Re: [PATCH v21 2/4] mailbox: mediatek: Add Mediatek CMDQ driver

houlong wei
2018-06-27T11:53:36Z

On Wed, 2018-02-21 at 11:53 +0800, CK Hu wrote:
> Hi, Houlong:
>
> I've one inline comment.
>
> On Wed, 2018-01-31 at 15:28 +0800, houlong.wei@mediatek.com wrote:
> > From: "hs.liao@mediatek.com" <hs.liao@mediatek.com>
> >
> > This patch is first version of Mediatek Command Queue(CMDQ) driver. The
> > CMDQ is used to help write registers with critical time limitation,
> > such as updating display configuration during the vblank. It controls
> > Global Command Engine (GCE) hardware to achieve this requirement.
> > Currently, CMDQ only supports display related hardwares, but we expect
> > it can be extended to other hardwares for future requirements.
> >
> > Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> > Signed-off-by: HS Liao <hs.liao@mediatek.com>
> > Signed-off-by: CK Hu <ck.hu@mediatek.com>
> > ---
> > drivers/mailbox/Kconfig | 10 +
> > drivers/mailbox/Makefile | 2 +
> > drivers/mailbox/mtk-cmdq-mailbox.c | 594 ++++++++++++++++++++++++++++++
> > include/linux/mailbox/mtk-cmdq-mailbox.h | 77 ++++
> > 4 files changed, 683 insertions(+)
> > create mode 100644 drivers/mailbox/mtk-cmdq-mailbox.c
> > create mode 100644 include/linux/mailbox/mtk-cmdq-mailbox.h
> >
> > diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> > index ba2f152..43bb26f 100644
> > --- a/drivers/mailbox/Kconfig
> > +++ b/drivers/mailbox/Kconfig
> > @@ -171,4 +171,14 @@ config BCM_FLEXRM_MBOX
> > Mailbox implementation of the Broadcom FlexRM ring manager,
> > which provides access to various offload engines on Broadcom
> > SoCs. Say Y here if you want to use the Broadcom FlexRM.
> > +
> > +config MTK_CMDQ_MBOX
> > + bool "MediaTek CMDQ Mailbox Support"
> > + depends on ARM64 && ( ARCH_MEDIATEK || COMPILE_TEST )
> > + select MTK_INFRACFG
> > + help
> > + Say yes here to add support for the MediaTek Command Queue (CMDQ)
> > + mailbox driver. The CMDQ is used to help read/write registers with
> > + critical time limitation, such as updating display configuration
> > + during the vblank.
> > endif
> > diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> > index 4896f8d..484d341 100644
> > --- a/drivers/mailbox/Makefile
> > +++ b/drivers/mailbox/Makefile
> > @@ -36,3 +36,5 @@ obj-$(CONFIG_BCM_FLEXRM_MBOX) += bcm-flexrm-mailbox.o
> > obj-$(CONFIG_QCOM_APCS_IPC) += qcom-apcs-ipc-mailbox.o
> >
> > obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
> > +
> > +obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
> > diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
> > new file mode 100644
> > index 0000000..394a335
> > --- /dev/null
> > +++ b/drivers/mailbox/mtk-cmdq-mailbox.c
> > @@ -0,0 +1,594 @@
> > +/*
> > + * Copyright (c) 2015 MediaTek Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * 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/clk.h>
> > +#include <linux/clk-provider.h>
> > +#include <linux/dma-mapping.h>
> > +#include <linux/errno.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/iopoll.h>
> > +#include <linux/kernel.h>
> > +#include <linux/mailbox_controller.h>
> > +#include <linux/mailbox/mtk-cmdq-mailbox.h>
> > +#include <linux/timer.h>
> > +
> > +#define CMDQ_THR_MAX_COUNT 16
> > +#define CMDQ_OP_CODE_MASK (0xff << CMDQ_OP_CODE_SHIFT)
> > +#define CMDQ_TIMEOUT_MS 1000
> > +#define CMDQ_IRQ_MASK 0xffff
> > +#define CMDQ_NUM_CMD(t) (t->cmd_buf_size / CMDQ_INST_SIZE)
> > +
> > +#define CMDQ_CURR_IRQ_STATUS 0x10
> > +#define CMDQ_THR_SLOT_CYCLES 0x30
> > +
> > +#define CMDQ_THR_BASE 0x100
> > +#define CMDQ_THR_SIZE 0x80
> > +#define CMDQ_THR_WARM_RESET 0x00
> > +#define CMDQ_THR_ENABLE_TASK 0x04
> > +#define CMDQ_THR_SUSPEND_TASK 0x08
> > +#define CMDQ_THR_CURR_STATUS 0x0c
> > +#define CMDQ_THR_IRQ_STATUS 0x10
> > +#define CMDQ_THR_IRQ_ENABLE 0x14
> > +#define CMDQ_THR_CURR_ADDR 0x20
> > +#define CMDQ_THR_END_ADDR 0x24
> > +#define CMDQ_THR_WAIT_TOKEN 0x30
> > +
> > +#define CMDQ_THR_ENABLED 0x1
> > +#define CMDQ_THR_DISABLED 0x0
> > +#define CMDQ_THR_SUSPEND 0x1
> > +#define CMDQ_THR_RESUME 0x0
> > +#define CMDQ_THR_STATUS_SUSPENDED BIT(1)
> > +#define CMDQ_THR_DO_WARM_RESET BIT(0)
> > +#define CMDQ_THR_ACTIVE_SLOT_CYCLES 0x3200
> > +#define CMDQ_THR_IRQ_DONE 0x1
> > +#define CMDQ_THR_IRQ_ERROR 0x12
> > +#define CMDQ_THR_IRQ_EN (CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
> > +#define CMDQ_THR_IS_WAITING BIT(31)
> > +
> > +#define CMDQ_JUMP_BY_OFFSET 0x10000000
> > +#define CMDQ_JUMP_BY_PA 0x10000001
> > +
> > +struct cmdq_thread {
> > + struct mbox_chan *chan;
> > + void __iomem *base;
> > + struct list_head task_busy_list;
> > + struct timer_list timeout;
> > + bool atomic_exec;
> > +};
> > +
> > +struct cmdq_task {
> > + struct cmdq *cmdq;
> > + struct list_head list_entry;
> > + dma_addr_t pa_base;
> > + struct cmdq_thread *thread;
> > + struct cmdq_pkt *pkt; /* the packet sent from mailbox client */
> > +};
> > +
> > +struct cmdq {
> > + struct mbox_controller mbox;
> > + void __iomem *base;
> > + u32 irq;
> > + struct cmdq_thread thread[CMDQ_THR_MAX_COUNT];
> > + struct clk *clock;
> > + bool suspended;
> > +};
> > +
> > +static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
> > +{
> > + u32 status;
> > +
> > + writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);
> > +
> > + /* If already disabled, treat as suspended successful. */
> > + if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
> > + return 0;
> > +
> > + if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
> > + status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
> > + dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
> > + (u32)(thread->base - cmdq->base));
> > + return -EFAULT;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static void cmdq_thread_resume(struct cmdq_thread *thread)
> > +{
> > + writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
> > +}
> > +
> > +static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
> > +{
> > + u32 warm_reset;
> > +
> > + writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
> > + if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
> > + warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
> > + 0, 10)) {
> > + dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
> > + (u32)(thread->base - cmdq->base));
> > + return -EFAULT;
> > + }
> > + writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
> > + return 0;
> > +}
> > +
> > +static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
> > +{
> > + cmdq_thread_reset(cmdq, thread);
> > + writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
> > +}
> > +
> > +/* notify GCE to re-fetch commands by setting GCE thread PC */
> > +static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
> > +{
> > + writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
> > + thread->base + CMDQ_THR_CURR_ADDR);
> > +}
> > +
> > +static void cmdq_task_insert_into_thread(struct cmdq_task *task)
> > +{
> > + struct device *dev = task->cmdq->mbox.dev;
> > + struct cmdq_thread *thread = task->thread;
> > + struct cmdq_task *prev_task = list_last_entry(
> > + &thread->task_busy_list, typeof(*task), list_entry);
> > + u64 *prev_task_base = prev_task->pkt->va_base;
> > +
> > + /* let previous task jump to this task */
> > + dma_sync_single_for_cpu(dev, prev_task->pa_base,
> > + prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
> > + prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
> > + (u64)CMDQ_JUMP_BY_PA << 32 | task->pa_base;
> > + dma_sync_single_for_device(dev, prev_task->pa_base,
> > + prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
> > +
> > + cmdq_thread_invalidate_fetched_data(thread);
> > +}
> > +
> > +static bool cmdq_command_is_wfe(u64 cmd)
> > +{
> > + u64 wfe_option = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
> > + u64 wfe_op = (u64)(CMDQ_CODE_WFE << CMDQ_OP_CODE_SHIFT) << 32;
> > + u64 wfe_mask = (u64)CMDQ_OP_CODE_MASK << 32 | 0xffffffff;
> > +
> > + return ((cmd & wfe_mask) == (wfe_op | wfe_option));
> > +}
> > +
> > +/* we assume tasks in the same display GCE thread are waiting the same event. */
> > +static void cmdq_task_remove_wfe(struct cmdq_task *task)
> > +{
> > + struct device *dev = task->cmdq->mbox.dev;
> > + u64 *base = task->pkt->va_base;
> > + int i;
> > +
> > + dma_sync_single_for_cpu(dev, task->pa_base, task->pkt->cmd_buf_size,
> > + DMA_TO_DEVICE);
> > + for (i = 0; i < CMDQ_NUM_CMD(task->pkt); i++)
> > + if (cmdq_command_is_wfe(base[i]))
> > + base[i] = (u64)CMDQ_JUMP_BY_OFFSET << 32 |
> > + CMDQ_JUMP_PASS;
> > + dma_sync_single_for_device(dev, task->pa_base, task->pkt->cmd_buf_size,
> > + DMA_TO_DEVICE);
> > +}
> > +
> > +static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
> > +{
> > + return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
> > +}
> > +
> > +static void cmdq_thread_wait_end(struct cmdq_thread *thread,
> > + unsigned long end_pa)
> > +{
> > + struct device *dev = thread->chan->mbox->dev;
> > + unsigned long curr_pa;
> > +
> > + if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_ADDR,
> > + curr_pa, curr_pa == end_pa, 1, 20))
> > + dev_err(dev, "GCE thread cannot run to end.\n");
> > +}
> > +
> > +static void cmdq_task_exec(struct cmdq_pkt *pkt, struct cmdq_thread *thread)
> > +{
> > + struct cmdq *cmdq;
> > + struct cmdq_task *task;
> > + unsigned long curr_pa, end_pa;
> > +
> > + cmdq = dev_get_drvdata(thread->chan->mbox->dev);
> > +
> > + /* Client should not flush new tasks if suspended. */
> > + WARN_ON(cmdq->suspended);
> > +
> > + task = kzalloc(sizeof(*task), GFP_ATOMIC);
> > + task->cmdq = cmdq;
> > + INIT_LIST_HEAD(&task->list_entry);
> > + task->pa_base = pkt->pa_base;
> > + task->thread = thread;
> > + task->pkt = pkt;
> > +
> > + if (list_empty(&thread->task_busy_list)) {
> > + WARN_ON(clk_enable(cmdq->clock) < 0);
> > + WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
> > +
> > + writel(task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
> > + writel(task->pa_base + pkt->cmd_buf_size,
> > + thread->base + CMDQ_THR_END_ADDR);
> > + writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
> > + writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
> > +
> > + mod_timer(&thread->timeout,
> > + jiffies + msecs_to_jiffies(CMDQ_TIMEOUT_MS));
> > + } else {
> > + WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
> > + curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
> > + end_pa = readl(thread->base + CMDQ_THR_END_ADDR);
> > +
> > + /*
> > + * Atomic execution should remove the following wfe, i.e. only
> > + * wait event at first task, and prevent to pause when running.
> > + */
> > + if (thread->atomic_exec) {
> > + /* GCE is executing if command is not WFE */
> > + if (!cmdq_thread_is_in_wfe(thread)) {
> > + cmdq_thread_resume(thread);
> > + cmdq_thread_wait_end(thread, end_pa);
> > + WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
> > + /* set to this task directly */
> > + writel(task->pa_base,
> > + thread->base + CMDQ_THR_CURR_ADDR);
> > + } else {
> > + cmdq_task_insert_into_thread(task);
> > + cmdq_task_remove_wfe(task);
> > + smp_mb(); /* modify jump before enable thread */
> > + }
> > + } else {
> > + /* check boundary */
> > + if (curr_pa == end_pa - CMDQ_INST_SIZE ||
> > + curr_pa == end_pa) {
> > + /* set to this task directly */
> > + writel(task->pa_base,
> > + thread->base + CMDQ_THR_CURR_ADDR);
> > + } else {
> > + cmdq_task_insert_into_thread(task);
> > + smp_mb(); /* modify jump before enable thread */
> > + }
> > + }
> > + writel(task->pa_base + pkt->cmd_buf_size,
> > + thread->base + CMDQ_THR_END_ADDR);
> > + cmdq_thread_resume(thread);
> > + }
> > + list_move_tail(&task->list_entry, &thread->task_busy_list);
>
> You implement a list to queue command because you need to execute
> multiple packet in the same vblank period. I've a suggestion that you
> need not to implement a list. Once cmdq driver receive two packet as
> below:
>
> Packet 1:
> (1) clear vblank event
> (2) wait vblank event
> (3) write register setting 1
> (4) no operation
>
> Packet 2:
> (1) clear vblank event
> (2) wait vblank event
> (3) write register setting 2
> (4) no operation
>
> In your current design, you modify these two packet as:
>
> Packet 1:
> (1) clear vblank event
> (2) wait vblank event
> (3) write register setting 1
> (4) Jump to packet 2 (modified)
>
> Packet 2:
> (1) no operation (modified)
> (2) no operation (modified)
> (3) write register setting 2
> (4) no operation
>
> So the register setting 1 and register setting 2 could be executed in
> the same vblank period.
>
> My suggestion is: when the client want to send packet 2, it 'abort'
> packet 1 at first. The 'abort' means remove it from channel. In current
> mailbox interface, mbox_free_channel() is most like abort function, but
> my abort would keep the channel. So maybe you need to implement a new
> mailbox interface which could remove packet in the channel. So the step
> would be:
>
> (1) Client generate packet 1 which include write register setting 1
> (2) Client send packet 1 to channel A
>
> When client want to send register setting 2,
>
> (3) Client abort channel A
> (4) Client generate packet 2 which include write register setting 1 & 2
> (5) Client send packet 2 to channel A
>
> Once you have the abort function, you could use the queue mechanism in
> mailbox core instead of implementing your own.
>
> For the client which have the atomic requirement, it also need not to
> implement a list to keep what command have not executed. So the abort
> interface would make client and controller much simpler.
>
> Regards,
> CK
>

Hi CK, thanks for you suggestion. Since current mailbox framework has
no 'abort' function and need add new interface. It may be complicated
to do this. Could we keep current solution?

> > +}
> > +
> > +static void cmdq_task_exec_done(struct cmdq_task *task, bool err)
> > +{
> > + struct device *dev = task->cmdq->mbox.dev;
> > + struct cmdq_cb_data cmdq_cb_data;
> > +
> > + dma_unmap_single(dev, task->pa_base, task->pkt->cmd_buf_size,
> > + DMA_TO_DEVICE);
> > + if (task->pkt->cb.cb) {
> > + cmdq_cb_data.err = err;
> > + cmdq_cb_data.data = task->pkt->cb.data;
> > + task->pkt->cb.cb(cmdq_cb_data);
> > + }
> > + list_del(&task->list_entry);
> > +}
> > +
> > +static void cmdq_task_handle_error(struct cmdq_task *task)
> > +{
> > + struct cmdq_thread *thread = task->thread;
> > + struct cmdq_task *next_task;
> > +
> > + dev_err(task->cmdq->mbox.dev, "task 0x%p error\n", task);
> > + WARN_ON(cmdq_thread_suspend(task->cmdq, thread) < 0);
> > + next_task = list_first_entry_or_null(&thread->task_busy_list,
> > + struct cmdq_task, list_entry);
> > + if (next_task)
> > + writel(next_task->pa_base, thread->base + CMDQ_THR_CURR_ADDR);
> > + cmdq_thread_resume(thread);
> > +}
> > +
> > +static void cmdq_thread_irq_handler(struct cmdq *cmdq,
> > + struct cmdq_thread *thread)
> > +{
> > + struct cmdq_task *task, *tmp, *curr_task = NULL;
> > + u32 curr_pa, irq_flag, task_end_pa;
> > + bool err;
> > +
> > + irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
> > + writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);
> > +
> > + /*
> > + * When ISR call this function, another CPU core could run
> > + * "release task" right before we acquire the spin lock, and thus
> > + * reset / disable this GCE thread, so we need to check the enable
> > + * bit of this GCE thread.
> > + */
> > + if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
> > + return;
> > +
> > + if (irq_flag & CMDQ_THR_IRQ_ERROR)
> > + err = true;
> > + else if (irq_flag & CMDQ_THR_IRQ_DONE)
> > + err = false;
> > + else
> > + return;
> > +
> > + curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR);
> > +
> > + list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
> > + list_entry) {
> > + task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
> > + if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
> > + curr_task = task;
> > +
> > + if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
> > + cmdq_task_exec_done(task, false);
> > + kfree(task);
> > + } else if (err) {
> > + cmdq_task_exec_done(task, true);
> > + cmdq_task_handle_error(curr_task);
> > + kfree(task);
> > + }
> > +
> > + if (curr_task)
> > + break;
> > + }
> > +
> > + if (list_empty(&thread->task_busy_list)) {
> > + cmdq_thread_disable(cmdq, thread);
> > + clk_disable(cmdq->clock);
> > + } else {
> > + mod_timer(&thread->timeout,
> > + jiffies + msecs_to_jiffies(CMDQ_TIMEOUT_MS));
> > + }
> > +}
> > +
> > +static irqreturn_t cmdq_irq_handler(int irq, void *dev)
> > +{
> > + struct cmdq *cmdq = dev;
> > + unsigned long irq_status, flags = 0L;
> > + int bit;
> > +
> > + irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & CMDQ_IRQ_MASK;
> > + if (!(irq_status ^ CMDQ_IRQ_MASK))
> > + return IRQ_NONE;
> > +
> > + for_each_clear_bit(bit, &irq_status, fls(CMDQ_IRQ_MASK)) {
> > + struct cmdq_thread *thread = &cmdq->thread[bit];
> > +
> > + spin_lock_irqsave(&thread->chan->lock, flags);
> > + cmdq_thread_irq_handler(cmdq, thread);
> > + spin_unlock_irqrestore(&thread->chan->lock, flags);
> > + }
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static void cmdq_thread_handle_timeout(struct timer_list *t)
> > +{
> > + struct cmdq_thread *thread = from_timer(thread, t, timeout);
> > + struct cmdq *cmdq = container_of(thread->chan->mbox, struct cmdq, mbox);
> > + struct cmdq_task *task, *tmp;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&thread->chan->lock, flags);
> > + WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
> > +
> > + /*
> > + * Although IRQ is disabled, GCE continues to execute.
> > + * It may have pending IRQ before GCE thread is suspended,
> > + * so check this condition again.
> > + */
> > + cmdq_thread_irq_handler(cmdq, thread);
> > +
> > + if (list_empty(&thread->task_busy_list)) {
> > + cmdq_thread_resume(thread);
> > + spin_unlock_irqrestore(&thread->chan->lock, flags);
> > + return;
> > + }
> > +
> > + dev_err(cmdq->mbox.dev, "timeout\n");
> > + list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
> > + list_entry) {
> > + cmdq_task_exec_done(task, true);
> > + kfree(task);
> > + }
> > +
> > + cmdq_thread_resume(thread);
> > + cmdq_thread_disable(cmdq, thread);
> > + clk_disable(cmdq->clock);
> > + spin_unlock_irqrestore(&thread->chan->lock, flags);
> > +}
> > +
> > +static int cmdq_suspend(struct device *dev)
> > +{
> > + struct cmdq *cmdq = dev_get_drvdata(dev);
> > + struct cmdq_thread *thread;
> > + int i;
> > + bool task_running = false;
> > +
> > + cmdq->suspended = true;
> > +
> > + for (i = 0; i < ARRAY_SIZE(cmdq->thread); i++) {
> > + thread = &cmdq->thread[i];
> > + if (!list_empty(&thread->task_busy_list)) {
> > + task_running = true;
> > + break;
> > + }
> > + }
> > +
> > + if (task_running)
> > + dev_warn(dev, "exist running task(s) in suspend\n");
> > +
> > + clk_unprepare(cmdq->clock);
> > + return 0;
> > +}
> > +
> > +static int cmdq_resume(struct device *dev)
> > +{
> > + struct cmdq *cmdq = dev_get_drvdata(dev);
> > +
> > + WARN_ON(clk_prepare(cmdq->clock) < 0);
> > + cmdq->suspended = false;
> > + return 0;
> > +}
> > +
> > +static int cmdq_remove(struct platform_device *pdev)
> > +{
> > + struct cmdq *cmdq = platform_get_drvdata(pdev);
> > +
> > + mbox_controller_unregister(&cmdq->mbox);
> > + clk_unprepare(cmdq->clock);
> > + return 0;
> > +}
> > +
> > +static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
> > +{
> > + cmdq_task_exec(data, chan->con_priv);
> > + return 0;
> > +}
> > +
> > +static int cmdq_mbox_startup(struct mbox_chan *chan)
> > +{
> > + return 0;
> > +}
> > +
> > +static void cmdq_mbox_shutdown(struct mbox_chan *chan)
> > +{
> > +}
> > +
> > +static bool cmdq_mbox_last_tx_done(struct mbox_chan *chan)
> > +{
> > + return true;
> > +}
> > +
> > +static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
> > + .send_data = cmdq_mbox_send_data,
> > + .startup = cmdq_mbox_startup,
> > + .shutdown = cmdq_mbox_shutdown,
> > + .last_tx_done = cmdq_mbox_last_tx_done,
> > +};
> > +
> > +static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
> > + const struct of_phandle_args *sp)
> > +{
> > + int ind = sp->args[0];
> > + struct cmdq_thread *thread;
> > +
> > + if (ind >= mbox->num_chans)
> > + return ERR_PTR(-EINVAL);
> > +
> > + thread = mbox->chans[ind].con_priv;
> > + thread->atomic_exec = (sp->args[1] != 0);
> > + thread->chan = &mbox->chans[ind];
> > +
> > + return &mbox->chans[ind];
> > +}
> > +
> > +static int cmdq_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct resource *res;
> > + struct cmdq *cmdq;
> > + int err, i;
> > +
> > + cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
> > + if (!cmdq)
> > + return -ENOMEM;
> > +
> > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + cmdq->base = devm_ioremap_resource(dev, res);
> > + if (IS_ERR(cmdq->base)) {
> > + dev_err(dev, "failed to ioremap gce\n");
> > + return PTR_ERR(cmdq->base);
> > + }
> > +
> > + cmdq->irq = platform_get_irq(pdev, 0);
> > + if (!cmdq->irq) {
> > + dev_err(dev, "failed to get irq\n");
> > + return -EINVAL;
> > + }
> > + err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
> > + "mtk_cmdq", cmdq);
> > + if (err < 0) {
> > + dev_err(dev, "failed to register ISR (%d)\n", err);
> > + return err;
> > + }
> > +
> > + dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
> > + dev, cmdq->base, cmdq->irq);
> > +
> > + cmdq->clock = devm_clk_get(dev, "gce");
> > + if (IS_ERR(cmdq->clock)) {
> > + dev_err(dev, "failed to get gce clk\n");
> > + return PTR_ERR(cmdq->clock);
> > + }
> > +
> > + cmdq->mbox.dev = dev;
> > + cmdq->mbox.chans = devm_kcalloc(dev, CMDQ_THR_MAX_COUNT,
> > + sizeof(*cmdq->mbox.chans), GFP_KERNEL);
> > + if (!cmdq->mbox.chans)
> > + return -ENOMEM;
> > +
> > + cmdq->mbox.num_chans = CMDQ_THR_MAX_COUNT;
> > + cmdq->mbox.ops = &cmdq_mbox_chan_ops;
> > + cmdq->mbox.of_xlate = cmdq_xlate;
> > +
> > + /* make use of TXDONE_BY_ACK */
> > + cmdq->mbox.txdone_irq = false;
> > + cmdq->mbox.txdone_poll = false;
> > +
> > + for (i = 0; i < ARRAY_SIZE(cmdq->thread); i++) {
> > + cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
> > + CMDQ_THR_SIZE * i;
> > + INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
> > + timer_setup(&cmdq->thread[i].timeout,
> > + cmdq_thread_handle_timeout, 0);
> > + cmdq->mbox.chans[i].con_priv = &cmdq->thread[i];
> > + }
> > +
> > + err = mbox_controller_register(&cmdq->mbox);
> > + if (err < 0) {
> > + dev_err(dev, "failed to register mailbox: %d\n", err);
> > + return err;
> > + }
> > +
> > + platform_set_drvdata(pdev, cmdq);
> > + WARN_ON(clk_prepare(cmdq->clock) < 0);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct dev_pm_ops cmdq_pm_ops = {
> > + .suspend = cmdq_suspend,
> > + .resume = cmdq_resume,
> > +};
> > +
> > +static const struct of_device_id cmdq_of_ids[] = {
> > + {.compatible = "mediatek,mt8173-gce",},
> > + {}
> > +};
> > +
> > +static struct platform_driver cmdq_drv = {
> > + .probe = cmdq_probe,
> > + .remove = cmdq_remove,
> > + .driver = {
> > + .name = "mtk_cmdq",
> > + .pm = &cmdq_pm_ops,
> > + .of_match_table = cmdq_of_ids,
> > + }
> > +};
> > +
> > +builtin_platform_driver(cmdq_drv);
> > diff --git a/include/linux/mailbox/mtk-cmdq-mailbox.h b/include/linux/mailbox/mtk-cmdq-mailbox.h
> > new file mode 100644
> > index 0000000..c463f2f
> > --- /dev/null
> > +++ b/include/linux/mailbox/mtk-cmdq-mailbox.h
> > @@ -0,0 +1,77 @@
> > +/*
> > + * Copyright (c) 2015 MediaTek Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + *
> > + * 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.
> > + */
> > +
> > +#ifndef __MTK_CMDQ_MAILBOX_H__
> > +#define __MTK_CMDQ_MAILBOX_H__
> > +
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/types.h>
> > +
> > +#define CMDQ_INST_SIZE 8 /* instruction is 64-bit */
> > +#define CMDQ_SUBSYS_SHIFT 16
> > +#define CMDQ_OP_CODE_SHIFT 24
> > +#define CMDQ_JUMP_PASS CMDQ_INST_SIZE
> > +
> > +#define CMDQ_WFE_UPDATE BIT(31)
> > +#define CMDQ_WFE_WAIT BIT(15)
> > +#define CMDQ_WFE_WAIT_VALUE 0x1
> > +
> > +/*
> > + * CMDQ_CODE_MASK:
> > + * set write mask
> > + * format: op mask
> > + * CMDQ_CODE_WRITE:
> > + * write value into target register
> > + * format: op subsys address value
> > + * CMDQ_CODE_JUMP:
> > + * jump by offset
> > + * format: op offset
> > + * CMDQ_CODE_WFE:
> > + * wait for event and clear
> > + * it is just clear if no wait
> > + * format: [wait] op event update:1 to_wait:1 wait:1
> > + * [clear] op event update:1 to_wait:0 wait:0
> > + * CMDQ_CODE_EOC:
> > + * end of command
> > + * format: op irq_flag
> > + */
> > +enum cmdq_code {
> > + CMDQ_CODE_MASK = 0x02,
> > + CMDQ_CODE_WRITE = 0x04,
> > + CMDQ_CODE_JUMP = 0x10,
> > + CMDQ_CODE_WFE = 0x20,
> > + CMDQ_CODE_EOC = 0x40,
> > +};
> > +
> > +struct cmdq_cb_data {
> > + bool err;
> > + void *data;
> > +};
> > +
> > +typedef void (*cmdq_async_flush_cb)(struct cmdq_cb_data data);
> > +
> > +struct cmdq_task_cb {
> > + cmdq_async_flush_cb cb;
> > + void *data;
> > +};
> > +
> > +struct cmdq_pkt {
> > + void *va_base;
> > + dma_addr_t pa_base;
> > + size_t cmd_buf_size; /* command occupied size */
> > + size_t buf_size; /* real buffer size */
> > + struct cmdq_task_cb cb;
> > +};
> > +
> > +#endif /* __MTK_CMDQ_MAILBOX_H__ */
>
>