[v2,10/14] remoteproc/pru: Add PRU remoteproc driver

Commit Message

Roger Quadros Feb. 4, 2019, 2:22 p.m. UTC

From: Suman Anna <[e-mail]>

The Programmable Real-Time Unit Subsystem (PRUSS) consists of
dual 32-bit RISC cores (Programmable Real-Time Units, or PRUs)
for program execution. This patch adds a remoteproc platform
driver for managing the individual PRU RISC cores life cycle.

This remoteproc driver does not have support for error recovery
and system suspend/resume features. Different compatibles are
used to allow providing scalability for instance-specific device
data if needed. The driver uses a default firmware-name retrieved
from device-tree, and the firmwares are expected to be present
in the standard Linux firmware search paths. They can also be
adjusted by userspace if required through the sysfs interface
provided by the remoteproc core.

The PRU remoteproc driver uses a client-driven boot methodology
- it does _not_ support auto-boot so that the PRU load and boot
is dictated by the corresponding client drivers for achieving
various usecases. This allows flexibility for the client drivers
or applications to set a firmware name (if needed) based on their
desired functionality and boot the PRU. The sysfs bind and unbind
attributes have also been suppressed so that the PRU devices cannot
be unbound and thereby shutdown a PRU from underneath a PRU client
driver.

A new entry 'single_step' is added to the remoteproc debugfs dir.
The 'single_step' utilizes the single-step execution of the PRU
cores. Writing a non-zero value performs a single step, and a
zero value restores the PRU to execute in the same mode as the
mode before the first single step. (note: if the PRU is halted
because of a halt instruction, then no change occurs).

pru_rproc_get() and pru_rproc_put() functions allow client drivers
to acquire and release the remoteproc device associated with a PRU core.
The PRU cores are treated as resources with only one client owning
it at a time.

PRU interrupt mapping can be provided via devicetree using
ti,pru-interrupt-map property or via the resource table in the
firmware blob. If both are provided, the config in DT takes precedence.
For interrupt map via resource table, pru-software-support-package [1]
has been historically using version 0 for this. However, the current
data structure is not scaleable and is not self sufficient.
1) it hard codes number of channel to host mappings so is not
scaleable to newer SoCs than have more of these.
2) it does not contain the event to channel mappings within
itself but relies on a pointer to point to another section
in data memory. This causes a weird complication that the
respective data section must be loaded before we can really
use the INTC map.

With this patch we drop support for version 0 and support
version 1 which is a more robust and scalable data structure.
It should be able to support a sufficiently large number (255) of
sysevents, channels and host interrupts and is self contained
so it can be used without dependency on order of loading sections.

[1]  git://git.ti.com/pru-software-support-package/pru-software-support-package.git

Signed-off-by: Suman Anna <[e-mail]>
Signed-off-by: Andrew F. Davis <[e-mail]>
Signed-off-by: Tero Kristo <[e-mail]>
Signed-off-by: Roger Quadros <[e-mail]>
---
 drivers/remoteproc/Kconfig           |  14 +
 drivers/remoteproc/Makefile          |   1 +
 drivers/remoteproc/pru_rproc.c       | 930 +++++++++++++++++++++++++++++++++++
 drivers/remoteproc/pru_rproc.h       |  54 ++
 include/linux/remoteproc/pru_rproc.h |  27 +
 5 files changed, 1026 insertions(+)
 create mode 100644 drivers/remoteproc/pru_rproc.c
 create mode 100644 drivers/remoteproc/pru_rproc.h
 create mode 100644 include/linux/remoteproc/pru_rproc.h

Comments

Suman Anna Feb. 14, 2019, 2:35 a.m. UTC | #1

Hi Roger,

On 2/4/19 8:22 AM, Roger Quadros wrote:
> From: Suman Anna <[e-mail]>
> 
> The Programmable Real-Time Unit Subsystem (PRUSS) consists of
> dual 32-bit RISC cores (Programmable Real-Time Units, or PRUs)
> for program execution. This patch adds a remoteproc platform
> driver for managing the individual PRU RISC cores life cycle.
> 
> This remoteproc driver does not have support for error recovery
> and system suspend/resume features. Different compatibles are
> used to allow providing scalability for instance-specific device
> data if needed. The driver uses a default firmware-name retrieved
> from device-tree, and the firmwares are expected to be present
> in the standard Linux firmware search paths. They can also be
> adjusted by userspace if required through the sysfs interface
> provided by the remoteproc core.
> 
> The PRU remoteproc driver uses a client-driven boot methodology
> - it does _not_ support auto-boot so that the PRU load and boot
> is dictated by the corresponding client drivers for achieving
> various usecases. This allows flexibility for the client drivers
> or applications to set a firmware name (if needed) based on their
> desired functionality and boot the PRU. The sysfs bind and unbind
> attributes have also been suppressed so that the PRU devices cannot
> be unbound and thereby shutdown a PRU from underneath a PRU client
> driver.
> 
> A new entry 'single_step' is added to the remoteproc debugfs dir.
> The 'single_step' utilizes the single-step execution of the PRU
> cores. Writing a non-zero value performs a single step, and a
> zero value restores the PRU to execute in the same mode as the
> mode before the first single step. (note: if the PRU is halted
> because of a halt instruction, then no change occurs).
> 
> pru_rproc_get() and pru_rproc_put() functions allow client drivers
> to acquire and release the remoteproc device associated with a PRU core.
> The PRU cores are treated as resources with only one client owning
> it at a time.
> 
> PRU interrupt mapping can be provided via devicetree using
> ti,pru-interrupt-map property or via the resource table in the
> firmware blob. If both are provided, the config in DT takes precedence.
> For interrupt map via resource table, pru-software-support-package [1]
> has been historically using version 0 for this. However, the current
> data structure is not scaleable and is not self sufficient.
> 1) it hard codes number of channel to host mappings so is not
> scaleable to newer SoCs than have more of these.
> 2) it does not contain the event to channel mappings within
> itself but relies on a pointer to point to another section
> in data memory. This causes a weird complication that the
> respective data section must be loaded before we can really
> use the INTC map.
> 
> With this patch we drop support for version 0 and support
> version 1 which is a more robust and scalable data structure.
> It should be able to support a sufficiently large number (255) of
> sysevents, channels and host interrupts and is self contained
> so it can be used without dependency on order of loading sections.

Hmm, looks like you squashed a whole bunch of patches into this. I would
prefer some of the logical ones to be separated out just like before,
makes it easier to review the interfaces.

Looks like you have also changed usage behavior on couple of things and
dropped some of my original changes. I was not able to test this series
either on AM335x or on AM57xx to comment more on the behavior (not even
seeing the pruss devices populated, not sure what pieces are missing still).

> 
> [1]  git://git.ti.com/pru-software-support-package/pru-software-support-package.git
> 
> Signed-off-by: Suman Anna <[e-mail]>
> Signed-off-by: Andrew F. Davis <[e-mail]>
> Signed-off-by: Tero Kristo <[e-mail]>
> Signed-off-by: Roger Quadros <[e-mail]>
> ---
>  drivers/remoteproc/Kconfig           |  14 +
>  drivers/remoteproc/Makefile          |   1 +
>  drivers/remoteproc/pru_rproc.c       | 930 +++++++++++++++++++++++++++++++++++
>  drivers/remoteproc/pru_rproc.h       |  54 ++
>  include/linux/remoteproc/pru_rproc.h |  27 +
>  5 files changed, 1026 insertions(+)
>  create mode 100644 drivers/remoteproc/pru_rproc.c
>  create mode 100644 drivers/remoteproc/pru_rproc.h
>  create mode 100644 include/linux/remoteproc/pru_rproc.h
> 
> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> index f0abd26..333666e 100644
> --- a/drivers/remoteproc/Kconfig
> +++ b/drivers/remoteproc/Kconfig
> @@ -197,6 +197,20 @@ config ST_REMOTEPROC
>  config ST_SLIM_REMOTEPROC
>  	tristate
>  
> +config PRUSS_REMOTEPROC
> +	tristate "TI PRUSS remoteproc support"
> +	depends on TI_PRUSS
> +	default n
> +	help
> +	  Support for TI PRU-ICSS remote processors via the remote processor
> +	  framework.
> +
> +	  Currently supported on AM33xx SoCs.
> +
> +	  Say Y or M here to support the Programmable Realtime Unit (PRU)
> +	  processors on various TI SoCs. It's safe to say N here if you're
> +	  not interested in the PRU or if you are unsure.
> +
>  endif # REMOTEPROC
>  
>  endmenu
> diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> index ce5d061..88a86cc 100644
> --- a/drivers/remoteproc/Makefile
> +++ b/drivers/remoteproc/Makefile
> @@ -26,3 +26,4 @@ qcom_wcnss_pil-y			+= qcom_wcnss.o
>  qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
>  obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
>  obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
> +obj-$(CONFIG_PRUSS_REMOTEPROC)		+= pru_rproc.o
> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> new file mode 100644
> index 0000000..ddd4b64
> --- /dev/null
> +++ b/drivers/remoteproc/pru_rproc.c
> @@ -0,0 +1,930 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PRU-ICSS remoteproc driver for various TI SoCs
> + *
> + * Copyright (C) 2014-2019 Texas Instruments Incorporated - http://www.ti.com/
> + *	Suman Anna <[e-mail]>
> + *	Andrew F. Davis <[e-mail]>
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/debugfs.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip/irq-pruss-intc.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +#include <linux/remoteproc.h>
> +#include <linux/remoteproc/pru_rproc.h>
> +#include <linux/pruss.h>
> +
> +#include "remoteproc_internal.h"
> +#include "pru_rproc.h"
> +
> +/* ELF PAGE ID */
> +#define PRU_PAGE_IRAM	0
> +#define PRU_PAGE_DRAM	1
> +
> +/* IRAM offsets */
> +#define PRU0_IRAM_START		0x34000
> +#define PRU1_IRAM_START		0x38000
> +#define PRU_IRAM_MASK		0x3ffff
> +
> +/* PRU_ICSS_PRU_CTRL registers */
> +#define PRU_CTRL_CTRL		0x0000
> +#define PRU_CTRL_STS		0x0004
> +#define PRU_CTRL_WAKEUP_EN	0x0008
> +#define PRU_CTRL_CYCLE		0x000C
> +#define PRU_CTRL_STALL		0x0010
> +#define PRU_CTRL_CTBIR0		0x0020
> +#define PRU_CTRL_CTBIR1		0x0024
> +#define PRU_CTRL_CTPPR0		0x0028
> +#define PRU_CTRL_CTPPR1		0x002C
> +
> +/* CTRL register bit-fields */
> +#define CTRL_CTRL_SOFT_RST_N	BIT(0)
> +#define CTRL_CTRL_EN		BIT(1)
> +#define CTRL_CTRL_SLEEPING	BIT(2)
> +#define CTRL_CTRL_CTR_EN	BIT(3)
> +#define CTRL_CTRL_SINGLE_STEP	BIT(8)
> +#define CTRL_CTRL_RUNSTATE	BIT(15)
> +
> +/* PRU_ICSS_PRU_DEBUG registers */
> +#define PRU_DEBUG_GPREG(x)	(0x0000 + (x) * 4)
> +#define PRU_DEBUG_CT_REG(x)	(0x0080 + (x) * 4)
> +
> +/**
> + * struct pru_rproc - PRU remoteproc structure
> + * @id: id of the PRU core within the PRUSS
> + * @pruss: back-reference to parent PRUSS structure
> + * @rproc: remoteproc pointer for this PRU core
> + * @iram_region: PRU IRAM IOMEM
> + * @ctrl_regmap: regmap to PRU CTRL IOMEM
> + * @debug_regmap: regmap to PRU DEBUG IOMEM
> + * @client_np: client device node
> + * @intc_config: PRU INTC configuration data
> + * @dram0: PRUSS DRAM0 region
> + * @dram1: PRUSS DRAM1 region
> + * @shrdram: PRUSS SHARED RAM region
> + * @iram_da: device address of Instruction RAM for this PRU
> + * @pdram_da: device address of primary Data RAM for this PRU
> + * @sdram_da: device address of secondary Data RAM for this PRU
> + * @shrdram_da: device address of shared Data RAM
> + * @cfg: regmap to CFG module
> + * @gpcfg_reg: offset to gpcfg register of this PRU
> + * @fw_name: name of firmware image used during loading
> + * @gpmux_save: saved value for gpmux config
> + * @dt_irqs: number of irqs configured from DT
> + * @fw_irqs: number of irqs configured from FW
> + * @lock: mutex to protect client usage
> + * @dbg_single_step: debug state variable to set PRU into single step mode
> + * @ctrl_saved_state: saved CTRL state to return to normal mode
> + */
> +struct pru_rproc {
> +	int id;
> +	struct pruss *pruss;
> +	struct rproc *rproc;
> +	struct pruss_mem_region iram_region;
> +	struct regmap *ctrl_regmap;
> +	struct regmap *debug_regmap;
> +	struct device_node *client_np;
> +	struct pruss_intc_config intc_config;
> +	struct pruss_mem_region dram0;
> +	struct pruss_mem_region dram1;
> +	struct pruss_mem_region shrdram;
> +	u32 iram_da;
> +	u32 pdram_da;
> +	u32 sdram_da;
> +	u32 shrdram_da;
> +	struct regmap *cfg;
> +	int gpcfg_reg;
> +	const char *fw_name;
> +	u8 gpmux_save;
> +	int dt_irqs;
> +	int fw_irqs;
> +	struct mutex lock; /* client access lock */
> +	bool dbg_single_step;
> +	u32 ctrl_saved_state;
> +};
> +
> +/**
> + * pru_rproc_set_firmware() - set firmware for a pru core
> + * @rproc: the rproc instance of the PRU
> + * @fw_name: the new firmware name, or NULL if default is desired
> + */
> +static int pru_rproc_set_firmware(struct rproc *rproc, const char *fw_name)
> +{
> +	struct pru_rproc *pru = rproc->priv;
> +
> +	if (!fw_name)
> +		fw_name = pru->fw_name;
> +
> +	return rproc_set_firmware(rproc, fw_name);
> +}
> +
> +/*
> + * pru_get_gpmux() - get the current GPMUX value for a PRU device
> + * @pru: pru_rproc instance
> + * @mux: pointer to store the current mux value into
> + *
> + * returns 0 on success, negative error value otherwise.
> + */
> +static int pru_get_gpmux(struct pru_rproc *pru, u8 *mux)
> +{
> +	int ret;
> +	unsigned int val;
> +
> +	ret = regmap_read(pru->cfg, pru->gpcfg_reg, &val);
> +	if (ret)
> +		return ret;
> +
> +	*mux = (u8)((val & PRUSS_GPCFG_PRU_MUX_SEL_MASK) >>
> +		    PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
> +
> +	return 0;
> +}
> +
> +/**
> + * pru_set_gpmux() - set the GPMUX value for a PRU device
> + * @pru: pru_rproc instance
> + * @mux: new mux value for PRU
> + *
> + * returns 0 on success, negative error value otherwise.
> + */
> +static int pru_set_gpmux(struct pru_rproc *pru, u8 mux)
> +{
> +	if (mux >= PRUSS_GP_MUX_SEL_MAX)
> +		return -EINVAL;
> +
> +	return regmap_update_bits(pru->cfg, pru->gpcfg_reg,
> +				  PRUSS_GPCFG_PRU_MUX_SEL_MASK,
> +				  (u32)mux << PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
> +}
> +
> +static int pru_get_intc_dt_config(struct pru_rproc *pru,
> +				  const char *propname, int index,
> +				  struct pruss_intc_config *intc_config)
> +{
> +	struct device *dev = &pru->rproc->dev;
> +	struct device_node *np = pru->client_np;
> +	struct property *prop;
> +	int ret = 0, entries, i;
> +	int dt_irqs = 0;
> +	u32 *arr;
> +	int max_system_events, max_pru_channels, max_pru_host_ints;
> +
> +	max_system_events = MAX_PRU_SYS_EVENTS;
> +	max_pru_channels = MAX_PRU_CHANNELS;
> +	max_pru_host_ints = MAX_PRU_CHANNELS;
> +
> +	prop = of_find_property(np, propname, NULL);
> +	if (!prop)
> +		return 0;
> +
> +	entries = of_property_count_u32_elems(np, propname);
> +	if (entries <= 0 || entries % 4)
> +		return -EINVAL;
> +
> +	arr = kmalloc_array(entries, sizeof(u32), GFP_KERNEL);
> +	if (!arr)
> +		return -ENOMEM;
> +
> +	ret = of_property_read_u32_array(np, propname, arr, entries);
> +	if (ret)
> +		return -EINVAL;
> +
> +	for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++)
> +		intc_config->sysev_to_ch[i] = -1;
> +
> +	for (i = 0; i < ARRAY_SIZE(intc_config->ch_to_host); i++)
> +		intc_config->ch_to_host[i] = -1;
> +
> +	for (i = 0; i < entries; i += 4) {
> +		if (arr[i] != index)
> +			continue;
> +
> +		if (arr[i + 1] < 0 ||
> +		    arr[i + 1] >= max_system_events) {
> +			dev_err(dev, "bad sys event %d\n", arr[i + 1]);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (arr[i + 2] < 0 ||
> +		    arr[i + 2] >= max_pru_channels) {
> +			dev_err(dev, "bad channel %d\n", arr[i + 2]);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (arr[i + 3] < 0 ||
> +		    arr[i + 3] >= max_pru_host_ints) {
> +			dev_err(dev, "bad irq %d\n", arr[i + 3]);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		intc_config->sysev_to_ch[arr[i + 1]] = arr[i + 2];
> +		dev_dbg(dev, "sysevt-to-ch[%d] -> %d\n", arr[i + 1],
> +			arr[i + 2]);
> +
> +		intc_config->ch_to_host[arr[i + 2]] = arr[i + 3];
> +		dev_dbg(dev, "chnl-to-host[%d] -> %d\n", arr[i + 2],
> +			arr[i + 3]);
> +
> +		dt_irqs++;
> +	}
> +
> +	kfree(arr);
> +	return dt_irqs;
> +
> +err:
> +	kfree(arr);
> +	return ret;
> +}
> +
> +static struct rproc *__pru_rproc_get(struct device_node *np, int index)
> +{
> +	struct device_node *rproc_np = NULL;
> +	struct platform_device *pdev;
> +	struct rproc *rproc;
> +
> +	rproc_np = of_parse_phandle(np, "prus", index);
> +	if (!rproc_np || !of_device_is_available(rproc_np))
> +		return ERR_PTR(-ENODEV);
> +
> +	pdev = of_find_device_by_node(rproc_np);
> +	of_node_put(rproc_np);
> +
> +	if (!pdev)
> +		/* probably PRU not yet probed */
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	/* TODO: replace the crude string based check to make sure it is PRU */
> +	if (!strstr(dev_name(&pdev->dev), "pru")) {
> +		put_device(&pdev->dev);
> +		return ERR_PTR(-ENODEV);
> +	}
> +
> +	rproc = platform_get_drvdata(pdev);
> +	put_device(&pdev->dev);
> +	if (!rproc)
> +		return ERR_PTR(-EPROBE_DEFER);
> +
> +	get_device(&rproc->dev);
> +
> +	return rproc;
> +}
> +
> +/**
> + * pru_rproc_get() - get the PRU rproc instance from a device node
> + * @np: the user/client device node
> + * @index: index to use for the prus property
> + *
> + * This function looks through a client device node's "prus" property at index
> + * @index and returns the rproc handle for a valid PRU remote processor if
> + * found. The function allows only one user to own the PRU rproc resource at
> + * a time. Caller must call pru_rproc_put() when done with using the rproc,
> + * not required if the function returns a failure.
> + *
> + * Returns the rproc handle on success, and an ERR_PTR on failure using one
> + * of the following error values
> + *    -ENODEV if device is not found
> + *    -EBUSY if PRU is already acquired by anyone
> + *    -EPROBE_DEFER is PRU device is not probed yet
> + */
> +struct rproc *pru_rproc_get(struct device_node *np, int index)
> +{
> +	struct rproc *rproc;
> +	struct pru_rproc *pru;
> +	struct device *dev;
> +	int ret;
> +	u32 mux;
> +	const char *fw_name;
> +
> +	rproc = __pru_rproc_get(np, index);
> +	if (IS_ERR(rproc))
> +		return rproc;
> +
> +	pru = rproc->priv;
> +	dev = &rproc->dev;
> +
> +	mutex_lock(&pru->lock);
> +
> +	if (pru->client_np) {
> +		mutex_unlock(&pru->lock);
> +		put_device(&rproc->dev);
> +		return ERR_PTR(-EBUSY);
> +	}
> +
> +	pru->client_np = np;
> +
> +	mutex_unlock(&pru->lock);
> +
> +	ret = pru_get_gpmux(pru, &pru->gpmux_save);
> +	if (ret) {
> +		dev_err(dev, "failed to get cfg gpmux: %d\n", ret);
> +		goto err;
> +	}
> +
> +	ret = of_property_read_u32_index(np, "ti,pruss-gp-mux-sel", index,
> +					 &mux);
> +	if (!ret) {
> +		ret = pru_set_gpmux(pru, mux);
> +		if (ret) {
> +			dev_err(dev, "failed to set cfg gpmux: %d\n", ret);
> +			goto err;
> +		}
> +	}
> +
> +	ret = of_property_read_string_index(np, "firmware-name", index,
> +					    &fw_name);
> +	if (!ret) {
> +		ret = pru_rproc_set_firmware(rproc, fw_name);
> +		if (ret) {
> +			dev_err(dev, "failed to set firmware: %d\n", ret);
> +			goto err;
> +		}
> +	}
> +
> +	ret = pru_get_intc_dt_config(pru, "ti,pru-interrupt-map",
> +				     index, &pru->intc_config);
> +	if (ret < 0) {
> +		dev_err(dev, "error getting DT interrupt map: %d\n", ret);
> +		goto err;
> +	}
> +
> +	pru->dt_irqs = ret;
> +
> +	return rproc;
> +
> +err:
> +	pru_rproc_put(rproc);
> +	return ERR_PTR(ret);
> +}
> +EXPORT_SYMBOL_GPL(pru_rproc_get);
> +
> +/**
> + * pru_rproc_put() - release the PRU rproc resource
> + * @rproc: the rproc resource to release
> + *
> + * Releases the PRU rproc resource and makes it available to other
> + * users.
> + */
> +void pru_rproc_put(struct rproc *rproc)
> +{
> +	struct pru_rproc *pru;
> +
> +	if (IS_ERR_OR_NULL(rproc))
> +		return;
> +
> +	/* TODO: replace the crude string based check to make sure it is PRU */
> +	if (!strstr(dev_name(rproc->dev.parent), "pru"))
> +		return;
> +
> +	pru = rproc->priv;
> +	if (!pru->client_np)
> +		return;
> +
> +	pru_rproc_set_firmware(rproc, NULL);
> +	pru_set_gpmux(pru, pru->gpmux_save);
> +
> +	mutex_lock(&pru->lock);
> +	pru->client_np = NULL;
> +	mutex_unlock(&pru->lock);
> +
> +	put_device(&rproc->dev);
> +}
> +EXPORT_SYMBOL_GPL(pru_rproc_put);
> +
> +/*
> + * Control PRU single-step mode
> + *
> + * This is a debug helper function used for controlling the single-step
> + * mode of the PRU. The PRU Debug registers are not accessible when the
> + * PRU is in RUNNING state.
> + *
> + * Writing a non-zero value sets the PRU into single-step mode irrespective
> + * of its previous state. The PRU mode is saved only on the first set into
> + * a single-step mode. Writing a zero value will restore the PRU into its
> + * original mode.
> + */
> +static int pru_rproc_debug_ss_set(void *data, u64 val)
> +{
> +	struct rproc *rproc = data;
> +	struct pru_rproc *pru = rproc->priv;
> +	u32 reg_val;
> +	bool debug_ss;
> +
> +	debug_ss = !!val;
> +	if (!debug_ss && !pru->dbg_single_step)
> +		return 0;
> +
> +	regmap_read(pru->ctrl_regmap, PRU_CTRL_CTRL, &reg_val);
> +
> +	if (debug_ss && !pru->dbg_single_step)
> +		pru->ctrl_saved_state = reg_val;
> +
> +	if (debug_ss)
> +		reg_val |= CTRL_CTRL_SINGLE_STEP | CTRL_CTRL_EN;
> +	else
> +		reg_val = pru->ctrl_saved_state;
> +
> +	pru->dbg_single_step = debug_ss;
> +	regmap_write(pru->ctrl_regmap, PRU_CTRL_CTRL, reg_val);
> +
> +	return 0;
> +}
> +
> +static int pru_rproc_debug_ss_get(void *data, u64 *val)
> +{
> +	struct rproc *rproc = data;
> +	struct pru_rproc *pru = rproc->priv;
> +
> +	*val = pru->dbg_single_step;
> +
> +	return 0;
> +}
> +DEFINE_SIMPLE_ATTRIBUTE(pru_rproc_debug_ss_fops, pru_rproc_debug_ss_get,
> +			pru_rproc_debug_ss_set, "%llu\n");
> +
> +/*
> + * Create PRU-specific debugfs entries
> + *
> + * The entries are created only if the parent remoteproc debugfs directory
> + * exists, and will be cleaned up by the remoteproc core.
> + */
> +static void pru_rproc_create_debug_entries(struct rproc *rproc)
> +{
> +	if (!rproc->dbg_dir)
> +		return;
> +
> +	debugfs_create_file("single_step", 0600, rproc->dbg_dir,
> +			    rproc, &pru_rproc_debug_ss_fops);
> +}
> +
> +static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, int len);
> +
> +/*
> + * parse the custom interrupt map resource and save the intc_config
> + * for use when booting the processor.
> + */
> +static int pru_handle_vendor_intrmap(struct rproc *rproc,
> +				     struct fw_rsc_pruss_intrmap *rsc)
> +{
> +	int fw_irqs = 0, i, ret = 0;
> +	u8 *arr;
> +	struct device *dev = &rproc->dev;
> +	struct pru_rproc *pru = rproc->priv;
> +
> +	dev_dbg(dev, "vendor rsc intc: version %d\n", rsc->version);
> +
> +	/*
> +	 * 0 was prototyping version. Not supported.
> +	 * 1 is currently supported version.
> +	 */
> +	if (rsc->version == 0 || rsc->version > 1) {
> +		dev_err(dev, "Unsupported version %d\n", rsc->version);
> +		return -EINVAL;
> +	}
> +
> +	/* DT provided INTC config takes precedence */
> +	if (pru->dt_irqs) {
> +		dev_info(dev, "INTC config in DT and FW. Using DT config.\n");
> +		return 0;
> +	}
> +
> +	arr = rsc->data;
> +
> +	for (i = 0; i < ARRAY_SIZE(pru->intc_config.sysev_to_ch); i++)
> +		pru->intc_config.sysev_to_ch[i] = -1;
> +
> +	for (i = 0; i < ARRAY_SIZE(pru->intc_config.ch_to_host); i++)
> +		pru->intc_config.ch_to_host[i] = -1;
> +
> +	for (i = 0; i < rsc->num_maps * 3; i += 3) {
> +		if (arr[i] < 0 ||
> +		    arr[i] >= MAX_PRU_SYS_EVENTS) {
> +			dev_err(dev, "bad sys event %d\n", arr[i]);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (arr[i + 1] < 0 ||
> +		    arr[i + 1] >= MAX_PRU_CHANNELS) {
> +			dev_err(dev, "bad channel %d\n", arr[i + 1]);
> +			ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		if (arr[i + 2] < 0 ||
> +		    arr[i + 2] >= MAX_PRU_CHANNELS) {
> +			dev_err(dev, "bad host irq %d\n", arr[i + 2]);
> +				ret = -EINVAL;
> +			goto err;
> +		}
> +
> +		pru->intc_config.sysev_to_ch[arr[i]] = arr[i + 1];
> +		dev_dbg(dev, "sysevt-to-ch[%d] -> %d\n", arr[i],
> +			arr[i + 1]);
> +
> +		pru->intc_config.ch_to_host[arr[i + 1]] = arr[i + 2];
> +		dev_dbg(dev, "chnl-to-host[%d] -> %d\n", arr[i + 1],
> +			arr[i + 2]);
> +
> +		fw_irqs++;
> +	}
> +
> +	pru->fw_irqs = fw_irqs;
> +	return 0;
> +
> +err:
> +	pru->fw_irqs = 0;
> +	return ret;
> +}
> +
> +/* PRU-specific vendor resource handler */
> +static int pru_rproc_handle_vendor_rsc(struct rproc *rproc,
> +				       struct fw_rsc_vendor *ven_rsc)
> +{
> +	struct device *dev = rproc->dev.parent;
> +	int ret = -EINVAL;
> +
> +	struct fw_rsc_pruss_intrmap *rsc;
> +
> +	rsc = (struct fw_rsc_pruss_intrmap *)ven_rsc->data;
> +
> +	switch (rsc->type) {
> +	case PRUSS_RSC_INTRS:
> +		ret = pru_handle_vendor_intrmap(rproc, rsc);
> +		break;
> +	default:
> +		dev_err(dev, "%s: cannot handle unknown type %d\n", __func__,
> +			rsc->type);
> +	}
> +
> +	return ret;
> +}
> +
> +/* start a PRU core */
> +static int pru_rproc_start(struct rproc *rproc)
> +{
> +	struct device *dev = &rproc->dev;
> +	struct pru_rproc *pru = rproc->priv;
> +	u32 val;
> +	int ret;
> +
> +	dev_dbg(dev, "starting PRU%d: entry-point = 0x%x\n",
> +		pru->id, (rproc->bootaddr >> 2));
> +
> +	if (pru->dt_irqs || pru->fw_irqs) {
> +		ret = pruss_intc_configure(rproc->dev.parent,
> +					   &pru->intc_config);
> +		if (ret) {
> +			dev_err(dev, "failed to configure intc %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	val = CTRL_CTRL_EN | ((rproc->bootaddr >> 2) << 16);
> +	regmap_write(pru->ctrl_regmap, PRU_CTRL_CTRL, val);
> +
> +	return 0;
> +}
> +
> +/* stop/disable a PRU core */
> +static int pru_rproc_stop(struct rproc *rproc)
> +{
> +	struct device *dev = &rproc->dev;
> +	struct pru_rproc *pru = rproc->priv;
> +
> +	dev_dbg(dev, "stopping PRU%d\n", pru->id);
> +	regmap_update_bits(pru->ctrl_regmap, PRU_CTRL_CTRL, CTRL_CTRL_EN, 0);
> +
> +	/* undo INTC config */
> +	if (pru->dt_irqs || pru->fw_irqs)
> +		pruss_intc_unconfigure(rproc->dev.parent, &pru->intc_config);
> +
> +	return 0;
> +}
> +
> +/*
> + * Convert PRU device address (data spaces only) to kernel virtual address
> + *
> + * Each PRU has access to all data memories within the PRUSS, accessible at
> + * different ranges. So, look through both its primary and secondary Data
> + * RAMs as well as any shared Data RAM to convert a PRU device address to
> + * kernel virtual address. Data RAM0 is primary Data RAM for PRU0 and Data
> + * RAM1 is primary Data RAM for PRU1.
> + */
> +static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, int len)
> +{
> +	struct pruss_mem_region dram0, dram1, shrd_ram;
> +	u32 offset;
> +	void *va = NULL;
> +
> +	if (len <= 0)
> +		return NULL;
> +
> +	dram0 = pru->dram0;
> +	dram1 = pru->dram1;
> +	/* PRU1 has its local RAM addresses reversed */
> +	if (pru->id == 1)
> +		swap(dram0, dram1);
> +	shrd_ram = pru->shrdram;
> +
> +	if (da >= pru->pdram_da && da + len <= pru->pdram_da + dram0.size) {
> +		offset = da - pru->pdram_da;
> +		va = (__force void *)(dram0.va + offset);
> +	} else if (da >= pru->sdram_da &&
> +		   da + len <= pru->sdram_da + dram1.size) {
> +		offset = da - pru->sdram_da;
> +		va = (__force void *)(dram1.va + offset);
> +	} else if (da >= pru->shrdram_da &&
> +		   da + len <= pru->shrdram_da + shrd_ram.size) {
> +		offset = da - pru->shrdram_da;
> +		va = (__force void *)(shrd_ram.va + offset);
> +	}
> +
> +	return va;
> +}
> +
> +/*
> + * Convert PRU device address (instruction space) to kernel virtual address
> + *
> + * A PRU does not have an unified address space. Each PRU has its very own
> + * private Instruction RAM, and its device address is identical to that of
> + * its primary Data RAM device address.
> + */
> +static void *pru_i_da_to_va(struct pru_rproc *pru, u32 da, int len)
> +{
> +	u32 offset;
> +	void *va = NULL;
> +
> +	if (len <= 0)
> +		return NULL;
> +
> +	if (da >= pru->iram_da &&
> +	    da + len <= pru->iram_da + pru->iram_region.size) {
> +		offset = da - pru->iram_da;
> +		va = (__force void *)(pru->iram_region.va + offset);
> +	}
> +
> +	return va;
> +}
> +
> +/* PRU-specific address translator */
> +static void *pru_da_to_va(struct rproc *rproc, u64 da, int len, int map)
> +{
> +	struct pru_rproc *pru = rproc->priv;
> +	void *va;
> +
> +	switch (map) {
> +	case PRU_PAGE_IRAM:
> +		va = pru_i_da_to_va(pru, da, len);
> +		break;
> +	case PRU_PAGE_DRAM:
> +		va = pru_d_da_to_va(pru, da, len);
> +		break;
> +	default:
> +		dev_info(&rproc->dev, "%s: invalid page %d\n", __func__, map);
> +		return 0;
> +	};
> +
> +	return va;
> +}
> +
> +static struct rproc_ops pru_rproc_ops = {
> +	.start			= pru_rproc_start,
> +	.stop			= pru_rproc_stop,
> +	.da_to_va		= pru_da_to_va,
> +	.handle_vendor_rsc	= pru_rproc_handle_vendor_rsc,
> +};
> +
> +static int pru_rproc_set_id(struct pru_rproc *pru)
> +{
> +	int ret = 0;
> +	u32 iram_start = pru->iram_region.pa & PRU_IRAM_MASK;
> +
> +	if (iram_start == PRU0_IRAM_START)
> +		pru->id = 0;
> +	else if (iram_start == PRU1_IRAM_START)
> +		pru->id = 1;
> +	else
> +		ret = -EINVAL;
> +
> +	return ret;
> +}
> +
> +static struct regmap_config pru_ctrl_regmap_config = {
> +	.name = "ctrl",
> +	.reg_bits = 32,
> +	.reg_stride = 4,
> +	.val_bits = 32,
> +	.max_register = PRU_CTRL_CTPPR1,
> +};
> +
> +static struct regmap_config pru_debug_regmap_config = {
> +	.name = "debug",
> +	.reg_bits = 32,
> +	.reg_stride = 4,
> +	.val_bits = 32,
> +	.max_register = PRU_DEBUG_CT_REG(31),
> +};
> +
> +static int pru_rproc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	struct platform_device *ppdev = to_platform_device(dev->parent);
> +	struct pru_rproc *pru;
> +	const char *fw_name;
> +	struct rproc *rproc = NULL;
> +	struct resource *res;
> +	int ret;
> +	void __iomem *va;
> +
> +	if (!np) {
> +		dev_err(dev, "Non-DT platform device not supported\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = of_property_read_string(np, "firmware-name", &fw_name);
> +	if (ret) {
> +		dev_err(dev, "unable to retrieve firmware-name %d\n", ret);
> +		return ret;
> +	}
> +
> +	rproc = rproc_alloc(dev, pdev->name, &pru_rproc_ops, fw_name,
> +			    sizeof(*pru));
> +	if (!rproc) {
> +		dev_err(dev, "rproc_alloc failed\n");
> +		return -ENOMEM;
> +	}
> +
> +	pru = rproc->priv;
> +	pru->cfg = syscon_regmap_lookup_by_phandle(np, "gpcfg");
> +	if (IS_ERR(pru->cfg)) {
> +		if (PTR_ERR(pru->cfg) != -EPROBE_DEFER)
> +			dev_err(dev, "can't get gpcfg syscon regmap\n");
> +
> +		return PTR_ERR(pru->cfg);
> +	}
> +
> +	if (of_property_read_u32_index(np, "gpcfg", 1, &pru->gpcfg_reg)) {
> +		dev_err(dev, "couldn't get gpcfg reg. offset\n");
> +		return -EINVAL;
> +	}
> +
> +	/* error recovery is not supported for PRUs */
> +	rproc->recovery_disabled = true;
> +
> +	/*
> +	 * rproc_add will auto-boot the processor normally, but this is
> +	 * not desired with PRU client driven boot-flow methodology. A PRU
> +	 * application/client driver will boot the corresponding PRU
> +	 * remote-processor as part of its state machine either through
> +	 * the remoteproc sysfs interface or through the equivalent kernel API
> +	 */
> +	rproc->auto_boot = false;
> +
> +	pru->pruss = platform_get_drvdata(ppdev);
> +	pru->rproc = rproc;
> +	pru->fw_name = fw_name;
> +	mutex_init(&pru->lock);
> +
> +	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_DRAM0,
> +				       &pru->dram0);
> +	if (ret) {
> +		dev_err(dev, "couldn't get PRUSS DRAM0: %d\n", ret);
> +		return ret;
> +	}
> +	pruss_release_mem_region(pru->pruss, &pru->dram0);
> +
> +	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_DRAM1,
> +				       &pru->dram1);
> +	if (ret) {
> +		dev_err(dev, "couldn't get PRUSS DRAM1: %d\n", ret);
> +		return ret;
> +	}
> +	pruss_release_mem_region(pru->pruss, &pru->dram1);
> +
> +	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_SHRD_RAM2,
> +				       &pru->shrdram);
> +	if (ret) {
> +		dev_err(dev, "couldn't get PRUSS Shared RAM: %d\n", ret);
> +		return ret;
> +	}
> +	pruss_release_mem_region(pru->pruss, &pru->shrdram);

Are you doing this because now you don't have access to the pruss
structure?

> +
> +	/* XXX: get this from match data if different in the future */
> +	pru->iram_da = 0;
> +	pru->pdram_da = 0;
> +	pru->sdram_da = 0x2000;
> +	pru->shrdram_da = 0x10000;
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iram");
> +	pru->iram_region.va = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(pru->iram_region.va)) {
> +		ret = PTR_ERR(pru->iram_region.va);
> +		dev_err(dev, "failed to get iram resource: %d\n", ret);
> +		goto free_rproc;
> +	}
> +
> +	pru->iram_region.pa = res->start;
> +	pru->iram_region.size = resource_size(res);
> +
> +	dev_dbg(dev, "iram: pa %pa size 0x%zx va %p\n",
> +		&pru->iram_region.pa, pru->iram_region.size,
> +		pru->iram_region.va);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
> +	va = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(va)) {
> +		ret = PTR_ERR(va);
> +		dev_err(dev, "failed to get control resource: %d\n", ret);
> +		goto free_rproc;
> +	}
> +
> +	pru->ctrl_regmap = devm_regmap_init_mmio(dev, va,
> +						 &pru_ctrl_regmap_config);
> +	if (IS_ERR(pru->ctrl_regmap)) {
> +		ret = PTR_ERR(pru->ctrl_regmap);
> +		dev_err(dev, "CTRL regmap init failed: %d\n", ret);
> +		goto free_rproc;
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "debug");
> +	va = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(va)) {
> +		ret = PTR_ERR(va);
> +		dev_err(dev, "failed to get debug resource: %d\n", ret);
> +		goto free_rproc;
> +	}
> +	pru->debug_regmap = devm_regmap_init_mmio(dev, va,
> +						  &pru_debug_regmap_config);
> +	if (IS_ERR(pru->debug_regmap)) {
> +		ret = PTR_ERR(pru->debug_regmap);
> +		dev_err(dev, "DEBUG regmap init failed: %d\n", ret);
> +		goto free_rproc;
> +	}

I am not a big fan of this regmap conversion. Using it just for the sake
of leveraging regmap debugfs seems overkill, where does the debugfs
files show up for that? Also, I had logic around when the registers can
be accessed, so not sure if you have tested the behavior when the PRUs
are executing.

> +
> +	ret = pru_rproc_set_id(pru);
> +	if (ret < 0)
> +		goto free_rproc;
> +
> +	platform_set_drvdata(pdev, rproc);
> +
> +	ret = rproc_add(pru->rproc);
> +	if (ret) {
> +		dev_err(dev, "rproc_add failed: %d\n", ret);
> +		goto free_rproc;
> +	}
> +
> +	pru_rproc_create_debug_entries(rproc);
> +
> +	dev_info(dev, "PRU rproc node %s probed successfully\n", np->full_name);
> +
> +	return 0;
> +
> +free_rproc:
> +	rproc_free(rproc);
> +	return ret;
> +}
> +
> +static int pru_rproc_remove(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct rproc *rproc = platform_get_drvdata(pdev);
> +
> +	dev_info(dev, "%s: removing rproc %s\n", __func__, rproc->name);
> +
> +	rproc_del(rproc);
> +	rproc_free(rproc);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id pru_rproc_match[] = {
> +	{ .compatible = "ti,am3356-pru", },
> +	{ .compatible = "ti,am4376-pru", },
> +	{ .compatible = "ti,am5728-pru", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, pru_rproc_match);
> +
> +static struct platform_driver pru_rproc_driver = {
> +	.driver = {
> +		.name   = "pru-rproc",
> +		.of_match_table = pru_rproc_match,
> +		.suppress_bind_attrs = true,
> +	},
> +	.probe  = pru_rproc_probe,
> +	.remove = pru_rproc_remove,
> +};
> +module_platform_driver(pru_rproc_driver);
> +
> +MODULE_AUTHOR("Suman Anna <[e-mail]>");
> +MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/remoteproc/pru_rproc.h b/drivers/remoteproc/pru_rproc.h
> new file mode 100644
> index 0000000..bbcf392
> --- /dev/null
> +++ b/drivers/remoteproc/pru_rproc.h
> @@ -0,0 +1,54 @@
> +/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
> +/*
> + * PRUSS Remote Processor specific types
> + *
> + * Copyright (C) 2014-2019 Texas Instruments Incorporated - http://www.ti.com/
> + * All rights reserved.
> + */
> +
> +#ifndef _PRU_REMOTEPROC_H_
> +#define _PRU_REMOTEPROC_H_
> +
> +/**
> + * enum pruss_rsc_types - PRU specific resource types
> + *
> + * @PRUSS_RSC_INTRS: Resource holding information on PRU PINTC configuration
> + * @PRUSS_RSC_MAX: Indicates end of known/defined PRU resource types.
> + *		   This should be the last definition.
> + *
> + * Introduce new custom resource types before PRUSS_RSC_MAX.
> + */
> +enum pruss_rsc_types {
> +	PRUSS_RSC_INTRS	= 1,
> +	PRUSS_RSC_MAX	= 2,
> +};
> +
> +/**
> + * struct fw_rsc_pruss_intrmap - vendor resource to define PRU interrupts
> + * @type: should be PRUSS_RSC_INTRS
> + * @version: should be 1 or greater. 0 was for prototyping and is not supported
> + * @num_maps: number of interrupt mappings that follow
> + * @data: Array of 'num_maps' mappings.
> + *		Each mapping is a triplet {s, c, h}
> + *		s - system event id
> + *		c - channel id
> + *		h - host interrupt id
> + *
> + * PRU system events are mapped to channels, and these channels are mapped
> + * to host interrupts. Events can be mapped to channels in a one-to-one or
> + * many-to-one ratio (multiple events per channel), and channels can be
> + * mapped to host interrupts in a one-to-one or many-to-one ratio (multiple
> + * channels per interrupt).
> + *
> + * This resource is variable length due to the nature of INTC map.
> + * The below data structure is scalable so it can support sufficiently
> + * large number of sysevents and hosts.
> + */
> +struct fw_rsc_pruss_intrmap {
> +	u16 type;
> +	u16 version;
> +	u8 num_maps;
> +	u8 data[];

I can comment more on this once I get a testable version, but I explored
this idea initially before abandoning this. We would want to prefer
using as small an amount of memory as possible, as the resource table
has to be loaded into memory. The channel to host mapping need to be
defined only once for a channel, and not needed for every event.

Also, I am not sure if your current logic is handling the resource size
availability check with this open-ended structure definition.

regards
Suman

> +} __packed;
> +
> +#endif	/* _PRU_REMOTEPROC_H_ */
> diff --git a/include/linux/remoteproc/pru_rproc.h b/include/linux/remoteproc/pru_rproc.h
> new file mode 100644
> index 0000000..841da09
> --- /dev/null
> +++ b/include/linux/remoteproc/pru_rproc.h
> @@ -0,0 +1,27 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/**
> + * PRU-ICSS Remote Subsystem user interfaces
> + *
> + * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
> + */
> +
> +#ifndef __LINUX_REMOTEPROC_PRU_RPROC_H
> +#define __LINUX_REMOTEPROC_PRU_RPROC_H
> +
> +#if IS_ENABLED(CONFIG_PRUSS_REMOTEPROC)
> +
> +struct rproc *pru_rproc_get(struct device_node *node, int index);
> +void pru_rproc_put(struct rproc *rproc);
> +
> +#else
> +
> +static inline struct rproc *pru_rproc_get(struct device_node *node, int index)
> +{
> +	return ERR_PTR(-ENOTSUPP);
> +}
> +
> +static inline void pru_rproc_put(struct rproc *rproc) { }
> +
> +#endif /* CONFIG_PRUSS_REMOTEPROC */
> +
> +#endif /* __LINUX_REMOTEPROC_PRU_RPROC_H */
>

Suman Anna Feb. 14, 2019, 3:44 a.m. UTC | #2

On 2/13/19 8:35 PM, Suman Anna wrote:
> Hi Roger,
> 
> On 2/4/19 8:22 AM, Roger Quadros wrote:
>> From: Suman Anna <[e-mail]>
>>
>> The Programmable Real-Time Unit Subsystem (PRUSS) consists of
>> dual 32-bit RISC cores (Programmable Real-Time Units, or PRUs)
>> for program execution. This patch adds a remoteproc platform
>> driver for managing the individual PRU RISC cores life cycle.
>>
>> This remoteproc driver does not have support for error recovery
>> and system suspend/resume features. Different compatibles are
>> used to allow providing scalability for instance-specific device
>> data if needed. The driver uses a default firmware-name retrieved
>> from device-tree, and the firmwares are expected to be present
>> in the standard Linux firmware search paths. They can also be
>> adjusted by userspace if required through the sysfs interface
>> provided by the remoteproc core.
>>
>> The PRU remoteproc driver uses a client-driven boot methodology
>> - it does _not_ support auto-boot so that the PRU load and boot
>> is dictated by the corresponding client drivers for achieving
>> various usecases. This allows flexibility for the client drivers
>> or applications to set a firmware name (if needed) based on their
>> desired functionality and boot the PRU. The sysfs bind and unbind
>> attributes have also been suppressed so that the PRU devices cannot
>> be unbound and thereby shutdown a PRU from underneath a PRU client
>> driver.
>>
>> A new entry 'single_step' is added to the remoteproc debugfs dir.
>> The 'single_step' utilizes the single-step execution of the PRU
>> cores. Writing a non-zero value performs a single step, and a
>> zero value restores the PRU to execute in the same mode as the
>> mode before the first single step. (note: if the PRU is halted
>> because of a halt instruction, then no change occurs).
>>
>> pru_rproc_get() and pru_rproc_put() functions allow client drivers
>> to acquire and release the remoteproc device associated with a PRU core.
>> The PRU cores are treated as resources with only one client owning
>> it at a time.
>>
>> PRU interrupt mapping can be provided via devicetree using
>> ti,pru-interrupt-map property or via the resource table in the
>> firmware blob. If both are provided, the config in DT takes precedence.
>> For interrupt map via resource table, pru-software-support-package [1]
>> has been historically using version 0 for this. However, the current
>> data structure is not scaleable and is not self sufficient.
>> 1) it hard codes number of channel to host mappings so is not
>> scaleable to newer SoCs than have more of these.
>> 2) it does not contain the event to channel mappings within
>> itself but relies on a pointer to point to another section
>> in data memory. This causes a weird complication that the
>> respective data section must be loaded before we can really
>> use the INTC map.
>>
>> With this patch we drop support for version 0 and support
>> version 1 which is a more robust and scalable data structure.
>> It should be able to support a sufficiently large number (255) of
>> sysevents, channels and host interrupts and is self contained
>> so it can be used without dependency on order of loading sections.
> 
> Hmm, looks like you squashed a whole bunch of patches into this. I would
> prefer some of the logical ones to be separated out just like before,
> makes it easier to review the interfaces.
> 
> Looks like you have also changed usage behavior on couple of things and
> dropped some of my original changes. I was not able to test this series
> either on AM335x or on AM57xx to comment more on the behavior (not even
> seeing the pruss devices populated, not sure what pieces are missing still).

Able to get the PRUSS devices show up on AM335x atleast after enabling
the Reset Controller related configs, but no such luck on AM57xx.

regards
Suman

> 
>>
>> [1]  git://git.ti.com/pru-software-support-package/pru-software-support-package.git
>>
>> Signed-off-by: Suman Anna <[e-mail]>
>> Signed-off-by: Andrew F. Davis <[e-mail]>
>> Signed-off-by: Tero Kristo <[e-mail]>
>> Signed-off-by: Roger Quadros <[e-mail]>
>> ---

Patch

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index f0abd26..333666e 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -197,6 +197,20 @@  config ST_REMOTEPROC
 config ST_SLIM_REMOTEPROC
 	tristate
 
+config PRUSS_REMOTEPROC
+	tristate "TI PRUSS remoteproc support"
+	depends on TI_PRUSS
+	default n
+	help
+	  Support for TI PRU-ICSS remote processors via the remote processor
+	  framework.
+
+	  Currently supported on AM33xx SoCs.
+
+	  Say Y or M here to support the Programmable Realtime Unit (PRU)
+	  processors on various TI SoCs. It's safe to say N here if you're
+	  not interested in the PRU or if you are unsure.
+
 endif # REMOTEPROC
 
 endmenu
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index ce5d061..88a86cc 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -26,3 +26,4 @@  qcom_wcnss_pil-y			+= qcom_wcnss.o
 qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
 obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
 obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
+obj-$(CONFIG_PRUSS_REMOTEPROC)		+= pru_rproc.o
diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
new file mode 100644
index 0000000..ddd4b64
--- /dev/null
+++ b/drivers/remoteproc/pru_rproc.c
@@ -0,0 +1,930 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PRU-ICSS remoteproc driver for various TI SoCs
+ *
+ * Copyright (C) 2014-2019 Texas Instruments Incorporated - http://www.ti.com/
+ *	Suman Anna <[e-mail]>
+ *	Andrew F. Davis <[e-mail]>
+ */
+
+#include <linux/bitops.h>
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/irq-pruss-intc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/remoteproc.h>
+#include <linux/remoteproc/pru_rproc.h>
+#include <linux/pruss.h>
+
+#include "remoteproc_internal.h"
+#include "pru_rproc.h"
+
+/* ELF PAGE ID */
+#define PRU_PAGE_IRAM	0
+#define PRU_PAGE_DRAM	1
+
+/* IRAM offsets */
+#define PRU0_IRAM_START		0x34000
+#define PRU1_IRAM_START		0x38000
+#define PRU_IRAM_MASK		0x3ffff
+
+/* PRU_ICSS_PRU_CTRL registers */
+#define PRU_CTRL_CTRL		0x0000
+#define PRU_CTRL_STS		0x0004
+#define PRU_CTRL_WAKEUP_EN	0x0008
+#define PRU_CTRL_CYCLE		0x000C
+#define PRU_CTRL_STALL		0x0010
+#define PRU_CTRL_CTBIR0		0x0020
+#define PRU_CTRL_CTBIR1		0x0024
+#define PRU_CTRL_CTPPR0		0x0028
+#define PRU_CTRL_CTPPR1		0x002C
+
+/* CTRL register bit-fields */
+#define CTRL_CTRL_SOFT_RST_N	BIT(0)
+#define CTRL_CTRL_EN		BIT(1)
+#define CTRL_CTRL_SLEEPING	BIT(2)
+#define CTRL_CTRL_CTR_EN	BIT(3)
+#define CTRL_CTRL_SINGLE_STEP	BIT(8)
+#define CTRL_CTRL_RUNSTATE	BIT(15)
+
+/* PRU_ICSS_PRU_DEBUG registers */
+#define PRU_DEBUG_GPREG(x)	(0x0000 + (x) * 4)
+#define PRU_DEBUG_CT_REG(x)	(0x0080 + (x) * 4)
+
+/**
+ * struct pru_rproc - PRU remoteproc structure
+ * @id: id of the PRU core within the PRUSS
+ * @pruss: back-reference to parent PRUSS structure
+ * @rproc: remoteproc pointer for this PRU core
+ * @iram_region: PRU IRAM IOMEM
+ * @ctrl_regmap: regmap to PRU CTRL IOMEM
+ * @debug_regmap: regmap to PRU DEBUG IOMEM
+ * @client_np: client device node
+ * @intc_config: PRU INTC configuration data
+ * @dram0: PRUSS DRAM0 region
+ * @dram1: PRUSS DRAM1 region
+ * @shrdram: PRUSS SHARED RAM region
+ * @iram_da: device address of Instruction RAM for this PRU
+ * @pdram_da: device address of primary Data RAM for this PRU
+ * @sdram_da: device address of secondary Data RAM for this PRU
+ * @shrdram_da: device address of shared Data RAM
+ * @cfg: regmap to CFG module
+ * @gpcfg_reg: offset to gpcfg register of this PRU
+ * @fw_name: name of firmware image used during loading
+ * @gpmux_save: saved value for gpmux config
+ * @dt_irqs: number of irqs configured from DT
+ * @fw_irqs: number of irqs configured from FW
+ * @lock: mutex to protect client usage
+ * @dbg_single_step: debug state variable to set PRU into single step mode
+ * @ctrl_saved_state: saved CTRL state to return to normal mode
+ */
+struct pru_rproc {
+	int id;
+	struct pruss *pruss;
+	struct rproc *rproc;
+	struct pruss_mem_region iram_region;
+	struct regmap *ctrl_regmap;
+	struct regmap *debug_regmap;
+	struct device_node *client_np;
+	struct pruss_intc_config intc_config;
+	struct pruss_mem_region dram0;
+	struct pruss_mem_region dram1;
+	struct pruss_mem_region shrdram;
+	u32 iram_da;
+	u32 pdram_da;
+	u32 sdram_da;
+	u32 shrdram_da;
+	struct regmap *cfg;
+	int gpcfg_reg;
+	const char *fw_name;
+	u8 gpmux_save;
+	int dt_irqs;
+	int fw_irqs;
+	struct mutex lock; /* client access lock */
+	bool dbg_single_step;
+	u32 ctrl_saved_state;
+};
+
+/**
+ * pru_rproc_set_firmware() - set firmware for a pru core
+ * @rproc: the rproc instance of the PRU
+ * @fw_name: the new firmware name, or NULL if default is desired
+ */
+static int pru_rproc_set_firmware(struct rproc *rproc, const char *fw_name)
+{
+	struct pru_rproc *pru = rproc->priv;
+
+	if (!fw_name)
+		fw_name = pru->fw_name;
+
+	return rproc_set_firmware(rproc, fw_name);
+}
+
+/*
+ * pru_get_gpmux() - get the current GPMUX value for a PRU device
+ * @pru: pru_rproc instance
+ * @mux: pointer to store the current mux value into
+ *
+ * returns 0 on success, negative error value otherwise.
+ */
+static int pru_get_gpmux(struct pru_rproc *pru, u8 *mux)
+{
+	int ret;
+	unsigned int val;
+
+	ret = regmap_read(pru->cfg, pru->gpcfg_reg, &val);
+	if (ret)
+		return ret;
+
+	*mux = (u8)((val & PRUSS_GPCFG_PRU_MUX_SEL_MASK) >>
+		    PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
+
+	return 0;
+}
+
+/**
+ * pru_set_gpmux() - set the GPMUX value for a PRU device
+ * @pru: pru_rproc instance
+ * @mux: new mux value for PRU
+ *
+ * returns 0 on success, negative error value otherwise.
+ */
+static int pru_set_gpmux(struct pru_rproc *pru, u8 mux)
+{
+	if (mux >= PRUSS_GP_MUX_SEL_MAX)
+		return -EINVAL;
+
+	return regmap_update_bits(pru->cfg, pru->gpcfg_reg,
+				  PRUSS_GPCFG_PRU_MUX_SEL_MASK,
+				  (u32)mux << PRUSS_GPCFG_PRU_MUX_SEL_SHIFT);
+}
+
+static int pru_get_intc_dt_config(struct pru_rproc *pru,
+				  const char *propname, int index,
+				  struct pruss_intc_config *intc_config)
+{
+	struct device *dev = &pru->rproc->dev;
+	struct device_node *np = pru->client_np;
+	struct property *prop;
+	int ret = 0, entries, i;
+	int dt_irqs = 0;
+	u32 *arr;
+	int max_system_events, max_pru_channels, max_pru_host_ints;
+
+	max_system_events = MAX_PRU_SYS_EVENTS;
+	max_pru_channels = MAX_PRU_CHANNELS;
+	max_pru_host_ints = MAX_PRU_CHANNELS;
+
+	prop = of_find_property(np, propname, NULL);
+	if (!prop)
+		return 0;
+
+	entries = of_property_count_u32_elems(np, propname);
+	if (entries <= 0 || entries % 4)
+		return -EINVAL;
+
+	arr = kmalloc_array(entries, sizeof(u32), GFP_KERNEL);
+	if (!arr)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_array(np, propname, arr, entries);
+	if (ret)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++)
+		intc_config->sysev_to_ch[i] = -1;
+
+	for (i = 0; i < ARRAY_SIZE(intc_config->ch_to_host); i++)
+		intc_config->ch_to_host[i] = -1;
+
+	for (i = 0; i < entries; i += 4) {
+		if (arr[i] != index)
+			continue;
+
+		if (arr[i + 1] < 0 ||
+		    arr[i + 1] >= max_system_events) {
+			dev_err(dev, "bad sys event %d\n", arr[i + 1]);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (arr[i + 2] < 0 ||
+		    arr[i + 2] >= max_pru_channels) {
+			dev_err(dev, "bad channel %d\n", arr[i + 2]);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (arr[i + 3] < 0 ||
+		    arr[i + 3] >= max_pru_host_ints) {
+			dev_err(dev, "bad irq %d\n", arr[i + 3]);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		intc_config->sysev_to_ch[arr[i + 1]] = arr[i + 2];
+		dev_dbg(dev, "sysevt-to-ch[%d] -> %d\n", arr[i + 1],
+			arr[i + 2]);
+
+		intc_config->ch_to_host[arr[i + 2]] = arr[i + 3];
+		dev_dbg(dev, "chnl-to-host[%d] -> %d\n", arr[i + 2],
+			arr[i + 3]);
+
+		dt_irqs++;
+	}
+
+	kfree(arr);
+	return dt_irqs;
+
+err:
+	kfree(arr);
+	return ret;
+}
+
+static struct rproc *__pru_rproc_get(struct device_node *np, int index)
+{
+	struct device_node *rproc_np = NULL;
+	struct platform_device *pdev;
+	struct rproc *rproc;
+
+	rproc_np = of_parse_phandle(np, "prus", index);
+	if (!rproc_np || !of_device_is_available(rproc_np))
+		return ERR_PTR(-ENODEV);
+
+	pdev = of_find_device_by_node(rproc_np);
+	of_node_put(rproc_np);
+
+	if (!pdev)
+		/* probably PRU not yet probed */
+		return ERR_PTR(-EPROBE_DEFER);
+
+	/* TODO: replace the crude string based check to make sure it is PRU */
+	if (!strstr(dev_name(&pdev->dev), "pru")) {
+		put_device(&pdev->dev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	rproc = platform_get_drvdata(pdev);
+	put_device(&pdev->dev);
+	if (!rproc)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&rproc->dev);
+
+	return rproc;
+}
+
+/**
+ * pru_rproc_get() - get the PRU rproc instance from a device node
+ * @np: the user/client device node
+ * @index: index to use for the prus property
+ *
+ * This function looks through a client device node's "prus" property at index
+ * @index and returns the rproc handle for a valid PRU remote processor if
+ * found. The function allows only one user to own the PRU rproc resource at
+ * a time. Caller must call pru_rproc_put() when done with using the rproc,
+ * not required if the function returns a failure.
+ *
+ * Returns the rproc handle on success, and an ERR_PTR on failure using one
+ * of the following error values
+ *    -ENODEV if device is not found
+ *    -EBUSY if PRU is already acquired by anyone
+ *    -EPROBE_DEFER is PRU device is not probed yet
+ */
+struct rproc *pru_rproc_get(struct device_node *np, int index)
+{
+	struct rproc *rproc;
+	struct pru_rproc *pru;
+	struct device *dev;
+	int ret;
+	u32 mux;
+	const char *fw_name;
+
+	rproc = __pru_rproc_get(np, index);
+	if (IS_ERR(rproc))
+		return rproc;
+
+	pru = rproc->priv;
+	dev = &rproc->dev;
+
+	mutex_lock(&pru->lock);
+
+	if (pru->client_np) {
+		mutex_unlock(&pru->lock);
+		put_device(&rproc->dev);
+		return ERR_PTR(-EBUSY);
+	}
+
+	pru->client_np = np;
+
+	mutex_unlock(&pru->lock);
+
+	ret = pru_get_gpmux(pru, &pru->gpmux_save);
+	if (ret) {
+		dev_err(dev, "failed to get cfg gpmux: %d\n", ret);
+		goto err;
+	}
+
+	ret = of_property_read_u32_index(np, "ti,pruss-gp-mux-sel", index,
+					 &mux);
+	if (!ret) {
+		ret = pru_set_gpmux(pru, mux);
+		if (ret) {
+			dev_err(dev, "failed to set cfg gpmux: %d\n", ret);
+			goto err;
+		}
+	}
+
+	ret = of_property_read_string_index(np, "firmware-name", index,
+					    &fw_name);
+	if (!ret) {
+		ret = pru_rproc_set_firmware(rproc, fw_name);
+		if (ret) {
+			dev_err(dev, "failed to set firmware: %d\n", ret);
+			goto err;
+		}
+	}
+
+	ret = pru_get_intc_dt_config(pru, "ti,pru-interrupt-map",
+				     index, &pru->intc_config);
+	if (ret < 0) {
+		dev_err(dev, "error getting DT interrupt map: %d\n", ret);
+		goto err;
+	}
+
+	pru->dt_irqs = ret;
+
+	return rproc;
+
+err:
+	pru_rproc_put(rproc);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_get);
+
+/**
+ * pru_rproc_put() - release the PRU rproc resource
+ * @rproc: the rproc resource to release
+ *
+ * Releases the PRU rproc resource and makes it available to other
+ * users.
+ */
+void pru_rproc_put(struct rproc *rproc)
+{
+	struct pru_rproc *pru;
+
+	if (IS_ERR_OR_NULL(rproc))
+		return;
+
+	/* TODO: replace the crude string based check to make sure it is PRU */
+	if (!strstr(dev_name(rproc->dev.parent), "pru"))
+		return;
+
+	pru = rproc->priv;
+	if (!pru->client_np)
+		return;
+
+	pru_rproc_set_firmware(rproc, NULL);
+	pru_set_gpmux(pru, pru->gpmux_save);
+
+	mutex_lock(&pru->lock);
+	pru->client_np = NULL;
+	mutex_unlock(&pru->lock);
+
+	put_device(&rproc->dev);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_put);
+
+/*
+ * Control PRU single-step mode
+ *
+ * This is a debug helper function used for controlling the single-step
+ * mode of the PRU. The PRU Debug registers are not accessible when the
+ * PRU is in RUNNING state.
+ *
+ * Writing a non-zero value sets the PRU into single-step mode irrespective
+ * of its previous state. The PRU mode is saved only on the first set into
+ * a single-step mode. Writing a zero value will restore the PRU into its
+ * original mode.
+ */
+static int pru_rproc_debug_ss_set(void *data, u64 val)
+{
+	struct rproc *rproc = data;
+	struct pru_rproc *pru = rproc->priv;
+	u32 reg_val;
+	bool debug_ss;
+
+	debug_ss = !!val;
+	if (!debug_ss && !pru->dbg_single_step)
+		return 0;
+
+	regmap_read(pru->ctrl_regmap, PRU_CTRL_CTRL, &reg_val);
+
+	if (debug_ss && !pru->dbg_single_step)
+		pru->ctrl_saved_state = reg_val;
+
+	if (debug_ss)
+		reg_val |= CTRL_CTRL_SINGLE_STEP | CTRL_CTRL_EN;
+	else
+		reg_val = pru->ctrl_saved_state;
+
+	pru->dbg_single_step = debug_ss;
+	regmap_write(pru->ctrl_regmap, PRU_CTRL_CTRL, reg_val);
+
+	return 0;
+}
+
+static int pru_rproc_debug_ss_get(void *data, u64 *val)
+{
+	struct rproc *rproc = data;
+	struct pru_rproc *pru = rproc->priv;
+
+	*val = pru->dbg_single_step;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(pru_rproc_debug_ss_fops, pru_rproc_debug_ss_get,
+			pru_rproc_debug_ss_set, "%llu\n");
+
+/*
+ * Create PRU-specific debugfs entries
+ *
+ * The entries are created only if the parent remoteproc debugfs directory
+ * exists, and will be cleaned up by the remoteproc core.
+ */
+static void pru_rproc_create_debug_entries(struct rproc *rproc)
+{
+	if (!rproc->dbg_dir)
+		return;
+
+	debugfs_create_file("single_step", 0600, rproc->dbg_dir,
+			    rproc, &pru_rproc_debug_ss_fops);
+}
+
+static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, int len);
+
+/*
+ * parse the custom interrupt map resource and save the intc_config
+ * for use when booting the processor.
+ */
+static int pru_handle_vendor_intrmap(struct rproc *rproc,
+				     struct fw_rsc_pruss_intrmap *rsc)
+{
+	int fw_irqs = 0, i, ret = 0;
+	u8 *arr;
+	struct device *dev = &rproc->dev;
+	struct pru_rproc *pru = rproc->priv;
+
+	dev_dbg(dev, "vendor rsc intc: version %d\n", rsc->version);
+
+	/*
+	 * 0 was prototyping version. Not supported.
+	 * 1 is currently supported version.
+	 */
+	if (rsc->version == 0 || rsc->version > 1) {
+		dev_err(dev, "Unsupported version %d\n", rsc->version);
+		return -EINVAL;
+	}
+
+	/* DT provided INTC config takes precedence */
+	if (pru->dt_irqs) {
+		dev_info(dev, "INTC config in DT and FW. Using DT config.\n");
+		return 0;
+	}
+
+	arr = rsc->data;
+
+	for (i = 0; i < ARRAY_SIZE(pru->intc_config.sysev_to_ch); i++)
+		pru->intc_config.sysev_to_ch[i] = -1;
+
+	for (i = 0; i < ARRAY_SIZE(pru->intc_config.ch_to_host); i++)
+		pru->intc_config.ch_to_host[i] = -1;
+
+	for (i = 0; i < rsc->num_maps * 3; i += 3) {
+		if (arr[i] < 0 ||
+		    arr[i] >= MAX_PRU_SYS_EVENTS) {
+			dev_err(dev, "bad sys event %d\n", arr[i]);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (arr[i + 1] < 0 ||
+		    arr[i + 1] >= MAX_PRU_CHANNELS) {
+			dev_err(dev, "bad channel %d\n", arr[i + 1]);
+			ret = -EINVAL;
+			goto err;
+		}
+
+		if (arr[i + 2] < 0 ||
+		    arr[i + 2] >= MAX_PRU_CHANNELS) {
+			dev_err(dev, "bad host irq %d\n", arr[i + 2]);
+				ret = -EINVAL;
+			goto err;
+		}
+
+		pru->intc_config.sysev_to_ch[arr[i]] = arr[i + 1];
+		dev_dbg(dev, "sysevt-to-ch[%d] -> %d\n", arr[i],
+			arr[i + 1]);
+
+		pru->intc_config.ch_to_host[arr[i + 1]] = arr[i + 2];
+		dev_dbg(dev, "chnl-to-host[%d] -> %d\n", arr[i + 1],
+			arr[i + 2]);
+
+		fw_irqs++;
+	}
+
+	pru->fw_irqs = fw_irqs;
+	return 0;
+
+err:
+	pru->fw_irqs = 0;
+	return ret;
+}
+
+/* PRU-specific vendor resource handler */
+static int pru_rproc_handle_vendor_rsc(struct rproc *rproc,
+				       struct fw_rsc_vendor *ven_rsc)
+{
+	struct device *dev = rproc->dev.parent;
+	int ret = -EINVAL;
+
+	struct fw_rsc_pruss_intrmap *rsc;
+
+	rsc = (struct fw_rsc_pruss_intrmap *)ven_rsc->data;
+
+	switch (rsc->type) {
+	case PRUSS_RSC_INTRS:
+		ret = pru_handle_vendor_intrmap(rproc, rsc);
+		break;
+	default:
+		dev_err(dev, "%s: cannot handle unknown type %d\n", __func__,
+			rsc->type);
+	}
+
+	return ret;
+}
+
+/* start a PRU core */
+static int pru_rproc_start(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	struct pru_rproc *pru = rproc->priv;
+	u32 val;
+	int ret;
+
+	dev_dbg(dev, "starting PRU%d: entry-point = 0x%x\n",
+		pru->id, (rproc->bootaddr >> 2));
+
+	if (pru->dt_irqs || pru->fw_irqs) {
+		ret = pruss_intc_configure(rproc->dev.parent,
+					   &pru->intc_config);
+		if (ret) {
+			dev_err(dev, "failed to configure intc %d\n", ret);
+			return ret;
+		}
+	}
+
+	val = CTRL_CTRL_EN | ((rproc->bootaddr >> 2) << 16);
+	regmap_write(pru->ctrl_regmap, PRU_CTRL_CTRL, val);
+
+	return 0;
+}
+
+/* stop/disable a PRU core */
+static int pru_rproc_stop(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	struct pru_rproc *pru = rproc->priv;
+
+	dev_dbg(dev, "stopping PRU%d\n", pru->id);
+	regmap_update_bits(pru->ctrl_regmap, PRU_CTRL_CTRL, CTRL_CTRL_EN, 0);
+
+	/* undo INTC config */
+	if (pru->dt_irqs || pru->fw_irqs)
+		pruss_intc_unconfigure(rproc->dev.parent, &pru->intc_config);
+
+	return 0;
+}
+
+/*
+ * Convert PRU device address (data spaces only) to kernel virtual address
+ *
+ * Each PRU has access to all data memories within the PRUSS, accessible at
+ * different ranges. So, look through both its primary and secondary Data
+ * RAMs as well as any shared Data RAM to convert a PRU device address to
+ * kernel virtual address. Data RAM0 is primary Data RAM for PRU0 and Data
+ * RAM1 is primary Data RAM for PRU1.
+ */
+static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, int len)
+{
+	struct pruss_mem_region dram0, dram1, shrd_ram;
+	u32 offset;
+	void *va = NULL;
+
+	if (len <= 0)
+		return NULL;
+
+	dram0 = pru->dram0;
+	dram1 = pru->dram1;
+	/* PRU1 has its local RAM addresses reversed */
+	if (pru->id == 1)
+		swap(dram0, dram1);
+	shrd_ram = pru->shrdram;
+
+	if (da >= pru->pdram_da && da + len <= pru->pdram_da + dram0.size) {
+		offset = da - pru->pdram_da;
+		va = (__force void *)(dram0.va + offset);
+	} else if (da >= pru->sdram_da &&
+		   da + len <= pru->sdram_da + dram1.size) {
+		offset = da - pru->sdram_da;
+		va = (__force void *)(dram1.va + offset);
+	} else if (da >= pru->shrdram_da &&
+		   da + len <= pru->shrdram_da + shrd_ram.size) {
+		offset = da - pru->shrdram_da;
+		va = (__force void *)(shrd_ram.va + offset);
+	}
+
+	return va;
+}
+
+/*
+ * Convert PRU device address (instruction space) to kernel virtual address
+ *
+ * A PRU does not have an unified address space. Each PRU has its very own
+ * private Instruction RAM, and its device address is identical to that of
+ * its primary Data RAM device address.
+ */
+static void *pru_i_da_to_va(struct pru_rproc *pru, u32 da, int len)
+{
+	u32 offset;
+	void *va = NULL;
+
+	if (len <= 0)
+		return NULL;
+
+	if (da >= pru->iram_da &&
+	    da + len <= pru->iram_da + pru->iram_region.size) {
+		offset = da - pru->iram_da;
+		va = (__force void *)(pru->iram_region.va + offset);
+	}
+
+	return va;
+}
+
+/* PRU-specific address translator */
+static void *pru_da_to_va(struct rproc *rproc, u64 da, int len, int map)
+{
+	struct pru_rproc *pru = rproc->priv;
+	void *va;
+
+	switch (map) {
+	case PRU_PAGE_IRAM:
+		va = pru_i_da_to_va(pru, da, len);
+		break;
+	case PRU_PAGE_DRAM:
+		va = pru_d_da_to_va(pru, da, len);
+		break;
+	default:
+		dev_info(&rproc->dev, "%s: invalid page %d\n", __func__, map);
+		return 0;
+	};
+
+	return va;
+}
+
+static struct rproc_ops pru_rproc_ops = {
+	.start			= pru_rproc_start,
+	.stop			= pru_rproc_stop,
+	.da_to_va		= pru_da_to_va,
+	.handle_vendor_rsc	= pru_rproc_handle_vendor_rsc,
+};
+
+static int pru_rproc_set_id(struct pru_rproc *pru)
+{
+	int ret = 0;
+	u32 iram_start = pru->iram_region.pa & PRU_IRAM_MASK;
+
+	if (iram_start == PRU0_IRAM_START)
+		pru->id = 0;
+	else if (iram_start == PRU1_IRAM_START)
+		pru->id = 1;
+	else
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static struct regmap_config pru_ctrl_regmap_config = {
+	.name = "ctrl",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = PRU_CTRL_CTPPR1,
+};
+
+static struct regmap_config pru_debug_regmap_config = {
+	.name = "debug",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = PRU_DEBUG_CT_REG(31),
+};
+
+static int pru_rproc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct platform_device *ppdev = to_platform_device(dev->parent);
+	struct pru_rproc *pru;
+	const char *fw_name;
+	struct rproc *rproc = NULL;
+	struct resource *res;
+	int ret;
+	void __iomem *va;
+
+	if (!np) {
+		dev_err(dev, "Non-DT platform device not supported\n");
+		return -ENODEV;
+	}
+
+	ret = of_property_read_string(np, "firmware-name", &fw_name);
+	if (ret) {
+		dev_err(dev, "unable to retrieve firmware-name %d\n", ret);
+		return ret;
+	}
+
+	rproc = rproc_alloc(dev, pdev->name, &pru_rproc_ops, fw_name,
+			    sizeof(*pru));
+	if (!rproc) {
+		dev_err(dev, "rproc_alloc failed\n");
+		return -ENOMEM;
+	}
+
+	pru = rproc->priv;
+	pru->cfg = syscon_regmap_lookup_by_phandle(np, "gpcfg");
+	if (IS_ERR(pru->cfg)) {
+		if (PTR_ERR(pru->cfg) != -EPROBE_DEFER)
+			dev_err(dev, "can't get gpcfg syscon regmap\n");
+
+		return PTR_ERR(pru->cfg);
+	}
+
+	if (of_property_read_u32_index(np, "gpcfg", 1, &pru->gpcfg_reg)) {
+		dev_err(dev, "couldn't get gpcfg reg. offset\n");
+		return -EINVAL;
+	}
+
+	/* error recovery is not supported for PRUs */
+	rproc->recovery_disabled = true;
+
+	/*
+	 * rproc_add will auto-boot the processor normally, but this is
+	 * not desired with PRU client driven boot-flow methodology. A PRU
+	 * application/client driver will boot the corresponding PRU
+	 * remote-processor as part of its state machine either through
+	 * the remoteproc sysfs interface or through the equivalent kernel API
+	 */
+	rproc->auto_boot = false;
+
+	pru->pruss = platform_get_drvdata(ppdev);
+	pru->rproc = rproc;
+	pru->fw_name = fw_name;
+	mutex_init(&pru->lock);
+
+	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_DRAM0,
+				       &pru->dram0);
+	if (ret) {
+		dev_err(dev, "couldn't get PRUSS DRAM0: %d\n", ret);
+		return ret;
+	}
+	pruss_release_mem_region(pru->pruss, &pru->dram0);
+
+	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_DRAM1,
+				       &pru->dram1);
+	if (ret) {
+		dev_err(dev, "couldn't get PRUSS DRAM1: %d\n", ret);
+		return ret;
+	}
+	pruss_release_mem_region(pru->pruss, &pru->dram1);
+
+	ret = pruss_request_mem_region(pru->pruss, PRUSS_MEM_SHRD_RAM2,
+				       &pru->shrdram);
+	if (ret) {
+		dev_err(dev, "couldn't get PRUSS Shared RAM: %d\n", ret);
+		return ret;
+	}
+	pruss_release_mem_region(pru->pruss, &pru->shrdram);
+
+	/* XXX: get this from match data if different in the future */
+	pru->iram_da = 0;
+	pru->pdram_da = 0;
+	pru->sdram_da = 0x2000;
+	pru->shrdram_da = 0x10000;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "iram");
+	pru->iram_region.va = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pru->iram_region.va)) {
+		ret = PTR_ERR(pru->iram_region.va);
+		dev_err(dev, "failed to get iram resource: %d\n", ret);
+		goto free_rproc;
+	}
+
+	pru->iram_region.pa = res->start;
+	pru->iram_region.size = resource_size(res);
+
+	dev_dbg(dev, "iram: pa %pa size 0x%zx va %p\n",
+		&pru->iram_region.pa, pru->iram_region.size,
+		pru->iram_region.va);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control");
+	va = devm_ioremap_resource(dev, res);
+	if (IS_ERR(va)) {
+		ret = PTR_ERR(va);
+		dev_err(dev, "failed to get control resource: %d\n", ret);
+		goto free_rproc;
+	}
+
+	pru->ctrl_regmap = devm_regmap_init_mmio(dev, va,
+						 &pru_ctrl_regmap_config);
+	if (IS_ERR(pru->ctrl_regmap)) {
+		ret = PTR_ERR(pru->ctrl_regmap);
+		dev_err(dev, "CTRL regmap init failed: %d\n", ret);
+		goto free_rproc;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "debug");
+	va = devm_ioremap_resource(dev, res);
+	if (IS_ERR(va)) {
+		ret = PTR_ERR(va);
+		dev_err(dev, "failed to get debug resource: %d\n", ret);
+		goto free_rproc;
+	}
+	pru->debug_regmap = devm_regmap_init_mmio(dev, va,
+						  &pru_debug_regmap_config);
+	if (IS_ERR(pru->debug_regmap)) {
+		ret = PTR_ERR(pru->debug_regmap);
+		dev_err(dev, "DEBUG regmap init failed: %d\n", ret);
+		goto free_rproc;
+	}
+
+	ret = pru_rproc_set_id(pru);
+	if (ret < 0)
+		goto free_rproc;
+
+	platform_set_drvdata(pdev, rproc);
+
+	ret = rproc_add(pru->rproc);
+	if (ret) {
+		dev_err(dev, "rproc_add failed: %d\n", ret);
+		goto free_rproc;
+	}
+
+	pru_rproc_create_debug_entries(rproc);
+
+	dev_info(dev, "PRU rproc node %s probed successfully\n", np->full_name);
+
+	return 0;
+
+free_rproc:
+	rproc_free(rproc);
+	return ret;
+}
+
+static int pru_rproc_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rproc *rproc = platform_get_drvdata(pdev);
+
+	dev_info(dev, "%s: removing rproc %s\n", __func__, rproc->name);
+
+	rproc_del(rproc);
+	rproc_free(rproc);
+
+	return 0;
+}
+
+static const struct of_device_id pru_rproc_match[] = {
+	{ .compatible = "ti,am3356-pru", },
+	{ .compatible = "ti,am4376-pru", },
+	{ .compatible = "ti,am5728-pru", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pru_rproc_match);
+
+static struct platform_driver pru_rproc_driver = {
+	.driver = {
+		.name   = "pru-rproc",
+		.of_match_table = pru_rproc_match,
+		.suppress_bind_attrs = true,
+	},
+	.probe  = pru_rproc_probe,
+	.remove = pru_rproc_remove,
+};
+module_platform_driver(pru_rproc_driver);
+
+MODULE_AUTHOR("Suman Anna <[e-mail]>");
+MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/remoteproc/pru_rproc.h b/drivers/remoteproc/pru_rproc.h
new file mode 100644
index 0000000..bbcf392
--- /dev/null
+++ b/drivers/remoteproc/pru_rproc.h
@@ -0,0 +1,54 @@ 
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * PRUSS Remote Processor specific types
+ *
+ * Copyright (C) 2014-2019 Texas Instruments Incorporated - http://www.ti.com/
+ * All rights reserved.
+ */
+
+#ifndef _PRU_REMOTEPROC_H_
+#define _PRU_REMOTEPROC_H_
+
+/**
+ * enum pruss_rsc_types - PRU specific resource types
+ *
+ * @PRUSS_RSC_INTRS: Resource holding information on PRU PINTC configuration
+ * @PRUSS_RSC_MAX: Indicates end of known/defined PRU resource types.
+ *		   This should be the last definition.
+ *
+ * Introduce new custom resource types before PRUSS_RSC_MAX.
+ */
+enum pruss_rsc_types {
+	PRUSS_RSC_INTRS	= 1,
+	PRUSS_RSC_MAX	= 2,
+};
+
+/**
+ * struct fw_rsc_pruss_intrmap - vendor resource to define PRU interrupts
+ * @type: should be PRUSS_RSC_INTRS
+ * @version: should be 1 or greater. 0 was for prototyping and is not supported
+ * @num_maps: number of interrupt mappings that follow
+ * @data: Array of 'num_maps' mappings.
+ *		Each mapping is a triplet {s, c, h}
+ *		s - system event id
+ *		c - channel id
+ *		h - host interrupt id
+ *
+ * PRU system events are mapped to channels, and these channels are mapped
+ * to host interrupts. Events can be mapped to channels in a one-to-one or
+ * many-to-one ratio (multiple events per channel), and channels can be
+ * mapped to host interrupts in a one-to-one or many-to-one ratio (multiple
+ * channels per interrupt).
+ *
+ * This resource is variable length due to the nature of INTC map.
+ * The below data structure is scalable so it can support sufficiently
+ * large number of sysevents and hosts.
+ */
+struct fw_rsc_pruss_intrmap {
+	u16 type;
+	u16 version;
+	u8 num_maps;
+	u8 data[];
+} __packed;
+
+#endif	/* _PRU_REMOTEPROC_H_ */
diff --git a/include/linux/remoteproc/pru_rproc.h b/include/linux/remoteproc/pru_rproc.h
new file mode 100644
index 0000000..841da09
--- /dev/null
+++ b/include/linux/remoteproc/pru_rproc.h
@@ -0,0 +1,27 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/**
+ * PRU-ICSS Remote Subsystem user interfaces
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
+ */
+
+#ifndef __LINUX_REMOTEPROC_PRU_RPROC_H
+#define __LINUX_REMOTEPROC_PRU_RPROC_H
+
+#if IS_ENABLED(CONFIG_PRUSS_REMOTEPROC)
+
+struct rproc *pru_rproc_get(struct device_node *node, int index);
+void pru_rproc_put(struct rproc *rproc);
+
+#else
+
+static inline struct rproc *pru_rproc_get(struct device_node *node, int index)
+{
+	return ERR_PTR(-ENOTSUPP);
+}
+
+static inline void pru_rproc_put(struct rproc *rproc) { }
+
+#endif /* CONFIG_PRUSS_REMOTEPROC */
+
+#endif /* __LINUX_REMOTEPROC_PRU_RPROC_H */