[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

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@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
Hi Ulf and Adrian,

This patch should be merged in 4.14-rc, as it fixes real issues.

This patch maye 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 Sov and with more exhaustive testes that we found this
issue and the fix for it.

Thanks,

Gregory


 .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
 drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
 drivers/mmc/host/sdhci-xenon.h                     |  1 +
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
index b878a1e305af..6f3db1f809ab 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..845575593b59 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);
+		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
+		priv->axi_clk = NULL;
+	} 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 +540,9 @@ 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:
+	if (priv->axi_clk)
+		clk_disable_unprepare(priv->axi_clk);
 err_clk:
 	clk_disable_unprepare(pltfm_host->clk);
 free_pltfm:
@@ -538,6 +554,7 @@ 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);
@@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
 	sdhci_remove_host(host, 0);
 
 	xenon_sdhc_unprepare(host);
+	if (priv->axi_clk)
+		clk_disable_unprepare(priv->axi_clk);
 
 	clk_disable_unprepare(pltfm_host->clk);
 
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

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

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@vger.kernel.org>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
Hi Ulf and Adrian,

This patch should be merged in 4.14-rc, as it fixes real issues.

This patch maye 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 Sov and with more exhaustive testes that we found this
issue and the fix for it.

Thanks,

Gregory


 .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
 drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
 drivers/mmc/host/sdhci-xenon.h                     |  1 +
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
index b878a1e305af..6f3db1f809ab 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..845575593b59 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);
+		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
+		priv->axi_clk = NULL;
+	} 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 +540,9 @@ 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:
+	if (priv->axi_clk)
+		clk_disable_unprepare(priv->axi_clk);
 err_clk:
 	clk_disable_unprepare(pltfm_host->clk);
 free_pltfm:
@@ -538,6 +554,7 @@ 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);
@@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
 	sdhci_remove_host(host, 0);
 
 	xenon_sdhc_unprepare(host);
+	if (priv->axi_clk)
+		clk_disable_unprepare(priv->axi_clk);
 
 	clk_disable_unprepare(pltfm_host->clk);
 
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

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi,
 
 On jeu., sept. 28 2017, Gregory CLEMENT <gregory.clement@free-electrons.com> wrote:

> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> index 2eec2e652c53..845575593b59 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);
> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);

I should manage the -EPROBE_DEFER case here. So a v2 of this patch is
coming soon.

Sorry to not have seen this before sending the patch.

Gregory

> +		priv->axi_clk = NULL;
> +	} 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 +540,9 @@ 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:
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>  	sdhci_remove_host(host, 0);
>  
>  	xenon_sdhc_unprepare(host);
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);
>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  
> 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
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi,
 
 On jeu., sept. 28 2017, Gregory CLEMENT <gregory.clement@free-electrons.com> wrote:

> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> index 2eec2e652c53..845575593b59 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);
> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);

I should manage the -EPROBE_DEFER case here. So a v2 of this patch is
coming soon.

Sorry to not have seen this before sending the patch.

Gregory

> +		priv->axi_clk = NULL;
> +	} 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 +540,9 @@ 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:
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>  	sdhci_remove_host(host, 0);
>  
>  	xenon_sdhc_unprepare(host);
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);
>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  
> 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
>

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

+ DT maintainers

On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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@vger.kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> Hi Ulf and Adrian,
> 
> This patch should be merged in 4.14-rc, as it fixes real issues.
> 
> This patch maye 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 Sov and with more exhaustive testes that we found this
> issue and the fix for it.
> 
> Thanks,
> 
> Gregory
> 
> 
>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>  3 files changed, 30 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..6f3db1f809ab 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".

Is "bus" more suitable?

>  
>  - 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..845575593b59 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);
> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);

Since the bus clock is optional, can we remove this err msg?

> +		priv->axi_clk = NULL;
> +	} 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 +540,9 @@ 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:
> +	if (priv->axi_clk)

clk_disable_unprepare() will do the check. So this check could be removed
to simplify the err path

> +		clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>  	sdhci_remove_host(host, 0);
>  
>  	xenon_sdhc_unprepare(host);
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);

ditto

>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  
> 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;
>  	/*

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

+ DT maintainers

On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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@vger.kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> Hi Ulf and Adrian,
> 
> This patch should be merged in 4.14-rc, as it fixes real issues.
> 
> This patch maye 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 Sov and with more exhaustive testes that we found this
> issue and the fix for it.
> 
> Thanks,
> 
> Gregory
> 
> 
>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>  3 files changed, 30 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..6f3db1f809ab 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".

Is "bus" more suitable?

>  
>  - 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..845575593b59 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);
> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);

Since the bus clock is optional, can we remove this err msg?

> +		priv->axi_clk = NULL;
> +	} 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 +540,9 @@ 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:
> +	if (priv->axi_clk)

clk_disable_unprepare() will do the check. So this check could be removed
to simplify the err path

> +		clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>  	sdhci_remove_host(host, 0);
>  
>  	xenon_sdhc_unprepare(host);
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);

ditto

>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  
> 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;
>  	/*

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

+ DT maintainers

On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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@vger.kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> Hi Ulf and Adrian,
> 
> This patch should be merged in 4.14-rc, as it fixes real issues.
> 
> This patch maye 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 Sov and with more exhaustive testes that we found this
> issue and the fix for it.
> 
> Thanks,
> 
> Gregory
> 
> 
>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>  3 files changed, 30 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..6f3db1f809ab 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".

Is "bus" more suitable?

>  
>  - 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..845575593b59 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);
> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);

Since the bus clock is optional, can we remove this err msg?

> +		priv->axi_clk = NULL;
> +	} 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 +540,9 @@ 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:
> +	if (priv->axi_clk)

clk_disable_unprepare() will do the check. So this check could be removed
to simplify the err path

> +		clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>  	sdhci_remove_host(host, 0);
>  
>  	xenon_sdhc_unprepare(host);
> +	if (priv->axi_clk)
> +		clk_disable_unprepare(priv->axi_clk);

ditto

>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  
> 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;
>  	/*

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Jisheng,
 
 On ven., sept. 29 2017, Jisheng Zhang <Jisheng.Zhang-Gq53QDLGkWKakBO8gow8eQ@public.gmane.org> wrote:

> + DT maintainers
>
> On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>> Signed-off-by: Gregory CLEMENT <gregory.clement-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
>> ---
>> Hi Ulf and Adrian,
>> 
>> This patch should be merged in 4.14-rc, as it fixes real issues.
>> 
>> This patch maye 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 Sov and with more exhaustive testes that we found this
>> issue and the fix for it.
>> 
>> Thanks,
>> 
>> Gregory
>> 
>> 
>>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>>  3 files changed, 30 insertions(+), 8 deletions(-)
>> 
>> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
>> index b878a1e305af..6f3db1f809ab 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".
>
> Is "bus" more suitable?

I find bus too vague.

>
>>  
>>  - 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..845575593b59 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);
>> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
>
> Since the bus clock is optional, can we remove this err msg?

I will change it in dev_info.

>
>> +		priv->axi_clk = NULL;
>> +	} 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 +540,9 @@ 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:
>> +	if (priv->axi_clk)
>
> clk_disable_unprepare() will do the check. So this check could be removed
> to simplify the err path

Right I removed it


>
>> +		clk_disable_unprepare(priv->axi_clk);
>>  err_clk:
>>  	clk_disable_unprepare(pltfm_host->clk);
>>  free_pltfm:
>> @@ -538,6 +554,7 @@ 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);
>> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>>  	sdhci_remove_host(host, 0);
>>  
>>  	xenon_sdhc_unprepare(host);
>> +	if (priv->axi_clk)
>> +		clk_disable_unprepare(priv->axi_clk);
>
> ditto

OK

Thanks,

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Jisheng,
 
 On ven., sept. 29 2017, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:

> + DT maintainers
>
> On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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@vger.kernel.org>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
>> ---
>> Hi Ulf and Adrian,
>> 
>> This patch should be merged in 4.14-rc, as it fixes real issues.
>> 
>> This patch maye 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 Sov and with more exhaustive testes that we found this
>> issue and the fix for it.
>> 
>> Thanks,
>> 
>> Gregory
>> 
>> 
>>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>>  3 files changed, 30 insertions(+), 8 deletions(-)
>> 
>> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
>> index b878a1e305af..6f3db1f809ab 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".
>
> Is "bus" more suitable?

I find bus too vague.

>
>>  
>>  - 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..845575593b59 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);
>> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
>
> Since the bus clock is optional, can we remove this err msg?

I will change it in dev_info.

>
>> +		priv->axi_clk = NULL;
>> +	} 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 +540,9 @@ 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:
>> +	if (priv->axi_clk)
>
> clk_disable_unprepare() will do the check. So this check could be removed
> to simplify the err path

Right I removed it


>
>> +		clk_disable_unprepare(priv->axi_clk);
>>  err_clk:
>>  	clk_disable_unprepare(pltfm_host->clk);
>>  free_pltfm:
>> @@ -538,6 +554,7 @@ 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);
>> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>>  	sdhci_remove_host(host, 0);
>>  
>>  	xenon_sdhc_unprepare(host);
>> +	if (priv->axi_clk)
>> +		clk_disable_unprepare(priv->axi_clk);
>
> ditto

OK

Thanks,

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Jisheng,
 
 On ven., sept. 29 2017, Jisheng Zhang <Jisheng.Zhang@synaptics.com> wrote:

> + DT maintainers
>
> On Thu, 28 Sep 2017 17:05:20 +0200 Gregory CLEMENT 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@vger.kernel.org>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
>> ---
>> Hi Ulf and Adrian,
>> 
>> This patch should be merged in 4.14-rc, as it fixes real issues.
>> 
>> This patch maye 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 Sov and with more exhaustive testes that we found this
>> issue and the fix for it.
>> 
>> Thanks,
>> 
>> Gregory
>> 
>> 
>>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>>  3 files changed, 30 insertions(+), 8 deletions(-)
>> 
>> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
>> index b878a1e305af..6f3db1f809ab 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".
>
> Is "bus" more suitable?

I find bus too vague.

>
>>  
>>  - 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..845575593b59 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);
>> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
>
> Since the bus clock is optional, can we remove this err msg?

I will change it in dev_info.

>
>> +		priv->axi_clk = NULL;
>> +	} 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 +540,9 @@ 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:
>> +	if (priv->axi_clk)
>
> clk_disable_unprepare() will do the check. So this check could be removed
> to simplify the err path

Right I removed it


>
>> +		clk_disable_unprepare(priv->axi_clk);
>>  err_clk:
>>  	clk_disable_unprepare(pltfm_host->clk);
>>  free_pltfm:
>> @@ -538,6 +554,7 @@ 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);
>> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>>  	sdhci_remove_host(host, 0);
>>  
>>  	xenon_sdhc_unprepare(host);
>> +	if (priv->axi_clk)
>> +		clk_disable_unprepare(priv->axi_clk);
>
> ditto

OK

Thanks,

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Thomas Petazzoni]

Hello,

On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:

> >>  - 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".  
> >
> > Is "bus" more suitable?  
> 
> I find bus too vague.

Actually no, I believe "bus" is more common. Indeed, you could have the
same IP, attached to a different interconnect I guess.

> >>  	/*
> >>  	 * 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)) {

-EPROBE_DEFER handling ?

> >> +		err = PTR_ERR(priv->axi_clk);
> >> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);  
> >
> > Since the bus clock is optional, can we remove this err msg?  
> 
> I will change it in dev_info.

This clock is optional (in order to keep DT backward compatibility), so
there shouldn't be any error message, be it dev_err() or dev_info().

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Thomas Petazzoni]

Hello,

On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:

> >>  - 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".  
> >
> > Is "bus" more suitable?  
> 
> I find bus too vague.

Actually no, I believe "bus" is more common. Indeed, you could have the
same IP, attached to a different interconnect I guess.

> >>  	/*
> >>  	 * 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)) {

-EPROBE_DEFER handling ?

> >> +		err = PTR_ERR(priv->axi_clk);
> >> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);  
> >
> > Since the bus clock is optional, can we remove this err msg?  
> 
> I will change it in dev_info.

This clock is optional (in order to keep DT backward compatibility), so
there shouldn't be any error message, be it dev_err() or dev_info().

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Thomas Petazzoni]

Hello,

On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:

> >>  - 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".  
> >
> > Is "bus" more suitable?  
> 
> I find bus too vague.

Actually no, I believe "bus" is more common. Indeed, you could have the
same IP, attached to a different interconnect I guess.

> >>  	/*
> >>  	 * 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)) {

-EPROBE_DEFER handling ?

> >> +		err = PTR_ERR(priv->axi_clk);
> >> +		dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);  
> >
> > Since the bus clock is optional, can we remove this err msg?  
> 
> I will change it in dev_info.

This clock is optional (in order to keep DT backward compatibility), so
there shouldn't be any error message, be it dev_err() or dev_info().

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Thomas,
 
 On ven., sept. 29 2017, Thomas Petazzoni <thomas.petazzoni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> wrote:

> Hello,
>
> On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:
>
>> >>  - 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".  
>> >
>> > Is "bus" more suitable?  
>> 
>> I find bus too vague.
>
> Actually no, I believe "bus" is more common. Indeed, you could have the
> same IP, attached to a different interconnect I guess.
>
>> >>  	/*
>> >>  	 * 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)) {
>
> -EPROBE_DEFER handling ?


See
http://lists.infradead.org/pipermail/linux-arm-kernel/2017-September/533510.html

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Thomas,
 
 On ven., sept. 29 2017, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:

> Hello,
>
> On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:
>
>> >>  - 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".  
>> >
>> > Is "bus" more suitable?  
>> 
>> I find bus too vague.
>
> Actually no, I believe "bus" is more common. Indeed, you could have the
> same IP, attached to a different interconnect I guess.
>
>> >>  	/*
>> >>  	 * 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)) {
>
> -EPROBE_DEFER handling ?


See
http://lists.infradead.org/pipermail/linux-arm-kernel/2017-September/533510.html

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

Hi Thomas,
 
 On ven., sept. 29 2017, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:

> Hello,
>
> On Fri, 29 Sep 2017 11:13:00 +0200, Gregory CLEMENT wrote:
>
>> >>  - 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".  
>> >
>> > Is "bus" more suitable?  
>> 
>> I find bus too vague.
>
> Actually no, I believe "bus" is more common. Indeed, you could have the
> same IP, attached to a different interconnect I guess.
>
>> >>  	/*
>> >>  	 * 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)) {
>
> -EPROBE_DEFER handling ?


See
http://lists.infradead.org/pipermail/linux-arm-kernel/2017-September/533510.html

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Ziji Hu]

Hi Gregory,

2017-09-28 23:05 GMT+08:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> 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@vger.kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> Hi Ulf and Adrian,
>
> This patch should be merged in 4.14-rc, as it fixes real issues.
>
> This patch maye 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 Sov and with more exhaustive testes that we found this
> issue and the fix for it.

    I know very little about clk in Linux.
    But I just happened to review this very issue before I left Marvell.
    I had some concerns about this patch at that time.
    Please check the following.

    1. If that network device is used again, so that clock will be setup *twice*
    since there are two duplicated clock setup in that network driver
and Xenon driver. Right?
    2. If that network device is used again and Xenon later exists and
shutdown the clock,
    will that network device be corrupted?
    3. In my very own opinion, such a shared AXI bus clock might be
controlled in u-boot or
    a "SoC-level" init routine.

    Please correct me if there is any misunderstanding.

    Thank you.

Best regards,
Hu Ziji

>
> Thanks,
>
> Gregory
>
>
>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>  3 files changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..6f3db1f809ab 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..845575593b59 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);
> +               dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
> +               priv->axi_clk = NULL;
> +       } 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 +540,9 @@ 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:
> +       if (priv->axi_clk)
> +               clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>         clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>         sdhci_remove_host(host, 0);
>
>         xenon_sdhc_unprepare(host);
> +       if (priv->axi_clk)
> +               clk_disable_unprepare(priv->axi_clk);
>
>         clk_disable_unprepare(pltfm_host->clk);
>
> 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Ziji Hu]

Hi Gregory,

2017-09-28 23:05 GMT+08:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> 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@vger.kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> ---
> Hi Ulf and Adrian,
>
> This patch should be merged in 4.14-rc, as it fixes real issues.
>
> This patch maye 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 Sov and with more exhaustive testes that we found this
> issue and the fix for it.

    I know very little about clk in Linux.
    But I just happened to review this very issue before I left Marvell.
    I had some concerns about this patch at that time.
    Please check the following.

    1. If that network device is used again, so that clock will be setup *twice*
    since there are two duplicated clock setup in that network driver
and Xenon driver. Right?
    2. If that network device is used again and Xenon later exists and
shutdown the clock,
    will that network device be corrupted?
    3. In my very own opinion, such a shared AXI bus clock might be
controlled in u-boot or
    a "SoC-level" init routine.

    Please correct me if there is any misunderstanding.

    Thank you.

Best regards,
Hu Ziji

>
> Thanks,
>
> Gregory
>
>
>  .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 ++++++-----
>  drivers/mmc/host/sdhci-xenon.c                     | 25 +++++++++++++++++++---
>  drivers/mmc/host/sdhci-xenon.h                     |  1 +
>  3 files changed, 30 insertions(+), 8 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt b/Documentation/devicetree/bindings/mmc/marvell,xenon-sdhci.txt
> index b878a1e305af..6f3db1f809ab 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..845575593b59 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);
> +               dev_err(&pdev->dev, "Failed to setup axi clk: %d\n", err);
> +               priv->axi_clk = NULL;
> +       } 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 +540,9 @@ 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:
> +       if (priv->axi_clk)
> +               clk_disable_unprepare(priv->axi_clk);
>  err_clk:
>         clk_disable_unprepare(pltfm_host->clk);
>  free_pltfm:
> @@ -538,6 +554,7 @@ 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);
> @@ -546,6 +563,8 @@ static int xenon_remove(struct platform_device *pdev)
>         sdhci_remove_host(host, 0);
>
>         xenon_sdhc_unprepare(host);
> +       if (priv->axi_clk)
> +               clk_disable_unprepare(priv->axi_clk);
>
>         clk_disable_unprepare(pltfm_host->clk);
>
> 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

Hi Ziji,

On Sat, 30 Sep 2017 10:47:39 +0800 Ziji Hu wrote:

> Hi Gregory,
> 
> 2017-09-28 23:05 GMT+08:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> > 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@vger.kernel.org>
> > Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> > ---
> > Hi Ulf and Adrian,
> >
> > This patch should be merged in 4.14-rc, as it fixes real issues.
> >
> > This patch maye 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 Sov and with more exhaustive testes that we found this
> > issue and the fix for it.  
> 
>     I know very little about clk in Linux.
>     But I just happened to review this very issue before I left Marvell.
>     I had some concerns about this patch at that time.
>     Please check the following.
> 
>     1. If that network device is used again, so that clock will be setup *twice*
>     since there are two duplicated clock setup in that network driver
> and Xenon driver. Right?

The first "setup" will be executed, the second one just increase the enable
and prepare count.

>     2. If that network device is used again and Xenon later exists and
> shutdown the clock,
>     will that network device be corrupted?

No. The enable and prepare count is reduced to 1, nothing else could happen.
The clock won't be shutdown until there's no users.

>     3. In my very own opinion, such a shared AXI bus clock might be
> controlled in u-boot or
>     a "SoC-level" init routine.

IMHO, it's the driver's responsibility to manage its own clocks.

Thanks

Re: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

Hi Ziji,

On Sat, 30 Sep 2017 10:47:39 +0800 Ziji Hu wrote:

> Hi Gregory,
> 
> 2017-09-28 23:05 GMT+08:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> > 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@vger.kernel.org>
> > Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> > ---
> > Hi Ulf and Adrian,
> >
> > This patch should be merged in 4.14-rc, as it fixes real issues.
> >
> > This patch maye 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 Sov and with more exhaustive testes that we found this
> > issue and the fix for it.  
> 
>     I know very little about clk in Linux.
>     But I just happened to review this very issue before I left Marvell.
>     I had some concerns about this patch at that time.
>     Please check the following.
> 
>     1. If that network device is used again, so that clock will be setup *twice*
>     since there are two duplicated clock setup in that network driver
> and Xenon driver. Right?

The first "setup" will be executed, the second one just increase the enable
and prepare count.

>     2. If that network device is used again and Xenon later exists and
> shutdown the clock,
>     will that network device be corrupted?

No. The enable and prepare count is reduced to 1, nothing else could happen.
The clock won't be shutdown until there's no users.

>     3. In my very own opinion, such a shared AXI bus clock might be
> controlled in u-boot or
>     a "SoC-level" init routine.

IMHO, it's the driver's responsibility to manage its own clocks.

Thanks

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Jisheng Zhang]

Hi Ziji,

On Sat, 30 Sep 2017 10:47:39 +0800 Ziji Hu wrote:

> Hi Gregory,
> 
> 2017-09-28 23:05 GMT+08:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> > 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@vger.kernel.org>
> > Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
> > ---
> > Hi Ulf and Adrian,
> >
> > This patch should be merged in 4.14-rc, as it fixes real issues.
> >
> > This patch maye 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 Sov and with more exhaustive testes that we found this
> > issue and the fix for it.  
> 
>     I know very little about clk in Linux.
>     But I just happened to review this very issue before I left Marvell.
>     I had some concerns about this patch at that time.
>     Please check the following.
> 
>     1. If that network device is used again, so that clock will be setup *twice*
>     since there are two duplicated clock setup in that network driver
> and Xenon driver. Right?

The first "setup" will be executed, the second one just increase the enable
and prepare count.

>     2. If that network device is used again and Xenon later exists and
> shutdown the clock,
>     will that network device be corrupted?

No. The enable and prepare count is reduced to 1, nothing else could happen.
The clock won't be shutdown until there's no users.

>     3. In my very own opinion, such a shared AXI bus clock might be
> controlled in u-boot or
>     a "SoC-level" init routine.

IMHO, it's the driver's responsibility to manage its own clocks.

Thanks

[PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock

[Gregory CLEMENT]

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.

commit bb16ea1742c8f35a9349b7508dc45d3a922db5f5 upstream

Fixes: 3a3748dba881 ("mmc: sdhci-xenon: Add Marvell Xenon SDHC core
functionality)"
CC: Stable <stable@vger.kernel.org>
Tested-by: Zhoujie Wu <zjwu@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
 .../bindings/mmc/marvell,xenon-sdhci.txt           | 12 +++++++-----
 drivers/mmc/host/sdhci-xenon.c                     | 22 ++++++++++++++++++----
 drivers/mmc/host/sdhci-xenon.h                     |  1 +
 3 files changed, 26 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 c580af05b033..6af4d77d5bc3 100644
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -490,9 +490,20 @@ 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);
 
@@ -501,11 +512,11 @@ 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;
 
 	err = sdhci_add_host(host);
 	if (err)
@@ -515,6 +526,8 @@ static int xenon_probe(struct platform_device *pdev)
 
 remove_sdhc:
 	xenon_sdhc_unprepare(host);
+err_clk_axi:
+	clk_disable_unprepare(priv->axi_clk);
 err_clk:
 	clk_disable_unprepare(pltfm_host->clk);
 free_pltfm:
@@ -526,11 +539,12 @@ 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);
 
 	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 73debb42dc2f..0ab4c224dc84 100644
--- a/drivers/mmc/host/sdhci-xenon.h
+++ b/drivers/mmc/host/sdhci-xenon.h
@@ -82,6 +82,7 @@ struct xenon_priv {
 	unsigned char	bus_width;
 	unsigned char	timing;
 	unsigned int	clock;
+	struct clk      *axi_clk;
 
 	int		phy_type;
 	/*
-- 
2.14.2