USB: UHCI: Support non-PCI host controllers

This patch is part of a series that extend the UHCI HCD to support
non-PCI host controllers.

This patch also extends the uhci_{read,write}* functions to allow accesses
to registers not mapped into PCI I/O space. This extension also includes
the addition of a void __iomem pointer to the uhci structure.

A new Kconfig option is added to signal that the system has a non-PCI HC.
If this Kconfig option is set, uhci-hcd.c will include generic reset functions
for systems that do not make use of keyboard and mouse legacy support. PCI
controllers will still always use the reset functions from pci-quirks

This patch is followed by a patch that adds bus glue for the first non-PCI
UHCI HC.

Signed-off-by: Jan Andersson <jan@gaisler.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 142 insertions, 0 deletions

diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 7dd4c44..8045988 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -410,6 +410,10 @@ config USB_UHCI_HCD
 	  To compile this driver as a module, choose M here: the
 	  module will be called uhci-hcd.
 
+config USB_UHCI_SUPPORT_NON_PCI_HC
+	bool
+	depends on USB_UHCI_HCD
+
 config USB_FHCI_HCD
 	tristate "Freescale QE USB Host Controller support"
 	depends on USB && OF_GPIO && QE_GPIO && QUICC_ENGINE
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index 5176c53..cd482fc 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -167,6 +167,79 @@ static void check_and_reset_hc(struct uhci_hcd *uhci)
 		finish_reset(uhci);
 }
 
+#if defined(CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC)
+/*
+ * The two functions below are generic reset functions that are used on systems
+ * that do not have keyboard and mouse legacy support. We assume that we are
+ * running on such a system if CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC is defined.
+ */
+
+/*
+ * Make sure the controller is completely inactive, unable to
+ * generate interrupts or do DMA.
+ */
+static void uhci_generic_reset_hc(struct uhci_hcd *uhci)
+{
+	/* Reset the HC - this will force us to get a
+	 * new notification of any already connected
+	 * ports due to the virtual disconnect that it
+	 * implies.
+	 */
+	uhci_writew(uhci, USBCMD_HCRESET, USBCMD);
+	mb();
+	udelay(5);
+	if (uhci_readw(uhci, USBCMD) & USBCMD_HCRESET)
+		dev_warn(uhci_dev(uhci), "HCRESET not completed yet!\n");
+
+	/* Just to be safe, disable interrupt requests and
+	 * make sure the controller is stopped.
+	 */
+	uhci_writew(uhci, 0, USBINTR);
+	uhci_writew(uhci, 0, USBCMD);
+}
+
+/*
+ * Initialize a controller that was newly discovered or has just been
+ * resumed.  In either case we can't be sure of its previous state.
+ *
+ * Returns: 1 if the controller was reset, 0 otherwise.
+ */
+static int uhci_generic_check_and_reset_hc(struct uhci_hcd *uhci)
+{
+	unsigned int cmd, intr;
+
+	/*
+	 * When restarting a suspended controller, we expect all the
+	 * settings to be the same as we left them:
+	 *
+	 *	Controller is stopped and configured with EGSM set;
+	 *	No interrupts enabled except possibly Resume Detect.
+	 *
+	 * If any of these conditions are violated we do a complete reset.
+	 */
+
+	cmd = uhci_readw(uhci, USBCMD);
+	if ((cmd & USBCMD_RS) || !(cmd & USBCMD_CF) || !(cmd & USBCMD_EGSM)) {
+		dev_dbg(uhci_dev(uhci), "%s: cmd = 0x%04x\n",
+				__func__, cmd);
+		goto reset_needed;
+	}
+
+	intr = uhci_readw(uhci, USBINTR);
+	if (intr & (~USBINTR_RESUME)) {
+		dev_dbg(uhci_dev(uhci), "%s: intr = 0x%04x\n",
+				__func__, intr);
+		goto reset_needed;
+	}
+	return 0;
+
+reset_needed:
+	dev_dbg(uhci_dev(uhci), "Performing full reset\n");
+	uhci_generic_reset_hc(uhci);
+	return 1;
+}
+#endif /* CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC */
+
 /*
  * Store the basic register settings needed by the controller.
  */
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index a6de241..a4e64d0 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -380,6 +380,9 @@ struct uhci_hcd {
 	/* Grabbed from PCI */
 	unsigned long io_addr;
 
+	/* Used when registers are memory mapped */
+	void __iomem *regs;
+
 	struct dma_pool *qh_pool;
 	struct dma_pool *td_pool;
 
@@ -481,6 +484,14 @@ struct urb_priv {
 #define PCI_VENDOR_ID_GENESYS		0x17a0
 #define PCI_DEVICE_ID_GL880S_UHCI	0x8083
 
+/*
+ * Functions used to access controller registers. The UCHI spec says that host
+ * controller I/O registers are mapped into PCI I/O space. For non-PCI hosts
+ * we use memory mapped registers.
+ */
+
+#if !defined(CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC)
+/* Support PCI only */
 static inline u32 uhci_readl(struct uhci_hcd *uhci, int reg)
 {
 	return inl(uhci->io_addr + reg);
@@ -511,4 +522,58 @@ static inline void uhci_writeb(struct uhci_hcd *uhci, u8 val, int reg)
 	outb(val, uhci->io_addr + reg);
 }
 
+#else
+/* Support PCI and non-PCI host controllers */
+
+#define uhci_has_pci_registers(u)	((u)->io_addr != 0)
+
+static inline u32 uhci_readl(struct uhci_hcd *uhci, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		return inl(uhci->io_addr + reg);
+	else
+		return readl(uhci->regs + reg);
+}
+
+static inline void uhci_writel(struct uhci_hcd *uhci, u32 val, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		outl(val, uhci->io_addr + reg);
+	else
+		writel(val, uhci->regs + reg);
+}
+
+static inline u16 uhci_readw(struct uhci_hcd *uhci, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		return inw(uhci->io_addr + reg);
+	else
+		return readw(uhci->regs + reg);
+}
+
+static inline void uhci_writew(struct uhci_hcd *uhci, u16 val, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		outw(val, uhci->io_addr + reg);
+	else
+		writew(val, uhci->regs + reg);
+}
+
+static inline u8 uhci_readb(struct uhci_hcd *uhci, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		return inb(uhci->io_addr + reg);
+	else
+		return readb(uhci->regs + reg);
+}
+
+static inline void uhci_writeb(struct uhci_hcd *uhci, u8 val, int reg)
+{
+	if (uhci_has_pci_registers(uhci))
+		outb(val, uhci->io_addr + reg);
+	else
+		writeb(val, uhci->regs + reg);
+}
+#endif /* !defined(CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC) */
+
 #endif