From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manish Narani Subject: [PATCH v4 5/8] mmc: sdhci-of-arasan: Add support to set clock phase delays for SD Date: Tue, 29 Oct 2019 16:00:39 +0530 Message-ID: <1572345042-101207-5-git-send-email-manish.narani@xilinx.com> References: <1572345042-101207-1-git-send-email-manish.narani@xilinx.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1572345042-101207-1-git-send-email-manish.narani@xilinx.com> Sender: linux-kernel-owner@vger.kernel.org To: ulf.hansson@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, adrian.hunter@intel.com, michal.simek@xilinx.com, jolly.shah@xilinx.com, nava.manne@xilinx.com, rajan.vaja@xilinx.com, manish.narani@xilinx.com Cc: linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, git@xilinx.com List-Id: linux-mmc@vger.kernel.org Add support to read Clock Phase Delays from the DT and set it via clk_set_phase() API from clock framework. Some of the controllers might have their own handling of setting clock delays, for this keep the set_clk_delays as function pointer which can be assigned controller specific handling of the same. Signed-off-by: Manish Narani --- drivers/mmc/host/sdhci-of-arasan.c | 91 ++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c index b75ba780f902..18eb6cffd269 100644 --- a/drivers/mmc/host/sdhci-of-arasan.c +++ b/drivers/mmc/host/sdhci-of-arasan.c @@ -77,12 +77,18 @@ struct sdhci_arasan_soc_ctl_map { * @sdcardclk: Pointer to normal 'struct clock' for sdcardclk_hw. * @sampleclk_hw: Struct for the clock we might provide to a PHY. * @sampleclk: Pointer to normal 'struct clock' for sampleclk_hw. + * @clk_phase_in: Array of Input Clock Phase Delays for all speed modes + * @clk_phase_out: Array of Output Clock Phase Delays for all speed modes + * @set_clk_delays: Function pointer for setting Clock Delays */ struct sdhci_arasan_clk_data { struct clk_hw sdcardclk_hw; struct clk *sdcardclk; struct clk_hw sampleclk_hw; struct clk *sampleclk; + int clk_phase_in[MMC_TIMING_MMC_HS400 + 1]; + int clk_phase_out[MMC_TIMING_MMC_HS400 + 1]; + void (*set_clk_delays)(struct sdhci_host *host); }; /** @@ -186,6 +192,7 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); + struct sdhci_arasan_clk_data *clk_data = &sdhci_arasan->clk_data; bool ctrl_phy = false; if (!IS_ERR(sdhci_arasan->phy)) { @@ -227,6 +234,10 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) sdhci_arasan->is_phy_on = false; } + /* Set the Input and Output Clock Phase Delays */ + if (clk_data->set_clk_delays) + clk_data->set_clk_delays(host); + sdhci_set_clock(host, clock); if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE) @@ -650,6 +661,84 @@ static void sdhci_arasan_update_baseclkfreq(struct sdhci_host *host) sdhci_arasan_syscon_write(host, &soc_ctl_map->baseclkfreq, mhz); } +static void sdhci_arasan_set_clk_delays(struct sdhci_host *host) +{ + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host); + struct sdhci_arasan_clk_data *clk_data = &sdhci_arasan->clk_data; + + clk_set_phase(clk_data->sampleclk, + clk_data->clk_phase_in[host->timing]); + clk_set_phase(clk_data->sdcardclk, + clk_data->clk_phase_out[host->timing]); +} + +static void arasan_dt_read_clk_phase(struct device *dev, + struct sdhci_arasan_clk_data *clk_data, + unsigned int timing, const char *prop) +{ + struct device_node *np = dev->of_node; + + int clk_phase[2] = {0}; + + /* + * Read Tap Delay values from DT, if the DT does not contain the + * Tap Values then use the pre-defined values. + */ + if (of_property_read_variable_u32_array(np, prop, &clk_phase[0], + 2, 0)) { + dev_dbg(dev, "Using predefined clock phase for %s = %d %d\n", + prop, clk_data->clk_phase_in[timing], + clk_data->clk_phase_out[timing]); + return; + } + + /* The values read are Input and Output Clock Delays in order */ + clk_data->clk_phase_in[timing] = clk_phase[0]; + clk_data->clk_phase_out[timing] = clk_phase[1]; +} + +/** + * arasan_dt_parse_clk_phases - Read Clock Delay values from DT + * + * Called at initialization to parse the values of Clock Delays. + * + * @dev: Pointer to our struct device. + */ +static void arasan_dt_parse_clk_phases(struct device *dev, + struct sdhci_arasan_clk_data *clk_data) +{ + /* + * This has been kept as a pointer and is assigned a function here. + * So that different controller variants can assign their own handling + * function. + */ + clk_data->set_clk_delays = sdhci_arasan_set_clk_delays; + + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_LEGACY, + "arasan-clk-phase-legacy"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS, + "arasan-clk-phase-mmc-hs"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_SD_HS, + "arasan-clk-phase-sd-hs"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR12, + "arasan-clk-phase-uhs-sdr12"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR25, + "arasan-clk-phase-uhs-sdr25"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR50, + "arasan-clk-phase-uhs-sdr50"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR104, + "arasan-clk-phase-uhs-sdr104"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_DDR50, + "arasan-clk-phase-uhs-ddr50"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_DDR52, + "arasan-clk-phase-mmc-ddr52"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS200, + "arasan-clk-phase-mmc-hs200"); + arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS400, + "arasan-clk-phase-mmc-hs400"); +} + /** * sdhci_arasan_register_sdcardclk - Register the sdcardclk for a PHY to use * @@ -942,6 +1031,8 @@ static int sdhci_arasan_probe(struct platform_device *pdev) if (ret) goto clk_disable_all; + arasan_dt_parse_clk_phases(&pdev->dev, &sdhci_arasan->clk_data); + ret = mmc_of_parse(host->mmc); if (ret) { if (ret != -EPROBE_DEFER) -- 2.17.1