1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VFIO platform driver specialized for Calxeda xgmac reset
4  * reset code is inherited from calxeda xgmac native driver
5  *
6  * Copyright 2010-2011 Calxeda, Inc.
7  * Copyright (c) 2015 Linaro Ltd.
8  *              www.linaro.org
9  */
10 
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 
16 #include "../vfio_platform_private.h"
17 
18 #define DRIVER_VERSION  "0.1"
19 #define DRIVER_AUTHOR   "Eric Auger <eric.auger@linaro.org>"
20 #define DRIVER_DESC     "Reset support for Calxeda xgmac vfio platform device"
21 
22 /* XGMAC Register definitions */
23 #define XGMAC_CONTROL           0x00000000      /* MAC Configuration */
24 
25 /* DMA Control and Status Registers */
26 #define XGMAC_DMA_CONTROL       0x00000f18      /* Ctrl (Operational Mode) */
27 #define XGMAC_DMA_INTR_ENA      0x00000f1c      /* Interrupt Enable */
28 
29 /* DMA Control registe defines */
30 #define DMA_CONTROL_ST          0x00002000      /* Start/Stop Transmission */
31 #define DMA_CONTROL_SR          0x00000002      /* Start/Stop Receive */
32 
33 /* Common MAC defines */
34 #define MAC_ENABLE_TX           0x00000008      /* Transmitter Enable */
35 #define MAC_ENABLE_RX           0x00000004      /* Receiver Enable */
36 
37 static inline void xgmac_mac_disable(void __iomem *ioaddr)
38 {
39 	u32 value = readl(ioaddr + XGMAC_DMA_CONTROL);
40 
41 	value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
42 	writel(value, ioaddr + XGMAC_DMA_CONTROL);
43 
44 	value = readl(ioaddr + XGMAC_CONTROL);
45 	value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX);
46 	writel(value, ioaddr + XGMAC_CONTROL);
47 }
48 
49 static int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev)
50 {
51 	struct vfio_platform_region *reg = &vdev->regions[0];
52 
53 	if (!reg->ioaddr) {
54 		reg->ioaddr =
55 			ioremap_nocache(reg->addr, reg->size);
56 		if (!reg->ioaddr)
57 			return -ENOMEM;
58 	}
59 
60 	/* disable IRQ */
61 	writel(0, reg->ioaddr + XGMAC_DMA_INTR_ENA);
62 
63 	/* Disable the MAC core */
64 	xgmac_mac_disable(reg->ioaddr);
65 
66 	return 0;
67 }
68 
69 module_vfio_reset_handler("calxeda,hb-xgmac", vfio_platform_calxedaxgmac_reset);
70 
71 MODULE_VERSION(DRIVER_VERSION);
72 MODULE_LICENSE("GPL v2");
73 MODULE_AUTHOR(DRIVER_AUTHOR);
74 MODULE_DESCRIPTION(DRIVER_DESC);
75