Re: [PATCH 04/12] mci: arasan: read clk phases from DT

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

On 08.03.24 12:17, Steffen Trumtrar wrote:
> Depending on the used SDHCI mode the clock phases are different.
> Import the helper function to get these values from the DT from linux v6.7.
> 
> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> ---
>  drivers/mci/arasan-sdhci.c | 121 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 121 insertions(+)
> 
> diff --git a/drivers/mci/arasan-sdhci.c b/drivers/mci/arasan-sdhci.c
> index cc1bad8b62..76022708cd 100644
> --- a/drivers/mci/arasan-sdhci.c
> +++ b/drivers/mci/arasan-sdhci.c
> @@ -30,10 +30,33 @@
>  #define SDHCI_ARASAN_BUS_WIDTH			4
>  #define TIMEOUT_VAL				0xE
>  
> +#define ZYNQMP_CLK_PHASES			10
> +#define ZYNQMP_CLK_PHASE_UHS_SDR104		6
> +#define ZYNQMP_CLK_PHASE_HS200			9
> +/* Default settings for ZynqMP Clock Phases */
> +#define ZYNQMP_ICLK_PHASE {0, 63, 63, 0, 63,  0,   0, 183, 54,  0, 0}
> +#define ZYNQMP_OCLK_PHASE {0, 72, 60, 0, 60, 72, 135, 48, 72, 135, 0}

"include: mci: sync mci_timing with linux" should be ordered before this
patch, because the above two lines depend on it for correctness.

> +
> +/**
> + * struct sdhci_arasan_clk_data - Arasan Controller Clock Data.
> + *
> + * @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
> + * @clk_of_data:	Platform specific runtime clock data storage pointer
> + */
> +struct sdhci_arasan_clk_data {
> +	int		clk_phase_in[ZYNQMP_CLK_PHASES + 1];
> +	int		clk_phase_out[ZYNQMP_CLK_PHASES + 1];
> +	void		(*set_clk_delays)(struct sdhci *host);
> +	void		*clk_of_data;
> +};
> +
>  struct arasan_sdhci_host {
>  	struct mci_host		mci;
>  	struct sdhci		sdhci;
>  	unsigned int		quirks; /* Arasan deviations from spec */
> +	struct sdhci_arasan_clk_data clk_data;
>  /* Controller does not have CD wired and will not function normally without */
>  #define SDHCI_ARASAN_QUIRK_FORCE_CDTEST		BIT(0)
>  #define SDHCI_ARASAN_QUIRK_NO_1_8_V		BIT(1)
> @@ -119,6 +142,7 @@ static int arasan_sdhci_init(struct mci_host *mci, struct device *dev)
>  static void arasan_sdhci_set_clock(struct mci_host *mci, unsigned int clock)
>  {
>  	struct arasan_sdhci_host *host = to_arasan_sdhci_host(mci);
> +	struct sdhci_arasan_clk_data *clk_data = &host->clk_data;
>  
>  	if (host->quirks & SDHCI_ARASAN_QUIRK_CLOCK_25_BROKEN) {
>  		/*
> @@ -219,6 +243,101 @@ static int arasan_sdhci_send_cmd(struct mci_host *mci, struct mci_cmd *cmd,
>  	return ret;
>  }
>  
> +static void sdhci_arasan_set_clk_delays(struct sdhci *host)
> +{
> +	struct arasan_sdhci_host *arasan_sdhci = sdhci_to_arasan(host);
> +	struct mci_host *mci = &arasan_sdhci->mci;
> +	struct sdhci_arasan_clk_data *clk_data = &arasan_sdhci->clk_data;
> +
> +}
> +
> +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;
> +
> +	u32 clk_phase[2] = {0};
> +	int ret;
> +
> +	/*
> +	 * Read Tap Delay values from DT, if the DT does not contain the
> +	 * Tap Values then use the pre-defined values.
> +	 */
> +	ret = of_property_read_u32_array(np, prop, &clk_phase[0], 2);
> +	if (ret < 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
> + *
> + * @dev:		Pointer to our struct device.
> + * @clk_data:		Pointer to the Clock Data structure
> + *
> + * Called at initialization to parse the values of Clock Delays.
> + */
> +static void arasan_dt_parse_clk_phases(struct device *dev,
> +				       struct sdhci_arasan_clk_data *clk_data)
> +{
> +	u32 mio_bank = 0;
> +	int i;
> +
> +	/*
> +	 * 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;
> +
> +	if (of_device_is_compatible(dev->of_node, "xlnx,zynqmp-8.9a")) {
> +		u32 zynqmp_iclk_phase[ZYNQMP_CLK_PHASES + 1] = ZYNQMP_ICLK_PHASE;
> +		u32 zynqmp_oclk_phase[ZYNQMP_CLK_PHASES + 1] = ZYNQMP_OCLK_PHASE;
> +
> +		of_property_read_u32(dev->of_node, "xlnx,mio-bank", &mio_bank);
> +		if (mio_bank == 2) {
> +			zynqmp_oclk_phase[ZYNQMP_CLK_PHASE_UHS_SDR104] = 90;
> +			zynqmp_oclk_phase[ZYNQMP_CLK_PHASE_HS200] = 90;
> +		}
> +
> +		for (i = 0; i <= ZYNQMP_CLK_PHASES; i++) {
> +			clk_data->clk_phase_in[i] = zynqmp_iclk_phase[i];
> +			clk_data->clk_phase_out[i] = zynqmp_oclk_phase[i];
> +		}
> +	}
> +
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_LEGACY,
> +				 "clk-phase-legacy");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS,
> +				 "clk-phase-mmc-hs");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_SD_HS,
> +				 "clk-phase-sd-hs");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR12,
> +				 "clk-phase-uhs-sdr12");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR25,
> +				 "clk-phase-uhs-sdr25");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR50,
> +				 "clk-phase-uhs-sdr50");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_SDR104,
> +				 "clk-phase-uhs-sdr104");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_UHS_DDR50,
> +				 "clk-phase-uhs-ddr50");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_DDR52,
> +				 "clk-phase-mmc-ddr52");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS200,
> +				 "clk-phase-mmc-hs200");
> +	arasan_dt_read_clk_phase(dev, clk_data, MMC_TIMING_MMC_HS400,
> +				 "clk-phase-mmc-hs400");
> +}
> +
>  static int arasan_sdhci_probe(struct device *dev)
>  {
>  	struct device_node *np = dev->of_node;
> @@ -281,6 +400,8 @@ static int arasan_sdhci_probe(struct device *dev)
>  	mci->f_max = clk_get_rate(clk_xin);
>  	mci->f_min = 50000000 / 256;
>  
> +	arasan_dt_parse_clk_phases(dev, &arasan_sdhci->clk_data);
> +
>  	/* parse board supported bus width capabilities */
>  	mci_of_parse(&arasan_sdhci->mci);
>  
> 

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