diff options
Diffstat (limited to 'drivers/hwmon/axi-fan-control.c')
| -rw-r--r-- | drivers/hwmon/axi-fan-control.c | 469 |
1 files changed, 469 insertions, 0 deletions
diff --git a/drivers/hwmon/axi-fan-control.c b/drivers/hwmon/axi-fan-control.c new file mode 100644 index 000000000000..38d9cdb3db1a --- /dev/null +++ b/drivers/hwmon/axi-fan-control.c @@ -0,0 +1,469 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Fan Control HDL CORE driver + * + * Copyright 2019 Analog Devices Inc. + */ +#include <linux/bits.h> +#include <linux/clk.h> +#include <linux/fpga/adi-axi-common.h> +#include <linux/hwmon.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> + +#define ADI_AXI_PCORE_VER_MAJOR(version) (((version) >> 16) & 0xff) +#define ADI_AXI_PCORE_VER_MINOR(version) (((version) >> 8) & 0xff) +#define ADI_AXI_PCORE_VER_PATCH(version) ((version) & 0xff) + +/* register map */ +#define ADI_REG_RSTN 0x0080 +#define ADI_REG_PWM_WIDTH 0x0084 +#define ADI_REG_TACH_PERIOD 0x0088 +#define ADI_REG_TACH_TOLERANCE 0x008c +#define ADI_REG_PWM_PERIOD 0x00c0 +#define ADI_REG_TACH_MEASUR 0x00c4 +#define ADI_REG_TEMPERATURE 0x00c8 + +#define ADI_REG_IRQ_MASK 0x0040 +#define ADI_REG_IRQ_PENDING 0x0044 +#define ADI_REG_IRQ_SRC 0x0048 + +/* IRQ sources */ +#define ADI_IRQ_SRC_PWM_CHANGED BIT(0) +#define ADI_IRQ_SRC_TACH_ERR BIT(1) +#define ADI_IRQ_SRC_TEMP_INCREASE BIT(2) +#define ADI_IRQ_SRC_NEW_MEASUR BIT(3) +#define ADI_IRQ_SRC_MASK GENMASK(3, 0) +#define ADI_IRQ_MASK_OUT_ALL 0xFFFFFFFFU + +#define SYSFS_PWM_MAX 255 + +struct axi_fan_control_data { + void __iomem *base; + struct device *hdev; + unsigned long clk_rate; + int irq; + /* pulses per revolution */ + u32 ppr; + bool hw_pwm_req; + bool update_tacho_params; + u8 fan_fault; +}; + +static inline void axi_iowrite(const u32 val, const u32 reg, + const struct axi_fan_control_data *ctl) +{ + iowrite32(val, ctl->base + reg); +} + +static inline u32 axi_ioread(const u32 reg, + const struct axi_fan_control_data *ctl) +{ + return ioread32(ctl->base + reg); +} + +static long axi_fan_control_get_pwm_duty(const struct axi_fan_control_data *ctl) +{ + u32 pwm_width = axi_ioread(ADI_REG_PWM_WIDTH, ctl); + u32 pwm_period = axi_ioread(ADI_REG_PWM_PERIOD, ctl); + /* + * PWM_PERIOD is a RO register set by the core. It should never be 0. + * For now we are trusting the HW... + */ + return DIV_ROUND_CLOSEST(pwm_width * SYSFS_PWM_MAX, pwm_period); +} + +static int axi_fan_control_set_pwm_duty(const long val, + struct axi_fan_control_data *ctl) +{ + u32 pwm_period = axi_ioread(ADI_REG_PWM_PERIOD, ctl); + u32 new_width; + long __val = clamp_val(val, 0, SYSFS_PWM_MAX); + + new_width = DIV_ROUND_CLOSEST(__val * pwm_period, SYSFS_PWM_MAX); + + axi_iowrite(new_width, ADI_REG_PWM_WIDTH, ctl); + + return 0; +} + +static long axi_fan_control_get_fan_rpm(const struct axi_fan_control_data *ctl) +{ + const u32 tach = axi_ioread(ADI_REG_TACH_MEASUR, ctl); + + if (tach == 0) + /* should we return error, EAGAIN maybe? */ + return 0; + /* + * The tacho period should be: + * TACH = 60/(ppr * rpm), where rpm is revolutions per second + * and ppr is pulses per revolution. + * Given the tacho period, we can multiply it by the input clock + * so that we know how many clocks we need to have this period. + * From this, we can derive the RPM value. + */ + return DIV_ROUND_CLOSEST(60 * ctl->clk_rate, ctl->ppr * tach); +} + +static int axi_fan_control_read_temp(struct device *dev, u32 attr, long *val) +{ + struct axi_fan_control_data *ctl = dev_get_drvdata(dev); + long raw_temp; + + switch (attr) { + case hwmon_temp_input: + raw_temp = axi_ioread(ADI_REG_TEMPERATURE, ctl); + /* + * The formula for the temperature is: + * T = (ADC * 501.3743 / 2^bits) - 273.6777 + * It's multiplied by 1000 to have millidegrees as + * specified by the hwmon sysfs interface. + */ + *val = ((raw_temp * 501374) >> 16) - 273677; + return 0; + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_read_fan(struct device *dev, u32 attr, long *val) +{ + struct axi_fan_control_data *ctl = dev_get_drvdata(dev); + + switch (attr) { + case hwmon_fan_fault: + *val = ctl->fan_fault; + /* clear it now */ + ctl->fan_fault = 0; + return 0; + case hwmon_fan_input: + *val = axi_fan_control_get_fan_rpm(ctl); + return 0; + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_read_pwm(struct device *dev, u32 attr, long *val) +{ + struct axi_fan_control_data *ctl = dev_get_drvdata(dev); + + switch (attr) { + case hwmon_pwm_input: + *val = axi_fan_control_get_pwm_duty(ctl); + return 0; + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_write_pwm(struct device *dev, u32 attr, long val) +{ + struct axi_fan_control_data *ctl = dev_get_drvdata(dev); + + switch (attr) { + case hwmon_pwm_input: + return axi_fan_control_set_pwm_duty(val, ctl); + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_read_labels(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + switch (type) { + case hwmon_fan: + *str = "FAN"; + return 0; + case hwmon_temp: + *str = "SYSMON4"; + return 0; + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_read(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + switch (type) { + case hwmon_fan: + return axi_fan_control_read_fan(dev, attr, val); + case hwmon_pwm: + return axi_fan_control_read_pwm(dev, attr, val); + case hwmon_temp: + return axi_fan_control_read_temp(dev, attr, val); + default: + return -ENOTSUPP; + } +} + +static int axi_fan_control_write(struct device *dev, + enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + switch (type) { + case hwmon_pwm: + return axi_fan_control_write_pwm(dev, attr, val); + default: + return -ENOTSUPP; + } +} + +static umode_t axi_fan_control_fan_is_visible(const u32 attr) +{ + switch (attr) { + case hwmon_fan_input: + case hwmon_fan_fault: + case hwmon_fan_label: + return 0444; + default: + return 0; + } +} + +static umode_t axi_fan_control_pwm_is_visible(const u32 attr) +{ + switch (attr) { + case hwmon_pwm_input: + return 0644; + default: + return 0; + } +} + +static umode_t axi_fan_control_temp_is_visible(const u32 attr) +{ + switch (attr) { + case hwmon_temp_input: + case hwmon_temp_label: + return 0444; + default: + return 0; + } +} + +static umode_t axi_fan_control_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + switch (type) { + case hwmon_fan: + return axi_fan_control_fan_is_visible(attr); + case hwmon_pwm: + return axi_fan_control_pwm_is_visible(attr); + case hwmon_temp: + return axi_fan_control_temp_is_visible(attr); + default: + return 0; + } +} + +/* + * This core has two main ways of changing the PWM duty cycle. It is done, + * either by a request from userspace (writing on pwm1_input) or by the + * core itself. When the change is done by the core, it will use predefined + * parameters to evaluate the tach signal and, on that case we cannot set them. + * On the other hand, when the request is done by the user, with some arbitrary + * value that the core does not now about, we have to provide the tach + * parameters so that, the core can evaluate the signal. On the IRQ handler we + * distinguish this by using the ADI_IRQ_SRC_TEMP_INCREASE interrupt. This tell + * us that the CORE requested a new duty cycle. After this, there is 5s delay + * on which the core waits for the fan rotation speed to stabilize. After this + * we get ADI_IRQ_SRC_PWM_CHANGED irq where we will decide if we need to set + * the tach parameters or not on the next tach measurement cycle (corresponding + * already to the ney duty cycle) based on the %ctl->hw_pwm_req flag. + */ +static irqreturn_t axi_fan_control_irq_handler(int irq, void *data) +{ + struct axi_fan_control_data *ctl = (struct axi_fan_control_data *)data; + u32 irq_pending = axi_ioread(ADI_REG_IRQ_PENDING, ctl); + u32 clear_mask; + + if (irq_pending & ADI_IRQ_SRC_NEW_MEASUR) { + if (ctl->update_tacho_params) { + u32 new_tach = axi_ioread(ADI_REG_TACH_MEASUR, ctl); + + /* get 25% tolerance */ + u32 tach_tol = DIV_ROUND_CLOSEST(new_tach * 25, 100); + /* set new tacho parameters */ + axi_iowrite(new_tach, ADI_REG_TACH_PERIOD, ctl); + axi_iowrite(tach_tol, ADI_REG_TACH_TOLERANCE, ctl); + ctl->update_tacho_params = false; + } + } + + if (irq_pending & ADI_IRQ_SRC_PWM_CHANGED) { + /* + * if the pwm changes on behalf of software, + * we need to provide new tacho parameters to the core. + * Wait for the next measurement for that... + */ + if (!ctl->hw_pwm_req) { + ctl->update_tacho_params = true; + } else { + ctl->hw_pwm_req = false; + sysfs_notify(&ctl->hdev->kobj, NULL, "pwm1"); + } + } + + if (irq_pending & ADI_IRQ_SRC_TEMP_INCREASE) + /* hardware requested a new pwm */ + ctl->hw_pwm_req = true; + + if (irq_pending & ADI_IRQ_SRC_TACH_ERR) + ctl->fan_fault = 1; + + /* clear all interrupts */ + clear_mask = irq_pending & ADI_IRQ_SRC_MASK; + axi_iowrite(clear_mask, ADI_REG_IRQ_PENDING, ctl); + + return IRQ_HANDLED; +} + +static int axi_fan_control_init(struct axi_fan_control_data *ctl, + const struct device_node *np) +{ + int ret; + + /* get fan pulses per revolution */ + ret = of_property_read_u32(np, "pulses-per-revolution", &ctl->ppr); + if (ret) + return ret; + + /* 1, 2 and 4 are the typical and accepted values */ + if (ctl->ppr != 1 && ctl->ppr != 2 && ctl->ppr != 4) + return -EINVAL; + /* + * Enable all IRQs + */ + axi_iowrite(ADI_IRQ_MASK_OUT_ALL & + ~(ADI_IRQ_SRC_NEW_MEASUR | ADI_IRQ_SRC_TACH_ERR | + ADI_IRQ_SRC_PWM_CHANGED | ADI_IRQ_SRC_TEMP_INCREASE), + ADI_REG_IRQ_MASK, ctl); + + /* bring the device out of reset */ + axi_iowrite(0x01, ADI_REG_RSTN, ctl); + + return ret; +} + +static const struct hwmon_channel_info *axi_fan_control_info[] = { + HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT), + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_LABEL), + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_LABEL), + NULL +}; + +static const struct hwmon_ops axi_fan_control_hwmon_ops = { + .is_visible = axi_fan_control_is_visible, + .read = axi_fan_control_read, + .write = axi_fan_control_write, + .read_string = axi_fan_control_read_labels, +}; + +static const struct hwmon_chip_info axi_chip_info = { + .ops = &axi_fan_control_hwmon_ops, + .info = axi_fan_control_info, +}; + +static const u32 version_1_0_0 = ADI_AXI_PCORE_VER(1, 0, 'a'); + +static const struct of_device_id axi_fan_control_of_match[] = { + { .compatible = "adi,axi-fan-control-1.00.a", + .data = (void *)&version_1_0_0}, + {}, +}; +MODULE_DEVICE_TABLE(of, axi_fan_control_of_match); + +static int axi_fan_control_probe(struct platform_device *pdev) +{ + struct axi_fan_control_data *ctl; + struct clk *clk; + const struct of_device_id *id; + const char *name = "axi_fan_control"; + u32 version; + int ret; + + id = of_match_node(axi_fan_control_of_match, pdev->dev.of_node); + if (!id) + return -EINVAL; + + ctl = devm_kzalloc(&pdev->dev, sizeof(*ctl), GFP_KERNEL); + if (!ctl) + return -ENOMEM; + + ctl->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(ctl->base)) + return PTR_ERR(ctl->base); + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "clk_get failed with %ld\n", PTR_ERR(clk)); + return PTR_ERR(clk); + } + + ctl->clk_rate = clk_get_rate(clk); + if (!ctl->clk_rate) + return -EINVAL; + + version = axi_ioread(ADI_AXI_REG_VERSION, ctl); + if (ADI_AXI_PCORE_VER_MAJOR(version) != + ADI_AXI_PCORE_VER_MAJOR((*(u32 *)id->data))) { + dev_err(&pdev->dev, "Major version mismatch. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n", + ADI_AXI_PCORE_VER_MAJOR((*(u32 *)id->data)), + ADI_AXI_PCORE_VER_MINOR((*(u32 *)id->data)), + ADI_AXI_PCORE_VER_PATCH((*(u32 *)id->data)), + ADI_AXI_PCORE_VER_MAJOR(version), + ADI_AXI_PCORE_VER_MINOR(version), + ADI_AXI_PCORE_VER_PATCH(version)); + return -ENODEV; + } + + ctl->irq = platform_get_irq(pdev, 0); + if (ctl->irq < 0) + return ctl->irq; + + ret = devm_request_threaded_irq(&pdev->dev, ctl->irq, NULL, + axi_fan_control_irq_handler, + IRQF_ONESHOT | IRQF_TRIGGER_HIGH, + pdev->driver_override, ctl); + if (ret) { + dev_err(&pdev->dev, "failed to request an irq, %d", ret); + return ret; + } + + ret = axi_fan_control_init(ctl, pdev->dev.of_node); + if (ret) { + dev_err(&pdev->dev, "Failed to initialize device\n"); + return ret; + } + + ctl->hdev = devm_hwmon_device_register_with_info(&pdev->dev, + name, + ctl, + &axi_chip_info, + NULL); + + return PTR_ERR_OR_ZERO(ctl->hdev); +} + +static struct platform_driver axi_fan_control_driver = { + .driver = { + .name = "axi_fan_control_driver", + .of_match_table = axi_fan_control_of_match, + }, + .probe = axi_fan_control_probe, +}; +module_platform_driver(axi_fan_control_driver); + +MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>"); +MODULE_DESCRIPTION("Analog Devices Fan Control HDL CORE driver"); +MODULE_LICENSE("GPL"); |