1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2015-2018, Intel Corporation.
  4 * Copyright (c) 2021, IBM Corp.
  5 */
  6
  7#include <linux/device.h>
  8#include <linux/list.h>
  9#include <linux/module.h>
 10#include <linux/mutex.h>
 11
 12#include "kcs_bmc.h"
 13
 14/* Implement both the device and client interfaces here */
 15#include "kcs_bmc_device.h"
 16#include "kcs_bmc_client.h"
 17
 18/* Record registered devices and drivers */
 19static DEFINE_MUTEX(kcs_bmc_lock);
 20static LIST_HEAD(kcs_bmc_devices);
 21static LIST_HEAD(kcs_bmc_drivers);
 22
 23/* Consumer data access */
 24
 25u8 kcs_bmc_read_data(struct kcs_bmc_device *kcs_bmc)
 26{
 27	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.idr);
 28}
 29EXPORT_SYMBOL(kcs_bmc_read_data);
 30
 31void kcs_bmc_write_data(struct kcs_bmc_device *kcs_bmc, u8 data)
 32{
 33	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.odr, data);
 34}
 35EXPORT_SYMBOL(kcs_bmc_write_data);
 36
 37u8 kcs_bmc_read_status(struct kcs_bmc_device *kcs_bmc)
 38{
 39	return kcs_bmc->ops->io_inputb(kcs_bmc, kcs_bmc->ioreg.str);
 40}
 41EXPORT_SYMBOL(kcs_bmc_read_status);
 42
 43void kcs_bmc_write_status(struct kcs_bmc_device *kcs_bmc, u8 data)
 44{
 45	kcs_bmc->ops->io_outputb(kcs_bmc, kcs_bmc->ioreg.str, data);
 46}
 47EXPORT_SYMBOL(kcs_bmc_write_status);
 48
 49void kcs_bmc_update_status(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 val)
 50{
 51	kcs_bmc->ops->io_updateb(kcs_bmc, kcs_bmc->ioreg.str, mask, val);
 52}
 53EXPORT_SYMBOL(kcs_bmc_update_status);
 54
 55irqreturn_t kcs_bmc_handle_event(struct kcs_bmc_device *kcs_bmc)
 56{
 57	struct kcs_bmc_client *client;
 58	irqreturn_t rc = IRQ_NONE;
 59	unsigned long flags;
 60
 61	spin_lock_irqsave(&kcs_bmc->lock, flags);
 62	client = kcs_bmc->client;
 63	if (client)
 64		rc = client->ops->event(client);
 65	spin_unlock_irqrestore(&kcs_bmc->lock, flags);
 66
 67	return rc;
 68}
 69EXPORT_SYMBOL(kcs_bmc_handle_event);
 70
 71int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
 72{
 73	int rc;
 74
 75	spin_lock_irq(&kcs_bmc->lock);
 76	if (kcs_bmc->client) {
 77		rc = -EBUSY;
 78	} else {
 79		u8 mask = KCS_BMC_EVENT_TYPE_IBF;
 80
 81		kcs_bmc->client = client;
 82		kcs_bmc_update_event_mask(kcs_bmc, mask, mask);
 83		rc = 0;
 84	}
 85	spin_unlock_irq(&kcs_bmc->lock);
 86
 87	return rc;
 88}
 89EXPORT_SYMBOL(kcs_bmc_enable_device);
 90
 91void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
 92{
 93	spin_lock_irq(&kcs_bmc->lock);
 94	if (client == kcs_bmc->client) {
 95		u8 mask = KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE;
 96
 97		kcs_bmc_update_event_mask(kcs_bmc, mask, 0);
 98		kcs_bmc->client = NULL;
 99	}
100	spin_unlock_irq(&kcs_bmc->lock);
101}
102EXPORT_SYMBOL(kcs_bmc_disable_device);
103
104int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc)
105{
106	struct kcs_bmc_driver *drv;
107	int error = 0;
108	int rc;
109
110	spin_lock_init(&kcs_bmc->lock);
111	kcs_bmc->client = NULL;
112
113	mutex_lock(&kcs_bmc_lock);
114	list_add(&kcs_bmc->entry, &kcs_bmc_devices);
115	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
116		rc = drv->ops->add_device(kcs_bmc);
117		if (!rc)
118			continue;
119
120		dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
121			kcs_bmc->channel, rc);
122		error = rc;
123	}
124	mutex_unlock(&kcs_bmc_lock);
125
126	return error;
127}
128EXPORT_SYMBOL(kcs_bmc_add_device);
129
130void kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc)
131{
132	struct kcs_bmc_driver *drv;
133	int rc;
134
135	mutex_lock(&kcs_bmc_lock);
136	list_del(&kcs_bmc->entry);
137	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
138		rc = drv->ops->remove_device(kcs_bmc);
139		if (rc)
140			dev_err(kcs_bmc->dev, "Failed to remove chardev for KCS channel %d: %d",
141				kcs_bmc->channel, rc);
142	}
143	mutex_unlock(&kcs_bmc_lock);
144}
145EXPORT_SYMBOL(kcs_bmc_remove_device);
146
147void kcs_bmc_register_driver(struct kcs_bmc_driver *drv)
148{
149	struct kcs_bmc_device *kcs_bmc;
150	int rc;
151
152	mutex_lock(&kcs_bmc_lock);
153	list_add(&drv->entry, &kcs_bmc_drivers);
154	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
155		rc = drv->ops->add_device(kcs_bmc);
156		if (rc)
157			dev_err(kcs_bmc->dev, "Failed to add driver for KCS channel %d: %d",
158				kcs_bmc->channel, rc);
159	}
160	mutex_unlock(&kcs_bmc_lock);
161}
162EXPORT_SYMBOL(kcs_bmc_register_driver);
163
164void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv)
165{
166	struct kcs_bmc_device *kcs_bmc;
167	int rc;
168
169	mutex_lock(&kcs_bmc_lock);
170	list_del(&drv->entry);
171	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
172		rc = drv->ops->remove_device(kcs_bmc);
173		if (rc)
174			dev_err(kcs_bmc->dev, "Failed to remove driver for KCS channel %d: %d",
175				kcs_bmc->channel, rc);
176	}
177	mutex_unlock(&kcs_bmc_lock);
178}
179EXPORT_SYMBOL(kcs_bmc_unregister_driver);
180
181void kcs_bmc_update_event_mask(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 events)
182{
183	kcs_bmc->ops->irq_mask_update(kcs_bmc, mask, events);
184}
185EXPORT_SYMBOL(kcs_bmc_update_event_mask);
186
187MODULE_LICENSE("GPL v2");
188MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
189MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
190MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");