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path: root/drivers/soc/microchip/mpfs-sys-controller.c
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-rw-r--r--drivers/soc/microchip/mpfs-sys-controller.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/soc/microchip/mpfs-sys-controller.c b/drivers/soc/microchip/mpfs-sys-controller.c
new file mode 100644
index 0000000000..fbcd5fd24d
--- /dev/null
+++ b/drivers/soc/microchip/mpfs-sys-controller.c
@@ -0,0 +1,216 @@
+// 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/jiffies.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/mailbox_client.h>
+#include <linux/platform_device.h>
+#include <soc/microchip/mpfs.h>
+
+/*
+ * This timeout must be long, as some services (example: image authentication)
+ * take significant time to complete
+ */
+#define MPFS_SYS_CTRL_TIMEOUT_MS 30000
+
+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)
+{
+ unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
+ int ret;
+
+ ret = mutex_lock_interruptible(&transaction_lock);
+ if (ret)
+ return ret;
+
+ reinit_completion(&sys_controller->c);
+
+ ret = mbox_send_message(sys_controller->chan, msg);
+ if (ret < 0) {
+ dev_warn(sys_controller->client.dev, "MPFS sys controller service timeout\n");
+ goto out;
+ }
+
+ /*
+ * Unfortunately, the system controller will only deliver an interrupt
+ * if a service succeeds. mbox_send_message() will block until the busy
+ * flag is gone. If the busy flag is gone but no interrupt has arrived
+ * to trigger the rx callback then the service can be deemed to have
+ * failed.
+ * The caller can then interrogate msg::response::resp_status to
+ * determine the cause of the failure.
+ * mbox_send_message() returns positive integers in the success path, so
+ * ret needs to be cleared if we do get an interrupt.
+ */
+ if (!wait_for_completion_timeout(&sys_controller->c, timeout)) {
+ ret = -EBADMSG;
+ dev_warn(sys_controller->client.dev, "MPFS sys controller service failed\n");
+ } else {
+ ret = 0;
+ }
+
+out:
+ mutex_unlock(&transaction_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(mpfs_blocking_transaction);
+
+static void mpfs_sys_controller_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);
+}
+
+static void mpfs_sys_controller_put(void *data)
+{
+ struct mpfs_sys_controller *sys_controller = data;
+
+ kref_put(&sys_controller->consumers, mpfs_sys_controller_delete);
+}
+
+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, ret;
+
+ sys_controller = kzalloc(sizeof(*sys_controller), GFP_KERNEL);
+ if (!sys_controller)
+ return -ENOMEM;
+
+ sys_controller->client.dev = dev;
+ sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback;
+ sys_controller->client.tx_block = 1U;
+ sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
+
+ sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);
+ if (IS_ERR(sys_controller->chan)) {
+ ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan),
+ "Failed to get mbox channel\n");
+ kfree(sys_controller);
+ return ret;
+ }
+
+ 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");