remoteproc: imx_dsp_rproc: Add remoteproc driver for DSP on i.MX

Provide a basic driver to control DSP processor found on NXP i.MX8QM,
i.MX8QXP, i.MX8MP and i.MX8ULP.

Currently it is able to resolve addresses between DSP and main CPU,
start and stop the processor, suspend and resume.

The communication between DSP and main CPU is based on mailbox, there
are three mailbox channels (tx, rx, rxdb).

This driver was tested on NXP i.MX8QM, i.MX8QXP, i.MX8MP and i.MX8ULP.

Signed-off-by: Shengjiu Wang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mathieu Poirier <[e-mail]>

drivers/remoteproc/Kconfig

···
 
 	  It's safe to say N here.
 
+config IMX_DSP_REMOTEPROC
+	tristate "i.MX DSP remoteproc support"
+	depends on ARCH_MXC
+	depends on HAVE_ARM_SMCCC
+	select MAILBOX
+	help
+	  Say y here to support iMX's DSP remote processors via the remote
+	  processor framework.
+
+	  It's safe to say N here.
+
 config INGENIC_VPU_RPROC
 	tristate "Ingenic JZ47xx VPU remoteproc support"
 	depends on MIPS || COMPILE_TEST

drivers/remoteproc/Makefile

···
 remoteproc-y				+= remoteproc_elf_loader.o
 obj-$(CONFIG_REMOTEPROC_CDEV)		+= remoteproc_cdev.o
 obj-$(CONFIG_IMX_REMOTEPROC)		+= imx_rproc.o
+obj-$(CONFIG_IMX_DSP_REMOTEPROC)	+= imx_dsp_rproc.o
 obj-$(CONFIG_INGENIC_VPU_RPROC)		+= ingenic_rproc.o
 obj-$(CONFIG_MTK_SCP)			+= mtk_scp.o mtk_scp_ipi.o
 obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o

drivers/remoteproc/imx_dsp_rproc.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright 2021 NXP
+
+#include <dt-bindings/firmware/imx/rsrc.h>
+#include <linux/arm-smccc.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/firmware/imx/sci.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/remoteproc.h>
+#include <linux/slab.h>
+
+#include "imx_rproc.h"
+#include "remoteproc_elf_helpers.h"
+#include "remoteproc_internal.h"
+
+#define DSP_RPROC_CLK_MAX			5
+
+#define REMOTE_IS_READY				BIT(0)
+#define REMOTE_READY_WAIT_MAX_RETRIES		500
+
+/* att flags */
+/* DSP own area */
+#define ATT_OWN					BIT(31)
+/* DSP instruction area */
+#define ATT_IRAM				BIT(30)
+
+/* Definitions for i.MX8MP */
+/* DAP registers */
+#define IMX8M_DAP_DEBUG				0x28800000
+#define IMX8M_DAP_DEBUG_SIZE			(64 * 1024)
+#define IMX8M_DAP_PWRCTL			(0x4000 + 0x3020)
+#define IMX8M_PWRCTL_CORERESET			BIT(16)
+
+/* DSP audio mix registers */
+#define IMX8M_AudioDSP_REG0			0x100
+#define IMX8M_AudioDSP_REG1			0x104
+#define IMX8M_AudioDSP_REG2			0x108
+#define IMX8M_AudioDSP_REG3			0x10c
+
+#define IMX8M_AudioDSP_REG2_RUNSTALL		BIT(5)
+#define IMX8M_AudioDSP_REG2_PWAITMODE		BIT(1)
+
+/* Definitions for i.MX8ULP */
+#define IMX8ULP_SIM_LPAV_REG_SYSCTRL0		0x8
+#define IMX8ULP_SYSCTRL0_DSP_DBG_RST		BIT(25)
+#define IMX8ULP_SYSCTRL0_DSP_PLAT_CLK_EN	BIT(19)
+#define IMX8ULP_SYSCTRL0_DSP_PBCLK_EN		BIT(18)
+#define IMX8ULP_SYSCTRL0_DSP_CLK_EN		BIT(17)
+#define IMX8ULP_SYSCTRL0_DSP_RST		BIT(16)
+#define IMX8ULP_SYSCTRL0_DSP_OCD_HALT		BIT(14)
+#define IMX8ULP_SYSCTRL0_DSP_STALL		BIT(13)
+
+#define IMX8ULP_SIP_HIFI_XRDC			0xc200000e
+
+/*
+ * enum - Predefined Mailbox Messages
+ *
+ * @RP_MBOX_SUSPEND_SYSTEM: system suspend request for the remote processor
+ *
+ * @RP_MBOX_SUSPEND_ACK: successful response from remote processor for a
+ * suspend request
+ *
+ * @RP_MBOX_RESUME_SYSTEM: system resume request for the remote processor
+ *
+ * @RP_MBOX_RESUME_ACK: successful response from remote processor for a
+ * resume request
+ */
+enum imx_dsp_rp_mbox_messages {
+	RP_MBOX_SUSPEND_SYSTEM			= 0xFF11,
+	RP_MBOX_SUSPEND_ACK			= 0xFF12,
+	RP_MBOX_RESUME_SYSTEM			= 0xFF13,
+	RP_MBOX_RESUME_ACK			= 0xFF14,
+};
+
+/**
+ * struct imx_dsp_rproc - DSP remote processor state
+ * @regmap: regmap handler
+ * @rproc: rproc handler
+ * @dsp_dcfg: device configuration pointer
+ * @clks: clocks needed by this device
+ * @cl: mailbox client to request the mailbox channel
+ * @cl_rxdb: mailbox client to request the mailbox channel for doorbell
+ * @tx_ch: mailbox tx channel handle
+ * @rx_ch: mailbox rx channel handle
+ * @rxdb_ch: mailbox rx doorbell channel handle
+ * @pd_dev: power domain device
+ * @pd_dev_link: power domain device link
+ * @ipc_handle: System Control Unit ipc handle
+ * @rproc_work: work for processing virtio interrupts
+ * @pm_comp: completion primitive to sync for suspend response
+ * @num_domains: power domain number
+ * @flags: control flags
+ */
+struct imx_dsp_rproc {
+	struct regmap				*regmap;
+	struct rproc				*rproc;
+	const struct imx_dsp_rproc_dcfg		*dsp_dcfg;
+	struct clk_bulk_data			clks[DSP_RPROC_CLK_MAX];
+	struct mbox_client			cl;
+	struct mbox_client			cl_rxdb;
+	struct mbox_chan			*tx_ch;
+	struct mbox_chan			*rx_ch;
+	struct mbox_chan			*rxdb_ch;
+	struct device				**pd_dev;
+	struct device_link			**pd_dev_link;
+	struct imx_sc_ipc			*ipc_handle;
+	struct work_struct			rproc_work;
+	struct completion			pm_comp;
+	int					num_domains;
+	u32					flags;
+};
+
+/**
+ * struct imx_dsp_rproc_dcfg - DSP remote processor configuration
+ * @dcfg: imx_rproc_dcfg handler
+ * @reset: reset callback function
+ */
+struct imx_dsp_rproc_dcfg {
+	const struct imx_rproc_dcfg		*dcfg;
+	int (*reset)(struct imx_dsp_rproc *priv);
+};
+
+static const struct imx_rproc_att imx_dsp_rproc_att_imx8qm[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	{ 0x596e8000, 0x556e8000, 0x00008000, ATT_OWN },
+	{ 0x596f0000, 0x556f0000, 0x00008000, ATT_OWN },
+	{ 0x596f8000, 0x556f8000, 0x00000800, ATT_OWN | ATT_IRAM},
+	{ 0x55700000, 0x55700000, 0x00070000, ATT_OWN },
+	/* DDR (Data) */
+	{ 0x80000000, 0x80000000, 0x60000000, 0},
+};
+
+static const struct imx_rproc_att imx_dsp_rproc_att_imx8qxp[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	{ 0x596e8000, 0x596e8000, 0x00008000, ATT_OWN },
+	{ 0x596f0000, 0x596f0000, 0x00008000, ATT_OWN },
+	{ 0x596f8000, 0x596f8000, 0x00000800, ATT_OWN | ATT_IRAM},
+	{ 0x59700000, 0x59700000, 0x00070000, ATT_OWN },
+	/* DDR (Data) */
+	{ 0x80000000, 0x80000000, 0x60000000, 0},
+};
+
+static const struct imx_rproc_att imx_dsp_rproc_att_imx8mp[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	{ 0x3b6e8000, 0x3b6e8000, 0x00008000, ATT_OWN },
+	{ 0x3b6f0000, 0x3b6f0000, 0x00008000, ATT_OWN },
+	{ 0x3b6f8000, 0x3b6f8000, 0x00000800, ATT_OWN | ATT_IRAM},
+	{ 0x3b700000, 0x3b700000, 0x00040000, ATT_OWN },
+	/* DDR (Data) */
+	{ 0x40000000, 0x40000000, 0x80000000, 0},
+};
+
+static const struct imx_rproc_att imx_dsp_rproc_att_imx8ulp[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	{ 0x21170000, 0x21170000, 0x00010000, ATT_OWN | ATT_IRAM},
+	{ 0x21180000, 0x21180000, 0x00010000, ATT_OWN },
+	/* DDR (Data) */
+	{ 0x0c000000, 0x80000000, 0x10000000, 0},
+	{ 0x30000000, 0x90000000, 0x10000000, 0},
+};
+
+/* Reset function for DSP on i.MX8MP */
+static int imx8mp_dsp_reset(struct imx_dsp_rproc *priv)
+{
+	void __iomem *dap = ioremap_wc(IMX8M_DAP_DEBUG, IMX8M_DAP_DEBUG_SIZE);
+	int pwrctl;
+
+	/* Put DSP into reset and stall */
+	pwrctl = readl(dap + IMX8M_DAP_PWRCTL);
+	pwrctl |= IMX8M_PWRCTL_CORERESET;
+	writel(pwrctl, dap + IMX8M_DAP_PWRCTL);
+
+	/* Keep reset asserted for 10 cycles */
+	usleep_range(1, 2);
+
+	regmap_update_bits(priv->regmap, IMX8M_AudioDSP_REG2,
+			   IMX8M_AudioDSP_REG2_RUNSTALL,
+			   IMX8M_AudioDSP_REG2_RUNSTALL);
+
+	/* Take the DSP out of reset and keep stalled for FW loading */
+	pwrctl = readl(dap + IMX8M_DAP_PWRCTL);
+	pwrctl &= ~IMX8M_PWRCTL_CORERESET;
+	writel(pwrctl, dap + IMX8M_DAP_PWRCTL);
+
+	iounmap(dap);
+	return 0;
+}
+
+/* Reset function for DSP on i.MX8ULP */
+static int imx8ulp_dsp_reset(struct imx_dsp_rproc *priv)
+{
+	struct arm_smccc_res res;
+
+	/* Put DSP into reset and stall */
+	regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
+			   IMX8ULP_SYSCTRL0_DSP_RST, IMX8ULP_SYSCTRL0_DSP_RST);
+	regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
+			   IMX8ULP_SYSCTRL0_DSP_STALL,
+			   IMX8ULP_SYSCTRL0_DSP_STALL);
+
+	/* Configure resources of DSP through TFA */
+	arm_smccc_smc(IMX8ULP_SIP_HIFI_XRDC, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	/* Take the DSP out of reset and keep stalled for FW loading */
+	regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
+			   IMX8ULP_SYSCTRL0_DSP_RST, 0);
+	regmap_update_bits(priv->regmap, IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
+			   IMX8ULP_SYSCTRL0_DSP_DBG_RST, 0);
+
+	return 0;
+}
+
+/* Specific configuration for i.MX8MP */
+static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8mp = {
+	.src_reg	= IMX8M_AudioDSP_REG2,
+	.src_mask	= IMX8M_AudioDSP_REG2_RUNSTALL,
+	.src_start	= 0,
+	.src_stop	= IMX8M_AudioDSP_REG2_RUNSTALL,
+	.att		= imx_dsp_rproc_att_imx8mp,
+	.att_size	= ARRAY_SIZE(imx_dsp_rproc_att_imx8mp),
+	.method		= IMX_RPROC_MMIO,
+};
+
+static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8mp = {
+	.dcfg		= &dsp_rproc_cfg_imx8mp,
+	.reset          = imx8mp_dsp_reset,
+};
+
+/* Specific configuration for i.MX8ULP */
+static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8ulp = {
+	.src_reg	= IMX8ULP_SIM_LPAV_REG_SYSCTRL0,
+	.src_mask	= IMX8ULP_SYSCTRL0_DSP_STALL,
+	.src_start	= 0,
+	.src_stop	= IMX8ULP_SYSCTRL0_DSP_STALL,
+	.att		= imx_dsp_rproc_att_imx8ulp,
+	.att_size	= ARRAY_SIZE(imx_dsp_rproc_att_imx8ulp),
+	.method		= IMX_RPROC_MMIO,
+};
+
+static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8ulp = {
+	.dcfg		= &dsp_rproc_cfg_imx8ulp,
+	.reset          = imx8ulp_dsp_reset,
+};
+
+/* Specific configuration for i.MX8QXP */
+static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8qxp = {
+	.att		= imx_dsp_rproc_att_imx8qxp,
+	.att_size	= ARRAY_SIZE(imx_dsp_rproc_att_imx8qxp),
+	.method		= IMX_RPROC_SCU_API,
+};
+
+static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8qxp = {
+	.dcfg		= &dsp_rproc_cfg_imx8qxp,
+};
+
+/* Specific configuration for i.MX8QM */
+static const struct imx_rproc_dcfg dsp_rproc_cfg_imx8qm = {
+	.att		= imx_dsp_rproc_att_imx8qm,
+	.att_size	= ARRAY_SIZE(imx_dsp_rproc_att_imx8qm),
+	.method		= IMX_RPROC_SCU_API,
+};
+
+static const struct imx_dsp_rproc_dcfg imx_dsp_rproc_cfg_imx8qm = {
+	.dcfg		= &dsp_rproc_cfg_imx8qm,
+};
+
+static int imx_dsp_rproc_ready(struct rproc *rproc)
+{
+	struct imx_dsp_rproc *priv = rproc->priv;
+	int i;
+
+	if (!priv->rxdb_ch)
+		return 0;
+
+	for (i = 0; i < REMOTE_READY_WAIT_MAX_RETRIES; i++) {
+		if (priv->flags & REMOTE_IS_READY)
+			return 0;
+		usleep_range(100, 200);
+	}
+
+	return -ETIMEDOUT;
+}
+
+/*
+ * Start function for rproc_ops
+ *
+ * There is a handshake for start procedure: when DSP starts, it
+ * will send a doorbell message to this driver, then the
+ * REMOTE_IS_READY flags is set, then driver will kick
+ * a message to DSP.
+ */
+static int imx_dsp_rproc_start(struct rproc *rproc)
+{
+	struct imx_dsp_rproc *priv = rproc->priv;
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
+	struct device *dev = rproc->dev.parent;
+	int ret;
+
+	switch (dcfg->method) {
+	case IMX_RPROC_MMIO:
+		ret = regmap_update_bits(priv->regmap,
+					 dcfg->src_reg,
+					 dcfg->src_mask,
+					 dcfg->src_start);
+		break;
+	case IMX_RPROC_SCU_API:
+		ret = imx_sc_pm_cpu_start(priv->ipc_handle,
+					  IMX_SC_R_DSP,
+					  true,
+					  rproc->bootaddr);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (ret)
+		dev_err(dev, "Failed to enable remote core!\n");
+	else
+		ret = imx_dsp_rproc_ready(rproc);
+
+	return ret;
+}
+
+/*
+ * Stop function for rproc_ops
+ * It clears the REMOTE_IS_READY flags
+ */
+static int imx_dsp_rproc_stop(struct rproc *rproc)
+{
+	struct imx_dsp_rproc *priv = rproc->priv;
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
+	struct device *dev = rproc->dev.parent;
+	int ret = 0;
+
+	/* Make sure work is finished */
+	flush_work(&priv->rproc_work);
+
+	if (rproc->state == RPROC_CRASHED) {
+		priv->flags &= ~REMOTE_IS_READY;
+		return 0;
+	}
+
+	switch (dcfg->method) {
+	case IMX_RPROC_MMIO:
+		ret = regmap_update_bits(priv->regmap, dcfg->src_reg, dcfg->src_mask,
+					 dcfg->src_stop);
+		break;
+	case IMX_RPROC_SCU_API:
+		ret = imx_sc_pm_cpu_start(priv->ipc_handle,
+					  IMX_SC_R_DSP,
+					  false,
+					  rproc->bootaddr);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	if (ret)
+		dev_err(dev, "Failed to stop remote core\n");
+	else
+		priv->flags &= ~REMOTE_IS_READY;
+
+	return ret;
+}
+
+/**
+ * imx_dsp_rproc_sys_to_da() - internal memory translation helper
+ * @priv: private data pointer
+ * @sys: system address (DDR address)
+ * @len: length of the memory buffer
+ * @da: device address to translate
+ *
+ * Convert system address (DDR address) to device address (DSP)
+ * for there may be memory remap for device.
+ */
+static int imx_dsp_rproc_sys_to_da(struct imx_dsp_rproc *priv, u64 sys,
+				   size_t len, u64 *da)
+{
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
+	int i;
+
+	/* Parse address translation table */
+	for (i = 0; i < dcfg->att_size; i++) {
+		const struct imx_rproc_att *att = &dcfg->att[i];
+
+		if (sys >= att->sa && sys + len <= att->sa + att->size) {
+			unsigned int offset = sys - att->sa;
+
+			*da = att->da + offset;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/* Main virtqueue message work function
+ *
+ * This function is executed upon scheduling of the i.MX DSP remoteproc
+ * driver's workqueue. The workqueue is scheduled by the mailbox rx
+ * handler.
+ *
+ * This work function processes both the Tx and Rx virtqueue indices on
+ * every invocation. The rproc_vq_interrupt function can detect if there
+ * are new unprocessed messages or not (returns IRQ_NONE vs IRQ_HANDLED),
+ * but there is no need to check for these return values. The index 0
+ * triggering will process all pending Rx buffers, and the index 1 triggering
+ * will process all newly available Tx buffers and will wakeup any potentially
+ * blocked senders.
+ *
+ * NOTE:
+ *    The current logic is based on an inherent design assumption of supporting
+ *    only 2 vrings, but this can be changed if needed.
+ */
+static void imx_dsp_rproc_vq_work(struct work_struct *work)
+{
+	struct imx_dsp_rproc *priv = container_of(work, struct imx_dsp_rproc,
+						  rproc_work);
+
+	rproc_vq_interrupt(priv->rproc, 0);
+	rproc_vq_interrupt(priv->rproc, 1);
+}
+
+/**
+ * imx_dsp_rproc_rx_tx_callback() - inbound mailbox message handler
+ * @cl: mailbox client pointer used for requesting the mailbox channel
+ * @data: mailbox payload
+ *
+ * This handler is invoked by mailbox driver whenever a mailbox
+ * message is received. Usually, the SUSPEND and RESUME related messages
+ * are handled in this function, other messages are handled by remoteproc core
+ */
+static void imx_dsp_rproc_rx_tx_callback(struct mbox_client *cl, void *data)
+{
+	struct rproc *rproc = dev_get_drvdata(cl->dev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+	struct device *dev = rproc->dev.parent;
+	u32 message = (u32)(*(u32 *)data);
+
+	dev_dbg(dev, "mbox msg: 0x%x\n", message);
+
+	switch (message) {
+	case RP_MBOX_SUSPEND_ACK:
+		complete(&priv->pm_comp);
+		break;
+	case RP_MBOX_RESUME_ACK:
+		complete(&priv->pm_comp);
+		break;
+	default:
+		schedule_work(&priv->rproc_work);
+		break;
+	}
+}
+
+/**
+ * imx_dsp_rproc_rxdb_callback() - inbound mailbox message handler
+ * @cl: mailbox client pointer used for requesting the mailbox channel
+ * @data: mailbox payload
+ *
+ * For doorbell, there is no message specified, just set REMOTE_IS_READY
+ * flag.
+ */
+static void imx_dsp_rproc_rxdb_callback(struct mbox_client *cl, void *data)
+{
+	struct rproc *rproc = dev_get_drvdata(cl->dev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+
+	/* Remote is ready after firmware is loaded and running */
+	priv->flags |= REMOTE_IS_READY;
+}
+
+/**
+ * imx_dsp_rproc_mbox_init() - request mailbox channels
+ * @priv: private data pointer
+ *
+ * Request three mailbox channels (tx, rx, rxdb).
+ */
+static int imx_dsp_rproc_mbox_init(struct imx_dsp_rproc *priv)
+{
+	struct device *dev = priv->rproc->dev.parent;
+	struct mbox_client *cl;
+	int ret;
+
+	if (!of_get_property(dev->of_node, "mbox-names", NULL))
+		return 0;
+
+	cl = &priv->cl;
+	cl->dev = dev;
+	cl->tx_block = true;
+	cl->tx_tout = 100;
+	cl->knows_txdone = false;
+	cl->rx_callback = imx_dsp_rproc_rx_tx_callback;
+
+	/* Channel for sending message */
+	priv->tx_ch = mbox_request_channel_byname(cl, "tx");
+	if (IS_ERR(priv->tx_ch)) {
+		ret = PTR_ERR(priv->tx_ch);
+		dev_dbg(cl->dev, "failed to request tx mailbox channel: %d\n",
+			ret);
+		goto err_out;
+	}
+
+	/* Channel for receiving message */
+	priv->rx_ch = mbox_request_channel_byname(cl, "rx");
+	if (IS_ERR(priv->rx_ch)) {
+		ret = PTR_ERR(priv->rx_ch);
+		dev_dbg(cl->dev, "failed to request rx mailbox channel: %d\n",
+			ret);
+		goto err_out;
+	}
+
+	cl = &priv->cl_rxdb;
+	cl->dev = dev;
+	cl->rx_callback = imx_dsp_rproc_rxdb_callback;
+
+	/*
+	 * RX door bell is used to receive the ready signal from remote
+	 * after firmware loaded.
+	 */
+	priv->rxdb_ch = mbox_request_channel_byname(cl, "rxdb");
+	if (IS_ERR(priv->rxdb_ch)) {
+		ret = PTR_ERR(priv->rxdb_ch);
+		dev_dbg(cl->dev, "failed to request mbox chan rxdb, ret %d\n",
+			ret);
+		goto err_out;
+	}
+
+	return 0;
+
+err_out:
+	if (!IS_ERR(priv->tx_ch))
+		mbox_free_channel(priv->tx_ch);
+	if (!IS_ERR(priv->rx_ch))
+		mbox_free_channel(priv->rx_ch);
+	if (!IS_ERR(priv->rxdb_ch))
+		mbox_free_channel(priv->rxdb_ch);
+
+	return ret;
+}
+
+static void imx_dsp_rproc_free_mbox(struct imx_dsp_rproc *priv)
+{
+	mbox_free_channel(priv->tx_ch);
+	mbox_free_channel(priv->rx_ch);
+	mbox_free_channel(priv->rxdb_ch);
+}
+
+/**
+ * imx_dsp_rproc_add_carveout() - request mailbox channels
+ * @priv: private data pointer
+ *
+ * This function registers specified memory entry in @rproc carveouts list
+ * The carveouts can help to mapping the memory address for DSP.
+ */
+static int imx_dsp_rproc_add_carveout(struct imx_dsp_rproc *priv)
+{
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	const struct imx_rproc_dcfg *dcfg = dsp_dcfg->dcfg;
+	struct rproc *rproc = priv->rproc;
+	struct device *dev = rproc->dev.parent;
+	struct device_node *np = dev->of_node;
+	struct of_phandle_iterator it;
+	struct rproc_mem_entry *mem;
+	struct reserved_mem *rmem;
+	void __iomem *cpu_addr;
+	int a;
+	u64 da;
+
+	/* Remap required addresses */
+	for (a = 0; a < dcfg->att_size; a++) {
+		const struct imx_rproc_att *att = &dcfg->att[a];
+
+		if (!(att->flags & ATT_OWN))
+			continue;
+
+		if (imx_dsp_rproc_sys_to_da(priv, att->sa, att->size, &da))
+			return -EINVAL;
+
+		cpu_addr = devm_ioremap_wc(dev, att->sa, att->size);
+		if (!cpu_addr) {
+			dev_err(dev, "failed to map memory %p\n", &att->sa);
+			return -ENOMEM;
+		}
+
+		/* Register memory region */
+		mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)att->sa,
+					   att->size, da, NULL, NULL, "dsp_mem");
+
+		if (mem)
+			rproc_coredump_add_segment(rproc, da, att->size);
+		else
+			return -ENOMEM;
+
+		rproc_add_carveout(rproc, mem);
+	}
+
+	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
+	while (of_phandle_iterator_next(&it) == 0) {
+		/*
+		 * Ignore the first memory region which will be used vdev buffer.
+		 * No need to do extra handlings, rproc_add_virtio_dev will handle it.
+		 */
+		if (!strcmp(it.node->name, "vdev0buffer"))
+			continue;
+
+		rmem = of_reserved_mem_lookup(it.node);
+		if (!rmem) {
+			dev_err(dev, "unable to acquire memory-region\n");
+			return -EINVAL;
+		}
+
+		if (imx_dsp_rproc_sys_to_da(priv, rmem->base, rmem->size, &da))
+			return -EINVAL;
+
+		cpu_addr = devm_ioremap_wc(dev, rmem->base, rmem->size);
+		if (!cpu_addr) {
+			dev_err(dev, "failed to map memory %p\n", &rmem->base);
+			return -ENOMEM;
+		}
+
+		/* Register memory region */
+		mem = rproc_mem_entry_init(dev, cpu_addr, (dma_addr_t)rmem->base,
+					   rmem->size, da, NULL, NULL, it.node->name);
+
+		if (mem)
+			rproc_coredump_add_segment(rproc, da, rmem->size);
+		else
+			return -ENOMEM;
+
+		rproc_add_carveout(rproc, mem);
+	}
+
+	return 0;
+}
+
+/**
+ * imx_dsp_rproc_elf_load_segments() - load firmware segments to memory
+ * @rproc: remote processor which will be booted using these fw segments
+ * @fw: the ELF firmware image
+ *
+ * This function specially checks if memsz is zero or not, otherwise it
+ * is mostly same as rproc_elf_load_segments().
+ */
+static int imx_dsp_rproc_elf_load_segments(struct rproc *rproc,
+					   const struct firmware *fw)
+{
+	struct device *dev = &rproc->dev;
+	u8 class = fw_elf_get_class(fw);
+	u32 elf_phdr_get_size = elf_size_of_phdr(class);
+	const u8 *elf_data = fw->data;
+	const void *ehdr, *phdr;
+	int i, ret = 0;
+	u16 phnum;
+
+	ehdr = elf_data;
+	phnum = elf_hdr_get_e_phnum(class, ehdr);
+	phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
+
+	/* go through the available ELF segments */
+	for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
+		u64 da = elf_phdr_get_p_paddr(class, phdr);
+		u64 memsz = elf_phdr_get_p_memsz(class, phdr);
+		u64 filesz = elf_phdr_get_p_filesz(class, phdr);
+		u64 offset = elf_phdr_get_p_offset(class, phdr);
+		u32 type = elf_phdr_get_p_type(class, phdr);
+		void *ptr;
+
+		/*
+		 *  There is a case that with PT_LOAD type, the
+		 *  filesz = memsz = 0. If memsz = 0, rproc_da_to_va
+		 *  should return NULL ptr, then error is returned.
+		 *  So this case should be skipped from the loop.
+		 *  Add !memsz checking here.
+		 */
+		if (type != PT_LOAD || !memsz)
+			continue;
+
+		dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx filesz 0x%llx\n",
+			type, da, memsz, filesz);
+
+		if (filesz > memsz) {
+			dev_err(dev, "bad phdr filesz 0x%llx memsz 0x%llx\n",
+				filesz, memsz);
+			ret = -EINVAL;
+			break;
+		}
+
+		if (offset + filesz > fw->size) {
+			dev_err(dev, "truncated fw: need 0x%llx avail 0x%zx\n",
+				offset + filesz, fw->size);
+			ret = -EINVAL;
+			break;
+		}
+
+		if (!rproc_u64_fit_in_size_t(memsz)) {
+			dev_err(dev, "size (%llx) does not fit in size_t type\n",
+				memsz);
+			ret = -EOVERFLOW;
+			break;
+		}
+
+		/* grab the kernel address for this device address */
+		ptr = rproc_da_to_va(rproc, da, memsz, NULL);
+		if (!ptr) {
+			dev_err(dev, "bad phdr da 0x%llx mem 0x%llx\n", da,
+				memsz);
+			ret = -EINVAL;
+			break;
+		}
+
+		/* put the segment where the remote processor expects it */
+		if (filesz)
+			memcpy(ptr, elf_data + offset, filesz);
+
+		/*
+		 * Zero out remaining memory for this segment.
+		 *
+		 * This isn't strictly required since dma_alloc_coherent already
+		 * did this for us. albeit harmless, we may consider removing
+		 * this.
+		 */
+		if (memsz > filesz)
+			memset(ptr + filesz, 0, memsz - filesz);
+	}
+
+	return ret;
+}
+
+/* Prepare function for rproc_ops */
+static int imx_dsp_rproc_prepare(struct rproc *rproc)
+{
+	struct imx_dsp_rproc *priv = rproc->priv;
+	struct device *dev = rproc->dev.parent;
+	struct rproc_mem_entry *carveout;
+	int ret;
+
+	ret = imx_dsp_rproc_add_carveout(priv);
+	if (ret) {
+		dev_err(dev, "failed on imx_dsp_rproc_add_carveout\n");
+		return ret;
+	}
+
+	pm_runtime_get_sync(dev);
+
+	/*
+	 * Clear buffers after pm rumtime for internal ocram is not
+	 * accessible if power and clock are not enabled.
+	 */
+	list_for_each_entry(carveout, &rproc->carveouts, node) {
+		if (carveout->va)
+			memset(carveout->va, 0, carveout->len);
+	}
+
+	return  0;
+}
+
+/* Unprepare function for rproc_ops */
+static int imx_dsp_rproc_unprepare(struct rproc *rproc)
+{
+	pm_runtime_put_sync(rproc->dev.parent);
+
+	return  0;
+}
+
+/* Kick function for rproc_ops */
+static void imx_dsp_rproc_kick(struct rproc *rproc, int vqid)
+{
+	struct imx_dsp_rproc *priv = rproc->priv;
+	struct device *dev = rproc->dev.parent;
+	int err;
+	__u32 mmsg;
+
+	if (!priv->tx_ch) {
+		dev_err(dev, "No initialized mbox tx channel\n");
+		return;
+	}
+
+	/*
+	 * Send the index of the triggered virtqueue as the mu payload.
+	 * Let remote processor know which virtqueue is used.
+	 */
+	mmsg = vqid;
+
+	err = mbox_send_message(priv->tx_ch, (void *)&mmsg);
+	if (err < 0)
+		dev_err(dev, "%s: failed (%d, err:%d)\n", __func__, vqid, err);
+}
+
+static const struct rproc_ops imx_dsp_rproc_ops = {
+	.prepare	= imx_dsp_rproc_prepare,
+	.unprepare	= imx_dsp_rproc_unprepare,
+	.start		= imx_dsp_rproc_start,
+	.stop		= imx_dsp_rproc_stop,
+	.kick		= imx_dsp_rproc_kick,
+	.load		= imx_dsp_rproc_elf_load_segments,
+	.parse_fw	= rproc_elf_load_rsc_table,
+	.sanity_check	= rproc_elf_sanity_check,
+	.get_boot_addr	= rproc_elf_get_boot_addr,
+};
+
+/**
+ * imx_dsp_attach_pm_domains() - attach the power domains
+ * @priv: private data pointer
+ *
+ * On i.MX8QM and i.MX8QXP there is multiple power domains
+ * required, so need to link them.
+ */
+static int imx_dsp_attach_pm_domains(struct imx_dsp_rproc *priv)
+{
+	struct device *dev = priv->rproc->dev.parent;
+	int ret, i;
+
+	priv->num_domains = of_count_phandle_with_args(dev->of_node,
+						       "power-domains",
+						       "#power-domain-cells");
+
+	/* If only one domain, then no need to link the device */
+	if (priv->num_domains <= 1)
+		return 0;
+
+	priv->pd_dev = devm_kmalloc_array(dev, priv->num_domains,
+					  sizeof(*priv->pd_dev),
+					  GFP_KERNEL);
+	if (!priv->pd_dev)
+		return -ENOMEM;
+
+	priv->pd_dev_link = devm_kmalloc_array(dev, priv->num_domains,
+					       sizeof(*priv->pd_dev_link),
+					       GFP_KERNEL);
+	if (!priv->pd_dev_link)
+		return -ENOMEM;
+
+	for (i = 0; i < priv->num_domains; i++) {
+		priv->pd_dev[i] = dev_pm_domain_attach_by_id(dev, i);
+		if (IS_ERR(priv->pd_dev[i])) {
+			ret = PTR_ERR(priv->pd_dev[i]);
+			goto detach_pm;
+		}
+
+		/*
+		 * device_link_add will check priv->pd_dev[i], if it is
+		 * NULL, then will break.
+		 */
+		priv->pd_dev_link[i] = device_link_add(dev,
+						       priv->pd_dev[i],
+						       DL_FLAG_STATELESS |
+						       DL_FLAG_PM_RUNTIME);
+		if (!priv->pd_dev_link[i]) {
+			dev_pm_domain_detach(priv->pd_dev[i], false);
+			ret = -EINVAL;
+			goto detach_pm;
+		}
+	}
+
+	return 0;
+
+detach_pm:
+	while (--i >= 0) {
+		device_link_del(priv->pd_dev_link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+
+	return ret;
+}
+
+static int imx_dsp_detach_pm_domains(struct imx_dsp_rproc *priv)
+{
+	int i;
+
+	if (priv->num_domains <= 1)
+		return 0;
+
+	for (i = 0; i < priv->num_domains; i++) {
+		device_link_del(priv->pd_dev_link[i]);
+		dev_pm_domain_detach(priv->pd_dev[i], false);
+	}
+
+	return 0;
+}
+
+/**
+ * imx_dsp_rproc_detect_mode() - detect DSP control mode
+ * @priv: private data pointer
+ *
+ * Different platform has different control method for DSP, which depends
+ * on how the DSP is integrated in platform.
+ *
+ * For i.MX8QXP and i.MX8QM, DSP should be started and stopped by System
+ * Control Unit.
+ * For i.MX8MP and i.MX8ULP, DSP should be started and stopped by system
+ * integration module.
+ */
+static int imx_dsp_rproc_detect_mode(struct imx_dsp_rproc *priv)
+{
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	struct device *dev = priv->rproc->dev.parent;
+	struct regmap *regmap;
+	int ret = 0;
+
+	switch (dsp_dcfg->dcfg->method) {
+	case IMX_RPROC_SCU_API:
+		ret = imx_scu_get_handle(&priv->ipc_handle);
+		if (ret)
+			return ret;
+		break;
+	case IMX_RPROC_MMIO:
+		regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "fsl,dsp-ctrl");
+		if (IS_ERR(regmap)) {
+			dev_err(dev, "failed to find syscon\n");
+			return PTR_ERR(regmap);
+		}
+
+		priv->regmap = regmap;
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
+static const char *imx_dsp_clks_names[DSP_RPROC_CLK_MAX] = {
+	/* DSP clocks */
+	"core", "ocram", "debug", "ipg", "mu",
+};
+
+static int imx_dsp_rproc_clk_get(struct imx_dsp_rproc *priv)
+{
+	struct device *dev = priv->rproc->dev.parent;
+	struct clk_bulk_data *clks = priv->clks;
+	int i;
+
+	for (i = 0; i < DSP_RPROC_CLK_MAX; i++)
+		clks[i].id = imx_dsp_clks_names[i];
+
+	return devm_clk_bulk_get_optional(dev, DSP_RPROC_CLK_MAX, clks);
+}
+
+static int imx_dsp_rproc_probe(struct platform_device *pdev)
+{
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg;
+	struct device *dev = &pdev->dev;
+	struct imx_dsp_rproc *priv;
+	struct rproc *rproc;
+	const char *fw_name;
+	int ret;
+
+	dsp_dcfg = of_device_get_match_data(dev);
+	if (!dsp_dcfg)
+		return -ENODEV;
+
+	ret = rproc_of_parse_firmware(dev, 0, &fw_name);
+	if (ret) {
+		dev_err(dev, "failed to parse firmware-name property, ret = %d\n",
+			ret);
+		return ret;
+	}
+
+	rproc = rproc_alloc(dev, "imx-dsp-rproc", &imx_dsp_rproc_ops, fw_name,
+			    sizeof(*priv));
+	if (!rproc)
+		return -ENOMEM;
+
+	priv = rproc->priv;
+	priv->rproc = rproc;
+	priv->dsp_dcfg = dsp_dcfg;
+
+	dev_set_drvdata(dev, rproc);
+
+	INIT_WORK(&priv->rproc_work, imx_dsp_rproc_vq_work);
+
+	ret = imx_dsp_rproc_detect_mode(priv);
+	if (ret) {
+		dev_err(dev, "failed on imx_dsp_rproc_detect_mode\n");
+		goto err_put_rproc;
+	}
+
+	/* There are multiple power domains required by DSP on some platform */
+	ret = imx_dsp_attach_pm_domains(priv);
+	if (ret) {
+		dev_err(dev, "failed on imx_dsp_attach_pm_domains\n");
+		goto err_put_rproc;
+	}
+	/* Get clocks */
+	ret = imx_dsp_rproc_clk_get(priv);
+	if (ret) {
+		dev_err(dev, "failed on imx_dsp_rproc_clk_get\n");
+		goto err_detach_domains;
+	}
+
+	init_completion(&priv->pm_comp);
+	rproc->auto_boot = false;
+	ret = rproc_add(rproc);
+	if (ret) {
+		dev_err(dev, "rproc_add failed\n");
+		goto err_detach_domains;
+	}
+
+	pm_runtime_enable(dev);
+
+	return 0;
+
+err_detach_domains:
+	imx_dsp_detach_pm_domains(priv);
+err_put_rproc:
+	rproc_free(rproc);
+
+	return ret;
+}
+
+static int imx_dsp_rproc_remove(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+
+	pm_runtime_disable(&pdev->dev);
+	rproc_del(rproc);
+	imx_dsp_detach_pm_domains(priv);
+	rproc_free(rproc);
+
+	return 0;
+}
+
+/* pm runtime functions */
+static int imx_dsp_runtime_resume(struct device *dev)
+{
+	struct rproc *rproc = dev_get_drvdata(dev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+	const struct imx_dsp_rproc_dcfg *dsp_dcfg = priv->dsp_dcfg;
+	int ret;
+
+	/*
+	 * There is power domain attached with mailbox, if setup mailbox
+	 * in probe(), then the power of mailbox is always enabled,
+	 * the power can't be saved.
+	 * So move setup of mailbox to runtime resume.
+	 */
+	ret = imx_dsp_rproc_mbox_init(priv);
+	if (ret) {
+		dev_err(dev, "failed on imx_dsp_rproc_mbox_init\n");
+		return ret;
+	}
+
+	ret = clk_bulk_prepare_enable(DSP_RPROC_CLK_MAX, priv->clks);
+	if (ret) {
+		dev_err(dev, "failed on clk_bulk_prepare_enable\n");
+		return ret;
+	}
+
+	/* Reset DSP if needed */
+	if (dsp_dcfg->reset)
+		dsp_dcfg->reset(priv);
+
+	return 0;
+}
+
+static int imx_dsp_runtime_suspend(struct device *dev)
+{
+	struct rproc *rproc = dev_get_drvdata(dev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+
+	clk_bulk_disable_unprepare(DSP_RPROC_CLK_MAX, priv->clks);
+
+	imx_dsp_rproc_free_mbox(priv);
+
+	return 0;
+}
+
+static void imx_dsp_load_firmware(const struct firmware *fw, void *context)
+{
+	struct rproc *rproc = context;
+	int ret;
+
+	/*
+	 * Same flow as start procedure.
+	 * Load the ELF segments to memory firstly.
+	 */
+	ret = rproc_load_segments(rproc, fw);
+	if (ret)
+		goto out;
+
+	/* Start the remote processor */
+	ret = rproc->ops->start(rproc);
+	if (ret)
+		goto out;
+
+	rproc->ops->kick(rproc, 0);
+
+out:
+	release_firmware(fw);
+}
+
+static int imx_dsp_suspend(struct device *dev)
+{
+	struct rproc *rproc = dev_get_drvdata(dev);
+	struct imx_dsp_rproc *priv = rproc->priv;
+	__u32 mmsg = RP_MBOX_SUSPEND_SYSTEM;
+	int ret;
+
+	if (rproc->state != RPROC_RUNNING)
+		goto out;
+
+	reinit_completion(&priv->pm_comp);
+
+	/* Tell DSP that suspend is happening */
+	ret = mbox_send_message(priv->tx_ch, (void *)&mmsg);
+	if (ret < 0) {
+		dev_err(dev, "PM mbox_send_message failed: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * DSP need to save the context at suspend.
+	 * Here waiting the response for DSP, then power can be disabled.
+	 */
+	if (!wait_for_completion_timeout(&priv->pm_comp, msecs_to_jiffies(100)))
+		return -EBUSY;
+
+out:
+	/*
+	 * The power of DSP is disabled in suspend, so force pm runtime
+	 * to be suspend, then we can reenable the power and clocks at
+	 * resume stage.
+	 */
+	return pm_runtime_force_suspend(dev);
+}
+
+static int imx_dsp_resume(struct device *dev)
+{
+	struct rproc *rproc = dev_get_drvdata(dev);
+	int ret = 0;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret)
+		return ret;
+
+	if (rproc->state != RPROC_RUNNING)
+		return 0;
+
+	/*
+	 * The power of DSP is disabled at suspend, the memory of dsp
+	 * is reset, the image segments are lost. So need to reload
+	 * firmware and restart the DSP if it is in running state.
+	 */
+	ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT,
+				      rproc->firmware, dev, GFP_KERNEL,
+				      rproc, imx_dsp_load_firmware);
+	if (ret < 0) {
+		dev_err(dev, "load firmware failed: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	pm_runtime_force_suspend(dev);
+
+	return ret;
+}
+
+static const struct dev_pm_ops imx_dsp_rproc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(imx_dsp_suspend, imx_dsp_resume)
+	SET_RUNTIME_PM_OPS(imx_dsp_runtime_suspend,
+			   imx_dsp_runtime_resume, NULL)
+};
+
+static const struct of_device_id imx_dsp_rproc_of_match[] = {
+	{ .compatible = "fsl,imx8qxp-hifi4", .data = &imx_dsp_rproc_cfg_imx8qxp },
+	{ .compatible = "fsl,imx8qm-hifi4",  .data = &imx_dsp_rproc_cfg_imx8qm },
+	{ .compatible = "fsl,imx8mp-hifi4",  .data = &imx_dsp_rproc_cfg_imx8mp },
+	{ .compatible = "fsl,imx8ulp-hifi4", .data = &imx_dsp_rproc_cfg_imx8ulp },
+	{},
+};
+MODULE_DEVICE_TABLE(of, imx_dsp_rproc_of_match);
+
+static struct platform_driver imx_dsp_rproc_driver = {
+	.probe = imx_dsp_rproc_probe,
+	.remove = imx_dsp_rproc_remove,
+	.driver = {
+		.name = "imx-dsp-rproc",
+		.of_match_table = imx_dsp_rproc_of_match,
+		.pm = &imx_dsp_rproc_pm_ops,
+	},
+};
+module_platform_driver(imx_dsp_rproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("i.MX HiFi Core Remote Processor Control Driver");
+MODULE_AUTHOR("Shengjiu Wang <[e-mail]>");