Re: [PATCH V7 2/4] thermal: imx_sc: add i.MX system controller thermal support

From: Eduardo Valentin
Date: Wed Feb 20 2019 - 20:08:14 EST


On Wed, Feb 20, 2019 at 06:53:40AM +0000, Anson Huang wrote:
> i.MX8QXP is an ARMv8 SoC which has a Cortex-M4 system controller
> inside, the system controller is in charge of controlling power,
> clock and thermal sensors etc..
>
> This patch adds i.MX system controller thermal driver support,
> Linux kernel has to communicate with system controller via MU
> (message unit) IPC to get each thermal sensor's temperature,
> it supports multiple sensors which are passed from device tree,
> please see the binding doc for details.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> Changes since V6:
> - use "fsl,imx-sc-thermal" compatible to make SC thermal driver more generic for other i.MX8 SoCs
> with system controller inside.
> ---
> drivers/thermal/Kconfig | 11 +++
> drivers/thermal/Makefile | 1 +
> drivers/thermal/imx_sc_thermal.c | 161 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 173 insertions(+)
> create mode 100644 drivers/thermal/imx_sc_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 58bb7d7..fec0ef5 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -223,6 +223,17 @@ config IMX_THERMAL
> cpufreq is used as the cooling device to throttle CPUs when the
> passive trip is crossed.
>
> +config IMX_SC_THERMAL
> + tristate "Temperature sensor driver for NXP i.MX SoCs with System Controller"
> + depends on (ARCH_MXC && IMX_SCU) || COMPILE_TEST
> + depends on OF
> + help
> + Support for Temperature Monitor (TEMPMON) found on NXP i.MX SoCs with
> + system controller inside, Linux kernel has to communicate with system
> + controller via MU (message unit) IPC to get temperature from thermal
> + sensor. It supports one critical trip point and one
> + passive trip point for each thermal sensor.
> +
> config MAX77620_THERMAL
> tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
> depends on MFD_MAX77620
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 486d682..4062627 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -40,6 +40,7 @@ obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o
> obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
> obj-$(CONFIG_TANGO_THERMAL) += tango_thermal.o
> obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
> +obj-$(CONFIG_IMX_SC_THERMAL) += imx_sc_thermal.o
> obj-$(CONFIG_MAX77620_THERMAL) += max77620_thermal.o
> obj-$(CONFIG_QORIQ_THERMAL) += qoriq_thermal.o
> obj-$(CONFIG_DA9062_THERMAL) += da9062-thermal.o
> diff --git a/drivers/thermal/imx_sc_thermal.c b/drivers/thermal/imx_sc_thermal.c
> new file mode 100644
> index 0000000..1a8b978
> --- /dev/null
> +++ b/drivers/thermal/imx_sc_thermal.c
> @@ -0,0 +1,161 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2018-2019 NXP.
> + */
> +
> +#include <linux/err.h>
> +#include <linux/firmware/imx/sci.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/thermal.h>
> +
> +#include "thermal_core.h"
> +
> +#define IMX_SC_MISC_FUNC_GET_TEMP 13
> +#define IMX_SC_C_TEMP 0
> +
> +static struct imx_sc_ipc *thermal_ipc_handle;
> +
> +struct imx_sc_sensor {
> + struct thermal_zone_device *tzd;
> + u32 resource_id;
> +};
> +
> +struct imx_sc_thermal_data {
> + struct imx_sc_sensor *sensor;
> +};
> +
> +struct req_get_temp {
> + u16 resource_id;
> + u8 type;
> +} __packed;
> +
> +struct resp_get_temp {
> + u16 celsius;
> + u8 tenths;
> +} __packed;
> +
> +struct imx_sc_msg_misc_get_temp {
> + struct imx_sc_rpc_msg hdr;
> + union {
> + struct req_get_temp req;
> + struct resp_get_temp resp;
> + } data;
> +} __packed;
> +
> +static int imx_sc_thermal_get_temp(void *data, int *temp)
> +{
> + struct imx_sc_msg_misc_get_temp msg;
> + struct imx_sc_rpc_msg *hdr = &msg.hdr;
> + struct imx_sc_sensor *sensor = data;
> + int ret;
> +
> + msg.data.req.resource_id = sensor->resource_id;
> + msg.data.req.type = IMX_SC_C_TEMP;
> +
> + hdr->ver = IMX_SC_RPC_VERSION;
> + hdr->svc = IMX_SC_RPC_SVC_MISC;
> + hdr->func = IMX_SC_MISC_FUNC_GET_TEMP;
> + hdr->size = 2;
> +
> + ret = imx_scu_call_rpc(thermal_ipc_handle, &msg, true);
> + if (ret) {
> + pr_err("read temp sensor %d failed, ret %d\n",
> + sensor->resource_id, ret);
> + return ret;
> + }
> +
> + *temp = msg.data.resp.celsius * 1000 + msg.data.resp.tenths * 100;
> +
> + return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops imx_sc_thermal_ops = {
> + .get_temp = imx_sc_thermal_get_temp,
> +};
> +
> +static int imx_sc_thermal_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device_node *sensor_np = NULL;
> + struct imx_sc_thermal_data *data;
> + struct imx_sc_sensor *sensors;
> + u32 sensor_num;
> + int ret, i;
> +
> + ret = imx_scu_get_handle(&thermal_ipc_handle);
> + if (ret)
> + return ret;
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + ret = of_property_read_u32(np, "tsens-num", &sensor_num);
> + if (ret || !sensor_num) {
> + dev_err(&pdev->dev, "failed to get valid temp sensor number!\n");
> + return -EINVAL;
> + }
> +
> + sensors = devm_kzalloc(&pdev->dev, sizeof(*data->sensor) * sensor_num,
> + GFP_KERNEL);
> + if (!sensors)
> + return -ENOMEM;
> +
> + data->sensor = sensors;
> +
> + np = of_find_node_by_name(NULL, "thermal-zones");
> + if (!np)
> + return -ENODEV;
> +
> + for (i = 0; i < sensor_num; i++) {
> + struct imx_sc_sensor *sensor = &data->sensor[i];
> +
> + sensor_np = of_get_next_child(np, sensor_np);
> + ret = of_property_read_u32(sensor_np, "imx,sensor-resource-id",

I think the idea here is to have imx,sensor-resource-id part of the
tsens node, not part of the thermal-zone node.

> + &sensor->resource_id);
> + if (ret) {
> + dev_err(&pdev->dev,
> + "failed to get valid sensor resource id: %d\n",
> + ret);
> + break;
> + }
> +
> + sensor->tzd = devm_thermal_zone_of_sensor_register(&pdev->dev,
> + i,
> + sensor,
> + &imx_sc_thermal_ops);
> + if (IS_ERR(sensor->tzd)) {
> + dev_err(&pdev->dev, "failed to register thermal zone\n");
> + ret = PTR_ERR(sensor->tzd);
> + break;
> + }
> + }
> +
> + of_node_put(np);
> + of_node_put(sensor_np);
> +
> + return ret;
> +}
> +
> +static const struct of_device_id imx_sc_thermal_table[] = {
> + { .compatible = "fsl,imx-sc-thermal", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, imx_sc_thermal_table);
> +
> +static struct platform_driver imx_sc_thermal_driver = {
> + .probe = imx_sc_thermal_probe,
> + .driver = {
> + .name = "imx-sc-thermal",
> + .of_match_table = imx_sc_thermal_table,
> + },
> +};
> +module_platform_driver(imx_sc_thermal_driver);
> +
> +MODULE_AUTHOR("Anson Huang <Anson.Huang@xxxxxxx>");
> +MODULE_DESCRIPTION("Thermal driver for NXP i.MX SoCs with system controller");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>