Re: [PATCH v2 3/5] thermal: Add a driver for the Allwinner THS sensor

Maxime Ripard
2015-11-24T08:43:48Z

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On Mon, Nov 23, 2015 at 09:02:50AM +0100, Josef Gajdusek wrote:
> This patch adds support for the Sunxi thermal sensor on the Allwinner H3.

You can drop the sunxi here.

> Should be easily extendable for the A33/A83T/... as they have similar but
> not completely identical sensors.
>
> Signed-off-by: Josef Gajdusek <atx@atx.name>
> ---
> drivers/thermal/Kconfig | 7 +
> drivers/thermal/Makefile | 1 +
> drivers/thermal/sun8i_ths.c | 365 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 373 insertions(+)
> create mode 100644 drivers/thermal/sun8i_ths.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index c463c89..2b41147 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -365,6 +365,13 @@ config INTEL_PCH_THERMAL
> Thermal reporting device will provide temperature reading,
> programmable trip points and other information.
>
> +config SUN8I_THS
> + tristate "sun8i THS driver"
> + depends on MACH_SUN8I
> + depends on OF
> + help
> + Enable this to support thermal reporting on some newer Allwinner SoCs.
> +
> menu "Texas Instruments thermal drivers"
> depends on ARCH_HAS_BANDGAP || COMPILE_TEST
> source "drivers/thermal/ti-soc-thermal/Kconfig"
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index cfae6a6..227e1a1 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -48,3 +48,4 @@ obj-$(CONFIG_INTEL_PCH_THERMAL) += intel_pch_thermal.o
> obj-$(CONFIG_ST_THERMAL) += st/
> obj-$(CONFIG_TEGRA_SOCTHERM) += tegra_soctherm.o
> obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
> +obj-$(CONFIG_SUN8I_THS) += sun8i_ths.o
> diff --git a/drivers/thermal/sun8i_ths.c b/drivers/thermal/sun8i_ths.c
> new file mode 100644
> index 0000000..2c976ac
> --- /dev/null
> +++ b/drivers/thermal/sun8i_ths.c
> @@ -0,0 +1,365 @@
> +/*
> + * Sunxi THS driver

sun8i Thermal Sensor Driver

> + * Copyright (C) 2015 Josef Gajdusek
> + *
> + * 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/clk.h>
> +#include <linux/delay.h>

Are you using this header?

> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>

You probably don't need this one too.

> +#include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/printk.h>
> +#include <linux/reset.h>
> +#include <linux/slab.h>
> +#include <linux/thermal.h>
> +
> +#define THS_H3_CTRL0 0x00
> +#define THS_H3_CTRL1 0x04
> +#define THS_H3_CDAT 0x14
> +#define THS_H3_CTRL2 0x40
> +#define THS_H3_INT_CTRL 0x44
> +#define THS_H3_STAT 0x48
> +#define THS_H3_ALARM_CTRL 0x50
> +#define THS_H3_SHUTDOWN_CTRL 0x60
> +#define THS_H3_FILTER 0x70
> +#define THS_H3_CDATA 0x74
> +#define THS_H3_DATA 0x80
> +
> +#define THS_H3_CTRL0_SENSOR_ACQ0_OFFS 0
> +#define THS_H3_CTRL0_SENSOR_ACQ0(x) \
> + ((x) << THS_H3_CTRL0_SENSOR_ACQ0_OFFS)
> +#define THS_H3_CTRL1_ADC_CALI_EN_OFFS 17
> +#define THS_H3_CTRL1_ADC_CALI_EN \
> + BIT(THS_H3_CTRL1_ADC_CALI_EN_OFFS)
> +#define THS_H3_CTRL1_OP_BIAS_OFFS 20
> +#define THS_H3_CTRL1_OP_BIAS(x) \
> + ((x) << THS_H3_CTRL1_OP_BIAS_OFFS)
> +#define THS_H3_CTRL2_SENSE_EN_OFFS 0
> +#define THS_H3_CTRL2_SENSE_EN \
> + BIT(THS_H3_CTRL2_SENSE_EN_OFFS)
> +#define THS_H3_CTRL2_SENSOR_ACQ1_OFFS 16
> +#define THS_H3_CTRL2_SENSOR_ACQ1(x) \
> + ((x) << THS_H3_CTRL2_SENSOR_ACQ1_OFFS)
> +
> +#define THS_H3_INT_CTRL_ALARM_INT_EN_OFFS 0
> +#define THS_H3_INT_CTRL_ALARM_INT_EN \
> + BIT(THS_H3_INT_CTRL_ALARM_INT_EN_OFFS)
> +#define THS_H3_INT_CTRL_SHUT_INT_EN_OFFS 4
> +#define THS_H3_INT_CTRL_SHUT_INT_EN \
> + BIT(THS_H3_INT_CTRL_SHUT_INT_EN_OFFS)
> +#define THS_H3_INT_CTRL_DATA_IRQ_EN_OFFS 8
> +#define THS_H3_INT_CTRL_DATA_IRQ_EN \
> + BIT(THS_H3_INT_CTRL_DATA_IRQ_EN_OFFS)
> +#define THS_H3_INT_CTRL_THERMAL_PER_OFFS 12
> +#define THS_H3_INT_CTRL_THERMAL_PER(x) \
> + ((x) << THS_H3_INT_CTRL_THERMAL_PER_OFFS)
> +
> +#define THS_H3_STAT_ALARM_INT_STS_OFFS 0
> +#define THS_H3_STAT_ALARM_INT_STS \
> + BIT(THS_H3_STAT_ALARM_INT_STS_OFFS)
> +#define THS_H3_STAT_SHUT_INT_STS_OFFS 4
> +#define THS_H3_STAT_SHUT_INT_STS \
> + BIT(THS_H3_STAT_SHUT_INT_STS_OFFS)
> +#define THS_H3_STAT_DATA_IRQ_STS_OFFS 8
> +#define THS_H3_STAT_DATA_IRQ_STS \
> + BIT(THS_H3_STAT_DATA_IRQ_STS_OFFS)
> +#define THS_H3_STAT_ALARM_OFF_STS_OFFS 12
> +#define THS_H3_STAT_ALARM_OFF_STS \
> + BIT(THS_H3_STAT_ALARM_OFF_STS_OFFS)
> +
> +#define THS_H3_ALARM_CTRL_ALARM0_T_HYST_OFFS 0
> +#define THS_H3_ALARM_CTRL_ALARM0_T_HYST(x) \
> + ((x) << THS_H3_ALARM_CTRL_ALARM0_T_HYST_OFFS)
> +#define THS_H3_ALARM_CTRL_ALARM0_T_HOT_OFFS 16
> +#define THS_H3_ALARM_CTRL_ALARM0_T_HOT(x) \
> + ((x) << THS_H3_ALARM_CTRL_ALARM0_T_HOT_OFFS)
> +
> +#define THS_H3_SHUTDOWN_CTRL_SHUT0_T_HOT_OFFS 16
> +#define THS_H3_SHUTDOWN_CTRL_SHUT0_T_HOT(x) \
> + ((x) << THS_H3_SHUTDOWN_CTRL_SHUT0_T_HOT_OFFS)
> +
> +#define THS_H3_FILTER_TYPE_OFFS 0
> +#define THS_H3_FILTER_TYPE(x) \
> + ((x) << THS_H3_FILTER_TYPE_OFFS)
> +#define THS_H3_FILTER_EN_OFFS 2
> +#define THS_H3_FILTER_EN \
> + BIT(THS_H3_FILTER_EN_OFFS)

Are you using these offsets anywhere?

> +
> +#define THS_H3_CTRL0_SENSOR_ACQ0_VALUE 0xff
> +#define THS_H3_INT_CTRL_THERMAL_PER_VALUE 0x79
> +#define THS_H3_FILTER_TYPE_VALUE 0x2
> +#define THS_H3_CTRL2_SENSOR_ACQ1_VALUE 0x3f
> +
> +struct sun8i_ths_data {
> + struct sun8i_ths_type *type;
> + struct reset_control *reset;
> + struct clk *clk;
> + struct clk *busclk;
> + void __iomem *regs;
> + struct nvmem_cell *calcell;
> + struct platform_device *pdev;
> + struct thermal_zone_device *tzd;
> +};
> +
> +struct sun8i_ths_type {
> + int (*init)(struct platform_device *, struct sun8i_ths_data *);
> + int (*get_temp)(struct sun8i_ths_data *, int *out);
> + void (*irq)(struct sun8i_ths_data *);
> + void (*deinit)(struct sun8i_ths_data *);
> +};

AFAIK, you never got back on why it was actually needed, instead of
directly calling these functions.

> +/* Formula and parameters from the Allwinner 3.4 kernel */
> +static int sun8i_ths_reg_to_temperature(s32 reg, int divisor, int constant)
> +{
> + return constant - (reg * 1000000) / divisor;
> +}
> +
> +static int sun8i_ths_get_temp(void *_data, int *out)
> +{
> + struct sun8i_ths_data *data = _data;
> +
> + return data->type->get_temp(data, out);
> +}
> +
> +static irqreturn_t sun8i_ths_irq_thread(int irq, void *_data)
> +{
> + struct sun8i_ths_data *data = _data;
> +
> + data->type->irq(data);
> + thermal_zone_device_update(data->tzd);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int sun8i_ths_h3_init(struct platform_device *pdev,
> + struct sun8i_ths_data *data)
> +{
> + int ret;
> + size_t callen;
> + s32 *caldata;
> +
> + data->busclk = devm_clk_get(&pdev->dev, "ahb");
> + if (IS_ERR(data->busclk)) {
> + ret = PTR_ERR(data->busclk);
> + dev_err(&pdev->dev, "failed to get ahb clk: %d\n", ret);
> + return ret;
> + }
> +
> + data->clk = devm_clk_get(&pdev->dev, "ths");
> + if (IS_ERR(data->clk)) {
> + ret = PTR_ERR(data->clk);
> + dev_err(&pdev->dev, "failed to get ths clk: %d\n", ret);
> + return ret;
> + }
> +
> + data->reset = devm_reset_control_get(&pdev->dev, "ahb");
> + if (IS_ERR(data->reset)) {
> + ret = PTR_ERR(data->reset);
> + dev_err(&pdev->dev, "failed to get reset: %d\n", ret);
> + return ret;
> + }
> +
> + if (data->calcell) {
> + caldata = nvmem_cell_read(data->calcell, &callen);
> + if (IS_ERR(caldata))
> + return PTR_ERR(caldata);
> + writel(be32_to_cpu(*caldata), data->regs + THS_H3_CDATA);
> + kfree(caldata);
> + }
> +
> + ret = clk_prepare_enable(data->busclk);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to enable bus clk: %d\n", ret);
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(data->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to enable ths clk: %d\n", ret);
> + goto err_disable_bus;
> + }
> +
> + ret = reset_control_deassert(data->reset);
> + if (ret) {
> + dev_err(&pdev->dev, "reset deassert failed: %d\n", ret);
> + goto err_disable_ths;
> + }
> +
> + /* The final sample period is calculated as follows:
> + * (THERMAL_PER + 1) * 4096 / f_clk * 2^(FILTER_TYPE + 1)
> + *
> + * This results to about 1Hz with these settings.
> + */
> + ret = clk_set_rate(data->clk, 4000000);

I don't follow you here. You have a complicated math function, that
has many input variables, and then, you just set the clock rate to a
constant?

> + if (ret)
> + goto err_disable_ths;

A new line here please

> + writel(THS_H3_CTRL0_SENSOR_ACQ0(THS_H3_CTRL0_SENSOR_ACQ0_VALUE),
> + data->regs + THS_H3_CTRL0);
> + writel(THS_H3_INT_CTRL_THERMAL_PER(THS_H3_INT_CTRL_THERMAL_PER_VALUE) |
> + THS_H3_INT_CTRL_DATA_IRQ_EN,
> + data->regs + THS_H3_INT_CTRL);
> + writel(THS_H3_FILTER_EN | THS_H3_FILTER_TYPE(THS_H3_FILTER_TYPE_VALUE),
> + data->regs + THS_H3_FILTER);
> + writel(THS_H3_CTRL2_SENSOR_ACQ1(THS_H3_CTRL2_SENSOR_ACQ1_VALUE) |
> + THS_H3_CTRL2_SENSE_EN,
> + data->regs + THS_H3_CTRL2);

And here too.

> + return 0;
> +
> +err_disable_ths:
> + clk_disable_unprepare(data->clk);
> +err_disable_bus:
> + clk_disable_unprepare(data->busclk);
> +
> + return ret;
> +}
> +
> +static int sun8i_ths_h3_get_temp(struct sun8i_ths_data *data, int *out)
> +{
> + int val = readl(data->regs + THS_H3_DATA);
> + *out = sun8i_ths_reg_to_temperature(val, 8253, 217000);
> + return 0;

Can't you just return the value directly?

> +}
> +
> +static void sun8i_ths_h3_irq(struct sun8i_ths_data *data)
> +{
> + writel(THS_H3_STAT_DATA_IRQ_STS |
> + THS_H3_STAT_ALARM_INT_STS |
> + THS_H3_STAT_ALARM_OFF_STS |
> + THS_H3_STAT_SHUT_INT_STS,
> + data->regs + THS_H3_STAT);

So you're always clearing all the interrupts? Shouldn't you just clear
only the interrupt you received?

> +}
> +
> +static void sun8i_ths_h3_deinit(struct sun8i_ths_data *data)
> +{
> + reset_control_assert(data->reset);
> + clk_disable_unprepare(data->clk);
> + clk_disable_unprepare(data->busclk);
> +}
> +
> +static const struct thermal_zone_of_device_ops sun8i_ths_thermal_ops = {
> + .get_temp = sun8i_ths_get_temp,
> +};
> +
> +static const struct sun8i_ths_type sun8i_ths_device_h3 = {
> + .init = sun8i_ths_h3_init,
> + .get_temp = sun8i_ths_h3_get_temp,
> + .irq = sun8i_ths_h3_irq,
> + .deinit = sun8i_ths_h3_deinit,
> +};
> +
> +static const struct of_device_id sun8i_ths_id_table[] = {
> + {
> + .compatible = "allwinner,sun8i-h3-ths",
> + .data = &sun8i_ths_device_h3,
> + },
> + {
> + /* sentinel */
> + },
> +};
> +MODULE_DEVICE_TABLE(of, sun8i_ths_id_table);
> +
> +static int sun8i_ths_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + const struct of_device_id *match;
> + struct sun8i_ths_data *data;
> + struct resource *res;
> + int ret;
> + int irq;
> +
> + match = of_match_node(sun8i_ths_id_table, np);

If you *really* need to (but I still don't really see why), you can
use of_device_get_match_data here.

> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->type = (struct sun8i_ths_type *)match->data;
> + data->pdev = pdev;
> +
> + data->calcell = devm_nvmem_cell_get(&pdev->dev, "calibration");
> + if (IS_ERR(data->calcell)) {
> + if (PTR_ERR(data->calcell) == -EPROBE_DEFER)
> + return PTR_ERR(data->calcell);

New line

> + data->calcell = NULL; /* No calibration register */

s/register/data/ ?

> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + data->regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(data->regs)) {
> + ret = PTR_ERR(data->regs);
> + dev_err(&pdev->dev,
> + "failed to ioremap THS registers: %d\n", ret);
> + return ret;
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "failed to get IRQ: %d\n", irq);
> + return irq;
> + }
> +
> + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
> + sun8i_ths_irq_thread, IRQF_ONESHOT,
> + dev_name(&pdev->dev), data);

Why a threaded irq?

> + if (ret)
> + return ret;
> +
> + ret = data->type->init(pdev, data);
> + if (ret)
> + return ret;
> +
> + data->tzd = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
> + &sun8i_ths_thermal_ops);
> + if (IS_ERR(data->tzd)) {
> + ret = PTR_ERR(data->tzd);
> + dev_err(&pdev->dev, "failed to register thermal zone: %d\n",
> + ret);
> + goto err_deinit;
> + }
> +
> + platform_set_drvdata(pdev, data);
> + return 0;
> +
> +err_deinit:
> + data->type->deinit(data);
> + return ret;
> +}
> +
> +static int sun8i_ths_remove(struct platform_device *pdev)
> +{
> + struct sun8i_ths_data *data = platform_get_drvdata(pdev);
> +
> + thermal_zone_of_sensor_unregister(&pdev->dev, data->tzd);
> + data->type->deinit(data);
> + return 0;
> +}
> +
> +static struct platform_driver sun8i_ths_driver = {
> + .probe = sun8i_ths_probe,
> + .remove = sun8i_ths_remove,
> + .driver = {
> + .name = "sun8i_ths",
> + .of_match_table = sun8i_ths_id_table,
> + },
> +};
> +
> +module_platform_driver(sun8i_ths_driver);
> +
> +MODULE_AUTHOR("Josef Gajdusek <atx@atx.name>");
> +MODULE_DESCRIPTION("Sunxi THS driver");

Please change the description here too to match the header.

Thanks!
Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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