[PATCH v9 4/5] soc: add polarfire soc system controller

[Conor.Dooley at microchip.com]

Just bumping this, rest of the series seems to have made it into 
5.14-rc* via the mailbox tree but this patch did not.
Assume the lack of any approvals caused it.
On 24/06/2021 16:01, conor.dooley at microchip.com wrote:
> From: Conor Dooley <conor.dooley at microchip.com>
>
> This driver provides an interface for other drivers to access the
> functions of the system controller on the Microchip PolarFire SoC.
>
> Signed-off-by: Conor Dooley <conor.dooley at microchip.com>
> ---
>   drivers/soc/Kconfig                         |   1 +
>   drivers/soc/Makefile                        |   1 +
>   drivers/soc/microchip/Kconfig               |  10 ++
>   drivers/soc/microchip/Makefile              |   1 +
>   drivers/soc/microchip/mpfs-sys-controller.c | 121 ++++++++++++++++++++
>   5 files changed, 134 insertions(+)
>   create mode 100644 drivers/soc/microchip/Kconfig
>   create mode 100644 drivers/soc/microchip/Makefile
>   create mode 100644 drivers/soc/microchip/mpfs-sys-controller.c
>
> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
> index e8a30c4c5aec..b33142e020e0 100644
> --- a/drivers/soc/Kconfig
> +++ b/drivers/soc/Kconfig
> @@ -12,6 +12,7 @@ source "drivers/soc/imx/Kconfig"
>   source "drivers/soc/ixp4xx/Kconfig"
>   source "drivers/soc/litex/Kconfig"
>   source "drivers/soc/mediatek/Kconfig"
> +source "drivers/soc/microchip/Kconfig"
>   source "drivers/soc/qcom/Kconfig"
>   source "drivers/soc/renesas/Kconfig"
>   source "drivers/soc/rockchip/Kconfig"
> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
> index f678e4d9e585..10cfdcd972c7 100644
> --- a/drivers/soc/Makefile
> +++ b/drivers/soc/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_IXP4XX)	+= ixp4xx/
>   obj-$(CONFIG_SOC_XWAY)		+= lantiq/
>   obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex/
>   obj-y				+= mediatek/
> +obj-y				+= microchip/
>   obj-y				+= amlogic/
>   obj-y				+= qcom/
>   obj-y				+= renesas/
> diff --git a/drivers/soc/microchip/Kconfig b/drivers/soc/microchip/Kconfig
> new file mode 100644
> index 000000000000..eb656b33156b
> --- /dev/null
> +++ b/drivers/soc/microchip/Kconfig
> @@ -0,0 +1,10 @@
> +config POLARFIRE_SOC_SYS_CTRL
> +	tristate "POLARFIRE_SOC_SYS_CTRL"
> +	depends on POLARFIRE_SOC_MAILBOX
> +	help
> +	  This driver adds support for the PolarFire SoC (MPFS) system controller.
> +
> +	  To compile this driver as a module, choose M here. the
> +	  module will be called mpfs_system_controller.
> +
> +	  If unsure, say N.
> diff --git a/drivers/soc/microchip/Makefile b/drivers/soc/microchip/Makefile
> new file mode 100644
> index 000000000000..14489919fe4b
> --- /dev/null
> +++ b/drivers/soc/microchip/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_POLARFIRE_SOC_SYS_CTRL)	+= mpfs-sys-controller.o
> diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/microchip/mpfs-sys-controller.c
> new file mode 100644
> index 000000000000..b5c23cb5df2c
> --- /dev/null
> +++ b/drivers/soc/microchip/mpfs-sys-controller.c
> @@ -0,0 +1,121 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Microchip PolarFire SoC (MPFS) system controller driver
> + *
> + * Copyright (c) 2020 Microchip Corporation. All rights reserved.
> + *
> + * Author: Conor Dooley <conor.dooley at microchip.com>
> + *
> + */
> +
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/of_platform.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/platform_device.h>
> +#include <soc/microchip/mpfs.h>
> +
> +static DEFINE_MUTEX(transaction_lock);
> +
> +struct mpfs_sys_controller {
> +	struct mbox_client client;
> +	struct mbox_chan *chan;
> +	struct completion c;
> +	u32 enabled;
> +};
> +
> +int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg)
> +{
> +	int ret;
> +
> +	ret = mutex_lock_interruptible(&transaction_lock);
> +	if (ret)
> +		return ret;
> +
> +	reinit_completion(&mpfs_client->c);
> +
> +	ret = mbox_send_message(mpfs_client->chan, msg);
> +	if (ret >= 0) {
> +		if (wait_for_completion_timeout(&mpfs_client->c, HZ)) {
> +			ret = 0;
> +		} else {
> +			ret = -ETIMEDOUT;
> +			dev_warn(mpfs_client->client.dev, "MPFS sys controller transaction timeout\n");
> +		}
> +	} else {
> +		dev_err(mpfs_client->client.dev,
> +			"mpfs sys controller transaction returned %d\n", ret);
> +	}
> +
> +	mutex_unlock(&transaction_lock);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(mpfs_blocking_transaction);
> +
> +static void rx_callback(struct mbox_client *client, void *msg)
> +{
> +	struct mpfs_sys_controller *mpfs_client =
> +		container_of(client, struct mpfs_sys_controller, client);
> +
> +	complete(&mpfs_client->c);
> +}
> +
> +static int mpfs_sys_controller_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mpfs_sys_controller *mpfs_client;
> +
> +	mpfs_client = devm_kzalloc(dev, sizeof(*mpfs_client), GFP_KERNEL);
> +	if (!mpfs_client)
> +		return -ENOMEM;
> +
> +	mpfs_client->client.dev = dev;
> +	mpfs_client->client.rx_callback = rx_callback;
> +	mpfs_client->client.tx_block = 1U;
> +
> +	mpfs_client->chan = mbox_request_channel(&mpfs_client->client, 0);
> +	if (IS_ERR(mpfs_client->chan))
> +		return dev_err_probe(dev, PTR_ERR(mpfs_client->chan),
> +				     "Failed to get mbox channel\n");
> +
> +	init_completion(&mpfs_client->c);
> +
> +	platform_set_drvdata(pdev, mpfs_client);
> +
> +	dev_info(&pdev->dev, "Registered MPFS system controller driver\n");
> +
> +	return 0;
> +}
> +
> +struct mpfs_sys_controller *
> +mpfs_sys_controller_get(struct device_node *mss_node)
> +{
> +	struct platform_device *pdev = of_find_device_by_node(mss_node);
> +
> +	if (!pdev)
> +		return NULL;
> +
> +	return platform_get_drvdata(pdev);
> +}
> +EXPORT_SYMBOL(mpfs_sys_controller_get);
> +
> +static const struct of_device_id mpfs_sys_controller_of_match[] = {
> +	{.compatible = "microchip,polarfire-soc-sys-controller", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match);
> +
> +static struct platform_driver mpfs_sys_controller_driver = {
> +	.driver = {
> +		.name = "mpfs-sys-controller",
> +		.of_match_table = mpfs_sys_controller_of_match,
> +	},
> +	.probe = mpfs_sys_controller_probe,
> +};
> +module_platform_driver(mpfs_sys_controller_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Conor Dooley <conor.dooley at microchip.com>");
> +MODULE_DESCRIPTION("MPFS system controller driver");