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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Hardware monitoring driver for Maxim MAX15301 * * Copyright (c) 2021 Flextronics International Sweden AB * * Even though the specification does not specifically mention it, * extensive empirical testing has revealed that auto-detection of * limit-registers will fail in a random fashion unless the delay * parameter is set to above about 80us. The default delay is set * to 100us to include some safety margin. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/err.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/ktime.h> #include <linux/delay.h> #include <linux/pmbus.h> #include "pmbus.h" static const struct i2c_device_id max15301_id[] = { {"bmr461", 0}, {"max15301", 0}, {} }; MODULE_DEVICE_TABLE(i2c, max15301_id); struct max15301_data { int id; ktime_t access; /* Chip access time */ int delay; /* Delay between chip accesses in us */ struct pmbus_driver_info info; }; #define to_max15301_data(x) container_of(x, struct max15301_data, info) #define MAX15301_WAIT_TIME 100 /* us */ static ushort delay = MAX15301_WAIT_TIME; module_param(delay, ushort, 0644); MODULE_PARM_DESC(delay, "Delay between chip accesses in us"); static struct max15301_data max15301_data = { .info = { .pages = 1, .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT, } }; /* This chip needs a delay between accesses */ static inline void max15301_wait(const struct max15301_data *data) { if (data->delay) { s64 delta = ktime_us_delta(ktime_get(), data->access); if (delta < data->delay) udelay(data->delay - delta); } } static int max15301_read_word_data(struct i2c_client *client, int page, int phase, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max15301_data *data = to_max15301_data(info); int ret; if (page > 0) return -ENXIO; if (reg >= PMBUS_VIRT_BASE) return -ENXIO; max15301_wait(data); ret = pmbus_read_word_data(client, page, phase, reg); data->access = ktime_get(); return ret; } static int max15301_read_byte_data(struct i2c_client *client, int page, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max15301_data *data = to_max15301_data(info); int ret; if (page > 0) return -ENXIO; max15301_wait(data); ret = pmbus_read_byte_data(client, page, reg); data->access = ktime_get(); return ret; } static int max15301_write_word_data(struct i2c_client *client, int page, int reg, u16 word) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max15301_data *data = to_max15301_data(info); int ret; if (page > 0) return -ENXIO; if (reg >= PMBUS_VIRT_BASE) return -ENXIO; max15301_wait(data); ret = pmbus_write_word_data(client, page, reg, word); data->access = ktime_get(); return ret; } static int max15301_write_byte(struct i2c_client *client, int page, u8 value) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max15301_data *data = to_max15301_data(info); int ret; if (page > 0) return -ENXIO; max15301_wait(data); ret = pmbus_write_byte(client, page, value); data->access = ktime_get(); return ret; } static int max15301_probe(struct i2c_client *client) { int status; u8 device_id[I2C_SMBUS_BLOCK_MAX + 1]; const struct i2c_device_id *mid; struct pmbus_driver_info *info = &max15301_data.info; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_BLOCK_DATA)) return -ENODEV; status = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, device_id); if (status < 0) { dev_err(&client->dev, "Failed to read Device Id\n"); return status; } for (mid = max15301_id; mid->name[0]; mid++) { if (!strncasecmp(mid->name, device_id, strlen(mid->name))) break; } if (!mid->name[0]) { dev_err(&client->dev, "Unsupported device\n"); return -ENODEV; } max15301_data.delay = delay; info->read_byte_data = max15301_read_byte_data; info->read_word_data = max15301_read_word_data; info->write_byte = max15301_write_byte; info->write_word_data = max15301_write_word_data; return pmbus_do_probe(client, info); } static struct i2c_driver max15301_driver = { .driver = { .name = "max15301", }, .probe = max15301_probe, .id_table = max15301_id, }; module_i2c_driver(max15301_driver); MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>"); MODULE_DESCRIPTION("PMBus driver for Maxim MAX15301"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS(PMBUS); |