[v7,01/16] remoteproc: st_slim_rproc: add a slimcore rproc driver

Commit Message

Peter Griffin Aug. 1, 2016, 5:10 p.m. UTC

slim core is used as a basis for many IPs in the STi
chipsets such as fdma and demux. To avoid duplicating
the elf loading code in each device driver a slim
rproc driver has been created.

This driver is designed to be used by other device drivers
such as fdma, or demux whose IP is based around a slim core.
The device driver can call slim_rproc_alloc() to allocate
a slim rproc and slim_rproc_put() when finished.

This driver takes care of ioremapping the slim
registers (dmem, imem, slimcore, peripherals), whose offsets
and sizes can change between IP's. It also obtains and enables
any clocks used by the device. This approach avoids having
a double mapping of the registers as slim_rproc does not register
its own platform device. It also maps well to device tree
abstraction as it allows us to have one dt node for the whole
device.

All of the generic rproc elf loading code can be reused, and
we provide start() stop() hooks to start and stop the slim
core once the firmware has been loaded. This has been tested
successfully with fdma driver.

Signed-off-by: Peter Griffin <[e-mail]>
---
 drivers/remoteproc/Kconfig               |   7 +
 drivers/remoteproc/Makefile              |   1 +
 drivers/remoteproc/st_slim_rproc.c       | 376 +++++++++++++++++++++++++++++++
 include/linux/remoteproc/st_slim_rproc.h |  53 +++++
 4 files changed, 437 insertions(+)
 create mode 100644 drivers/remoteproc/st_slim_rproc.c
 create mode 100644 include/linux/remoteproc/st_slim_rproc.h

Comments

Bjorn Andersson Aug. 10, 2016, 7:29 p.m. UTC | #1

On Mon 01 Aug 10:10 PDT 2016, Peter Griffin wrote:

Sorry for the slow response, but I have a few more (small) concerns.

[..]
> diff --git a/drivers/remoteproc/st_slim_rproc.c b/drivers/remoteproc/st_slim_rproc.c
[..]
> +static int slim_rproc_start(struct rproc *rproc)
> +{
> +	struct device *dev = &rproc->dev;
> +	struct st_slim_rproc *slim_rproc = rproc->priv;
> +	unsigned long hw_id, hw_ver, fw_rev;
> +	u32 val;
> +	int ret;
> +
> +	ret = slim_clk_enable(slim_rproc);
> +	if (ret) {
> +		dev_err(dev, "Failed to enable clocks\n");
> +		goto err_clk;

Nit. just return ret here and have a static "return 0" at the bottom.

> +	}
> +
> +	/* disable CPU pipeline clock & reset cpu pipeline */
> +	val = SLIM_CLK_GATE_DIS | SLIM_CLK_GATE_RESET;
> +	writel(val, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
> +
> +	/* disable SLIM core STBus sync */
> +	writel(SLIM_STBUS_SYNC_DIS, slim_rproc->peri + SLIM_STBUS_SYNC_OFST);
> +
> +	/* enable cpu pipeline clock */
> +	writel(!SLIM_CLK_GATE_DIS,
> +		slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
> +
> +	/* clear int & cmd mailbox */
> +	writel(~0U, slim_rproc->peri + SLIM_INT_CLR_OFST);
> +	writel(~0U, slim_rproc->peri + SLIM_CMD_CLR_OFST);
> +
> +	/* enable all channels cmd & int */
> +	writel(~0U, slim_rproc->peri + SLIM_INT_MASK_OFST);
> +	writel(~0U, slim_rproc->peri + SLIM_CMD_MASK_OFST);
> +
> +	/* enable cpu */
> +	writel(SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
> +
> +	hw_id = readl_relaxed(slim_rproc->slimcore + SLIM_ID_OFST);
> +	hw_ver = readl_relaxed(slim_rproc->slimcore + SLIM_VER_OFST);
> +
> +	fw_rev = readl(slim_rproc->mem[SLIM_DMEM].cpu_addr +
> +			SLIM_REV_ID_OFST);
> +
> +	dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
> +		 SLIM_REV_ID_MAJ(fw_rev), SLIM_REV_ID_MIN(fw_rev),
> +		 hw_id, hw_ver);
> +
> +err_clk:
> +	return ret;
> +}
> +
> +static int slim_rproc_stop(struct rproc *rproc)
> +{
> +	struct st_slim_rproc *slim_rproc = rproc->priv;
> +	u32 val;
> +
> +	/* mask all (cmd & int) channels */
> +	writel(0UL, slim_rproc->peri + SLIM_INT_MASK_OFST);
> +	writel(0UL, slim_rproc->peri + SLIM_CMD_MASK_OFST);
> +
> +	/* disable cpu pipeline clock */
> +	writel(SLIM_CLK_GATE_DIS
> +		, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);

Odd placement of ','

> +
> +	writel(!SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
> +
> +	val = readl(slim_rproc->slimcore + SLIM_EN_OFST);
> +	if (val & SLIM_EN_RUN)
> +		dev_warn(&rproc->dev, "Failed to disable SLIM");
> +
> +	slim_clk_disable(slim_rproc);
> +
> +	dev_dbg(&rproc->dev, "slim stopped\n");
> +
> +	return 0;
> +}
> +
> +static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
> +{
> +	struct st_slim_rproc *slim_rproc = rproc->priv;
> +	void *va = NULL;
> +	int i;
> +
> +	for (i = 0; i < SLIM_MEM_MAX; i++) {
> +		if (da != slim_rproc->mem[i].bus_addr)
> +			continue;

Are you sure you want to enforce this being called with da == base? (I'm
not totally against it).

But you should probably double check that len is <= mem[i].size.

> +		/* __force to make sparse happy with type conversion */
> +		va = (__force void *)slim_rproc->mem[i].cpu_addr;
> +		break;
> +	}
> +
> +	dev_dbg(&rproc->dev, "%s: da = 0x%llx len = 0x%x va = 0x%p\n",
> +		__func__, da, len, va);
> +
> +	return va;
> +}
> +
> +static struct rproc_ops slim_rproc_ops = {
> +	.start		= slim_rproc_start,
> +	.stop		= slim_rproc_stop,
> +	.da_to_va       = slim_rproc_da_to_va,
> +};
> +
> +/**
> + * Firmware handler operations: sanity, boot address, load ...
> + */
> +
> +static struct resource_table empty_rsc_tbl = {
> +	.ver = 1,
> +	.num = 0,
> +};
> +
> +static struct resource_table *slim_rproc_find_rsc_table(struct rproc *rproc,
> +					       const struct firmware *fw,
> +					       int *tablesz)
> +{
> +	if (!fw)
> +		return NULL;

I consider it a BUG in the core to get here with fw == NULL, so please
drop this.

> +
> +	*tablesz = sizeof(empty_rsc_tbl);
> +	return &empty_rsc_tbl;
> +}
> +
> +static struct resource_table *slim_rproc_find_loaded_rsc_table(struct rproc *rproc,
> +						      const struct firmware *fw)
> +{
> +	if (!fw)
> +		return NULL;
> +

fw can't be NULL, so please drop this check.

> +	return &empty_rsc_tbl;

This function is supposed to return a pointer to the resource table as
it appears in the space of the running firmware, so that any vring
updates etc are visible to the remote.

As your firmware doesn't do this you should return NULL here, rather
than a pointer back to the fake resource table.

But rproc_find_loaded_rsc_table() will do the same if you omit the
reference in the fw_ops struct, so just make that NULL instead.

> +}
> +
> +static struct rproc_fw_ops slim_rproc_fw_ops = {
> +	.find_rsc_table = slim_rproc_find_rsc_table,
> +	.find_loaded_rsc_table = slim_rproc_find_loaded_rsc_table,
> +};
> +
> +
> +/**
> + * slim_rproc_alloc() - allocate and initialise slim rproc
> + * @pdev: Pointer to the platform_device struct
> + * @fw_name: Name of firmware for rproc to use
> + *
> + * Function for allocating and initialising a slim rproc for use by
> + * device drivers whose IP is based around the slim slim core. It
> + * obtains and enables any clocks required by the slim core and also
> + * ioremaps the various IO.
> + *
> + * Returns st_slim_rproc pointer or PTR_ERR() on error.
> + */
> +
> +struct st_slim_rproc *slim_rproc_alloc(struct platform_device *pdev,
> +				char *fw_name)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct st_slim_rproc *slim_rproc;
> +	struct device_node *np = dev->of_node;
> +	struct rproc *rproc;
> +	struct resource *res;
> +	int err, i;
> +	const struct rproc_fw_ops *elf_ops;
> +
> +	if (WARN_ON(!np || !fw_name))
> +		return ERR_PTR(-EINVAL);
> +
> +	if (!of_device_is_compatible(np, "st,slim-rproc"))
> +		return ERR_PTR(-EINVAL);
> +
> +	rproc = rproc_alloc(dev, np->name, &slim_rproc_ops,
> +			fw_name, sizeof(*slim_rproc));
> +	if (!rproc)
> +		return ERR_PTR(-ENOMEM);
> +
> +	rproc->has_iommu = false;
> +
> +	slim_rproc = rproc->priv;
> +	slim_rproc->rproc = rproc;
> +
> +	elf_ops = rproc->fw_ops;
> +	/* Use some generic elf ops */
> +	slim_rproc_fw_ops.load = elf_ops->load;
> +	slim_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
> +
> +	rproc->fw_ops = &slim_rproc_fw_ops;
> +
> +	/* get imem and dmem */
> +	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
> +
> +		res = platform_get_resource_byname
> +			(pdev, IORESOURCE_MEM, mem_names[i]);

This is an odd line breakage.

> +
> +		slim_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
> +		if (IS_ERR(slim_rproc->mem[i].cpu_addr)) {
> +			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
> +			err = PTR_ERR(slim_rproc->mem[i].cpu_addr);
> +			goto err;
> +		}
> +		slim_rproc->mem[i].bus_addr = res->start;
> +		slim_rproc->mem[i].size = resource_size(res);
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
> +
> +	slim_rproc->slimcore = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(slim_rproc->slimcore)) {
> +		dev_err(&pdev->dev,
> +			"devm_ioremap_resource failed for slimcore\n");
> +		err = PTR_ERR(slim_rproc->slimcore);
> +		goto err;
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
> +
> +	slim_rproc->peri = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(slim_rproc->peri)) {
> +		dev_err(&pdev->dev, "devm_ioremap_resource failed for peri\n");
> +		err = PTR_ERR(slim_rproc->peri);
> +		goto err;
> +	}
> +
> +	err = slim_clk_get(slim_rproc, dev);
> +	if (err)
> +		goto err;
> +
> +	/* Register as a remoteproc device */
> +	err = rproc_add(rproc);
> +	if (err) {
> +		dev_err(dev, "registration of slim remoteproc failed\n");
> +		goto err_clk;
> +	}
> +
> +	return slim_rproc;
> +
> +err_clk:
> +	for (i = 0; i < SLIM_MAX_CLK && slim_rproc->clks[i]; i++)
> +		clk_put(slim_rproc->clks[i]);

Is there any chance to could acquire these clocks by name instead of
just picking up 4 "random" clocks from the DT node?

You are generally supposed to use clock-names and could then use
devm_clk_get() instead...

> +err:
> +	rproc_put(rproc);
> +	return ERR_PTR(err);
> +}
> +EXPORT_SYMBOL(slim_rproc_alloc);
> +
> +/**
> +  * slim_rproc_put() - put slim rproc resources
> +  * @slim_rproc: Pointer to the st_slim_rproc struct
> +  *
> +  * Function for calling respective _put() functions on
> +  * slim_rproc resources.
> +  *
> +  */
> +void slim_rproc_put(struct st_slim_rproc *slim_rproc)
> +{
> +	int clk;
> +
> +	if (!slim_rproc)
> +		return;
> +
> +	for (clk = 0; clk < SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
> +		clk_put(slim_rproc->clks[clk]);
> +

You need to rproc_del() here before calling rproc_put().

> +	rproc_put(slim_rproc->rproc);
> +}
> +EXPORT_SYMBOL(slim_rproc_put);
> +
> +MODULE_AUTHOR("Peter Griffin");
> +MODULE_DESCRIPTION("STMicroelectronics SLIM rproc driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/remoteproc/st_slim_rproc.h b/include/linux/remoteproc/st_slim_rproc.h
> new file mode 100644
> index 0000000..c300b3e
> --- /dev/null
> +++ b/include/linux/remoteproc/st_slim_rproc.h
> @@ -0,0 +1,53 @@
> +/*
> + * st_slim_rproc.h
> + *
> + * Copyright (C) 2016 STMicroelectronics
> + * Author: Peter Griffin <[e-mail]>
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +#ifndef _ST_SLIM_H
> +#define _ST_SLIM_H
> +
> +#define SLIM_MEM_MAX 2
> +#define SLIM_MAX_CLK 4
> +
> +enum {
> +	SLIM_DMEM,
> +	SLIM_IMEM,
> +};
> +
> +/**
> + * struct slim_mem - slim internal memory structure
> + * @cpu_addr: MPU virtual address of the memory region
> + * @bus_addr: Bus address used to access the memory region
> + * @size: Size of the memory region
> + */
> +struct slim_mem {
> +	void __iomem *cpu_addr;
> +	phys_addr_t bus_addr;
> +	size_t size;
> +};
> +

With things like slimbus being worked on I don't think it's appropriate
to introduce public constants named SLIM_* or slim_*. Please rename
these ST_SLIM_* and st_slim_*

> +/**
> + * struct st_slim_rproc - SLIM slim core
> + * @rproc: rproc handle
> + * @mem: slim memory information
> + * @slimcore: slim slimcore regs
> + * @peri: slim peripheral regs
> + * @clks: slim clocks
> + */
> +struct st_slim_rproc {
> +	struct rproc *rproc;
> +	struct slim_mem mem[SLIM_MEM_MAX];
> +	void __iomem *slimcore;
> +	void __iomem *peri;
> +
> +	/* st_slim_rproc private */
> +	struct clk *clks[SLIM_MAX_CLK];
> +};
> +
> +struct st_slim_rproc *slim_rproc_alloc(struct platform_device *pdev,
> +					char *fw_name);
> +void slim_rproc_put(struct st_slim_rproc *slim_rproc);
> +
> +#endif

Regards,
Bjorn

Peter Griffin Aug. 25, 2016, 4:41 p.m. UTC | #2

Hi Bjorn,

On Wed, 10 Aug 2016, Bjorn Andersson wrote:

> On Mon 01 Aug 10:10 PDT 2016, Peter Griffin wrote:
> 
> Sorry for the slow response, but I have a few more (small) concerns.

No problem, thanks for reviewing. Equally I've been away on holiday last 3
weeks, so sorry about my delay as well :)
> 
> [..]
> > diff --git a/drivers/remoteproc/st_slim_rproc.c b/drivers/remoteproc/st_slim_rproc.c
> [..]
> > +static int slim_rproc_start(struct rproc *rproc)
> > +{
> > +	struct device *dev = &rproc->dev;
> > +	struct st_slim_rproc *slim_rproc = rproc->priv;
> > +	unsigned long hw_id, hw_ver, fw_rev;
> > +	u32 val;
> > +	int ret;
> > +
> > +	ret = slim_clk_enable(slim_rproc);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to enable clocks\n");
> > +		goto err_clk;
> 
> Nit. just return ret here and have a static "return 0" at the bottom.

Will fix.

> 
> > +	}
> > +
> > +	/* disable CPU pipeline clock & reset cpu pipeline */
> > +	val = SLIM_CLK_GATE_DIS | SLIM_CLK_GATE_RESET;
> > +	writel(val, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
> > +
> > +	/* disable SLIM core STBus sync */
> > +	writel(SLIM_STBUS_SYNC_DIS, slim_rproc->peri + SLIM_STBUS_SYNC_OFST);
> > +
> > +	/* enable cpu pipeline clock */
> > +	writel(!SLIM_CLK_GATE_DIS,
> > +		slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
> > +
> > +	/* clear int & cmd mailbox */
> > +	writel(~0U, slim_rproc->peri + SLIM_INT_CLR_OFST);
> > +	writel(~0U, slim_rproc->peri + SLIM_CMD_CLR_OFST);
> > +
> > +	/* enable all channels cmd & int */
> > +	writel(~0U, slim_rproc->peri + SLIM_INT_MASK_OFST);
> > +	writel(~0U, slim_rproc->peri + SLIM_CMD_MASK_OFST);
> > +
> > +	/* enable cpu */
> > +	writel(SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
> > +
> > +	hw_id = readl_relaxed(slim_rproc->slimcore + SLIM_ID_OFST);
> > +	hw_ver = readl_relaxed(slim_rproc->slimcore + SLIM_VER_OFST);
> > +
> > +	fw_rev = readl(slim_rproc->mem[SLIM_DMEM].cpu_addr +
> > +			SLIM_REV_ID_OFST);
> > +
> > +	dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
> > +		 SLIM_REV_ID_MAJ(fw_rev), SLIM_REV_ID_MIN(fw_rev),
> > +		 hw_id, hw_ver);
> > +
> > +err_clk:
> > +	return ret;
> > +}
> > +
> > +static int slim_rproc_stop(struct rproc *rproc)
> > +{
> > +	struct st_slim_rproc *slim_rproc = rproc->priv;
> > +	u32 val;
> > +
> > +	/* mask all (cmd & int) channels */
> > +	writel(0UL, slim_rproc->peri + SLIM_INT_MASK_OFST);
> > +	writel(0UL, slim_rproc->peri + SLIM_CMD_MASK_OFST);
> > +
> > +	/* disable cpu pipeline clock */
> > +	writel(SLIM_CLK_GATE_DIS
> > +		, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
> 
> Odd placement of ','

Will fix.

> 
> > +
> > +	writel(!SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
> > +
> > +	val = readl(slim_rproc->slimcore + SLIM_EN_OFST);
> > +	if (val & SLIM_EN_RUN)
> > +		dev_warn(&rproc->dev, "Failed to disable SLIM");
> > +
> > +	slim_clk_disable(slim_rproc);
> > +
> > +	dev_dbg(&rproc->dev, "slim stopped\n");
> > +
> > +	return 0;
> > +}
> > +
> > +static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
> > +{
> > +	struct st_slim_rproc *slim_rproc = rproc->priv;
> > +	void *va = NULL;
> > +	int i;
> > +
> > +	for (i = 0; i < SLIM_MEM_MAX; i++) {
> > +		if (da != slim_rproc->mem[i].bus_addr)
> > +			continue;
> 
> Are you sure you want to enforce this being called with da == base? (I'm
> not totally against it).

Yes.

> 
> But you should probably double check that len is <= mem[i].size.

Good point, I will add a check for this.

> 
> > +		/* __force to make sparse happy with type conversion */
> > +		va = (__force void *)slim_rproc->mem[i].cpu_addr;
> > +		break;
> > +	}
> > +
> > +	dev_dbg(&rproc->dev, "%s: da = 0x%llx len = 0x%x va = 0x%p\n",
> > +		__func__, da, len, va);
> > +
> > +	return va;
> > +}
> > +
> > +static struct rproc_ops slim_rproc_ops = {
> > +	.start		= slim_rproc_start,
> > +	.stop		= slim_rproc_stop,
> > +	.da_to_va       = slim_rproc_da_to_va,
> > +};
> > +
> > +/**
> > + * Firmware handler operations: sanity, boot address, load ...
> > + */
> > +
> > +static struct resource_table empty_rsc_tbl = {
> > +	.ver = 1,
> > +	.num = 0,
> > +};
> > +
> > +static struct resource_table *slim_rproc_find_rsc_table(struct rproc *rproc,
> > +					       const struct firmware *fw,
> > +					       int *tablesz)
> > +{
> > +	if (!fw)
> > +		return NULL;
> 
> I consider it a BUG in the core to get here with fw == NULL, so please
> drop this.

Ok will drop in next version.

> 
> > +
> > +	*tablesz = sizeof(empty_rsc_tbl);
> > +	return &empty_rsc_tbl;
> > +}
> > +
> > +static struct resource_table *slim_rproc_find_loaded_rsc_table(struct rproc *rproc,
> > +						      const struct firmware *fw)
> > +{
> > +	if (!fw)
> > +		return NULL;
> > +
> 
> fw can't be NULL, so please drop this check.

Ok will fix.
> 
> > +	return &empty_rsc_tbl;
> 
> This function is supposed to return a pointer to the resource table as
> it appears in the space of the running firmware, so that any vring
> updates etc are visible to the remote.
> 
> As your firmware doesn't do this you should return NULL here, rather
> than a pointer back to the fake resource table.
> 
> But rproc_find_loaded_rsc_table() will do the same if you omit the
> reference in the fw_ops struct, so just make that NULL instead.

Good point. Will omit the reference in fw_ops struct in the next version.

> 
> > +}
> > +
> > +static struct rproc_fw_ops slim_rproc_fw_ops = {
> > +	.find_rsc_table = slim_rproc_find_rsc_table,
> > +	.find_loaded_rsc_table = slim_rproc_find_loaded_rsc_table,
> > +};
> > +
> > +
> > +/**
> > + * slim_rproc_alloc() - allocate and initialise slim rproc
> > + * @pdev: Pointer to the platform_device struct
> > + * @fw_name: Name of firmware for rproc to use
> > + *
> > + * Function for allocating and initialising a slim rproc for use by
> > + * device drivers whose IP is based around the slim slim core. It
> > + * obtains and enables any clocks required by the slim core and also
> > + * ioremaps the various IO.
> > + *
> > + * Returns st_slim_rproc pointer or PTR_ERR() on error.
> > + */
> > +
> > +struct st_slim_rproc *slim_rproc_alloc(struct platform_device *pdev,
> > +				char *fw_name)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct st_slim_rproc *slim_rproc;
> > +	struct device_node *np = dev->of_node;
> > +	struct rproc *rproc;
> > +	struct resource *res;
> > +	int err, i;
> > +	const struct rproc_fw_ops *elf_ops;
> > +
> > +	if (WARN_ON(!np || !fw_name))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	if (!of_device_is_compatible(np, "st,slim-rproc"))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	rproc = rproc_alloc(dev, np->name, &slim_rproc_ops,
> > +			fw_name, sizeof(*slim_rproc));
> > +	if (!rproc)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	rproc->has_iommu = false;
> > +
> > +	slim_rproc = rproc->priv;
> > +	slim_rproc->rproc = rproc;
> > +
> > +	elf_ops = rproc->fw_ops;
> > +	/* Use some generic elf ops */
> > +	slim_rproc_fw_ops.load = elf_ops->load;
> > +	slim_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
> > +
> > +	rproc->fw_ops = &slim_rproc_fw_ops;
> > +
> > +	/* get imem and dmem */
> > +	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
> > +
> > +		res = platform_get_resource_byname
> > +			(pdev, IORESOURCE_MEM, mem_names[i]);
> 
> This is an odd line breakage.

Will fix.
 
> 
> > +
> > +		slim_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
> > +		if (IS_ERR(slim_rproc->mem[i].cpu_addr)) {
> > +			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
> > +			err = PTR_ERR(slim_rproc->mem[i].cpu_addr);
> > +			goto err;
> > +		}
> > +		slim_rproc->mem[i].bus_addr = res->start;
> > +		slim_rproc->mem[i].size = resource_size(res);
> > +	}
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
> > +
> > +	slim_rproc->slimcore = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(slim_rproc->slimcore)) {
> > +		dev_err(&pdev->dev,
> > +			"devm_ioremap_resource failed for slimcore\n");
> > +		err = PTR_ERR(slim_rproc->slimcore);
> > +		goto err;
> > +	}
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
> > +
> > +	slim_rproc->peri = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(slim_rproc->peri)) {
> > +		dev_err(&pdev->dev, "devm_ioremap_resource failed for peri\n");
> > +		err = PTR_ERR(slim_rproc->peri);
> > +		goto err;
> > +	}
> > +
> > +	err = slim_clk_get(slim_rproc, dev);
> > +	if (err)
> > +		goto err;
> > +
> > +	/* Register as a remoteproc device */
> > +	err = rproc_add(rproc);
> > +	if (err) {
> > +		dev_err(dev, "registration of slim remoteproc failed\n");
> > +		goto err_clk;
> > +	}
> > +
> > +	return slim_rproc;
> > +
> > +err_clk:
> > +	for (i = 0; i < SLIM_MAX_CLK && slim_rproc->clks[i]; i++)
> > +		clk_put(slim_rproc->clks[i]);
> 
> Is there any chance to could acquire these clocks by name instead of
> just picking up 4 "random" clocks from the DT node?

Not using clock names here was deliberate because the slim core is used as a
basis for various IP's in the SoC, the clock names and number of them in the
functional spec for the particular IP can change a lot.

For instance all fdma instances have 4 clocks of various names, but the
c8sectpfe demux IP also based around slim core only has one clock called STFE.

The inspiration for this approach was taken from ehci-platform.c and
ohci-platform.c drivers which have to work across a wide range of SoC's from different
vendors and can also have many different clocks and clock names / reset lines
and reset names & phys etc.

> 
> You are generally supposed to use clock-names and could then use
> devm_clk_get() instead...
> 
> > +err:
> > +	rproc_put(rproc);
> > +	return ERR_PTR(err);
> > +}
> > +EXPORT_SYMBOL(slim_rproc_alloc);
> > +
> > +/**
> > +  * slim_rproc_put() - put slim rproc resources
> > +  * @slim_rproc: Pointer to the st_slim_rproc struct
> > +  *
> > +  * Function for calling respective _put() functions on
> > +  * slim_rproc resources.
> > +  *
> > +  */
> > +void slim_rproc_put(struct st_slim_rproc *slim_rproc)
> > +{
> > +	int clk;
> > +
> > +	if (!slim_rproc)
> > +		return;
> > +
> > +	for (clk = 0; clk < SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
> > +		clk_put(slim_rproc->clks[clk]);
> > +
> 
> You need to rproc_del() here before calling rproc_put().

Will fix.

> 
> > +	rproc_put(slim_rproc->rproc);
> > +}
> > +EXPORT_SYMBOL(slim_rproc_put);
> > +
> > +MODULE_AUTHOR("Peter Griffin");
> > +MODULE_DESCRIPTION("STMicroelectronics SLIM rproc driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/include/linux/remoteproc/st_slim_rproc.h b/include/linux/remoteproc/st_slim_rproc.h
> > new file mode 100644
> > index 0000000..c300b3e
> > --- /dev/null
> > +++ b/include/linux/remoteproc/st_slim_rproc.h
> > @@ -0,0 +1,53 @@
> > +/*
> > + * st_slim_rproc.h
> > + *
> > + * Copyright (C) 2016 STMicroelectronics
> > + * Author: Peter Griffin <[e-mail]>
> > + * License terms:  GNU General Public License (GPL), version 2
> > + */
> > +#ifndef _ST_SLIM_H
> > +#define _ST_SLIM_H
> > +
> > +#define SLIM_MEM_MAX 2
> > +#define SLIM_MAX_CLK 4
> > +
> > +enum {
> > +	SLIM_DMEM,
> > +	SLIM_IMEM,
> > +};
> > +
> > +/**
> > + * struct slim_mem - slim internal memory structure
> > + * @cpu_addr: MPU virtual address of the memory region
> > + * @bus_addr: Bus address used to access the memory region
> > + * @size: Size of the memory region
> > + */
> > +struct slim_mem {
> > +	void __iomem *cpu_addr;
> > +	phys_addr_t bus_addr;
> > +	size_t size;
> > +};
> > +
> 
> With things like slimbus being worked on I don't think it's appropriate
> to introduce public constants named SLIM_* or slim_*. Please rename
> these ST_SLIM_* and st_slim_*

Ok, will fix.

Regards,

Peter.

Patch

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 72e97d7..e9f12d0 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -86,4 +86,11 @@  config ST_REMOTEPROC
 	  processor framework.
 	  This can be either built-in or a loadable module.
 
+config ST_SLIM_REMOTEPROC
+	tristate "ST Slim remoteproc support"
+	help
+	  Say y here to support firmware loading on IP based around
+	  the Slim core.
+	  If unsure say N.
+
 endmenu
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 279cb2e..37bb39a 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -12,3 +12,4 @@  obj-$(CONFIG_STE_MODEM_RPROC)	 	+= ste_modem_rproc.o
 obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
 obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
+obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
diff --git a/drivers/remoteproc/st_slim_rproc.c b/drivers/remoteproc/st_slim_rproc.c
new file mode 100644
index 0000000..3b10d0c
--- /dev/null
+++ b/drivers/remoteproc/st_slim_rproc.c
@@ -0,0 +1,376 @@ 
+/*
+ * st_slim_rproc.c
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ * Author: Peter Griffin <[e-mail]>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc.h>
+#include <linux/remoteproc/st_slim_rproc.h>
+#include "remoteproc_internal.h"
+
+/* slimcore registers */
+#define SLIM_ID_OFST		0x0
+#define SLIM_VER_OFST		0x4
+
+#define SLIM_EN_OFST		0x8
+#define SLIM_EN_RUN			BIT(0)
+
+#define SLIM_CLK_GATE_OFST	0xC
+#define SLIM_CLK_GATE_DIS		BIT(0)
+#define SLIM_CLK_GATE_RESET		BIT(2)
+
+#define SLIM_SLIM_PC_OFST	0x20
+
+/* dmem registers */
+#define SLIM_REV_ID_OFST	0x0
+#define SLIM_REV_ID_MIN_MASK		GENMASK(15, 8)
+#define SLIM_REV_ID_MIN(id)		((id & SLIM_REV_ID_MIN_MASK) >> 8)
+#define SLIM_REV_ID_MAJ_MASK		GENMASK(23, 16)
+#define SLIM_REV_ID_MAJ(id)		((id & SLIM_REV_ID_MAJ_MASK) >> 16)
+
+
+/* peripherals registers */
+#define SLIM_STBUS_SYNC_OFST	0xF88
+#define SLIM_STBUS_SYNC_DIS		BIT(0)
+
+#define SLIM_INT_SET_OFST	0xFD4
+#define SLIM_INT_CLR_OFST	0xFD8
+#define SLIM_INT_MASK_OFST	0xFDC
+
+#define SLIM_CMD_CLR_OFST	0xFC8
+#define SLIM_CMD_MASK_OFST	0xFCC
+
+static const char *mem_names[SLIM_MEM_MAX] = {
+	[SLIM_DMEM]	= "dmem",
+	[SLIM_IMEM]	= "imem",
+};
+
+static int slim_clk_get(struct st_slim_rproc *slim_rproc, struct device *dev)
+{
+	int clk, err;
+
+	for (clk = 0; clk < SLIM_MAX_CLK; clk++) {
+		slim_rproc->clks[clk] = of_clk_get(dev->of_node, clk);
+		if (IS_ERR(slim_rproc->clks[clk])) {
+			err = PTR_ERR(slim_rproc->clks[clk]);
+			if (err == -EPROBE_DEFER)
+				goto err_put_clks;
+			slim_rproc->clks[clk] = NULL;
+			break;
+		}
+	}
+
+	return 0;
+
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(slim_rproc->clks[clk]);
+
+	return err;
+}
+
+static void slim_clk_disable(struct st_slim_rproc *slim_rproc)
+{
+	int clk;
+
+	for (clk = 0; clk < SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
+		clk_disable_unprepare(slim_rproc->clks[clk]);
+}
+
+static int slim_clk_enable(struct st_slim_rproc *slim_rproc)
+{
+	int clk, ret;
+
+	for (clk = 0; clk < SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++) {
+		ret = clk_prepare_enable(slim_rproc->clks[clk]);
+		if (ret)
+			goto err_disable_clks;
+	}
+
+	return 0;
+
+err_disable_clks:
+	while (--clk >= 0)
+		clk_disable_unprepare(slim_rproc->clks[clk]);
+
+	return ret;
+}
+
+/**
+ * Remoteproc slim specific device handlers
+ */
+static int slim_rproc_start(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	unsigned long hw_id, hw_ver, fw_rev;
+	u32 val;
+	int ret;
+
+	ret = slim_clk_enable(slim_rproc);
+	if (ret) {
+		dev_err(dev, "Failed to enable clocks\n");
+		goto err_clk;
+	}
+
+	/* disable CPU pipeline clock & reset cpu pipeline */
+	val = SLIM_CLK_GATE_DIS | SLIM_CLK_GATE_RESET;
+	writel(val, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	/* disable SLIM core STBus sync */
+	writel(SLIM_STBUS_SYNC_DIS, slim_rproc->peri + SLIM_STBUS_SYNC_OFST);
+
+	/* enable cpu pipeline clock */
+	writel(!SLIM_CLK_GATE_DIS,
+		slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	/* clear int & cmd mailbox */
+	writel(~0U, slim_rproc->peri + SLIM_INT_CLR_OFST);
+	writel(~0U, slim_rproc->peri + SLIM_CMD_CLR_OFST);
+
+	/* enable all channels cmd & int */
+	writel(~0U, slim_rproc->peri + SLIM_INT_MASK_OFST);
+	writel(~0U, slim_rproc->peri + SLIM_CMD_MASK_OFST);
+
+	/* enable cpu */
+	writel(SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
+
+	hw_id = readl_relaxed(slim_rproc->slimcore + SLIM_ID_OFST);
+	hw_ver = readl_relaxed(slim_rproc->slimcore + SLIM_VER_OFST);
+
+	fw_rev = readl(slim_rproc->mem[SLIM_DMEM].cpu_addr +
+			SLIM_REV_ID_OFST);
+
+	dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
+		 SLIM_REV_ID_MAJ(fw_rev), SLIM_REV_ID_MIN(fw_rev),
+		 hw_id, hw_ver);
+
+err_clk:
+	return ret;
+}
+
+static int slim_rproc_stop(struct rproc *rproc)
+{
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	u32 val;
+
+	/* mask all (cmd & int) channels */
+	writel(0UL, slim_rproc->peri + SLIM_INT_MASK_OFST);
+	writel(0UL, slim_rproc->peri + SLIM_CMD_MASK_OFST);
+
+	/* disable cpu pipeline clock */
+	writel(SLIM_CLK_GATE_DIS
+		, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	writel(!SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
+
+	val = readl(slim_rproc->slimcore + SLIM_EN_OFST);
+	if (val & SLIM_EN_RUN)
+		dev_warn(&rproc->dev, "Failed to disable SLIM");
+
+	slim_clk_disable(slim_rproc);
+
+	dev_dbg(&rproc->dev, "slim stopped\n");
+
+	return 0;
+}
+
+static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	void *va = NULL;
+	int i;
+
+	for (i = 0; i < SLIM_MEM_MAX; i++) {
+		if (da != slim_rproc->mem[i].bus_addr)
+			continue;
+		/* __force to make sparse happy with type conversion */
+		va = (__force void *)slim_rproc->mem[i].cpu_addr;
+		break;
+	}
+
+	dev_dbg(&rproc->dev, "%s: da = 0x%llx len = 0x%x va = 0x%p\n",
+		__func__, da, len, va);
+
+	return va;
+}
+
+static struct rproc_ops slim_rproc_ops = {
+	.start		= slim_rproc_start,
+	.stop		= slim_rproc_stop,
+	.da_to_va       = slim_rproc_da_to_va,
+};
+
+/**
+ * Firmware handler operations: sanity, boot address, load ...
+ */
+
+static struct resource_table empty_rsc_tbl = {
+	.ver = 1,
+	.num = 0,
+};
+
+static struct resource_table *slim_rproc_find_rsc_table(struct rproc *rproc,
+					       const struct firmware *fw,
+					       int *tablesz)
+{
+	if (!fw)
+		return NULL;
+
+	*tablesz = sizeof(empty_rsc_tbl);
+	return &empty_rsc_tbl;
+}
+
+static struct resource_table *slim_rproc_find_loaded_rsc_table(struct rproc *rproc,
+						      const struct firmware *fw)
+{
+	if (!fw)
+		return NULL;
+
+	return &empty_rsc_tbl;
+}
+
+static struct rproc_fw_ops slim_rproc_fw_ops = {
+	.find_rsc_table = slim_rproc_find_rsc_table,
+	.find_loaded_rsc_table = slim_rproc_find_loaded_rsc_table,
+};
+
+
+/**
+ * slim_rproc_alloc() - allocate and initialise slim rproc
+ * @pdev: Pointer to the platform_device struct
+ * @fw_name: Name of firmware for rproc to use
+ *
+ * Function for allocating and initialising a slim rproc for use by
+ * device drivers whose IP is based around the slim slim core. It
+ * obtains and enables any clocks required by the slim core and also
+ * ioremaps the various IO.
+ *
+ * Returns st_slim_rproc pointer or PTR_ERR() on error.
+ */
+
+struct st_slim_rproc *slim_rproc_alloc(struct platform_device *pdev,
+				char *fw_name)
+{
+	struct device *dev = &pdev->dev;
+	struct st_slim_rproc *slim_rproc;
+	struct device_node *np = dev->of_node;
+	struct rproc *rproc;
+	struct resource *res;
+	int err, i;
+	const struct rproc_fw_ops *elf_ops;
+
+	if (WARN_ON(!np || !fw_name))
+		return ERR_PTR(-EINVAL);
+
+	if (!of_device_is_compatible(np, "st,slim-rproc"))
+		return ERR_PTR(-EINVAL);
+
+	rproc = rproc_alloc(dev, np->name, &slim_rproc_ops,
+			fw_name, sizeof(*slim_rproc));
+	if (!rproc)
+		return ERR_PTR(-ENOMEM);
+
+	rproc->has_iommu = false;
+
+	slim_rproc = rproc->priv;
+	slim_rproc->rproc = rproc;
+
+	elf_ops = rproc->fw_ops;
+	/* Use some generic elf ops */
+	slim_rproc_fw_ops.load = elf_ops->load;
+	slim_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
+
+	rproc->fw_ops = &slim_rproc_fw_ops;
+
+	/* get imem and dmem */
+	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
+
+		res = platform_get_resource_byname
+			(pdev, IORESOURCE_MEM, mem_names[i]);
+
+		slim_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
+		if (IS_ERR(slim_rproc->mem[i].cpu_addr)) {
+			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
+			err = PTR_ERR(slim_rproc->mem[i].cpu_addr);
+			goto err;
+		}
+		slim_rproc->mem[i].bus_addr = res->start;
+		slim_rproc->mem[i].size = resource_size(res);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
+
+	slim_rproc->slimcore = devm_ioremap_resource(dev, res);
+	if (IS_ERR(slim_rproc->slimcore)) {
+		dev_err(&pdev->dev,
+			"devm_ioremap_resource failed for slimcore\n");
+		err = PTR_ERR(slim_rproc->slimcore);
+		goto err;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
+
+	slim_rproc->peri = devm_ioremap_resource(dev, res);
+	if (IS_ERR(slim_rproc->peri)) {
+		dev_err(&pdev->dev, "devm_ioremap_resource failed for peri\n");
+		err = PTR_ERR(slim_rproc->peri);
+		goto err;
+	}
+
+	err = slim_clk_get(slim_rproc, dev);
+	if (err)
+		goto err;
+
+	/* Register as a remoteproc device */
+	err = rproc_add(rproc);
+	if (err) {
+		dev_err(dev, "registration of slim remoteproc failed\n");
+		goto err_clk;
+	}
+
+	return slim_rproc;
+
+err_clk:
+	for (i = 0; i < SLIM_MAX_CLK && slim_rproc->clks[i]; i++)
+		clk_put(slim_rproc->clks[i]);
+err:
+	rproc_put(rproc);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(slim_rproc_alloc);
+
+/**
+  * slim_rproc_put() - put slim rproc resources
+  * @slim_rproc: Pointer to the st_slim_rproc struct
+  *
+  * Function for calling respective _put() functions on
+  * slim_rproc resources.
+  *
+  */
+void slim_rproc_put(struct st_slim_rproc *slim_rproc)
+{
+	int clk;
+
+	if (!slim_rproc)
+		return;
+
+	for (clk = 0; clk < SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
+		clk_put(slim_rproc->clks[clk]);
+
+	rproc_put(slim_rproc->rproc);
+}
+EXPORT_SYMBOL(slim_rproc_put);
+
+MODULE_AUTHOR("Peter Griffin");
+MODULE_DESCRIPTION("STMicroelectronics SLIM rproc driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/remoteproc/st_slim_rproc.h b/include/linux/remoteproc/st_slim_rproc.h
new file mode 100644
index 0000000..c300b3e
--- /dev/null
+++ b/include/linux/remoteproc/st_slim_rproc.h
@@ -0,0 +1,53 @@ 
+/*
+ * st_slim_rproc.h
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ * Author: Peter Griffin <[e-mail]>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#ifndef _ST_SLIM_H
+#define _ST_SLIM_H
+
+#define SLIM_MEM_MAX 2
+#define SLIM_MAX_CLK 4
+
+enum {
+	SLIM_DMEM,
+	SLIM_IMEM,
+};
+
+/**
+ * struct slim_mem - slim internal memory structure
+ * @cpu_addr: MPU virtual address of the memory region
+ * @bus_addr: Bus address used to access the memory region
+ * @size: Size of the memory region
+ */
+struct slim_mem {
+	void __iomem *cpu_addr;
+	phys_addr_t bus_addr;
+	size_t size;
+};
+
+/**
+ * struct st_slim_rproc - SLIM slim core
+ * @rproc: rproc handle
+ * @mem: slim memory information
+ * @slimcore: slim slimcore regs
+ * @peri: slim peripheral regs
+ * @clks: slim clocks
+ */
+struct st_slim_rproc {
+	struct rproc *rproc;
+	struct slim_mem mem[SLIM_MEM_MAX];
+	void __iomem *slimcore;
+	void __iomem *peri;
+
+	/* st_slim_rproc private */
+	struct clk *clks[SLIM_MAX_CLK];
+};
+
+struct st_slim_rproc *slim_rproc_alloc(struct platform_device *pdev,
+					char *fw_name);
+void slim_rproc_put(struct st_slim_rproc *slim_rproc);
+
+#endif