Subject: [PATCH v4 06/11] remoteproc: wkup_m3: Add wkup_m3 remote proc driver

From: [email-masked] (Santosh Shilimkar)
Date: Mon, 14 Jul 2014 10:54:48 -0400

On Thursday 10 July 2014 10:55 PM, Dave Gerlach wrote:
> Add a remoteproc driver to load the firmware for and boot the wkup_m3
> present on am33xx. The wkup_m3 is an integrated Cortex M3 that allows
> the SoC to enter the lowest possible power state by taking control from
> the MPU after it has gone into its own low power state and shutting off
> any additional peripherals.
> 
> Communication between the MPU and CM3 is handled by several IPC
> registers in the control module and a mailbox. An API is exposed for
> programming the aforementioned IPC registers and notifying the wkup_m3
> of pending data using the mailbox. The wkup_m3 has the ability to
> trigger an interrupt back to the MPU to allow for bidirectional
> communication through these registers.
> 
> Two callbacks are provided. rproc_ready allows code to hook into the
> driver to see when firmware has been loaded and execute other code and
> txev_handler allows external code to run when the wkup_m3 triggers an
> interrupt back to the m3.
> 
> The driver expects a resource table to be present in the wkup_m3 to
> define the required memory resources needed by wkup_m3, at least the
> data memory so that the firmware can be copied for the proper place for
> execution.
> 
> Signed-off-by: Dave Gerlach <[email-masked]>
> CC: Ohad Ben-Cohen <[email-masked]>
> ---
>  drivers/remoteproc/Kconfig         |  15 ++
>  drivers/remoteproc/Makefile        |   1 +
>  drivers/remoteproc/wkup_m3_rproc.c | 512 +++++++++++++++++++++++++++++++++++++
>  include/linux/wkup_m3.h            |  71 +++++
>  4 files changed, 599 insertions(+)
>  create mode 100644 drivers/remoteproc/wkup_m3_rproc.c
>  create mode 100644 include/linux/wkup_m3.h
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index 5e343ba..4b00c21 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -41,6 +41,21 @@ config STE_MODEM_RPROC
>  	  This can be either built-in or a loadable module.
>  	  If unsure say N.
>  
> +config WKUP_M3_RPROC
> +	bool "AM33xx wkup-m3 remoteproc support"
> +        depends on SOC_AM33XX
> +        select REMOTEPROC
> +	select MAILBOX
> +	select OMAP2PLUS_MBOX
Please fix the indentation.

> +	default n
Default is always 'n' so drop above.
> +	help
> +	  Say y here to support AM33xx wkup-m3.
> +
> +	  Required for Suspend-to-ram and CPUIdle on AM33xx. Allows for
> +	  loading of firmware and communication with CM3 PM coproccesor
> +	  that is present on AM33xx family of SoCs
> +	  If unsure say N.
> +
>  config DA8XX_REMOTEPROC
>  	tristate "DA8xx/OMAP-L13x remoteproc support"
>  	depends on ARCH_DAVINCI_DA8XX
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index ac2ff75..81b04d1 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -9,4 +9,5 @@ remoteproc-y				+= remoteproc_virtio.o
>  remoteproc-y				+= remoteproc_elf_loader.o
>  obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
>  obj-$(CONFIG_STE_MODEM_RPROC)	 	+= ste_modem_rproc.o
> +obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
>  obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
> diff --git a/drivers/remoteproc/wkup_m3_rproc.c b/drivers/remoteproc/wkup_m3_rproc.c
> new file mode 100644
> index 0000000..58aeaf2
> --- /dev/null
> +++ b/drivers/remoteproc/wkup_m3_rproc.c
> @@ -0,0 +1,512 @@
> +/*
> + * AMx3 Wkup M3 Remote Processor driver
> + *
> + * Copyright (C) 2014 Texas Instruments, Inc.
> + *
> + * Dave Gerlach <[email-masked]>
> + *
> + * 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/platform_device.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <linux/elf.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/firmware.h>
> +#include <linux/remoteproc.h>
> +#include <linux/omap-mailbox.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/wkup_m3.h>
> +#include <linux/kthread.h>
> +#include "remoteproc_internal.h"
> +
> +#include <linux/platform_data/wkup_m3.h>
> +
> +#define WKUP_M3_WAKE_SRC_MASK		0xFF
> +
> +#define WKUP_M3_STATUS_RESP_SHIFT	16
> +#define WKUP_M3_STATUS_RESP_MASK	(0xffff << 16)
> +
> +#define WKUP_M3_FW_VERSION_SHIFT	0
> +#define WKUP_M3_FW_VERSION_MASK		0xffff
> +
> +/* AM33XX M3_TXEV_EOI register */
> +#define AM33XX_CONTROL_M3_TXEV_EOI	0x00
> +
> +#define AM33XX_M3_TXEV_ACK		(0x1 << 0)
> +#define AM33XX_M3_TXEV_ENABLE		(0x0 << 0)
> +
> +/* AM33XX IPC message registers */
> +#define AM33XX_CONTROL_IPC_MSG_REG0	0x04
> +#define AM33XX_CONTROL_IPC_MSG_REG1	0x08
> +#define AM33XX_CONTROL_IPC_MSG_REG2	0x0c
> +#define AM33XX_CONTROL_IPC_MSG_REG3	0x10
> +#define AM33XX_CONTROL_IPC_MSG_REG4	0x14
> +#define AM33XX_CONTROL_IPC_MSG_REG5	0x18
> +#define AM33XX_CONTROL_IPC_MSG_REG6	0x1c
> +#define AM33XX_CONTROL_IPC_MSG_REG7	0x20
> +
Is this driver going to be AM33xx specific ?

> +struct wkup_m3_rproc {
> +	struct rproc *rproc;
> +
> +	void * __iomem dev_table_va;
> +	void * __iomem ipc_mem_base;
> +	struct platform_device *pdev;
> +
> +	struct mbox_client mbox_client;
> +	struct mbox_chan *mbox;
> +	struct wkup_m3_ops *ops;
> +
> +	bool is_active;
> +};
> +
> +static struct wkup_m3_rproc *m3_rproc_static;
> +
> +static struct wkup_m3_wakeup_src wakeups[] = {
> +	{.irq_nr = 35,	.src = "USB0_PHY"},
> +	{.irq_nr = 36,	.src = "USB1_PHY"},
> +	{.irq_nr = 40,	.src = "I2C0"},
> +	{.irq_nr = 41,	.src = "RTC Timer"},
> +	{.irq_nr = 42,	.src = "RTC Alarm"},
> +	{.irq_nr = 43,	.src = "Timer0"},
> +	{.irq_nr = 44,	.src = "Timer1"},
> +	{.irq_nr = 45,	.src = "UART"},
> +	{.irq_nr = 46,	.src = "GPIO0"},
> +	{.irq_nr = 48,	.src = "MPU_WAKE"},
> +	{.irq_nr = 49,	.src = "WDT0"},
> +	{.irq_nr = 50,	.src = "WDT1"},
> +	{.irq_nr = 51,	.src = "ADC_TSC"},
> +	{.irq_nr = 0,	.src = "Unknown"},
> +};
> +
const ?

> +static void am33xx_txev_eoi(struct wkup_m3_rproc *m3_rproc)
> +{
> +	writel(AM33XX_M3_TXEV_ACK,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI);
> +}
> +
> +static void am33xx_txev_enable(struct wkup_m3_rproc *m3_rproc)
> +{
> +	writel(AM33XX_M3_TXEV_ENABLE,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI);
> +}
> +
> +static void wkup_m3_ctrl_ipc_write(struct wkup_m3_rproc *m3_rproc,
> +				   struct wkup_m3_ipc_regs *ipc_regs)
> +{
> +	writel(ipc_regs->reg0,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG0);
> +	writel(ipc_regs->reg1,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG1);
> +	writel(ipc_regs->reg2,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG2);
> +	writel(ipc_regs->reg3,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG3);
> +	writel(ipc_regs->reg4,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG4);
> +	writel(ipc_regs->reg5,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG5);
> +	writel(ipc_regs->reg6,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG6);
> +	writel(ipc_regs->reg7,
> +	       m3_rproc->ipc_mem_base + AM33XX_CONTROL_IPC_MSG_REG7);
> +}
> +
> +static void wkup_m3_ctrl_ipc_read(struct wkup_m3_rproc *m3_rproc,
> +				  struct wkup_m3_ipc_regs *ipc_regs)
> +{
> +	ipc_regs->reg0 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG0);
> +	ipc_regs->reg1 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG1);
> +	ipc_regs->reg2 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG2);
> +	ipc_regs->reg3 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG3);
> +	ipc_regs->reg4 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG4);
> +	ipc_regs->reg5 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG5);
> +	ipc_regs->reg6 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG6);
> +	ipc_regs->reg7 = readl(m3_rproc->ipc_mem_base
> +			       + AM33XX_CONTROL_IPC_MSG_REG7);
> +}
> +
> +static irqreturn_t wkup_m3_txev_handler(int irq, void *unused)
> +{
> +	am33xx_txev_eoi(m3_rproc_static);
> +
> +	if (m3_rproc_static->ops && m3_rproc_static->ops->txev_handler)
> +		m3_rproc_static->ops->txev_handler();
> +
> +	am33xx_txev_enable(m3_rproc_static);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/**
> + * wkup_m3_fw_version_clear - Clear FW version from ipc regs
> + *
> + * Invalidate M3 firmware version before hardreset.
> + * Write invalid version in lower 4 nibbles of parameter
> + * register (ipc_regs + 0x8).
> + */
> +
> +static void wkup_m3_fw_version_clear(void)
> +{
> +	struct wkup_m3_ipc_regs ipc_regs;
> +
> +	wkup_m3_ctrl_ipc_read(m3_rproc_static, &ipc_regs);
> +	ipc_regs.reg2 &= 0xFFFF0000;
Probably define a macro and use it.
> +	wkup_m3_ctrl_ipc_write(m3_rproc_static, &ipc_regs);
> +}
> +
> +static void wkup_m3_mbox_callback(struct mbox_client *client, void *data)
> +{
> +	omap_mbox_disable_irq(m3_rproc_static->mbox, IRQ_RX);
> +}
> +
> +static int wkup_m3_rproc_start(struct rproc *rproc)
> +{
> +	struct wkup_m3_rproc *m3_rproc = rproc->priv;
> +	struct platform_device *pdev = m3_rproc->pdev;
> +	struct device *dev = &pdev->dev;
> +	struct wkup_m3_platform_data *pdata = dev->platform_data;
> +	int ret;
> +
> +	wkup_m3_fw_version_clear();
> +
> +	if (pdata && pdata->deassert_reset) {
> +		ret = pdata->deassert_reset(pdev, pdata->reset_name);
> +		if (ret) {
> +			dev_err(dev, "Unable to reset wkup_m3!\n");
> +			return -ENODEV;
> +		}
> +	} else {
> +		dev_err(dev, "Platform data missing deassert_reset!\n");
> +		return -ENODEV;
> +	}
> +
> +	m3_rproc->mbox_client.dev = dev;
> +	m3_rproc->mbox_client.tx_done = NULL;
> +	m3_rproc->mbox_client.rx_callback = wkup_m3_mbox_callback;
> +	m3_rproc->mbox_client.tx_block = false;
> +	m3_rproc->mbox_client.knows_txdone = false;
> +
> +	m3_rproc->mbox = mbox_request_channel(&m3_rproc->mbox_client);
> +
> +	if (IS_ERR(m3_rproc->mbox)) {
> +		dev_err(dev, "IPC Request for A8->M3 Channel failed!\n");
> +		ret = PTR_ERR(m3_rproc->mbox);
> +		m3_rproc->mbox = NULL;
> +		return ret;
> +	}
> +
> +	if (m3_rproc_static->ops && m3_rproc_static->ops->rproc_ready)
> +		m3_rproc_static->ops->rproc_ready();
> +
> +	m3_rproc_static->is_active = 1;
> +
> +	return 0;
> +}
> +
> +
> +static int wkup_m3_rproc_stop(struct rproc *rproc)
> +{
> +	return 0;
> +}
> +
> +static void wkup_m3_rproc_kick(struct rproc *rproc, int vqid)
> +{
> +}
> +
> +static struct rproc_ops wkup_m3_rproc_ops = {
> +	.start		= wkup_m3_rproc_start,
> +	.stop		= wkup_m3_rproc_stop,
> +	.kick		= wkup_m3_rproc_kick,
> +};
> +
> +/* Public Functions */
> +
> +/**
> + * wkup_m3_set_ops - Set callbacks for user of rproc
> + * @ops - struct wkup_m3_ops *
> + *
> + * Registers callbacks to wkup_m3 to be invoked after rproc is ready to use
> + * and after an interrupt is handled.
> + */
> +void wkup_m3_set_ops(struct wkup_m3_ops *ops)
> +{
> +	m3_rproc_static->ops = ops;
> +
> +	if (m3_rproc_static->is_active && m3_rproc_static->ops &&
> +	    m3_rproc_static->ops->rproc_ready)
> +		m3_rproc_static->ops->rproc_ready();
> +}
> +
> +/**
> + * wkup_m3_ping - Send a dummy msg to wkup_m3 to tell to to check IPC regs
> + *
> + * Returns the result of sending mbox msg or -EIO if no mbox handle is present
> + */
> +int wkup_m3_ping(void)
> +{
> +	int ret;
> +	mbox_msg_t dummy_msg = 0;
> +
> +	if (!m3_rproc_static->mbox) {
> +		dev_err(&m3_rproc_static->pdev->dev,
> +			"No IPC channel to communicate with wkup_m3!\n");
> +		return -EIO;
> +	}
> +
> +	/*
> +	 * Write a dummy message to the mailbox in order to trigger the RX
> +	 * interrupt to alert the M3 that data is available in the IPC
> +	 * registers. We must enable the IRQ here and disable it after in
> +	 * the RX callback to avoid multiple interrupts being received
> +	 * by the CM3.
> +	 */
> +	omap_mbox_enable_irq(m3_rproc_static->mbox, IRQ_RX);
> +	ret = mbox_send_message(m3_rproc_static->mbox, (void *)dummy_msg);
> +
> +	if (ret < 0) {
> +		pr_err("%s: mbox_send_message() failed: %d\n", __func__, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * wkup_m3_wake_src - Get the wakeup source info passed from wkup_m3
> + * @wkup_m3_wakeup: struct wkup_m3_wakeup_src * gets assigned the
> + *		    wakeup src value
> + */
> +void wkup_m3_wake_src(struct wkup_m3_wakeup_src *wkup_m3_wakeup)
> +{
> +	struct wkup_m3_ipc_regs ipc_regs;
> +	unsigned int wakeup_src_idx;
> +	int j;
> +
> +	wkup_m3_ctrl_ipc_read(m3_rproc_static, &ipc_regs);
> +
> +	wakeup_src_idx = ipc_regs.reg6 & WKUP_M3_WAKE_SRC_MASK;
> +
> +	for (j = 0; j < ARRAY_SIZE(wakeups)-1; j++) {
> +		if (wakeups[j].irq_nr == wakeup_src_idx) {
> +			*wkup_m3_wakeup = wakeups[j];
> +			return;
> +		}
> +	}
> +	*wkup_m3_wakeup = wakeups[j];
> +}
> +
> +/**
> + * wkup_m3_pm_status - Return the status code from wkup_m3 after sleep event
> + *
> + * Returns an error code that indicates whether or not the dsired sleep
> + * action was a success or not.
> + */
> +int wkup_m3_pm_status(void)
> +{
> +	unsigned int i;
> +	struct wkup_m3_ipc_regs ipc_regs;
> +
> +	wkup_m3_ctrl_ipc_read(m3_rproc_static, &ipc_regs);
> +
> +	i = WKUP_M3_STATUS_RESP_MASK & ipc_regs.reg1;
> +	i >>= __ffs(WKUP_M3_STATUS_RESP_MASK);
> +
> +	return i;
> +}
> +
> +/**
> + * wkup_m3_fw_version_read - Return the fw version given by the wkup_m3
> + *
> + * After boot the fw version should be read to ensure it is compatible.
> + */
> +int wkup_m3_fw_version_read(void)
> +{
> +	struct wkup_m3_ipc_regs ipc_regs;
> +
> +	wkup_m3_ctrl_ipc_read(m3_rproc_static, &ipc_regs);
> +
> +	return ipc_regs.reg2 & WKUP_M3_FW_VERSION_MASK;
> +}
> +
> +/**
> + * wkup_m3_set_cmd - write contents of struct to ipc regs
> + * @ipc_regs: struct wkup_m3_ipc_regs *
> + */
> +void wkup_m3_set_cmd(struct wkup_m3_ipc_regs *ipc_regs)
> +{
> +	wkup_m3_ctrl_ipc_write(m3_rproc_static, ipc_regs);
> +}
> +
> +static void wkup_m3_rproc_loader_thread(struct rproc *rproc)
> +{
> +	struct wkup_m3_rproc *m3_rproc = rproc->priv;
> +	struct device *dev = &m3_rproc->pdev->dev;
> +	int ret;
> +
> +	wait_for_completion(&rproc->firmware_loading_complete);
> +
> +	ret = rproc_boot(rproc);
> +	if (ret)
> +		dev_err(dev, "rproc_boot failed\n");
> +
> +	do_exit(0);
> +}
> +
> +static int wkup_m3_rproc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = pdev->dev.of_node;
> +	struct wkup_m3_rproc *m3_rproc;
> +	struct rproc *rproc;
> +	int irq, ret;
> +	struct resource *res;
> +	struct task_struct *task;
> +	const char *mbox_name;
> +
> +	pm_runtime_enable(&pdev->dev);
> +
> +	ret = pm_runtime_get_sync(&pdev->dev);
> +	if (IS_ERR_VALUE(ret)) {
> +		dev_err(&pdev->dev, "pm_runtime_get_sync() failed\n");
> +		return ret;
> +	}
> +
> +	rproc = rproc_alloc(dev, "wkup_m3", &wkup_m3_rproc_ops,
> +			    "am335x-pm-firmware.elf", sizeof(*m3_rproc));
> +	if (!rproc)
> +		return -ENOMEM;
> +
> +	m3_rproc = rproc->priv;
> +	m3_rproc->rproc = rproc;
> +	m3_rproc->pdev = pdev;
> +
> +	m3_rproc_static = m3_rproc;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (!irq) {
> +		dev_err(&pdev->dev, "no irq resource\n");
> +		ret = -ENXIO;
> +		goto err;
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ipc_regs");
> +	if (!res) {
> +		dev_err(&pdev->dev, "no memory resource for ipc\n");
> +		ret = -ENXIO;
> +		goto err;
> +	}
> +
> +	m3_rproc->ipc_mem_base = devm_request_and_ioremap(dev, res);
> +	if (!m3_rproc->ipc_mem_base) {
> +		dev_err(dev, "could not ioremap ipc_mem\n");
> +		ret = -EADDRNOTAVAIL;
> +		goto err;
> +	}
> +
> +	ret = devm_request_irq(dev, irq, wkup_m3_txev_handler,
> +			       IRQF_DISABLED, "wkup_m3_txev", m3_rproc);
> +	if (ret) {
> +		dev_err(dev, "request_irq failed\n");
> +		goto err;
> +	}
> +
> +	/* Get mbox name from device tree node */
> +	ret = of_property_read_string(np, "mbox-names", &mbox_name);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Unable to get mbox name from dt node: %d\n",
> +			ret);
> +			goto err;
> +	};
> +
> +	m3_rproc->mbox_client.chan_name = mbox_name;
> +
> +	/* Register as a remoteproc device */
> +	ret = rproc_add(rproc);
> +	if (ret) {
> +		dev_err(dev, "rproc_add failed\n");
> +		goto err;
> +	}
> +
> +	/*
> +	 * Wait for firmware loading completion in a thread so we
> +	 * can boot the wkup_m3 as soon as it's ready without holding
> +	 * up kernel boot
> +	 */
> +	task = kthread_run((void *)wkup_m3_rproc_loader_thread, rproc,
> +			   "wkup_m3_rproc_loader");
> +
> +	if (IS_ERR(task)) {
> +		dev_err(dev, "can't create rproc_loader thread\n");
> +		goto err;
> +	}
> +
> +	return 0;
> +
> +err:
> +	rproc_put(rproc);
pm_runtime_put_sync() ?
> +	return ret;
> +}
> +
> +static int wkup_m3_rproc_remove(struct platform_device *pdev)
> +{
> +	struct rproc *rproc = platform_get_drvdata(pdev);
> +
> +	rproc_del(rproc);
> +	rproc_put(rproc);
> +
Here too ?
> +	return 0;
> +}
> +
> +static int wkup_m3_rpm_suspend(struct device *dev)
> +{
> +	return -EBUSY;
> +}
> +
> +static int wkup_m3_rpm_resume(struct device *dev)
> +{
> +	return 0;
> +}
> +
If you are not doing any meaningfull in suspend/resume hooks,
why are you even registering them ?

> +static const struct dev_pm_ops wkup_m3_rproc_pm_ops = {
> +	SET_RUNTIME_PM_OPS(wkup_m3_rpm_suspend, wkup_m3_rpm_resume, NULL)
> +};
> +
> +static const struct of_device_id wkup_m3_rproc_of_match[] = {
> +	{ .compatible = "ti,am3353-wkup-m3", .data = NULL, },
> +	{},
> +};
> +
> +static struct platform_driver wkup_m3_rproc_driver = {
> +	.probe = wkup_m3_rproc_probe,
> +	.remove = wkup_m3_rproc_remove,
> +	.driver = {
> +		.name = "wkup_m3",
> +		.owner = THIS_MODULE,
> +		.of_match_table = wkup_m3_rproc_of_match,
> +		.pm = &wkup_m3_rproc_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(wkup_m3_rproc_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("wkup m3 remote processor control driver");
> diff --git a/include/linux/wkup_m3.h b/include/linux/wkup_m3.h
> new file mode 100644
> index 0000000..1a2237f
> --- /dev/null
> +++ b/include/linux/wkup_m3.h
> @@ -0,0 +1,71 @@
> +/*
> + * TI Wakeup M3 Power Management Routines
> + *
> + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
> + * Dave Gerlach <[email-masked]>
> + *
> + * 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.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _LINUX_WKUP_M3_H
> +#define _LINUX_WKUP_M3_H
> +
> +/**
> + * struct wkup_m3_ops - Callbacks for allowing pm code to interact with wkup_m3.
> + *
> + * @txev_handler: Callback to allow pm code to react to response from wkup_m3
> + *		  after pinging it using wkup_m3_ping.
> + *
> + * @firmware_loaded: Callback invoked when the firmware has been loaded to the
> + *		     m3 to allow the pm code to enable suspend/resume ops.
> + */
> +
> +struct wkup_m3_ops {
> +	void (*txev_handler)(void);
> +	void (*rproc_ready)(void);
> +};
> +
> +struct wkup_m3_wakeup_src {
> +	int irq_nr;
> +	char src[10];
> +};
> +
> +struct wkup_m3_ipc_regs {
> +	u32 reg0;
> +	u32 reg1;
> +	u32 reg2;
> +	u32 reg3;
> +	u32 reg4;
> +	u32 reg5;
> +	u32 reg6;
> +	u32 reg7;
> +};
> +
> +#ifdef CONFIG_WKUP_M3_RPROC
> +int wkup_m3_prepare(void);
> +void wkup_m3_set_ops(struct wkup_m3_ops *ops);
> +int wkup_m3_ping(void);
> +void wkup_m3_wake_src(struct wkup_m3_wakeup_src *wakeup_src);
> +int wkup_m3_pm_status(void);
> +int wkup_m3_is_valid(void);
> +int wkup_m3_fw_version_read(void);
> +void wkup_m3_set_cmd(struct wkup_m3_ipc_regs *ipc_regs);
> +
> +#else
> +
> +int wkup_m3_prepare(void) { return -EINVAL; }
> +void wkup_m3_set_ops(struct wkup_m3_ops *ops) { }
> +int wkup_m3_ping(void) { return -EINVAL }
> +void wkup_m3_wake_src(struct wkup_m3_wakeup_src *wakeup_src) { }
> +int wkup_m3_pm_status(void) { return -1; }
> +int wkup_m3_fw_version_read(void) { return -1; }
> +void wkup_m3_set_cmd(struct wkup_m3_ipc_regs *ipc_regs) { }

Mark all of above in else as static inline.

> +#endif /* CONFIG_WKUP_M3_RPROC */
> +#endif /* _LINUX_WKUP_M3_H */
>