[PATCH 1/3] driver: mailbox: add support for Hi3660

Jassi Brar
2017-10-25T04:17:34Z

On Mon, Aug 7, 2017 at 2:47 PM, Zhong Kaihua <zhongkaihua@huawei.com> wrote:
> From: Kaihua Zhong <zhongkaihua@huawei.com>
>
> Add mailbox driver for Hi3660.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> Signed-off-by: Ruyi Wang <wangruyi@huawei.com>
> Tested-by: Kaihua Zhong <zhongkaihua@huawei.com>
>
> ---
> drivers/mailbox/Kconfig | 6 +
> drivers/mailbox/Makefile | 2 +
> drivers/mailbox/hi3660-mailbox.c | 688 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 696 insertions(+)
> create mode 100644 drivers/mailbox/hi3660-mailbox.c
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index ee1a3d9..778ba85 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -116,6 +116,12 @@ config HI6220_MBOX
> between application processors and MCU. Say Y here if you want to
> build Hi6220 mailbox controller driver.
>
> +config HI3660_MBOX
> + tristate "Hi3660 Mailbox"
> + depends on ARCH_HISI
> + help
> + Mailbox implementation for Hi3660.
> +
> config MAILBOX_TEST
> tristate "Mailbox Test Client"
> depends on OF
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index e2bcb03..f1c2fc4 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -28,6 +28,8 @@ obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
>
> obj-$(CONFIG_HI6220_MBOX) += hi6220-mailbox.o
>
> +obj-$(CONFIG_HI3660_MBOX) += hi3660-mailbox.o
> +
> obj-$(CONFIG_BCM_PDC_MBOX) += bcm-pdc-mailbox.o
>
> obj-$(CONFIG_BCM_FLEXRM_MBOX) += bcm-flexrm-mailbox.o
> diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c
> new file mode 100644
> index 0000000..14f469d
> --- /dev/null
> +++ b/drivers/mailbox/hi3660-mailbox.c
> @@ -0,0 +1,688 @@
> +/*
> + * Hisilicon's Hi3660 mailbox driver
> + *
> + * Copyright (c) 2017 Hisilicon Limited.
> + * Copyright (c) 2017 Linaro Limited.
> + *
> + * Author: Leo Yan <leo.yan@linaro.org>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kfifo.h>
> +#include <linux/mailbox_controller.h>
> +#include <linux/mailbox_client.h>
>
no client.h please

> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/delay.h>
> +
> +#include "mailbox.h"
> +
> +#define MBOX_CHAN_MAX 32
> +
> +#define MBOX_TX 0x1
> +
> +/* Mailbox message length: 2 words */
> +#define MBOX_MSG_LEN 2
> +
> +#define MBOX_OFF(m) (0x40 * (m))
> +#define MBOX_SRC_REG(m) MBOX_OFF(m)
> +#define MBOX_DST_REG(m) (MBOX_OFF(m) + 0x04)
> +#define MBOX_DCLR_REG(m) (MBOX_OFF(m) + 0x08)
> +#define MBOX_DSTAT_REG(m) (MBOX_OFF(m) + 0x0C)
> +#define MBOX_MODE_REG(m) (MBOX_OFF(m) + 0x10)
> +#define MBOX_IMASK_REG(m) (MBOX_OFF(m) + 0x14)
> +#define MBOX_ICLR_REG(m) (MBOX_OFF(m) + 0x18)
> +#define MBOX_SEND_REG(m) (MBOX_OFF(m) + 0x1C)
> +#define MBOX_DATA_REG(m, i) (MBOX_OFF(m) + 0x20 + ((i) << 2))
> +
> +#define MBOX_CPU_IMASK(cpu) (((cpu) << 3) + 0x800)
> +#define MBOX_CPU_IRST(cpu) (((cpu) << 3) + 0x804)
> +#define MBOX_IPC_LOCK (0xA00)
> +
> +#define MBOX_IPC_UNLOCKED 0x00000000
> +#define AUTOMATIC_ACK_CONFIG (1 << 0)
> +#define NO_FUNC_CONFIG (0 << 0)
> +
> +#define MBOX_MANUAL_ACK 0
> +#define MBOX_AUTO_ACK 1
> +
> +#define MBOX_STATE_IDLE (1 << 4)
> +#define MBOX_STATE_OUT (1 << 5)
> +#define MBOX_STATE_IN (1 << 6)
> +#define MBOX_STATE_ACK (1 << 7)
> +
> +#define MBOX_DESTINATION_STATUS (1 << 6)
> +
BIT(x) please

> +struct hi3660_mbox_chan {
> +
> + /*
> + * Description for channel's hardware info:
> + * - direction: tx or rx
> + * - dst irq: peer core's irq number
> + * - ack irq: local irq number
> + * - slot number
> + */
> + unsigned int dir, dst_irq, ack_irq;
> + unsigned int slot;
> +
> + unsigned int *buf;
> +
I think you mean u32 *buf

> + unsigned int irq_mode;
> +
> + struct hi3660_mbox *parent;
>
You could get 'struct mbox_controller *' from 'struct mbox_chan' and
use container_of to get 'struct hi3660_mbox *'

> +};
> +
> +struct hi3660_mbox {
> + struct device *dev;
> +
> + int irq;
> +
> + /* flag of enabling tx's irq mode */
> + bool tx_irq_mode;
> +
> + /* region for mailbox */
> + void __iomem *base;
> +
> + unsigned int chan_num;
> + struct hi3660_mbox_chan *mchan;
>
Since it is always going to be exactly MBOX_CHAN_MAX elements, maybe
have them here as
struct hi3660_mbox_chan mchan[MBOX_CHAN_MAX];

> + void *irq_map_chan[MBOX_CHAN_MAX];
> + struct mbox_chan *chan;
>
similarly have struct mbox_chan chan[MBOX_CHAN_MAX]
and see if you can do without irq_map_chan then.

> + struct mbox_controller controller;
> +};
> +
> +static inline void __ipc_lock(void __iomem *base, unsigned int lock_key)
> +{
> + pr_debug("%s: base %p key %d\n", __func__, base, lock_key);
> +
> + __raw_writel(lock_key, base + MBOX_IPC_LOCK);
> +}
> +
> +static inline void __ipc_unlock(void __iomem *base, unsigned int key)
> +{
> + pr_debug("%s: base %p key %d\n", __func__, base, key);
> +
> + __raw_writel(key, base + MBOX_IPC_LOCK);
> +}
> +
> +static inline unsigned int __ipc_lock_status(void __iomem *base)
> +{
> + pr_debug("%s: base %p status %d\n",
> + __func__, base, __raw_readl(base + MBOX_IPC_LOCK));
> +
> + return __raw_readl(base + MBOX_IPC_LOCK);
> +}
> +
> +static inline void __ipc_set_src(void __iomem *base, int source, int mdev)
> +{
> + pr_debug("%s: base %p src %x mdev %d\n",
> + __func__, base, source, mdev);
> +
> + __raw_writel(BIT(source), base + MBOX_SRC_REG(mdev));
> +}
> +
> +static inline unsigned int __ipc_read_src(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p src %x mdev %d\n",
> + __func__, base, __raw_readl(base + MBOX_SRC_REG(mdev)), mdev);
> +
> + return __raw_readl(base + MBOX_SRC_REG(mdev));
> +}
> +
> +static inline void __ipc_set_des(void __iomem *base, int source, int mdev)
> +{
> + pr_debug("%s: base %p src %x mdev %d\n",
> + __func__, base, source, mdev);
> +
> + __raw_writel(BIT(source), base + MBOX_DST_REG(mdev));
> +}
> +
> +static inline void __ipc_clr_des(void __iomem *base, int source, int mdev)
> +{
> + pr_debug("%s: base %p src %x mdev %d\n",
> + __func__, base, source, mdev);
> +
> + __raw_writel(BIT(source), base + MBOX_DCLR_REG(mdev));
> +}
> +
> +static inline unsigned int __ipc_des_status(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p src %x mdev %d\n",
> + __func__, base, __raw_readl(base + MBOX_DSTAT_REG(mdev)), mdev);
> +
> + return __raw_readl(base + MBOX_DSTAT_REG(mdev));
> +}
> +
> +static inline void __ipc_send(void __iomem *base, unsigned int tosend, int mdev)
> +{
> + pr_debug("%s: base %p tosend %x mdev %d\n",
> + __func__, base, tosend, mdev);
> +
> + __raw_writel(tosend, base + MBOX_SEND_REG(mdev));
> +}
> +
> +static inline unsigned int __ipc_read(void __iomem *base, int mdev, int index)
> +{
> + pr_debug("%s: base %p index %d data %x mdev %d\n",
> + __func__, base, index, __raw_readl(base + MBOX_DATA_REG(mdev, index)), mdev);
> +
> + return __raw_readl(base + MBOX_DATA_REG(mdev, index));
> +}
> +
> +static inline void __ipc_write(void __iomem *base, u32 data, int mdev, int index)
> +{
> + pr_debug("%s: base %p index %d data %x mdev %d\n",
> + __func__, base, index, data, mdev);
> +
> + __raw_writel(data, base + MBOX_DATA_REG(mdev, index));
> +}
> +
> +static inline unsigned int __ipc_cpu_imask_get(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p imask %x mdev %d\n",
> + __func__, base, __raw_readl(base + MBOX_IMASK_REG(mdev)), mdev);
> +
> + return __raw_readl(base + MBOX_IMASK_REG(mdev));
> +}
> +
> +static inline void __ipc_cpu_imask_clr(void __iomem *base, unsigned int toclr, int mdev)
> +{
> + unsigned int reg;
> +
> + pr_debug("%s: base %p toclr %x mdev %d\n",
> + __func__, base, toclr, mdev);
> +
> + reg = __raw_readl(base + MBOX_IMASK_REG(mdev));
> + reg = reg & (~(toclr));
>
reg &= ~(toclr);

> +
> + __raw_writel(reg, base + MBOX_IMASK_REG(mdev));
> +}
> +
> +static inline void __ipc_cpu_imask_all(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p mdev %d\n", __func__, base, mdev);
> +
> + __raw_writel((~0), base + MBOX_IMASK_REG(mdev));
> +}
> +
> +static inline void __ipc_cpu_iclr(void __iomem *base, unsigned int toclr, int mdev)
> +{
> + pr_debug("%s: base %p toclr %x mdev %d\n",
> + __func__, base, toclr, mdev);
> +
> + __raw_writel(toclr, base + MBOX_ICLR_REG(mdev));
> +}
> +
> +static inline int __ipc_cpu_istatus(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p mdev %d\n", __func__, base, mdev);
> +
> + return __raw_readl(base + MBOX_ICLR_REG(mdev));
> +}
> +
> +static inline unsigned int __ipc_mbox_istatus(void __iomem *base, int cpu)
> +{
> + pr_debug("%s: base %p cpu %d\n", __func__, base, cpu);
> +
> + return __raw_readl(base + MBOX_CPU_IMASK(cpu));
> +}
> +
> +static inline unsigned int __ipc_mbox_irstatus(void __iomem *base, int cpu)
> +{
> + pr_debug("%s: base %p cpu %d\n", __func__, base, cpu);
> +
> + return __raw_readl(base + MBOX_CPU_IRST(cpu));
> +}
> +
> +static inline unsigned int __ipc_status(void __iomem *base, int mdev)
> +{
> + pr_debug("%s: base %p mdev %d status %x\n",
> + __func__, base, mdev, __raw_readl(base + MBOX_MODE_REG(mdev)));
> +
> + return __raw_readl(base + MBOX_MODE_REG(mdev));
> +}
> +
> +static inline void __ipc_mode(void __iomem *base, unsigned int mode, int mdev)
> +{
> + pr_debug("%s: base %p mdev %d mode %u\n",
> + __func__, base, mdev, mode);
> +
> + __raw_writel(mode, base + MBOX_MODE_REG(mdev));
> +}
> +
> +static int _mdev_check_state_machine(struct hi3660_mbox_chan *mchan,
> + unsigned int state)
> +{
> + struct hi3660_mbox *mbox = mchan->parent;
> + int is_same = 0;
> +
> + if ((state & __ipc_status(mbox->base, mchan->slot)))
> + is_same = 1;
> +
> + pr_debug("%s: stm %u ch %d is_stm %d\n", __func__,
> + state, mchan->slot, is_same);
> +
> + return is_same;
> +}
> +
> +static void _mdev_release(struct hi3660_mbox_chan *mchan)
> +{
> + struct hi3660_mbox *mbox = mchan->parent;
> +
> + __ipc_cpu_imask_all(mbox->base, mchan->slot);
> + __ipc_set_src(mbox->base, mchan->ack_irq, mchan->slot);
> +
> + asm volatile ("sev");
> + return;
> +}
> +
> +static void _mdev_ensure_channel(struct hi3660_mbox_chan *mchan)
> +{
> + int timeout = 0, loop = 60 + 1000;
> +
> + if (_mdev_check_state_machine(mchan, MBOX_STATE_IDLE))
> + /*IDLE STATUS, return directly */
> + return;
> +
> + if (_mdev_check_state_machine(mchan, MBOX_STATE_ACK))
> + /*ACK STATUS, release the channel directly */
> + goto release;
> +
> + /*
> + * The worst situation is to delay:
> + * 1000 * 5us + 60 * 5ms = 305ms
> + */
> + while (timeout < loop) {
> +
> + if (timeout < 1000)
> + udelay(5);
> + else
> + usleep_range(3000, 5000);
> +
> + /* If the ack status is ready, bail out */
> + if (_mdev_check_state_machine(mchan, MBOX_STATE_ACK))
> + break;
> +
> + timeout++;
> + }
> +
> + if (unlikely(timeout == loop)) {
> + printk("\n %s ipc timeout...\n", __func__);
> +
> + /* TODO: add dump function */
> + }
> +
> +release:
> + /*release the channel */
> + _mdev_release(mchan);
> +}
> +
> +static int _mdev_unlock(struct hi3660_mbox_chan *mchan)
> +{
> + struct hi3660_mbox *mbox = mchan->parent;
> + int retry = 3;
> +
> + do {
> + __ipc_unlock(mbox->base, 0x1ACCE551);
> + if (MBOX_IPC_UNLOCKED == __ipc_lock_status(mbox->base))
> + break;
> +
> + udelay(10);
> + retry--;
> + } while (retry);
> +
> + if (!retry)
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int _mdev_occupy(struct hi3660_mbox_chan *mchan)
> +{
> + struct hi3660_mbox *mbox = mchan->parent;
> + unsigned int slot = mchan->slot;
> + int retry = 10;
> +
> + do {
> + /*
> + * hardware locking for exclusive accesing between
> + * CPUs without exclusive monitor mechanism.
> + */
> + if (!(__ipc_status(mbox->base, slot) & MBOX_STATE_IDLE))
> + __asm__ volatile ("wfe");
> + else {
> + /* Set the source processor bit */
> + __ipc_set_src(mbox->base, mchan->ack_irq, slot);
> + if (__ipc_read_src(mbox->base, slot) & BIT(mchan->ack_irq))
> + break;
> + }
> +
> + retry--;
> + /* Hardware unlock */
> + } while (retry);
> +
> + if (!retry)
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static bool hi3660_mbox_last_tx_done(struct mbox_chan *chan)
> +{
> + return 1;
> +}
> +
> +static int _mdev_hw_send(struct hi3660_mbox_chan *mchan, u32 *msg, u32 len)
> +{
> + struct hi3660_mbox *mbox = mchan->parent;
> + int i, ack_mode;
> + unsigned int temp;
> +
> + if (mchan->irq_mode)
> + ack_mode = MBOX_MANUAL_ACK;
> + else
> + ack_mode = MBOX_AUTO_ACK;
> +
> + /* interrupts unmask */
> + __ipc_cpu_imask_all(mbox->base, mchan->slot);
> +
> + if (MBOX_AUTO_ACK == ack_mode)
> + temp = BIT(mchan->dst_irq);
> + else
> + temp = BIT(mchan->ack_irq) | BIT(mchan->dst_irq);
> +
> + __ipc_cpu_imask_clr(mbox->base, temp, mchan->slot);
> +
> + /* des config */
> + __ipc_set_des(mbox->base, mchan->dst_irq, mchan->slot);
> +
> + /* ipc mode config */
> + if (MBOX_AUTO_ACK == ack_mode)
> + temp = AUTOMATIC_ACK_CONFIG;
> + else
> + temp = NO_FUNC_CONFIG;
> +
> + __ipc_mode(mbox->base, temp, mchan->slot);
> +
> + /* write data */
> + for (i = 0; i < len; i++)
> + __ipc_write(mbox->base, msg[i], mchan->slot, i);
> +
> + mchan->buf = msg;
> +
> + /* enable sending */
> + __ipc_send(mbox->base, BIT(mchan->ack_irq), mchan->slot);
> + return 0;
> +}
> +
> +static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
> +{
> + struct hi3660_mbox_chan *mchan = chan->con_priv;
> + int err = 0;
> +
> + /* indicate as a TX channel */
> + mchan->dir = MBOX_TX;
> +
> + _mdev_ensure_channel(mchan);
> +
Could you acquire the channel in startup() and release it in shutdown() ?

> + if (_mdev_unlock(mchan)) {
> + pr_err("%s: can not be unlocked\n", __func__);
> + err = -EIO;
> + goto out;
> + }
> +
> + if (_mdev_occupy(mchan)) {
> + pr_err("%s: can not be occupied\n", __func__);
> + err = -EBUSY;
> + goto out;
> + }
> +
> + _mdev_hw_send(mchan, msg, MBOX_MSG_LEN);
> +
> +out:
> + return err;
> +}
> +
> +static irqreturn_t hi3660_mbox_interrupt(int irq, void *p)
> +{
> + struct hi3660_mbox *mbox = p;
> + struct hi3660_mbox_chan *mchan;
> + struct mbox_chan *chan;
> + unsigned int state, intr_bit, i;
> + unsigned int status, imask, todo;
> + u32 msg[MBOX_MSG_LEN];
> +
> + state = __ipc_mbox_istatus(mbox->base, 0);
> +
> + if (!state) {
> + dev_warn(mbox->dev, "%s: spurious interrupt\n",
> + __func__);
> + return IRQ_HANDLED;
> + }
> +
> + while (state) {
> + intr_bit = __ffs(state);
> + state &= (state - 1);
> +
> + chan = mbox->irq_map_chan[intr_bit];
> + if (!chan) {
> + dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
> + __func__, intr_bit);
> + continue;
> + }
> +
> + mchan = chan->con_priv;
> +
> + for (i = 0; i < MBOX_MSG_LEN; i++)
> + mchan->buf[i] = __ipc_read(mbox->base, mchan->slot, i);
> +
> + if (mchan->dir == MBOX_TX)
> + mbox_chan_txdone(chan, 0);
> + else
> + mbox_chan_received_data(chan, (void *)msg);
> +
> + for (i = 0; i < MBOX_MSG_LEN; i++)
> + __ipc_write(mbox->base, 0x0, mchan->slot, i);
> +
> + imask = __ipc_cpu_imask_get(mbox->base, mchan->slot);
> + todo = ((1<<0) | (1<<1)) & (~imask);
> + __ipc_cpu_iclr(mbox->base, todo, mchan->slot);
> +
> +
> + status = __ipc_status(mbox->base, mchan->slot);
> + if ((MBOX_DESTINATION_STATUS & status) &&
> + (!(AUTOMATIC_ACK_CONFIG & status)))
> + __ipc_send(mbox->base, todo, mchan->slot);
> +
> + /*release the channel */
> + _mdev_release(mchan);
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int hi3660_mbox_startup(struct mbox_chan *chan)
> +{
> + struct hi3660_mbox_chan *mchan;
> +
> + mchan = chan->con_priv;
> +
> + if (mchan->irq_mode)
> + chan->txdone_method = TXDONE_BY_IRQ;
> +
No please. The core manages the txdone_method

> + return 0;
> +}
> +
> +static void hi3660_mbox_shutdown(struct mbox_chan *chan)
> +{
> + return;
> +}
> +
> +static struct mbox_chan_ops hi3660_mbox_ops = {
> + .send_data = hi3660_mbox_send_data,
> + .startup = hi3660_mbox_startup,
> + .shutdown = hi3660_mbox_shutdown,
> + .last_tx_done = hi3660_mbox_last_tx_done,
> +};
> +
> +static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
> + const struct of_phandle_args *spec)
> +{
> + struct hi3660_mbox *mbox = dev_get_drvdata(controller->dev);
> + struct hi3660_mbox_chan *mchan;
> + struct mbox_chan *chan;
> + unsigned int i = spec->args[0];
> + unsigned int dst_irq = spec->args[1];
> + unsigned int ack_irq = spec->args[2];
> +
> + /* Bounds checking */
> + if (i >= mbox->chan_num) {
> + dev_err(mbox->dev, "Invalid channel idx %d\n", i);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + /* Is requested channel free? */
> + chan = &mbox->chan[i];
> + if (mbox->irq_map_chan[i] == (void *)chan) {
> + dev_err(mbox->dev, "Channel in use\n");
> + return ERR_PTR(-EBUSY);
> + }
> +
> + mchan = chan->con_priv;
> + mchan->dst_irq = dst_irq;
> + mchan->ack_irq = ack_irq;
> +
> + mbox->irq_map_chan[i] = (void *)chan;
> + return chan;
> +}
> +
> +static const struct of_device_id hi3660_mbox_of_match[] = {
> + { .compatible = "hisilicon,hi3660-mbox", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
> +
> +static int hi3660_mbox_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct hi3660_mbox *mbox;
> + struct resource *res;
> + int i, err;
> +
> + mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
> + if (!mbox)
> + return -ENOMEM;
> +
> + mbox->dev = dev;
> + mbox->chan_num = MBOX_CHAN_MAX;
> + mbox->mchan = devm_kzalloc(dev,
> + mbox->chan_num * sizeof(*mbox->mchan), GFP_KERNEL);
> + if (!mbox->mchan)
> + return -ENOMEM;
> +
> + mbox->chan = devm_kzalloc(dev,
> + mbox->chan_num * sizeof(*mbox->chan), GFP_KERNEL);
> + if (!mbox->chan)
> + return -ENOMEM;
> +
> + mbox->irq = platform_get_irq(pdev, 0);
> + if (mbox->irq < 0)
> + return mbox->irq;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + mbox->base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(mbox->base)) {
> + dev_err(dev, "ioremap buffer failed\n");
> + return PTR_ERR(mbox->base);
> + }
> +
> + err = devm_request_irq(dev, mbox->irq, hi3660_mbox_interrupt, 0,
> + dev_name(dev), mbox);
> + if (err) {
> + dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
> + err);
> + return -ENODEV;
> + }
> +
> + mbox->controller.dev = dev;
> + mbox->controller.chans = &mbox->chan[0];
> + mbox->controller.num_chans = mbox->chan_num;
> + mbox->controller.ops = &hi3660_mbox_ops;
> + mbox->controller.of_xlate = hi3660_mbox_xlate;
> + mbox->controller.txdone_poll = true;
> + mbox->controller.txpoll_period = 5;
> +
> + for (i = 0; i < mbox->chan_num; i++) {
> + mbox->chan[i].con_priv = &mbox->mchan[i];
>
If you save 'i' in 'con_priv' here, you can avoid having 'slot' and
still get the mchan.

> + mbox->irq_map_chan[i] = NULL;
> +
> + mbox->mchan[i].parent = mbox;
> + mbox->mchan[i].slot = i;
> +
> + if (i == 28)
> + /* channel 28 is used for thermal with irq mode */
> + mbox->mchan[i].irq_mode = 1;
>
No please. Which client uses a channel, should not be hardcoded in the
driver. Get that from DT in xlate.

> + else
> + /* other channels use automatic mode */
> + mbox->mchan[i].irq_mode = 0;
> + }
> +
> + err = mbox_controller_register(&mbox->controller);
> + if (err) {
> + dev_err(dev, "Failed to register mailbox %d\n", err);
> + return err;
> + }
> +
> + platform_set_drvdata(pdev, mbox);
> + dev_info(dev, "Mailbox enabled\n");
> + return 0;
> +}
> +
> +static int hi3660_mbox_remove(struct platform_device *pdev)
> +{
> + struct hi3660_mbox *mbox = platform_get_drvdata(pdev);
> +
> + mbox_controller_unregister(&mbox->controller);
> + return 0;
> +}
> +
> +static struct platform_driver hi3660_mbox_driver = {
> + .driver = {
> + .name = "hi3660-mbox",
> + .owner = THIS_MODULE,
> + .of_match_table = hi3660_mbox_of_match,
> + },
> + .probe = hi3660_mbox_probe,
> + .remove = hi3660_mbox_remove,
> +};
> +
> +static int __init hi3660_mbox_init(void)
> +{
> + return platform_driver_register(&hi3660_mbox_driver);
> +}
> +core_initcall(hi3660_mbox_init);
> +
> +static void __exit hi3660_mbox_exit(void)
> +{
> + platform_driver_unregister(&hi3660_mbox_driver);
> +}
> +module_exit(hi3660_mbox_exit);
> +
> +MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
> +MODULE_DESCRIPTION("Hi3660 mailbox driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.8.3.2
>