drivers/mfd/intel-m10-bmc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Intel MAX 10 Board Management Controller chip
   4  *
   5  * Copyright (C) 2018-2020 Intel Corporation. All rights reserved.
   6  */
   7 #include <linux/bitfield.h>
   8 #include <linux/init.h>
   9 #include <linux/mfd/core.h>
  10 #include <linux/mfd/intel-m10-bmc.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/regmap.h>
  14 #include <linux/spi/spi.h>
  15
  16 enum m10bmc_type {
  17         M10_N3000,
  18 };
  19
  20 static struct mfd_cell m10bmc_pacn3000_subdevs[] = {
  21         { .name = "n3000bmc-hwmon" },
  22         { .name = "n3000bmc-retimer" },
  23         { .name = "n3000bmc-secure" },
  24 };
  25
  26 static struct regmap_config intel_m10bmc_regmap_config = {
  27         .reg_bits = 32,
  28         .val_bits = 32,
  29         .reg_stride = 4,
  30         .max_register = M10BMC_MEM_END,
  31 };
  32
  33 static ssize_t bmc_version_show(struct device *dev,
  34                                 struct device_attribute *attr, char *buf)
  35 {
  36         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
  37         unsigned int val;
  38         int ret;
  39
  40         ret = m10bmc_sys_read(ddata, M10BMC_BUILD_VER, &val);
  41         if (ret)
  42                 return ret;
  43
  44         return sprintf(buf, "0x%x\n", val);
  45 }
  46 static DEVICE_ATTR_RO(bmc_version);
  47
  48 static ssize_t bmcfw_version_show(struct device *dev,
  49                                   struct device_attribute *attr, char *buf)
  50 {
  51         struct intel_m10bmc *ddata = dev_get_drvdata(dev);
  52         unsigned int val;
  53         int ret;
  54
  55         ret = m10bmc_sys_read(ddata, NIOS2_FW_VERSION, &val);
  56         if (ret)
  57                 return ret;
  58
  59         return sprintf(buf, "0x%x\n", val);
  60 }
  61 static DEVICE_ATTR_RO(bmcfw_version);
  62
  63 static ssize_t mac_address_show(struct device *dev,
  64                                 struct device_attribute *attr, char *buf)
  65 {
  66         struct intel_m10bmc *max10 = dev_get_drvdata(dev);
  67         unsigned int macaddr_low, macaddr_high;
  68         int ret;
  69
  70         ret = m10bmc_sys_read(max10, M10BMC_MAC_LOW, &macaddr_low);
  71         if (ret)
  72                 return ret;
  73
  74         ret = m10bmc_sys_read(max10, M10BMC_MAC_HIGH, &macaddr_high);
  75         if (ret)
  76                 return ret;
  77
  78         return sysfs_emit(buf, "%02x:%02x:%02x:%02x:%02x:%02x\n",
  79                           (u8)FIELD_GET(M10BMC_MAC_BYTE1, macaddr_low),
  80                           (u8)FIELD_GET(M10BMC_MAC_BYTE2, macaddr_low),
  81                           (u8)FIELD_GET(M10BMC_MAC_BYTE3, macaddr_low),
  82                           (u8)FIELD_GET(M10BMC_MAC_BYTE4, macaddr_low),
  83                           (u8)FIELD_GET(M10BMC_MAC_BYTE5, macaddr_high),
  84                           (u8)FIELD_GET(M10BMC_MAC_BYTE6, macaddr_high));
  85 }
  86 static DEVICE_ATTR_RO(mac_address);
  87
  88 static ssize_t mac_count_show(struct device *dev,
  89                               struct device_attribute *attr, char *buf)
  90 {
  91         struct intel_m10bmc *max10 = dev_get_drvdata(dev);
  92         unsigned int macaddr_high;
  93         int ret;
  94
  95         ret = m10bmc_sys_read(max10, M10BMC_MAC_HIGH, &macaddr_high);
  96         if (ret)
  97                 return ret;
  98
  99         return sysfs_emit(buf, "%u\n",
 100                           (u8)FIELD_GET(M10BMC_MAC_COUNT, macaddr_high));
 101 }
 102 static DEVICE_ATTR_RO(mac_count);
 103
 104 static struct attribute *m10bmc_attrs[] = {
 105         &dev_attr_bmc_version.attr,
 106         &dev_attr_bmcfw_version.attr,
 107         &dev_attr_mac_address.attr,
 108         &dev_attr_mac_count.attr,
 109         NULL,
 110 };
 111 ATTRIBUTE_GROUPS(m10bmc);
 112
 113 static int check_m10bmc_version(struct intel_m10bmc *ddata)
 114 {
 115         unsigned int v;
 116         int ret;
 117
 118         /*
 119          * This check is to filter out the very old legacy BMC versions,
 120          * M10BMC_LEGACY_SYS_BASE is the offset to this old block of mmio
 121          * registers. In the old BMC chips, the BMC version info is stored
 122          * in this old version register (M10BMC_LEGACY_SYS_BASE +
 123          * M10BMC_BUILD_VER), so its read out value would have not been
 124          * LEGACY_INVALID (0xffffffff). But in new BMC chips that the
 125          * driver supports, the value of this register should be
 126          * LEGACY_INVALID.
 127          */
 128         ret = m10bmc_raw_read(ddata,
 129                               M10BMC_LEGACY_SYS_BASE + M10BMC_BUILD_VER, &v);
 130         if (ret)
 131                 return -ENODEV;
 132
 133         if (v != M10BMC_VER_LEGACY_INVALID) {
 134                 dev_err(ddata->dev, "bad version M10BMC detected\n");
 135                 return -ENODEV;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int intel_m10_bmc_spi_probe(struct spi_device *spi)
 142 {
 143         const struct spi_device_id *id = spi_get_device_id(spi);
 144         struct device *dev = &spi->dev;
 145         struct mfd_cell *cells;
 146         struct intel_m10bmc *ddata;
 147         int ret, n_cell;
 148
 149         ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 150         if (!ddata)
 151                 return -ENOMEM;
 152
 153         ddata->dev = dev;
 154
 155         ddata->regmap =
 156                 devm_regmap_init_spi_avmm(spi, &intel_m10bmc_regmap_config);
 157         if (IS_ERR(ddata->regmap)) {
 158                 ret = PTR_ERR(ddata->regmap);
 159                 dev_err(dev, "Failed to allocate regmap: %d\n", ret);
 160                 return ret;
 161         }
 162
 163         spi_set_drvdata(spi, ddata);
 164
 165         ret = check_m10bmc_version(ddata);
 166         if (ret) {
 167                 dev_err(dev, "Failed to identify m10bmc hardware\n");
 168                 return ret;
 169         }
 170
 171         switch (id->driver_data) {
 172         case M10_N3000:
 173                 cells = m10bmc_pacn3000_subdevs;
 174                 n_cell = ARRAY_SIZE(m10bmc_pacn3000_subdevs);
 175                 break;
 176         default:
 177                 return -ENODEV;
 178         }
 179
 180         ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, n_cell,
 181                                    NULL, 0, NULL);
 182         if (ret)
 183                 dev_err(dev, "Failed to register sub-devices: %d\n", ret);
 184
 185         return ret;
 186 }
 187
 188 static const struct spi_device_id m10bmc_spi_id[] = {
 189         { "m10-n3000", M10_N3000 },
 190         { }
 191 };
 192 MODULE_DEVICE_TABLE(spi, m10bmc_spi_id);
 193
 194 static struct spi_driver intel_m10bmc_spi_driver = {
 195         .driver = {
 196                 .name = "intel-m10-bmc",
 197                 .dev_groups = m10bmc_groups,
 198         },
 199         .probe = intel_m10_bmc_spi_probe,
 200         .id_table = m10bmc_spi_id,
 201 };
 202 module_spi_driver(intel_m10bmc_spi_driver);
 203
 204 MODULE_DESCRIPTION("Intel MAX 10 BMC Device Driver");
 205 MODULE_AUTHOR("Intel Corporation");
 206 MODULE_LICENSE("GPL v2");
 207 MODULE_ALIAS("spi:intel-m10-bmc");