Commit d0054a47 authored by Conor Dooley's avatar Conor Dooley Committed by Nicolas Ferre
Browse files

soc: add microchip polarfire soc system controller 



This driver provides an interface for other drivers to access the
functions of the system controller on the Microchip PolarFire SoC.

Signed-off-by: default avatarConor Dooley <conor.dooley@microchip.com>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220217101349.2374873-2-conor.dooley@microchip.com
parent f8e0f301

drivers/soc/Kconfig

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@@ -13,6 +13,7 @@ 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"

drivers/soc/Makefile

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@@ -18,6 +18,7 @@ obj-y += 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/

drivers/soc/microchip/Kconfig

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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.

drivers/soc/microchip/Makefile

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obj-$(CONFIG_POLARFIRE_SOC_SYS_CTRL)	+= mpfs-sys-controller.o

drivers/soc/microchip/mpfs-sys-controller.c

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+194 −0
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// SPDX-License-Identifier: GPL-2.0

/*

 * Microchip PolarFire SoC (MPFS) system controller driver

 *

 * Copyright (c) 2020-2021 Microchip Corporation. All rights reserved.

 *

 * Author: Conor Dooley <conor.dooley@microchip.com>

 *

 */



#include <linux/slab.h>

#include <linux/kref.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;

	struct kref consumers;

};



int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg)

{

	int ret, err;



	err = mutex_lock_interruptible(&transaction_lock);

	if (err)

		return err;



	reinit_completion(&sys_controller->c);



	ret = mbox_send_message(sys_controller->chan, msg);

	if (ret >= 0) {

		if (wait_for_completion_timeout(&sys_controller->c, HZ)) {

			ret = 0;

		} else {

			ret = -ETIMEDOUT;

			dev_warn(sys_controller->client.dev,

				 "MPFS sys controller transaction timeout\n");

		}

	} else {

		dev_err(sys_controller->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 *sys_controller =

		container_of(client, struct mpfs_sys_controller, client);



	complete(&sys_controller->c);

}



static void mpfs_sys_controller_delete(struct kref *kref)

{

	struct mpfs_sys_controller *sys_controller = container_of(kref, struct mpfs_sys_controller,

					       consumers);



	mbox_free_channel(sys_controller->chan);

	kfree(sys_controller);

}



void mpfs_sys_controller_put(void *data)

{

	struct mpfs_sys_controller *sys_controller = data;



	kref_put(&sys_controller->consumers, mpfs_sys_controller_delete);

}

EXPORT_SYMBOL(mpfs_sys_controller_put);



static struct platform_device subdevs[] = {

	{

		.name		= "mpfs-rng",

		.id		= -1,

	},

	{

		.name		= "mpfs-generic-service",

		.id		= -1,

	}

};



static int mpfs_sys_controller_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct mpfs_sys_controller *sys_controller;

	int i;



	sys_controller = devm_kzalloc(dev, sizeof(*sys_controller), GFP_KERNEL);

	if (!sys_controller)

		return -ENOMEM;



	sys_controller->client.dev = dev;

	sys_controller->client.rx_callback = rx_callback;

	sys_controller->client.tx_block = 1U;



	sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);

	if (IS_ERR(sys_controller->chan))

		return dev_err_probe(dev, PTR_ERR(sys_controller->chan),

				     "Failed to get mbox channel\n");



	init_completion(&sys_controller->c);

	kref_init(&sys_controller->consumers);



	platform_set_drvdata(pdev, sys_controller);



	dev_info(&pdev->dev, "Registered MPFS system controller\n");



	for (i = 0; i < ARRAY_SIZE(subdevs); i++) {

		subdevs[i].dev.parent = dev;

		if (platform_device_register(&subdevs[i]))

			dev_warn(dev, "Error registering sub device %s\n", subdevs[i].name);

	}



	return 0;

}



static int mpfs_sys_controller_remove(struct platform_device *pdev)

{

	struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev);



	mpfs_sys_controller_put(sys_controller);



	return 0;

}



static const struct of_device_id mpfs_sys_controller_of_match[] = {

	{.compatible = "microchip,mpfs-sys-controller", },

	{},

};

MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match);



struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev)

{

	const struct of_device_id *match;

	struct mpfs_sys_controller *sys_controller;

	int ret;



	if (!dev->parent)

		goto err_no_device;



	match = of_match_node(mpfs_sys_controller_of_match,  dev->parent->of_node);

	of_node_put(dev->parent->of_node);

	if (!match)

		goto err_no_device;



	sys_controller = dev_get_drvdata(dev->parent);

	if (!sys_controller)

		goto err_bad_device;



	if (!kref_get_unless_zero(&sys_controller->consumers))

		goto err_bad_device;



	ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller);

	if (ret)

		return ERR_PTR(ret);



	return sys_controller;



err_no_device:

	dev_dbg(dev, "Parent device was not an MPFS system controller\n");

	return ERR_PTR(-ENODEV);



err_bad_device:

	dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n");

	return ERR_PTR(-EPROBE_DEFER);

}

EXPORT_SYMBOL(mpfs_sys_controller_get);



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,

	.remove = mpfs_sys_controller_remove,

};

module_platform_driver(mpfs_sys_controller_driver);



MODULE_LICENSE("GPL v2");

MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");

MODULE_DESCRIPTION("MPFS system controller driver");