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

From: [email-masked] (Dave Gerlach)
Date: Mon, 14 Jul 2014 16:09:52 -0500

Suman,

On 07/14/2014 02:07 PM, Suman Anna wrote:
> Hi Dave,
>
> I have a few more comments in addition to Santosh's..
>
> On 07/14/2014 09:54 AM, Santosh Shilimkar wrote:
>> 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
>
> typo - coprocessor*

Whoops thanks.

>
>>> +	  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>
>
> Do you require this header?

No, seems I forgot to remove it after moving to common remoteproc_elf_ops.

>
>>> +#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"
>
> Suggest moving the internal header to after including the
> standard headers..

Ok.

>
>>> +
>>> +#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
>
> How about using a macro for these, especially given that the AM43xx has
> a bit more registers.

Yeah after thinking about it I will clean this up a bit. More explanation in 
later comment.

>
>>> +
>> 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"},
>>> +};
>
> Is this table going to be same for AM43xx? If not, it is better to store
> this as match data, so that a different table can easily be plugged in
> based on compatible string.

The table actually is the same for am43xx with the addition of a few wake 
sources that aren't possible on am335x, so it'll work like this.

>
>>> +
>> 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);
>
> How about defining a static inline function for the read and write
> operations?

Again, I plan to clean up these reads and writes now. More explanation in a 
later comment.

>
>>> +}
>>> +
>>> +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;
>>> +	}
>
> You don't need a runtime check for this, check once in probe, this ops
> is essential right?

Yes you are right, better that way.

>
>>> +
>>> +	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);
>>> +
> nit, no need of an additional blank line

Ok.

>
>>> +	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;
>
> Any reason this is a stub, don't you need to assert the reset in stop?

Well, at this point I don't think there is any reason you would want to stop the 
wkup_m3, it will certainly cause issues with PM. That would be the most 
appropriate action here though.

>
>>> +}
>>> +
>>> +static void wkup_m3_rproc_kick(struct rproc *rproc, int vqid)
>>> +{
>>> +}
>
> If you can remove this empty stub, please do so. I do not think we will
> be using virtio for communicating with the WkupM3.

We don't need it, Ill remove it.

>
>>> +
>>> +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);
>>> +
> nit, no need of an additional blank line

Ok.

>
>>> +	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);
>
> Do you need to read back all the registers, given that this is a local
> structure anyway?

Well, at least one of the registers must be read back (reg1) in order to get the 
PM status value returned by the wkup_m3. The ipc read/write functions had been 
rewritten to be more "generic" in order to avoid exposing a bunch of specific 
APIs from the control module. The reads/writes are all internal to the driver 
now though so it probably makes sense to do away with that entirely now and be 
more specific in what we read and write.

>
>>> +
>>> +	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;
>>> +	}
>
> Colocate this to the same place as the request_irq.

Ok.

>
>>> +
>>> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ipc_regs");
>>> +	if (!res) {
>
> No need to check for error, the devm function following this should take
> care of any errors.
>
>>> +		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);
>
> Is some one else doing an ioremap of this space, otherwise
> devm_ioremap_resource is preferred.

I will update driver to do it this way, was unfamiliar with this approach.

>
>>> +	if (!m3_rproc->ipc_mem_base) {
>>> +		dev_err(dev, "could not ioremap ipc_mem\n");
>>> +		ret = -EADDRNOTAVAIL;
>>> +		goto err;
>>> +	}
>
> Don't you need to be retrieving umem and dmem?

We don't need to do that here as remoteproc handles it for us behind the scenes. 
They are left in the DT as they had already been added and to keep the address 
space consistent.

>
>
>>> +
>>> +	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);
>
> Need to reset m3_rproc_static?

Yes I need to take care of that.

>
>>> +
>> 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
>
> Suggest adding for AMx3x SoCs

Good idea.

>
>>> + *
>>> + * 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.
>
> firmware_loaded ops does not exist

Ah yes, seems I renamed the function pointer but failed to update the comment.

>
>>> + */
>>> +
>>> +struct wkup_m3_ops {
>>> +	void (*txev_handler)(void);
>>> +	void (*rproc_ready)(void);
>>> +};
>>> +
>>> +struct wkup_m3_wakeup_src {
>>> +	int irq_nr;
>>> +	char src[10];
>
> What is the @src used for, debug? Don't see anywhere this is getting used.

It is used to provide a string that names the wakeup source, the table is 
defined at the top of wkup_m3_rproc.c in this patch.

Thanks for the comments.

Regards,
Dave

>
> regards
> Suman
>
>>> +};
>>> +
>>> +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 */
>>>
>>
>