platform/reset/vfio_platform_amdxgbe.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * VFIO platform driver specialized for AMD xgbe reset
0004  * reset code is inherited from AMD xgbe native driver
0005  *
0006  * Copyright (c) 2015 Linaro Ltd.
0007  *              www.linaro.org
0008  */
0009
0010 #include <linux/module.h>
0011 #include <linux/kernel.h>
0012 #include <linux/init.h>
0013 #include <linux/io.h>
0014 #include <uapi/linux/mdio.h>
0015 #include <linux/delay.h>
0016
0017 #include "../vfio_platform_private.h"
0018
0019 #define DMA_MR          0x3000
0020 #define MAC_VR          0x0110
0021 #define DMA_ISR         0x3008
0022 #define MAC_ISR         0x00b0
0023 #define PCS_MMD_SELECT      0xff
0024 #define MDIO_AN_INT     0x8002
0025 #define MDIO_AN_INTMASK     0x8001
0026
0027 static unsigned int xmdio_read(void __iomem *ioaddr, unsigned int mmd,
0028                    unsigned int reg)
0029 {
0030     unsigned int mmd_address, value;
0031
0032     mmd_address = (mmd << 16) | ((reg) & 0xffff);
0033     iowrite32(mmd_address >> 8, ioaddr + (PCS_MMD_SELECT << 2));
0034     value = ioread32(ioaddr + ((mmd_address & 0xff) << 2));
0035     return value;
0036 }
0037
0038 static void xmdio_write(void __iomem *ioaddr, unsigned int mmd,
0039             unsigned int reg, unsigned int value)
0040 {
0041     unsigned int mmd_address;
0042
0043     mmd_address = (mmd << 16) | ((reg) & 0xffff);
0044     iowrite32(mmd_address >> 8, ioaddr + (PCS_MMD_SELECT << 2));
0045     iowrite32(value, ioaddr + ((mmd_address & 0xff) << 2));
0046 }
0047
0048 static int vfio_platform_amdxgbe_reset(struct vfio_platform_device *vdev)
0049 {
0050     struct vfio_platform_region *xgmac_regs = &vdev->regions[0];
0051     struct vfio_platform_region *xpcs_regs = &vdev->regions[1];
0052     u32 dma_mr_value, pcs_value, value;
0053     unsigned int count;
0054
0055     if (!xgmac_regs->ioaddr) {
0056         xgmac_regs->ioaddr =
0057             ioremap(xgmac_regs->addr, xgmac_regs->size);
0058         if (!xgmac_regs->ioaddr)
0059             return -ENOMEM;
0060     }
0061     if (!xpcs_regs->ioaddr) {
0062         xpcs_regs->ioaddr =
0063             ioremap(xpcs_regs->addr, xpcs_regs->size);
0064         if (!xpcs_regs->ioaddr)
0065             return -ENOMEM;
0066     }
0067
0068     /* reset the PHY through MDIO*/
0069     pcs_value = xmdio_read(xpcs_regs->ioaddr, MDIO_MMD_PCS, MDIO_CTRL1);
0070     pcs_value |= MDIO_CTRL1_RESET;
0071     xmdio_write(xpcs_regs->ioaddr, MDIO_MMD_PCS, MDIO_CTRL1, pcs_value);
0072
0073     count = 50;
0074     do {
0075         msleep(20);
0076         pcs_value = xmdio_read(xpcs_regs->ioaddr, MDIO_MMD_PCS,
0077                     MDIO_CTRL1);
0078     } while ((pcs_value & MDIO_CTRL1_RESET) && --count);
0079
0080     if (pcs_value & MDIO_CTRL1_RESET)
0081         dev_warn(vdev->device, "%s: XGBE PHY reset timeout\n",
0082              __func__);
0083
0084     /* disable auto-negotiation */
0085     value = xmdio_read(xpcs_regs->ioaddr, MDIO_MMD_AN, MDIO_CTRL1);
0086     value &= ~MDIO_AN_CTRL1_ENABLE;
0087     xmdio_write(xpcs_regs->ioaddr, MDIO_MMD_AN, MDIO_CTRL1, value);
0088
0089     /* disable AN IRQ */
0090     xmdio_write(xpcs_regs->ioaddr, MDIO_MMD_AN, MDIO_AN_INTMASK, 0);
0091
0092     /* clear AN IRQ */
0093     xmdio_write(xpcs_regs->ioaddr, MDIO_MMD_AN, MDIO_AN_INT, 0);
0094
0095     /* MAC software reset */
0096     dma_mr_value = ioread32(xgmac_regs->ioaddr + DMA_MR);
0097     dma_mr_value |= 0x1;
0098     iowrite32(dma_mr_value, xgmac_regs->ioaddr + DMA_MR);
0099
0100     usleep_range(10, 15);
0101
0102     count = 2000;
0103     while (--count && (ioread32(xgmac_regs->ioaddr + DMA_MR) & 1))
0104         usleep_range(500, 600);
0105
0106     if (!count)
0107         dev_warn(vdev->device, "%s: MAC SW reset failed\n", __func__);
0108
0109     return 0;
0110 }
0111
0112 module_vfio_reset_handler("amd,xgbe-seattle-v1a", vfio_platform_amdxgbe_reset);
0113
0114 MODULE_VERSION("0.1");
0115 MODULE_LICENSE("GPL v2");
0116 MODULE_AUTHOR("Eric Auger <eric.auger@linaro.org>");
0117 MODULE_DESCRIPTION("Reset support for AMD xgbe vfio platform device");