci_host *host, unsigned int clock) regmap_update_bits(sdhci_am654->base, PHY_CTRL4, mask, val); - if (timing > MMC_TIMING_UHS_SDR25 && clock >= CLOCK_TOO_SLOW_HZ) + if (timing > MMC_TIMING_UHS_SDR25 && clock >= CLOCK_TOO_SLOW_HZ) { sdhci_am654_setup_dll(host, clock); - else + sdhci_am654->dll_enable = true; + } else { sdhci_am654_setup_delay_chain(sdhci_am654, timing); + } regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK, sdhci_am654->clkbuf_sel); @@ -408,39 +417,102 @@ static u32 sdhci_am654_cqhci_irq(struct sdhci_host *host, u32 intmask) return 0; } -#define ITAP_MAX 32 +#define ITAPDLY_LENGTH 32 +#define ITAPDLY_LAST_INDEX (ITAPDLY_LENGTH - 1) + +static u32 sdhci_am654_calculate_itap(struct sdhci_host *host, struct window + *fail_window, u8 num_fails, bool circular_buffer) +{ + u8 itap = 0, start_fail = 0, end_fail = 0, pass_length = 0; + u8 first_fail_start = 0, last_fail_end = 0; + struct device *dev = mmc_dev(host->mmc); + struct window pass_window = {0, 0, 0}; + int prev_fail_end = -1; + + u8 i; + + if (!num_fails) + return ITAPDLY_LAST_INDEX >> 1; + + if (fail_window->length == ITAPDLY_LENGTH) { + dev_err(dev, "No passing ITAPDLY, return 0\n"); + return 0; + } + + first_fail_start = fail_window->start; + last_fail_end = fail_window[num_fails - 1].end; + + for (i = 0; i < num_fails; i++) { + start_fail = fail_window[i].start; + end_fail = fail_window[i].end; + pass_length = start_fail - (prev_fail_end + 1); + + if (pass_length > pass_window.length) { + pass_window.start = prev_fail_end + 1; + pass_window.length = pass_length; + } + prev_fail_end = end_fail; + } + + if (!circular_buffer) + pass_length = ITAPDLY_LAST_INDEX - last_fail_end; + else + pass_length = ITAPDLY_LAST_INDEX - last_fail_end + first_fail_start; + + if (pass_length > pass_window.length) { + pass_window.start = last_fail_end + 1; + pass_window.length = pass_length; + } + + if (!circular_buffer) + itap = pass_window.start + (pass_window.length >> 1); + else + itap = (pass_window.start + (pass_window.length >> 1)) % ITAPDLY_LENGTH; + + return (itap > ITAPDLY_LAST_INDEX) ? ITAPDLY_LAST_INDEX >> 1 : itap; +} + static int sdhci_am654_platform_execute_tuning(struct sdhci_host *host, u32 opcode) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_am654_data *sdhci_am654 = sdhci_pltfm_priv(pltfm_host); - int cur_val, prev_val = 1, fail_len = 0, pass_window = 0, pass_len; - u32 itap; + struct window fail_window[ITAPDLY_LENGTH]; + u8 curr_pass, itap; + u8 fail_index = 0; + u8 prev_pass = 1; + + memset(fail_window, 0, sizeof(fail_window)); /* Enable ITAPDLY */ regmap_update_bits(sdhci_am654->base, PHY_CTRL4, ITAPDLYENA_MASK, 1 << ITAPDLYENA_SHIFT); - for (itap = 0; itap < ITAP_MAX; itap++) { + for (itap = 0; itap < ITAPDLY_LENGTH; itap++) { sdhci_am654_write_itapdly(sdhci_am654, itap); - cur_val = !mmc_send_tuning(host->mmc, opcode, NULL); - if (cur_val && !prev_val) - pass_window = itap; + curr_pass = !mmc_send_tuning(host->mmc, opcode, NULL); - if (!cur_val) - fail_len++; + if (!curr_pass && prev_pass) + fail_window[fail_index].start = itap; - prev_val = cur_val; + if (!curr_pass) { + fail_window[fail_index].end = itap; + fail_window[fail_index].length++; + } + + if (curr_pass && !prev_pass) + fail_index++; + + prev_pass = curr_pass; } - /* - * Having determined the length of the failing window and start of - * the passing window calculate the length of the passing window and - * set the final value halfway through it considering the range as a - * circular buffer - */ - pass_len = ITAP_MAX - fail_len; - itap = (pass_window + (pass_len >> 1)) % ITAP_MAX; + + if (fail_window[fail_index].length != 0) + fail_index++; + + itap = sdhci_am654_calculate_itap(host, fail_window, fail_index, + sdhci_am654->dll_enable); + sdhci_am654_write_itapdly(sdhci_am654, itap); return 0;