diff options
Diffstat (limited to 'drivers/soc/microchip/mpfs-sys-controller.c')
| -rw-r--r-- | drivers/soc/microchip/mpfs-sys-controller.c | 216 |
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 000000000..fbcd5fd24 --- /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"); |