drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c

   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(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);