From 3a3d2f6a4c64b9e709edc13b685ce46c8629060e Mon Sep 17 00:00:00 2001 From: Andrew Jeffery Date: Tue, 8 Jun 2021 20:17:52 +0930 Subject: [PATCH] ipmi: kcs_bmc: Add serio adaptor kcs_bmc_serio acts as a bridge between the KCS drivers in the IPMI subsystem and the existing userspace interfaces available through the serio subsystem. This is useful when userspace would like to make use of the BMC KCS devices for purposes that aren't IPMI. Signed-off-by: Andrew Jeffery Message-Id: <20210608104757.582199-12-andrew@aj.id.au> Reviewed-by: Zev Weiss Signed-off-by: Corey Minyard --- drivers/char/ipmi/Kconfig | 14 +++ drivers/char/ipmi/Makefile | 1 + drivers/char/ipmi/kcs_bmc_serio.c | 157 ++++++++++++++++++++++++++++++ 3 files changed, 172 insertions(+) create mode 100644 drivers/char/ipmi/kcs_bmc_serio.c diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig index bc5f81899b629..249b31197eeae 100644 --- a/drivers/char/ipmi/Kconfig +++ b/drivers/char/ipmi/Kconfig @@ -137,6 +137,20 @@ config IPMI_KCS_BMC_CDEV_IPMI This support is also available as a module. The module will be called kcs_bmc_cdev_ipmi. +config IPMI_KCS_BMC_SERIO + depends on IPMI_KCS_BMC && SERIO + tristate "SerIO adaptor for BMC KCS devices" + help + Adapts the BMC KCS device for the SerIO subsystem. This allows users + to take advantage of userspace interfaces provided by SerIO where + appropriate. + + Say YES if you wish to expose KCS devices on the BMC via SerIO + interfaces. + + This support is also available as a module. The module will be + called kcs_bmc_serio. + config ASPEED_BT_IPMI_BMC depends on ARCH_ASPEED || COMPILE_TEST depends on REGMAP && REGMAP_MMIO && MFD_SYSCON diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile index fcfa676afddbb..84f47d18007fb 100644 --- a/drivers/char/ipmi/Makefile +++ b/drivers/char/ipmi/Makefile @@ -23,6 +23,7 @@ obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o obj-$(CONFIG_IPMI_KCS_BMC) += kcs_bmc.o +obj-$(CONFIG_IPMI_KCS_BMC_SERIO) += kcs_bmc_serio.o obj-$(CONFIG_IPMI_KCS_BMC_CDEV_IPMI) += kcs_bmc_cdev_ipmi.o obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o diff --git a/drivers/char/ipmi/kcs_bmc_serio.c b/drivers/char/ipmi/kcs_bmc_serio.c new file mode 100644 index 0000000000000..7948cabde50b4 --- /dev/null +++ b/drivers/char/ipmi/kcs_bmc_serio.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Copyright (c) 2021 IBM Corp. */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "kcs_bmc_client.h" + +struct kcs_bmc_serio { + struct list_head entry; + + struct kcs_bmc_client client; + struct serio *port; + + spinlock_t lock; +}; + +static inline struct kcs_bmc_serio *client_to_kcs_bmc_serio(struct kcs_bmc_client *client) +{ + return container_of(client, struct kcs_bmc_serio, client); +} + +static irqreturn_t kcs_bmc_serio_event(struct kcs_bmc_client *client) +{ + struct kcs_bmc_serio *priv; + u8 handled = IRQ_NONE; + u8 status; + + priv = client_to_kcs_bmc_serio(client); + + spin_lock(&priv->lock); + + status = kcs_bmc_read_status(client->dev); + + if (status & KCS_BMC_STR_IBF) + handled = serio_interrupt(priv->port, kcs_bmc_read_data(client->dev), 0); + + spin_unlock(&priv->lock); + + return handled; +} + +static const struct kcs_bmc_client_ops kcs_bmc_serio_client_ops = { + .event = kcs_bmc_serio_event, +}; + +static int kcs_bmc_serio_open(struct serio *port) +{ + struct kcs_bmc_serio *priv = port->port_data; + + return kcs_bmc_enable_device(priv->client.dev, &priv->client); +} + +static void kcs_bmc_serio_close(struct serio *port) +{ + struct kcs_bmc_serio *priv = port->port_data; + + kcs_bmc_disable_device(priv->client.dev, &priv->client); +} + +static DEFINE_SPINLOCK(kcs_bmc_serio_instances_lock); +static LIST_HEAD(kcs_bmc_serio_instances); + +static int kcs_bmc_serio_add_device(struct kcs_bmc_device *kcs_bmc) +{ + struct kcs_bmc_serio *priv; + struct serio *port; + + priv = devm_kzalloc(kcs_bmc->dev, sizeof(*priv), GFP_KERNEL); + + /* Use kzalloc() as the allocation is cleaned up with kfree() via serio_unregister_port() */ + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!(priv && port)) + return -ENOMEM; + + port->id.type = SERIO_8042; + port->open = kcs_bmc_serio_open; + port->close = kcs_bmc_serio_close; + port->port_data = priv; + port->dev.parent = kcs_bmc->dev; + + spin_lock_init(&priv->lock); + priv->port = port; + priv->client.dev = kcs_bmc; + priv->client.ops = &kcs_bmc_serio_client_ops; + + spin_lock_irq(&kcs_bmc_serio_instances_lock); + list_add(&priv->entry, &kcs_bmc_serio_instances); + spin_unlock_irq(&kcs_bmc_serio_instances_lock); + + serio_register_port(port); + + dev_info(kcs_bmc->dev, "Initialised serio client for channel %d", kcs_bmc->channel); + + return 0; +} + +static int kcs_bmc_serio_remove_device(struct kcs_bmc_device *kcs_bmc) +{ + struct kcs_bmc_serio *priv = NULL, *pos; + + spin_lock_irq(&kcs_bmc_serio_instances_lock); + list_for_each_entry(pos, &kcs_bmc_serio_instances, entry) { + if (pos->client.dev == kcs_bmc) { + priv = pos; + list_del(&pos->entry); + break; + } + } + spin_unlock_irq(&kcs_bmc_serio_instances_lock); + + if (!priv) + return -ENODEV; + + /* kfree()s priv->port via put_device() */ + serio_unregister_port(priv->port); + + /* Ensure the IBF IRQ is disabled if we were the active client */ + kcs_bmc_disable_device(kcs_bmc, &priv->client); + + devm_kfree(priv->client.dev->dev, priv); + + return 0; +} + +static const struct kcs_bmc_driver_ops kcs_bmc_serio_driver_ops = { + .add_device = kcs_bmc_serio_add_device, + .remove_device = kcs_bmc_serio_remove_device, +}; + +static struct kcs_bmc_driver kcs_bmc_serio_driver = { + .ops = &kcs_bmc_serio_driver_ops, +}; + +static int kcs_bmc_serio_init(void) +{ + kcs_bmc_register_driver(&kcs_bmc_serio_driver); + + return 0; +} +module_init(kcs_bmc_serio_init); + +static void kcs_bmc_serio_exit(void) +{ + kcs_bmc_unregister_driver(&kcs_bmc_serio_driver); +} +module_exit(kcs_bmc_serio_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Andrew Jeffery "); +MODULE_DESCRIPTION("Adapter driver for serio access to BMC KCS devices");