diff options
Diffstat (limited to 'drivers/hwmon/kfan.c')
| -rw-r--r-- | drivers/hwmon/kfan.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/drivers/hwmon/kfan.c b/drivers/hwmon/kfan.c new file mode 100644 index 000000000000..f353acb66749 --- /dev/null +++ b/drivers/hwmon/kfan.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2025 KEBA Industrial Automation GmbH + * + * Driver for KEBA fan controller FPGA IP core + * + */ + +#include <linux/hwmon.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/auxiliary_bus.h> +#include <linux/misc/keba.h> + +#define KFAN "kfan" + +#define KFAN_CONTROL_REG 0x04 + +#define KFAN_STATUS_REG 0x08 +#define KFAN_STATUS_PRESENT 0x01 +#define KFAN_STATUS_REGULABLE 0x02 +#define KFAN_STATUS_TACHO 0x04 +#define KFAN_STATUS_BLOCKED 0x08 + +#define KFAN_TACHO_REG 0x0c + +#define KFAN_DEFAULT_DIV 2 + +struct kfan { + void __iomem *base; + bool tacho; + bool regulable; + + /* hwmon API configuration */ + u32 fan_channel_config[2]; + struct hwmon_channel_info fan_info; + u32 pwm_channel_config[2]; + struct hwmon_channel_info pwm_info; + const struct hwmon_channel_info *info[3]; + struct hwmon_chip_info chip; +}; + +static bool kfan_get_fault(struct kfan *kfan) +{ + u8 status = ioread8(kfan->base + KFAN_STATUS_REG); + + if (!(status & KFAN_STATUS_PRESENT)) + return true; + + if (!kfan->tacho && (status & KFAN_STATUS_BLOCKED)) + return true; + + return false; +} + +static unsigned int kfan_count_to_rpm(u16 count) +{ + if (count == 0 || count == 0xffff) + return 0; + + return 5000000UL / (KFAN_DEFAULT_DIV * count); +} + +static unsigned int kfan_get_rpm(struct kfan *kfan) +{ + unsigned int rpm; + u16 count; + + count = ioread16(kfan->base + KFAN_TACHO_REG); + rpm = kfan_count_to_rpm(count); + + return rpm; +} + +static unsigned int kfan_get_pwm(struct kfan *kfan) +{ + return ioread8(kfan->base + KFAN_CONTROL_REG); +} + +static int kfan_set_pwm(struct kfan *kfan, long val) +{ + if (val < 0 || val > 0xff) + return -EINVAL; + + /* if none-regulable, then only 0 or 0xff can be written */ + if (!kfan->regulable && val > 0) + val = 0xff; + + iowrite8(val, kfan->base + KFAN_CONTROL_REG); + + return 0; +} + +static int kfan_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct kfan *kfan = dev_get_drvdata(dev); + + switch (type) { + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + return kfan_set_pwm(kfan, val); + default: + break; + } + break; + default: + break; + } + + return -EOPNOTSUPP; +} + +static int kfan_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct kfan *kfan = dev_get_drvdata(dev); + + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_fault: + *val = kfan_get_fault(kfan); + return 0; + case hwmon_fan_input: + *val = kfan_get_rpm(kfan); + return 0; + default: + break; + } + break; + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + *val = kfan_get_pwm(kfan); + return 0; + default: + break; + } + break; + default: + break; + } + + return -EOPNOTSUPP; +} + +static umode_t kfan_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + return 0444; + case hwmon_fan_fault: + return 0444; + default: + break; + } + break; + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + return 0644; + default: + break; + } + break; + default: + break; + } + + return 0; +} + +static const struct hwmon_ops kfan_hwmon_ops = { + .is_visible = kfan_is_visible, + .read = kfan_read, + .write = kfan_write, +}; + +static int kfan_probe(struct auxiliary_device *auxdev, + const struct auxiliary_device_id *id) +{ + struct keba_fan_auxdev *kfan_auxdev = + container_of(auxdev, struct keba_fan_auxdev, auxdev); + struct device *dev = &auxdev->dev; + struct device *hwmon_dev; + struct kfan *kfan; + u8 status; + + kfan = devm_kzalloc(dev, sizeof(*kfan), GFP_KERNEL); + if (!kfan) + return -ENOMEM; + + kfan->base = devm_ioremap_resource(dev, &kfan_auxdev->io); + if (IS_ERR(kfan->base)) + return PTR_ERR(kfan->base); + + status = ioread8(kfan->base + KFAN_STATUS_REG); + if (status & KFAN_STATUS_REGULABLE) + kfan->regulable = true; + if (status & KFAN_STATUS_TACHO) + kfan->tacho = true; + + /* fan */ + kfan->fan_channel_config[0] = HWMON_F_FAULT; + if (kfan->tacho) + kfan->fan_channel_config[0] |= HWMON_F_INPUT; + kfan->fan_info.type = hwmon_fan; + kfan->fan_info.config = kfan->fan_channel_config; + kfan->info[0] = &kfan->fan_info; + + /* PWM */ + kfan->pwm_channel_config[0] = HWMON_PWM_INPUT; + kfan->pwm_info.type = hwmon_pwm; + kfan->pwm_info.config = kfan->pwm_channel_config; + kfan->info[1] = &kfan->pwm_info; + + kfan->chip.ops = &kfan_hwmon_ops; + kfan->chip.info = kfan->info; + hwmon_dev = devm_hwmon_device_register_with_info(dev, KFAN, kfan, + &kfan->chip, NULL); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct auxiliary_device_id kfan_devtype_aux[] = { + { .name = "keba.fan" }, + {} +}; +MODULE_DEVICE_TABLE(auxiliary, kfan_devtype_aux); + +static struct auxiliary_driver kfan_driver_aux = { + .name = KFAN, + .id_table = kfan_devtype_aux, + .probe = kfan_probe, +}; +module_auxiliary_driver(kfan_driver_aux); + +MODULE_AUTHOR("Petar Bojanic <boja@keba.com>"); +MODULE_AUTHOR("Gerhard Engleder <eg@keba.com>"); +MODULE_DESCRIPTION("KEBA fan controller driver"); +MODULE_LICENSE("GPL"); |