Re: [PATCH v4 2/4] thermal: add brcmstb AVS TMON driver

Zhang Rui
2017-08-15T06:08:37Z

On Wed, 2017-08-09 at 15:02 -0700, Markus Mayer wrote:
> From: Brian Norris <computersforpeace@gmail.com>
>
> The AVS TMON core provides temperature readings, a pair of
> configurable
> high- and low-temperature threshold interrupts, and an emergency
> over-temperature chip reset. The driver utilizes the first two to
> provide temperature readings and high-temperature notifications to
> applications. The over-temperature reset is not exposed to
> applications; this reset threshold is critical to the system and
> should
> be set with care within the bootloader.
>
> Applications may choose to utilize the notification mechanism, the
> temperature reading mechanism (e.g., through polling), or both.
>
> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> Signed-off-by: Doug Berger <opendmb@gmail.com>
> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
> ---
>  drivers/thermal/Kconfig                    |   2 +-
>  drivers/thermal/broadcom/Kconfig           |   7 +
>  drivers/thermal/broadcom/Makefile          |   1 +
>  drivers/thermal/broadcom/brcmstb_thermal.c | 386
> +++++++++++++++++++++++++++++
>  4 files changed, 395 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/thermal/broadcom/brcmstb_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index b5b5fac..396ad6b 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -408,7 +408,7 @@ config MTK_THERMAL
>     controller present in Mediatek SoCs
>
>  menu "Broadcom thermal drivers"
> -depends on ARCH_BCM || COMPILE_TEST
> +depends on ARCH_BCM || ARCH_BRCMSTB || COMPILE_TEST
>  source "drivers/thermal/broadcom/Kconfig"
>  endmenu
>
> diff --git a/drivers/thermal/broadcom/Kconfig
> b/drivers/thermal/broadcom/Kconfig
> index 42c098e..c106a15 100644
> --- a/drivers/thermal/broadcom/Kconfig
> +++ b/drivers/thermal/broadcom/Kconfig
> @@ -6,6 +6,13 @@ config BCM2835_THERMAL
>   help
>     Support for thermal sensors on Broadcom bcm2835 SoCs.
>
> +config BRCMSTB_THERMAL
> + tristate "Broadcom STB AVS TMON thermal driver"
> + depends on ARCH_BRCMSTB || COMPILE_TEST
> + help
> +   Enable this driver if you have a Broadcom STB SoC and
> would like
> +   thermal framework support.
> +

I don't understand why I got the following checkpatch warning

WARNING: please write a paragraph that describes the config symbol
fully
#73: FILE: drivers/thermal/broadcom/Kconfig:9:
+config BRCMSTB_THERMAL

I didn't see this for other Kconfig changes.

thanks,
rui

>  config BCM_NS_THERMAL
>   tristate "Northstar thermal driver"
>   depends on ARCH_BCM_IPROC || COMPILE_TEST
> diff --git a/drivers/thermal/broadcom/Makefile
> b/drivers/thermal/broadcom/Makefile
> index c6f62e4..fae10ec 100644
> --- a/drivers/thermal/broadcom/Makefile
> +++ b/drivers/thermal/broadcom/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_BCM2835_THERMAL) += bcm2835_thermal.o
> +obj-$(CONFIG_BRCMSTB_THERMAL) += brcmstb_thermal.o
>  obj-$(CONFIG_BCM_NS_THERMAL) += ns-thermal.o
> diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c
> b/drivers/thermal/broadcom/brcmstb_thermal.c
> new file mode 100644
> index 0000000..87b8e7a
> --- /dev/null
> +++ b/drivers/thermal/broadcom/brcmstb_thermal.c
> @@ -0,0 +1,386 @@
> +/*
> + * Broadcom STB AVS TMON thermal sensor driver
> + *
> + * Copyright (c) 2015-2017 Broadcom
> + *
> + * This software is licensed under the terms of the GNU General
> Public
> + * License version 2, as published by the Free Software Foundation,
> and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#define DRV_NAME "brcmstb_thermal"
> +
> +#define pr_fmt(fmt) DRV_NAME ": " fmt
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/irqreturn.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/thermal.h>
> +
> +#define AVS_TMON_STATUS 0x00
> + #define AVS_TMON_STATUS_valid_msk BIT(11)
> + #define AVS_TMON_STATUS_data_msk GENMASK(10, 1)
> + #define AVS_TMON_STATUS_data_shift 1
> +
> +#define AVS_TMON_EN_OVERTEMP_RESET 0x04
> + #define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0)
> +
> +#define AVS_TMON_RESET_THRESH 0x08
> + #define AVS_TMON_RESET_THRESH_msk GENMASK(10, 1)
> + #define AVS_TMON_RESET_THRESH_shift 1
> +
> +#define AVS_TMON_INT_IDLE_TIME 0x10
> +
> +#define AVS_TMON_EN_TEMP_INT_SRCS 0x14
> + #define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1)
> + #define AVS_TMON_EN_TEMP_INT_SRCS_low BIT(0)
> +
> +#define AVS_TMON_INT_THRESH 0x18
> + #define AVS_TMON_INT_THRESH_high_msk GENMASK(26, 17)
> + #define AVS_TMON_INT_THRESH_high_shift 17
> + #define AVS_TMON_INT_THRESH_low_msk GENMASK(10, 1)
> + #define AVS_TMON_INT_THRESH_low_shift 1
> +
> +#define AVS_TMON_TEMP_INT_CODE 0x1c
> +#define AVS_TMON_TP_TEST_ENABLE 0x20
> +
> +/* Default coefficients */
> +#define AVS_TMON_TEMP_SLOPE -487
> +#define AVS_TMON_TEMP_OFFSET 410040
> +
> +/* HW related temperature constants */
> +#define AVS_TMON_TEMP_MAX 0x3ff
> +#define AVS_TMON_TEMP_MIN -88161
> +#define AVS_TMON_TEMP_MASK AVS_TMON_TEMP_MAX
> +
> +enum avs_tmon_trip_type {
> + TMON_TRIP_TYPE_LOW = 0,
> + TMON_TRIP_TYPE_HIGH,
> + TMON_TRIP_TYPE_RESET,
> + TMON_TRIP_TYPE_MAX,
> +};
> +
> +struct avs_tmon_trip {
> + /* HW bit to enable the trip */
> + u32 enable_offs;
> + u32 enable_mask;
> +
> + /* HW field to read the trip temperature */
> + u32 reg_offs;
> + u32 reg_msk;
> + int reg_shift;
> +};
> +
> +static struct avs_tmon_trip avs_tmon_trips[] = {
> + /* Trips when temperature is below threshold */
> + [TMON_TRIP_TYPE_LOW] = {
> + .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
> + .enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_low,
> + .reg_offs = AVS_TMON_INT_THRESH,
> + .reg_msk = AVS_TMON_INT_THRESH_low_msk,
> + .reg_shift = AVS_TMON_INT_THRESH_low_shift,
> + },
> + /* Trips when temperature is above threshold */
> + [TMON_TRIP_TYPE_HIGH] = {
> + .enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
> + .enable_mask =
> AVS_TMON_EN_TEMP_INT_SRCS_high,
> + .reg_offs = AVS_TMON_INT_THRESH,
> + .reg_msk = AVS_TMON_INT_THRESH_high_msk,
> + .reg_shift = AVS_TMON_INT_THRESH_high_shift,
> + },
> + /* Automatically resets chip when above threshold */
> + [TMON_TRIP_TYPE_RESET] = {
> + .enable_offs = AVS_TMON_EN_OVERTEMP_RESET,
> + .enable_mask =
> AVS_TMON_EN_OVERTEMP_RESET_msk,
> + .reg_offs = AVS_TMON_RESET_THRESH,
> + .reg_msk = AVS_TMON_RESET_THRESH_msk,
> + .reg_shift = AVS_TMON_RESET_THRESH_shift,
> + },
> +};
> +
> +struct brcmstb_thermal_priv {
> + void __iomem *tmon_base;
> + struct device *dev;
> + struct thermal_zone_device *thermal;
> +};
> +
> +static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int
> *slope,
> + int *offset)
> +{
> + *slope = thermal_zone_get_slope(tz);
> + *offset = thermal_zone_get_offset(tz);
> +}
> +
> +/* Convert a HW code to a temperature reading (millidegree celsius)
> */
> +static inline int avs_tmon_code_to_temp(struct thermal_zone_device
> *tz,
> + u32 code)
> +{
> + const int val = code & AVS_TMON_TEMP_MASK;
> + int slope, offset;
> +
> + avs_tmon_get_coeffs(tz, &slope, &offset);
> +
> + return slope * val + offset;
> +}
> +
> +/*
> + * Convert a temperature value (millidegree celsius) to a HW code
> + *
> + * @temp: temperature to convert
> + * @low: if true, round toward the low side
> + */
> +static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device
> *tz,
> + int temp, bool low)
> +{
> + int slope, offset;
> +
> + if (temp < AVS_TMON_TEMP_MIN)
> + return AVS_TMON_TEMP_MAX; /* Maximum code value */
> +
> + avs_tmon_get_coeffs(tz, &slope, &offset);
> +
> + if (temp >= offset)
> + return 0; /* Minimum code value */
> +
> + if (low)
> + return (u32)(DIV_ROUND_UP(offset - temp,
> abs(slope)));
> + else
> + return (u32)((offset - temp) / abs(slope));
> +}
> +
> +static int brcmstb_get_temp(void *data, int *temp)
> +{
> + struct brcmstb_thermal_priv *priv = data;
> + u32 val;
> + long t;
> +
> + val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
> +
> + if (!(val & AVS_TMON_STATUS_valid_msk)) {
> + dev_err(priv->dev, "reading not valid\n");
> + return -EIO;
> + }
> +
> + val = (val & AVS_TMON_STATUS_data_msk) >>
> AVS_TMON_STATUS_data_shift;
> +
> + t = avs_tmon_code_to_temp(priv->thermal, val);
> + if (t < 0)
> + *temp = 0;
> + else
> + *temp = t;
> +
> + return 0;
> +}
> +
> +static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
> +  enum avs_tmon_trip_type type, int
> en)
> +{
> + struct avs_tmon_trip *trip = &avs_tmon_trips[type];
> + u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
> +
> + dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" :
> "dis", type);
> +
> + if (en)
> + val |= trip->enable_mask;
> + else
> + val &= ~trip->enable_mask;
> +
> + __raw_writel(val, priv->tmon_base + trip->enable_offs);
> +}
> +
> +static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
> +   enum avs_tmon_trip_type type)
> +{
> + struct avs_tmon_trip *trip = &avs_tmon_trips[type];
> + u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
> +
> + val &= trip->reg_msk;
> + val >>= trip->reg_shift;
> +
> + return avs_tmon_code_to_temp(priv->thermal, val);
> +}
> +
> +static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv
> *priv,
> +    enum avs_tmon_trip_type type,
> +    int temp)
> +{
> + struct avs_tmon_trip *trip = &avs_tmon_trips[type];
> + u32 val, orig;
> +
> + dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
> +
> + /* round toward low temp for the low interrupt */
> + val = avs_tmon_temp_to_code(priv->thermal, temp,
> +     type == TMON_TRIP_TYPE_LOW);
> +
> + val <<= trip->reg_shift;
> + val &= trip->reg_msk;
> +
> + orig = __raw_readl(priv->tmon_base + trip->reg_offs);
> + orig &= ~trip->reg_msk;
> + orig |= val;
> + __raw_writel(orig, priv->tmon_base + trip->reg_offs);
> +}
> +
> +static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
> +{
> + u32 val;
> +
> + val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
> + return avs_tmon_code_to_temp(priv->thermal, val);
> +}
> +
> +static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
> +{
> + struct brcmstb_thermal_priv *priv = data;
> + int low, high, intr;
> +
> + low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
> + high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
> + intr = avs_tmon_get_intr_temp(priv);
> +
> + dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
> + low, intr, high);
> +
> + /* Disable high-temp until next threshold shift */
> + if (intr >= high)
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
> + /* Disable low-temp until next threshold shift */
> + if (intr <= low)
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
> +
> + /*
> +  * Notify using the interrupt temperature, in case the
> temperature
> +  * changes before it can next be read out
> +  */
> + thermal_zone_device_update(priv->thermal, intr);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int brcmstb_set_trips(void *data, int low, int high)
> +{
> + struct brcmstb_thermal_priv *priv = data;
> +
> + dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
> +
> + if (low) {
> + if (low > INT_MAX)
> + low = INT_MAX;
> + avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW,
> low);
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
> + } else {
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
> + }
> +
> + if (high < ULONG_MAX) {
> + if (high > INT_MAX)
> + high = INT_MAX;
> + avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH,
> high);
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
> + } else {
> + avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
> + }
> +
> + return 0;
> +}
> +
> +static struct thermal_zone_of_device_ops of_ops = {
> + .get_temp = brcmstb_get_temp,
> + .set_trips = brcmstb_set_trips,
> +};
> +
> +static const struct of_device_id brcmstb_thermal_id_table[] = {
> + { .compatible = "brcm,avs-tmon" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
> +
> +static int brcmstb_thermal_probe(struct platform_device *pdev)
> +{
> + struct thermal_zone_device *thermal;
> + struct brcmstb_thermal_priv *priv;
> + struct resource *res;
> + int irq, ret;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->tmon_base))
> + return PTR_ERR(priv->tmon_base);
> +
> + priv->dev = &pdev->dev;
> + platform_set_drvdata(pdev, priv);
> +
> + thermal = thermal_zone_of_sensor_register(&pdev->dev, 0,
> priv, &of_ops);
> + if (IS_ERR(thermal)) {
> + ret = PTR_ERR(thermal);
> + dev_err(&pdev->dev, "could not register sensor:
> %d\n", ret);
> + return ret;
> + }
> +
> + priv->thermal = thermal;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "could not get IRQ\n");
> + ret = irq;
> + goto err;
> + }
> + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> + brcmstb_tmon_irq_thread,
> IRQF_ONESHOT,
> + DRV_NAME, priv);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "could not request IRQ: %d\n",
> ret);
> + goto err;
> + }
> +
> + dev_info(&pdev->dev, "registered AVS TMON of-sensor
> driver\n");
> +
> + return 0;
> +
> +err:
> + thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
> + return ret;
> +}
> +
> +static int brcmstb_thermal_exit(struct platform_device *pdev)
> +{
> + struct brcmstb_thermal_priv *priv =
> platform_get_drvdata(pdev);
> + struct thermal_zone_device *thermal = priv->thermal;
> +
> + if (thermal)
> + thermal_zone_of_sensor_unregister(&pdev->dev, priv-
> >thermal);
> +
> + return 0;
> +}
> +
> +static struct platform_driver brcmstb_thermal_driver = {
> + .probe = brcmstb_thermal_probe,
> + .remove = brcmstb_thermal_exit,
> + .driver = {
> + .name = DRV_NAME,
> + .of_match_table = brcmstb_thermal_id_table,
> + },
> +};
> +module_platform_driver(brcmstb_thermal_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Brian Norris");
> +MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");