Re: [PATCH 3/3] mmc: sdhci-of-arasan: Add support for ZynqMP Platform Tap Delays Setup

From: Adrian Hunter
Date: Thu Jun 13 2019 - 11:38:19 EST


On 11/06/19 12:56 PM, Manish Narani wrote:
> Apart from taps set by auto tuning, ZynqMP platform has feature to set
> the tap values manually. Add support to read tap delay values from
> DT and set the same in HW via ZynqMP SoC framework. Reading Tap
> Delays from DT is optional, if the property is not available in DT the
> driver will use the pre-defined Tap Delay Values.
>
> Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>

OK for SDHCI:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>


> ---
> drivers/mmc/host/sdhci-of-arasan.c | 173 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 172 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
> index b12abf9..7af6cec 100644
> --- a/drivers/mmc/host/sdhci-of-arasan.c
> +++ b/drivers/mmc/host/sdhci-of-arasan.c
> @@ -22,6 +22,7 @@
> #include <linux/phy/phy.h>
> #include <linux/regmap.h>
> #include <linux/of.h>
> +#include <linux/firmware/xlnx-zynqmp.h>
>
> #include "cqhci.h"
> #include "sdhci-pltfm.h"
> @@ -32,6 +33,10 @@
>
> #define PHY_CLK_TOO_SLOW_HZ 400000
>
> +/* Default settings for ZynqMP Tap Delays */
> +#define ZYNQMP_ITAP_DELAYS {0, 0x15, 0x15, 0, 0x15, 0, 0, 0x3D, 0x12, 0, 0}
> +#define ZYNQMP_OTAP_DELAYS {0, 0x5, 0x6, 0, 0x5, 0x3, 0x3, 0x4, 0x6, 0x3, 0}
> +
> /*
> * On some SoCs the syscon area has a feature where the upper 16-bits of
> * each 32-bit register act as a write mask for the lower 16-bits. This allows
> @@ -81,6 +86,7 @@ struct sdhci_arasan_soc_ctl_map {
> * @sdcardclk: Pointer to normal 'struct clock' for sdcardclk_hw.
> * @soc_ctl_base: Pointer to regmap for syscon for soc_ctl registers.
> * @soc_ctl_map: Map to get offsets into soc_ctl registers.
> + * @of_data: Platform specific runtime data storage pointer
> */
> struct sdhci_arasan_data {
> struct sdhci_host *host;
> @@ -101,6 +107,15 @@ struct sdhci_arasan_data {
> /* Controller immediately reports SDHCI_CLOCK_INT_STABLE after enabling the
> * internal clock even when the clock isn't stable */
> #define SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE BIT(1)
> +
> + void *of_data;
> +};
> +
> +struct sdhci_arasan_zynqmp_data {
> + void (*set_tap_delay)(struct sdhci_host *host);
> + const struct zynqmp_eemi_ops *eemi_ops;
> + u8 tapdly[MMC_TIMING_MMC_HS400 + 1][2]; /* [0] for input delay, */
> + /* [1] for output delay */
> };
>
> struct sdhci_arasan_of_data {
> @@ -209,6 +224,16 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock)
> sdhci_arasan->is_phy_on = false;
> }
>
> + /* Set the Input and Output Tap Delays */
> + if (host->version >= SDHCI_SPEC_300 &&
> + host->timing != MMC_TIMING_LEGACY &&
> + host->timing != MMC_TIMING_UHS_SDR12) {
> + struct sdhci_arasan_zynqmp_data *zynqmp_data =
> + sdhci_arasan->of_data;
> + if (zynqmp_data && zynqmp_data->set_tap_delay)
> + zynqmp_data->set_tap_delay(host);
> + }
> +
> sdhci_set_clock(host, clock);
>
> if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE)
> @@ -487,6 +512,10 @@ static const struct of_device_id sdhci_arasan_of_match[] = {
> .compatible = "arasan,sdhci-4.9a",
> .data = &sdhci_arasan_data,
> },
> + {
> + .compatible = "xlnx,zynqmp-8.9a",
> + .data = &sdhci_arasan_data,
> + },
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
> @@ -517,6 +546,37 @@ static const struct clk_ops arasan_sdcardclk_ops = {
> };
>
> /**
> + * sdhci_zynqmp_sdcardclk_set_phase - Set the SD Clock Tap Delays
> + *
> + * Set the SD Clock Tap Delays for Input and Output paths
> + *
> + * @hw: Pointer to the hardware clock structure.
> + * @degrees The clock phase shift between 0 - 359.
> + * Return: 0 on success and error value on error
> + */
> +static int sdhci_zynqmp_sdcardclk_set_phase(struct clk_hw *hw, int degrees)
> +
> +{
> + struct sdhci_arasan_data *sdhci_arasan =
> + container_of(hw, struct sdhci_arasan_data, sdcardclk_hw);
> + struct sdhci_arasan_zynqmp_data *zynqmp_data = sdhci_arasan->of_data;
> + const struct zynqmp_eemi_ops *eemi_ops = zynqmp_data->eemi_ops;
> + const char *clk_name = clk_hw_get_name(hw);
> + u32 device_id = !strcmp(clk_name, "clk_sd0") ? 0 : 1;
> +
> + if (!eemi_ops->sdio_setphase)
> + return -ENODEV;
> +
> + /* Set the Clock Phase */
> + return eemi_ops->sdio_setphase(device_id, degrees);
> +}
> +
> +static const struct clk_ops zynqmp_sdcardclk_ops = {
> + .recalc_rate = sdhci_arasan_sdcardclk_recalc_rate,
> + .set_phase = sdhci_zynqmp_sdcardclk_set_phase,
> +};
> +
> +/**
> * sdhci_arasan_update_clockmultiplier - Set corecfg_clockmultiplier
> *
> * The corecfg_clockmultiplier is supposed to contain clock multiplier
> @@ -638,7 +698,10 @@ static int sdhci_arasan_register_sdclk(struct sdhci_arasan_data *sdhci_arasan,
> sdcardclk_init.parent_names = &parent_clk_name;
> sdcardclk_init.num_parents = 1;
> sdcardclk_init.flags = CLK_GET_RATE_NOCACHE;
> - sdcardclk_init.ops = &arasan_sdcardclk_ops;
> + if (of_device_is_compatible(np, "xlnx,zynqmp-8.9a"))
> + sdcardclk_init.ops = &zynqmp_sdcardclk_ops;
> + else
> + sdcardclk_init.ops = &arasan_sdcardclk_ops;
>
> sdhci_arasan->sdcardclk_hw.init = &sdcardclk_init;
> sdhci_arasan->sdcardclk =
> @@ -714,6 +777,108 @@ static int sdhci_arasan_add_host(struct sdhci_arasan_data *sdhci_arasan)
> return ret;
> }
>
> +static void sdhci_arasan_zynqmp_set_tap_delay(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_zynqmp_data *zynqmp_data = sdhci_arasan->of_data;
> +
> + clk_set_phase(sdhci_arasan->sdcardclk,
> + (int)zynqmp_data->tapdly[host->timing][0]);
> + clk_set_phase(sdhci_arasan->sdcardclk,
> + (int)zynqmp_data->tapdly[host->timing][1] +
> + INPUT_TAP_BOUNDARY);
> +}
> +
> +static void arasan_dt_read_tap_delay(struct device *dev, u8 *tapdly,
> + const char *prop, u8 itap_def, u8 otap_def)
> +{
> + struct device_node *np = dev->of_node;
> +
> + tapdly[0] = itap_def;
> + tapdly[1] = otap_def;
> +
> + /*
> + * 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_u8_array(np, prop, &tapdly[0], 2, 0)) {
> + dev_dbg(dev, "Using predefined tapdly for %s = %d %d\n",
> + prop, tapdly[0], tapdly[1]);
> + }
> +}
> +
> +/**
> + * arasan_dt_parse_tap_delays - Read Tap Delay values from DT
> + *
> + * Called at initialization to parse the values of Tap Delays.
> + *
> + * @dev: Pointer to our struct device.
> + */
> +static int arasan_dt_parse_tap_delays(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct sdhci_host *host = platform_get_drvdata(pdev);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
> + struct sdhci_arasan_zynqmp_data zynqmp_data;
> + const struct zynqmp_eemi_ops *eemi_ops;
> + u8 *itapdly, *otapdly;
> + u32 mio_bank = 0;
> +
> + eemi_ops = zynqmp_pm_get_eemi_ops();
> + if (IS_ERR(eemi_ops))
> + return PTR_ERR(eemi_ops);
> +
> + itapdly = (u8 [MMC_TIMING_MMC_HS400 + 1]) ZYNQMP_ITAP_DELAYS;
> + otapdly = (u8 [MMC_TIMING_MMC_HS400 + 1]) ZYNQMP_OTAP_DELAYS;
> +
> + of_property_read_u32(pdev->dev.of_node, "xlnx,mio-bank", &mio_bank);
> + if (mio_bank == 2) {
> + otapdly[MMC_TIMING_UHS_SDR104] = 0x2;
> + otapdly[MMC_TIMING_MMC_HS200] = 0x2;
> + }
> +
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_MMC_HS],
> + "xlnx,tap-delay-mmc-hsd",
> + itapdly[MMC_TIMING_MMC_HS],
> + otapdly[MMC_TIMING_MMC_HS]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_SD_HS],
> + "xlnx,tap-delay-sd-hsd",
> + itapdly[MMC_TIMING_SD_HS],
> + otapdly[MMC_TIMING_SD_HS]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_UHS_SDR25],
> + "xlnx,tap-delay-sdr25",
> + itapdly[MMC_TIMING_UHS_SDR25],
> + otapdly[MMC_TIMING_UHS_SDR25]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_UHS_SDR50],
> + "xlnx,tap-delay-sdr50",
> + itapdly[MMC_TIMING_UHS_SDR50],
> + otapdly[MMC_TIMING_UHS_SDR50]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_UHS_SDR104],
> + "xlnx,tap-delay-sdr104",
> + itapdly[MMC_TIMING_UHS_SDR104],
> + otapdly[MMC_TIMING_UHS_SDR104]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_UHS_DDR50],
> + "xlnx,tap-delay-sd-ddr50",
> + itapdly[MMC_TIMING_UHS_DDR50],
> + otapdly[MMC_TIMING_UHS_DDR50]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_MMC_DDR52],
> + "xlnx,tap-delay-mmc-ddr52",
> + itapdly[MMC_TIMING_MMC_DDR52],
> + otapdly[MMC_TIMING_MMC_DDR52]);
> + arasan_dt_read_tap_delay(dev, zynqmp_data.tapdly[MMC_TIMING_MMC_HS200],
> + "xlnx,tap-delay-mmc-hs200",
> + itapdly[MMC_TIMING_MMC_HS200],
> + otapdly[MMC_TIMING_MMC_HS200]);
> +
> + zynqmp_data.set_tap_delay = sdhci_arasan_zynqmp_set_tap_delay;
> + zynqmp_data.eemi_ops = eemi_ops;
> + sdhci_arasan->of_data = &zynqmp_data;
> +
> + return 0;
> +}
> +
> static int sdhci_arasan_probe(struct platform_device *pdev)
> {
> int ret;
> @@ -806,6 +971,12 @@ static int sdhci_arasan_probe(struct platform_device *pdev)
> goto unreg_clk;
> }
>
> + if (of_device_is_compatible(pdev->dev.of_node, "xlnx,zynqmp-8.9a")) {
> + ret = arasan_dt_parse_tap_delays(&pdev->dev);
> + if (ret)
> + goto unreg_clk;
> + }
> +
> sdhci_arasan->phy = ERR_PTR(-ENODEV);
> if (of_device_is_compatible(pdev->dev.of_node,
> "arasan,sdhci-5.1")) {
>