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: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220217101349.2374873-2-conor.dooley@microchip.com

diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index a8562678c437049d18050b0bad18461a7d398e5d..c5aae42673d3b89e821f74e8bbd2ce544f0610e1 100644 (file)
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -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"

diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index adb30c2d4feaa637cfb697fec78a236cdc8dbe3f..904eec2a7871325d0d7808206459551aed889525 100644 (file)
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -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/

diff --git a/drivers/soc/microchip/Kconfig b/drivers/soc/microchip/Kconfig
new file mode 100644 (file)
index 0000000..eb656b3
--- /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 (file)
index 0000000..1448991
--- /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 (file)
index 0000000..2f45359
--- /dev/null
+++ b/drivers/soc/microchip/mpfs-sys-controller.c
@@ -0,0 +1,194 @@
+// 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");

diff --git a/include/soc/microchip/mpfs.h b/include/soc/microchip/mpfs.h
index 2b64c95f3be555920f49f2e9d8f068ba94d7ddad..6466515262bdb380ba31000206eeddb018d42a3f 100644 (file)
--- a/include/soc/microchip/mpfs.h
+++ b/include/soc/microchip/mpfs.h
@@ -34,9 +34,9 @@ struct mpfs_mss_response {
 
 #if IS_ENABLED(CONFIG_POLARFIRE_SOC_SYS_CTRL)
 
-int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg);
+int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, struct mpfs_mss_msg *msg);
 
-struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node);
+struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev);
 
 #endif /* if IS_ENABLED(CONFIG_POLARFIRE_SOC_SYS_CTRL) */