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