On Mon, Jul 04, 2022 at 04:06:05PM +0000, Ibrahim Tilki wrote:
> MAX31760 is a presicion fan speed controller with nonvolatile lookup table.
> Device has one internal and one external temperature sensor support.
> Controls two fans and measures their speeds.
> Generates hardware alerts when programmable max and critical temperatures are exceeded.
>
> Driver creates following sysfs attributes for configuring lookup table:
> pwm1_auto_point[1-48]_{pwm,temp,temp_hyst}
>
> Signed-off-by: Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>
> Reviewed-by: Nurettin Bolucu <Nurettin.Bolucu@xxxxxxxxxx>
> ---
> drivers/hwmon/Kconfig | 10 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/max31760.c | 614 +++++++++++++++++++++++++++++++++++++++
Please add doucmentation describing the supported sysfs attributes.
> 3 files changed, 625 insertions(+)
> create mode 100644 drivers/hwmon/max31760.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 590d3d550..59cc44a5c 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1065,6 +1065,16 @@ config SENSORS_MAX31730
> This driver can also be built as a module. If so, the module
> will be called max31730.
>
> +config SENSORS_MAX31760
> + tristate "MAX31760 fan speed controller"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Support for the Analog Devices MAX31760 Fan Speed Controller.
> +
> + This driver can also be built as a module. If so, the module
> + will be called max31760.
> +
> config SENSORS_MAX6620
> tristate "Maxim MAX6620 fan controller"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 007e829d1..1c0fa4dd8 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -140,6 +140,7 @@ obj-$(CONFIG_SENSORS_MAX1668) += max1668.o
> obj-$(CONFIG_SENSORS_MAX197) += max197.o
> obj-$(CONFIG_SENSORS_MAX31722) += max31722.o
> obj-$(CONFIG_SENSORS_MAX31730) += max31730.o
> +obj-$(CONFIG_SENSORS_MAX31760) += max31760.o
> obj-$(CONFIG_SENSORS_MAX6620) += max6620.o
> obj-$(CONFIG_SENSORS_MAX6621) += max6621.o
> obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
> diff --git a/drivers/hwmon/max31760.c b/drivers/hwmon/max31760.c
> new file mode 100644
> index 000000000..ade3570a8
> --- /dev/null
> +++ b/drivers/hwmon/max31760.c
> @@ -0,0 +1,614 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/err.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/util_macros.h>
> +
> +#define REG_CR1 0x00
> +#define CR1_HYST BIT(5)
> +#define CR1_DRV GENMASK(4, 3)
> +#define CR1_TEMP_SRC GENMASK(1, 0)
> +#define REG_CR2 0x01
> +#define CR2_STBY BIT(7)
> +#define CR2_ALERTS BIT(6)
> +#define CR2_DFC BIT(0)
> +#define REG_CR3 0x02
> +#define REG_PWMR 0x50
> +#define REG_PWMV 0x51
> +#define REG_STATUS 0x5A
> +#define STATUS_ALARM_CRIT(ch) BIT(2 + 2 * (ch))
> +#define STATUS_ALARM_MAX(ch) BIT(3 + 2 * (ch))
> +#define STATUS_RDFA BIT(6)
> +
> +#define REG_TACH(ch) (0x52 + (ch) * 2)
> +#define REG_TEMP_INPUT(ch) (0x56 + (ch) * 2)
> +#define REG_TEMP_MAX(ch) (0x06 + (ch) * 2)
> +#define REG_TEMP_CRIT(ch) (0x0A + (ch) * 2)
> +
> +#define TEMP11_FROM_REG(reg) ((reg) / 32 * 125)
> +#define TEMP11_TO_REG(val) (DIV_ROUND_CLOSEST(clamp_val((val), -128000, \
> + 127875), 125) * 32)
> +
> +#define LUT_SIZE 48
> +#define LUT_PWM 0
> +#define LUT_TEMP 1
> +#define LUT_HYST 2
> +
> +#define REG_LUT(index) (0x20 + (index))
> +
> +struct max31760_state {
> + struct regmap *regmap;
> +
> + struct lut_attribute {
> + char name[32];
> + struct sensor_device_attribute_2 sda;
> + } lut[LUT_SIZE][3];
> +
> + struct attribute *attrs[LUT_SIZE * 3 + 1];
> + struct attribute_group group;
> + const struct attribute_group *groups[2];
> +};
> +
> +static const struct regmap_config regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = 0x5B
> +};
> +
> +static const int max31760_pwm_freq[] = {33, 150, 1500, 25000};
> +
> +static int tach_to_rpm(int tach)
> +{
> + int pulse_per_rev = 2;
> +
> + return 60 * 100000 / tach / pulse_per_rev;
pulse_per_rev is unnecessary. If anything, make it a define.
> +}
> +
> +static int max31760_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct max31760_state *state = dev_get_drvdata(dev);
> + unsigned int regval;
> + unsigned int reg_temp;
> + s16 temp;
> + s16 temp_hyst = 0;
> + u8 reg[2];
> + int ret;
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_fault:
> + ret = regmap_read(state->regmap, REG_STATUS, ®val);
> + if (ret)
> + return ret;
> +
> + *val = FIELD_GET(STATUS_RDFA, regval);
> +
> + return 0;
> + case hwmon_temp_max_alarm:
> + ret = regmap_read(state->regmap, REG_STATUS, ®val);
> + if (ret)
> + return ret;
> +
> + if (channel)
> + *val = FIELD_GET(STATUS_ALARM_MAX(1), regval);
> + else
> + *val = FIELD_GET(STATUS_ALARM_MAX(0), regval);
> +
> + return 0;
> + case hwmon_temp_crit_alarm:
> + ret = regmap_read(state->regmap, REG_STATUS, ®val);
> + if (ret)
> + return ret;
> +
> + if (channel)
> + *val = FIELD_GET(STATUS_ALARM_CRIT(1), regval);
> + else
> + *val = FIELD_GET(STATUS_ALARM_CRIT(0), regval);
> +
> + return 0;
> + case hwmon_temp_input:
> + reg_temp = REG_TEMP_INPUT(channel);
> + break;
> + case hwmon_temp_max_hyst:
> + temp_hyst = 1000;
> + fallthrough;
Please drop constant attributes; they add no value. Document the hysteresis values
in the driver documentation if you like.
> + case hwmon_temp_max:
> + reg_temp = REG_TEMP_MAX(channel);
> + break;
> + case hwmon_temp_crit_hyst:
> + temp_hyst = 10000;
> + fallthrough;
> + case hwmon_temp_crit:
> + reg_temp = REG_TEMP_CRIT(channel);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + ret = regmap_bulk_read(state->regmap, reg_temp, reg, 2);
> + if (ret)
> + return ret;
> +
> + temp = (reg[0] << 8) | reg[1];
> +
> + *val = TEMP11_FROM_REG(temp) - temp_hyst;
> +
> + return 0;
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_input:
> + ret = regmap_bulk_read(state->regmap, REG_TACH(channel), reg, 2);
> + if (ret)
> + return ret;
> +
> + *val = tach_to_rpm(reg[0] * 256 + reg[1]);
> +
> + return 0;
> + case hwmon_fan_fault:
> + ret = regmap_read(state->regmap, REG_STATUS, ®val);
> + if (ret)
> + return ret;
> +
> + if (channel)
> + *val = FIELD_GET(BIT(1), regval);
> + else
> + *val = FIELD_GET(BIT(0), regval);
> +
> + return 0;
> + case hwmon_fan_enable:
> + ret = regmap_read(state->regmap, REG_CR3, ®val);
> + if (ret)
> + return ret;
> +
> + if (channel)
> + *val = FIELD_GET(BIT(1), regval);
> + else
> + *val = FIELD_GET(BIT(0), regval);
> +
> + return 0;
> + default:
> + return -EOPNOTSUPP;
> + }
> + case hwmon_pwm:
> + switch (attr) {
> + case hwmon_pwm_input:
> + ret = regmap_read(state->regmap, REG_PWMV, ®val);
> + if (ret)
> + return ret;
> +
> + *val = regval;
> +
> + return 0;
> + case hwmon_pwm_freq:
> + ret = regmap_read(state->regmap, REG_CR1, ®val);
> + if (ret)
> + return ret;
> +
> + regval = FIELD_GET(CR1_DRV, regval);
> + if (regval >= ARRAY_SIZE(max31760_pwm_freq))
> + return -EINVAL;
> +
> + *val = max31760_pwm_freq[regval];
> +
> + return 0;
> + case hwmon_pwm_enable:
> + ret = regmap_read(state->regmap, REG_CR2, ®val);
> + if (ret)
> + return ret;
> +
> + *val = 2 - FIELD_GET(CR2_DFC, regval);
> +
> + return 0;
> + case hwmon_pwm_auto_channels_temp:
> + ret = regmap_read(state->regmap, REG_CR1, ®val);
> + if (ret)
> + return ret;
> +
> + switch (FIELD_GET(CR1_TEMP_SRC, regval)) {
> + case 0:
> + *val = 2;
> + break;
> + case 1:
> + *val = 1;
> + break;
> + case 2:
> + case 3:
> + *val = 3;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> + default:
> + return -EOPNOTSUPP;
> + }
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static int max31760_write(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long val)
> +{
> + struct max31760_state *state = dev_get_drvdata(dev);
> + int ret;
> + unsigned int pwm_index;
> + unsigned int reg_temp;
> + int temp;
> + u8 reg_val[2];
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_max:
> + reg_temp = REG_TEMP_MAX(channel);
> + break;
> + case hwmon_temp_crit:
> + reg_temp = REG_TEMP_CRIT(channel);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> +
> + temp = TEMP11_TO_REG(val);
> + reg_val[0] = temp >> 8;
> + reg_val[1] = temp & 0xFF;
> +
> + /* Ensure alert output is in comparator mode */
> + ret = regmap_set_bits(state->regmap, REG_CR2, CR2_ALERTS);
> + if (ret)
> + return ret;
> +
> + return regmap_bulk_write(state->regmap, reg_temp, reg_val, 2);
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_enable:
> + if (val)
> + return regmap_set_bits(state->regmap, REG_CR3, BIT(channel));
There should really be some value checking. "enable" should be well defined,
not "anything but 0".
> + return regmap_clear_bits(state->regmap, REG_CR3, BIT(channel));
> + default:
> + return -EOPNOTSUPP;
> + }
> + case hwmon_pwm:
> + switch (attr) {
> + case hwmon_pwm_input:
> + if (val < 0 || val > 255)
> + return -EINVAL;
> +
> + return regmap_write(state->regmap, REG_PWMR, val);
> + case hwmon_pwm_enable:
> + if (val == 0)
> + return -EOPNOTSUPP;
> +
> + if (val == 1)
> + return regmap_set_bits(state->regmap, REG_CR2, CR2_DFC);
> +
Accepting all other values ?
> + return regmap_clear_bits(state->regmap, REG_CR2, CR2_DFC);
> + case hwmon_pwm_freq:
> + pwm_index = find_closest(val, max31760_pwm_freq,
> + ARRAY_SIZE(max31760_pwm_freq));
> +
> + return regmap_update_bits(state->regmap,
> + REG_CR1, CR1_DRV,
> + FIELD_PREP(CR1_DRV, pwm_index));
> + case hwmon_pwm_auto_channels_temp:
> + switch (val) {
> + case 1:
> + break;
> + case 2:
> + val = 0;
> + break;
> + case 3:
> + val = 2;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(state->regmap, REG_CR1, CR1_TEMP_SRC, val);
> + default:
> + return -EOPNOTSUPP;
> + }
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static const struct hwmon_channel_info *max31760_info[] = {
> + HWMON_CHANNEL_INFO(chip,
> + HWMON_C_REGISTER_TZ),
> + HWMON_CHANNEL_INFO(fan,
> + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE,
> + HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE),
> + HWMON_CHANNEL_INFO(temp,
> + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
> + HWMON_T_MAX_HYST | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
> + HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL,
> + HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
> + HWMON_T_MAX_HYST | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
> + HWMON_T_CRIT_ALARM | HWMON_T_LABEL),
> + HWMON_CHANNEL_INFO(pwm,
> + HWMON_PWM_ENABLE | HWMON_PWM_FREQ | HWMON_PWM_INPUT |
> + HWMON_PWM_AUTO_CHANNELS_TEMP),
> + NULL
> +};
> +
> +static umode_t max31760_is_visible(const void *data,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_input:
> + case hwmon_temp_max_alarm:
> + case hwmon_temp_crit_alarm:
> + case hwmon_temp_fault:
> + case hwmon_temp_label:
> + case hwmon_temp_max_hyst:
> + case hwmon_temp_crit_hyst:
> + return 0444;
> + case hwmon_temp_max:
> + case hwmon_temp_crit:
> + return 0644;
> + default:
> + return 0;
> + }
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_input:
> + case hwmon_fan_fault:
> + return 0444;
> + case hwmon_fan_enable:
> + return 0644;
> + default:
> + return 0;
> + }
> + case hwmon_pwm:
> + switch (attr) {
> + case hwmon_pwm_enable:
> + case hwmon_pwm_input:
> + case hwmon_pwm_freq:
> + case hwmon_pwm_auto_channels_temp:
> + return 0644;
> + default:
> + return 0;
> + }
> + default:
> + return 0;
> + }
> +}
> +
> +int max31760_read_string(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, const char **str)
> +{
> + switch (type) {
> + case hwmon_temp:
> + if (attr != hwmon_temp_label)
> + return -EOPNOTSUPP;
> +
> + *str = channel ? "local" : "remote";
> +
> + return 0;
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +
> +static const struct hwmon_ops max31760_hwmon_ops = {
> + .is_visible = max31760_is_visible,
> + .read = max31760_read,
> + .write = max31760_write,
> + .read_string = max31760_read_string
> +};
> +
> +static const struct hwmon_chip_info max31760_chip_info = {
> + .ops = &max31760_hwmon_ops,
> + .info = max31760_info,
> +};
> +
> +static ssize_t lut_show(struct device *dev,
> + struct device_attribute *devattr, char *buf)
> +{
> + struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(devattr);
> + struct max31760_state *state = dev_get_drvdata(dev);
> + int ret;
> + int temp;
> + unsigned int regval;
> +
> + switch (sda->nr) {
> + case LUT_PWM:
> + ret = regmap_read(state->regmap, REG_LUT(sda->index), ®val);
> + if (ret)
> + return ret;
> +
> + return sprintf(buf, "%d\n", regval);
> + case LUT_TEMP:
> + temp = 18;
> + break;
> + case LUT_HYST:
> + ret = regmap_read(state->regmap, REG_CR1, ®val);
> + if (ret)
> + return ret;
> +
> + temp = 16 - 2 * FIELD_GET(CR1_HYST, regval);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return sprintf(buf, "%d\n", (temp + 2 * sda->index) * 1000);
> +}
> +
> +static ssize_t lut_store(struct device *dev,
> + struct device_attribute *devattr,
> + const char *buf, size_t count)
> +{
> + struct sensor_device_attribute_2 *sda = to_sensor_dev_attr_2(devattr);
> + struct max31760_state *state = dev_get_drvdata(dev);
> + unsigned int pwm, hyst, temp;
> + int ret;
> +
> + switch (sda->nr) {
> + case LUT_PWM:
> + ret = kstrtou32(buf, 10, &pwm);
> + if (ret)
> + return ret;
> +
> + pwm = clamp_val(pwm, 0, 255);
pwm values should not be clamped on write. Bad values (outside 0..255) should be rejected.
> +
> + ret = regmap_write(state->regmap, REG_LUT(sda->index), pwm);
> + if (ret)
> + return ret;
> +
> + break;
> + case LUT_HYST:
> + ret = kstrtou32(buf, 10, &hyst);
> + if (ret)
> + return ret;
> +
> + temp = (18 + 2 * sda->index) * 1000;
> + /* LUT Hysteresis is either 2 or 4 degrees */
> + if (temp > hyst + 3000)
> + ret = regmap_set_bits(state->regmap, REG_CR1, CR1_HYST);
> + else
> + ret = regmap_clear_bits(state->regmap, REG_CR1, CR1_HYST);
> +
> + if (ret)
> + return ret;
> +
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return count;
> +}
> +
> +static void max31760_create_lut_nodes(struct max31760_state *state)
> +{
> + int i, nr;
> + struct sensor_device_attribute_2 *sda;
> + struct lut_attribute *lut;
> +
> + for (i = 0; i < LUT_SIZE; ++i) {
> + for (nr = 0; nr < 3; ++nr) {
> + lut = &state->lut[i][nr];
> + sda = &lut->sda;
> +
> + switch (nr) {
> + case LUT_PWM:
> + snprintf(lut->name, sizeof(lut->name),
> + "pwm1_auto_point%d_pwm", i + 1);
> + sda->dev_attr.attr.mode = 0644;
> + break;
> + case LUT_TEMP:
> + snprintf(lut->name, sizeof(lut->name),
> + "pwm1_auto_point%d_temp", i + 1);
> + sda->dev_attr.attr.mode = 0444;
> + break;
> + case LUT_HYST:
> + snprintf(lut->name, sizeof(lut->name),
> + "pwm1_auto_point%d_temp_hyst", i + 1);
> + sda->dev_attr.attr.mode = 0644;
> + break;
> + }
> +
> + sda->index = i;
> + sda->nr = nr;
> + sda->dev_attr.show = lut_show;
> + sda->dev_attr.store = lut_store;
> + sda->dev_attr.attr.name = lut->name;
> +
Call to sysfs_attr_init() is needed.
> + state->attrs[i * 3 + nr] = &sda->dev_attr.attr;
> + }
> + }
> +
> + state->group.attrs = state->attrs;
> + state->groups[0] = &state->group;
> +}
> +
> +static int max31760_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct max31760_state *state;
> + struct device *hwmon_dev;
> +
> + state = devm_kzalloc(dev, sizeof(struct max31760_state), GFP_KERNEL);
> + if (!state)
> + return -ENOMEM;
> +
> + state->regmap = devm_regmap_init_i2c(client, ®map_config);
> + if (IS_ERR(state->regmap))
> + return dev_err_probe(dev,
> + PTR_ERR(state->regmap),
> + "regmap initialization failed\n");
> +
> + dev_set_drvdata(dev, state);
> +
> + /* Set alert output to comparator mode */
> + regmap_set_bits(state->regmap, REG_CR2, CR2_ALERTS);
> +
> + max31760_create_lut_nodes(state);
> +
> + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
> + state,
> + &max31760_chip_info,
> + state->groups);
> +
> + return PTR_ERR_OR_ZERO(hwmon_dev);
> +}
> +
> +static const struct of_device_id max31760_of_match[] = {
> + {.compatible = "adi,max31760"},
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, max31760_of_match);
> +
> +static const struct i2c_device_id max31760_id[] = {
> + {"max31760"},
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, max31760_id);
> +
> +static int __maybe_unused max31760_suspend(struct device *dev)
> +{
> + struct max31760_state *state = dev_get_drvdata(dev);
> +
> + return regmap_set_bits(state->regmap, REG_CR2, CR2_STBY);
> +}
> +
> +static int __maybe_unused max31760_resume(struct device *dev)
> +{
> + struct max31760_state *state = dev_get_drvdata(dev);
> +
> + return regmap_clear_bits(state->regmap, REG_CR2, CR2_STBY);
> +}
> +
> +static SIMPLE_DEV_PM_OPS(max31760_pm_ops, max31760_suspend, max31760_resume);
> +
> +static struct i2c_driver max31760_driver = {
> + .class = I2C_CLASS_HWMON,
> + .driver = {
> + .name = "max31760",
> + .of_match_table = of_match_ptr(max31760_of_match),
> + .pm = pm_ptr(&max31760_pm_ops)
> + },
> + .probe_new = max31760_probe,
> + .id_table = max31760_id
> +};
> +module_i2c_driver(max31760_driver);
> +
> +MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Devices MAX31760 Fan Speed Controller");
> +MODULE_SOFTDEP("pre: regmap_i2c");
> +MODULE_VERSION("1.0");
> +MODULE_LICENSE("GPL");
