[RFC][PATCH 1/7] USB: OHCI: make ohci-exynos a separate driver

[manjunath.goudar@linaro.org (Manjunath Goudar)]

Separate the  Samsung OHCI EXYNOS host controller driver from ohci-hcd
host code so that it can be built as a separate driver module.
This work is part of enabling multi-platform kernels on ARM.

Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Greg KH <greg@kroah.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb at vger.kernel.org
---
 drivers/usb/host/Kconfig       |    2 +-
 drivers/usb/host/Makefile      |    1 +
 drivers/usb/host/ohci-exynos.c |  154 +++++++++++++++++-----------------------
 drivers/usb/host/ohci-hcd.c    |   20 +-----
 4 files changed, 70 insertions(+), 107 deletions(-)

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 5391a38..f827386 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -484,7 +484,7 @@ config USB_OHCI_SH
 	  If you use the PCI OHCI controller, this option is not necessary.
 
 config USB_OHCI_EXYNOS
-	boolean "OHCI support for Samsung EXYNOS SoC Series"
+	tristate "OHCI support for Samsung EXYNOS SoC Series"
 	depends on ARCH_EXYNOS
 	help
 	 Enable support for the Samsung Exynos SOC's on-chip OHCI controller.
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index 8a89c3d..2a4f11f 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_USB_ISP1362_HCD)	+= isp1362-hcd.o
 obj-$(CONFIG_USB_OHCI_HCD)	+= ohci-hcd.o
 obj-$(CONFIG_USB_OHCI_HCD_PCI)	+= ohci-pci.o
 obj-$(CONFIG_USB_OHCI_HCD_PLATFORM)	+= ohci-platform.o
+obj-$(CONFIG_USB_OHCI_EXYNOS)	+= ohci-exynos.o
 
 obj-$(CONFIG_USB_UHCI_HCD)	+= uhci-hcd.o
 obj-$(CONFIG_USB_FHCI_HCD)	+= fhci.o
diff --git a/drivers/usb/host/ohci-exynos.c b/drivers/usb/host/ohci-exynos.c
index 07592c0..a5f4c33 100644
--- a/drivers/usb/host/ohci-exynos.c
+++ b/drivers/usb/host/ohci-exynos.c
@@ -12,24 +12,38 @@
  */
 
 #include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/usb-ohci-exynos.h>
 #include <linux/usb/phy.h>
 #include <linux/usb/samsung_usb_phy.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/otg.h>
+
+#include "ohci.h"
+
+#define DRIVER_DESC "OHCI exynos driver"
+
+static const char hcd_name[] = "ohci-exynos";
+static struct hc_driver __read_mostly exynos_ohci_hc_driver;
+
+#define to_exynos_ohci(hcd) (struct exynos_ohci_hcd *)(hcd_to_ohci(hcd)->priv)
 
 struct exynos_ohci_hcd {
-	struct device *dev;
-	struct usb_hcd *hcd;
 	struct clk *clk;
 	struct usb_phy *phy;
 	struct usb_otg *otg;
 	struct exynos4_ohci_platdata *pdata;
 };
 
-static void exynos_ohci_phy_enable(struct exynos_ohci_hcd *exynos_ohci)
+static void exynos_ohci_phy_enable(struct platform_device *pdev)
 {
-	struct platform_device *pdev = to_platform_device(exynos_ohci->dev);
+	struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
 
 	if (exynos_ohci->phy)
 		usb_phy_init(exynos_ohci->phy);
@@ -37,9 +51,9 @@ static void exynos_ohci_phy_enable(struct exynos_ohci_hcd *exynos_ohci)
 		exynos_ohci->pdata->phy_init(pdev, USB_PHY_TYPE_HOST);
 }
 
-static void exynos_ohci_phy_disable(struct exynos_ohci_hcd *exynos_ohci)
+static void exynos_ohci_phy_disable(struct platform_device *pdev)
 {
-	struct platform_device *pdev = to_platform_device(exynos_ohci->dev);
+	struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
 
 	if (exynos_ohci->phy)
 		usb_phy_shutdown(exynos_ohci->phy);
@@ -47,57 +61,6 @@ static void exynos_ohci_phy_disable(struct exynos_ohci_hcd *exynos_ohci)
 		exynos_ohci->pdata->phy_exit(pdev, USB_PHY_TYPE_HOST);
 }
 
-static int ohci_exynos_reset(struct usb_hcd *hcd)
-{
-	return ohci_init(hcd_to_ohci(hcd));
-}
-
-static int ohci_exynos_start(struct usb_hcd *hcd)
-{
-	struct ohci_hcd *ohci = hcd_to_ohci(hcd);
-	int ret;
-
-	ohci_dbg(ohci, "ohci_exynos_start, ohci:%p", ohci);
-
-	ret = ohci_run(ohci);
-	if (ret < 0) {
-		dev_err(hcd->self.controller, "can't start %s\n",
-			hcd->self.bus_name);
-		ohci_stop(hcd);
-		return ret;
-	}
-
-	return 0;
-}
-
-static const struct hc_driver exynos_ohci_hc_driver = {
-	.description		= hcd_name,
-	.product_desc		= "EXYNOS OHCI Host Controller",
-	.hcd_priv_size		= sizeof(struct ohci_hcd),
-
-	.irq			= ohci_irq,
-	.flags			= HCD_MEMORY|HCD_USB11,
-
-	.reset			= ohci_exynos_reset,
-	.start			= ohci_exynos_start,
-	.stop			= ohci_stop,
-	.shutdown		= ohci_shutdown,
-
-	.get_frame_number	= ohci_get_frame,
-
-	.urb_enqueue		= ohci_urb_enqueue,
-	.urb_dequeue		= ohci_urb_dequeue,
-	.endpoint_disable	= ohci_endpoint_disable,
-
-	.hub_status_data	= ohci_hub_status_data,
-	.hub_control		= ohci_hub_control,
-#ifdef	CONFIG_PM
-	.bus_suspend		= ohci_bus_suspend,
-	.bus_resume		= ohci_bus_resume,
-#endif
-	.start_port_reset	= ohci_start_port_reset,
-};
-
 static u64 ohci_exynos_dma_mask = DMA_BIT_MASK(32);
 
 static int exynos_ohci_probe(struct platform_device *pdev)
@@ -105,7 +68,6 @@ static int exynos_ohci_probe(struct platform_device *pdev)
 	struct exynos4_ohci_platdata *pdata = pdev->dev.platform_data;
 	struct exynos_ohci_hcd *exynos_ohci;
 	struct usb_hcd *hcd;
-	struct ohci_hcd *ohci;
 	struct resource *res;
 	struct usb_phy *phy;
 	int irq;
@@ -121,15 +83,18 @@ static int exynos_ohci_probe(struct platform_device *pdev)
 	if (!pdev->dev.coherent_dma_mask)
 		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
 
-	exynos_ohci = devm_kzalloc(&pdev->dev, sizeof(struct exynos_ohci_hcd),
-					GFP_KERNEL);
-	if (!exynos_ohci)
+	hcd = usb_create_hcd(&exynos_ohci_hc_driver,
+				&pdev->dev, dev_name(&pdev->dev));
+	if (!hcd) {
+		dev_err(&pdev->dev, "Unable to create HCD\n");
 		return -ENOMEM;
 
 	if (of_device_is_compatible(pdev->dev.of_node,
 					"samsung,exynos5440-ohci"))
 		goto skip_phy;
 
+	}
+	exynos_ohci = to_exynos_ohci(hcd);
 	phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
 	if (IS_ERR(phy)) {
 		/* Fallback to pdata */
@@ -146,7 +111,6 @@ static int exynos_ohci_probe(struct platform_device *pdev)
 
 skip_phy:
 
-	exynos_ohci->dev = &pdev->dev;
 
 	hcd = usb_create_hcd(&exynos_ohci_hc_driver, &pdev->dev,
 					dev_name(&pdev->dev));
@@ -155,7 +119,6 @@ skip_phy:
 		return -ENOMEM;
 	}
 
-	exynos_ohci->hcd = hcd;
 	exynos_ohci->clk = devm_clk_get(&pdev->dev, "usbhost");
 
 	if (IS_ERR(exynos_ohci->clk)) {
@@ -192,13 +155,11 @@ skip_phy:
 	}
 
 	if (exynos_ohci->otg)
-		exynos_ohci->otg->set_host(exynos_ohci->otg,
-					&exynos_ohci->hcd->self);
+		exynos_ohci->otg->set_host(exynos_ohci->otg, &hcd->self);
 
-	exynos_ohci_phy_enable(exynos_ohci);
+	exynos_ohci_phy_enable(pdev);
 
-	ohci = hcd_to_ohci(hcd);
-	ohci_hcd_init(ohci);
+	ohci_setup(hcd);
 
 	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
 	if (err) {
@@ -206,12 +167,12 @@ skip_phy:
 		goto fail_add_hcd;
 	}
 
-	platform_set_drvdata(pdev, exynos_ohci);
+	platform_set_drvdata(pdev, hcd);
 
 	return 0;
 
 fail_add_hcd:
-	exynos_ohci_phy_disable(exynos_ohci);
+	exynos_ohci_phy_disable(pdev);
 fail_io:
 	clk_disable_unprepare(exynos_ohci->clk);
 fail_clk:
@@ -221,16 +182,15 @@ fail_clk:
 
 static int exynos_ohci_remove(struct platform_device *pdev)
 {
-	struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
-	struct usb_hcd *hcd = exynos_ohci->hcd;
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
+	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
 
 	usb_remove_hcd(hcd);
 
 	if (exynos_ohci->otg)
-		exynos_ohci->otg->set_host(exynos_ohci->otg,
-					&exynos_ohci->hcd->self);
+		exynos_ohci->otg->set_host(exynos_ohci->otg, &hcd->self);
 
-	exynos_ohci_phy_disable(exynos_ohci);
+	exynos_ohci_phy_disable(pdev);
 
 	clk_disable_unprepare(exynos_ohci->clk);
 
@@ -241,8 +201,7 @@ static int exynos_ohci_remove(struct platform_device *pdev)
 
 static void exynos_ohci_shutdown(struct platform_device *pdev)
 {
-	struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
-	struct usb_hcd *hcd = exynos_ohci->hcd;
+	struct usb_hcd *hcd = platform_get_drvdata(pdev);
 
 	if (hcd->driver->shutdown)
 		hcd->driver->shutdown(hcd);
@@ -251,9 +210,10 @@ static void exynos_ohci_shutdown(struct platform_device *pdev)
 #ifdef CONFIG_PM
 static int exynos_ohci_suspend(struct device *dev)
 {
-	struct exynos_ohci_hcd *exynos_ohci = dev_get_drvdata(dev);
-	struct usb_hcd *hcd = exynos_ohci->hcd;
+	struct usb_hcd *hcd = dev_get_drvdata(dev);
+	struct exynos_ohci_hcd *exynos_ohci = to_exynos_ohci(hcd);
 	struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+	struct platform_device *pdev = to_platform_device(dev);
 	unsigned long flags;
 	int rc = 0;
 
@@ -273,10 +233,9 @@ static int exynos_ohci_suspend(struct device *dev)
 	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 
 	if (exynos_ohci->otg)
-		exynos_ohci->otg->set_host(exynos_ohci->otg,
-					&exynos_ohci->hcd->self);
+		exynos_ohci->otg->set_host(exynos_ohci->otg, &hcd->self);
 
-	exynos_ohci_phy_disable(exynos_ohci);
+	exynos_ohci_phy_disable(pdev);
 
 	clk_disable_unprepare(exynos_ohci->clk);
 
@@ -288,16 +247,16 @@ fail:
 
 static int exynos_ohci_resume(struct device *dev)
 {
-	struct exynos_ohci_hcd *exynos_ohci = dev_get_drvdata(dev);
-	struct usb_hcd *hcd = exynos_ohci->hcd;
+	struct usb_hcd *hcd			= dev_get_drvdata(dev);
+	struct exynos_ohci_hcd *exynos_ohci	= to_exynos_ohci(hcd);
+	struct platform_device *pdev		= to_platform_device(dev);
 
 	clk_prepare_enable(exynos_ohci->clk);
 
 	if (exynos_ohci->otg)
-		exynos_ohci->otg->set_host(exynos_ohci->otg,
-					&exynos_ohci->hcd->self);
+		exynos_ohci->otg->set_host(exynos_ohci->otg, &hcd->self);
 
-	exynos_ohci_phy_enable(exynos_ohci);
+	exynos_ohci_phy_enable(pdev);
 
 	ohci_resume(hcd, false);
 
@@ -308,6 +267,10 @@ static int exynos_ohci_resume(struct device *dev)
 #define exynos_ohci_resume	NULL
 #endif
 
+static const struct ohci_driver_overrides exynos_overrides __initconst = {
+	.extra_priv_size =	sizeof(struct exynos_ohci_hcd),
+};
+
 static const struct dev_pm_ops exynos_ohci_pm_ops = {
 	.suspend	= exynos_ohci_suspend,
 	.resume		= exynos_ohci_resume,
@@ -333,6 +296,23 @@ static struct platform_driver exynos_ohci_driver = {
 		.of_match_table	= of_match_ptr(exynos_ohci_match),
 	}
 };
+static int __init ohci_exynos_init(void)
+{
+	if (usb_disabled())
+		return -ENODEV;
+
+	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
+	ohci_init_driver(&exynos_ohci_hc_driver, &exynos_overrides);
+	return platform_driver_register(&exynos_ohci_driver);
+}
+module_init(ohci_exynos_init);
+
+static void __exit ohci_exynos_cleanup(void)
+{
+	platform_driver_unregister(&exynos_ohci_driver);
+}
+module_exit(ohci_exynos_cleanup);
 
 MODULE_ALIAS("platform:exynos-ohci");
 MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 39c7624..14962f8 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -1178,11 +1178,6 @@ MODULE_LICENSE ("GPL");
 #define S3C2410_PLATFORM_DRIVER	ohci_hcd_s3c2410_driver
 #endif
 
-#ifdef CONFIG_USB_OHCI_EXYNOS
-#include "ohci-exynos.c"
-#define EXYNOS_PLATFORM_DRIVER	exynos_ohci_driver
-#endif
-
 #ifdef CONFIG_USB_OHCI_HCD_OMAP1
 #include "ohci-omap.c"
 #define OMAP1_PLATFORM_DRIVER	ohci_hcd_omap_driver
@@ -1260,6 +1255,7 @@ MODULE_LICENSE ("GPL");
 
 #if	!IS_ENABLED(CONFIG_USB_OHCI_HCD_PCI) &&	\
 	!IS_ENABLED(CONFIG_USB_OHCI_HCD_PLATFORM) && \
+	!IS_ENABLED(CONFIG_USB_OHCI_EXYNOS) && \
 	!defined(PLATFORM_DRIVER) &&	\
 	!defined(OMAP1_PLATFORM_DRIVER) &&	\
 	!defined(OMAP3_PLATFORM_DRIVER) &&	\
@@ -1269,7 +1265,6 @@ MODULE_LICENSE ("GPL");
 	!defined(SM501_OHCI_DRIVER) && \
 	!defined(TMIO_OHCI_DRIVER) && \
 	!defined(S3C2410_PLATFORM_DRIVER) && \
-	!defined(EXYNOS_PLATFORM_DRIVER) && \
 	!defined(EP93XX_PLATFORM_DRIVER) && \
 	!defined(AT91_PLATFORM_DRIVER) && \
 	!defined(NXP_PLATFORM_DRIVER) && \
@@ -1352,12 +1347,6 @@ static int __init ohci_hcd_mod_init(void)
 		goto error_s3c2410;
 #endif
 
-#ifdef EXYNOS_PLATFORM_DRIVER
-	retval = platform_driver_register(&EXYNOS_PLATFORM_DRIVER);
-	if (retval < 0)
-		goto error_exynos;
-#endif
-
 #ifdef EP93XX_PLATFORM_DRIVER
 	retval = platform_driver_register(&EP93XX_PLATFORM_DRIVER);
 	if (retval < 0)
@@ -1411,10 +1400,6 @@ static int __init ohci_hcd_mod_init(void)
 	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
  error_ep93xx:
 #endif
-#ifdef EXYNOS_PLATFORM_DRIVER
-	platform_driver_unregister(&EXYNOS_PLATFORM_DRIVER);
- error_exynos:
-#endif
 #ifdef S3C2410_PLATFORM_DRIVER
 	platform_driver_unregister(&S3C2410_PLATFORM_DRIVER);
  error_s3c2410:
@@ -1479,9 +1464,6 @@ static void __exit ohci_hcd_mod_exit(void)
 #ifdef EP93XX_PLATFORM_DRIVER
 	platform_driver_unregister(&EP93XX_PLATFORM_DRIVER);
 #endif
-#ifdef EXYNOS_PLATFORM_DRIVER
-	platform_driver_unregister(&EXYNOS_PLATFORM_DRIVER);
-#endif
 #ifdef S3C2410_PLATFORM_DRIVER
 	platform_driver_unregister(&S3C2410_PLATFORM_DRIVER);
 #endif
-- 
1.7.9.5