Thread (7 messages) 7 messages, 3 authors, 2017-02-23

Re: [PATCH 2/2] [2/2] mmc: sdhci-cadence: Update PHY delay configuration

From: Ulf Hansson <hidden>
Date: 2017-02-16 15:10:04
Also in: linux-mmc, lkml

On 16 February 2017 at 14:06, Piotr Sroka [off-list ref] wrote:
DTS properties are used instead of fixed data
because PHY settings can be different for different platforms.
Configuration of new three PHY delays were added

Signed-off-by: Piotr Sroka <redacted>
---
 .../devicetree/bindings/mmc/sdhci-cadence.txt      | 54 ++++++++++++++
Please split this patch.

DT docs should be a separate patch and make sure it precedes the
changes where the new bindings are being parsed in the driver code.
quoted hunk ↗ jump to hunk
 drivers/mmc/host/sdhci-cadence.c                   | 83 +++++++++++++++++++---
 2 files changed, 129 insertions(+), 8 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
index c0f37cb..221d3fe 100644
--- a/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
+++ b/Documentation/devicetree/bindings/mmc/sdhci-cadence.txt
@@ -19,6 +19,59 @@ if supported.  See mmc.txt for details.
 - mmc-hs400-1_8v
 - mmc-hs400-1_2v

+- phy-input-delay-sd-hs:
+  Value of the delay in the input path for High Speed work mode.
+  Valid range = [0:0x1F].
Please specify what unit this in. And then also a suffix, like "-ns"
to the name of the binding.

Similar comment applies to all new bindings below.
+  Delay configuration stay unchanged if this property is not provided.
I would remove this information from the DT doc, it's just confusion
when you refer to something that should remain "unchanged".

Similar comment applies to all new bindings below.
+- phy-input-delay-sd-default:
+  Value of the delay in the input path for Default Speed work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-sd-sdr12:
+  Value of the delay in the input path for SDR12 work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-sd-sdr25:
+  Value of the delay in the input path for SDR25 work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-sd-sdr50:
+  Value of the delay in the input path for SDR50 work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-sd-ddr50:
+  Value of the delay in the input path for DDR50 work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-emmc-legacy:
Legacy? As in legacy speed mode?
+  Value of the delay in the input path for eMMC legacy work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-emmc-sdr:
+  Value of the delay in the input path for eMMC SDR work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-input-delay-emmc-ddr:
+  Value of the delay in the input path for eMMC DDR work mode.
+  Valid range = [0:0x1F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-dll-delay-sdclk:
+  Value of the delay introduced on the sdclk output
+  for all modes except HS200, HS400 and HS400_ES.
+  Valid range = [0:0x7F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-dll-delay-sdclk-hsmmc:
+  Value of the delay introduced on the sdclk output
+  for HS200, HS400 and HS400_ES speed modes.
+  Valid range = [0:0x7F].
+  Delay configuration stay unchanged if this property is not provided.
+- phy-dll-delay-strobe:
+  Value of the delay introduced on the dat_strobe input
+  used in HS400 / HS400_ES speed modes.
+  Valid range = [0:0x7F].
+  Delay configuration stay unchanged if this property is not provided.
A general comment, is that I suggest you look at the generic mmc DT
bindings for the different speedmodes, and align these new names of DT
bindings to those.
quoted hunk ↗ jump to hunk
+
+
 Example:
        emmc: sdhci@5a000000 {
                compatible = "socionext,uniphier-sd4hc", "cdns,sd4hc";
@@ -29,4 +82,5 @@ Example:
                mmc-ddr-1_8v;
                mmc-hs200-1_8v;
                mmc-hs400-1_8v;
+               phy-input-delay-sd-hs = <0>;
        };
diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c
index c946e45..6c338d2 100644
--- a/drivers/mmc/host/sdhci-cadence.c
+++ b/drivers/mmc/host/sdhci-cadence.c
@@ -17,6 +17,7 @@
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/mmc/host.h>
+#include <linux/of.h>

 #include "sdhci-pltfm.h"
@@ -53,6 +54,9 @@
 #define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY 0x06
 #define SDHCI_CDNS_PHY_DLY_EMMC_SDR    0x07
 #define SDHCI_CDNS_PHY_DLY_EMMC_DDR    0x08
+#define SDHCI_CDNS_PHY_DLY_SDCLK       0x0b
+#define SDHCI_CDNS_PHY_DLY_HSMMC       0x0c
+#define SDHCI_CDNS_PHY_DLY_STROBE      0x0d

 /*
  * The tuned val register is 6 bit-wide, but not the whole of the range is
@@ -89,13 +93,73 @@ static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
        return 0;
 }

-static void sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
+static int sdhci_cdns_phy_parse_dt(struct device_node *np,
+                                  struct sdhci_cdns_priv *priv)
 {
-       sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_HS, 4);
-       sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_SD_DEFAULT, 4);
-       sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_LEGACY, 9);
-       sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_SDR, 2);
-       sdhci_cdns_write_phy_reg(priv, SDHCI_CDNS_PHY_DLY_EMMC_DDR, 3);
+       u32 tmp;
+       int ret;
+
+       if (!of_property_read_u32(np, "phy-input-delay-sd-hs", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_SD_HS, tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-input-delay-sd-default", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_SD_DEFAULT,
+                                              tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-input-delay-sd-sdr12", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_UHS_SDR12,
+                                              tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-input-delay-sd-sdr25", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_UHS_SDR25,
+                                              tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-input-delay-sd-sdr50", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_UHS_SDR50,
+                                              tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-input-delay-sd-ddr50", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_UHS_DDR50,
+                                              tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-dll-delay-sdclk", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_SDCLK, tmp);
+
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-dll-delay-sdclk-hsmmc", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_HSMMC, tmp);
+               if (ret)
+                       return ret;
+       }
+       if (!of_property_read_u32(np, "phy-dll-delay-strobe", &tmp)) {
+               ret = sdhci_cdns_write_phy_reg(priv,
+                                              SDHCI_CDNS_PHY_DLY_STROBE, tmp);
+               if (ret)
+                       return ret;
+       }
+       return 0;
This all looks very weird. Should you write all this to the phy
register, even before you know anything about what kind of
eMMC/MMC/SD/SDIO card that is attached? Does that even work?
quoted hunk ↗ jump to hunk
 }

 static inline void *sdhci_cdns_priv(struct sdhci_host *host)
@@ -224,10 +288,11 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        struct sdhci_host *host;
        struct sdhci_pltfm_host *pltfm_host;
        struct sdhci_cdns_priv *priv;
+       struct device *dev = &pdev->dev;
        struct clk *clk;
        int ret;

-       clk = devm_clk_get(&pdev->dev, NULL);
+       clk = devm_clk_get(dev, NULL);
This seems like and unrelated change. Please remove this change from the patch.
quoted hunk ↗ jump to hunk
        if (IS_ERR(clk))
                return PTR_ERR(clk);
@@ -253,7 +318,9 @@ static int sdhci_cdns_probe(struct platform_device *pdev)
        if (ret)
                goto free;

-       sdhci_cdns_phy_init(priv);
+       ret = sdhci_cdns_phy_parse_dt(dev->of_node, priv);
+       if (ret)
+               goto free;

        ret = sdhci_add_host(host);
        if (ret)
--
2.2.2
Kind regards
Uffe
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