drivers/mfd/intel-m10-bmc-core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Intel MAX 10 Board Management Controller chip - common code
   4  *
   5  * Copyright (C) 2018-2020 Intel Corporation. All rights reserved.
   6  */
   7
   8 #include <linux/bitfield.h>
   9 #include <linux/device.h>
  10 #include <linux/dev_printk.h>
  11 #include <linux/mfd/core.h>
  12 #include <linux/mfd/intel-m10-bmc.h>
  13 #include <linux/module.h>
  14
  15 void m10bmc_fw_state_set(struct intel_m10bmc *m10bmc, enum m10bmc_fw_state new_state)
  16 {
  17         /* bmcfw_state is only needed if handshake_sys_reg_nranges > 0 */
  18         if (!m10bmc->info->handshake_sys_reg_nranges)
  19                 return;
  20
  21         down_write(&m10bmc->bmcfw_lock);
  22         m10bmc->bmcfw_state = new_state;
  23         up_write(&m10bmc->bmcfw_lock);
  24 }
  25 EXPORT_SYMBOL_NS_GPL(m10bmc_fw_state_set, INTEL_M10_BMC_CORE);
  26
  27 /*
  28  * For some Intel FPGA devices, the BMC firmware is not available to service
  29  * handshake registers during a secure update.
  30  */
  31 static bool m10bmc_reg_always_available(struct intel_m10bmc *m10bmc, unsigned int offset)
  32 {
  33         if (!m10bmc->info->handshake_sys_reg_nranges)
  34                 return true;
  35
  36         return !regmap_reg_in_ranges(offset, m10bmc->info->handshake_sys_reg_ranges,
  37                                      m10bmc->info->handshake_sys_reg_nranges);
  38 }
  39
  40 /*
  41  * m10bmc_handshake_reg_unavailable - Checks if reg access collides with secure update state
  42  * @m10bmc: M10 BMC structure
  43  *
  44  * For some Intel FPGA devices, the BMC firmware is not available to service
  45  * handshake registers during a secure update erase and write phases.
  46  *
  47  * Context: @m10bmc->bmcfw_lock must be held.
  48  */
  49 static bool m10bmc_handshake_reg_unavailable(struct intel_m10bmc *m10bmc)
  50 {
  51         return m10bmc->bmcfw_state == M10BMC_FW_STATE_SEC_UPDATE_PREPARE ||
  52                m10bmc->bmcfw_state == M10BMC_FW_STATE_SEC_UPDATE_WRITE;
  53 }
  54
  55 /*
  56  * This function helps to simplify the accessing of the system registers.
  57  *
  58  * The base of the system registers is configured through the struct
  59  * csr_map.
  60  */
  61 int m10bmc_sys_read(struct intel_m10bmc *m10bmc, unsigned int offset, unsigned int *val)
  62 {
  63         const struct m10bmc_csr_map *csr_map = m10bmc->info->csr_map;
  64         int ret;
  65
  66         if (m10bmc_reg_always_available(m10bmc, offset))
  67                 return m10bmc_raw_read(m10bmc, csr_map->base + offset, val);
  68
  69         down_read(&m10bmc->bmcfw_lock);
  70         if (m10bmc_handshake_reg_unavailable(m10bmc))
  71                 ret = -EBUSY;   /* Reg not available during secure update */
  72         else
  73                 ret = m10bmc_raw_read(m10bmc, csr_map->base + offset, val);
  74         up_read(&m10bmc->bmcfw_lock);
  75
  76         return ret;
  77 }
  78 EXPORT_SYMBOL_NS_GPL(m10bmc_sys_read, INTEL_M10_BMC_CORE);
  79
  80 int m10bmc_sys_update_bits(struct intel_m10bmc *m10bmc, unsigned int offset,
  81                            unsigned int msk, unsigned int val)
  82 {
  83         const struct m10bmc_csr_map *csr_map = m10bmc->info->csr_map;
  84         int ret;
  85
  86         if (m10bmc_reg_always_available(m10bmc, offset))
  87                 return regmap_update_bits(m10bmc->regmap, csr_map->base + offset, msk, val);
  88
  89         down_read(&m10bmc->bmcfw_lock);
  90         if (m10bmc_handshake_reg_unavailable(m10bmc))
  91                 ret = -EBUSY;   /* Reg not available during secure update */
  92         else
  93                 ret = regmap_update_bits(m10bmc->regmap, csr_map->base + offset, msk, val);
  94         up_read(&m10bmc->bmcfw_lock);
  95
  96         return ret;
  97 }
  98 EXPORT_SYMBOL_NS_GPL(m10bmc_sys_update_bits, INTEL_M10_BMC_CORE);
  99
 100 static ssize_t bmc_version_show(struct device *dev,
 101                                 struct device_attribute *attr, char *buf)
 102 {
 103         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
 104         unsigned int val;
 105         int ret;
 106
 107         ret = m10bmc_sys_read(ddata, ddata->info->csr_map->build_version, &val);
 108         if (ret)
 109                 return ret;
 110
 111         return sprintf(buf, "0x%x\n", val);
 112 }
 113 static DEVICE_ATTR_RO(bmc_version);
 114
 115 static ssize_t bmcfw_version_show(struct device *dev,
 116                                   struct device_attribute *attr, char *buf)
 117 {
 118         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
 119         unsigned int val;
 120         int ret;
 121
 122         ret = m10bmc_sys_read(ddata, ddata->info->csr_map->fw_version, &val);
 123         if (ret)
 124                 return ret;
 125
 126         return sprintf(buf, "0x%x\n", val);
 127 }
 128 static DEVICE_ATTR_RO(bmcfw_version);
 129
 130 static ssize_t mac_address_show(struct device *dev,
 131                                 struct device_attribute *attr, char *buf)
 132 {
 133         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
 134         unsigned int macaddr_low, macaddr_high;
 135         int ret;
 136
 137         ret = m10bmc_sys_read(ddata, ddata->info->csr_map->mac_low, &macaddr_low);
 138         if (ret)
 139                 return ret;
 140
 141         ret = m10bmc_sys_read(ddata, ddata->info->csr_map->mac_high, &macaddr_high);
 142         if (ret)
 143                 return ret;
 144
 145         return sysfs_emit(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
 146                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE1, macaddr_low),
 147                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE2, macaddr_low),
 148                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE3, macaddr_low),
 149                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE4, macaddr_low),
 150                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE5, macaddr_high),
 151                           (u8)FIELD_GET(M10BMC_N3000_MAC_BYTE6, macaddr_high));
 152 }
 153 static DEVICE_ATTR_RO(mac_address);
 154
 155 static ssize_t mac_count_show(struct device *dev,
 156                               struct device_attribute *attr, char *buf)
 157 {
 158         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
 159         unsigned int macaddr_high;
 160         int ret;
 161
 162         ret = m10bmc_sys_read(ddata, ddata->info->csr_map->mac_high, &macaddr_high);
 163         if (ret)
 164                 return ret;
 165
 166         return sysfs_emit(buf, "%u\n", (u8)FIELD_GET(M10BMC_N3000_MAC_COUNT, macaddr_high));
 167 }
 168 static DEVICE_ATTR_RO(mac_count);
 169
 170 static struct attribute *m10bmc_attrs[] = {
 171         &dev_attr_bmc_version.attr,
 172         &dev_attr_bmcfw_version.attr,
 173         &dev_attr_mac_address.attr,
 174         &dev_attr_mac_count.attr,
 175         NULL,
 176 };
 177
 178 static const struct attribute_group m10bmc_group = {
 179         .attrs = m10bmc_attrs,
 180 };
 181
 182 const struct attribute_group *m10bmc_dev_groups[] = {
 183         &m10bmc_group,
 184         NULL,
 185 };
 186 EXPORT_SYMBOL_NS_GPL(m10bmc_dev_groups, INTEL_M10_BMC_CORE);
 187
 188 int m10bmc_dev_init(struct intel_m10bmc *m10bmc, const struct intel_m10bmc_platform_info *info)
 189 {
 190         int ret;
 191
 192         m10bmc->info = info;
 193         dev_set_drvdata(m10bmc->dev, m10bmc);
 194         init_rwsem(&m10bmc->bmcfw_lock);
 195
 196         ret = devm_mfd_add_devices(m10bmc->dev, PLATFORM_DEVID_AUTO,
 197                                    info->cells, info->n_cells,
 198                                    NULL, 0, NULL);
 199         if (ret)
 200                 dev_err(m10bmc->dev, "Failed to register sub-devices: %d\n", ret);
 201
 202         return ret;
 203 }
 204 EXPORT_SYMBOL_NS_GPL(m10bmc_dev_init, INTEL_M10_BMC_CORE);
 205
 206 MODULE_DESCRIPTION("Intel MAX 10 BMC core driver");
 207 MODULE_AUTHOR("Intel Corporation");
 208 MODULE_LICENSE("GPL v2");