sdhci: arasan: Add support for Versal Tap Delays

Add support to set tap delays for Xilinx Versal SD controller. The tap
delay registers have moved to SD controller space in Versal. Make the
changes accordingly.

Signed-off-by: Manish Narani <manish.narani@xilinx.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1586195015-128992-3-git-send-email-manish.narani@xilinx.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index d4905c1..9e2ea3b 100644 (file)
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -28,15 +28,26 @@
 #include "sdhci-pltfm.h"
 
 #define SDHCI_ARASAN_VENDOR_REGISTER   0x78
+
+#define SDHCI_ARASAN_ITAPDLY_REGISTER  0xF0F8
+#define SDHCI_ARASAN_OTAPDLY_REGISTER  0xF0FC
+
 #define SDHCI_ARASAN_CQE_BASE_ADDR     0x200
 #define VENDOR_ENHANCED_STROBE         BIT(0)
 
 #define PHY_CLK_TOO_SLOW_HZ            400000
 
+#define SDHCI_ITAPDLY_CHGWIN           0x200
+#define SDHCI_ITAPDLY_ENABLE           0x100
+#define SDHCI_OTAPDLY_ENABLE           0x40
+
 /* 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}
 
+#define VERSAL_ICLK_PHASE {0, 132, 132, 0, 132, 0, 0, 162, 90, 0, 0}
+#define VERSAL_OCLK_PHASE {0,  60, 48, 0, 48, 72, 90, 36, 60, 90, 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
@@ -555,6 +566,10 @@ static const struct of_device_id sdhci_arasan_of_match[] = {
                .compatible = "xlnx,zynqmp-8.9a",
                .data = &sdhci_arasan_zynqmp_data,
        },
+       {
+               .compatible = "xlnx,versal-8.9a",
+               .data = &sdhci_arasan_zynqmp_data,
+       },
        { /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
@@ -757,6 +772,152 @@ static const struct clk_ops zynqmp_sampleclk_ops = {
        .set_phase = sdhci_zynqmp_sampleclk_set_phase,
 };
 
+/**
+ * sdhci_versal_sdcardclk_set_phase - Set the SD Output Clock Tap Delays
+ *
+ * Set the SD Output Clock Tap Delays for Output path
+ *
+ * @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_versal_sdcardclk_set_phase(struct clk_hw *hw, int degrees)
+{
+       struct sdhci_arasan_clk_data *clk_data =
+               container_of(hw, struct sdhci_arasan_clk_data, sdcardclk_hw);
+       struct sdhci_arasan_data *sdhci_arasan =
+               container_of(clk_data, struct sdhci_arasan_data, clk_data);
+       struct sdhci_host *host = sdhci_arasan->host;
+       u8 tap_delay, tap_max = 0;
+       int ret;
+
+       /*
+        * This is applicable for SDHCI_SPEC_300 and above
+        * Versal does not set phase for <=25MHz clock.
+        * If degrees is zero, no need to do anything.
+        */
+       if (host->version < SDHCI_SPEC_300 ||
+           host->timing == MMC_TIMING_LEGACY ||
+           host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
+               return 0;
+
+       switch (host->timing) {
+       case MMC_TIMING_MMC_HS:
+       case MMC_TIMING_SD_HS:
+       case MMC_TIMING_UHS_SDR25:
+       case MMC_TIMING_UHS_DDR50:
+       case MMC_TIMING_MMC_DDR52:
+               /* For 50MHz clock, 30 Taps are available */
+               tap_max = 30;
+               break;
+       case MMC_TIMING_UHS_SDR50:
+               /* For 100MHz clock, 15 Taps are available */
+               tap_max = 15;
+               break;
+       case MMC_TIMING_UHS_SDR104:
+       case MMC_TIMING_MMC_HS200:
+               /* For 200MHz clock, 8 Taps are available */
+               tap_max = 8;
+       default:
+               break;
+       }
+
+       tap_delay = (degrees * tap_max) / 360;
+
+       /* Set the Clock Phase */
+       if (tap_delay) {
+               u32 regval;
+
+               regval = sdhci_readl(host, SDHCI_ARASAN_OTAPDLY_REGISTER);
+               regval |= SDHCI_OTAPDLY_ENABLE;
+               sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
+               regval |= tap_delay;
+               sdhci_writel(host, regval, SDHCI_ARASAN_OTAPDLY_REGISTER);
+       }
+
+       return ret;
+}
+
+static const struct clk_ops versal_sdcardclk_ops = {
+       .recalc_rate = sdhci_arasan_sdcardclk_recalc_rate,
+       .set_phase = sdhci_versal_sdcardclk_set_phase,
+};
+
+/**
+ * sdhci_versal_sampleclk_set_phase - Set the SD Input Clock Tap Delays
+ *
+ * Set the SD Input Clock Tap Delays for Input path
+ *
+ * @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_versal_sampleclk_set_phase(struct clk_hw *hw, int degrees)
+{
+       struct sdhci_arasan_clk_data *clk_data =
+               container_of(hw, struct sdhci_arasan_clk_data, sampleclk_hw);
+       struct sdhci_arasan_data *sdhci_arasan =
+               container_of(clk_data, struct sdhci_arasan_data, clk_data);
+       struct sdhci_host *host = sdhci_arasan->host;
+       u8 tap_delay, tap_max = 0;
+       int ret;
+
+       /*
+        * This is applicable for SDHCI_SPEC_300 and above
+        * Versal does not set phase for <=25MHz clock.
+        * If degrees is zero, no need to do anything.
+        */
+       if (host->version < SDHCI_SPEC_300 ||
+           host->timing == MMC_TIMING_LEGACY ||
+           host->timing == MMC_TIMING_UHS_SDR12 || !degrees)
+               return 0;
+
+       switch (host->timing) {
+       case MMC_TIMING_MMC_HS:
+       case MMC_TIMING_SD_HS:
+       case MMC_TIMING_UHS_SDR25:
+       case MMC_TIMING_UHS_DDR50:
+       case MMC_TIMING_MMC_DDR52:
+               /* For 50MHz clock, 120 Taps are available */
+               tap_max = 120;
+               break;
+       case MMC_TIMING_UHS_SDR50:
+               /* For 100MHz clock, 60 Taps are available */
+               tap_max = 60;
+               break;
+       case MMC_TIMING_UHS_SDR104:
+       case MMC_TIMING_MMC_HS200:
+               /* For 200MHz clock, 30 Taps are available */
+               tap_max = 30;
+       default:
+               break;
+       }
+
+       tap_delay = (degrees * tap_max) / 360;
+
+       /* Set the Clock Phase */
+       if (tap_delay) {
+               u32 regval;
+
+               regval = sdhci_readl(host, SDHCI_ARASAN_ITAPDLY_REGISTER);
+               regval |= SDHCI_ITAPDLY_CHGWIN;
+               sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
+               regval |= SDHCI_ITAPDLY_ENABLE;
+               sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
+               regval |= tap_delay;
+               sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
+               regval &= ~SDHCI_ITAPDLY_CHGWIN;
+               sdhci_writel(host, regval, SDHCI_ARASAN_ITAPDLY_REGISTER);
+       }
+
+       return ret;
+}
+
+static const struct clk_ops versal_sampleclk_ops = {
+       .recalc_rate = sdhci_arasan_sampleclk_recalc_rate,
+       .set_phase = sdhci_versal_sampleclk_set_phase,
+};
+
 static void arasan_zynqmp_dll_reset(struct sdhci_host *host, u32 deviceid)
 {
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -954,6 +1115,16 @@ static void arasan_dt_parse_clk_phases(struct device *dev,
                }
        }
 
+       if (of_device_is_compatible(dev->of_node, "xlnx,versal-8.9a")) {
+               iclk_phase = (int [MMC_TIMING_MMC_HS400 + 1]) VERSAL_ICLK_PHASE;
+               oclk_phase = (int [MMC_TIMING_MMC_HS400 + 1]) VERSAL_OCLK_PHASE;
+
+               for (i = 0; i <= MMC_TIMING_MMC_HS400; i++) {
+                       clk_data->clk_phase_in[i] = iclk_phase[i];
+                       clk_data->clk_phase_out[i] = 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,
@@ -1014,6 +1185,8 @@ sdhci_arasan_register_sdcardclk(struct sdhci_arasan_data *sdhci_arasan,
        sdcardclk_init.flags = CLK_GET_RATE_NOCACHE;
        if (of_device_is_compatible(np, "xlnx,zynqmp-8.9a"))
                sdcardclk_init.ops = &zynqmp_sdcardclk_ops;
+       else if (of_device_is_compatible(np, "xlnx,versal-8.9a"))
+               sdcardclk_init.ops = &versal_sdcardclk_ops;
        else
                sdcardclk_init.ops = &arasan_sdcardclk_ops;
 
@@ -1066,6 +1239,8 @@ sdhci_arasan_register_sampleclk(struct sdhci_arasan_data *sdhci_arasan,
        sampleclk_init.flags = CLK_GET_RATE_NOCACHE;
        if (of_device_is_compatible(np, "xlnx,zynqmp-8.9a"))
                sampleclk_init.ops = &zynqmp_sampleclk_ops;
+       else if (of_device_is_compatible(np, "xlnx,versal-8.9a"))
+               sampleclk_init.ops = &versal_sampleclk_ops;
        else
                sampleclk_init.ops = &arasan_sampleclk_ops;