drivers/char/ipmi/kcs_bmc.c

   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");