diff options
Diffstat (limited to 'drivers/hwmon/pmbus/stpddc60.c')
| -rw-r--r-- | drivers/hwmon/pmbus/stpddc60.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/stpddc60.c b/drivers/hwmon/pmbus/stpddc60.c new file mode 100644 index 000000000..357b9d9d8 --- /dev/null +++ b/drivers/hwmon/pmbus/stpddc60.c @@ -0,0 +1,249 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Hardware monitoring driver for the STPDDC60 controller + * + * Copyright (c) 2021 Flextronics International Sweden AB. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/pmbus.h> +#include "pmbus.h" + +#define STPDDC60_MFR_READ_VOUT 0xd2 +#define STPDDC60_MFR_OV_LIMIT_OFFSET 0xe5 +#define STPDDC60_MFR_UV_LIMIT_OFFSET 0xe6 + +static const struct i2c_device_id stpddc60_id[] = { + {"stpddc60", 0}, + {"bmr481", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, stpddc60_id); + +static struct pmbus_driver_info stpddc60_info = { + .pages = 1, + .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT + | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT + | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP + | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT + | PMBUS_HAVE_POUT, +}; + +/* + * Calculate the closest absolute offset between commanded vout value + * and limit value in steps of 50mv in the range 0 (50mv) to 7 (400mv). + * Return 0 if the upper limit is lower than vout or if the lower limit + * is higher than vout. + */ +static u8 stpddc60_get_offset(int vout, u16 limit, bool over) +{ + int offset; + long v, l; + + v = 250 + (vout - 1) * 5; /* Convert VID to mv */ + l = (limit * 1000L) >> 8; /* Convert LINEAR to mv */ + + if (over == (l < v)) + return 0; + + offset = DIV_ROUND_CLOSEST(abs(l - v), 50); + + if (offset > 0) + offset--; + + return clamp_val(offset, 0, 7); +} + +/* + * Adjust the linear format word to use the given fixed exponent. + */ +static u16 stpddc60_adjust_linear(u16 word, s16 fixed) +{ + s16 e, m, d; + + e = ((s16)word) >> 11; + m = ((s16)((word & 0x7ff) << 5)) >> 5; + d = e - fixed; + + if (d >= 0) + m <<= d; + else + m >>= -d; + + return clamp_val(m, 0, 0x3ff) | ((fixed << 11) & 0xf800); +} + +/* + * The VOUT_COMMAND register uses the VID format but the vout alarm limit + * registers use the LINEAR format so we override VOUT_MODE here to force + * LINEAR format for all registers. + */ +static int stpddc60_read_byte_data(struct i2c_client *client, int page, int reg) +{ + int ret; + + if (page > 0) + return -ENXIO; + + switch (reg) { + case PMBUS_VOUT_MODE: + ret = 0x18; + break; + default: + ret = -ENODATA; + break; + } + + return ret; +} + +/* + * The vout related registers return values in LINEAR11 format when LINEAR16 + * is expected. Clear the top 5 bits to set the exponent part to zero to + * convert the value to LINEAR16 format. + */ +static int stpddc60_read_word_data(struct i2c_client *client, int page, + int phase, int reg) +{ + int ret; + + if (page > 0) + return -ENXIO; + + switch (reg) { + case PMBUS_READ_VOUT: + ret = pmbus_read_word_data(client, page, phase, + STPDDC60_MFR_READ_VOUT); + if (ret < 0) + return ret; + ret &= 0x7ff; + break; + case PMBUS_VOUT_OV_FAULT_LIMIT: + case PMBUS_VOUT_UV_FAULT_LIMIT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + ret &= 0x7ff; + break; + default: + ret = -ENODATA; + break; + } + + return ret; +} + +/* + * The vout under- and over-voltage limits are set as an offset relative to + * the commanded vout voltage. The vin, iout, pout and temp limits must use + * the same fixed exponent the chip uses to encode the data when read. + */ +static int stpddc60_write_word_data(struct i2c_client *client, int page, + int reg, u16 word) +{ + int ret; + u8 offset; + + if (page > 0) + return -ENXIO; + + switch (reg) { + case PMBUS_VOUT_OV_FAULT_LIMIT: + ret = pmbus_read_word_data(client, page, 0xff, + PMBUS_VOUT_COMMAND); + if (ret < 0) + return ret; + offset = stpddc60_get_offset(ret, word, true); + ret = pmbus_write_byte_data(client, page, + STPDDC60_MFR_OV_LIMIT_OFFSET, + offset); + break; + case PMBUS_VOUT_UV_FAULT_LIMIT: + ret = pmbus_read_word_data(client, page, 0xff, + PMBUS_VOUT_COMMAND); + if (ret < 0) + return ret; + offset = stpddc60_get_offset(ret, word, false); + ret = pmbus_write_byte_data(client, page, + STPDDC60_MFR_UV_LIMIT_OFFSET, + offset); + break; + case PMBUS_VIN_OV_FAULT_LIMIT: + case PMBUS_VIN_UV_FAULT_LIMIT: + case PMBUS_OT_FAULT_LIMIT: + case PMBUS_OT_WARN_LIMIT: + case PMBUS_IOUT_OC_FAULT_LIMIT: + case PMBUS_IOUT_OC_WARN_LIMIT: + case PMBUS_POUT_OP_FAULT_LIMIT: + ret = pmbus_read_word_data(client, page, 0xff, reg); + if (ret < 0) + return ret; + word = stpddc60_adjust_linear(word, ret >> 11); + ret = pmbus_write_word_data(client, page, reg, word); + break; + default: + ret = -ENODATA; + break; + } + + return ret; +} + +static int stpddc60_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 = &stpddc60_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_MFR_MODEL, device_id); + if (status < 0) { + dev_err(&client->dev, "Failed to read Manufacturer Model\n"); + return status; + } + for (mid = stpddc60_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; + } + + info->read_byte_data = stpddc60_read_byte_data; + info->read_word_data = stpddc60_read_word_data; + info->write_word_data = stpddc60_write_word_data; + + status = pmbus_do_probe(client, info); + if (status < 0) + return status; + + pmbus_set_update(client, PMBUS_VOUT_OV_FAULT_LIMIT, true); + pmbus_set_update(client, PMBUS_VOUT_UV_FAULT_LIMIT, true); + + return 0; +} + +static struct i2c_driver stpddc60_driver = { + .driver = { + .name = "stpddc60", + }, + .probe_new = stpddc60_probe, + .id_table = stpddc60_id, +}; + +module_i2c_driver(stpddc60_driver); + +MODULE_AUTHOR("Erik Rosen <erik.rosen@metormote.com>"); +MODULE_DESCRIPTION("PMBus driver for ST STPDDC60"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(PMBUS); |