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Message-ID: <CAPDyKFqsuzT9NXARMJtey_kZ0y2GsdOxZGsjbodWA1EXw_ZSzw@mail.gmail.com>
Date: Thu, 16 Feb 2017 16:09:59 +0100
From: Ulf Hansson <ulf.hansson@...aro.org>
To: Piotr Sroka <piotrs@...ence.com>
Cc: "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Adrian Hunter <adrian.hunter@...el.com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>
Subject: Re: [PATCH 2/2] [2/2] mmc: sdhci-cadence: Update PHY delay configuration
On 16 February 2017 at 14:06, Piotr Sroka <piotrs@...ence.com> 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 <piotrs@...ence.com>
> ---
> .../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.
> 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.
> +
> +
> Example:
> emmc: sdhci@...00000 {
> 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?
> }
>
> 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.
> 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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