#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>

#define RTL815x_REQT_READ	0xc0
#define RTL815x_REQT_WRITE	0x40
#define RTL815x_REQ_GET_REGS	0x05
#define RTL815x_REQ_SET_REGS	0x05

#define MCU_TYPE_PLA		0x0100
#define OCP_BASE		0xe86c
#define BASE_MII		0xa400

#define BYTE_EN_DWORD		0xff
#define BYTE_EN_WORD		0x33
#define BYTE_EN_BYTE		0x11

#define R815x_PHY_ID		32
#define REALTEK_VENDOR_ID	0x0bda


static int pla_read_word(struct usb_device *udev, u16 index)
{
	int ret;
	u8 shift = index & 2;
	__le32 *tmp;

	tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	index &= ~3;

	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			      RTL815x_REQ_GET_REGS, RTL815x_REQT_READ,
			      index, MCU_TYPE_PLA, tmp, sizeof(*tmp), 500);
	if (ret < 0)
		goto out2;

	ret = __le32_to_cpu(*tmp);
	ret >>= (shift * 8);
	ret &= 0xffff;

out2:
	kfree(tmp);
	return ret;
}

static int pla_write_word(struct usb_device *udev, u16 index, u32 data)
{
	__le32 *tmp;
	u32 mask = 0xffff;
	u16 byen = BYTE_EN_WORD;
	u8 shift = index & 2;
	int ret;

	tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	data &= mask;

	if (shift) {
		byen <<= shift;
		mask <<= (shift * 8);
		data <<= (shift * 8);
		index &= ~3;
	}

	ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0),
			      RTL815x_REQ_GET_REGS, RTL815x_REQT_READ,
			      index, MCU_TYPE_PLA, tmp, sizeof(*tmp), 500);
	if (ret < 0)
		goto out3;

	data |= __le32_to_cpu(*tmp) & ~mask;
	*tmp = __cpu_to_le32(data);

	ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
			      RTL815x_REQ_SET_REGS, RTL815x_REQT_WRITE,
			      index, MCU_TYPE_PLA | byen, tmp, sizeof(*tmp),
			      500);

out3:
	kfree(tmp);
	return ret;
}

static int ocp_reg_read(struct usbnet *dev, u16 addr)
{
	u16 ocp_base, ocp_index;
	int ret;

	ocp_base = addr & 0xf000;
	ret = pla_write_word(dev->udev, OCP_BASE, ocp_base);
	if (ret < 0)
		goto out;

	ocp_index = (addr & 0x0fff) | 0xb000;
	ret = pla_read_word(dev->udev, ocp_index);

out:
	return ret;
}

static int ocp_reg_write(struct usbnet *dev, u16 addr, u16 data)
{
	u16 ocp_base, ocp_index;
	int ret;

	ocp_base = addr & 0xf000;
	ret = pla_write_word(dev->udev, OCP_BASE, ocp_base);
	if (ret < 0)
		goto out1;

	ocp_index = (addr & 0x0fff) | 0xb000;
	ret = pla_write_word(dev->udev, ocp_index, data);

out1:
	return ret;
}

static int r815x_mdio_read(struct net_device *netdev, int phy_id, int reg)
{
	struct usbnet *dev = netdev_priv(netdev);
	int ret;

	if (phy_id != R815x_PHY_ID)
		return -EINVAL;

	if (usb_autopm_get_interface(dev->intf) < 0)
		return -ENODEV;

	ret = ocp_reg_read(dev, BASE_MII + reg * 2);

	usb_autopm_put_interface(dev->intf);
	return ret;
}

static
void r815x_mdio_write(struct net_device *netdev, int phy_id, int reg, int val)
{
	struct usbnet *dev = netdev_priv(netdev);

	if (phy_id != R815x_PHY_ID)
		return;

	if (usb_autopm_get_interface(dev->intf) < 0)
		return;

	ocp_reg_write(dev, BASE_MII + reg * 2, val);

	usb_autopm_put_interface(dev->intf);
}

static int r8153_bind(struct usbnet *dev, struct usb_interface *intf)
{
	int status;

	status = usbnet_cdc_bind(dev, intf);
	if (status < 0)
		return status;

	dev->mii.dev = dev->net;
	dev->mii.mdio_read = r815x_mdio_read;
	dev->mii.mdio_write = r815x_mdio_write;
	dev->mii.phy_id_mask = 0x3f;
	dev->mii.reg_num_mask = 0x1f;
	dev->mii.phy_id = R815x_PHY_ID;
	dev->mii.supports_gmii = 1;

	return status;
}

static int r8152_bind(struct usbnet *dev, struct usb_interface *intf)
{
	int status;

	status = usbnet_cdc_bind(dev, intf);
	if (status < 0)
		return status;

	dev->mii.dev = dev->net;
	dev->mii.mdio_read = r815x_mdio_read;
	dev->mii.mdio_write = r815x_mdio_write;
	dev->mii.phy_id_mask = 0x3f;
	dev->mii.reg_num_mask = 0x1f;
	dev->mii.phy_id = R815x_PHY_ID;
	dev->mii.supports_gmii = 0;

	return status;
}

static const struct driver_info r8152_info = {
	.description =	"RTL8152 ECM Device",
	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT,
	.bind =		r8152_bind,
	.unbind =	usbnet_cdc_unbind,
	.status =	usbnet_cdc_status,
	.manage_power =	usbnet_manage_power,
};

static const struct driver_info r8153_info = {
	.description =	"RTL8153 ECM Device",
	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT,
	.bind =		r8153_bind,
	.unbind =	usbnet_cdc_unbind,
	.status =	usbnet_cdc_status,
	.manage_power =	usbnet_manage_power,
};

static const struct usb_device_id products[] = {
{
	USB_DEVICE_AND_INTERFACE_INFO(REALTEK_VENDOR_ID, 0x8152, USB_CLASS_COMM,
			USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
#if defined(CONFIG_USB_RTL8152) || defined(CONFIG_USB_RTL8152_MODULE)
	.driver_info = 0,
#else
	.driver_info = (unsigned long) &r8152_info,
#endif
},

{
	USB_DEVICE_AND_INTERFACE_INFO(REALTEK_VENDOR_ID, 0x8153, USB_CLASS_COMM,
			USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
#if defined(CONFIG_USB_RTL8153) || defined(CONFIG_USB_RTL8153_MODULE)
	.driver_info = 0,
#else
	.driver_info = (unsigned long) &r8153_info,
#endif
},

	{ },		/* END */
};
MODULE_DEVICE_TABLE(usb, products);

static struct usb_driver r815x_driver = {
	.name =		"r815x",
	.id_table =	products,
	.probe =	usbnet_probe,
	.disconnect =	usbnet_disconnect,
	.suspend =	usbnet_suspend,
	.resume =	usbnet_resume,
	.reset_resume =	usbnet_resume,
	.supports_autosuspend = 1,
	.disable_hub_initiated_lpm = 1,
};

module_usb_driver(r815x_driver);

MODULE_AUTHOR("Hayes Wang");
MODULE_DESCRIPTION("Realtek USB ECM device");
MODULE_LICENSE("GPL");