diff options
Diffstat (limited to 'drivers/hwmon/pmbus/max20730.c')
| -rw-r--r-- | drivers/hwmon/pmbus/max20730.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c new file mode 100644 index 000000000000..294e2212f61e --- /dev/null +++ b/drivers/hwmon/pmbus/max20730.c @@ -0,0 +1,372 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for MAX20730, MAX20734, and MAX20743 Integrated, Step-Down + * Switching Regulators + * + * Copyright 2019 Google LLC. + */ + +#include <linux/bits.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of_device.h> +#include <linux/pmbus.h> +#include <linux/util_macros.h> +#include "pmbus.h" + +enum chips { + max20730, + max20734, + max20743 +}; + +struct max20730_data { + enum chips id; + struct pmbus_driver_info info; + struct mutex lock; /* Used to protect against parallel writes */ + u16 mfr_devset1; +}; + +#define to_max20730_data(x) container_of(x, struct max20730_data, info) + +#define MAX20730_MFR_DEVSET1 0xd2 + +/* + * Convert discreet value to direct data format. Strictly speaking, all passed + * values are constants, so we could do that calculation manually. On the + * downside, that would make the driver more difficult to maintain, so lets + * use this approach. + */ +static u16 val_to_direct(int v, enum pmbus_sensor_classes class, + const struct pmbus_driver_info *info) +{ + int R = info->R[class] - 3; /* take milli-units into account */ + int b = info->b[class] * 1000; + long d; + + d = v * info->m[class] + b; + /* + * R < 0 is true for all callers, so we don't need to bother + * about the R > 0 case. + */ + while (R < 0) { + d = DIV_ROUND_CLOSEST(d, 10); + R++; + } + return (u16)d; +} + +static long direct_to_val(u16 w, enum pmbus_sensor_classes class, + const struct pmbus_driver_info *info) +{ + int R = info->R[class] - 3; + int b = info->b[class] * 1000; + int m = info->m[class]; + long d = (s16)w; + + if (m == 0) + return 0; + + while (R < 0) { + d *= 10; + R++; + } + d = (d - b) / m; + return d; +} + +static u32 max_current[][5] = { + [max20730] = { 13000, 16600, 20100, 23600 }, + [max20734] = { 21000, 27000, 32000, 38000 }, + [max20743] = { 18900, 24100, 29200, 34100 }, +}; + +static int max20730_read_word_data(struct i2c_client *client, int page, int reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + const struct max20730_data *data = to_max20730_data(info); + int ret = 0; + u32 max_c; + + switch (reg) { + case PMBUS_OT_FAULT_LIMIT: + switch ((data->mfr_devset1 >> 11) & 0x3) { + case 0x0: + ret = val_to_direct(150000, PSC_TEMPERATURE, info); + break; + case 0x1: + ret = val_to_direct(130000, PSC_TEMPERATURE, info); + break; + default: + ret = -ENODATA; + break; + } + break; + case PMBUS_IOUT_OC_FAULT_LIMIT: + max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3]; + ret = val_to_direct(max_c, PSC_CURRENT_OUT, info); + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + +static int max20730_write_word_data(struct i2c_client *client, int page, + int reg, u16 word) +{ + struct pmbus_driver_info *info; + struct max20730_data *data; + u16 devset1; + int ret = 0; + int idx; + + info = (struct pmbus_driver_info *)pmbus_get_driver_info(client); + data = to_max20730_data(info); + + mutex_lock(&data->lock); + devset1 = data->mfr_devset1; + + switch (reg) { + case PMBUS_OT_FAULT_LIMIT: + devset1 &= ~(BIT(11) | BIT(12)); + if (direct_to_val(word, PSC_TEMPERATURE, info) < 140000) + devset1 |= BIT(11); + break; + case PMBUS_IOUT_OC_FAULT_LIMIT: + devset1 &= ~(BIT(5) | BIT(6)); + + idx = find_closest(direct_to_val(word, PSC_CURRENT_OUT, info), + max_current[data->id], 4); + devset1 |= (idx << 5); + break; + default: + ret = -ENODATA; + break; + } + + if (!ret && devset1 != data->mfr_devset1) { + ret = i2c_smbus_write_word_data(client, MAX20730_MFR_DEVSET1, + devset1); + if (!ret) { + data->mfr_devset1 = devset1; + pmbus_clear_cache(client); + } + } + mutex_unlock(&data->lock); + return ret; +} + +static const struct pmbus_driver_info max20730_info[] = { + [max20730] = { + .pages = 1, + .read_word_data = max20730_read_word_data, + .write_word_data = max20730_write_word_data, + + /* Source : Maxim AN6042 */ + .format[PSC_TEMPERATURE] = direct, + .m[PSC_TEMPERATURE] = 21, + .b[PSC_TEMPERATURE] = 5887, + .R[PSC_TEMPERATURE] = -1, + + .format[PSC_VOLTAGE_IN] = direct, + .m[PSC_VOLTAGE_IN] = 3609, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = -2, + + /* + * Values in the datasheet are adjusted for temperature and + * for the relationship between Vin and Vout. + * Unfortunately, the data sheet suggests that Vout measurement + * may be scaled with a resistor array. This is indeed the case + * at least on the evaulation boards. As a result, any in-driver + * adjustments would either be wrong or require elaborate means + * to configure the scaling. Instead of doing that, just report + * raw values and let userspace handle adjustments. + */ + .format[PSC_CURRENT_OUT] = direct, + .m[PSC_CURRENT_OUT] = 153, + .b[PSC_CURRENT_OUT] = 4976, + .R[PSC_CURRENT_OUT] = -1, + + .format[PSC_VOLTAGE_OUT] = linear, + + .func[0] = PMBUS_HAVE_VIN | + PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, + }, + [max20734] = { + .pages = 1, + .read_word_data = max20730_read_word_data, + .write_word_data = max20730_write_word_data, + + /* Source : Maxim AN6209 */ + .format[PSC_TEMPERATURE] = direct, + .m[PSC_TEMPERATURE] = 21, + .b[PSC_TEMPERATURE] = 5887, + .R[PSC_TEMPERATURE] = -1, + + .format[PSC_VOLTAGE_IN] = direct, + .m[PSC_VOLTAGE_IN] = 3592, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = -2, + + .format[PSC_CURRENT_OUT] = direct, + .m[PSC_CURRENT_OUT] = 111, + .b[PSC_CURRENT_OUT] = 3461, + .R[PSC_CURRENT_OUT] = -1, + + .format[PSC_VOLTAGE_OUT] = linear, + + .func[0] = PMBUS_HAVE_VIN | + PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, + }, + [max20743] = { + .pages = 1, + .read_word_data = max20730_read_word_data, + .write_word_data = max20730_write_word_data, + + /* Source : Maxim AN6042 */ + .format[PSC_TEMPERATURE] = direct, + .m[PSC_TEMPERATURE] = 21, + .b[PSC_TEMPERATURE] = 5887, + .R[PSC_TEMPERATURE] = -1, + + .format[PSC_VOLTAGE_IN] = direct, + .m[PSC_VOLTAGE_IN] = 3597, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = -2, + + .format[PSC_CURRENT_OUT] = direct, + .m[PSC_CURRENT_OUT] = 95, + .b[PSC_CURRENT_OUT] = 5014, + .R[PSC_CURRENT_OUT] = -1, + + .format[PSC_VOLTAGE_OUT] = linear, + + .func[0] = PMBUS_HAVE_VIN | + PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | + PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP, + }, +}; + +static int max20730_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; + struct max20730_data *data; + enum chips chip_id; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA | + I2C_FUNC_SMBUS_READ_WORD_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA)) + return -ENODEV; + + ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf); + if (ret < 0) { + dev_err(&client->dev, "Failed to read Manufacturer ID\n"); + return ret; + } + if (ret != 5 || strncmp(buf, "MAXIM", 5)) { + buf[ret] = '\0'; + dev_err(dev, "Unsupported Manufacturer ID '%s'\n", buf); + return -ENODEV; + } + + /* + * The chips support reading PMBUS_MFR_MODEL. On both MAX20730 + * and MAX20734, reading it returns M20743. Presumably that is + * the reason why the command is not documented. Unfortunately, + * that means that there is no reliable means to detect the chip. + * However, we can at least detect the chip series. Compare + * the returned value against 'M20743' and bail out if there is + * a mismatch. If that doesn't work for all chips, we may have + * to remove this check. + */ + ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf); + if (ret < 0) { + dev_err(dev, "Failed to read Manufacturer Model\n"); + return ret; + } + if (ret != 6 || strncmp(buf, "M20743", 6)) { + buf[ret] = '\0'; + dev_err(dev, "Unsupported Manufacturer Model '%s'\n", buf); + return -ENODEV; + } + + ret = i2c_smbus_read_block_data(client, PMBUS_MFR_REVISION, buf); + if (ret < 0) { + dev_err(dev, "Failed to read Manufacturer Revision\n"); + return ret; + } + if (ret != 1 || buf[0] != 'F') { + buf[ret] = '\0'; + dev_err(dev, "Unsupported Manufacturer Revision '%s'\n", buf); + return -ENODEV; + } + + if (client->dev.of_node) + chip_id = (enum chips)of_device_get_match_data(dev); + else + chip_id = id->driver_data; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + data->id = chip_id; + mutex_init(&data->lock); + memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info)); + + ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1); + if (ret < 0) + return ret; + data->mfr_devset1 = ret; + + return pmbus_do_probe(client, id, &data->info); +} + +static const struct i2c_device_id max20730_id[] = { + { "max20730", max20730 }, + { "max20734", max20734 }, + { "max20743", max20743 }, + { }, +}; + +MODULE_DEVICE_TABLE(i2c, max20730_id); + +static const struct of_device_id max20730_of_match[] = { + { .compatible = "maxim,max20730", .data = (void *)max20730 }, + { .compatible = "maxim,max20734", .data = (void *)max20734 }, + { .compatible = "maxim,max20743", .data = (void *)max20743 }, + { }, +}; + +MODULE_DEVICE_TABLE(of, max20730_of_match); + +static struct i2c_driver max20730_driver = { + .driver = { + .name = "max20730", + .of_match_table = max20730_of_match, + }, + .probe = max20730_probe, + .remove = pmbus_do_remove, + .id_table = max20730_id, +}; + +module_i2c_driver(max20730_driver); + +MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); +MODULE_DESCRIPTION("PMBus driver for Maxim MAX20730 / MAX20734 / MAX20743"); +MODULE_LICENSE("GPL"); |