2023-11-22 18:54:37 -07:00
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// SPDX-License-Identifier: GPL-2.0-or-later
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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/pmbus.h>
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#include "pmbus.h"
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/* LTC4286 register */
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#define LTC4286_MFR_CONFIG1 0xF2
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/* LTC4286 configuration */
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#define VRANGE_SELECT_BIT BIT(1)
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#define LTC4286_MFR_ID_SIZE 3
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/*
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* Initialize the MBR as default settings which is referred to LTC4286 datasheet
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* (March 22, 2022 version) table 3 page 16
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*/
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static struct pmbus_driver_info ltc4286_info = {
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.pages = 1,
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.format[PSC_VOLTAGE_IN] = direct,
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.format[PSC_VOLTAGE_OUT] = direct,
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.format[PSC_CURRENT_OUT] = direct,
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.format[PSC_POWER] = direct,
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.format[PSC_TEMPERATURE] = direct,
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.m[PSC_VOLTAGE_IN] = 32,
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.b[PSC_VOLTAGE_IN] = 0,
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.R[PSC_VOLTAGE_IN] = 1,
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.m[PSC_VOLTAGE_OUT] = 32,
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.b[PSC_VOLTAGE_OUT] = 0,
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.R[PSC_VOLTAGE_OUT] = 1,
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.m[PSC_CURRENT_OUT] = 1024,
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.b[PSC_CURRENT_OUT] = 0,
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/*
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* The rsense value used in MBR formula in LTC4286 datasheet should be ohm unit.
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* However, the rsense value that user input is micro ohm.
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* Thus, the MBR setting which involves rsense should be shifted by 6 digits.
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*/
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.R[PSC_CURRENT_OUT] = 3 - 6,
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.m[PSC_POWER] = 1,
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.b[PSC_POWER] = 0,
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/*
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* The rsense value used in MBR formula in LTC4286 datasheet should be ohm unit.
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* However, the rsense value that user input is micro ohm.
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* Thus, the MBR setting which involves rsense should be shifted by 6 digits.
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*/
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.R[PSC_POWER] = 4 - 6,
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.m[PSC_TEMPERATURE] = 1,
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.b[PSC_TEMPERATURE] = 273,
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.R[PSC_TEMPERATURE] = 0,
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.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
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PMBUS_HAVE_PIN | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_VOUT |
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PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_TEMP,
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};
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static const struct i2c_device_id ltc4286_id[] = {
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2024-07-10 01:35:45 -07:00
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{ "ltc4286", },
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{ "ltc4287", },
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2023-11-22 18:54:37 -07:00
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ltc4286_id);
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static int ltc4286_probe(struct i2c_client *client)
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{
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int ret;
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const struct i2c_device_id *mid;
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u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
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struct pmbus_driver_info *info;
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u32 rsense;
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int vrange_nval, vrange_oval;
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ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, block_buffer);
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if (ret < 0) {
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return dev_err_probe(&client->dev, ret,
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"Failed to read manufacturer id\n");
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}
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/*
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* Refer to ltc4286 datasheet page 20
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* the manufacturer id is LTC
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*/
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if (ret != LTC4286_MFR_ID_SIZE ||
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strncmp(block_buffer, "LTC", LTC4286_MFR_ID_SIZE)) {
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return dev_err_probe(&client->dev, -ENODEV,
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"Manufacturer id mismatch\n");
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}
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ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, block_buffer);
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if (ret < 0) {
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return dev_err_probe(&client->dev, ret,
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"Failed to read manufacturer model\n");
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}
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for (mid = ltc4286_id; mid->name[0]; mid++) {
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if (!strncasecmp(mid->name, block_buffer, strlen(mid->name)))
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break;
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}
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if (!mid->name[0])
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return dev_err_probe(&client->dev, -ENODEV,
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"Unsupported device\n");
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if (of_property_read_u32(client->dev.of_node,
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"shunt-resistor-micro-ohms", &rsense))
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rsense = 300; /* 0.3 mOhm if not set via DT */
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if (rsense == 0)
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return -EINVAL;
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/* Check for the latter MBR value won't overflow */
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if (rsense > (INT_MAX / 1024))
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return -EINVAL;
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info = devm_kmemdup(&client->dev, <c4286_info, sizeof(*info),
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GFP_KERNEL);
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if (!info)
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return -ENOMEM;
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/* Check MFR1 CONFIG register bit 1 VRANGE_SELECT before driver loading */
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vrange_oval = i2c_smbus_read_word_data(client, LTC4286_MFR_CONFIG1);
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if (vrange_oval < 0)
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return dev_err_probe(&client->dev, vrange_oval,
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"Failed to read manufacturer configuration one\n");
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vrange_nval = vrange_oval;
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if (device_property_read_bool(&client->dev, "adi,vrange-low-enable")) {
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vrange_nval &=
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~VRANGE_SELECT_BIT; /* VRANGE_SELECT = 0, 25.6 volts */
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info->m[PSC_VOLTAGE_IN] = 128;
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info->m[PSC_VOLTAGE_OUT] = 128;
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info->m[PSC_POWER] = 4 * rsense;
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} else {
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vrange_nval |=
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VRANGE_SELECT_BIT; /* VRANGE_SELECT = 1, 102.4 volts */
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info->m[PSC_POWER] = rsense;
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}
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if (vrange_nval != vrange_oval) {
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/* Set MFR1 CONFIG register bit 1 VRANGE_SELECT */
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ret = i2c_smbus_write_word_data(client, LTC4286_MFR_CONFIG1,
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vrange_nval);
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if (ret < 0)
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return dev_err_probe(&client->dev, ret,
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"Failed to set vrange\n");
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}
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info->m[PSC_CURRENT_OUT] = 1024 * rsense;
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return pmbus_do_probe(client, info);
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}
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static const struct of_device_id ltc4286_of_match[] = {
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{ .compatible = "lltc,ltc4286" },
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{ .compatible = "lltc,ltc4287" },
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{}
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};
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static struct i2c_driver ltc4286_driver = {
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.driver = {
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.name = "ltc4286",
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.of_match_table = ltc4286_of_match,
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},
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.probe = ltc4286_probe,
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.id_table = ltc4286_id,
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};
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module_i2c_driver(ltc4286_driver);
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MODULE_AUTHOR("Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com>");
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MODULE_DESCRIPTION("PMBUS driver for LTC4286 and compatibles");
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MODULE_LICENSE("GPL");
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