xref: /openbmc/linux/drivers/char/ipmi/kcs_bmc.c (revision 2a598d0b)
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 */
19 static DEFINE_MUTEX(kcs_bmc_lock);
20 static LIST_HEAD(kcs_bmc_devices);
21 static LIST_HEAD(kcs_bmc_drivers);
22 
23 /* Consumer data access */
24 
25 u8 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 }
29 EXPORT_SYMBOL(kcs_bmc_read_data);
30 
31 void 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 }
35 EXPORT_SYMBOL(kcs_bmc_write_data);
36 
37 u8 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 }
41 EXPORT_SYMBOL(kcs_bmc_read_status);
42 
43 void 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 }
47 EXPORT_SYMBOL(kcs_bmc_write_status);
48 
49 void 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 }
53 EXPORT_SYMBOL(kcs_bmc_update_status);
54 
55 irqreturn_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 
60 	spin_lock(&kcs_bmc->lock);
61 	client = kcs_bmc->client;
62 	if (client)
63 		rc = client->ops->event(client);
64 	spin_unlock(&kcs_bmc->lock);
65 
66 	return rc;
67 }
68 EXPORT_SYMBOL(kcs_bmc_handle_event);
69 
70 int kcs_bmc_enable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
71 {
72 	int rc;
73 
74 	spin_lock_irq(&kcs_bmc->lock);
75 	if (kcs_bmc->client) {
76 		rc = -EBUSY;
77 	} else {
78 		u8 mask = KCS_BMC_EVENT_TYPE_IBF;
79 
80 		kcs_bmc->client = client;
81 		kcs_bmc_update_event_mask(kcs_bmc, mask, mask);
82 		rc = 0;
83 	}
84 	spin_unlock_irq(&kcs_bmc->lock);
85 
86 	return rc;
87 }
88 EXPORT_SYMBOL(kcs_bmc_enable_device);
89 
90 void kcs_bmc_disable_device(struct kcs_bmc_device *kcs_bmc, struct kcs_bmc_client *client)
91 {
92 	spin_lock_irq(&kcs_bmc->lock);
93 	if (client == kcs_bmc->client) {
94 		u8 mask = KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE;
95 
96 		kcs_bmc_update_event_mask(kcs_bmc, mask, 0);
97 		kcs_bmc->client = NULL;
98 	}
99 	spin_unlock_irq(&kcs_bmc->lock);
100 }
101 EXPORT_SYMBOL(kcs_bmc_disable_device);
102 
103 int kcs_bmc_add_device(struct kcs_bmc_device *kcs_bmc)
104 {
105 	struct kcs_bmc_driver *drv;
106 	int error = 0;
107 	int rc;
108 
109 	spin_lock_init(&kcs_bmc->lock);
110 	kcs_bmc->client = NULL;
111 
112 	mutex_lock(&kcs_bmc_lock);
113 	list_add(&kcs_bmc->entry, &kcs_bmc_devices);
114 	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
115 		rc = drv->ops->add_device(kcs_bmc);
116 		if (!rc)
117 			continue;
118 
119 		dev_err(kcs_bmc->dev, "Failed to add chardev for KCS channel %d: %d",
120 			kcs_bmc->channel, rc);
121 		error = rc;
122 	}
123 	mutex_unlock(&kcs_bmc_lock);
124 
125 	return error;
126 }
127 EXPORT_SYMBOL(kcs_bmc_add_device);
128 
129 void kcs_bmc_remove_device(struct kcs_bmc_device *kcs_bmc)
130 {
131 	struct kcs_bmc_driver *drv;
132 	int rc;
133 
134 	mutex_lock(&kcs_bmc_lock);
135 	list_del(&kcs_bmc->entry);
136 	list_for_each_entry(drv, &kcs_bmc_drivers, entry) {
137 		rc = drv->ops->remove_device(kcs_bmc);
138 		if (rc)
139 			dev_err(kcs_bmc->dev, "Failed to remove chardev for KCS channel %d: %d",
140 				kcs_bmc->channel, rc);
141 	}
142 	mutex_unlock(&kcs_bmc_lock);
143 }
144 EXPORT_SYMBOL(kcs_bmc_remove_device);
145 
146 void kcs_bmc_register_driver(struct kcs_bmc_driver *drv)
147 {
148 	struct kcs_bmc_device *kcs_bmc;
149 	int rc;
150 
151 	mutex_lock(&kcs_bmc_lock);
152 	list_add(&drv->entry, &kcs_bmc_drivers);
153 	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
154 		rc = drv->ops->add_device(kcs_bmc);
155 		if (rc)
156 			dev_err(kcs_bmc->dev, "Failed to add driver for KCS channel %d: %d",
157 				kcs_bmc->channel, rc);
158 	}
159 	mutex_unlock(&kcs_bmc_lock);
160 }
161 EXPORT_SYMBOL(kcs_bmc_register_driver);
162 
163 void kcs_bmc_unregister_driver(struct kcs_bmc_driver *drv)
164 {
165 	struct kcs_bmc_device *kcs_bmc;
166 	int rc;
167 
168 	mutex_lock(&kcs_bmc_lock);
169 	list_del(&drv->entry);
170 	list_for_each_entry(kcs_bmc, &kcs_bmc_devices, entry) {
171 		rc = drv->ops->remove_device(kcs_bmc);
172 		if (rc)
173 			dev_err(kcs_bmc->dev, "Failed to remove driver for KCS channel %d: %d",
174 				kcs_bmc->channel, rc);
175 	}
176 	mutex_unlock(&kcs_bmc_lock);
177 }
178 EXPORT_SYMBOL(kcs_bmc_unregister_driver);
179 
180 void kcs_bmc_update_event_mask(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 events)
181 {
182 	kcs_bmc->ops->irq_mask_update(kcs_bmc, mask, events);
183 }
184 EXPORT_SYMBOL(kcs_bmc_update_event_mask);
185 
186 MODULE_LICENSE("GPL v2");
187 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
188 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
189 MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");
190