[PATCH v2 mailbox 0/3] Armada 37xx mailbox support

[PATCH v2 mailbox 0/3] Armada 37xx mailbox support

[Marek Behún]

Hi,
this is the second version of patches I sent in December, rebased onto
current linux/master.

Changes since previous version:
 - compatible string changed not to use wildcards, as requested by
   Rob Herring

Marek

Marek Behún (3):
  mailbox: Add support for Armada 37xx rWTM mailbox
  dt-bindings: mailbox: Document armada-37xx-rwtm-mailbox binding
  arm64: dts: marvell: armada-37xx: add mailbox node

 .../mailbox/armada-37xx-rwtm-mailbox.txt      |  16 ++
 arch/arm64/boot/dts/marvell/armada-37xx.dtsi  |   7 +
 drivers/mailbox/Kconfig                       |  10 +
 drivers/mailbox/Makefile                      |   2 +
 drivers/mailbox/armada-37xx-rwtm-mailbox.c    | 227 ++++++++++++++++++
 include/linux/armada-37xx-rwtm-mailbox.h      |  23 ++
 6 files changed, 285 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt
 create mode 100644 drivers/mailbox/armada-37xx-rwtm-mailbox.c
 create mode 100644 include/linux/armada-37xx-rwtm-mailbox.h

-- 
2.19.2


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[PATCH v2 mailbox 1/3] mailbox: Add support for Armada 37xx rWTM mailbox

[Marek Behún]

This adds support for the mailbox via which the kernel can communicate
with the firmware running on the secure processor of the Armada 37xx
SOC.

The rWTM secure processor has access to internal eFuses and
cryptographic circuits, such as the Entropy Bit Generator to generate
true random numbers.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 drivers/mailbox/Kconfig                    |  10 +
 drivers/mailbox/Makefile                   |   2 +
 drivers/mailbox/armada-37xx-rwtm-mailbox.c | 227 +++++++++++++++++++++
 include/linux/armada-37xx-rwtm-mailbox.h   |  23 +++
 4 files changed, 262 insertions(+)
 create mode 100644 drivers/mailbox/armada-37xx-rwtm-mailbox.c
 create mode 100644 include/linux/armada-37xx-rwtm-mailbox.h

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 3eeb12e93e98..939927290ac6 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -41,6 +41,16 @@ config PL320_MBOX
 	  Management Engine, primarily for cpufreq. Say Y here if you want
 	  to use the PL320 IPCM support.
 
+config ARMADA_37XX_RWTM_MBOX
+	tristate "Armada 37xx rWTM BIU Mailbox"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	help
+	  Mailbox implementation for communication with the the firmware
+	  running on the Cortex-M3 rWTM secure processor of the Armada 37xx
+	  SOC. Say Y here if you are building for such a device (for example
+	  the Turris Mox router).
+
 config OMAP2PLUS_MBOX
 	tristate "OMAP2+ Mailbox framework support"
 	depends on ARCH_OMAP2PLUS
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index c818b5d011ae..792894db6b43 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -9,6 +9,8 @@ obj-$(CONFIG_ARM_MHU)	+= arm_mhu.o
 
 obj-$(CONFIG_IMX_MBOX)	+= imx-mailbox.o
 
+obj-$(CONFIG_ARMADA_37XX_RWTM_MBOX)	+= armada-37xx-rwtm-mailbox.o
+
 obj-$(CONFIG_PLATFORM_MHU)	+= platform_mhu.o
 
 obj-$(CONFIG_PL320_MBOX)	+= pl320-ipc.o
diff --git a/drivers/mailbox/armada-37xx-rwtm-mailbox.c b/drivers/mailbox/armada-37xx-rwtm-mailbox.c
new file mode 100644
index 000000000000..af8b002e4732
--- /dev/null
+++ b/drivers/mailbox/armada-37xx-rwtm-mailbox.c
@@ -0,0 +1,227 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * rWTM BIU Mailbox driver for Armada 37xx
+ *
+ * Author: Marek Behun <marek.behun@nic.cz>
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/armada-37xx-rwtm-mailbox.h>
+
+#define DRIVER_NAME	"armada-37xx-rwtm-mailbox"
+
+/* relative to rWTM BIU Mailbox Registers */
+#define RWTM_MBOX_PARAM(i)		(0x0 + ((i) << 2))
+#define RWTM_MBOX_COMMAND		0x40
+#define RWTM_MBOX_RETURN_STATUS		0x80
+#define RWTM_MBOX_STATUS(i)		(0x84 + ((i) << 2))
+#define RWTM_MBOX_FIFO_STATUS		0xc4
+#define FIFO_STS_RDY			0x100
+#define FIFO_STS_CNTR_MASK		0x7
+#define FIFO_STS_CNTR_MAX		4
+
+#define RWTM_HOST_INT_RESET		0xc8
+#define RWTM_HOST_INT_MASK		0xcc
+#define SP_CMD_COMPLETE			BIT(0)
+#define SP_CMD_QUEUE_FULL_ACCESS	BIT(17)
+#define SP_CMD_QUEUE_FULL		BIT(18)
+
+struct a37xx_mbox {
+	struct device *dev;
+	struct mbox_controller controller;
+	void __iomem *base;
+	int irq;
+};
+
+static void a37xx_mbox_receive(struct mbox_chan *chan)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	struct armada_37xx_rwtm_rx_msg rx_msg;
+	int i;
+
+	rx_msg.retval = readl(mbox->base + RWTM_MBOX_RETURN_STATUS);
+	for (i = 0; i < 16; ++i)
+		rx_msg.status[i] = readl(mbox->base + RWTM_MBOX_STATUS(i));
+
+	mbox_chan_received_data(chan, &rx_msg);
+}
+
+static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+	struct a37xx_mbox *mbox = chan->con_priv;
+	u32 reg;
+
+	reg = readl(mbox->base + RWTM_HOST_INT_RESET);
+
+	if (reg & SP_CMD_COMPLETE)
+		a37xx_mbox_receive(chan);
+
+	if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL))
+		dev_err(mbox->dev, "Secure processor command queue full\n");
+
+	writel(reg, mbox->base + RWTM_HOST_INT_RESET);
+	if (reg)
+		mbox_chan_txdone(chan, 0);
+
+	return reg ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	struct armada_37xx_rwtm_tx_msg *msg = data;
+	int i;
+	u32 reg;
+
+	if (!data)
+		return -EINVAL;
+
+	reg = readl(mbox->base + RWTM_MBOX_FIFO_STATUS);
+	if (!(reg & FIFO_STS_RDY)) {
+		dev_err(mbox->dev, "Secure processor not ready\n");
+		return -EAGAIN;
+	}
+
+	if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) {
+		dev_err(mbox->dev, "Secure processor command queue full\n");
+		return -EBUSY;
+	}
+
+	for (i = 0; i < 16; ++i)
+		writel(msg->args[i], mbox->base + RWTM_MBOX_PARAM(i));
+	writel(msg->command, mbox->base + RWTM_MBOX_COMMAND);
+
+	return 0;
+}
+
+static int a37xx_mbox_startup(struct mbox_chan *chan)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	u32 reg;
+	int ret;
+
+	ret = devm_request_irq(mbox->dev, mbox->irq, a37xx_mbox_irq_handler, 0,
+			       DRIVER_NAME, chan);
+	if (ret < 0) {
+		dev_err(mbox->dev, "Cannot request irq\n");
+		return ret;
+	}
+
+	/* enable IRQ generation */
+	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
+	reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL);
+	writel(reg, mbox->base + RWTM_HOST_INT_MASK);
+
+	return 0;
+}
+
+static void a37xx_mbox_shutdown(struct mbox_chan *chan)
+{
+	u32 reg;
+	struct a37xx_mbox *mbox = chan->con_priv;
+
+	/* disable interrupt generation */
+	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
+	reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL;
+	writel(reg, mbox->base + RWTM_HOST_INT_MASK);
+
+	devm_free_irq(mbox->dev, mbox->irq, chan);
+}
+
+static const struct mbox_chan_ops a37xx_mbox_ops = {
+	.send_data	= a37xx_mbox_send_data,
+	.startup	= a37xx_mbox_startup,
+	.shutdown	= a37xx_mbox_shutdown,
+};
+
+static int armada_37xx_mbox_probe(struct platform_device *pdev)
+{
+	struct a37xx_mbox *mbox;
+	struct resource *regs;
+	struct mbox_chan *chans;
+	int ret;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	/* Allocated one channel */
+	chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	mbox->base = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(mbox->base)) {
+		dev_err(&pdev->dev, "ioremap failed\n");
+		return PTR_ERR(mbox->base);
+	}
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq < 0) {
+		dev_err(&pdev->dev, "Cannot get irq\n");
+		return mbox->irq;
+	}
+
+	mbox->dev = &pdev->dev;
+
+	/* Hardware supports only one channel. */
+	chans[0].con_priv = mbox;
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = chans;
+	mbox->controller.ops = &a37xx_mbox_ops;
+	mbox->controller.txdone_irq = true;
+
+	ret = mbox_controller_register(&mbox->controller);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register mailbox controller\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	return ret;
+}
+
+static int armada_37xx_mbox_remove(struct platform_device *pdev)
+{
+	struct a37xx_mbox *mbox = platform_get_drvdata(pdev);
+
+	if (!mbox)
+		return -EINVAL;
+
+	mbox_controller_unregister(&mbox->controller);
+
+	return 0;
+}
+
+static const struct of_device_id armada_37xx_mbox_match[] = {
+	{ .compatible = "marvell,armada-3700-rwtm-mailbox" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match);
+
+static struct platform_driver armada_37xx_mbox_driver = {
+	.probe	= armada_37xx_mbox_probe,
+	.remove	= armada_37xx_mbox_remove,
+	.driver	= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= armada_37xx_mbox_match,
+	},
+};
+
+module_platform_driver(armada_37xx_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx");
+MODULE_AUTHOR("Marek Behun <marek.behun@nic.cz>");
diff --git a/include/linux/armada-37xx-rwtm-mailbox.h b/include/linux/armada-37xx-rwtm-mailbox.h
new file mode 100644
index 000000000000..57bb54f6767a
--- /dev/null
+++ b/include/linux/armada-37xx-rwtm-mailbox.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * rWTM BIU Mailbox driver for Armada 37xx
+ *
+ * Author: Marek Behun <marek.behun@nic.cz>
+ */
+
+#ifndef _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_
+#define _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_
+
+#include <linux/types.h>
+
+struct armada_37xx_rwtm_tx_msg {
+	u16 command;
+	u32 args[16];
+};
+
+struct armada_37xx_rwtm_rx_msg {
+	u32 retval;
+	u32 status[16];
+};
+
+#endif /* _LINUX_ARMADA_37XX_RWTM_MAILBOX_H_ */
-- 
2.19.2


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[PATCH v2 mailbox 2/3] dt-bindings: mailbox: Document armada-37xx-rwtm-mailbox binding

[Marek Behún]

This adds device tree binding documentation for the rWTM BIU mailbox
driver on the Armada 37xx SOC (EspressoBin, Turris Mox).

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
---
 .../mailbox/armada-37xx-rwtm-mailbox.txt         | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt

diff --git a/Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt b/Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt
new file mode 100644
index 000000000000..282ab81a4ea6
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt
@@ -0,0 +1,16 @@
+* rWTM BIU Mailbox driver for Armada 37xx
+
+Required properties:
+- compatible:	must be "marvell,armada-3700-rwtm-mailbox"
+- reg:		physical base address of the mailbox and length of memory mapped
+		region
+- interrupts:	the IRQ line for the mailbox
+- #mbox-cells:	must be 1
+
+Example:
+	rwtm: mailbox@b0000 {
+		compatible = "marvell,armada-3700-rwtm-mailbox";
+		reg = <0xb0000 0x100>;
+		interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
+		#mbox-cells = <1>;
+	};
-- 
2.19.2


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[PATCH v2 mailbox 3/3] arm64: dts: marvell: armada-37xx: add mailbox node

[Marek Behún]

This adds the rWTM BIU mailbox node for communication with the secure
processor.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
---
 arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
index e05594ea15fb..ecbc293dc8f1 100644
--- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
+++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
@@ -344,6 +344,13 @@
 				clocks = <&nb_periph_clk 15>;
 			};
 
+			rwtm: mailbox@b0000 {
+				compatible = "marvell,armada-3700-rwtm-mailbox";
+				reg = <0xb0000 0x100>;
+				interrupts = <GIC_SPI 18 IRQ_TYPE_LEVEL_HIGH>;
+				#mbox-cells = <1>;
+			};
+
 			sdhci1: sdhci@d0000 {
 				compatible = "marvell,armada-3700-sdhci",
 					     "marvell,sdhci-xenon";
-- 
2.19.2


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Re: [PATCH v2 mailbox 2/3] dt-bindings: mailbox: Document armada-37xx-rwtm-mailbox binding

[Rob Herring]

On Fri,  1 Mar 2019 05:23:40 +0100, =?UTF-8?q?Marek=20Beh=C3=BAn?= wrote:
> This adds device tree binding documentation for the rWTM BIU mailbox
> driver on the Armada 37xx SOC (EspressoBin, Turris Mox).
> 
> Signed-off-by: Marek Behún <marek.behun@nic.cz>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> ---
>  .../mailbox/armada-37xx-rwtm-mailbox.txt         | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mailbox/armada-37xx-rwtm-mailbox.txt
> 

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

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