From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 62AD8196D90; Thu, 6 Jun 2024 14:21:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683671; cv=none; b=tHRPsyTb6m09p3j3PKZ7oaXu0XjLzdNluKyprarCvnKehbXN5IJ9Gh93unuVn6cBwWrr1AHVl8kY8ocMitabRIPt9ajJLH0RhhEu1G9eHtER2pgxcyYqvA1I1gQ2Ql5/RY8SLevMt2uZKi6lH+Ex9Hitydw6qZJmmuaod9cblJY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683671; c=relaxed/simple; bh=+kOt4ntjqKiQv/f7txchd3u4wA0I2fyF+kfQj/aXP3M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ABCrevHeBMMQ9YQ4vsyDIFssrZ+30G/Ju8cpDnwTTDHEal4poaG7eZDBBUNOgnVvSugALtsi2P06Ep8HLjOsQRc0k25654rkE6p4VgMZ9HidM15Opdf0KkuckWh3h32UzsddvRUDY7zb/ExwVlqBnTNTqd62sNOgjTObti4iX+g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LqE7P5K1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LqE7P5K1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3ED63C2BD10; Thu, 6 Jun 2024 14:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1717683671; bh=+kOt4ntjqKiQv/f7txchd3u4wA0I2fyF+kfQj/aXP3M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LqE7P5K1kWC6VnHU9uDvG4UccicOwZSpS3P7zWmH5iz61wmyQKT+c02XdsXQvWCyj IaoN/VyPCsug6CnlsPRtDKw+3u+4xFMRpCb96sglG6QtoaATGS6wvCYEzwyXxv9rzb GUilIlp/a0nv8GZbnVj2TETn6ZtVeVbg1wqMgiAE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Judith Mendez , Adrian Hunter , Ulf Hansson , Sasha Levin Subject: [PATCH 6.6 560/744] mmc: sdhci_am654: Add tuning algorithm for delay chain Date: Thu, 6 Jun 2024 16:03:52 +0200 Message-ID: <20240606131750.427204032@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240606131732.440653204@linuxfoundation.org> References: <20240606131732.440653204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Judith Mendez [ Upstream commit 6231d99dd4119312ad41abf9383e18fec66cbe4b ] 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 Link: https://lore.kernel.org/r/20240320223837.959900-2-jm@ti.com Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- 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 967bd2dfcda1b..c3b07957736e9 100644 --- a/drivers/mmc/host/sdhci_am654.c +++ b/drivers/mmc/host/sdhci_am654.c @@ -150,10 +150,17 @@ 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; @@ -295,10 +302,13 @@ 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); + sdhci_am654->dll_enable = false; + } regmap_update_bits(sdhci_am654->base, PHY_CTRL5, CLKBUFSEL_MASK, sdhci_am654->clkbuf_sel); @@ -416,39 +426,101 @@ 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; -- 2.43.0