Re: [PATCH 1/3] thermal: bcm281xx: Add Temperature Monitor driver

[Grant Likely]

On Fri, 25 Oct 2013 17:00:27 -0700, "Wendy Ng" <wendy.ng@xxxxxxxxxxxx> wrote:
> This adds the support for Temperature Monitor (TMON) driver for
> Broadcom bcm281xx SoCs. This driver plugs into the Thermal Framework.
> 
> Note that this version of the TMON driver does support interrupt-driven
> mode -- only polling-mode of the thermal framework can be used.
> 
> Signed-off-by: Wendy Ng <wendy.ng@xxxxxxxxxxxx>
> Reviewed-by: Markus Mayer <mmayer@xxxxxxxxxxxx>
> Reviewed-by: Christian Daudt <csd@xxxxxxxxxxxx>
> Reviewed-by: Matt Porter <matt.porter@xxxxxxxxxx>
> Reviewed-by: Tim Kryger <tim.kryger@xxxxxxxxxx>
> ---
>  .../bindings/thermal/bcm-kona-thermal.txt          |   24 +++
>  drivers/thermal/Kconfig                            |   11 ++
>  drivers/thermal/Makefile                           |    1 +
>  drivers/thermal/bcm_kona_tmon.c                    |  173 ++++++++++++++++++++
>  4 files changed, 209 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/bcm-kona-thermal.txt
>  create mode 100644 drivers/thermal/bcm_kona_tmon.c
> 
> diff --git a/Documentation/devicetree/bindings/thermal/bcm-kona-thermal.txt b/Documentation/devicetree/bindings/thermal/bcm-kona-thermal.txt
> new file mode 100644
> index 0000000..225b898
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/bcm-kona-thermal.txt
> @@ -0,0 +1,24 @@
> +* Broadcom Kona TMON bindings
> +
> +This version is for the Kona family of SoCs.  The TMON (Temperature Monitor)
> +block in a Kona SoC device is used to measure the chip temperature at constant
> +intervals.
> +The TMON block asserts an interrupt if temperature exceeds a user programmed
> +threshold value.  The TMON block would reset the entire device once it
> +reaches a critical temperature which is also a programmable setting.
> +
> +Required properties:
> +- compatible : "brcm,bcm11351-tmon", "brcm,kona-tmon"
> +- reg : Address range of the thermal register
> +- clocks : the clock signal that drives the TMON block
> +- interrupts: the interrupt signal associated with the TMON block
> +
> +
> +Example:
> +	tmon@34008000 {
> +		compatible = "brcm,bcm11351-tmon", "brcm,kona-tmon";
> +		reg = <0x34008000 0x0024>;
> +		clocks = <&tmon_1m_clk>;
> +		interrupts = <GIC_SPI 183 IRQ_TYPE_LEVEL_HIGH>;
> +		status = "disabled";

I would drop the status="disabled" from the example, but otherwise the
binding looks fine.

g.

> +	};
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 9e7cc3f..02200ad 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -166,6 +166,17 @@ config DB8500_THERMAL
>  	  created. Cooling devices can be bound to the trip points to cool this
>  	  thermal zone if trip points reached.
>  
> +config BCM_KONA_TMON_THERMAL
> +	tristate "Temperature Monitor driver on Broadcom Kona family of SoCs"
> +	depends on ARCH_BCM_MOBILE
> +	depends on THERMAL_OF
> +	default y
> +	help
> +	  If you say yes here you get support for the TMON
> +	  (Temperature Monitor) in Broadcom Kona family of SoCs.
> +	  This also provides the generic support of the Thermal Framework
> +	  for Broadcom Kona family of SoCs.
> +
>  config ARMADA_THERMAL
>  	tristate "Armada 370/XP thermal management"
>  	depends on ARCH_MVEBU
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 4b03956..5e85354 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -22,6 +22,7 @@ obj-$(CONFIG_SPEAR_THERMAL)	+= spear_thermal.o
>  obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
>  obj-$(CONFIG_KIRKWOOD_THERMAL)  += kirkwood_thermal.o
>  obj-y				+= samsung/
> +obj-$(CONFIG_BCM_KONA_TMON_THERMAL)	+= bcm_kona_tmon.o
>  obj-$(CONFIG_DOVE_THERMAL)  	+= dove_thermal.o
>  obj-$(CONFIG_DB8500_THERMAL)	+= db8500_thermal.o
>  obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
> diff --git a/drivers/thermal/bcm_kona_tmon.c b/drivers/thermal/bcm_kona_tmon.c
> new file mode 100644
> index 0000000..69ae0b2
> --- /dev/null
> +++ b/drivers/thermal/bcm_kona_tmon.c
> @@ -0,0 +1,173 @@
> +/*
> + * Copyright 2013 Broadcom Corporation.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2,
> + * as published by the Free Software Foundation (the "GPL").
> + *
> + * 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.
> + *
> + * A copy of the GPL is available at http://www.broadcom.com/licenses/GPLv2.php,
> + * or by writing to the Free Software Foundation, Inc.,
> + * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
> + */
> +
> +/**
> +*  Broadcom Kona Temperature Monitor (TMON) driver
> +*
> +*  Note: The TMON hardware monitors a single sensor.
> +*/
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/thermal.h>
> +
> +
> +/* From TMON Register Database */
> +#define TMON_TEMP_VAL_OFFSET			0x0000001c
> +#define TMON_TEMP_VAL_TEMP_VAL_SHIFT		0
> +#define TMON_TEMP_VAL_TEMP_VAL_MASK		0x000003ff
> +
> +/* Broadcom TMON Private Data Structure */
> +struct bcm_tmon_data_priv {
> +	void __iomem *base;
> +	struct clk *external_clk;
> +	struct thermal_zone_device *therm_dev;
> +};
> +
> +/* Temperature conversion function for TMON block */
> +static long raw_to_mcelsius(u32 raw)
> +{
> +	/*
> +	 * According to Broadcom internal Analog Module Specification
> +	 * the formula for converting TMON block output to temperature in
> +	 * degree Celsius is:
> +	 *	T = 428 - (0.561 * raw)
> +	 * Note: the valid operating range for the TMON block is -40C to 125C
> +	 */
> +	return 428000 - (561 * (long)raw);
> +}
> +
> +/* Get temperature callback function for thermal zone */
> +static int bcm_get_temp(void *sensor_data, long *temp)
> +{
> +	u32 raw;
> +	long mcelsius;
> +	struct bcm_tmon_data_priv *priv = sensor_data;
> +
> +	if (!priv) {
> +		pr_err("%s: input sensor_data not initialized.\n", __func__);
> +		return -EINVAL;
> +	}
> +
> +	raw = (readl(priv->base + TMON_TEMP_VAL_OFFSET)
> +		& TMON_TEMP_VAL_TEMP_VAL_MASK) >> TMON_TEMP_VAL_TEMP_VAL_SHIFT;
> +
> +	pr_debug("%s: raw temp 0x%x\n", __func__, raw);
> +
> +	mcelsius = raw_to_mcelsius(raw);
> +
> +	/*
> +	 * Since 'mcelsius' might be negative, we need to limit it to smallest
> +	 * unsigned value before returning it to thermal framework.
> +	 */
> +	if (mcelsius < 0)
> +		*temp = 0;
> +	else
> +		*temp = mcelsius;
> +
> +	pr_debug("%s: final temp %d\n", __func__, (int) *temp);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id bcm_kona_tmon_match_table[] = {
> +	{ .compatible = "brcm,kona-tmon" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, bcm_kona_tmon_match_table);
> +
> +static int bcm_kona_tmon_probe(struct platform_device *pdev)
> +{
> +	struct thermal_zone_device *thermal = NULL;
> +	struct bcm_tmon_data_priv *priv;
> +	struct resource *res;
> +
> +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv) {
> +		dev_err(&pdev->dev, "Failed to malloc priv.\n");
> +		return -ENOMEM;
> +	}
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	priv->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(priv->base))
> +		return PTR_ERR(priv->base);
> +
> +	priv->external_clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(priv->external_clk))
> +		return -ENODEV;
> +
> +	if (clk_prepare_enable(priv->external_clk) != 0)
> +		return -EINVAL;
> +
> +	/*
> +	 * Note that get_trend() function is NULL.  This is OK for now as
> +	 * we can rely on the get_tz_trend() from the Thermal Framework until
> +	 * we come up with a better way to determine the trend.
> +	 */
> +	thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv,
> +						bcm_get_temp, NULL);
> +
> +	if (IS_ERR(thermal)) {
> +		dev_err(&pdev->dev, "Failed to register BCM Kona TMON.\n");
> +		clk_disable_unprepare(priv->external_clk);
> +		return PTR_ERR(thermal);
> +	}
> +
> +	priv->therm_dev = thermal;
> +
> +	platform_set_drvdata(pdev, priv);
> +
> +	dev_info(&pdev->dev, "BCM Kona TMON Initialized.\n");
> +
> +	return 0;
> +}
> +
> +static int bcm_kona_tmon_remove(struct platform_device *pdev)
> +{
> +	struct bcm_tmon_data_priv *priv = platform_get_drvdata(pdev);
> +
> +	thermal_zone_of_sensor_unregister(&pdev->dev, priv->therm_dev);
> +
> +	clk_disable_unprepare(priv->external_clk);
> +
> +	dev_info(&pdev->dev, "BCM Kona TMON Uninitialized.\n");
> +
> +	return 0;
> +}
> +
> +static struct platform_driver bcm_kona_tmon_driver = {
> +	.driver = {
> +		.name = "bcm-kona-tmon",
> +		.owner = THIS_MODULE,
> +		.of_match_table = bcm_kona_tmon_match_table,
> +	},
> +	.probe = bcm_kona_tmon_probe,
> +	.remove = bcm_kona_tmon_remove,
> +};
> +
> +module_platform_driver(bcm_kona_tmon_driver);
> +
> +MODULE_DESCRIPTION("Broadcom Kona Temperature Monitor Driver");
> +MODULE_AUTHOR("Broadcom Corporation");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:bcm-kona-tmon");
> -- 
> 1.7.9.5
> 
> 
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