| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Arun Saravanan Balachandran | 2050 | 100.00% | 1 | 100.00% |
| Total | 2050 | 1 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Hardware monitoring driver for Maxim MAX6620 * * Originally from L. Grunenberg. * (C) 2012 by L. Grunenberg <contact@lgrunenberg.de> * * Copyright (c) 2021 Dell Inc. or its subsidiaries. All Rights Reserved. * * based on code written by : * 2007 by Hans J. Koch <hjk@hansjkoch.de> * John Morris <john.morris@spirentcom.com> * Copyright (c) 2003 Spirent Communications * and Claus Gindhart <claus.gindhart@kontron.com> * * This module has only been tested with the MAX6620 chip. * * The datasheet was last seen at: * * http://pdfserv.maxim-ic.com/en/ds/MAX6620.pdf * */ #include <linux/bits.h> #include <linux/err.h> #include <linux/hwmon.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/jiffies.h> #include <linux/module.h> #include <linux/slab.h> /* * MAX 6620 registers */ #define MAX6620_REG_CONFIG 0x00 #define MAX6620_REG_FAULT 0x01 #define MAX6620_REG_CONF_FAN0 0x02 #define MAX6620_REG_CONF_FAN1 0x03 #define MAX6620_REG_CONF_FAN2 0x04 #define MAX6620_REG_CONF_FAN3 0x05 #define MAX6620_REG_DYN_FAN0 0x06 #define MAX6620_REG_DYN_FAN1 0x07 #define MAX6620_REG_DYN_FAN2 0x08 #define MAX6620_REG_DYN_FAN3 0x09 #define MAX6620_REG_TACH0 0x10 #define MAX6620_REG_TACH1 0x12 #define MAX6620_REG_TACH2 0x14 #define MAX6620_REG_TACH3 0x16 #define MAX6620_REG_VOLT0 0x18 #define MAX6620_REG_VOLT1 0x1A #define MAX6620_REG_VOLT2 0x1C #define MAX6620_REG_VOLT3 0x1E #define MAX6620_REG_TAR0 0x20 #define MAX6620_REG_TAR1 0x22 #define MAX6620_REG_TAR2 0x24 #define MAX6620_REG_TAR3 0x26 #define MAX6620_REG_DAC0 0x28 #define MAX6620_REG_DAC1 0x2A #define MAX6620_REG_DAC2 0x2C #define MAX6620_REG_DAC3 0x2E /* * Config register bits */ #define MAX6620_CFG_RUN BIT(7) #define MAX6620_CFG_POR BIT(6) #define MAX6620_CFG_TIMEOUT BIT(5) #define MAX6620_CFG_FULLFAN BIT(4) #define MAX6620_CFG_OSC BIT(3) #define MAX6620_CFG_WD_MASK (BIT(2) | BIT(1)) #define MAX6620_CFG_WD_2 BIT(1) #define MAX6620_CFG_WD_6 BIT(2) #define MAX6620_CFG_WD10 (BIT(2) | BIT(1)) #define MAX6620_CFG_WD BIT(0) /* * Failure status register bits */ #define MAX6620_FAIL_TACH0 BIT(4) #define MAX6620_FAIL_TACH1 BIT(5) #define MAX6620_FAIL_TACH2 BIT(6) #define MAX6620_FAIL_TACH3 BIT(7) #define MAX6620_FAIL_MASK0 BIT(0) #define MAX6620_FAIL_MASK1 BIT(1) #define MAX6620_FAIL_MASK2 BIT(2) #define MAX6620_FAIL_MASK3 BIT(3) #define MAX6620_CLOCK_FREQ 8192 /* Clock frequency in Hz */ #define MAX6620_PULSE_PER_REV 2 /* Tachometer pulses per revolution */ /* Minimum and maximum values of the FAN-RPM */ #define FAN_RPM_MIN 240 #define FAN_RPM_MAX 30000 static const u8 config_reg[] = { MAX6620_REG_CONF_FAN0, MAX6620_REG_CONF_FAN1, MAX6620_REG_CONF_FAN2, MAX6620_REG_CONF_FAN3, }; static const u8 dyn_reg[] = { MAX6620_REG_DYN_FAN0, MAX6620_REG_DYN_FAN1, MAX6620_REG_DYN_FAN2, MAX6620_REG_DYN_FAN3, }; static const u8 tach_reg[] = { MAX6620_REG_TACH0, MAX6620_REG_TACH1, MAX6620_REG_TACH2, MAX6620_REG_TACH3, }; static const u8 target_reg[] = { MAX6620_REG_TAR0, MAX6620_REG_TAR1, MAX6620_REG_TAR2, MAX6620_REG_TAR3, }; /* * Client data (each client gets its own) */ struct max6620_data { struct i2c_client *client; struct mutex update_lock; bool valid; /* false until following fields are valid */ unsigned long last_updated; /* in jiffies */ /* register values */ u8 fancfg[4]; u8 fandyn[4]; u8 fault; u16 tach[4]; u16 target[4]; }; static u8 max6620_fan_div_from_reg(u8 val) { return BIT((val & 0xE0) >> 5); } static u16 max6620_fan_rpm_to_tach(u8 div, int rpm) { return (60 * div * MAX6620_CLOCK_FREQ) / (rpm * MAX6620_PULSE_PER_REV); } static int max6620_fan_tach_to_rpm(u8 div, u16 tach) { return (60 * div * MAX6620_CLOCK_FREQ) / (tach * MAX6620_PULSE_PER_REV); } static int max6620_update_device(struct device *dev) { struct max6620_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; int i; int ret = 0; mutex_lock(&data->update_lock); if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { for (i = 0; i < 4; i++) { ret = i2c_smbus_read_byte_data(client, config_reg[i]); if (ret < 0) goto error; data->fancfg[i] = ret; ret = i2c_smbus_read_byte_data(client, dyn_reg[i]); if (ret < 0) goto error; data->fandyn[i] = ret; ret = i2c_smbus_read_byte_data(client, tach_reg[i]); if (ret < 0) goto error; data->tach[i] = (ret << 3) & 0x7f8; ret = i2c_smbus_read_byte_data(client, tach_reg[i] + 1); if (ret < 0) goto error; data->tach[i] |= (ret >> 5) & 0x7; ret = i2c_smbus_read_byte_data(client, target_reg[i]); if (ret < 0) goto error; data->target[i] = (ret << 3) & 0x7f8; ret = i2c_smbus_read_byte_data(client, target_reg[i] + 1); if (ret < 0) goto error; data->target[i] |= (ret >> 5) & 0x7; } /* * Alarms are cleared on read in case the condition that * caused the alarm is removed. Keep the value latched here * for providing the register through different alarm files. */ ret = i2c_smbus_read_byte_data(client, MAX6620_REG_FAULT); if (ret < 0) goto error; data->fault |= (ret >> 4) & (ret & 0x0F); data->last_updated = jiffies; data->valid = true; } error: mutex_unlock(&data->update_lock); return ret; } static umode_t max6620_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { switch (type) { case hwmon_fan: switch (attr) { case hwmon_fan_alarm: case hwmon_fan_input: return 0444; case hwmon_fan_div: case hwmon_fan_target: return 0644; default: break; } break; default: break; } return 0; } static int max6620_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct max6620_data *data; struct i2c_client *client; int ret; u8 div; u8 val1; u8 val2; ret = max6620_update_device(dev); if (ret < 0) return ret; data = dev_get_drvdata(dev); client = data->client; switch (type) { case hwmon_fan: switch (attr) { case hwmon_fan_alarm: mutex_lock(&data->update_lock); *val = !!(data->fault & BIT(channel)); /* Setting TACH count to re-enable fan fault detection */ if (*val == 1) { val1 = (data->target[channel] >> 3) & 0xff; val2 = (data->target[channel] << 5) & 0xe0; ret = i2c_smbus_write_byte_data(client, target_reg[channel], val1); if (ret < 0) { mutex_unlock(&data->update_lock); return ret; } ret = i2c_smbus_write_byte_data(client, target_reg[channel] + 1, val2); if (ret < 0) { mutex_unlock(&data->update_lock); return ret; } data->fault &= ~BIT(channel); } mutex_unlock(&data->update_lock); break; case hwmon_fan_div: *val = max6620_fan_div_from_reg(data->fandyn[channel]); break; case hwmon_fan_input: if (data->tach[channel] == 0) { *val = 0; } else { div = max6620_fan_div_from_reg(data->fandyn[channel]); *val = max6620_fan_tach_to_rpm(div, data->tach[channel]); } break; case hwmon_fan_target: if (data->target[channel] == 0) { *val = 0; } else { div = max6620_fan_div_from_reg(data->fandyn[channel]); *val = max6620_fan_tach_to_rpm(div, data->target[channel]); } break; default: return -EOPNOTSUPP; } break; default: return -EOPNOTSUPP; } return 0; } static int max6620_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) { struct max6620_data *data; struct i2c_client *client; int ret; u8 div; u16 tach; u8 val1; u8 val2; ret = max6620_update_device(dev); if (ret < 0) return ret; data = dev_get_drvdata(dev); client = data->client; mutex_lock(&data->update_lock); switch (type) { case hwmon_fan: switch (attr) { case hwmon_fan_div: switch (val) { case 1: div = 0; break; case 2: div = 1; break; case 4: div = 2; break; case 8: div = 3; break; case 16: div = 4; break; case 32: div = 5; break; default: ret = -EINVAL; goto error; } data->fandyn[channel] &= 0x1F; data->fandyn[channel] |= div << 5; ret = i2c_smbus_write_byte_data(client, dyn_reg[channel], data->fandyn[channel]); break; case hwmon_fan_target: val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX); div = max6620_fan_div_from_reg(data->fandyn[channel]); tach = max6620_fan_rpm_to_tach(div, val); val1 = (tach >> 3) & 0xff; val2 = (tach << 5) & 0xe0; ret = i2c_smbus_write_byte_data(client, target_reg[channel], val1); if (ret < 0) break; ret = i2c_smbus_write_byte_data(client, target_reg[channel] + 1, val2); if (ret < 0) break; /* Setting TACH count re-enables fan fault detection */ data->fault &= ~BIT(channel); break; default: ret = -EOPNOTSUPP; break; } break; default: ret = -EOPNOTSUPP; break; } error: mutex_unlock(&data->update_lock); return ret; } static const struct hwmon_channel_info *max6620_info[] = { HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM, HWMON_F_INPUT | HWMON_F_DIV | HWMON_F_TARGET | HWMON_F_ALARM), NULL }; static const struct hwmon_ops max6620_hwmon_ops = { .read = max6620_read, .write = max6620_write, .is_visible = max6620_is_visible, }; static const struct hwmon_chip_info max6620_chip_info = { .ops = &max6620_hwmon_ops, .info = max6620_info, }; static int max6620_init_client(struct max6620_data *data) { struct i2c_client *client = data->client; int config; int err; int i; int reg; config = i2c_smbus_read_byte_data(client, MAX6620_REG_CONFIG); if (config < 0) { dev_err(&client->dev, "Error reading config, aborting.\n"); return config; } /* * Set bit 4, disable other fans from going full speed on a fail * failure. */ err = i2c_smbus_write_byte_data(client, MAX6620_REG_CONFIG, config | 0x10); if (err < 0) { dev_err(&client->dev, "Config write error, aborting.\n"); return err; } for (i = 0; i < 4; i++) { reg = i2c_smbus_read_byte_data(client, config_reg[i]); if (reg < 0) return reg; data->fancfg[i] = reg; /* Enable RPM mode */ data->fancfg[i] |= 0xa8; err = i2c_smbus_write_byte_data(client, config_reg[i], data->fancfg[i]); if (err < 0) return err; /* 2 counts (001) and Rate change 100 (0.125 secs) */ data->fandyn[i] = 0x30; err = i2c_smbus_write_byte_data(client, dyn_reg[i], data->fandyn[i]); if (err < 0) return err; } return 0; } static int max6620_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct max6620_data *data; struct device *hwmon_dev; int err; data = devm_kzalloc(dev, sizeof(struct max6620_data), GFP_KERNEL); if (!data) return -ENOMEM; data->client = client; mutex_init(&data->update_lock); err = max6620_init_client(data); if (err) return err; hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, &max6620_chip_info, NULL); return PTR_ERR_OR_ZERO(hwmon_dev); } static const struct i2c_device_id max6620_id[] = { { "max6620", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, max6620_id); static struct i2c_driver max6620_driver = { .class = I2C_CLASS_HWMON, .driver = { .name = "max6620", }, .probe_new = max6620_probe, .id_table = max6620_id, }; module_i2c_driver(max6620_driver); MODULE_AUTHOR("Lucas Grunenberg"); MODULE_DESCRIPTION("MAX6620 sensor driver"); MODULE_LICENSE("GPL");
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