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https://github.com/AsahiLinux/u-boot
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456305ec59
This mailbox driver provides a communication channel with the Apple IOP controllers found on Apple SoCs. These IOP controllers are used to implement various functions such as the System Manegement Controller (SMC) and NVMe storage. It allows sending and receiving a 96-bit message over a single channel. The header file with the struct used for mailbox messages is taken straight from Linux. Signed-off-by: Mark Kettenis <kettenis@openbsd.org> Signed-off-by: Sven Peter <sven@svenpeter.dev> Reviewed-by: Simon Glass <sjg@chromium.org> Tested on: Macbook Air M1 Tested-by: Simon Glass <sjg@chromium.org>
92 lines
2.1 KiB
C
92 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2021 Mark Kettenis <kettenis@openbsd.org>
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*/
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#include <common.h>
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#include <dm.h>
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#include <mailbox-uclass.h>
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#include <asm/io.h>
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#include <linux/apple-mailbox.h>
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#include <linux/delay.h>
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#define REG_A2I_STAT 0x110
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#define REG_A2I_STAT_EMPTY BIT(17)
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#define REG_A2I_STAT_FULL BIT(16)
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#define REG_I2A_STAT 0x114
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#define REG_I2A_STAT_EMPTY BIT(17)
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#define REG_I2A_STAT_FULL BIT(16)
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#define REG_A2I_MSG0 0x800
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#define REG_A2I_MSG1 0x808
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#define REG_I2A_MSG0 0x830
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#define REG_I2A_MSG1 0x838
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struct apple_mbox_priv {
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void *base;
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};
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static int apple_mbox_of_xlate(struct mbox_chan *chan,
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struct ofnode_phandle_args *args)
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{
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if (args->args_count != 0)
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return -EINVAL;
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return 0;
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}
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static int apple_mbox_send(struct mbox_chan *chan, const void *data)
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{
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struct apple_mbox_priv *priv = dev_get_priv(chan->dev);
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const struct apple_mbox_msg *msg = data;
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writeq(msg->msg0, priv->base + REG_A2I_MSG0);
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writeq(msg->msg1, priv->base + REG_A2I_MSG1);
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while (readl(priv->base + REG_A2I_STAT) & REG_A2I_STAT_FULL)
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udelay(1);
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return 0;
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}
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static int apple_mbox_recv(struct mbox_chan *chan, void *data)
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{
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struct apple_mbox_priv *priv = dev_get_priv(chan->dev);
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struct apple_mbox_msg *msg = data;
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if (readl(priv->base + REG_I2A_STAT) & REG_I2A_STAT_EMPTY)
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return -ENODATA;
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msg->msg0 = readq(priv->base + REG_I2A_MSG0);
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msg->msg1 = readq(priv->base + REG_I2A_MSG1);
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return 0;
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}
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struct mbox_ops apple_mbox_ops = {
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.of_xlate = apple_mbox_of_xlate,
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.send = apple_mbox_send,
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.recv = apple_mbox_recv,
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};
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static int apple_mbox_probe(struct udevice *dev)
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{
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struct apple_mbox_priv *priv = dev_get_priv(dev);
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priv->base = dev_read_addr_ptr(dev);
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if (!priv->base)
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return -EINVAL;
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return 0;
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}
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static const struct udevice_id apple_mbox_of_match[] = {
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{ .compatible = "apple,asc-mailbox-v4" },
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{ /* sentinel */ }
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};
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U_BOOT_DRIVER(apple_mbox) = {
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.name = "apple-mbox",
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.id = UCLASS_MAILBOX,
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.of_match = apple_mbox_of_match,
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.probe = apple_mbox_probe,
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.priv_auto = sizeof(struct apple_mbox_priv),
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.ops = &apple_mbox_ops,
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};
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