From patchwork Tue Sep 12 10:03:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vaishnav Achath X-Patchwork-Id: 13381243 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AA666CA0ECA for ; Tue, 12 Sep 2023 10:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232412AbjILKDi (ORCPT ); Tue, 12 Sep 2023 06:03:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229675AbjILKDi (ORCPT ); Tue, 12 Sep 2023 06:03:38 -0400 Received: from lelv0142.ext.ti.com (lelv0142.ext.ti.com [198.47.23.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 303AAE64; Tue, 12 Sep 2023 03:03:34 -0700 (PDT) Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 38CA3UV1116989; Tue, 12 Sep 2023 05:03:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1694513010; bh=KA2XnqOK+ONLJH10k5Lo63EiIrHgI5+3v8/OqVOOu+k=; h=From:To:CC:Subject:Date; b=szCKTURAHJll2IAenooYr2ZOeeLTCTQJvI3IjsLVuuVElTsm9gIsqYjPE9ZcB8UB7 P35PWRhDQeo9GbEZxyP9U0kkr+Fpwa0MmZt35/rAIP/FWgGkbBON+dHHJicvGAalrs mSdV3/EsthbWKNlIrI5MIgrKslEpNz5/EFFAnTC8= Received: from DLEE113.ent.ti.com (dlee113.ent.ti.com [157.170.170.24]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 38CA3U80130267 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 12 Sep 2023 05:03:30 -0500 Received: from DLEE107.ent.ti.com (157.170.170.37) by DLEE113.ent.ti.com (157.170.170.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 12 Sep 2023 05:03:29 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE107.ent.ti.com (157.170.170.37) 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; Tue, 12 Sep 2023 05:03:29 -0500 Received: from localhost (ileaxei01-snat2.itg.ti.com [10.180.69.6]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 38CA3S6L074562; Tue, 12 Sep 2023 05:03:29 -0500 From: Vaishnav Achath To: , CC: , , , , , Subject: [PATCH] spi: omap2-mcspi: Fix hardcoded reference clock Date: Tue, 12 Sep 2023 15:33:28 +0530 Message-ID: <20230912100328.31813-1-vaishnav.a@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org A hardcoded reference clock of 48 MHz is used to calculate the clock divisor values, but the reference clock frequency can be different across devices and can be configured which can cause a mismatch between the reported frequency and actual SPI clock frequency observed. Fix this by fetching the clock rate from the clock provider and falling back to hardcoded reference only if the clock is not supplied. Fixes: 2cd7d393f461 ("arm64: dts: ti: k3-am654: Add McSPI DT nodes") Signed-off-by: Vaishnav Achath --- Blamed commit is the first device where the default reference clock was different from the hardcoded value. Tested on TDA4VM SK (6.6.0-rc1-next-20230911) drivers/spi/spi-omap2-mcspi.c | 31 ++++++++++++++++++++----------- 1 file changed, 20 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index e5cd82eb9e54..6ec45fd0e904 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -125,8 +125,10 @@ struct omap2_mcspi { struct omap2_mcspi_dma *dma_channels; struct device *dev; struct omap2_mcspi_regs ctx; + struct clk *clk; int fifo_depth; bool slave_aborted; + unsigned int ref_clk_hz; unsigned int pin_dir:1; size_t max_xfer_len; }; @@ -880,12 +882,12 @@ omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer) return count - c; } -static u32 omap2_mcspi_calc_divisor(u32 speed_hz) +static u32 omap2_mcspi_calc_divisor(u32 speed_hz, u32 ref_clk_hz) { u32 div; for (div = 0; div < 15; div++) - if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div)) + if (speed_hz >= (ref_clk_hz >> div)) return div; return 15; @@ -897,7 +899,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi, { struct omap2_mcspi_cs *cs = spi->controller_state; struct omap2_mcspi *mcspi; - u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0; + u32 ref_clk_hz, l = 0, clkd = 0, div, extclk = 0, clkg = 0; u8 word_len = spi->bits_per_word; u32 speed_hz = spi->max_speed_hz; @@ -911,14 +913,15 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi, if (t && t->speed_hz) speed_hz = t->speed_hz; - speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ); - if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) { - clkd = omap2_mcspi_calc_divisor(speed_hz); - speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd; + ref_clk_hz = mcspi->ref_clk_hz; + speed_hz = min_t(u32, speed_hz, ref_clk_hz); + if (speed_hz < (ref_clk_hz / OMAP2_MCSPI_MAX_DIVIDER)) { + clkd = omap2_mcspi_calc_divisor(speed_hz, ref_clk_hz); + speed_hz = ref_clk_hz >> clkd; clkg = 0; } else { - div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz; - speed_hz = OMAP2_MCSPI_MAX_FREQ / div; + div = (ref_clk_hz + speed_hz - 1) / speed_hz; + speed_hz = ref_clk_hz / div; clkd = (div - 1) & 0xf; extclk = (div - 1) >> 4; clkg = OMAP2_MCSPI_CHCONF_CLKG; @@ -1448,8 +1451,6 @@ static int omap2_mcspi_probe(struct platform_device *pdev) master->cleanup = omap2_mcspi_cleanup; master->slave_abort = omap2_mcspi_slave_abort; master->dev.of_node = node; - master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ; - master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15; master->use_gpio_descriptors = true; platform_set_drvdata(pdev, master); @@ -1519,6 +1520,14 @@ static int omap2_mcspi_probe(struct platform_device *pdev) goto free_master; } + mcspi->clk = devm_clk_get_optional_enabled(&pdev->dev, NULL); + if (mcspi->clk) + mcspi->ref_clk_hz = clk_get_rate(mcspi->clk); + else + mcspi->ref_clk_hz = OMAP2_MCSPI_MAX_FREQ; + master->max_speed_hz = mcspi->ref_clk_hz; + master->min_speed_hz = mcspi->ref_clk_hz >> 15; + pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); pm_runtime_enable(&pdev->dev);