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 
48 static 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 
60 static int 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 
80 module_vfio_reset_handler("calxeda,hb-xgmac", vfio_platform_calxedaxgmac_reset);
81 
82 MODULE_VERSION(DRIVER_VERSION);
83 MODULE_LICENSE("GPL v2");
84 MODULE_AUTHOR(DRIVER_AUTHOR);
85 MODULE_DESCRIPTION(DRIVER_DESC);
86