298 lines
7.4 KiB
C
298 lines
7.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2017-2018 HiSilicon Limited.
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// Copyright (c) 2017-2018 Linaro Limited.
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#include <linux/bitops.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/mailbox_controller.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include "mailbox.h"
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#define MBOX_CHAN_MAX 32
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#define MBOX_RX 0x0
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#define MBOX_TX 0x1
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#define MBOX_BASE(mbox, ch) ((mbox)->base + ((ch) * 0x40))
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#define MBOX_SRC_REG 0x00
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#define MBOX_DST_REG 0x04
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#define MBOX_DCLR_REG 0x08
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#define MBOX_DSTAT_REG 0x0c
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#define MBOX_MODE_REG 0x10
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#define MBOX_IMASK_REG 0x14
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#define MBOX_ICLR_REG 0x18
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#define MBOX_SEND_REG 0x1c
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#define MBOX_DATA_REG 0x20
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#define MBOX_IPC_LOCK_REG 0xa00
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#define MBOX_IPC_UNLOCK 0x1acce551
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#define MBOX_AUTOMATIC_ACK 1
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#define MBOX_STATE_IDLE BIT(4)
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#define MBOX_STATE_READY BIT(5)
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#define MBOX_STATE_ACK BIT(7)
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#define MBOX_MSG_LEN 8
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/**
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* struct hi3660_chan_info - Hi3660 mailbox channel information
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* @dst_irq: Interrupt vector for remote processor
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* @ack_irq: Interrupt vector for local processor
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*
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* A channel can be used for TX or RX, it can trigger remote
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* processor interrupt to notify remote processor and can receive
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* interrupt if it has an incoming message.
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*/
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struct hi3660_chan_info {
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unsigned int dst_irq;
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unsigned int ack_irq;
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};
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/**
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* struct hi3660_mbox - Hi3660 mailbox controller data
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* @dev: Device to which it is attached
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* @base: Base address of the register mapping region
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* @chan: Representation of channels in mailbox controller
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* @mchan: Representation of channel info
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* @controller: Representation of a communication channel controller
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*
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* Mailbox controller includes 32 channels and can allocate
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* channel for message transferring.
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*/
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struct hi3660_mbox {
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struct device *dev;
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void __iomem *base;
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struct mbox_chan chan[MBOX_CHAN_MAX];
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struct hi3660_chan_info mchan[MBOX_CHAN_MAX];
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struct mbox_controller controller;
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};
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static struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
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{
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return container_of(mbox, struct hi3660_mbox, controller);
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}
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static int hi3660_mbox_check_state(struct mbox_chan *chan)
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{
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unsigned long ch = (unsigned long)chan->con_priv;
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struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
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struct hi3660_chan_info *mchan = &mbox->mchan[ch];
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void __iomem *base = MBOX_BASE(mbox, ch);
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unsigned long val;
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unsigned int ret;
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/* Mailbox is ready to use */
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if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY)
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return 0;
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/* Wait for acknowledge from remote */
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ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
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val, (val & MBOX_STATE_ACK), 1000, 300000);
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if (ret) {
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dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
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return ret;
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}
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/* clear ack state, mailbox will get back to ready state */
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writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG);
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return 0;
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}
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static int hi3660_mbox_unlock(struct mbox_chan *chan)
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{
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struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
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unsigned int val, retry = 3;
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do {
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writel(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
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val = readl(mbox->base + MBOX_IPC_LOCK_REG);
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if (!val)
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break;
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udelay(10);
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} while (retry--);
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if (val)
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dev_err(mbox->dev, "%s: failed to unlock mailbox\n", __func__);
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return (!val) ? 0 : -ETIMEDOUT;
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}
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static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
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{
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unsigned long ch = (unsigned long)chan->con_priv;
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struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
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struct hi3660_chan_info *mchan = &mbox->mchan[ch];
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void __iomem *base = MBOX_BASE(mbox, ch);
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unsigned int val, retry;
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for (retry = 10; retry; retry--) {
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/* Check if channel is in idle state */
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if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
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writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
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/* Check ack bit has been set successfully */
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val = readl(base + MBOX_SRC_REG);
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if (val & BIT(mchan->ack_irq))
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break;
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}
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}
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if (!retry)
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dev_err(mbox->dev, "%s: failed to acquire channel\n", __func__);
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return retry ? 0 : -ETIMEDOUT;
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}
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static int hi3660_mbox_startup(struct mbox_chan *chan)
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{
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int ret;
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ret = hi3660_mbox_unlock(chan);
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if (ret)
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return ret;
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ret = hi3660_mbox_acquire_channel(chan);
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if (ret)
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return ret;
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return 0;
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}
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static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
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{
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unsigned long ch = (unsigned long)chan->con_priv;
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struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
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struct hi3660_chan_info *mchan = &mbox->mchan[ch];
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void __iomem *base = MBOX_BASE(mbox, ch);
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u32 *buf = msg;
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unsigned int i;
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int ret;
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ret = hi3660_mbox_check_state(chan);
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if (ret)
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return ret;
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/* Clear mask for destination interrupt */
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writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG);
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/* Config destination for interrupt vector */
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writel_relaxed(BIT(mchan->dst_irq), base + MBOX_DST_REG);
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/* Automatic acknowledge mode */
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writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
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/* Fill message data */
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for (i = 0; i < MBOX_MSG_LEN; i++)
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writel_relaxed(buf[i], base + MBOX_DATA_REG + i * 4);
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/* Trigger data transferring */
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writel(BIT(mchan->ack_irq), base + MBOX_SEND_REG);
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return 0;
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}
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static const struct mbox_chan_ops hi3660_mbox_ops = {
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.startup = hi3660_mbox_startup,
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.send_data = hi3660_mbox_send_data,
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};
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static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
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const struct of_phandle_args *spec)
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{
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struct hi3660_mbox *mbox = to_hi3660_mbox(controller);
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struct hi3660_chan_info *mchan;
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unsigned int ch = spec->args[0];
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if (ch >= MBOX_CHAN_MAX) {
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dev_err(mbox->dev, "Invalid channel idx %d\n", ch);
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return ERR_PTR(-EINVAL);
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}
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mchan = &mbox->mchan[ch];
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mchan->dst_irq = spec->args[1];
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mchan->ack_irq = spec->args[2];
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return &mbox->chan[ch];
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}
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static const struct of_device_id hi3660_mbox_of_match[] = {
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{ .compatible = "hisilicon,hi3660-mbox", },
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{},
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};
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MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
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static int hi3660_mbox_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct hi3660_mbox *mbox;
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struct mbox_chan *chan;
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unsigned long ch;
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int err;
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mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
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if (!mbox)
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return -ENOMEM;
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mbox->base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(mbox->base))
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return PTR_ERR(mbox->base);
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mbox->dev = dev;
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mbox->controller.dev = dev;
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mbox->controller.chans = mbox->chan;
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mbox->controller.num_chans = MBOX_CHAN_MAX;
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mbox->controller.ops = &hi3660_mbox_ops;
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mbox->controller.of_xlate = hi3660_mbox_xlate;
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/* Initialize mailbox channel data */
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chan = mbox->chan;
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for (ch = 0; ch < MBOX_CHAN_MAX; ch++)
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chan[ch].con_priv = (void *)ch;
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err = devm_mbox_controller_register(dev, &mbox->controller);
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if (err) {
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dev_err(dev, "Failed to register mailbox %d\n", err);
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return err;
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}
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platform_set_drvdata(pdev, mbox);
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dev_info(dev, "Mailbox enabled\n");
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return 0;
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}
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static struct platform_driver hi3660_mbox_driver = {
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.probe = hi3660_mbox_probe,
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.driver = {
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.name = "hi3660-mbox",
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.of_match_table = hi3660_mbox_of_match,
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},
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};
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static int __init hi3660_mbox_init(void)
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{
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return platform_driver_register(&hi3660_mbox_driver);
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}
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core_initcall(hi3660_mbox_init);
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static void __exit hi3660_mbox_exit(void)
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{
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platform_driver_unregister(&hi3660_mbox_driver);
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}
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module_exit(hi3660_mbox_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("Hisilicon Hi3660 Mailbox Controller");
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MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
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