/*
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* Copyright (C) 2017 Broadcom
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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/*
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* This driver provides reset support for Broadcom FlexRM ring manager
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* to VFIO platform.
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*/
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include "vfio_platform_private.h"
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/* FlexRM configuration */
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#define RING_REGS_SIZE 0x10000
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#define RING_VER_MAGIC 0x76303031
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/* Per-Ring register offsets */
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#define RING_VER 0x000
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#define RING_CONTROL 0x034
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#define RING_FLUSH_DONE 0x038
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/* Register RING_CONTROL fields */
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#define CONTROL_FLUSH_SHIFT 5
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/* Register RING_FLUSH_DONE fields */
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#define FLUSH_DONE_MASK 0x1
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static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring)
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{
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unsigned int timeout;
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/* Disable/inactivate ring */
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writel_relaxed(0x0, ring + RING_CONTROL);
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/* Set ring flush state */
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timeout = 1000; /* timeout of 1s */
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writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL);
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do {
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if (readl_relaxed(ring + RING_FLUSH_DONE) &
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FLUSH_DONE_MASK)
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break;
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mdelay(1);
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} while (--timeout);
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if (!timeout)
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return -ETIMEDOUT;
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/* Clear ring flush state */
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timeout = 1000; /* timeout of 1s */
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writel_relaxed(0x0, ring + RING_CONTROL);
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do {
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if (!(readl_relaxed(ring + RING_FLUSH_DONE) &
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FLUSH_DONE_MASK))
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break;
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mdelay(1);
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} while (--timeout);
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if (!timeout)
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return -ETIMEDOUT;
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return 0;
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}
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static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
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{
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void __iomem *ring;
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int rc = 0, ret = 0, ring_num = 0;
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struct vfio_platform_region *reg = &vdev->regions[0];
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/* Map FlexRM ring registers if not mapped */
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if (!reg->ioaddr) {
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reg->ioaddr = ioremap_nocache(reg->addr, reg->size);
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if (!reg->ioaddr)
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return -ENOMEM;
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}
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/* Discover and shutdown each FlexRM ring */
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for (ring = reg->ioaddr;
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ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) {
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if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) {
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rc = vfio_platform_bcmflexrm_shutdown(ring);
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if (rc) {
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dev_warn(vdev->device,
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"FlexRM ring%d shutdown error %d\n",
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ring_num, rc);
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ret |= rc;
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}
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ring_num++;
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}
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}
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return ret;
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}
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module_vfio_reset_handler("brcm,iproc-flexrm-mbox",
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vfio_platform_bcmflexrm_reset);
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
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MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");
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