platform/reset/vfio_platform_calxedaxgmac.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * VFIO platform driver specialized for Calxeda xgmac reset
0004  * reset code is inherited from calxeda xgmac native driver
0005  *
0006  * Copyright 2010-2011 Calxeda, Inc.
0007  * Copyright (c) 2015 Linaro Ltd.
0008  *              www.linaro.org
0009  */
0010
0011 #include <linux/module.h>
0012 #include <linux/kernel.h>
0013 #include <linux/init.h>
0014 #include <linux/io.h>
0015
0016 #include "../vfio_platform_private.h"
0017
0018 #define DRIVER_VERSION  "0.1"
0019 #define DRIVER_AUTHOR   "Eric Auger <eric.auger@linaro.org>"
0020 #define DRIVER_DESC     "Reset support for Calxeda xgmac vfio platform device"
0021
0022 /* XGMAC Register definitions */
0023 #define XGMAC_CONTROL           0x00000000      /* MAC Configuration */
0024
0025 /* DMA Control and Status Registers */
0026 #define XGMAC_DMA_CONTROL       0x00000f18      /* Ctrl (Operational Mode) */
0027 #define XGMAC_DMA_INTR_ENA      0x00000f1c      /* Interrupt Enable */
0028
0029 /* DMA Control register defines */
0030 #define DMA_CONTROL_ST          0x00002000      /* Start/Stop Transmission */
0031 #define DMA_CONTROL_SR          0x00000002      /* Start/Stop Receive */
0032
0033 /* Common MAC defines */
0034 #define MAC_ENABLE_TX           0x00000008      /* Transmitter Enable */
0035 #define MAC_ENABLE_RX           0x00000004      /* Receiver Enable */
0036
0037 static inline void xgmac_mac_disable(void __iomem *ioaddr)
0038 {
0039     u32 value = readl(ioaddr + XGMAC_DMA_CONTROL);
0040
0041     value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
0042     writel(value, ioaddr + XGMAC_DMA_CONTROL);
0043
0044     value = readl(ioaddr + XGMAC_CONTROL);
0045     value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX);
0046     writel(value, ioaddr + XGMAC_CONTROL);
0047 }
0048
0049 static int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev)
0050 {
0051     struct vfio_platform_region *reg = &vdev->regions[0];
0052
0053     if (!reg->ioaddr) {
0054         reg->ioaddr =
0055             ioremap(reg->addr, reg->size);
0056         if (!reg->ioaddr)
0057             return -ENOMEM;
0058     }
0059
0060     /* disable IRQ */
0061     writel(0, reg->ioaddr + XGMAC_DMA_INTR_ENA);
0062
0063     /* Disable the MAC core */
0064     xgmac_mac_disable(reg->ioaddr);
0065
0066     return 0;
0067 }
0068
0069 module_vfio_reset_handler("calxeda,hb-xgmac", vfio_platform_calxedaxgmac_reset);
0070
0071 MODULE_VERSION(DRIVER_VERSION);
0072 MODULE_LICENSE("GPL v2");
0073 MODULE_AUTHOR(DRIVER_AUTHOR);
0074 MODULE_DESCRIPTION(DRIVER_DESC);