1/*
2 * VFIO platform driver specialized for Calxeda xgmac reset
3 * reset code is inherited from calxeda xgmac native driver
4 *
5 * Copyright 2010-2011 Calxeda, Inc.
6 * Copyright (c) 2015 Linaro Ltd.
7 *              www.linaro.org
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms and conditions of the GNU General Public License,
11 * version 2, as published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16 * more details.
17 *
18 * You should have received a copy of the GNU General Public License along with
19 * this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/module.h>
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/io.h>
26
27#include "vfio_platform_private.h"
28
29#define DRIVER_VERSION  "0.1"
30#define DRIVER_AUTHOR   "Eric Auger <eric.auger@linaro.org>"
31#define DRIVER_DESC     "Reset support for Calxeda xgmac vfio platform device"
32
33/* XGMAC Register definitions */
34#define XGMAC_CONTROL           0x00000000      /* MAC Configuration */
35
36/* DMA Control and Status Registers */
37#define XGMAC_DMA_CONTROL       0x00000f18      /* Ctrl (Operational Mode) */
38#define XGMAC_DMA_INTR_ENA      0x00000f1c      /* Interrupt Enable */
39
40/* DMA Control registe defines */
41#define DMA_CONTROL_ST          0x00002000      /* Start/Stop Transmission */
42#define DMA_CONTROL_SR          0x00000002      /* Start/Stop Receive */
43
44/* Common MAC defines */
45#define MAC_ENABLE_TX           0x00000008      /* Transmitter Enable */
46#define MAC_ENABLE_RX           0x00000004      /* Receiver Enable */
47
48static inline void xgmac_mac_disable(void __iomem *ioaddr)
49{
50	u32 value = readl(ioaddr + XGMAC_DMA_CONTROL);
51
52	value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
53	writel(value, ioaddr + XGMAC_DMA_CONTROL);
54
55	value = readl(ioaddr + XGMAC_CONTROL);
56	value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX);
57	writel(value, ioaddr + XGMAC_CONTROL);
58}
59
60int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev)
61{
62	struct vfio_platform_region *reg = &vdev->regions[0];
63
64	if (!reg->ioaddr) {
65		reg->ioaddr =
66			ioremap_nocache(reg->addr, reg->size);
67		if (!reg->ioaddr)
68			return -ENOMEM;
69	}
70
71	/* disable IRQ */
72	writel(0, reg->ioaddr + XGMAC_DMA_INTR_ENA);
73
74	/* Disable the MAC core */
75	xgmac_mac_disable(reg->ioaddr);
76
77	return 0;
78}
79
80module_vfio_reset_handler("calxeda,hb-xgmac", vfio_platform_calxedaxgmac_reset);
81
82MODULE_VERSION(DRIVER_VERSION);
83MODULE_LICENSE("GPL v2");
84MODULE_AUTHOR(DRIVER_AUTHOR);
85MODULE_DESCRIPTION(DRIVER_DESC);
86