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