drivers/mailbox/mtk-cmdq-mailbox.c

// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2018 MediaTek Inc.

#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/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sizes.h>
#include <linux/mailbox_controller.h>
#include <linux/mailbox/mtk-cmdq-mailbox.h>
#include <linux/of.h>

#define CMDQ_MBOX_AUTOSUSPEND_DELAY_MS	100

#define CMDQ_OP_CODE_MASK		(0xff << CMDQ_OP_CODE_SHIFT)
#define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)

#define CMDQ_CURR_IRQ_STATUS		0x10
#define CMDQ_SYNC_TOKEN_UPDATE		0x68
#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_PRIORITY		0x40

#define GCE_GCTL_VALUE			0x48
#define GCE_CTRL_BY_SW				GENMASK(2, 0)
#define GCE_DDR_EN				GENMASK(18, 16)

#define GCE_VM_ID_MAP(n)		(0x5018 + (n) / 10 * 4)
#define GCE_VM_ID_MAP_THR_FLD_SHIFT(n)		((n) % 10 * 3)
#define GCE_VM_ID_MAP_HOST_VM			GENMASK(2, 0)
#define GCE_VM_CPR_GSIZE		0x50c4
#define GCE_VM_CPR_GSIZE_FLD_SHIFT(vm_id)	((vm_id) * 4)
#define GCE_VM_CPR_GSIZE_MAX			GENMASK(3, 0)

#define CMDQ_THR_ACTIVE_SLOT_CYCLES	0x3200
#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_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;
	u32			priority;
};

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;
	int			irq;
	u32			irq_mask;
	const struct gce_plat	*pdata;
	struct cmdq_thread	*thread;
	struct clk_bulk_data	*clocks;
	bool			suspended;
};

struct gce_plat {
	u32 thread_nr;
	u8 shift;
	dma_addr_t mminfra_offset;
	bool control_by_sw;
	bool sw_ddr_en;
	bool gce_vm;
	u32 gce_num;
};

static inline u32 cmdq_convert_gce_addr(dma_addr_t addr, const struct gce_plat *pdata)
{
	/* Convert DMA addr (PA or IOVA) to GCE readable addr */
	return (addr + pdata->mminfra_offset) >> pdata->shift;
}

static inline dma_addr_t cmdq_revert_gce_addr(u32 addr, const struct gce_plat *pdata)
{
	/* Revert GCE readable addr to DMA addr (PA or IOVA) */
	return ((dma_addr_t)addr << pdata->shift) - pdata->mminfra_offset;
}

void cmdq_get_mbox_priv(struct mbox_chan *chan, struct cmdq_mbox_priv *priv)
{
	struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);

	priv->shift_pa = cmdq->pdata->shift;
	priv->mminfra_offset = cmdq->pdata->mminfra_offset;
}
EXPORT_SYMBOL(cmdq_get_mbox_priv);

u8 cmdq_get_shift_pa(struct mbox_chan *chan)
{
	struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);

	return cmdq->pdata->shift;
}
EXPORT_SYMBOL(cmdq_get_shift_pa);

static void cmdq_vm_init(struct cmdq *cmdq)
{
	int i;
	u32 vm_cpr_gsize = 0, vm_id_map = 0;
	u32 *vm_map = NULL;

	if (!cmdq->pdata->gce_vm)
		return;

	vm_map = kcalloc(cmdq->pdata->thread_nr, sizeof(*vm_map), GFP_KERNEL);
	if (!vm_map)
		return;

	/* only configure the max CPR SRAM size to host vm (vm_id = 0) currently */
	vm_cpr_gsize = GCE_VM_CPR_GSIZE_MAX << GCE_VM_CPR_GSIZE_FLD_SHIFT(0);

	/* set all thread mapping to host vm currently */
	for (i = 0; i < cmdq->pdata->thread_nr; i++)
		vm_map[i] = GCE_VM_ID_MAP_HOST_VM << GCE_VM_ID_MAP_THR_FLD_SHIFT(i);

	/* set the amount of CPR SRAM to allocate to each VM */
	writel(vm_cpr_gsize, cmdq->base + GCE_VM_CPR_GSIZE);

	/* config CPR_GSIZE before setting VM_ID_MAP to avoid data leakage */
	for (i = 0; i < cmdq->pdata->thread_nr; i++) {
		vm_id_map |= vm_map[i];
		/* config every 10 threads, e.g., thread id=0~9, 10~19, ..., into one register */
		if ((i + 1) % 10 == 0) {
			writel(vm_id_map, cmdq->base + GCE_VM_ID_MAP(i));
			vm_id_map = 0;
		}
	}
	/* config remaining threads settings */
	if (cmdq->pdata->thread_nr % 10 != 0)
		writel(vm_id_map, cmdq->base + GCE_VM_ID_MAP(cmdq->pdata->thread_nr - 1));

	kfree(vm_map);
}

static void cmdq_gctl_value_toggle(struct cmdq *cmdq, bool ddr_enable)
{
	u32 val = cmdq->pdata->control_by_sw ? GCE_CTRL_BY_SW : 0;

	if (!cmdq->pdata->control_by_sw && !cmdq->pdata->sw_ddr_en)
		return;

	if (cmdq->pdata->sw_ddr_en && ddr_enable)
		val |= GCE_DDR_EN;

	writel(val, cmdq->base + GCE_GCTL_VALUE);
}

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 void cmdq_init(struct cmdq *cmdq)
{
	int i;

	WARN_ON(clk_bulk_enable(cmdq->pdata->gce_num, cmdq->clocks));

	cmdq_vm_init(cmdq);
	cmdq_gctl_value_toggle(cmdq, true);

	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
	clk_bulk_disable(cmdq->pdata->gce_num, cmdq->clocks);
}

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;
	}

	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;
	u32 gce_addr = cmdq_convert_gce_addr(task->pa_base, task->cmdq->pdata);

	/* 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 | gce_addr;
	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_thread_is_in_wfe(struct cmdq_thread *thread)
{
	return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
}

static void cmdq_task_exec_done(struct cmdq_task *task, int sta)
{
	struct cmdq_cb_data data;

	data.sta = sta;
	data.pkt = task->pkt;
	mbox_chan_received_data(task->thread->chan, &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;
	struct cmdq *cmdq = task->cmdq;

	dev_err(cmdq->mbox.dev, "task 0x%p error\n", task);
	WARN_ON(cmdq_thread_suspend(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 >> cmdq->pdata->shift,
		       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 irq_flag, gce_addr;
	dma_addr_t curr_pa, 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;

	gce_addr = readl(thread->base + CMDQ_THR_CURR_ADDR);
	curr_pa = cmdq_revert_gce_addr(gce_addr, cmdq->pdata);

	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, 0);
			kfree(task);
		} else if (err) {
			cmdq_task_exec_done(task, -ENOEXEC);
			cmdq_task_handle_error(curr_task);
			kfree(task);
		}

		if (curr_task)
			break;
	}

	if (list_empty(&thread->task_busy_list))
		cmdq_thread_disable(cmdq, thread);
}

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, cmdq->pdata->thread_nr) {
		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);
	}

	pm_runtime_mark_last_busy(cmdq->mbox.dev);

	return IRQ_HANDLED;
}

static int cmdq_runtime_resume(struct device *dev)
{
	struct cmdq *cmdq = dev_get_drvdata(dev);
	int ret;

	ret = clk_bulk_enable(cmdq->pdata->gce_num, cmdq->clocks);
	if (ret)
		return ret;

	cmdq_gctl_value_toggle(cmdq, true);
	return 0;
}

static int cmdq_runtime_suspend(struct device *dev)
{
	struct cmdq *cmdq = dev_get_drvdata(dev);

	cmdq_gctl_value_toggle(cmdq, false);
	clk_bulk_disable(cmdq->pdata->gce_num, cmdq->clocks);
	return 0;
}

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 < cmdq->pdata->thread_nr; 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");

	return pm_runtime_force_suspend(dev);
}

static int cmdq_resume(struct device *dev)
{
	struct cmdq *cmdq = dev_get_drvdata(dev);

	WARN_ON(pm_runtime_force_resume(dev));
	cmdq->suspended = false;

	return 0;
}

static void cmdq_remove(struct platform_device *pdev)
{
	struct cmdq *cmdq = platform_get_drvdata(pdev);

	if (!IS_ENABLED(CONFIG_PM))
		cmdq_runtime_suspend(&pdev->dev);

	clk_bulk_unprepare(cmdq->pdata->gce_num, cmdq->clocks);
}

static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
{
	struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
	struct cmdq_task *task;
	u32 gce_addr;
	dma_addr_t curr_pa, end_pa;

	/* Client should not flush new tasks if suspended. */
	WARN_ON(cmdq->suspended);

	task = kzalloc_obj(*task, GFP_ATOMIC);
	if (!task)
		return -ENOMEM;

	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)) {
		/*
		 * The thread reset will clear thread related register to 0,
		 * including pc, end, priority, irq, suspend and enable. Thus
		 * set CMDQ_THR_ENABLED to CMDQ_THR_ENABLE_TASK will enable
		 * thread and make it running.
		 */
		WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);

		gce_addr = cmdq_convert_gce_addr(task->pa_base, cmdq->pdata);
		writel(gce_addr, thread->base + CMDQ_THR_CURR_ADDR);
		gce_addr = cmdq_convert_gce_addr(task->pa_base + pkt->cmd_buf_size, cmdq->pdata);
		writel(gce_addr, thread->base + CMDQ_THR_END_ADDR);

		writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
		writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
		writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
	} else {
		WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
		gce_addr = readl(thread->base + CMDQ_THR_CURR_ADDR);
		curr_pa = cmdq_revert_gce_addr(gce_addr, cmdq->pdata);
		gce_addr = readl(thread->base + CMDQ_THR_END_ADDR);
		end_pa = cmdq_revert_gce_addr(gce_addr, cmdq->pdata);
		/* check boundary */
		if (curr_pa == end_pa - CMDQ_INST_SIZE ||
		    curr_pa == end_pa) {
			/* set to this task directly */
			gce_addr = cmdq_convert_gce_addr(task->pa_base, cmdq->pdata);
			writel(gce_addr, thread->base + CMDQ_THR_CURR_ADDR);
		} else {
			cmdq_task_insert_into_thread(task);
			smp_mb(); /* modify jump before enable thread */
		}
		gce_addr = cmdq_convert_gce_addr(task->pa_base + pkt->cmd_buf_size, cmdq->pdata);
		writel(gce_addr, thread->base + CMDQ_THR_END_ADDR);
		cmdq_thread_resume(thread);
	}
	list_move_tail(&task->list_entry, &thread->task_busy_list);

	return 0;
}

static int cmdq_mbox_startup(struct mbox_chan *chan)
{
	return 0;
}

static void cmdq_mbox_shutdown(struct mbox_chan *chan)
{
	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
	struct cmdq_task *task, *tmp;
	unsigned long flags;

	WARN_ON(pm_runtime_get_sync(cmdq->mbox.dev) < 0);

	spin_lock_irqsave(&thread->chan->lock, flags);
	if (list_empty(&thread->task_busy_list))
		goto done;

	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);

	/* make sure executed tasks have success callback */
	cmdq_thread_irq_handler(cmdq, thread);
	if (list_empty(&thread->task_busy_list))
		goto done;

	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
				 list_entry) {
		cmdq_task_exec_done(task, -ECONNABORTED);
		kfree(task);
	}

	cmdq_thread_disable(cmdq, thread);

done:
	/*
	 * The thread->task_busy_list empty means thread already disable. The
	 * cmdq_mbox_send_data() always reset thread which clear disable and
	 * suspend statue when first pkt send to channel, so there is no need
	 * to do any operation here, only unlock and leave.
	 */
	spin_unlock_irqrestore(&thread->chan->lock, flags);

	pm_runtime_mark_last_busy(cmdq->mbox.dev);
	pm_runtime_put_autosuspend(cmdq->mbox.dev);
}

static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
{
	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
	struct cmdq_cb_data data;
	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
	struct cmdq_task *task, *tmp;
	unsigned long flags;
	u32 enable;
	int ret;

	ret = pm_runtime_get_sync(cmdq->mbox.dev);
	if (ret < 0)
		return ret;

	spin_lock_irqsave(&thread->chan->lock, flags);
	if (list_empty(&thread->task_busy_list))
		goto out;

	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
	if (!cmdq_thread_is_in_wfe(thread))
		goto wait;

	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
				 list_entry) {
		data.sta = -ECONNABORTED;
		data.pkt = task->pkt;
		mbox_chan_received_data(task->thread->chan, &data);
		list_del(&task->list_entry);
		kfree(task);
	}

	cmdq_thread_resume(thread);
	cmdq_thread_disable(cmdq, thread);

out:
	spin_unlock_irqrestore(&thread->chan->lock, flags);
	pm_runtime_mark_last_busy(cmdq->mbox.dev);
	pm_runtime_put_autosuspend(cmdq->mbox.dev);

	return 0;

wait:
	cmdq_thread_resume(thread);
	spin_unlock_irqrestore(&thread->chan->lock, flags);
	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
				      enable, enable == 0, 1, timeout)) {
		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
			(u32)(thread->base - cmdq->base));

		return -EFAULT;
	}
	pm_runtime_mark_last_busy(cmdq->mbox.dev);
	pm_runtime_put_autosuspend(cmdq->mbox.dev);
	return 0;
}

static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
	.send_data = cmdq_mbox_send_data,
	.startup = cmdq_mbox_startup,
	.shutdown = cmdq_mbox_shutdown,
	.flush = cmdq_mbox_flush,
};

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 = (struct cmdq_thread *)mbox->chans[ind].con_priv;
	thread->priority = sp->args[1];
	thread->chan = &mbox->chans[ind];

	return &mbox->chans[ind];
}

static int cmdq_get_clocks(struct device *dev, struct cmdq *cmdq)
{
	static const char * const gce_name = "gce";
	struct device_node *parent = dev->of_node->parent;
	struct clk_bulk_data *clks;

	cmdq->clocks = devm_kcalloc(dev, cmdq->pdata->gce_num,
				    sizeof(*cmdq->clocks), GFP_KERNEL);
	if (!cmdq->clocks)
		return -ENOMEM;

	if (cmdq->pdata->gce_num == 1) {
		clks = &cmdq->clocks[0];

		clks->id = gce_name;
		clks->clk = devm_clk_get(dev, NULL);
		if (IS_ERR(clks->clk))
			return dev_err_probe(dev, PTR_ERR(clks->clk),
					     "failed to get gce clock\n");

		return 0;
	}

	/*
	 * If there is more than one GCE, get the clocks for the others too,
	 * as the clock of the main GCE must be enabled for additional IPs
	 * to be reachable.
	 */
	for_each_child_of_node_scoped(parent, node) {
		int alias_id = of_alias_get_id(node, gce_name);

		if (alias_id < 0 || alias_id >= cmdq->pdata->gce_num)
			continue;

		clks = &cmdq->clocks[alias_id];

		clks->id = devm_kasprintf(dev, GFP_KERNEL, "gce%d", alias_id);
		if (!clks->id)
			return -ENOMEM;

		clks->clk = of_clk_get(node, 0);
		if (IS_ERR(clks->clk))
			return dev_err_probe(dev, PTR_ERR(clks->clk),
					     "failed to get gce%d clock\n", alias_id);
	}

	return 0;
}

static int cmdq_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct cmdq *cmdq;
	int err, i;

	cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
	if (!cmdq)
		return -ENOMEM;

	cmdq->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(cmdq->base))
		return PTR_ERR(cmdq->base);

	cmdq->irq = platform_get_irq(pdev, 0);
	if (cmdq->irq < 0)
		return cmdq->irq;

	cmdq->pdata = device_get_match_data(dev);
	if (!cmdq->pdata) {
		dev_err(dev, "failed to get match data\n");
		return -EINVAL;
	}

	cmdq->irq_mask = GENMASK(cmdq->pdata->thread_nr - 1, 0);

	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
		dev, cmdq->base, cmdq->irq);

	err = cmdq_get_clocks(dev, cmdq);
	if (err)
		return err;

	dma_set_coherent_mask(dev,
			      DMA_BIT_MASK(sizeof(u32) * BITS_PER_BYTE + cmdq->pdata->shift));

	cmdq->mbox.dev = dev;
	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->pdata->thread_nr,
					sizeof(*cmdq->mbox.chans), GFP_KERNEL);
	if (!cmdq->mbox.chans)
		return -ENOMEM;

	cmdq->mbox.num_chans = cmdq->pdata->thread_nr;
	cmdq->mbox.ops = &cmdq_mbox_chan_ops;
	cmdq->mbox.of_xlate = cmdq_xlate;

	/* make use of MBOX_TXDONE_BY_ACK */
	cmdq->mbox.txdone_irq = false;
	cmdq->mbox.txdone_poll = false;

	cmdq->thread = devm_kcalloc(dev, cmdq->pdata->thread_nr,
					sizeof(*cmdq->thread), GFP_KERNEL);
	if (!cmdq->thread)
		return -ENOMEM;

	for (i = 0; i < cmdq->pdata->thread_nr; i++) {
		cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
				CMDQ_THR_SIZE * i;
		INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
		cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
	}

	platform_set_drvdata(pdev, cmdq);

	WARN_ON(clk_bulk_prepare(cmdq->pdata->gce_num, cmdq->clocks));

	cmdq_init(cmdq);

	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;
	}

	/* If Runtime PM is not available enable the clocks now. */
	if (!IS_ENABLED(CONFIG_PM)) {
		err = cmdq_runtime_resume(dev);
		if (err)
			return err;
	}

	err = devm_pm_runtime_enable(dev);
	if (err)
		return err;

	pm_runtime_set_autosuspend_delay(dev, CMDQ_MBOX_AUTOSUSPEND_DELAY_MS);
	pm_runtime_use_autosuspend(dev);

	err = devm_mbox_controller_register(dev, &cmdq->mbox);
	if (err < 0) {
		dev_err(dev, "failed to register mailbox: %d\n", err);
		return err;
	}

	return 0;
}

static const struct dev_pm_ops cmdq_pm_ops = {
	.suspend = cmdq_suspend,
	.resume = cmdq_resume,
	SET_RUNTIME_PM_OPS(cmdq_runtime_suspend,
			   cmdq_runtime_resume, NULL)
};

static const struct gce_plat gce_plat_mt6779 = {
	.thread_nr = 24,
	.shift = 3,
	.control_by_sw = false,
	.gce_num = 1
};

static const struct gce_plat gce_plat_mt8173 = {
	.thread_nr = 16,
	.shift = 0,
	.control_by_sw = false,
	.gce_num = 1
};

static const struct gce_plat gce_plat_mt8183 = {
	.thread_nr = 24,
	.shift = 0,
	.control_by_sw = false,
	.gce_num = 1
};

static const struct gce_plat gce_plat_mt8186 = {
	.thread_nr = 24,
	.shift = 3,
	.control_by_sw = true,
	.sw_ddr_en = true,
	.gce_num = 1
};

static const struct gce_plat gce_plat_mt8188 = {
	.thread_nr = 32,
	.shift = 3,
	.control_by_sw = true,
	.gce_num = 2
};

static const struct gce_plat gce_plat_mt8192 = {
	.thread_nr = 24,
	.shift = 3,
	.control_by_sw = true,
	.gce_num = 1
};

static const struct gce_plat gce_plat_mt8195 = {
	.thread_nr = 24,
	.shift = 3,
	.control_by_sw = true,
	.gce_num = 2
};

static const struct gce_plat gce_plat_mt8196 = {
	.thread_nr = 32,
	.shift = 3,
	.mminfra_offset = SZ_2G,
	.control_by_sw = true,
	.sw_ddr_en = true,
	.gce_vm = true,
	.gce_num = 2
};

static const struct of_device_id cmdq_of_ids[] = {
	{.compatible = "mediatek,mt6779-gce", .data = (void *)&gce_plat_mt6779},
	{.compatible = "mediatek,mt8173-gce", .data = (void *)&gce_plat_mt8173},
	{.compatible = "mediatek,mt8183-gce", .data = (void *)&gce_plat_mt8183},
	{.compatible = "mediatek,mt8186-gce", .data = (void *)&gce_plat_mt8186},
	{.compatible = "mediatek,mt8188-gce", .data = (void *)&gce_plat_mt8188},
	{.compatible = "mediatek,mt8192-gce", .data = (void *)&gce_plat_mt8192},
	{.compatible = "mediatek,mt8195-gce", .data = (void *)&gce_plat_mt8195},
	{.compatible = "mediatek,mt8196-gce", .data = (void *)&gce_plat_mt8196},
	{}
};
MODULE_DEVICE_TABLE(of, cmdq_of_ids);

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,
	}
};

static int __init cmdq_drv_init(void)
{
	return platform_driver_register(&cmdq_drv);
}

static void __exit cmdq_drv_exit(void)
{
	platform_driver_unregister(&cmdq_drv);
}

subsys_initcall(cmdq_drv_init);
module_exit(cmdq_drv_exit);

MODULE_DESCRIPTION("Mediatek Command Queue(CMDQ) Mailbox driver");
MODULE_LICENSE("GPL v2");