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 struct attribute *m10bmc_attrs[] = {
  64         &dev_attr_bmc_version.attr,
  65         &dev_attr_bmcfw_version.attr,
  66         NULL,
  67 };
  68 ATTRIBUTE_GROUPS(m10bmc);
  69
  70 static int check_m10bmc_version(struct intel_m10bmc *ddata)
  71 {
  72         unsigned int v;
  73         int ret;
  74
  75         /*
  76          * This check is to filter out the very old legacy BMC versions,
  77          * M10BMC_LEGACY_SYS_BASE is the offset to this old block of mmio
  78          * registers. In the old BMC chips, the BMC version info is stored
  79          * in this old version register (M10BMC_LEGACY_SYS_BASE +
  80          * M10BMC_BUILD_VER), so its read out value would have not been
  81          * LEGACY_INVALID (0xffffffff). But in new BMC chips that the
  82          * driver supports, the value of this register should be
  83          * LEGACY_INVALID.
  84          */
  85         ret = m10bmc_raw_read(ddata,
  86                               M10BMC_LEGACY_SYS_BASE + M10BMC_BUILD_VER, &v);
  87         if (ret)
  88                 return -ENODEV;
  89
  90         if (v != M10BMC_VER_LEGACY_INVALID) {
  91                 dev_err(ddata->dev, "bad version M10BMC detected\n");
  92                 return -ENODEV;
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int intel_m10_bmc_spi_probe(struct spi_device *spi)
  99 {
 100         const struct spi_device_id *id = spi_get_device_id(spi);
 101         struct device *dev = &spi->dev;
 102         struct mfd_cell *cells;
 103         struct intel_m10bmc *ddata;
 104         int ret, n_cell;
 105
 106         ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 107         if (!ddata)
 108                 return -ENOMEM;
 109
 110         ddata->dev = dev;
 111
 112         ddata->regmap =
 113                 devm_regmap_init_spi_avmm(spi, &intel_m10bmc_regmap_config);
 114         if (IS_ERR(ddata->regmap)) {
 115                 ret = PTR_ERR(ddata->regmap);
 116                 dev_err(dev, "Failed to allocate regmap: %d\n", ret);
 117                 return ret;
 118         }
 119
 120         spi_set_drvdata(spi, ddata);
 121
 122         ret = check_m10bmc_version(ddata);
 123         if (ret) {
 124                 dev_err(dev, "Failed to identify m10bmc hardware\n");
 125                 return ret;
 126         }
 127
 128         switch (id->driver_data) {
 129         case M10_N3000:
 130                 cells = m10bmc_pacn3000_subdevs;
 131                 n_cell = ARRAY_SIZE(m10bmc_pacn3000_subdevs);
 132                 break;
 133         default:
 134                 return -ENODEV;
 135         }
 136
 137         ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, n_cell,
 138                                    NULL, 0, NULL);
 139         if (ret)
 140                 dev_err(dev, "Failed to register sub-devices: %d\n", ret);
 141
 142         return ret;
 143 }
 144
 145 static const struct spi_device_id m10bmc_spi_id[] = {
 146         { "m10-n3000", M10_N3000 },
 147         { }
 148 };
 149 MODULE_DEVICE_TABLE(spi, m10bmc_spi_id);
 150
 151 static struct spi_driver intel_m10bmc_spi_driver = {
 152         .driver = {
 153                 .name = "intel-m10-bmc",
 154                 .dev_groups = m10bmc_groups,
 155         },
 156         .probe = intel_m10_bmc_spi_probe,
 157         .id_table = m10bmc_spi_id,
 158 };
 159 module_spi_driver(intel_m10bmc_spi_driver);
 160
 161 MODULE_DESCRIPTION("Intel MAX 10 BMC Device Driver");
 162 MODULE_AUTHOR("Intel Corporation");
 163 MODULE_LICENSE("GPL v2");
 164 MODULE_ALIAS("spi:intel-m10-bmc");