Re: [PATCH v1 1/3] mailbox: Add support for Armada 37xx rWTM mailbox

Marek Behún
2018-12-19T15:31:40Z

I forgot to git add the header file containing definitions of
structures for messages :(. Will send in the next version.

On Mon, 17 Dec 2018 16:37:04 +0100
Marek Behún <marek.behun@nic.cz> wrote:

> 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
> +++++++++++++++++++++ 3 files changed, 239 insertions(+)
> create mode 100644 drivers/mailbox/armada-37xx-rwtm-mailbox.c
>
> 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..b8b3e8cd49f0
> --- /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-37xx-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>");