scsi: ufs: make the UFS variant a platform device

This change turns the UFS variant (SCSI_UFS_QCOM) into a UFS
a platform device.
In order to do so a few additional changes are required:
1. The ufshcd-pltfrm is no longer serves as a platform device.
Now it only serves as a group of platform APIs such as PM APIs
(runtime suspend/resume, system suspend/resume etc), parsers of
clocks, regulators and pm_levels from DT.
2. What used to be the old platform "probe" is now "only"
a pltfrm_init() routine, that does exactly the same, but only
being called by the new probe function of the UFS variant.

Reviewed-by: Rob Herring <[e-mail]>
Reviewed-by: Gilad Broner <[e-mail]>
Signed-off-by: Yaniv Gardi <[e-mail]>
Tested-by: Alim Akhtar <[e-mail]>
Reviewed-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

Documentation/devicetree/bindings/ufs/ufs-qcom.txt

···
+* Qualcomm Technologies Inc Universal Flash Storage (UFS) PHY
+
+UFSPHY nodes are defined to describe on-chip UFS PHY hardware macro.
+Each UFS PHY node should have its own node.
+
+To bind UFS PHY with UFS host controller, the controller node should
+contain a phandle reference to UFS PHY node.
+
+Required properties:
+- compatible        : compatible list, contains "qcom,ufs-phy-qmp-20nm"
+		      or "qcom,ufs-phy-qmp-14nm" according to the relevant phy in use.
+- reg               : should contain PHY register address space (mandatory),
+- reg-names         : indicates various resources passed to driver (via reg proptery) by name.
+                      Required "reg-names" is "phy_mem".
+- #phy-cells        : This property shall be set to 0
+- vdda-phy-supply   : phandle to main PHY supply for analog domain
+- vdda-pll-supply   : phandle to PHY PLL and Power-Gen block power supply
+- clocks	    : List of phandle and clock specifier pairs
+- clock-names       : List of clock input name strings sorted in the same
+		      order as the clocks property. "ref_clk_src", "ref_clk",
+		      "tx_iface_clk" & "rx_iface_clk" are mandatory but
+		      "ref_clk_parent" is optional
+
+Optional properties:
+- vdda-phy-max-microamp : specifies max. load that can be drawn from phy supply
+- vdda-pll-max-microamp : specifies max. load that can be drawn from pll supply
+- vddp-ref-clk-supply   : phandle to UFS device ref_clk pad power supply
+- vddp-ref-clk-max-microamp : specifies max. load that can be drawn from this supply
+- vddp-ref-clk-always-on : specifies if this supply needs to be kept always on
+
+Example:
+
+	ufsphy1: ufsphy@0xfc597000 {
+		compatible = "qcom,ufs-phy-qmp-20nm";
+		reg = <0xfc597000 0x800>;
+		reg-names = "phy_mem";
+		#phy-cells = <0>;
+		vdda-phy-supply = <&pma8084_l4>;
+		vdda-pll-supply = <&pma8084_l12>;
+		vdda-phy-max-microamp = <50000>;
+		vdda-pll-max-microamp = <1000>;
+		clock-names = "ref_clk_src",
+			"ref_clk_parent",
+			"ref_clk",
+			"tx_iface_clk",
+			"rx_iface_clk";
+		clocks = <&clock_rpm clk_ln_bb_clk>,
+			<&clock_gcc clk_pcie_1_phy_ldo >,
+			<&clock_gcc clk_ufs_phy_ldo>,
+			<&clock_gcc clk_gcc_ufs_tx_cfg_clk>,
+			<&clock_gcc clk_gcc_ufs_rx_cfg_clk>;
+	};
+
+	ufshc@0xfc598000 {
+		...
+		phys = <&ufsphy1>;
+		phy-names = "ufsphy";
+	};

Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt

···
 Each UFS controller instance should have its own node.
 
 Required properties:
-- compatible        : compatible list, contains "jedec,ufs-1.1"
+- compatible		: must contain "jedec,ufs-1.1", may also list one or more
+					  of the following:
+					  "qcom,msm8994-ufshc"
+					  "qcom,msm8996-ufshc"
+					  "qcom,ufshc"
 - interrupts        : <interrupt mapping for UFS host controller IRQ>
 - reg               : <registers mapping>
 
 Optional properties:
+- phys                  : phandle to UFS PHY node
+- phy-names             : the string "ufsphy" when is found in a node, along
+                          with "phys" attribute, provides phandle to UFS PHY node
 - vdd-hba-supply        : phandle to UFS host controller supply regulator node
 - vcc-supply            : phandle to VCC supply regulator node
 - vccq-supply           : phandle to VCCQ supply regulator node
···
 		clocks = <&core 0>, <&ref 0>, <&iface 0>;
 		clock-names = "core_clk", "ref_clk", "iface_clk";
 		freq-table-hz = <100000000 200000000>, <0 0>, <0 0>;
+		phys = <&ufsphy1>;
+		phy-names = "ufsphy";
 	};

drivers/scsi/ufs/ufs-qcom.c

···
 
 #include <linux/phy/phy-qcom-ufs.h>
 #include "ufshcd.h"
+#include "ufshcd-pltfrm.h"
 #include "unipro.h"
 #include "ufs-qcom.h"
 #include "ufshci.h"
···
  * The variant operations configure the necessary controller and PHY
  * handshake during initialization.
  */
-static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
+static struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.name                   = "qcom",
 	.init                   = ufs_qcom_init,
 	.exit                   = ufs_qcom_exit,
···
 	.suspend		= ufs_qcom_suspend,
 	.resume			= ufs_qcom_resume,
 };
+
+/**
+ * ufs_qcom_probe - probe routine of the driver
+ * @pdev: pointer to Platform device handle
+ *
+ * Return zero for success and non-zero for failure
+ */
+static int ufs_qcom_probe(struct platform_device *pdev)
+{
+	int err;
+	struct device *dev = &pdev->dev;
+
+	/* Perform generic probe */
+	err = ufshcd_pltfrm_init(pdev, &ufs_hba_qcom_vops);
+	if (err)
+		dev_err(dev, "ufshcd_pltfrm_init() failed %d\n", err);
+
+	return err;
+}
+
+/**
+ * ufs_qcom_remove - set driver_data of the device to NULL
+ * @pdev: pointer to platform device handle
+ *
+ * Always return 0
+ */
+static int ufs_qcom_remove(struct platform_device *pdev)
+{
+	struct ufs_hba *hba =  platform_get_drvdata(pdev);
+
+	pm_runtime_get_sync(&(pdev)->dev);
+	ufshcd_remove(hba);
+	return 0;
+}
+
+static const struct of_device_id ufs_qcom_of_match[] = {
+	{ .compatible = "qcom,ufshc"},
+	{},
+};
+
+static const struct dev_pm_ops ufs_qcom_pm_ops = {
+	.suspend	= ufshcd_pltfrm_suspend,
+	.resume		= ufshcd_pltfrm_resume,
+	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
+	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
+	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
+};
+
+static struct platform_driver ufs_qcom_pltform = {
+	.probe	= ufs_qcom_probe,
+	.remove	= ufs_qcom_remove,
+	.shutdown = ufshcd_pltfrm_shutdown,
+	.driver	= {
+		.name	= "ufshcd-qcom",
+		.pm	= &ufs_qcom_pm_ops,
+		.of_match_table = of_match_ptr(ufs_qcom_of_match),
+	},
+};
+module_platform_driver(ufs_qcom_pltform);
 
 MODULE_LICENSE("GPL v2");

drivers/scsi/ufs/ufshcd-pltfrm.c

···
 #include <linux/of.h>
 
 #include "ufshcd.h"
-
-static const struct of_device_id ufs_of_match[];
-static struct ufs_hba_variant_ops *get_variant_ops(struct device *dev)
-{
-	if (dev->of_node) {
-		const struct of_device_id *match;
-
-		match = of_match_node(ufs_of_match, dev->of_node);
-		if (match)
-			return (struct ufs_hba_variant_ops *)match->data;
-	}
-
-	return NULL;
-}
+#include "ufshcd-pltfrm.h"
 
 static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 {
···
  * Returns 0 if successful
  * Returns non-zero otherwise
  */
-static int ufshcd_pltfrm_suspend(struct device *dev)
+int ufshcd_pltfrm_suspend(struct device *dev)
 {
 	return ufshcd_system_suspend(dev_get_drvdata(dev));
 }
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_suspend);
 
 /**
  * ufshcd_pltfrm_resume - resume power management function
···
  * Returns 0 if successful
  * Returns non-zero otherwise
  */
-static int ufshcd_pltfrm_resume(struct device *dev)
+int ufshcd_pltfrm_resume(struct device *dev)
 {
 	return ufshcd_system_resume(dev_get_drvdata(dev));
 }
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_resume);
 
-static int ufshcd_pltfrm_runtime_suspend(struct device *dev)
+int ufshcd_pltfrm_runtime_suspend(struct device *dev)
 {
 	return ufshcd_runtime_suspend(dev_get_drvdata(dev));
 }
-static int ufshcd_pltfrm_runtime_resume(struct device *dev)
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_runtime_suspend);
+
+int ufshcd_pltfrm_runtime_resume(struct device *dev)
 {
 	return ufshcd_runtime_resume(dev_get_drvdata(dev));
 }
-static int ufshcd_pltfrm_runtime_idle(struct device *dev)
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_runtime_resume);
+
+int ufshcd_pltfrm_runtime_idle(struct device *dev)
 {
 	return ufshcd_runtime_idle(dev_get_drvdata(dev));
 }
-#else /* !CONFIG_PM */
-#define ufshcd_pltfrm_suspend	NULL
-#define ufshcd_pltfrm_resume	NULL
-#define ufshcd_pltfrm_runtime_suspend	NULL
-#define ufshcd_pltfrm_runtime_resume	NULL
-#define ufshcd_pltfrm_runtime_idle	NULL
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_runtime_idle);
+
 #endif /* CONFIG_PM */
 
-static void ufshcd_pltfrm_shutdown(struct platform_device *pdev)
+void ufshcd_pltfrm_shutdown(struct platform_device *pdev)
 {
 	ufshcd_shutdown((struct ufs_hba *)platform_get_drvdata(pdev));
 }
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_shutdown);
 
 /**
- * ufshcd_pltfrm_probe - probe routine of the driver
+ * ufshcd_pltfrm_init - probe routine of the driver
  * @pdev: pointer to Platform device handle
+ * @vops: pointer to variant ops
  *
  * Returns 0 on success, non-zero value on failure
  */
-static int ufshcd_pltfrm_probe(struct platform_device *pdev)
+int ufshcd_pltfrm_init(struct platform_device *pdev,
+		       struct ufs_hba_variant_ops *vops)
 {
 	struct ufs_hba *hba;
 	void __iomem *mmio_base;
···
 		goto out;
 	}
 
-	hba->vops = get_variant_ops(&pdev->dev);
+	hba->vops = vops;
 
 	err = ufshcd_parse_clock_info(hba);
 	if (err) {
 		dev_err(&pdev->dev, "%s: clock parse failed %d\n",
 				__func__, err);
-		goto out;
+		goto dealloc_host;
 	}
 	err = ufshcd_parse_regulator_info(hba);
 	if (err) {
 		dev_err(&pdev->dev, "%s: regulator init failed %d\n",
 				__func__, err);
-		goto out;
+		goto dealloc_host;
 	}
 
 	pm_runtime_set_active(&pdev->dev);
···
 out_disable_rpm:
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
+dealloc_host:
+	ufshcd_dealloc_host(hba);
 out:
 	return err;
 }
-
-/**
- * ufshcd_pltfrm_remove - remove platform driver routine
- * @pdev: pointer to platform device handle
- *
- * Returns 0 on success, non-zero value on failure
- */
-static int ufshcd_pltfrm_remove(struct platform_device *pdev)
-{
-	struct ufs_hba *hba =  platform_get_drvdata(pdev);
-
-	pm_runtime_get_sync(&(pdev)->dev);
-	ufshcd_remove(hba);
-	return 0;
-}
-
-static const struct of_device_id ufs_of_match[] = {
-	{ .compatible = "jedec,ufs-1.1"},
-	{},
-};
-
-static const struct dev_pm_ops ufshcd_dev_pm_ops = {
-	.suspend	= ufshcd_pltfrm_suspend,
-	.resume		= ufshcd_pltfrm_resume,
-	.runtime_suspend = ufshcd_pltfrm_runtime_suspend,
-	.runtime_resume  = ufshcd_pltfrm_runtime_resume,
-	.runtime_idle    = ufshcd_pltfrm_runtime_idle,
-};
-
-static struct platform_driver ufshcd_pltfrm_driver = {
-	.probe	= ufshcd_pltfrm_probe,
-	.remove	= ufshcd_pltfrm_remove,
-	.shutdown = ufshcd_pltfrm_shutdown,
-	.driver	= {
-		.name	= "ufshcd",
-		.pm	= &ufshcd_dev_pm_ops,
-		.of_match_table = ufs_of_match,
-	},
-};
-
-module_platform_driver(ufshcd_pltfrm_driver);
+EXPORT_SYMBOL_GPL(ufshcd_pltfrm_init);
 
 MODULE_AUTHOR("Santosh Yaragnavi <[e-mail]>");
 MODULE_AUTHOR("Vinayak Holikatti <[e-mail]>");

drivers/scsi/ufs/ufshcd-pltfrm.h

···
+/* Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef UFSHCD_PLTFRM_H_
+#define UFSHCD_PLTFRM_H_
+
+#include "ufshcd.h"
+
+int ufshcd_pltfrm_init(struct platform_device *pdev,
+		       struct ufs_hba_variant_ops *vops);
+void ufshcd_pltfrm_shutdown(struct platform_device *pdev);
+
+#ifdef CONFIG_PM
+
+int ufshcd_pltfrm_suspend(struct device *dev);
+int ufshcd_pltfrm_resume(struct device *dev);
+int ufshcd_pltfrm_runtime_suspend(struct device *dev);
+int ufshcd_pltfrm_runtime_resume(struct device *dev);
+int ufshcd_pltfrm_runtime_idle(struct device *dev);
+
+#else /* !CONFIG_PM */
+
+#define ufshcd_pltfrm_suspend	NULL
+#define ufshcd_pltfrm_resume	NULL
+#define ufshcd_pltfrm_runtime_suspend	NULL
+#define ufshcd_pltfrm_runtime_resume	NULL
+#define ufshcd_pltfrm_runtime_idle	NULL
+
+#endif /* CONFIG_PM */
+
+#endif /* UFSHCD_PLTFRM_H_ */

drivers/scsi/ufs/ufshcd.c

···
 EXPORT_SYMBOL_GPL(ufshcd_remove);
 
 /**
+ * ufshcd_dealloc_host - deallocate Host Bus Adapter (HBA)
+ * @hba: pointer to Host Bus Adapter (HBA)
+ */
+void ufshcd_dealloc_host(struct ufs_hba *hba)
+{
+	scsi_host_put(hba->host);
+}
+EXPORT_SYMBOL_GPL(ufshcd_dealloc_host);
+
+/**
  * ufshcd_set_dma_mask - Set dma mask based on the controller
  *			 addressing capability
  * @hba: per adapter instance

drivers/scsi/ufs/ufshcd.h

···
 }
 
 int ufshcd_alloc_host(struct device *, struct ufs_hba **);
+void ufshcd_dealloc_host(struct ufs_hba *);
 int ufshcd_init(struct ufs_hba * , void __iomem * , unsigned int);
 void ufshcd_remove(struct ufs_hba *);