[PATCH v4 0/6] Introduce PRU remoteproc consumer API

[PATCH v4 0/6] Introduce PRU remoteproc consumer API

[Puranjay Mohan]

This is the v4 of the patch series [1]. The v3 had some comments
on the DT patch that have been addressed here. The 6th patch in this
series was missed in the previous versions, so, it has been added now.

I have posted two more patch series that depend on this series, one to
the soc tree and another to the networking tree. I had sent all the 3
series, including this one as RFC [2] to get comments and to explain the
dependencies.

The Programmable Real-Time Unit and Industrial Communication Subsystem
(PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
RISC cores (Programmable Real-Time Units, or PRUs) for program execution.

There are 3 foundation components for PRUSS subsystem: the PRUSS platform
driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
already merged and can be found under:
1) drivers/soc/ti/pruss.c
   Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
2) drivers/irqchip/irq-pruss-intc.c
   Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
3) drivers/remoteproc/pru_rproc.c
   Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml

The programmable nature of the PRUs provide flexibility to implement custom
peripheral interfaces, fast real-time responses, or specialized data handling.
Example of a PRU consumer drivers will be:
  - Software UART over PRUSS
  - PRU-ICSS Ethernet EMAC

In order to make usage of common PRU resources and allow the consumer drivers to
configure the PRU hardware for specific usage the PRU API is introduced.

[1] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220418104118.12878-1-p-mohan@ti.com/
[2] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220406094358.7895-1-p-mohan@ti.com/

Thanks and Regards,
Puranjay Mohan

Roger Quadros (1):
  remoteproc: pru: Add pru_rproc_set_ctable() function

Suman Anna (2):
  dt-bindings: remoteproc: Add PRU consumer bindings
  remoteproc: pru: Make sysfs entries read-only for PRU client driven
    boots

Tero Kristo (3):
  remoteproc: pru: Add APIs to get and put the PRU cores
  remoteproc: pru: Configure firmware based on client setup
  remoteproc: pru: add support for configuring GPMUX based on client
    setup

 .../bindings/remoteproc/ti,pru-consumer.yaml  |  69 +++++
 drivers/remoteproc/pru_rproc.c                | 254 +++++++++++++++++-
 include/linux/pruss.h                         |  78 ++++++
 3 files changed, 396 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
 create mode 100644 include/linux/pruss.h

-- 
2.17.1

[PATCH v4 1/6] dt-bindings: remoteproc: Add PRU consumer bindings

[Puranjay Mohan]

From: Suman Anna <s-anna@ti.com>

Add a YAML binding document for PRU consumers. The binding includes
all the common properties that can be used by different PRU consumer
or application nodes and supported by the PRU remoteproc driver.
These are used to configure the PRU hardware for specific user
applications.

The application nodes themselves should define their own bindings.

Co-developed-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
V3->V4:
* Addressed Rob's comments regarding max and min Items.
* removed the dependencies tag as it was redundant.
---
.../bindings/remoteproc/ti,pru-consumer.yaml  | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml

diff --git a/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
new file mode 100644
index 000000000000..df384b44259b
--- /dev/null
+++ b/Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/remoteproc/ti,pru-consumer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common TI PRU Consumer Binding
+
+maintainers:
+  - Suman Anna <s-anna@ti.com>
+
+description: |
+  A PRU application/consumer/user node typically uses one or more PRU device
+  nodes to implement a PRU application/functionality. Each application/client
+  node would need a reference to at least a PRU node, and optionally define
+  some properties needed for hardware/firmware configuration. The below
+  properties are a list of common properties supported by the PRU remoteproc
+  infrastructure.
+
+  The application nodes shall define their own bindings like regular platform
+  devices, so below are in addition to each node's bindings.
+
+properties:
+  ti,prus:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    description: phandles to the PRU, RTU or Tx_PRU nodes used
+    minItems: 1
+    maxItems: 6
+    items:
+      maxItems: 1
+
+  firmware-name:
+    $ref: /schemas/types.yaml#/definitions/string-array
+    minItems: 1
+    maxItems: 6
+    description: |
+      firmwares for the PRU cores, the default firmware for the core from
+      the PRU node will be used if not provided. The firmware names should
+      correspond to the PRU cores listed in the 'ti,prus' property
+
+  ti,pruss-gp-mux-sel:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 1
+    maxItems: 6
+    items:
+      enum: [0, 1, 2, 3, 4]
+    description: |
+      array of values for the GP_MUX_SEL under PRUSS_GPCFG register for a PRU.
+      This selects the internal muxing scheme for the PRU instance. Values
+      should correspond to the PRU cores listed in the 'ti,prus' property. The
+      GP_MUX_SEL setting is a per-slice setting (one setting for PRU0, RTU0,
+      and Tx_PRU0 on K3 SoCs). Use the same value for all cores within the
+      same slice in the associative array. If the array size is smaller than
+      the size of 'ti,prus' property, the default out-of-reset value (0) for the
+      PRU core is used.
+
+required:
+  - ti,prus
+
+additionalProperties: true
+
+examples:
+  - |
+    /* PRU application node example */
+    pru-app {
+        ti,prus = <&pru0>, <&pru1>;
+        firmware-name = "pruss-app-fw0", "pruss-app-fw1";
+        ti,pruss-gp-mux-sel = <2>, <1>;
+    };
-- 
2.17.1

Re: [PATCH v4 1/6] dt-bindings: remoteproc: Add PRU consumer bindings

[Rob Herring]

On Fri, 03 Jun 2022 17:45:15 +0530, Puranjay Mohan wrote:
> From: Suman Anna <s-anna@ti.com>
> 
> Add a YAML binding document for PRU consumers. The binding includes
> all the common properties that can be used by different PRU consumer
> or application nodes and supported by the PRU remoteproc driver.
> These are used to configure the PRU hardware for specific user
> applications.
> 
> The application nodes themselves should define their own bindings.
> 
> Co-developed-by: Tero Kristo <t-kristo@ti.com>
> Signed-off-by: Tero Kristo <t-kristo@ti.com>
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
> Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
> ---
> V3->V4:
> * Addressed Rob's comments regarding max and min Items.
> * removed the dependencies tag as it was redundant.
> ---
> .../bindings/remoteproc/ti,pru-consumer.yaml  | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH v4 2/6] remoteproc: pru: Add APIs to get and put the PRU cores

[Puranjay Mohan]

From: Tero Kristo <t-kristo@ti.com>

Add two new APIs, pru_rproc_get() and pru_rproc_put(), to the PRU
driver to 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.

The pru_rproc_get() function returns the rproc handle corresponding
to a PRU core identified by the device tree "ti,prus" property under
the client node. The pru_rproc_put() is the complementary function
to pru_rproc_get().

Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Co-developed-by: Puranjay Mohan <p-mohan@ti.com>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 138 +++++++++++++++++++++++++++++++--
 include/linux/pruss.h          |  56 +++++++++++++
 2 files changed, 189 insertions(+), 5 deletions(-)
 create mode 100644 include/linux/pruss.h

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 1777a01fa84e..7a35b400287a 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -2,12 +2,13 @@
 /*
  * PRU-ICSS remoteproc driver for various TI SoCs
  *
- * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
+ * Copyright (C) 2014-2022 Texas Instruments Incorporated - https://www.ti.com/
  *
  * Author(s):
  *	Suman Anna <s-anna@ti.com>
  *	Andrew F. Davis <afd@ti.com>
  *	Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> for Texas Instruments
+ *	Puranjay Mohan <p-mohan@ti.com>
  */
 
 #include <linux/bitops.h>
@@ -16,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
+#include <linux/pruss.h>
 #include <linux/pruss_driver.h>
 #include <linux/remoteproc.h>
 
@@ -111,6 +113,8 @@ struct pru_private_data {
  * @rproc: remoteproc pointer for this PRU core
  * @data: PRU core specific data
  * @mem_regions: data for each of the PRU memory regions
+ * @client_np: client device node
+ * @lock: mutex to protect client usage
  * @fw_name: name of firmware image used during loading
  * @mapped_irq: virtual interrupt numbers of created fw specific mapping
  * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
@@ -126,6 +130,8 @@ struct pru_rproc {
 	struct rproc *rproc;
 	const struct pru_private_data *data;
 	struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
+	struct device_node *client_np;
+	struct mutex lock; /* client access lock */
 	const char *fw_name;
 	unsigned int *mapped_irq;
 	struct pru_irq_rsc *pru_interrupt_map;
@@ -146,6 +152,125 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
 	writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
 }
 
+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, "ti,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 || !(&pdev->dev) || !((&pdev->dev)->driver))
+		/* probably PRU not yet probed */
+		return ERR_PTR(-EPROBE_DEFER);
+
+	/* make sure it is PRU rproc */
+	if (!is_pru_rproc(&pdev->dev)) {
+		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 ti,prus property
+ * @pru_id: optional pointer to return the PRU remoteproc processor id
+ *
+ * This function looks through a client device node's "ti,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.
+ *
+ * When optional @pru_id pointer is passed the PRU remoteproc processor id is
+ * returned.
+ *
+ * Return: 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,
+			    enum pruss_pru_id *pru_id)
+{
+	struct rproc *rproc;
+	struct pru_rproc *pru;
+	struct device *dev;
+
+	try_module_get(THIS_MODULE);
+
+	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(dev);
+		return ERR_PTR(-EBUSY);
+	}
+
+	pru->client_np = np;
+
+	mutex_unlock(&pru->lock);
+
+	if (pru_id)
+		*pru_id = pru->id;
+
+	return rproc;
+}
+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) || !is_pru_rproc(rproc->dev.parent))
+		return;
+
+	pru = rproc->priv;
+
+	mutex_lock(&pru->lock);
+
+	if (!pru->client_np) {
+		mutex_unlock(&pru->lock);
+		return;
+	}
+
+	pru->client_np = NULL;
+	mutex_unlock(&pru->lock);
+
+	put_device(&rproc->dev);
+}
+EXPORT_SYMBOL_GPL(pru_rproc_put);
+
 static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
 {
 	return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -438,7 +563,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
 	dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
 	dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
 	/* PRU1 has its local RAM addresses reversed */
-	if (pru->id == 1)
+	if (pru->id == PRUSS_PRU1)
 		swap(dram0, dram1);
 	shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
 
@@ -747,14 +872,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
 	case RTU0_IRAM_ADDR_MASK:
 		fallthrough;
 	case PRU0_IRAM_ADDR_MASK:
-		pru->id = 0;
+		pru->id = PRUSS_PRU0;
 		break;
 	case TX_PRU1_IRAM_ADDR_MASK:
 		fallthrough;
 	case RTU1_IRAM_ADDR_MASK:
 		fallthrough;
 	case PRU1_IRAM_ADDR_MASK:
-		pru->id = 1;
+		pru->id = PRUSS_PRU1;
 		break;
 	default:
 		ret = -EINVAL;
@@ -816,6 +941,8 @@ static int pru_rproc_probe(struct platform_device *pdev)
 	pru->pruss = platform_get_drvdata(ppdev);
 	pru->rproc = rproc;
 	pru->fw_name = fw_name;
+	pru->client_np = NULL;
+	mutex_init(&pru->lock);
 
 	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
 		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
@@ -903,7 +1030,7 @@ MODULE_DEVICE_TABLE(of, pru_rproc_match);
 
 static struct platform_driver pru_rproc_driver = {
 	.driver = {
-		.name   = "pru-rproc",
+		.name   = PRU_RPROC_DRVNAME,
 		.of_match_table = pru_rproc_match,
 		.suppress_bind_attrs = true,
 	},
@@ -915,5 +1042,6 @@ module_platform_driver(pru_rproc_driver);
 MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
 MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>");
+MODULE_AUTHOR("Puranjay Mohan <p-mohan@ti.com>");
 MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
 MODULE_LICENSE("GPL v2");
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
new file mode 100644
index 000000000000..fdc719b43db0
--- /dev/null
+++ b/include/linux/pruss.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/**
+ * PRU-ICSS Subsystem user interfaces
+ *
+ * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
+ *	Suman Anna <s-anna@ti.com>
+ */
+
+#ifndef __LINUX_PRUSS_H
+#define __LINUX_PRUSS_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+
+#define PRU_RPROC_DRVNAME "pru-rproc"
+
+/*
+ * enum pruss_pru_id - PRU core identifiers
+ */
+enum pruss_pru_id {
+	PRUSS_PRU0 = 0,
+	PRUSS_PRU1,
+	PRUSS_NUM_PRUS,
+};
+
+struct device_node;
+
+#if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
+
+struct rproc *pru_rproc_get(struct device_node *np, int index,
+			    enum pruss_pru_id *pru_id);
+void pru_rproc_put(struct rproc *rproc);
+
+#else
+
+static inline struct rproc *
+pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline void pru_rproc_put(struct rproc *rproc) { }
+
+#endif /* CONFIG_PRU_REMOTEPROC */
+
+static inline bool is_pru_rproc(struct device *dev)
+{
+	const char *drv_name = dev_driver_string(dev);
+
+	if (strncmp(drv_name, PRU_RPROC_DRVNAME, sizeof(PRU_RPROC_DRVNAME)))
+		return false;
+
+	return true;
+}
+
+#endif /* __LINUX_PRUSS_H */
-- 
2.17.1

[PATCH v4 3/6] remoteproc: pru: Make sysfs entries read-only for PRU client driven boots

[Puranjay Mohan]

From: Suman Anna <s-anna@ti.com>

The PRU remoteproc driver is not configured for 'auto-boot' by default,
and allows to be booted either by in-kernel PRU client drivers or by
userspace using the generic remoteproc sysfs interfaces. The sysfs
interfaces should not be permitted to change the remoteproc firmwares
or states when a PRU is being managed by an in-kernel client driver.
Use the newly introduced remoteproc generic 'sysfs_read_only' flag to
provide these restrictions by setting and clearing it appropriately
during the PRU acquire and release steps.

Signed-off-by: Suman Anna <s-anna@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 7a35b400287a..9fed3e0372d3 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -231,6 +231,7 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	}
 
 	pru->client_np = np;
+	rproc->sysfs_read_only = true;
 
 	mutex_unlock(&pru->lock);
 
@@ -265,6 +266,7 @@ void pru_rproc_put(struct rproc *rproc)
 	}
 
 	pru->client_np = NULL;
+	rproc->sysfs_read_only = false;
 	mutex_unlock(&pru->lock);
 
 	put_device(&rproc->dev);
-- 
2.17.1

[PATCH v4 4/6] remoteproc: pru: Add pru_rproc_set_ctable() function

[Puranjay Mohan]

From: Roger Quadros <rogerq@ti.com>

Some firmwares expect the OS drivers to configure the CTABLE
entries publishing dynamically allocated memory regions. For
example, the PRU Ethernet firmwares use the C28 and C30 entries
for retrieving the Shared RAM and System SRAM (OCMC) areas
allocated by the PRU Ethernet client driver.

Provide a way for users to do that through a new API,
pru_rproc_set_ctable(). The API returns 0 on success and
a negative value on error.

NOTE:
The programmable CTABLE entries are typically re-programmed by
the PRU firmwares when dealing with a certain block of memory
during block processing. This API provides an interface to the
PRU client drivers to publish a dynamically allocated memory
block with the PRU firmware using a CTABLE entry instead of a
negotiated address in shared memory. Additional synchronization
may be needed between the PRU client drivers and firmwares if
different addresses needs to be published at run-time reusing
the same CTABLE entry.

Co-developed-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 59 ++++++++++++++++++++++++++++++++++
 include/linux/pruss.h          | 22 +++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 9fed3e0372d3..d06b763e995e 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -119,6 +119,7 @@ struct pru_private_data {
  * @mapped_irq: virtual interrupt numbers of created fw specific mapping
  * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
  * @pru_interrupt_map_sz: pru_interrupt_map size
+ * @rmw_lock: lock for read, modify, write operations on registers
  * @dbg_single_step: debug state variable to set PRU into single step mode
  * @dbg_continuous: debug state variable to restore PRU execution mode
  * @evt_count: number of mapped events
@@ -136,6 +137,7 @@ struct pru_rproc {
 	unsigned int *mapped_irq;
 	struct pru_irq_rsc *pru_interrupt_map;
 	size_t pru_interrupt_map_sz;
+	spinlock_t rmw_lock; /* register access lock */
 	u32 dbg_single_step;
 	u32 dbg_continuous;
 	u8 evt_count;
@@ -152,6 +154,23 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
 	writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
 }
 
+static inline
+void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
+			 u32 mask, u32 set)
+{
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pru->rmw_lock, flags);
+
+	val = pru_control_read_reg(pru, reg);
+	val &= ~mask;
+	val |= (set & mask);
+	pru_control_write_reg(pru, reg, val);
+
+	spin_unlock_irqrestore(&pru->rmw_lock, flags);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
 	struct device_node *rproc_np = NULL;
@@ -273,6 +292,45 @@ void pru_rproc_put(struct rproc *rproc)
 }
 EXPORT_SYMBOL_GPL(pru_rproc_put);
 
+/**
+ * pru_rproc_set_ctable() - set the constant table index for the PRU
+ * @rproc: the rproc instance of the PRU
+ * @c: constant table index to set
+ * @addr: physical address to set it to
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr)
+{
+	struct pru_rproc *pru = rproc->priv;
+	unsigned int reg;
+	u32 mask, set;
+	u16 idx;
+	u16 idx_mask;
+
+	if (IS_ERR_OR_NULL(rproc))
+		return -EINVAL;
+
+	if (!rproc->dev.parent || !is_pru_rproc(rproc->dev.parent))
+		return -ENODEV;
+
+	/* pointer is 16 bit and index is 8-bit so mask out the rest */
+	idx_mask = (c >= PRU_C28) ? 0xFFFF : 0xFF;
+
+	/* ctable uses bit 8 and upwards only */
+	idx = (addr >> 8) & idx_mask;
+
+	/* configurable ctable (i.e. C24) starts at PRU_CTRL_CTBIR0 */
+	reg = PRU_CTRL_CTBIR0 + 4 * (c >> 1);
+	mask = idx_mask << (16 * (c & 1));
+	set = idx << (16 * (c & 1));
+
+	pru_control_set_reg(pru, reg, mask, set);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pru_rproc_set_ctable);
+
 static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
 {
 	return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
@@ -944,6 +1002,7 @@ static int pru_rproc_probe(struct platform_device *pdev)
 	pru->rproc = rproc;
 	pru->fw_name = fw_name;
 	pru->client_np = NULL;
+	spin_lock_init(&pru->rmw_lock);
 	mutex_init(&pru->lock);
 
 	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index fdc719b43db0..d830e20056c7 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -23,13 +23,29 @@ enum pruss_pru_id {
 	PRUSS_NUM_PRUS,
 };
 
+/*
+ * enum pru_ctable_idx - Configurable Constant table index identifiers
+ */
+enum pru_ctable_idx {
+	PRU_C24 = 0,
+	PRU_C25,
+	PRU_C26,
+	PRU_C27,
+	PRU_C28,
+	PRU_C29,
+	PRU_C30,
+	PRU_C31,
+};
+
 struct device_node;
+struct rproc;
 
 #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
 
 struct rproc *pru_rproc_get(struct device_node *np, int index,
 			    enum pruss_pru_id *pru_id);
 void pru_rproc_put(struct rproc *rproc);
+int pru_rproc_set_ctable(struct rproc *rproc, enum pru_ctable_idx c, u32 addr);
 
 #else
 
@@ -41,6 +57,12 @@ pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
 
 static inline void pru_rproc_put(struct rproc *rproc) { }
 
+static inline int pru_rproc_set_ctable(struct rproc *rproc,
+				       enum pru_ctable_idx c, u32 addr)
+{
+	return -EOPNOTSUPP;
+}
+
 #endif /* CONFIG_PRU_REMOTEPROC */
 
 static inline bool is_pru_rproc(struct device *dev)
-- 
2.17.1

[PATCH v4 5/6] remoteproc: pru: Configure firmware based on client setup

[Puranjay Mohan]

From: Tero Kristo <t-kristo@ti.com>

Client device node property firmware-name is now used to configure
firmware for the PRU instances. The default firmware is also
restored once releasing the PRU resource.

Co-developed-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 35 ++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index d06b763e995e..2977eb50631b 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -171,6 +171,23 @@ void pru_control_set_reg(struct pru_rproc *pru, unsigned int reg,
 	spin_unlock_irqrestore(&pru->rmw_lock, flags);
 }
 
+/**
+ * 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
+ *
+ * Return: 0 on success, or errno in error case.
+ */
+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);
+}
+
 static struct rproc *__pru_rproc_get(struct device_node *np, int index)
 {
 	struct device_node *rproc_np = NULL;
@@ -231,6 +248,8 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	struct rproc *rproc;
 	struct pru_rproc *pru;
 	struct device *dev;
+	const char *fw_name;
+	int ret;
 
 	try_module_get(THIS_MODULE);
 
@@ -257,7 +276,21 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	if (pru_id)
 		*pru_id = pru->id;
 
+	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;
+		}
+	}
+
 	return rproc;
+
+err:
+	pru_rproc_put(rproc);
+	return ERR_PTR(ret);
 }
 EXPORT_SYMBOL_GPL(pru_rproc_get);
 
@@ -277,6 +310,8 @@ void pru_rproc_put(struct rproc *rproc)
 
 	pru = rproc->priv;
 
+	pru_rproc_set_firmware(rproc, NULL);
+
 	mutex_lock(&pru->lock);
 
 	if (!pru->client_np) {
-- 
2.17.1

[PATCH v4 6/6] remoteproc: pru: add support for configuring GPMUX based on client setup

[Puranjay Mohan]

From: Tero Kristo <t-kristo@ti.com>

Client device node property ti,pruss-gp-mux-sel can now be used to
configure the GPMUX config value for PRU.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
[s-anna@ti.com: simplify the pru id usage]
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Puranjay Mohan <p-mohan@ti.com>
---
 drivers/remoteproc/pru_rproc.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
index 2977eb50631b..b532069fe259 100644
--- a/drivers/remoteproc/pru_rproc.c
+++ b/drivers/remoteproc/pru_rproc.c
@@ -123,6 +123,7 @@ struct pru_private_data {
  * @dbg_single_step: debug state variable to set PRU into single step mode
  * @dbg_continuous: debug state variable to restore PRU execution mode
  * @evt_count: number of mapped events
+ * @gpmux_save: saved value for gpmux config
  */
 struct pru_rproc {
 	int id;
@@ -141,6 +142,7 @@ struct pru_rproc {
 	u32 dbg_single_step;
 	u32 dbg_continuous;
 	u8 evt_count;
+	u8 gpmux_save;
 };
 
 static inline u32 pru_control_read_reg(struct pru_rproc *pru, unsigned int reg)
@@ -250,6 +252,7 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 	struct device *dev;
 	const char *fw_name;
 	int ret;
+	u32 mux;
 
 	try_module_get(THIS_MODULE);
 
@@ -273,6 +276,22 @@ struct rproc *pru_rproc_get(struct device_node *np, int index,
 
 	mutex_unlock(&pru->lock);
 
+	ret = pruss_cfg_get_gpmux(pru->pruss, pru->id, &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 = pruss_cfg_set_gpmux(pru->pruss, pru->id, mux);
+                if (ret) {
+                        dev_err(dev, "failed to set cfg gpmux: %d\n", ret);
+                        goto err;
+                }
+        }
+
 	if (pru_id)
 		*pru_id = pru->id;
 
@@ -310,6 +329,7 @@ void pru_rproc_put(struct rproc *rproc)
 
 	pru = rproc->priv;
 
+	pruss_cfg_set_gpmux(pru->pruss, pru->id, pru->gpmux_save);
 	pru_rproc_set_firmware(rproc, NULL);
 
 	mutex_lock(&pru->lock);
-- 
2.17.1

Re: [PATCH v4 0/6] Introduce PRU remoteproc consumer API

[Mathieu Poirier]

I have started to review this set, comments will come over the next few days.  I
will clearly inform you when I am done reviewing.

Thanks,
Mathieu

On Fri, Jun 03, 2022 at 05:45:14PM +0530, Puranjay Mohan wrote:
> This is the v4 of the patch series [1]. The v3 had some comments
> on the DT patch that have been addressed here. The 6th patch in this
> series was missed in the previous versions, so, it has been added now.
> 
> I have posted two more patch series that depend on this series, one to
> the soc tree and another to the networking tree. I had sent all the 3
> series, including this one as RFC [2] to get comments and to explain the
> dependencies.
> 
> The Programmable Real-Time Unit and Industrial Communication Subsystem
> (PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
> RISC cores (Programmable Real-Time Units, or PRUs) for program execution.
> 
> There are 3 foundation components for PRUSS subsystem: the PRUSS platform
> driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
> already merged and can be found under:
> 1) drivers/soc/ti/pruss.c
>    Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
> 2) drivers/irqchip/irq-pruss-intc.c
>    Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
> 3) drivers/remoteproc/pru_rproc.c
>    Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml
> 
> The programmable nature of the PRUs provide flexibility to implement custom
> peripheral interfaces, fast real-time responses, or specialized data handling.
> Example of a PRU consumer drivers will be:
>   - Software UART over PRUSS
>   - PRU-ICSS Ethernet EMAC
> 
> In order to make usage of common PRU resources and allow the consumer drivers to
> configure the PRU hardware for specific usage the PRU API is introduced.
> 
> [1] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220418104118.12878-1-p-mohan@ti.com/
> [2] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220406094358.7895-1-p-mohan@ti.com/
> 
> Thanks and Regards,
> Puranjay Mohan
> 
> Roger Quadros (1):
>   remoteproc: pru: Add pru_rproc_set_ctable() function
> 
> Suman Anna (2):
>   dt-bindings: remoteproc: Add PRU consumer bindings
>   remoteproc: pru: Make sysfs entries read-only for PRU client driven
>     boots
> 
> Tero Kristo (3):
>   remoteproc: pru: Add APIs to get and put the PRU cores
>   remoteproc: pru: Configure firmware based on client setup
>   remoteproc: pru: add support for configuring GPMUX based on client
>     setup
> 
>  .../bindings/remoteproc/ti,pru-consumer.yaml  |  69 +++++
>  drivers/remoteproc/pru_rproc.c                | 254 +++++++++++++++++-
>  include/linux/pruss.h                         |  78 ++++++
>  3 files changed, 396 insertions(+), 5 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
>  create mode 100644 include/linux/pruss.h
> 
> -- 
> 2.17.1
> 

Re: [PATCH v4 0/6] Introduce PRU remoteproc consumer API

[Mathieu Poirier]

On Mon, Jun 06, 2022 at 09:56:12AM -0600, Mathieu Poirier wrote:
> I have started to review this set, comments will come over the next few days.  I
> will clearly inform you when I am done reviewing.

This patch is giving me several checkpatch warnings that should have been caught
before sending the patches out to the mailing list.  As such I will not review
this work and seriously considering adding your next revision at the very bottom
of my queue.

> 
> Thanks,
> Mathieu
> 
> On Fri, Jun 03, 2022 at 05:45:14PM +0530, Puranjay Mohan wrote:
> > This is the v4 of the patch series [1]. The v3 had some comments
> > on the DT patch that have been addressed here. The 6th patch in this
> > series was missed in the previous versions, so, it has been added now.
> > 
> > I have posted two more patch series that depend on this series, one to
> > the soc tree and another to the networking tree. I had sent all the 3
> > series, including this one as RFC [2] to get comments and to explain the
> > dependencies.
> > 
> > The Programmable Real-Time Unit and Industrial Communication Subsystem
> > (PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
> > RISC cores (Programmable Real-Time Units, or PRUs) for program execution.
> > 
> > There are 3 foundation components for PRUSS subsystem: the PRUSS platform
> > driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
> > already merged and can be found under:
> > 1) drivers/soc/ti/pruss.c
> >    Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
> > 2) drivers/irqchip/irq-pruss-intc.c
> >    Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
> > 3) drivers/remoteproc/pru_rproc.c
> >    Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml
> > 
> > The programmable nature of the PRUs provide flexibility to implement custom
> > peripheral interfaces, fast real-time responses, or specialized data handling.
> > Example of a PRU consumer drivers will be:
> >   - Software UART over PRUSS
> >   - PRU-ICSS Ethernet EMAC
> > 
> > In order to make usage of common PRU resources and allow the consumer drivers to
> > configure the PRU hardware for specific usage the PRU API is introduced.
> > 
> > [1] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220418104118.12878-1-p-mohan@ti.com/
> > [2] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220406094358.7895-1-p-mohan@ti.com/
> > 
> > Thanks and Regards,
> > Puranjay Mohan
> > 
> > Roger Quadros (1):
> >   remoteproc: pru: Add pru_rproc_set_ctable() function
> > 
> > Suman Anna (2):
> >   dt-bindings: remoteproc: Add PRU consumer bindings
> >   remoteproc: pru: Make sysfs entries read-only for PRU client driven
> >     boots
> > 
> > Tero Kristo (3):
> >   remoteproc: pru: Add APIs to get and put the PRU cores
> >   remoteproc: pru: Configure firmware based on client setup
> >   remoteproc: pru: add support for configuring GPMUX based on client
> >     setup
> > 
> >  .../bindings/remoteproc/ti,pru-consumer.yaml  |  69 +++++
> >  drivers/remoteproc/pru_rproc.c                | 254 +++++++++++++++++-
> >  include/linux/pruss.h                         |  78 ++++++
> >  3 files changed, 396 insertions(+), 5 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
> >  create mode 100644 include/linux/pruss.h
> > 
> > -- 
> > 2.17.1
> > 

Re: [PATCH v4 0/6] Introduce PRU remoteproc consumer API

[Puranjay Mohan]

Hi Mathieu,

On 06/06/22 21:45, Mathieu Poirier wrote:
> On Mon, Jun 06, 2022 at 09:56:12AM -0600, Mathieu Poirier wrote:
>> I have started to review this set, comments will come over the next few days.  I
>> will clearly inform you when I am done reviewing.
> 
> This patch is giving me several checkpatch warnings that should have been caught
> before sending the patches out to the mailing list.  As such I will not review
> this work and seriously considering adding your next revision at the very bottom
> of my queue.

I am sorry for this. I had introduced the 6th patch in v4 and it is
giving these errors. I have fixed them and sent a v5. Please don't move
the v5 to the bottom of the queue. I will be extra cautious from next time.

Thanks,
Puranjay Mohan

> 
>>
>> Thanks,
>> Mathieu
>>
>> On Fri, Jun 03, 2022 at 05:45:14PM +0530, Puranjay Mohan wrote:
>>> This is the v4 of the patch series [1]. The v3 had some comments
>>> on the DT patch that have been addressed here. The 6th patch in this
>>> series was missed in the previous versions, so, it has been added now.
>>>
>>> I have posted two more patch series that depend on this series, one to
>>> the soc tree and another to the networking tree. I had sent all the 3
>>> series, including this one as RFC [2] to get comments and to explain the
>>> dependencies.
>>>
>>> The Programmable Real-Time Unit and Industrial Communication Subsystem
>>> (PRU-ICSS or simply PRUSS) on various TI SoCs consists of dual 32-bit
>>> RISC cores (Programmable Real-Time Units, or PRUs) for program execution.
>>>
>>> There are 3 foundation components for PRUSS subsystem: the PRUSS platform
>>> driver, the PRUSS INTC driver and the PRUSS remoteproc driver. All were
>>> already merged and can be found under:
>>> 1) drivers/soc/ti/pruss.c
>>>    Documentation/devicetree/bindings/soc/ti/ti,pruss.yaml
>>> 2) drivers/irqchip/irq-pruss-intc.c
>>>    Documentation/devicetree/bindings/interrupt-controller/ti,pruss-intc.yaml
>>> 3) drivers/remoteproc/pru_rproc.c
>>>    Documentation/devicetree/bindings/remoteproc/ti,pru-rproc.yaml
>>>
>>> The programmable nature of the PRUs provide flexibility to implement custom
>>> peripheral interfaces, fast real-time responses, or specialized data handling.
>>> Example of a PRU consumer drivers will be:
>>>   - Software UART over PRUSS
>>>   - PRU-ICSS Ethernet EMAC
>>>
>>> In order to make usage of common PRU resources and allow the consumer drivers to
>>> configure the PRU hardware for specific usage the PRU API is introduced.
>>>
>>> [1] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220418104118.12878-1-p-mohan@ti.com/
>>> [2] https://patchwork.kernel.org/project/linux-remoteproc/cover/20220406094358.7895-1-p-mohan@ti.com/
>>>
>>> Thanks and Regards,
>>> Puranjay Mohan
>>>
>>> Roger Quadros (1):
>>>   remoteproc: pru: Add pru_rproc_set_ctable() function
>>>
>>> Suman Anna (2):
>>>   dt-bindings: remoteproc: Add PRU consumer bindings
>>>   remoteproc: pru: Make sysfs entries read-only for PRU client driven
>>>     boots
>>>
>>> Tero Kristo (3):
>>>   remoteproc: pru: Add APIs to get and put the PRU cores
>>>   remoteproc: pru: Configure firmware based on client setup
>>>   remoteproc: pru: add support for configuring GPMUX based on client
>>>     setup
>>>
>>>  .../bindings/remoteproc/ti,pru-consumer.yaml  |  69 +++++
>>>  drivers/remoteproc/pru_rproc.c                | 254 +++++++++++++++++-
>>>  include/linux/pruss.h                         |  78 ++++++
>>>  3 files changed, 396 insertions(+), 5 deletions(-)
>>>  create mode 100644 Documentation/devicetree/bindings/remoteproc/ti,pru-consumer.yaml
>>>  create mode 100644 include/linux/pruss.h
>>>
>>> -- 
>>> 2.17.1
>>>