From bb16ea1742c8f35a9349b7508dc45d3a922db5f5 Mon Sep 17 00:00:00 2001
From: Gregory CLEMENT <gregory.clement@free-electrons.com>
Date: Mon, 2 Oct 2017 16:58:52 +0200
Subject: [PATCH] mmc: sdhci-xenon: Fix clock resource by adding an optional bus clock
Git-commit: bb16ea1742c8f35a9349b7508dc45d3a922db5f5
Patch-mainline: v4.14-rc4
References: bsc#1051510

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>
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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 Documentation/devicetree/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(-)

--- 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>;
 	};
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -490,9 +490,20 @@ static int xenon_probe(struct platform_d
 	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_d
 	/* 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_d
 
 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_
 {
 	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);
--- 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;
 	/*