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         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 }
  69 EXPORT_SYMBOL(kcs_bmc_handle_event);
  70
  71 int 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 }
  89 EXPORT_SYMBOL(kcs_bmc_enable_device);
  90
  91 void 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 }
 102 EXPORT_SYMBOL(kcs_bmc_disable_device);
 103
 104 int 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 }
 128 EXPORT_SYMBOL(kcs_bmc_add_device);
 129
 130 void 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 }
 145 EXPORT_SYMBOL(kcs_bmc_remove_device);
 146
 147 void 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 }
 162 EXPORT_SYMBOL(kcs_bmc_register_driver);
 163
 164 void 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 }
 179 EXPORT_SYMBOL(kcs_bmc_unregister_driver);
 180
 181 void 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 }
 185 EXPORT_SYMBOL(kcs_bmc_update_event_mask);
 186
 187 MODULE_LICENSE("GPL v2");
 188 MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
 189 MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
 190 MODULE_DESCRIPTION("KCS BMC to handle the IPMI request from system software");