On Wed, Oct 09, 2019 at 12:28:05PM +0200, Nuno Sá wrote:
> The purpose of this IP Core is to control the fan used for the cooling of a
> Xilinx Zynq Ultrascale+ MPSoC without the need of any external temperature
> sensors. To achieve this, the IP core uses the PL SYSMONE4 primitive to
> obtain the PL temperature and, based on those readings, it then outputs
> a PWM signal to control the fan rotation accordingly.
>
> Signed-off-by: Nuno Sá <nuno...@analog.com>
Applied to hwmon-next.
Thanks,
Guenter
> ---
> Changes in v2:
> * define AXI_PCORE macros in the driver source for now;
> * include linux/bits.h;
> * axi_fan_control_io{read/write} renamed with shorter names;
> * Make sure tach is != 0 when getting the fan rpm;
> * Read only once the clk rate;
> * Remove unneeded struct clk;
> * Fixed typo in millidegrees;
> * Use devm_platform_ioremap_resource();
> * Remove unneeded error logs;
> * Check valid values for pulses per revolution;
> * Clear the fault attribute after reading it;
> * Notify userspace if HW changed the PWM;
> * Add comments on how the core works in other to better understand the IRQ
> handling.
>
> MAINTAINERS | 7 +
> drivers/hwmon/Kconfig | 9 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/axi-fan-control.c | 473 ++++++++++++++++++++++++++++++++
> 4 files changed, 490 insertions(+)
> create mode 100644 drivers/hwmon/axi-fan-control.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 296de2b51c83..caa80ae1925e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2873,6 +2873,13 @@ S: Maintained
> F: Documentation/devicetree/bindings/sound/axentia,*
> F: sound/soc/atmel/tse850-pcm5142.c
>
> +AXI-FAN-CONTROL HARDWARE MONITOR DRIVER
> +M: Nuno Sá <nuno...@analog.com>
> +W: http://ez.analog.com/community/linux-device-drivers
> +L: linux-hwmon@vger.kernel.org
> +S: Supported
> +F: drivers/hwmon/axi-fan-control.c
> +
> AXXIA I2C CONTROLLER
> M: Krzysztof Adamski <krzysztof.adam...@nokia.com>
> L: linux-...@vger.kernel.org
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 7b6c4025b827..ca53bb33b965 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -269,6 +269,15 @@ config SENSORS_ASC7621
> This driver can also be built as a module. If so, the module
> will be called asc7621.
>
> +config SENSORS_AXI_FAN_CONTROL
> + tristate "Analog Devices FAN Control HDL Core driver"
> + help
> + If you say yes here you get support for the Analog Devices
> + AXI HDL FAN monitoring core.
> +
> + This driver can also be built as a module. If so, the module
> + will be called axi-fan-control
> +
> config SENSORS_K8TEMP
> tristate "AMD Athlon64/FX or Opteron temperature sensor"
> depends on X86 && PCI
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 40c036ea45e6..dcb4b64e1f4d 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -51,6 +51,7 @@ obj-$(CONFIG_SENSORS_AS370) += as370-hwmon.o
> obj-$(CONFIG_SENSORS_ASC7621) += asc7621.o
> obj-$(CONFIG_SENSORS_ASPEED) += aspeed-pwm-tacho.o
> obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o
> +obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
> obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o
> obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
> obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
> diff --git a/drivers/hwmon/axi-fan-control.c b/drivers/hwmon/axi-fan-control.c
> new file mode 100644
> index 000000000000..6c1bd3269c8c
> --- /dev/null
> +++ b/drivers/hwmon/axi-fan-control.c
> @@ -0,0 +1,473 @@
> +// 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, "adi,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";
> + struct resource *res;
> + 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;
> +
> + dev_dbg(&pdev->dev, "Re-mapped from 0x%08llX to %p\n",
> + (unsigned long long)res->start, ctl->base);
> +
> + 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...@analog.com>");
> +MODULE_DESCRIPTION("Analog Devices Fan Control HDL CORE driver");
> +MODULE_LICENSE("GPL");
