[PATCH v6 0/8] RZN1 DMA support

[PATCH v6 0/8] RZN1 DMA support

[Miquel Raynal]

Hello,

Here is a first series bringing DMA support to RZN1 platforms. Soon a
second series will come with changes made to the UART controller
driver, in order to interact with the RZN1 DMA controller.

Stephen acked the sysctrl patch (in the clk driver) but somehow I feel
like it would be good to have this patch applied on both sides
(dmaengine and clk) because more changes will depend on the addition of
this helper, that are not related to DMA at all. I'll let you folks
figure out what is best.

Cheers,
Miquèl

Changes in v6:
* Added Stephen's acks.
* Fixed an extra newline added in the middle of nowhere.
* Rebased on top of v5.18-rc1.

Changes in v5:
* Used gotos in rzn1_dmamux_route_allocate().
* Changed the prefix to "dmaengine:".
* Dropped the partial transfers fix.
* Added Rob's acks.

Changes in v4:
* Freed "map" in the error path of the dmamux driver.
* Improved a bit the style as requested by Prabhakar.
* Dropped a __maybe_unused.
* Reorder the includes.
* Added a dependency on ARCH_RZN1.
* Added Rob's Ack.
* Added a reg property to the dmamux binding file.
* Referenced the dmamux binding from the system controller file.
* Called of_platform_populate from the end of the system controller
  (clock) driver probe in order to probe the dmamux if it was
  populated.
* Added DMA properties to all the relevant UARTs.

Changes in v3:
* Added Reviewed-by tags.
* Exported the set_dmamux* symbol properly.
* Dropped a useless check in the probe and moved the sysctrl_priv
  assignation to the end of the probe.
* Renamed the dmamux driver
* Added a couple of missing MODULE_ macros in the dmamux driver.
* Decided to use a regular platform init call instead of the
  arch_initcall() initially proposed.
* s/%d/%u/ in printk's when appropriate.
* Used a hardcoded value instead of dmamux->dmac_requests when
  appropriate.
* Changed the variable name "master" to "dmac_idx" to be more
  descriptive.
* Dropped most of the of_* calls in favor of #define's.
* Fixed a typo.
* Exported two symbols from 8250_dma.c.

Changes in v2:
* Clarified that the 'fix' regarding non aligned reads would only apply
  to the DEV_TO_MEM case.
* Fix the DMA controller compatible string (copy-paste error).
* s/syscon/sysctrl/ as advised by Geert.
* Disabled irqs when taking the spinlock from the clocks driver.
* Moved the DMAMUX offset inside the driver.
* Removed extra commas.
* Improved the style as suggested by Andy.
* Removed a dupplicated check against the device node presence.
* Reduced the number of lines of code by using dev_err_probe().
* Created a Kconfig symbol for DMAMUX to fix the two robot reports
  received and be sure there was no useless overhead with other
  platforms.
* Exported the serial8250_{tx,rx}_dma() symbols.

Miquel Raynal (8):
  dt-bindings: dmaengine: Introduce RZN1 dmamux bindings
  dt-bindings: clock: r9a06g032-sysctrl: Reference the DMAMUX subnode
  dt-bindings: dmaengine: Introduce RZN1 DMA compatible
  soc: renesas: rzn1-sysc: Export function to set dmamux
  dmaengine: dw: dmamux: Introduce RZN1 DMA router support
  dmaengine: dw: Add RZN1 compatible
  ARM: dts: r9a06g032: Add the two DMA nodes
  ARM: dts: r9a06g032: Describe the DMA router

 .../clock/renesas,r9a06g032-sysctrl.yaml      |  11 ++
 .../bindings/dma/renesas,rzn1-dmamux.yaml     |  51 ++++++
 .../bindings/dma/snps,dma-spear1340.yaml      |   8 +-
 MAINTAINERS                                   |   1 +
 arch/arm/boot/dts/r9a06g032.dtsi              |  40 +++++
 drivers/clk/renesas/r9a06g032-clocks.c        |  36 +++-
 drivers/dma/dw/Kconfig                        |   9 +
 drivers/dma/dw/Makefile                       |   2 +
 drivers/dma/dw/platform.c                     |   1 +
 drivers/dma/dw/rzn1-dmamux.c                  | 157 ++++++++++++++++++
 include/linux/soc/renesas/r9a06g032-sysctrl.h |  11 ++
 11 files changed, 325 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
 create mode 100644 drivers/dma/dw/rzn1-dmamux.c
 create mode 100644 include/linux/soc/renesas/r9a06g032-sysctrl.h

-- 
2.27.0

[PATCH v6 1/8] dt-bindings: dmaengine: Introduce RZN1 dmamux bindings

[Miquel Raynal]

The Renesas RZN1 DMA IP is based on a DW core, with eg. an additional
dmamux register located in the system control area which can take up to
32 requests (16 per DMA controller). Each DMA channel can be wired to
two different peripherals.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/dma/renesas,rzn1-dmamux.yaml     | 51 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 52 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml

diff --git a/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml b/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
new file mode 100644
index 000000000000..d83013b0dd74
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/dma/renesas,rzn1-dmamux.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/N1 DMA mux
+
+maintainers:
+  - Miquel Raynal <miquel.raynal@bootlin.com>
+
+allOf:
+  - $ref: "dma-router.yaml#"
+
+properties:
+  compatible:
+    const: renesas,rzn1-dmamux
+
+  reg:
+    maxItems: 1
+    description: DMA mux first register offset within the system control parent.
+
+  '#dma-cells':
+    const: 6
+    description:
+      The first four cells are dedicated to the master DMA controller. The fifth
+      cell gives the DMA mux bit index that must be set starting from 0. The
+      sixth cell gives the binary value that must be written there, ie. 0 or 1.
+
+  dma-masters:
+    minItems: 1
+    maxItems: 2
+
+  dma-requests:
+    const: 32
+
+required:
+  - reg
+  - dma-requests
+
+additionalProperties: false
+
+examples:
+  - |
+    dma-router@a0 {
+      compatible = "renesas,rzn1-dmamux";
+      reg = <0xa0 4>;
+      #dma-cells = <6>;
+      dma-masters = <&dma0 &dma1>;
+      dma-requests = <32>;
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index fd768d43e048..120d3ae57a4b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19040,6 +19040,7 @@ SYNOPSYS DESIGNWARE DMAC DRIVER
 M:	Viresh Kumar <vireshk@kernel.org>
 R:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
 S:	Maintained
+F:	Documentation/devicetree/bindings/dma/renesas,rzn1-dmamux.yaml
 F:	Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml
 F:	drivers/dma/dw/
 F:	include/dt-bindings/dma/dw-dmac.h
-- 
2.27.0

[PATCH v6 2/8] dt-bindings: clock: r9a06g032-sysctrl: Reference the DMAMUX subnode

[Miquel Raynal]

This system controller contains several registers that have nothing to
do with the clock handling, like the DMA mux register. Describe this
part of the system controller as a subnode.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/clock/renesas,r9a06g032-sysctrl.yaml     | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/renesas,r9a06g032-sysctrl.yaml b/Documentation/devicetree/bindings/clock/renesas,r9a06g032-sysctrl.yaml
index 25dbb0fac065..95bf485c6cec 100644
--- a/Documentation/devicetree/bindings/clock/renesas,r9a06g032-sysctrl.yaml
+++ b/Documentation/devicetree/bindings/clock/renesas,r9a06g032-sysctrl.yaml
@@ -39,6 +39,17 @@ properties:
   '#power-domain-cells':
     const: 0
 
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 1
+
+patternProperties:
+  "^dma-router@[a-f0-9]+$":
+    type: object
+    $ref: "../dma/renesas,rzn1-dmamux.yaml#"
+
 required:
   - compatible
   - reg
-- 
2.27.0

[PATCH v6 3/8] dt-bindings: dmaengine: Introduce RZN1 DMA compatible

[Miquel Raynal]

Just like for the NAND controller that is also on this SoC, let's
provide a SoC generic and a more specific couple of compatibles for the
DMA controller.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/dma/snps,dma-spear1340.yaml       | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml b/Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml
index 6b35089ac017..c13649bf7f19 100644
--- a/Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml
+++ b/Documentation/devicetree/bindings/dma/snps,dma-spear1340.yaml
@@ -15,7 +15,13 @@ allOf:
 
 properties:
   compatible:
-    const: snps,dma-spear1340
+    oneOf:
+      - const: snps,dma-spear1340
+      - items:
+          - enum:
+              - renesas,r9a06g032-dma
+          - const: renesas,rzn1-dma
+
 
   "#dma-cells":
     minimum: 3
-- 
2.27.0

[PATCH v6 4/8] soc: renesas: rzn1-sysc: Export function to set dmamux

[Miquel Raynal]

The dmamux register is located within the system controller.

Without syscon, we need an extra helper in order to give write access to
this register to a dmamux driver.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/clk/renesas/r9a06g032-clocks.c        | 35 ++++++++++++++++++-
 include/linux/soc/renesas/r9a06g032-sysctrl.h | 11 ++++++
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/soc/renesas/r9a06g032-sysctrl.h

diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
index c99942f0e4d4..052d99059981 100644
--- a/drivers/clk/renesas/r9a06g032-clocks.c
+++ b/drivers/clk/renesas/r9a06g032-clocks.c
@@ -20,9 +20,12 @@
 #include <linux/pm_clock.h>
 #include <linux/pm_domain.h>
 #include <linux/slab.h>
+#include <linux/soc/renesas/r9a06g032-sysctrl.h>
 #include <linux/spinlock.h>
 #include <dt-bindings/clock/r9a06g032-sysctrl.h>
 
+#define R9A06G032_SYSCTRL_DMAMUX 0xA0
+
 struct r9a06g032_gate {
 	u16 gate, reset, ready, midle,
 		scon, mirack, mistat;
@@ -315,6 +318,30 @@ struct r9a06g032_priv {
 	void __iomem *reg;
 };
 
+static struct r9a06g032_priv *sysctrl_priv;
+
+/* Exported helper to access the DMAMUX register */
+int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val)
+{
+	unsigned long flags;
+	u32 dmamux;
+
+	if (!sysctrl_priv)
+		return -EPROBE_DEFER;
+
+	spin_lock_irqsave(&sysctrl_priv->lock, flags);
+
+	dmamux = readl(sysctrl_priv->reg + R9A06G032_SYSCTRL_DMAMUX);
+	dmamux &= ~mask;
+	dmamux |= val & mask;
+	writel(dmamux, sysctrl_priv->reg + R9A06G032_SYSCTRL_DMAMUX);
+
+	spin_unlock_irqrestore(&sysctrl_priv->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(r9a06g032_sysctrl_set_dmamux);
+
 /* register/bit pairs are encoded as an uint16_t */
 static void
 clk_rdesc_set(struct r9a06g032_priv *clocks,
@@ -963,7 +990,13 @@ static int __init r9a06g032_clocks_probe(struct platform_device *pdev)
 	if (error)
 		return error;
 
-	return r9a06g032_add_clk_domain(dev);
+	error = r9a06g032_add_clk_domain(dev);
+	if (error)
+		return error;
+
+	sysctrl_priv = clocks;
+
+	return 0;
 }
 
 static const struct of_device_id r9a06g032_match[] = {
diff --git a/include/linux/soc/renesas/r9a06g032-sysctrl.h b/include/linux/soc/renesas/r9a06g032-sysctrl.h
new file mode 100644
index 000000000000..066dfb15cbdd
--- /dev/null
+++ b/include/linux/soc/renesas/r9a06g032-sysctrl.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__
+#define __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__
+
+#ifdef CONFIG_CLK_R9A06G032
+int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val);
+#else
+static inline int r9a06g032_sysctrl_set_dmamux(u32 mask, u32 val) { return -ENODEV; }
+#endif
+
+#endif /* __LINUX_SOC_RENESAS_R9A06G032_SYSCTRL_H__ */
-- 
2.27.0

[PATCH v6 5/8] dmaengine: dw: dmamux: Introduce RZN1 DMA router support

[Miquel Raynal]

The Renesas RZN1 DMA IP is based on a DW core, with eg. an additional
dmamux register located in the system control area which can take up to
32 requests (16 per DMA controller). Each DMA channel can be wired to
two different peripherals.

We need two additional information from the 'dmas' property: the channel
(bit in the dmamux register) that must be accessed and the value of the
mux for this channel.

Aside from the driver introduction, as these devices are described as
subnodes of the system controller, we also need the system controller
(clock) driver to populate its children manually. Starting from now on,
one child can be the dmamux.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/clk/renesas/r9a06g032-clocks.c |   3 +-
 drivers/dma/dw/Kconfig                 |   9 ++
 drivers/dma/dw/Makefile                |   2 +
 drivers/dma/dw/rzn1-dmamux.c           | 157 +++++++++++++++++++++++++
 4 files changed, 170 insertions(+), 1 deletion(-)
 create mode 100644 drivers/dma/dw/rzn1-dmamux.c

diff --git a/drivers/clk/renesas/r9a06g032-clocks.c b/drivers/clk/renesas/r9a06g032-clocks.c
index 052d99059981..1df56d7ab3e1 100644
--- a/drivers/clk/renesas/r9a06g032-clocks.c
+++ b/drivers/clk/renesas/r9a06g032-clocks.c
@@ -16,6 +16,7 @@
 #include <linux/math64.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/pm_clock.h>
 #include <linux/pm_domain.h>
@@ -996,7 +997,7 @@ static int __init r9a06g032_clocks_probe(struct platform_device *pdev)
 
 	sysctrl_priv = clocks;
 
-	return 0;
+	return of_platform_populate(np, NULL, NULL, dev);
 }
 
 static const struct of_device_id r9a06g032_match[] = {
diff --git a/drivers/dma/dw/Kconfig b/drivers/dma/dw/Kconfig
index db25f9b7778c..a9828ddd6d06 100644
--- a/drivers/dma/dw/Kconfig
+++ b/drivers/dma/dw/Kconfig
@@ -16,6 +16,15 @@ config DW_DMAC
 	  Support the Synopsys DesignWare AHB DMA controller. This
 	  can be integrated in chips such as the Intel Cherrytrail.
 
+config RZN1_DMAMUX
+	tristate "Renesas RZ/N1 DMAMUX driver"
+	depends on DW_DMAC
+	depends on ARCH_RZN1 || COMPILE_TEST
+	help
+	  Support the Renesas RZ/N1 DMAMUX which is located in front of
+	  the Synopsys DesignWare AHB DMA controller located on Renesas
+	  SoCs.
+
 config DW_DMAC_PCI
 	tristate "Synopsys DesignWare AHB DMA PCI driver"
 	depends on PCI
diff --git a/drivers/dma/dw/Makefile b/drivers/dma/dw/Makefile
index a6f358ad8591..8025f75e589c 100644
--- a/drivers/dma/dw/Makefile
+++ b/drivers/dma/dw/Makefile
@@ -7,5 +7,7 @@ obj-$(CONFIG_DW_DMAC)		+= dw_dmac.o
 dw_dmac-y			:= platform.o
 dw_dmac-$(CONFIG_OF)		+= of.o
 
+obj-$(CONFIG_RZN1_DMAMUX)	+= rzn1-dmamux.o
+
 obj-$(CONFIG_DW_DMAC_PCI)	+= dw_dmac_pci.o
 dw_dmac_pci-y			:= pci.o
diff --git a/drivers/dma/dw/rzn1-dmamux.c b/drivers/dma/dw/rzn1-dmamux.c
new file mode 100644
index 000000000000..29e4a0d86f8b
--- /dev/null
+++ b/drivers/dma/dw/rzn1-dmamux.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2022 Schneider-Electric
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com
+ * Based on TI crossbar driver written by Peter Ujfalusi <peter.ujfalusi@ti.com>
+ */
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/slab.h>
+#include <linux/soc/renesas/r9a06g032-sysctrl.h>
+
+#define RZN1_DMAMUX_LINES 64
+#define RZN1_DMAMUX_SPLIT 16
+
+struct rzn1_dmamux_data {
+	struct dma_router dmarouter;
+	u32 used_chans;
+	struct mutex lock;
+};
+
+struct rzn1_dmamux_map {
+	unsigned int req_idx;
+};
+
+static void rzn1_dmamux_free(struct device *dev, void *route_data)
+{
+	struct rzn1_dmamux_data *dmamux = dev_get_drvdata(dev);
+	struct rzn1_dmamux_map *map = route_data;
+
+	dev_dbg(dev, "Unmapping DMAMUX request %u\n", map->req_idx);
+
+	mutex_lock(&dmamux->lock);
+	dmamux->used_chans &= ~BIT(map->req_idx);
+	mutex_unlock(&dmamux->lock);
+
+	kfree(map);
+}
+
+static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
+					struct of_dma *ofdma)
+{
+	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
+	struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
+	struct rzn1_dmamux_map *map;
+	unsigned int dmac_idx, chan, val;
+	u32 mask;
+	int ret;
+
+	if (dma_spec->args_count != 6)
+		return ERR_PTR(-EINVAL);
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (!map)
+		return ERR_PTR(-ENOMEM);
+
+	chan = dma_spec->args[0];
+	map->req_idx = dma_spec->args[4];
+	val = dma_spec->args[5];
+	dma_spec->args_count -= 2;
+
+	if (chan >= RZN1_DMAMUX_SPLIT) {
+		dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
+		ret = -EINVAL;
+		goto free_map;
+	}
+
+	if (map->req_idx >= RZN1_DMAMUX_LINES ||
+	    (map->req_idx % RZN1_DMAMUX_SPLIT) != chan) {
+		dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
+		ret = -EINVAL;
+		goto free_map;
+	}
+
+	dmac_idx = map->req_idx < RZN1_DMAMUX_SPLIT ? 0 : 1;
+	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
+	if (!dma_spec->np) {
+		dev_err(&pdev->dev, "Can't get DMA master\n");
+		ret = -EINVAL;
+		goto free_map;
+	}
+
+	dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
+		map->req_idx, dmac_idx, chan);
+
+	mask = BIT(map->req_idx);
+	mutex_lock(&dmamux->lock);
+	dmamux->used_chans |= mask;
+	ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
+	mutex_unlock(&dmamux->lock);
+	if (ret)
+		goto free_mux;
+
+	return map;
+
+free_mux:
+	mutex_lock(&dmamux->lock);
+	dmamux->used_chans &= ~mask;
+	mutex_unlock(&dmamux->lock);
+free_map:
+	kfree(map);
+
+	return ERR_PTR(ret);
+}
+
+static const struct of_device_id rzn1_dmac_match[] = {
+	{ .compatible = "renesas,rzn1-dma" },
+	{}
+};
+
+static int rzn1_dmamux_probe(struct platform_device *pdev)
+{
+	struct device_node *mux_node = pdev->dev.of_node;
+	const struct of_device_id *match;
+	struct device_node *dmac_node;
+	struct rzn1_dmamux_data *dmamux;
+
+	dmamux = devm_kzalloc(&pdev->dev, sizeof(*dmamux), GFP_KERNEL);
+	if (!dmamux)
+		return -ENOMEM;
+
+	mutex_init(&dmamux->lock);
+
+	dmac_node = of_parse_phandle(mux_node, "dma-masters", 0);
+	if (!dmac_node)
+		return dev_err_probe(&pdev->dev, -ENODEV, "Can't get DMA master node\n");
+
+	match = of_match_node(rzn1_dmac_match, dmac_node);
+	of_node_put(dmac_node);
+	if (!match)
+		return dev_err_probe(&pdev->dev, -EINVAL, "DMA master is not supported\n");
+
+	dmamux->dmarouter.dev = &pdev->dev;
+	dmamux->dmarouter.route_free = rzn1_dmamux_free;
+
+	platform_set_drvdata(pdev, dmamux);
+
+	return of_dma_router_register(mux_node, rzn1_dmamux_route_allocate,
+				      &dmamux->dmarouter);
+}
+
+static const struct of_device_id rzn1_dmamux_match[] = {
+	{ .compatible = "renesas,rzn1-dmamux" },
+	{}
+};
+
+static struct platform_driver rzn1_dmamux_driver = {
+	.driver = {
+		.name = "renesas,rzn1-dmamux",
+		.of_match_table = rzn1_dmamux_match,
+	},
+	.probe	= rzn1_dmamux_probe,
+};
+module_platform_driver(rzn1_dmamux_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
+MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");
-- 
2.27.0

[PATCH v6 6/8] dmaengine: dw: Add RZN1 compatible

[Miquel Raynal]

The Renesas RZN1 DMA IP is very close to the original DW DMA IP, a DMA
router has been introduced to handle the wiring options that have been
added.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/dma/dw/platform.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 246118955877..47f2292dba98 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -137,6 +137,7 @@ static void dw_shutdown(struct platform_device *pdev)
 #ifdef CONFIG_OF
 static const struct of_device_id dw_dma_of_id_table[] = {
 	{ .compatible = "snps,dma-spear1340", .data = &dw_dma_chip_pdata },
+	{ .compatible = "renesas,rzn1-dma", .data = &dw_dma_chip_pdata },
 	{}
 };
 MODULE_DEVICE_TABLE(of, dw_dma_of_id_table);
-- 
2.27.0

[PATCH v6 7/8] ARM: dts: r9a06g032: Add the two DMA nodes

[Miquel Raynal]

Describe the two DMA controllers available on this SoC.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 arch/arm/boot/dts/r9a06g032.dtsi | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/arch/arm/boot/dts/r9a06g032.dtsi b/arch/arm/boot/dts/r9a06g032.dtsi
index 636a6ab31c58..839580ec21ee 100644
--- a/arch/arm/boot/dts/r9a06g032.dtsi
+++ b/arch/arm/boot/dts/r9a06g032.dtsi
@@ -200,6 +200,36 @@ nand_controller: nand-controller@40102000 {
 			status = "disabled";
 		};
 
+		dma0: dma-controller@40104000 {
+			compatible = "renesas,r9a06g032-dma", "renesas,rzn1-dma";
+			reg = <0x40104000 0x1000>;
+			interrupts = <GIC_SPI 56 IRQ_TYPE_LEVEL_HIGH>;
+			clock-names = "hclk";
+			clocks = <&sysctrl R9A06G032_HCLK_DMA0>;
+			dma-channels = <8>;
+			dma-requests = <16>;
+			dma-masters = <1>;
+			#dma-cells = <3>;
+			block_size = <0xfff>;
+			data_width = <3>;
+			status = "disabled";
+		};
+
+		dma1: dma-controller@40105000 {
+			compatible = "renesas,r9a06g032-dma", "renesas,rzn1-dma";
+			reg = <0x40105000 0x1000>;
+			interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>;
+			clock-names = "hclk";
+			clocks = <&sysctrl R9A06G032_HCLK_DMA1>;
+			dma-channels = <8>;
+			dma-requests = <16>;
+			dma-masters = <1>;
+			#dma-cells = <3>;
+			block_size = <0xfff>;
+			data_width = <3>;
+			status = "disabled";
+		};
+
 		gic: interrupt-controller@44101000 {
 			compatible = "arm,gic-400", "arm,cortex-a7-gic";
 			interrupt-controller;
-- 
2.27.0

[PATCH v6 8/8] ARM: dts: r9a06g032: Describe the DMA router

[Miquel Raynal]

There is a dmamux on this SoC which allows picking two different sources
for a single DMA request.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 arch/arm/boot/dts/r9a06g032.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm/boot/dts/r9a06g032.dtsi b/arch/arm/boot/dts/r9a06g032.dtsi
index 839580ec21ee..c854aa4cfa77 100644
--- a/arch/arm/boot/dts/r9a06g032.dtsi
+++ b/arch/arm/boot/dts/r9a06g032.dtsi
@@ -91,6 +91,16 @@ sysctrl: system-controller@4000c000 {
 			clocks = <&ext_mclk>, <&ext_rtc_clk>,
 					<&ext_jtag_clk>, <&ext_rgmii_ref>;
 			clock-names = "mclk", "rtc", "jtag", "rgmii_ref_ext";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			dmamux: dma-router@a0 {
+				compatible = "renesas,rzn1-dmamux";
+				reg = <0xa0 4>;
+				#dma-cells = <6>;
+				dma-requests = <32>;
+				dma-masters = <&dma0 &dma1>;
+			};
 		};
 
 		uart0: serial@40060000 {
-- 
2.27.0

Re: [PATCH v6 5/8] dmaengine: dw: dmamux: Introduce RZN1 DMA router support

[Ilpo Järvinen]

On Mon, 4 Apr 2022, Miquel Raynal wrote:

> The Renesas RZN1 DMA IP is based on a DW core, with eg. an additional
> dmamux register located in the system control area which can take up to
> 32 requests (16 per DMA controller). Each DMA channel can be wired to
> two different peripherals.
> 
> We need two additional information from the 'dmas' property: the channel
> (bit in the dmamux register) that must be accessed and the value of the
> mux for this channel.
> 
> Aside from the driver introduction, as these devices are described as
> subnodes of the system controller, we also need the system controller
> (clock) driver to populate its children manually. Starting from now on,
> one child can be the dmamux.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---

> +static void *rzn1_dmamux_route_allocate(struct of_phandle_args *dma_spec,
> +					struct of_dma *ofdma)
> +{
> +	struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
> +	struct rzn1_dmamux_data *dmamux = platform_get_drvdata(pdev);
> +	struct rzn1_dmamux_map *map;
> +	unsigned int dmac_idx, chan, val;
> +	u32 mask;
> +	int ret;
> +
> +	if (dma_spec->args_count != 6)
> +		return ERR_PTR(-EINVAL);
> +
> +	map = kzalloc(sizeof(*map), GFP_KERNEL);
> +	if (!map)
> +		return ERR_PTR(-ENOMEM);
> +
> +	chan = dma_spec->args[0];
> +	map->req_idx = dma_spec->args[4];
> +	val = dma_spec->args[5];
> +	dma_spec->args_count -= 2;
> +
> +	if (chan >= RZN1_DMAMUX_SPLIT) {
> +		dev_err(&pdev->dev, "Invalid DMA request line: %u\n", chan);
> +		ret = -EINVAL;
> +		goto free_map;
> +	}
> +
> +	if (map->req_idx >= RZN1_DMAMUX_LINES ||
> +	    (map->req_idx % RZN1_DMAMUX_SPLIT) != chan) {
> +		dev_err(&pdev->dev, "Invalid MUX request line: %u\n", map->req_idx);
> +		ret = -EINVAL;
> +		goto free_map;
> +	}
> +
> +	dmac_idx = map->req_idx < RZN1_DMAMUX_SPLIT ? 0 : 1;
> +	dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", dmac_idx);
> +	if (!dma_spec->np) {
> +		dev_err(&pdev->dev, "Can't get DMA master\n");
> +		ret = -EINVAL;
> +		goto free_map;
> +	}
> +
> +	dev_dbg(&pdev->dev, "Mapping DMAMUX request %u to DMAC%u request %u\n",
> +		map->req_idx, dmac_idx, chan);
> +
> +	mask = BIT(map->req_idx);
> +	mutex_lock(&dmamux->lock);
> +	dmamux->used_chans |= mask;
> +	ret = r9a06g032_sysctrl_set_dmamux(mask, val ? mask : 0);
> +	mutex_unlock(&dmamux->lock);
> +	if (ret)
> +		goto free_mux;

Move this check before the unlock. Then free_mux path doesn't need to do
(re)lock as the mutex is still held. You might also want to consider 
renaming the label e.g. to chan_release_and_unlock.

> +
> +	return map;
> +
> +free_mux:
> +	mutex_lock(&dmamux->lock);
> +	dmamux->used_chans &= ~mask;
> +	mutex_unlock(&dmamux->lock);
> +free_map:
> +	kfree(map);
> +
> +	return ERR_PTR(ret);
> +}


-- 
 i.

Re: [PATCH v6 0/8] RZN1 DMA support

[Geert Uytterhoeven]

Hi Miquel,

On Mon, Apr 4, 2022 at 3:39 PM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> Here is a first series bringing DMA support to RZN1 platforms. Soon a
> second series will come with changes made to the UART controller
> driver, in order to interact with the RZN1 DMA controller.
>
> Stephen acked the sysctrl patch (in the clk driver) but somehow I feel
> like it would be good to have this patch applied on both sides
> (dmaengine and clk) because more changes will depend on the addition of
> this helper, that are not related to DMA at all. I'll let you folks
> figure out what is best.
>
> Cheers,
> Miquèl
>
> Changes in v6:
> * Added Stephen's acks.

Looks like you forgot to add the ack?

> * Fixed an extra newline added in the middle of nowhere.
> * Rebased on top of v5.18-rc1.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v6 0/8] RZN1 DMA support

[Miquel Raynal]

Hi Geert,

geert@linux-m68k.org wrote on Mon, 4 Apr 2022 16:48:58 +0200:

> Hi Miquel,
> 
> On Mon, Apr 4, 2022 at 3:39 PM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > Here is a first series bringing DMA support to RZN1 platforms. Soon a
> > second series will come with changes made to the UART controller
> > driver, in order to interact with the RZN1 DMA controller.
> >
> > Stephen acked the sysctrl patch (in the clk driver) but somehow I feel
> > like it would be good to have this patch applied on both sides
> > (dmaengine and clk) because more changes will depend on the addition of
> > this helper, that are not related to DMA at all. I'll let you folks
> > figure out what is best.
> >
> > Cheers,
> > Miquèl
> >
> > Changes in v6:
> > * Added Stephen's acks.  
> 
> Looks like you forgot to add the ack?

Mmmh .____.

I have several series queued and I did apply Stephen's tag to
the wrong patch without noticing. Kudos for catching this. I will send
an updated version with it and Ilpo's comment addressed later this week.
In the mean time if there is anything else, let me know.

Thanks,
Miquèl

Re: [PATCH v6 5/8] dmaengine: dw: dmamux: Introduce RZN1 DMA router support

[Vinod Koul]

On 04-04-22, 15:39, Miquel Raynal wrote:
> The Renesas RZN1 DMA IP is based on a DW core, with eg. an additional
> dmamux register located in the system control area which can take up to
> 32 requests (16 per DMA controller). Each DMA channel can be wired to
> two different peripherals.
> 
> We need two additional information from the 'dmas' property: the channel
> (bit in the dmamux register) that must be accessed and the value of the
> mux for this channel.
> 
> Aside from the driver introduction, as these devices are described as
> subnodes of the system controller, we also need the system controller
> (clock) driver to populate its children manually. Starting from now on,
> one child can be the dmamux.
> 
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/clk/renesas/r9a06g032-clocks.c |   3 +-

This should be a different patch, not in this...

> +++ b/drivers/dma/dw/rzn1-dmamux.c
> @@ -0,0 +1,157 @@
> +// SPDX-License-Identifier: GPL-2.0-only

...

> +
> +MODULE_LICENSE("GPL");

This is not consistent with the SPDX tag..

> +MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com");
> +MODULE_DESCRIPTION("Renesas RZ/N1 DMAMUX driver");
> -- 
> 2.27.0

-- 
~Vinod

Re: [PATCH v6 5/8] dmaengine: dw: dmamux: Introduce RZN1 DMA router support

[Andy Shevchenko]

On Tue, Apr 05, 2022 at 11:27:12AM +0530, Vinod Koul wrote:
> On 04-04-22, 15:39, Miquel Raynal wrote:

...

> > +MODULE_LICENSE("GPL");
> 
> This is not consistent with the SPDX tag..

Actually it is. "GPLv2" is obsolete form, in new code we are supposed using
"GPL" as per Documentation.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 5/8] dmaengine: dw: dmamux: Introduce RZN1 DMA router support

[Vinod Koul]

On 05-04-22, 10:07, Andy Shevchenko wrote:
> On Tue, Apr 05, 2022 at 11:27:12AM +0530, Vinod Koul wrote:
> > On 04-04-22, 15:39, Miquel Raynal wrote:
> 
> ...
> 
> > > +MODULE_LICENSE("GPL");
> > 
> > This is not consistent with the SPDX tag..
> 
> Actually it is. "GPLv2" is obsolete form, in new code we are supposed using
> "GPL" as per Documentation.

Yes this has been updated, thanks for pointing out.

-- 
~Vinod