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
bmc_version_show(struct device * dev,struct device_attribute * attr,char * buf)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
bmcfw_version_show(struct device * dev,struct device_attribute * attr,char * buf)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
check_m10bmc_version(struct intel_m10bmc * ddata)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
intel_m10_bmc_spi_probe(struct spi_device * spi)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");
165
