usb: dwc3: add ULPI interface support

Registers DWC3's ULPI interface with the ULPI bus when it's
available.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/ulpi.c b/drivers/usb/dwc3/ulpi.c
new file mode 100644
index 000000000000..ec004c6d76f2
--- /dev/null
+++ b/drivers/usb/dwc3/ulpi.c
@@ -0,0 +1,91 @@
+/**
+ * ulpi.c - DesignWare USB3 Controller's ULPI PHY interface
+ *
+ * Copyright (C) 2015 Intel Corporation
+ *
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ulpi/regs.h>
+
+#include "core.h"
+#include "io.h"
+
+#define DWC3_ULPI_ADDR(a) \
+                ((a >= ULPI_EXT_VENDOR_SPECIFIC) ? \
+                DWC3_GUSB2PHYACC_ADDR(ULPI_ACCESS_EXTENDED) | \
+                DWC3_GUSB2PHYACC_EXTEND_ADDR(a) : DWC3_GUSB2PHYACC_ADDR(a))
+
+static int dwc3_ulpi_busyloop(struct dwc3 *dwc)
+{
+        unsigned count = 1000;
+        u32 reg;
+
+        while (count--) {
+                reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
+                if (!(reg & DWC3_GUSB2PHYACC_BUSY))
+                        return 0;
+                cpu_relax();
+        }
+
+        return -ETIMEDOUT;
+}
+
+static int dwc3_ulpi_read(struct ulpi_ops *ops, u8 addr)
+{
+        struct dwc3 *dwc = dev_get_drvdata(ops->dev);
+        u32 reg;
+        int ret;
+
+        reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
+        dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
+
+        ret = dwc3_ulpi_busyloop(dwc);
+        if (ret)
+                return ret;
+
+        reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYACC(0));
+
+        return DWC3_GUSB2PHYACC_DATA(reg);
+}
+
+static int dwc3_ulpi_write(struct ulpi_ops *ops, u8 addr, u8 val)
+{
+        struct dwc3 *dwc = dev_get_drvdata(ops->dev);
+        u32 reg;
+
+        reg = DWC3_GUSB2PHYACC_NEWREGREQ | DWC3_ULPI_ADDR(addr);
+        reg |= DWC3_GUSB2PHYACC_WRITE | val;
+        dwc3_writel(dwc->regs, DWC3_GUSB2PHYACC(0), reg);
+
+        return dwc3_ulpi_busyloop(dwc);
+}
+
+static struct ulpi_ops dwc3_ulpi_ops = {
+        .read = dwc3_ulpi_read,
+        .write = dwc3_ulpi_write,
+};
+
+int dwc3_ulpi_init(struct dwc3 *dwc)
+{
+        /* Register the interface */
+        dwc->ulpi = ulpi_register_interface(dwc->dev, &dwc3_ulpi_ops);
+        if (IS_ERR(dwc->ulpi)) {
+                dev_err(dwc->dev, "failed to register ULPI interface");
+                return PTR_ERR(dwc->ulpi);
+        }
+
+        return 0;
+}
+
+void dwc3_ulpi_exit(struct dwc3 *dwc)
+{
+        if (dwc->ulpi) {
+                ulpi_unregister_interface(dwc->ulpi);
+                dwc->ulpi = NULL;
+        }
+}