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path: root/drivers/hwmon/axi-fan-control.c
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Diffstat (limited to 'drivers/hwmon/axi-fan-control.c')
-rw-r--r--drivers/hwmon/axi-fan-control.c469
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");
generated by cgit (git 2.34.1) at 2024-05-02 07:07:17 +0000