[PATCH v3 0/2] Initial Renesas R-Car remoteproc support

[PATCH v3 0/2] Initial Renesas R-Car remoteproc support

[Julien Massot]

Most of the SoCs in the R-Car gen3 SoC series such as
H3,M3 and E3 have an 'Arm Realtime Core'.
This Realtime core is an Arm Cortex-R7 clocked at 800MHz.
This series adds initial support to load a firmware and start
this remote processor through the remoteproc subsystem.

This series depends on
https://patchwork.kernel.org/project/linux-renesas-soc/patch/20211022122101.66998-1-julien.massot@iot.bzh/
to be able to set the Cortex-R7 boot address.

One of the way to test this driver is to use the zephyr upstream support
for h3ulcb board 'blinky' demo is my favorite testing firmware.

To generate a firmware with the zephyr project.

follow this starting guide
https://docs.zephyrproject.org/2.7.0/getting_started/index.html

Then compile your zephyr demo
west build -b rcar_h3ulcb_cr7 zephyr/samples/basic/blinky \
    -DCONFIG_KERNEL_ENTRY=\"_vector_table\" \
    --build-dir h3-blinky

Then you can use h3-blinky/zephyr/zephyr.elf as a testing
firmware.

Patch 1/2 adds the dt-bindings

Patch 2/2 is a small driver to cover basic remoteproc
usage: loading firmware from filesystem, starting and stopping the
Cortex-r7 processor.

Julien Massot (2):
  dt-bindings: remoteproc: Add Renesas R-Car
  remoteproc: Add Renesas rcar driver

 .../remoteproc/renesas,rcar-rproc.yaml        |  65 +++++
 drivers/remoteproc/Kconfig                    |  11 +
 drivers/remoteproc/Makefile                   |   1 +
 drivers/remoteproc/rcar_rproc.c               | 223 ++++++++++++++++++
 4 files changed, 300 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml
 create mode 100644 drivers/remoteproc/rcar_rproc.c

-- 
2.33.1

[PATCH v3 1/2] dt-bindings: remoteproc: Add Renesas R-Car

[Julien Massot]

Renesas R-Car SoCs may contain a Realtime processor.
This patch adds bindings for this remote processor.

Signed-off-by: Julien Massot <julien.massot@iot.bzh>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---

Changes since v2:
Fix spelling

---
 .../remoteproc/renesas,rcar-rproc.yaml        | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml

diff --git a/Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml
new file mode 100644
index 000000000000..a7d25fa920e5
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/remoteproc/renesas,rcar-rproc.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Renesas R-Car remote processor controller bindings
+
+maintainers:
+  - Julien Massot <julien.massot@iot.bzh>
+
+description: |
+  This document defines the bindings for the remoteproc component that loads and
+  boots firmwares on the Renesas R-Car family chipset.
+  R-Car gen3 family may have a realtime processor, this processor shares peripheral
+  and RAM with the host processor with the same address map.
+
+properties:
+  compatible:
+    const: renesas,rcar-cr7
+
+  resets:
+    maxItems: 1
+
+  power-domains:
+    maxItems: 1
+
+  memory-region:
+    description:
+      List of phandles to the reserved memory regions associated with the
+      remoteproc device. This is variable and describes the memories shared with
+      the remote processor (e.g. remoteproc firmware and carveouts, rpmsg
+      vrings, ...).
+      (see ../reserved-memory/reserved-memory.yaml)
+
+required:
+  - compatible
+  - resets
+  - memory-region
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/r8a7795-cpg-mssr.h>
+    #include <dt-bindings/power/r8a7795-sysc.h>
+    reserved-memory {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        cr7_ram: cr7_ram@40040000 {
+            no-map;
+            reg = <0x0 0x40040000 0x0 0x1fc0000>;
+        };
+    };
+
+    cr7_rproc: cr7 {
+        compatible = "renesas,rcar-cr7";
+        memory-region = <&cr7_ram>;
+        power-domains = <&sysc R8A7795_PD_CR7>;
+        resets = <&cpg 222>;
+    };
+
+...
-- 
2.33.1

[PATCH v3 2/2] remoteproc: Add Renesas rcar driver

[Julien Massot]

Renesas Gen3 platform includes a Cortex-r7 processor.

Both: the application cores (A5x) and the realtime core (CR7)
share access to the RAM and devices with the same address map,
so device addresses are equal to the Linux physical addresses.

In order to initialize this remote processor we need to:
- power on the realtime core
- put the firmware in a RAM area
- set the boot address for this firmware (reset vector)
- Deassert the reset

This initial driver allows to start and stop the Cortex R7
processor.

Signed-off-by: Julien Massot <julien.massot@iot.bzh>
---
Changes since v2:
Address Geert's comments
- Remove unecessay cast
- Use devm_rproc_add/alloc
- Add sanity check when truncating u64 address to u32
- Some spelling fix

---
 drivers/remoteproc/Kconfig      |  11 ++
 drivers/remoteproc/Makefile     |   1 +
 drivers/remoteproc/rcar_rproc.c | 224 ++++++++++++++++++++++++++++++++
 3 files changed, 236 insertions(+)
 create mode 100644 drivers/remoteproc/rcar_rproc.c

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index f2e961f998ca..3ddd426fc969 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -283,6 +283,17 @@ config QCOM_WCNSS_PIL
 	  verified and booted with the help of the Peripheral Authentication
 	  System (PAS) in TrustZone.
 
+config RCAR_REMOTEPROC
+	tristate "Renesas R-Car Gen3 remoteproc support"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  Say y here to support R-Car realtime processor via the
+	  remote processor framework. An ELF firmware can be loaded
+	  thanks to sysfs remoteproc entries. The remote processor
+	  can be started and stopped.
+	  This can be either built-in or a loadable module.
+	  If compiled as module (M), the module name is rcar_rproc.
+
 config ST_REMOTEPROC
 	tristate "ST remoteproc support"
 	depends on ARCH_STI
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 0ac256b6c977..5478c7cb9e07 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_QCOM_SYSMON)		+= qcom_sysmon.o
 obj-$(CONFIG_QCOM_WCNSS_PIL)		+= qcom_wcnss_pil.o
 qcom_wcnss_pil-y			+= qcom_wcnss.o
 qcom_wcnss_pil-y			+= qcom_wcnss_iris.o
+obj-$(CONFIG_RCAR_REMOTEPROC)		+= rcar_rproc.o
 obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
 obj-$(CONFIG_ST_SLIM_REMOTEPROC)	+= st_slim_rproc.o
 obj-$(CONFIG_STM32_RPROC)		+= stm32_rproc.o
diff --git a/drivers/remoteproc/rcar_rproc.c b/drivers/remoteproc/rcar_rproc.c
new file mode 100644
index 000000000000..34fd867f9f8c
--- /dev/null
+++ b/drivers/remoteproc/rcar_rproc.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) IoT.bzh 2021
+ */
+
+#include <linux/limits.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/pm_runtime.h>
+#include <linux/remoteproc.h>
+#include <linux/reset.h>
+#include <linux/soc/renesas/rcar-rst.h>
+
+#include "remoteproc_internal.h"
+
+struct rcar_rproc {
+	struct reset_control *rst;
+};
+
+static int rcar_rproc_mem_alloc(struct rproc *rproc,
+				 struct rproc_mem_entry *mem)
+{
+	struct device *dev = &rproc->dev;
+	void *va;
+
+	dev_dbg(dev, "map memory: %pa+%zx\n", &mem->dma, mem->len);
+	va = ioremap_wc(mem->dma, mem->len);
+	if (!va) {
+		dev_err(dev, "Unable to map memory region: %pa+%zx\n",
+			&mem->dma, mem->len);
+		return -ENOMEM;
+	}
+
+	/* Update memory entry va */
+	mem->va = va;
+
+	return 0;
+}
+
+static int rcar_rproc_mem_release(struct rproc *rproc,
+				   struct rproc_mem_entry *mem)
+{
+	dev_dbg(&rproc->dev, "unmap memory: %pa\n", &mem->dma);
+	iounmap(mem->va);
+
+	return 0;
+}
+
+static int rcar_rproc_prepare(struct rproc *rproc)
+{
+	struct device *dev = rproc->dev.parent;
+	struct device_node *np = dev->of_node;
+	struct of_phandle_iterator it;
+	struct rproc_mem_entry *mem;
+	struct reserved_mem *rmem;
+	u32 da;
+
+	/* Register associated reserved memory regions */
+	of_phandle_iterator_init(&it, np, "memory-region", NULL, 0);
+	while (of_phandle_iterator_next(&it) == 0) {
+
+		rmem = of_reserved_mem_lookup(it.node);
+		if (!rmem) {
+			dev_err(&rproc->dev,
+				"unable to acquire memory-region\n");
+			return -EINVAL;
+		}
+
+		if (rmem->base > U32_MAX)
+			return -EINVAL;
+
+		/* No need to translate pa to da, R-Car use same map */
+		da = rmem->base;
+		mem = rproc_mem_entry_init(dev, NULL,
+					   rmem->base,
+					   rmem->size, da,
+					   rcar_rproc_mem_alloc,
+					   rcar_rproc_mem_release,
+					   it.node->name);
+
+		if (!mem)
+			return -ENOMEM;
+
+		rproc_add_carveout(rproc, mem);
+	}
+
+	return 0;
+}
+
+static int rcar_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
+{
+	int ret;
+
+	ret = rproc_elf_load_rsc_table(rproc, fw);
+	if (ret)
+		dev_info(&rproc->dev, "No resource table in elf\n");
+
+	return 0;
+}
+
+static int rcar_rproc_start(struct rproc *rproc)
+{
+	struct rcar_rproc *priv = rproc->priv;
+	int err;
+
+	if (!rproc->bootaddr)
+		return -EINVAL;
+
+	err = rcar_rst_set_rproc_boot_addr(rproc->bootaddr);
+	if (err) {
+		dev_err(&rproc->dev, "failed to set rproc boot addr\n");
+		return err;
+	}
+
+	err = reset_control_deassert(priv->rst);
+	if (err)
+		dev_err(&rproc->dev, "failed to deassert reset\n");
+
+	return err;
+}
+
+static int rcar_rproc_stop(struct rproc *rproc)
+{
+	struct rcar_rproc *priv = rproc->priv;
+	int err;
+
+	err = reset_control_assert(priv->rst);
+	if (err)
+		dev_err(&rproc->dev, "failed to assert reset\n");
+
+	return err;
+}
+
+static struct rproc_ops rcar_rproc_ops = {
+	.prepare	= rcar_rproc_prepare,
+	.start		= rcar_rproc_start,
+	.stop		= rcar_rproc_stop,
+	.load		= rproc_elf_load_segments,
+	.parse_fw	= rcar_rproc_parse_fw,
+	.find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
+	.sanity_check	= rproc_elf_sanity_check,
+	.get_boot_addr	= rproc_elf_get_boot_addr,
+
+};
+
+static int rcar_rproc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct rcar_rproc *priv;
+	struct rproc *rproc;
+	int ret;
+
+	rproc = devm_rproc_alloc(dev, np->name, &rcar_rproc_ops,
+				NULL, sizeof(*priv));
+	if (!rproc)
+		return -ENOMEM;
+
+	priv = rproc->priv;
+
+	priv->rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->rst)) {
+		ret = PTR_ERR(priv->rst);
+		dev_err_probe(dev, ret, "fail to acquire rproc reset\n");
+		return ret;;
+	}
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret) {
+		dev_err(dev, "failed to power up\n");
+		return ret;
+	}
+
+	dev_set_drvdata(dev, rproc);
+
+	/* Manually start the rproc */
+	rproc->auto_boot = false;
+
+	ret = devm_rproc_add(dev, rproc);
+	if (ret) {
+		dev_err(dev, "rproc_add failed\n");
+		goto pm_disable;
+	}
+
+	return 0;
+
+pm_disable:
+	pm_runtime_disable(dev);
+
+	return ret;
+}
+
+static int rcar_rproc_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	pm_runtime_disable(dev);
+
+	return 0;
+}
+
+static const struct of_device_id rcar_rproc_of_match[] = {
+	{ .compatible = "renesas,rcar-cr7" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, rcar_rproc_of_match);
+
+static struct platform_driver rcar_rproc_driver = {
+	.probe = rcar_rproc_probe,
+	.remove = rcar_rproc_remove,
+	.driver = {
+		.name = "rcar-rproc",
+		.of_match_table = rcar_rproc_of_match,
+	},
+};
+
+module_platform_driver(rcar_rproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Renesas R-Car Gen3 remote processor control driver");
+MODULE_AUTHOR("Julien Massot <julien.massot@iot.bzh>");
-- 
2.33.1

Re: [PATCH v3 0/2] Initial Renesas R-Car remoteproc support

[Mathieu Poirier]

On Tue, Dec 07, 2021 at 05:58:27PM +0100, Julien Massot wrote:
> Most of the SoCs in the R-Car gen3 SoC series such as
> H3,M3 and E3 have an 'Arm Realtime Core'.
> This Realtime core is an Arm Cortex-R7 clocked at 800MHz.
> This series adds initial support to load a firmware and start
> this remote processor through the remoteproc subsystem.
> 
> This series depends on
> https://patchwork.kernel.org/project/linux-renesas-soc/patch/20211022122101.66998-1-julien.massot@iot.bzh/
> to be able to set the Cortex-R7 boot address.
> 
> One of the way to test this driver is to use the zephyr upstream support
> for h3ulcb board 'blinky' demo is my favorite testing firmware.
> 
> To generate a firmware with the zephyr project.
> 
> follow this starting guide
> https://docs.zephyrproject.org/2.7.0/getting_started/index.html
> 
> Then compile your zephyr demo
> west build -b rcar_h3ulcb_cr7 zephyr/samples/basic/blinky \
>     -DCONFIG_KERNEL_ENTRY=\"_vector_table\" \
>     --build-dir h3-blinky
> 
> Then you can use h3-blinky/zephyr/zephyr.elf as a testing
> firmware.
> 
> Patch 1/2 adds the dt-bindings
> 
> Patch 2/2 is a small driver to cover basic remoteproc
> usage: loading firmware from filesystem, starting and stopping the
> Cortex-r7 processor.
> 
> Julien Massot (2):
>   dt-bindings: remoteproc: Add Renesas R-Car
>   remoteproc: Add Renesas rcar driver
> 
>  .../remoteproc/renesas,rcar-rproc.yaml        |  65 +++++
>  drivers/remoteproc/Kconfig                    |  11 +
>  drivers/remoteproc/Makefile                   |   1 +
>  drivers/remoteproc/rcar_rproc.c               | 223 ++++++++++++++++++

I have applied this set.

Thanks,
Mathieu

>  4 files changed, 300 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/renesas,rcar-rproc.yaml
>  create mode 100644 drivers/remoteproc/rcar_rproc.c
> 
> -- 
> 2.33.1
> 
>