[PATCH linux dev-4.10] hwmon: (aspeed-pwm-tacho) cooling device support

Patrick Venture venture at google.com
Thu Jul 6 06:49:47 AEST 2017


On Wed, Jul 5, 2017 at 1:10 PM, Vadim Pasternak <vadimp at mellanox.com> wrote:
>
>
>> -----Original Message-----
>> From: openbmc [mailto:openbmc-
>> bounces+yanivab=mellanox.com at lists.ozlabs.org] On Behalf Of Patrick
>> Venture
>> Sent: Wednesday, July 05, 2017 10:42 PM
>> To: Mykola Kostenok <c_mykolak at mellanox.com>
>> Cc: OpenBMC Maillist <openbmc at lists.ozlabs.org>
>> Subject: Re: [PATCH linux dev-4.10] hwmon: (aspeed-pwm-tacho) cooling
>> device support
>>
>> On Tue, Jul 4, 2017 at 6:56 AM, Mykola Kostenok
>> <c_mykolak at mellanox.com> wrote:
>> > Add support in aspeed-pwm-tacho driver for cooling device creation.
>> > This cooling device could be bound to a thermal zone for the thermal
>> > control. Device will appear in /sys/class/thermal folder as
>> > cooling_deviceX. Then it could be bound to particular thermal zones.
>> > Allow specification of the cooling levels vector - PWM duty cycle
>> > values in a range from 0 to 255 which correspond to thermal cooling
>> > states.
>> >
>> > Add basic pwm-tacho-controller node to ast-g5 dtsi.
>> > Add basic pwm-tacho-controller node to ast-g4 dtsi.
>> >
>> > Change pwm-tacho in aspeed-bmc-quanta-q71l.dts according new pwm-
>> tacho
>> > structure.
>> >
>> > Add pwm-tacho to aspeed-bmc-mellanox-msn.dts.
>> >
>> > Signed-off-by: Mykola Kostenok <c_mykolak at mellanox.com>
>> > ---
>> >  arch/arm/boot/dts/aspeed-bmc-mellanox-msn.dts |  61 +++++++++++
>> > arch/arm/boot/dts/aspeed-bmc-quanta-q71l.dts  | 103 +++++++++---------
>> -
>> >  arch/arm/boot/dts/aspeed-g4.dtsi              |   9 +-
>> >  arch/arm/boot/dts/aspeed-g5.dtsi              |  17 ++++
>> >  drivers/hwmon/aspeed-pwm-tacho.c              | 139
>> +++++++++++++++++++++++++-
>> >  5 files changed, 273 insertions(+), 56 deletions(-)
>> >
>> > diff --git a/arch/arm/boot/dts/aspeed-bmc-mellanox-msn.dts
>> > b/arch/arm/boot/dts/aspeed-bmc-mellanox-msn.dts
>> > index c71a6db..57d5951 100644
>> > --- a/arch/arm/boot/dts/aspeed-bmc-mellanox-msn.dts
>> > +++ b/arch/arm/boot/dts/aspeed-bmc-mellanox-msn.dts
>> > @@ -144,3 +144,64 @@
>> >         status = "okay";
>> >  };
>> >
>> > +&pwm_tacho {
>> > +       status = "okay";
>> > +       pinctrl-names = "default";
>> > +       pinctrl-0 = <&pinctrl_pwm0_default>;
>> > +
>> > +       tach-channels {
>> > +               #address-cells = <1>;
>> > +               #size-cells = <0>;
>> > +
>> > +               fan at 0 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x00>;
>> > +               };
>> > +
>> > +               fan at 1 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x01>;
>> > +               };
>> > +
>> > +               fan at 2 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x02>;
>> > +               };
>> > +
>> > +               fan at 3 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x03>;
>> > +               };
>> > +
>> > +               fan at 4 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x04>;
>> > +               };
>> > +
>> > +               fan at 5 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x05>;
>> > +               };
>> > +
>> > +               fan at 6 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x06>;
>> > +               };
>> > +
>> > +               fan at 7 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x07>;
>> > +               };
>> > +       };
>> > +
>> > +       pwm-channels {
>> > +               #address-cells = <1>;
>> > +               #size-cells = <0>;
>> > +               #cooling-cells = <2>;
>> > +
>> > +               pwm at 0 {
>> > +                       reg = <0x00>;
>> > +                       cooling-levels = /bits/ 8 <125 151 177 203 229 255>;
>> > +               };
>> > +       };
>> > +};
>> > diff --git a/arch/arm/boot/dts/aspeed-bmc-quanta-q71l.dts
>> > b/arch/arm/boot/dts/aspeed-bmc-quanta-q71l.dts
>> > index bb287fb..43ada5b 100644
>> > --- a/arch/arm/boot/dts/aspeed-bmc-quanta-q71l.dts
>> > +++ b/arch/arm/boot/dts/aspeed-bmc-quanta-q71l.dts
>> > @@ -46,57 +46,6 @@
>> >                         gpios = <&gpio ASPEED_GPIO(B, 3) GPIO_ACTIVE_LOW>;
>> >                 };
>> >         };
>> > -
>> > -       pwm_tacho: pwm-tacho-controller at 1e786000 {
>> > -               compatible = "aspeed,ast2500-pwm-tacho";
>> > -               #address-cells = <1>;
>> > -               #size-cells = <0>;
>> > -               reg = <0x1e786000 0x1000>;
>> > -               clocks = <&pwm_tacho_fixed_clk>;
>> > -               pinctrl-names = "default";
>> > -               pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default
>> > -                       &pinctrl_pwm2_default &pinctrl_pwm3_default>;
>> > -
>> > -               fan at 0 {
>> > -                       reg = <0x00>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x00>;
>> > -               };
>> > -
>> > -               fan at 1 {
>> > -                       reg = <0x01>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x01>;
>> > -               };
>> > -
>> > -               fan at 2 {
>> > -                       reg = <0x02>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x02>;
>> > -               };
>> > -
>> > -               fan at 3 {
>> > -                       reg = <0x03>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x03>;
>> > -               };
>> > -
>> > -               fan at 4 {
>> > -                       reg = <0x00>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x04>;
>> > -               };
>> > -
>> > -               fan at 5 {
>> > -                       reg = <0x01>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x05>;
>> > -               };
>> > -
>> > -               fan at 6 {
>> > -                       reg = <0x02>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x06>;
>> > -               };
>> > -
>> > -               fan at 7 {
>> > -                       reg = <0x03>;
>> > -                       aspeed,fan-tach-ch = /bits/ 8 <0x07>;
>> > -               };
>> > -       };
>> >  };
>> >
>> >  &fmc {
>> > @@ -299,3 +248,55 @@
>> >  &wdt2 {
>> >         status = "okay";
>> >  };
>> > +
>> > +&pwm_tacho {
>> > +       status = "okay";
>> > +       pinctrl-names = "default";
>> > +       pinctrl-0 = <&pinctrl_pwm0_default &pinctrl_pwm1_default
>> > +                               &pinctrl_pwm2_default
>> > +&pinctrl_pwm3_default>;
>> > +
>> > +       tach-channels {
>> > +               #address-cells = <1>;
>> > +               #size-cells = <0>;
>> > +
>> > +               fan at 0 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x00>;
>> > +               };
>> > +
>> > +               fan at 1 {
>> > +                       reg = <0x01>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x01>;
>> > +               };
>> > +
>> > +               fan at 2 {
>> > +                       reg = <0x02>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x02>;
>> > +               };
>> > +
>> > +               fan at 3 {
>> > +                       reg = <0x03>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x03>;
>> > +               };
>> > +
>> > +               fan at 4 {
>> > +                       reg = <0x00>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x04>;
>> > +               };
>> > +
>> > +               fan at 5 {
>> > +                       reg = <0x01>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x05>;
>> > +               };
>> > +
>> > +               fan at 6 {
>> > +                       reg = <0x02>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x06>;
>> > +               };
>> > +
>> > +               fan at 7 {
>> > +                       reg = <0x03>;
>> > +                       aspeed,fan-tach-ch = /bits/ 8 <0x07>;
>> > +               };
>> > +       };
>> > +};
>> > diff --git a/arch/arm/boot/dts/aspeed-g4.dtsi
>> > b/arch/arm/boot/dts/aspeed-g4.dtsi
>> > index 9cc959f..c69ad77 100644
>> > --- a/arch/arm/boot/dts/aspeed-g4.dtsi
>> > +++ b/arch/arm/boot/dts/aspeed-g4.dtsi
>> > @@ -318,7 +318,14 @@
>> >                                 ranges = <0 0x1e78a000 0x1000>;
>> >                         };
>> >
>> > -
>> > +                       pwm_tacho: pwm-tacho-controller at 1e786000 {
>> > +                               compatible = "aspeed,ast2500-pwm-tacho";
>> > +                               #address-cells = <1>;
>> > +                               #size-cells = <0>;
>> > +                               reg = <0x1e786000 0x1000>;
>> > +                               clocks = <&pwm_tacho_fixed_clk>;
>> > +                               status = "disabled";
>> > +                       };
>> >                 };
>> >         };
>> >  };
>> > diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi
>> > b/arch/arm/boot/dts/aspeed-g5.dtsi
>> > index 992242d..1ed29d9 100644
>> > --- a/arch/arm/boot/dts/aspeed-g5.dtsi
>> > +++ b/arch/arm/boot/dts/aspeed-g5.dtsi
>> > @@ -35,6 +35,14 @@
>> >                 i2c13 = &i2c13;
>> >         };
>> >
>> > +       clocks {
>> > +               pwm_tacho_fixed_clk: fixedclk {
>> > +                       compatible = "fixed-clock";
>> > +                       #clock-cells = <0>;
>> > +                       clock-frequency = <24000000>;
>> > +               };
>> > +       };
>> > +
>> >         ahb {
>> >                 compatible = "simple-bus";
>> >                 #address-cells = <1>;
>> > @@ -366,6 +374,15 @@
>> >                                 #size-cells = <1>;
>> >                                 ranges = <0 0x1e78a000 0x1000>;
>> >                         };
>> > +
>> > +                       pwm_tacho: pwm-tacho-controller at 1e786000 {
>> > +                               compatible = "aspeed,ast2500-pwm-tacho";
>> > +                               #address-cells = <1>;
>> > +                               #size-cells = <0>;
>> > +                               reg = <0x1e786000 0x1000>;
>> > +                               clocks = <&pwm_tacho_fixed_clk>;
>> > +                               status = "disabled";
>> > +                       };
>> >                 };
>> >         };
>> >  };
>> > diff --git a/drivers/hwmon/aspeed-pwm-tacho.c
>> > b/drivers/hwmon/aspeed-pwm-tacho.c
>> > index ddfe66b..eab18af 100644
>> > --- a/drivers/hwmon/aspeed-pwm-tacho.c
>> > +++ b/drivers/hwmon/aspeed-pwm-tacho.c
>> > @@ -20,6 +20,7 @@
>> >  #include <linux/platform_device.h>
>> >  #include <linux/sysfs.h>
>> >  #include <linux/regmap.h>
>> > +#include <linux/thermal.h>
>> >
>> >  /* ASPEED PWM & FAN Tach Register Definition */
>> >  #define ASPEED_PTCR_CTRL               0x00
>> > @@ -166,6 +167,16 @@
>> >  /* How long we sleep in us while waiting for an RPM result. */
>> >  #define ASPEED_RPM_STATUS_SLEEP_USEC   500
>> >
>> > +struct aspeed_cooling_device {
>> > +       char name[16];
>> > +       struct aspeed_pwm_tacho_data *priv;
>> > +       struct thermal_cooling_device *tcdev;
>> > +       int pwm_port;
>> > +       u8 *cooling_levels;
>> > +       u8 max_state;
>> > +       u8 cur_state;
>> > +};
>> > +
>> >  struct aspeed_pwm_tacho_data {
>> >         struct regmap *regmap;
>> >         unsigned long clk_freq;
>> > @@ -180,6 +191,7 @@ struct aspeed_pwm_tacho_data {
>> >         u8 pwm_port_type[8];
>> >         u8 pwm_port_fan_ctrl[8];
>> >         u8 fan_tach_ch_source[16];
>> > +       struct aspeed_cooling_device *cdev[8];
>> >         const struct attribute_group *groups[3];  };
>> >
>> > @@ -794,10 +806,111 @@ static int aspeed_create_fan(struct device *dev,
>> >         return 0;
>> >  }
>> >
>> > +static int
>> > +aspeed_pwm_cz_get_max_state(struct thermal_cooling_device *tcdev,
>> > +                           unsigned long *state) {
>> > +       struct aspeed_cooling_device *cdev =
>> > +                               (struct aspeed_cooling_device
>> > +*)tcdev->devdata;
>> > +
>> > +       *state = cdev->max_state;
>> > +
>> > +       return 0;
>> > +}
>> > +
>> > +static int
>> > +aspeed_pwm_cz_get_cur_state(struct thermal_cooling_device *tcdev,
>> > +                           unsigned long *state) {
>> > +       struct aspeed_cooling_device *cdev =
>> > +                               (struct aspeed_cooling_device
>> > +*)tcdev->devdata;
>> > +
>> > +       *state = cdev->cur_state;
>> > +
>> > +       return 0;
>> > +}
>> > +
>> > +static int
>> > +aspeed_pwm_cz_set_cur_state(struct thermal_cooling_device *tcdev,
>> > +                           unsigned long state) {
>> > +       struct aspeed_cooling_device *cdev =
>> > +                               (struct aspeed_cooling_device
>> > +*)tcdev->devdata;
>> > +
>> > +       if (state > cdev->max_state)
>> > +               return -EINVAL;
>> > +
>> > +       cdev->cur_state = state;
>> > +       cdev->priv->pwm_port_fan_ctrl[cdev->pwm_port] = *(cdev-
>> >cooling_levels
>> > +                                                         + cdev->cur_state);
>> > +       aspeed_set_pwm_port_fan_ctrl(cdev->priv, cdev->pwm_port,
>> > +                                    *(cdev->cooling_levels +
>> > +                                      cdev->cur_state));
>> > +
>> > +       return 0;
>> > +}
>> > +
>> > +static const struct thermal_cooling_device_ops aspeed_pwm_cool_ops =
>> {
>> > +       .get_max_state = aspeed_pwm_cz_get_max_state,
>> > +       .get_cur_state = aspeed_pwm_cz_get_cur_state,
>> > +       .set_cur_state = aspeed_pwm_cz_set_cur_state, };
>> > +
>> > +static int aspeed_create_pwm(struct device *dev,
>> > +                            struct device_node *child,
>> > +                            struct aspeed_pwm_tacho_data *priv)
>>
>> For this, I would recommend just renaming to aspeed_create_pwm_cooling
>>
>> > +{
>> > +       u32 pwm_port;
>> > +       int ret;
>> > +
>> > +       ret = of_property_read_u32(child, "reg", &pwm_port);
>> > +       if (ret)
>> > +               return ret;
>> > +
>> > +       ret = of_property_count_u8_elems(child, "cooling-levels");
>> > +       if (ret <= 0) {
>> > +               dev_err(dev, "Wrong cooling-levels data.\n");
>> > +               return -EINVAL;
>> > +       }
>> > +
>> > +       priv->cdev[pwm_port] = devm_kzalloc(dev, sizeof(*priv-
>> >cdev[pwm_port]),
>> > +                                           GFP_KERNEL);
>> > +       if (!priv->cdev[pwm_port])
>> > +               return -ENOMEM;
>> > +
>> > +       priv->cdev[pwm_port]->cooling_levels = devm_kzalloc(dev, ret *
>> > +                                                           sizeof(u8),
>> > +                                                           GFP_KERNEL);
>> > +       if (!priv->cdev[pwm_port]->cooling_levels)
>> > +               return -ENOMEM;
>> > +
>> > +       priv->cdev[pwm_port]->max_state = ret - 1;
>> > +       ret = of_property_read_u8_array(child, "cooling-levels",
>> > +                                       priv->cdev[pwm_port]->cooling_levels,
>> > +                                       ret);
>> > +       if (ret) {
>> > +               dev_err(dev, "Property 'cooling-levels' cannot be read.\n");
>> > +               return ret;
>> > +       }
>> > +
>> > +       sprintf(priv->cdev[pwm_port]->name, "%s%d", child->name,
>> pwm_port);
>> > +       priv->cdev[pwm_port]->tcdev =
>> thermal_of_cooling_device_register(child,
>> > +                                               priv->cdev[pwm_port]->name,
>> > +                                               priv->cdev[pwm_port],
>> > +                                               &aspeed_pwm_cool_ops);
>> > +       if (PTR_ERR_OR_ZERO(priv->cdev[pwm_port]->tcdev))
>> > +               return PTR_ERR(priv->cdev[pwm_port]->tcdev);
>> > +
>> > +       priv->cdev[pwm_port]->priv = priv;
>> > +       priv->cdev[pwm_port]->pwm_port = pwm_port;
>> > +
>> > +       return 0;
>> > +}
>> > +
>> >  static int aspeed_pwm_tacho_probe(struct platform_device *pdev)  {
>> >         struct device *dev = &pdev->dev;
>> > -       struct device_node *np, *child;
>> > +       struct device_node *np, *child, *grandchild;
>> >         struct aspeed_pwm_tacho_data *priv;
>> >         void __iomem *regs;
>> >         struct resource *res;
>> > @@ -833,10 +946,28 @@ static int aspeed_pwm_tacho_probe(struct
>> platform_device *pdev)
>> >         aspeed_create_type(priv);
>> >
>> >         for_each_child_of_node(np, child) {
>> > -               ret = aspeed_create_fan(dev, child, priv);
>> > +               if (!of_node_cmp(child->name, "tach-channels")) {
>> > +                       for_each_child_of_node(child, grandchild) {
>> > +                               ret = aspeed_create_fan(dev, grandchild, priv);
>> > +                               of_node_put(grandchild);
>> > +                               if (ret) {
>> > +                                       of_node_put(child);
>> > +                                       return ret;
>> > +                               }
>> > +                       }
>> > +               }
>> > +
>> > +               if (!of_node_cmp(child->name, "pwm-channels")) {
>> > +                       for_each_child_of_node(child, grandchild) {
>> > +                               ret = aspeed_create_pwm(dev, grandchild, priv);
>> > +                               of_node_put(grandchild);
>> > +                               if (ret) {
>> > +                                       of_node_put(child);
>> > +                                       return ret;
>> > +                               }
>> > +                       }
>> > +               }
>> >                 of_node_put(child);
>> > -               if (ret)
>> > -                       return ret;
>> >         }
>> >
>> >         priv->groups[0] = &pwm_dev_group;
>> > --
>> > 2.8.4
>> >
>>
>> Presumably it's been tested and won't impact users who don't configure this
>> behaviour, so I don't have a lot of feedback about functionality.
>
> Hi Patrick,
>
> Thanks for review.
>
> If it's not configured, cooling device is not created and of course there is no impact of functionality.
> If cooling device is created, but not bound to any thermal device there is also no impact.
>
> We are using it along with kernel step wise thermal algorithm which  is supposed to set up or down pwm on crossing thermal zone boundary to the relevant cooling level and to perform PWM throttling  according to temperature trend.
> It also can be enabled/disabled through sysfs.
>
> Cheers,
> Vadim.

Fantastic.  I approve this change.  Have you sent this driver patch
upstream to hwmon maintainers?

Patrick


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