From patchwork Mon Aug 23 13:05:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kewei Xu X-Patchwork-Id: 501657 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham 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 30EB6C4320E for ; Mon, 23 Aug 2021 13:05:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 174B4604AC for ; Mon, 23 Aug 2021 13:05:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237321AbhHWNGi (ORCPT ); Mon, 23 Aug 2021 09:06:38 -0400 Received: from mailgw01.mediatek.com ([60.244.123.138]:47934 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S237333AbhHWNGg (ORCPT ); Mon, 23 Aug 2021 09:06:36 -0400 X-UUID: 48ef46ac57a24f93a249b1e5f371a3b7-20210823 X-UUID: 48ef46ac57a24f93a249b1e5f371a3b7-20210823 Received: from mtkmbs10n1.mediatek.inc [(172.21.101.34)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 713664978; Mon, 23 Aug 2021 21:05:49 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 23 Aug 2021 21:05:47 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 23 Aug 2021 21:05:46 +0800 From: Kewei Xu To: CC: , , , , , , , , , , , , , , Subject: [PATCH 7/7] i2c: mediatek: modify bus speed calculation formula Date: Mon, 23 Aug 2021 21:05:37 +0800 Message-ID: <1629723937-10839-8-git-send-email-kewei.xu@mediatek.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1629723937-10839-1-git-send-email-kewei.xu@mediatek.com> References: <1629723937-10839-1-git-send-email-kewei.xu@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org When clock-div is 0 or greater than 1, the bus speed calculated by the old speed calculation formula will be larger than the target speed. So we update the formula. Signed-off-by: Kewei Xu --- drivers/i2c/busses/i2c-mt65xx.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 18b5659..0b42acd8 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -69,11 +69,12 @@ #define I2C_DEFAULT_CLK_DIV 5 #define MAX_SAMPLE_CNT_DIV 8 #define MAX_STEP_CNT_DIV 64 -#define MAX_CLOCK_DIV 256 +#define MAX_CLOCK_DIV_8BITS 256 +#define MAX_CLOCK_DIV_5BITS 32 #define MAX_HS_STEP_CNT_DIV 8 -#define I2C_STANDARD_MODE_BUFFER (1000 / 2) -#define I2C_FAST_MODE_BUFFER (300 / 2) -#define I2C_FAST_MODE_PLUS_BUFFER (20 / 2) +#define I2C_STANDARD_MODE_BUFFER (1000 / 3) +#define I2C_FAST_MODE_BUFFER (300 / 3) +#define I2C_FAST_MODE_PLUS_BUFFER (20 / 3) #define I2C_CONTROL_RS (0x1 << 1) #define I2C_CONTROL_DMA_EN (0x1 << 2) @@ -725,14 +726,26 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, unsigned int best_mul; unsigned int cnt_mul; int ret = -EINVAL; + int clock_div_constraint = 0; if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ) target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ; + if (i2c->use_default_timing) { + clock_div_constraint = 0; + } else if (i2c->dev_comp->ltiming_adjust && + i2c->ac_timing.inter_clk_div > 1) { + clock_div_constraint = 1; + } else if (i2c->dev_comp->ltiming_adjust && + i2c->ac_timing.inter_clk_div == 0) { + clock_div_constraint = -1; + } + max_step_cnt = mtk_i2c_max_step_cnt(target_speed); base_step_cnt = max_step_cnt; /* Find the best combination */ - opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed); + opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed) + + clock_div_constraint; best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt; /* Search for the best pair (sample_cnt, step_cnt) with @@ -767,7 +780,8 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, sample_cnt = base_sample_cnt; step_cnt = base_step_cnt; - if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) { + if ((clk_src / (2 * (sample_cnt * step_cnt - clock_div_constraint))) > + target_speed) { /* In this case, hardware can't support such * low i2c_bus_freq */ @@ -854,13 +868,16 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c, target_speed = i2c->speed_hz; parent_clk /= i2c->clk_src_div; - if (i2c->dev_comp->timing_adjust) - max_clk_div = MAX_CLOCK_DIV; + if (i2c->dev_comp->timing_adjust && i2c->dev_comp->ltiming_adjust) + max_clk_div = MAX_CLOCK_DIV_5BITS; + else if (i2c->dev_comp->timing_adjust) + max_clk_div = MAX_CLOCK_DIV_8BITS; else max_clk_div = 1; for (clk_div = 1; clk_div <= max_clk_div; clk_div++) { clk_src = parent_clk / clk_div; + i2c->ac_timing.inter_clk_div = clk_div - 1; if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) { /* Set master code speed register */ @@ -907,8 +924,6 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c, break; } - i2c->ac_timing.inter_clk_div = clk_div - 1; - return 0; }