[PATCH 1/4] thermal: Add driver for Armada 370/XP SoC thermal management
R, Durgadoss
durgadoss.r at intel.com
Mon Mar 25 13:27:24 EDT 2013
> -----Original Message-----
> From: linux-pm-owner at vger.kernel.org [mailto:linux-pm-
> owner at vger.kernel.org] On Behalf Of Ezequiel Garcia
> Sent: Monday, March 25, 2013 8:57 PM
> To: linux-arm-kernel at lists.infradead.org; linux-pm at vger.kernel.org
> Cc: Lior Amsalem; Nobuhiro Iwamatsu; Zhang, Rui; Sebastian Hesselbarth;
> Andrew Lunn; Thomas Petazzoni; Gregory Clement; Jason Cooper; Ezequiel
> Garcia
> Subject: [PATCH 1/4] thermal: Add driver for Armada 370/XP SoC thermal
> management
>
> This driver supports both Armada 370 and Armada XP SoC
> thermal management controllers.
>
> Armada 370 has a register to check a valid temperature, whereas
> Armada XP does not. Each has a different initialization (i.e. calibration)
> function. The temperature conversion formula is the same for both.
>
> The controller present in each SoC have a very similar feature set,
> so it corresponds to have one driver to support both of them.
>
> Although this driver may present similarities to Dove and Kirkwood
> thermal driver, the exact differences and coincidences are not fully
> known. For this reason, support is given through a separate driver.
Nice commit message, that has all the details :-)
>
> Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
> ---
> .../devicetree/bindings/thermal/armada-thermal.txt | 22 ++
> drivers/thermal/Kconfig | 8 +
> drivers/thermal/Makefile | 1 +
> drivers/thermal/armada_thermal.c | 236
> ++++++++++++++++++++
> 4 files changed, 267 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/devicetree/bindings/thermal/armada-
> thermal.txt
> create mode 100644 drivers/thermal/armada_thermal.c
>
> diff --git a/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> b/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> new file mode 100644
> index 0000000..fff93d5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/armada-thermal.txt
> @@ -0,0 +1,22 @@
> +* Marvell Armada 370/XP thermal management
> +
> +Required properties:
> +
> +- compatible: Should be set to one of the following:
> + marvell,armada370-thermal
> + marvell,armadaxp-thermal
> +
> +- reg: Device's register space.
> + Two entries are expected, see the examples below.
> + The first one is required for the sensor register;
> + the second one is required for the control register
> + to be used for sensor initialization (a.k.a. calibration).
> +
> +Example:
> +
> + thermal at d0018300 {
> + compatible = "marvell,armada370-thermal";
> + reg = <0xd0018300 0x4
> + 0xd0018304 0x4>;
> + status = "okay";
> + };
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index a764f16..fcd5a27 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -134,6 +134,14 @@ config DOVE_THERMAL
> Support for the Dove thermal sensor driver in the Linux thermal
> framework.
>
> +config ARMADA_THERMAL
> + tristate "Armada 370/XP thermal management"
> + depends on ARCH_MVEBU
> + depends on OF
> + help
> + Enable this option if you want to have support for thermal
> management
> + controller present in Armada 370 and Armada XP SoC.
> +
> config DB8500_THERMAL
> bool "DB8500 thermal management"
> depends on ARCH_U8500
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index d3a2b38..4209054 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_THERMAL_GOV_USER_SPACE) +=
> user_space.o
> obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o
>
> # platform thermal drivers
> +obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
> obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o
> obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o
> obj-$(CONFIG_KIRKWOOD_THERMAL) += kirkwood_thermal.o
> diff --git a/drivers/thermal/armada_thermal.c
> b/drivers/thermal/armada_thermal.c
> new file mode 100644
> index 0000000..dc83a86
> --- /dev/null
> +++ b/drivers/thermal/armada_thermal.c
> @@ -0,0 +1,236 @@
> +/*
> + * Marvell Armada 370/XP thermal sensor driver
> + *
> + * Copyright (C) 2013 Marvell
> + *
> + * 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.
> + *
> + */
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/platform_device.h>
> +#include <linux/of_device.h>
> +#include <linux/thermal.h>
> +
> +#define THERMAL_VALID_OFFSET 9
> +#define THERMAL_VALID_MASK 0x1
> +#define THERMAL_TEMP_OFFSET 10
> +#define THERMAL_TEMP_MASK 0x1ff
> +
> +/* Thermal Manager Control and Status Register */
> +#define PMU_TDC0_SW_RST_MASK (0x1 << 1)
> +#define PMU_TM_DISABLE_OFFS 0
> +#define PMU_TM_DISABLE_MASK (0x1 <<
> PMU_TM_DISABLE_OFFS)
> +#define PMU_TDC0_REF_CAL_CNT_OFFS 11
> +#define PMU_TDC0_REF_CAL_CNT_MASK (0x1ff <<
> PMU_TDC0_REF_CAL_CNT_OFFS)
> +#define PMU_TDC0_OTF_CAL_MASK (0x1 << 30)
> +#define PMU_TDC0_START_CAL_MASK (0x1 << 25)
> +
> +struct armada_thermal_ops;
> +
> +/* Marvell EBU Thermal Sensor Dev Structure */
> +struct armada_thermal_priv {
> + void __iomem *sensor;
> + void __iomem *control;
> + struct armada_thermal_ops *ops;
> +};
> +
> +struct armada_thermal_ops {
> + /* Initialize the sensor */
> + void (*init_sensor)(struct armada_thermal_priv *);
> +
> + /* Test for a valid sensor value (optional) */
> + bool (*is_valid)(struct armada_thermal_priv *);
> +};
> +
> +static void armadaxp_init_sensor(struct armada_thermal_priv *priv)
> +{
> + unsigned long reg;
> +
> + /* ??? */
> + reg = readl_relaxed(priv->control);
> + reg |= PMU_TDC0_OTF_CAL_MASK;
> + writel(reg, priv->control);
> +
> + /* Reference calibration value */
> + reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
> + reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
> + writel(reg, priv->control);
I see these two blocks of code being the same for the below
function as well. Any specific reason for not making this block
as a common function and calling it from both the
_init_sensor functions ?
> +
> + /* Reset the sensor */
> + reg = readl_relaxed(priv->control);
> + writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
> +
> + writel(reg, priv->control);
> +
> + /* Enable the sensor */
> + reg = readl_relaxed(priv->sensor);
> + reg &= ~PMU_TM_DISABLE_MASK;
> + writel(reg, priv->sensor);
> +}
> +
> +static void armada370_init_sensor(struct armada_thermal_priv *priv)
> +{
> + unsigned long reg;
> +
> + /* ??? */
> + reg = readl_relaxed(priv->control);
> + reg |= PMU_TDC0_OTF_CAL_MASK;
> + writel(reg, priv->control);
> +
> + /* Reference calibration value */
> + reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
> + reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
> + writel(reg, priv->control);
> +
> + /* ??? */
> + reg &= ~PMU_TDC0_START_CAL_MASK;
> + writel(reg, priv->control);
> +
> + /* FIXME: Why do we need this delay? */
> + mdelay(10);
> +}
> +
> +static bool armada_is_valid(struct armada_thermal_priv *priv)
> +{
> + unsigned long reg = readl_relaxed(priv->sensor);
> +
> + return (reg >> THERMAL_VALID_OFFSET) & THERMAL_VALID_MASK;
> +}
> +
> +static int armada_get_temp(struct thermal_zone_device *thermal,
> + unsigned long *temp)
> +{
> + struct armada_thermal_priv *priv = thermal->devdata;
> + unsigned long reg;
> +
> + /* Valid check */
> + if (priv->ops->is_valid && !priv->ops->is_valid(priv)) {
> + dev_err(&thermal->device,
> + "Temperature sensor reading not valid\n");
> + return -EIO;
> + }
> +
> + reg = (readl_relaxed(priv->sensor) >> THERMAL_TEMP_OFFSET) &
Can we have the readl_relaxed call as a separate statement ?
> + THERMAL_TEMP_MASK;
> + *temp = (3153000000UL - (10000000UL*reg)) / 13825;
If I substitute 1 for 'reg' I get 227341.7721...
Does this mean the temperature is 227 C ??
If you have the info, can you add a comment on what is the
valid range that 'reg' can take ?
Also, Is the resulting temperature
in MillidegreeCelsius ? If so, please add a comment saying so.
Thanks,
Durga
> + return 0;
> +}
> +
> +static struct thermal_zone_device_ops ops = {
> + .get_temp = armada_get_temp,
> +};
> +
> +static const struct armada_thermal_ops armadaxp_ops = {
> + .init_sensor = armadaxp_init_sensor,
> +};
> +
> +static const struct armada_thermal_ops armada370_ops = {
> + .is_valid = armada_is_valid,
> + .init_sensor = armada370_init_sensor,
> +};
> +
> +static const struct of_device_id armada_thermal_id_table[] = {
> + {
> + .compatible = "marvell,armadaxp-thermal",
> + .data = &armadaxp_ops,
> + },
> + {
> + .compatible = "marvell,armada370-thermal",
> + .data = &armada370_ops,
> + },
> + {
> + /* sentinel */
> + },
> +};
> +MODULE_DEVICE_TABLE(of, armada_thermal_id_table);
> +
> +static int armada_thermal_probe(struct platform_device *pdev)
> +{
> + struct thermal_zone_device *thermal;
> + const struct of_device_id *match;
> + struct armada_thermal_priv *priv;
> + struct resource *res;
> +
> + match = of_match_device(armada_thermal_id_table, &pdev->dev);
> + if (!match)
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(&pdev->dev, "Failed to get platform resource\n");
> + return -ENODEV;
> + }
> +
> + priv->sensor = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->sensor))
> + return PTR_ERR(priv->sensor);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> + if (!res) {
> + dev_err(&pdev->dev, "Failed to get platform resource\n");
> + return -ENODEV;
> + }
> +
> + priv->control = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->control))
> + return PTR_ERR(priv->control);
> +
> + priv->ops = (struct armada_thermal_ops *)match->data;
> + priv->ops->init_sensor(priv);
> +
> + thermal = thermal_zone_device_register("armada_thermal", 0, 0,
> + priv, &ops, NULL, 0, 0);
> + if (IS_ERR(thermal)) {
> + dev_err(&pdev->dev,
> + "Failed to register thermal zone device\n");
> + return PTR_ERR(thermal);
> + }
> +
> + platform_set_drvdata(pdev, thermal);
> +
> + return 0;
> +}
> +
> +static int armada_thermal_exit(struct platform_device *pdev)
> +{
> + struct thermal_zone_device *armada_thermal =
> + platform_get_drvdata(pdev);
> +
> + thermal_zone_device_unregister(armada_thermal);
> + platform_set_drvdata(pdev, NULL);
> +
> + return 0;
> +}
> +
> +static struct platform_driver armada_thermal_driver = {
> + .probe = armada_thermal_probe,
> + .remove = armada_thermal_exit,
> + .driver = {
> + .name = "armada_thermal",
> + .owner = THIS_MODULE,
> + .of_match_table =
> of_match_ptr(armada_thermal_id_table),
> + },
> +};
> +
> +module_platform_driver(armada_thermal_driver);
> +
> +MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia at free-
> electrons.com>");
> +MODULE_DESCRIPTION("Armada 370/XP thermal driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.7.8.6
>
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