[PATCH v3] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock
Ulf Hansson
ulf.hansson at linaro.org
Wed Oct 4 01:59:44 PDT 2017
On 2 October 2017 at 16:58, Gregory CLEMENT
<gregory.clement at free-electrons.com> wrote:
> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
> is optional because not all the SoCs need them but at least for Armada
> 7K/8K it is actually mandatory.
>
> The binding documentation is updating accordingly.
>
> Without this patch the kernel hand during boot if the mvpp2.2 network
> driver was not present in the kernel. Indeed the clock needed by the
> xenon controller was set by the network driver.
>
> Fixes: 3a3748dba881 ("mmc: sdhci-xenon: Add Marvell Xenon SDHC core
> functionality)"
> CC: Stable <stable at vger.kernel.org>
> Tested-by: Zhoujie Wu <zjwu at marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
Thanks, applied for fixes!
Next time, please split DT changes into separate patches - as that
simplifies the review process.
Kind regards
Uffe
> ---
> Hi Ulf and Adrian,
>
> This patch should be merged in 4.14-rc, as it fixes real issues.
>
> This patch may looks like just as a nice clean-up but it is not. On
> the earlier version of the series adding the support for the xenon
> controller there was already this axi bus clock. But at this moment
> the documentation for the clock on the Armada 7K/8K was missing and
> there was no driver for it, so we just use the clock set by the
> bootloader and never change them that's why it worked without any
> visible problem.
>
> Then as explained in the commit log the network driver enabled the
> clock for us, and it happened that it was setup before the xenon
> driver. It is only thanks the new information we received on the
> clocks of the SoC and with more exhaustive testes that we found this
> issue and the fix for it.
>
> Thanks,
>
> Gregory
>
> Changelog:
> v2->v3:
> - remove useless test on clk pointer
> - added tested-by from Zhoujie Wu
>
> v1->v2:
> - manage the -EPROBE_DEFER case
> - remove warning message when axi clock is not present
> - remove useless test before clk_disable_unprepare()
>
> .../bindings/mmc/marvell,xenon-sdhci.txt | 12 ++++++-----
> drivers/mmc/host/sdhci-xenon.c | 24 ++++++++++++++++++----
> drivers/mmc/host/sdhci-xenon.h | 1 +
> 3 files changed, 28 insertions(+), 9 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..ed1456f5c94d 100644
> --- a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> +++ b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> @@ -16,11 +16,13 @@ Required Properties:
>
> - clocks:
> Array of clocks required for SDHC.
> - Require at least input clock for Xenon IP core.
> + Require at least input clock for Xenon IP core. For Armada AP806 and
> + CP110, the AXI clock is also mandatory.
>
> - clock-names:
> Array of names corresponding to clocks property.
> The input clock for Xenon IP core should be named as "core".
> + The input clock for the AXI bus must be named as "axi".
>
> - reg:
> * For "marvell,armada-3700-sdhci", two register areas.
> @@ -106,8 +108,8 @@ Example:
> compatible = "marvell,armada-ap806-sdhci";
> reg = <0xaa0000 0x1000>;
> interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>
> - clocks = <&emmc_clk>;
> - clock-names = "core";
> + clocks = <&emmc_clk>,<&axi_clk>;
> + clock-names = "core", "axi";
> bus-width = <4>;
> marvell,xenon-phy-slow-mode;
> marvell,xenon-tun-count = <11>;
> @@ -126,8 +128,8 @@ Example:
> interrupts = <GIC_SPI 55 IRQ_TYPE_LEVEL_HIGH>
> vqmmc-supply = <&sd_vqmmc_regulator>;
> vmmc-supply = <&sd_vmmc_regulator>;
> - clocks = <&sdclk>;
> - clock-names = "core";
> + clocks = <&sdclk>, <&axi_clk>;
> + clock-names = "core", "axi";
> bus-width = <4>;
> marvell,xenon-tun-count = <9>;
> };
> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> index 2eec2e652c53..0842bbc2d7ad 100644
> --- a/drivers/mmc/host/sdhci-xenon.c
> +++ b/drivers/mmc/host/sdhci-xenon.c
> @@ -466,6 +466,7 @@ static int xenon_probe(struct platform_device *pdev)
> {
> struct sdhci_pltfm_host *pltfm_host;
> struct sdhci_host *host;
> + struct xenon_priv *priv;
> int err;
>
> host = sdhci_pltfm_init(pdev, &sdhci_xenon_pdata,
> @@ -474,6 +475,7 @@ static int xenon_probe(struct platform_device *pdev)
> return PTR_ERR(host);
>
> pltfm_host = sdhci_priv(host);
> + priv = sdhci_pltfm_priv(pltfm_host);
>
> /*
> * Link Xenon specific mmc_host_ops function,
> @@ -491,9 +493,20 @@ static int xenon_probe(struct platform_device *pdev)
> if (err)
> goto free_pltfm;
>
> + priv->axi_clk = devm_clk_get(&pdev->dev, "axi");
> + if (IS_ERR(priv->axi_clk)) {
> + err = PTR_ERR(priv->axi_clk);
> + if (err == -EPROBE_DEFER)
> + goto err_clk;
> + } else {
> + err = clk_prepare_enable(priv->axi_clk);
> + if (err)
> + goto err_clk;
> + }
> +
> err = mmc_of_parse(host->mmc);
> if (err)
> - goto err_clk;
> + goto err_clk_axi;
>
> sdhci_get_of_property(pdev);
>
> @@ -502,11 +515,11 @@ static int xenon_probe(struct platform_device *pdev)
> /* Xenon specific dt parse */
> err = xenon_probe_dt(pdev);
> if (err)
> - goto err_clk;
> + goto err_clk_axi;
>
> err = xenon_sdhc_prepare(host);
> if (err)
> - goto err_clk;
> + goto err_clk_axi;
>
> pm_runtime_get_noresume(&pdev->dev);
> pm_runtime_set_active(&pdev->dev);
> @@ -527,6 +540,8 @@ static int xenon_probe(struct platform_device *pdev)
> pm_runtime_disable(&pdev->dev);
> pm_runtime_put_noidle(&pdev->dev);
> xenon_sdhc_unprepare(host);
> +err_clk_axi:
> + clk_disable_unprepare(priv->axi_clk);
> err_clk:
> clk_disable_unprepare(pltfm_host->clk);
> free_pltfm:
> @@ -538,6 +553,7 @@ static int xenon_remove(struct platform_device *pdev)
> {
> struct sdhci_host *host = platform_get_drvdata(pdev);
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
>
> pm_runtime_get_sync(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
> @@ -546,7 +562,7 @@ static int xenon_remove(struct platform_device *pdev)
> sdhci_remove_host(host, 0);
>
> xenon_sdhc_unprepare(host);
> -
> + clk_disable_unprepare(priv->axi_clk);
> clk_disable_unprepare(pltfm_host->clk);
>
> sdhci_pltfm_free(pdev);
> diff --git a/drivers/mmc/host/sdhci-xenon.h b/drivers/mmc/host/sdhci-xenon.h
> index 2bc0510c0769..9994995c7c56 100644
> --- a/drivers/mmc/host/sdhci-xenon.h
> +++ b/drivers/mmc/host/sdhci-xenon.h
> @@ -83,6 +83,7 @@ struct xenon_priv {
> unsigned char bus_width;
> unsigned char timing;
> unsigned int clock;
> + struct clk *axi_clk;
>
> int phy_type;
> /*
> --
> 2.14.1
>
More information about the linux-arm-kernel
mailing list