On Wed, Jun 16, 2021 at 08:15:45PM +0200, Emil Renner Berthing wrote:
> Register definitions based on sfctemp driver in the StarFive
> 5.10 kernel by Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>.
>
> Signed-off-by: Emil Renner Berthing <kernel@xxxxxxxx>
> ---
>
> @Samin: Only the register definitions and conversion constants are left
> from your driver, but still it would be really nice if you could reply
> to this mail with your Signed-off-by. Thanks!
>
>
> drivers/hwmon/Kconfig | 9 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/sfctemp.c | 309 ++++++++++++++++++++++++++++++++++++++++
Documentation/hwmon/sfctemp is missing.
> 3 files changed, 319 insertions(+)
> create mode 100644 drivers/hwmon/sfctemp.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 87624902ea80..fa7562920dfa 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1751,6 +1751,15 @@ config SENSORS_STTS751
> This driver can also be built as a module. If so, the module
> will be called stts751.
>
> +config SENSORS_SFCTEMP
> + tristate "Starfive JH7100 temperature sensor"
> + help
> + If you say yes here you get support for temperature sensor
> + on the Starfive JH7100 SoC.
> +
> + This driver can also be built as a module. If so, the module
> + will be called sfctemp.
> +
> config SENSORS_SMM665
> tristate "Summit Microelectronics SMM665"
> depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 59e78bc212cf..3723eb580bf3 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -167,6 +167,7 @@ obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o
> obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o
> obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o
> obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o
> +obj-$(CONFIG_SENSORS_SFCTEMP) += sfctemp.o
> obj-$(CONFIG_SENSORS_SL28CPLD) += sl28cpld-hwmon.o
> obj-$(CONFIG_SENSORS_SHT15) += sht15.o
> obj-$(CONFIG_SENSORS_SHT21) += sht21.o
> diff --git a/drivers/hwmon/sfctemp.c b/drivers/hwmon/sfctemp.c
> new file mode 100644
> index 000000000000..62a838063e4e
> --- /dev/null
> +++ b/drivers/hwmon/sfctemp.c
> @@ -0,0 +1,309 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Emil Renner Berthing <kernel@xxxxxxxx>
> + * Copyright (C) 2021 Samin Guo <samin.guo@xxxxxxxxxxxxxxxx>
> + */
> +#include <linux/completion.h>
> +#include <linux/delay.h>
> +#include <linux/hwmon.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
This may work on some systems, but on others it will result in:
drivers/hwmon/sfctemp.c: In function ‘sfctemp_power_up’:
drivers/hwmon/sfctemp.c:76:2: error: implicit declaration of function ‘writel’
drivers/hwmon/sfctemp.c: In function ‘sfctemp_convert’:
drivers/hwmon/sfctemp.c:144:17: error: implicit declaration of function ‘readl’
It is necessary to include <linux/io.h>.
> +
> +/* TempSensor reset. The RSTN can be de-asserted once the analog core has
> + * powered up. Trst(min 100ns)
> + * 0:reset 1:de-assert */
/*
* Please use standard multi-line comments.
* checkpatch would tell you, plus it has other complaints.
* Please run checkpatch --strict and fix what it reports.
*/
> +#define SFCTEMP_RSTN BIT(0)
> +
> +/* TempSensor analog core power down. The analog core will be powered up
> + * Tpu(min 50us) after PD is de-asserted. RSTN should be held low until the
> + * analog core is powered up.
> + * 0:power up 1:power down */
> +#define SFCTEMP_PD BIT(1)
> +
> +/* TempSensor start conversion enable.
> + * 0:disable 1:enable */
> +#define SFCTEMP_RUN BIT(2)
> +
> +/* TempSensor calibration mode enable.
> + * 0:disable 1:enable */
> +#define SFCTEMP_CAL BIT(4)
> +
> +/* TempSensor signature enable. Generate a toggle value outputting on DOUT for
> + * test purpose.
> + * 0:disable 1:enable */
> +#define SFCTEMP_SGN BIT(5)
> +
> +/* TempSensor test access control.
> + * 0000:normal 0001:Test1 0010:Test2 0011:Test3
> + * 0100:Test4 1000:Test8 1001:Test9 */
> +#define SFCTEMP_TM_Pos 12
> +#define SFCTEMP_TM_Msk GENMASK(15, 12)
Defines should upper case. Besides, the above defines are not
used. Please remove unused defines, and please rename the others
to be upper case only.
> +
> +/* TempSensor conversion value output.
> + * Temp(c)=DOUT*Y/4094 - K */
> +#define SFCTEMP_DOUT_Pos 16
> +#define SFCTEMP_DOUT_Msk GENMASK(27, 16)
> +
> +/* TempSensor digital test output. */
> +#define SFCTEMP_DIGO BIT(31)
> +
> +/* DOUT to Celcius conversion constants */
> +#define SFCTEMP_Y1000 237500L
> +#define SFCTEMP_Z 4094L
Please use
#define<space><definition><tab><value>, eg
#define SFCTEMP_Y1000 237500L
#define SFCTEMP_Z 4094L
for all defines.
> +#define SFCTEMP_K1000 81100L
> +
> +struct sfctemp {
> + struct mutex lock;
> + struct completion conversion_done;
> + void __iomem *regs;
> + bool enabled;
> +};
> +
> +static irqreturn_t sfctemp_isr(int irq, void *data)
> +{
> + struct sfctemp *sfctemp = data;
> +
> + complete(&sfctemp->conversion_done);
> + return IRQ_HANDLED;
> +}
> +
> +static void sfctemp_power_up(struct sfctemp *sfctemp)
> +{
> + /* make sure we're powered down first */
> + writel(SFCTEMP_PD, sfctemp->regs);
> + udelay(1);
> +
> + writel(0, sfctemp->regs);
> + /* wait t_pu(50us) + t_rst(100ns) */
> + usleep_range(60, 200);
> +
> + /* de-assert reset */
> + writel(SFCTEMP_RSTN, sfctemp->regs);
> + udelay(1); /* wait t_su(500ps) */
> +}
> +
> +static void sfctemp_power_down(struct sfctemp *sfctemp)
> +{
> + writel(SFCTEMP_PD, sfctemp->regs);
> +}
> +
> +static void sfctemp_run_single(struct sfctemp *sfctemp)
> +{
> + writel(SFCTEMP_RSTN | SFCTEMP_RUN, sfctemp->regs);
> + udelay(1);
> + writel(SFCTEMP_RSTN, sfctemp->regs);
> +}
> +
> +static int sfctemp_enable(struct sfctemp *sfctemp)
> +{
> + mutex_lock(&sfctemp->lock);
> + if (sfctemp->enabled)
> + goto done;
> +
> + sfctemp_power_up(sfctemp);
> + sfctemp->enabled = true;
> +done:
> + mutex_unlock(&sfctemp->lock);
> + return 0;
> +}
> +
> +static int sfctemp_disable(struct sfctemp *sfctemp)
> +{
> + mutex_lock(&sfctemp->lock);
> + if (!sfctemp->enabled)
> + goto done;
> +
> + sfctemp_power_down(sfctemp);
> + sfctemp->enabled = false;
> +done:
> + mutex_unlock(&sfctemp->lock);
> + return 0;
> +}
> +
> +static int sfctemp_convert(struct sfctemp *sfctemp, long *val)
> +{
> + long ret;
Why long ? Sure, wait_for_completion_interruptible_timeout()
returns a long, but it will never return a value large enough to warrant
a long here.
> +
> + mutex_lock(&sfctemp->lock);
> + if (!sfctemp->enabled) {
> + ret = -ENODATA;
> + goto out;
> + }
> +
> + sfctemp_run_single(sfctemp);
> +
> + ret = wait_for_completion_interruptible_timeout(&sfctemp->conversion_done,
> + msecs_to_jiffies(10));
> + if (ret < 0)
> + goto out;
> +
> + /* calculate temperature in milli Celcius */
> + *val = (long)((readl(sfctemp->regs) & SFCTEMP_DOUT_Msk) >> SFCTEMP_DOUT_Pos)
> + * SFCTEMP_Y1000 / SFCTEMP_Z - SFCTEMP_K1000;
> +
> + ret = 0;
> +out:
> + mutex_unlock(&sfctemp->lock);
> + return ret;
> +}
> +
> +static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_enable:
> + return 0644;
> + case hwmon_temp_input:
> + return 0444;
> + }
> + return 0;
> + default:
> + return 0;
> + }
> +}
> +
> +static int sfctemp_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct sfctemp *sfctemp = dev_get_drvdata(dev);
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_enable:
> + *val = sfctemp->enabled;
> + return 0;
> + case hwmon_temp_input:
> + return sfctemp_convert(sfctemp, val);
> + }
> + return -EINVAL;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int sfctemp_write(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long val)
> +{
> + struct sfctemp *sfctemp = dev_get_drvdata(dev);
> +
> + switch (type) {
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_enable:
> + if (val == 0)
> + return sfctemp_disable(sfctemp);
> + if (val == 1)
> + return sfctemp_enable(sfctemp);
> + break;
> + }
> + return -EINVAL;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct hwmon_channel_info *sfctemp_info[] = {
> + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
> + HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT),
> + NULL
> +};
> +
> +static const struct hwmon_ops sfctemp_hwmon_ops = {
> + .is_visible = sfctemp_is_visible,
> + .read = sfctemp_read,
> + .write = sfctemp_write,
> +};
> +
> +static const struct hwmon_chip_info sfctemp_chip_info = {
> + .ops = &sfctemp_hwmon_ops,
> + .info = sfctemp_info,
> +};
> +
> +static int sfctemp_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device *hwmon_dev;
> + struct resource *mem;
> + struct sfctemp *sfctemp;
> + long val;
> + int ret;
> +
> + sfctemp = devm_kzalloc(dev, sizeof(*sfctemp), GFP_KERNEL);
> + if (!sfctemp)
> + return -ENOMEM;
> +
> + dev_set_drvdata(dev, sfctemp);
> + mutex_init(&sfctemp->lock);
> + init_completion(&sfctemp->conversion_done);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + sfctemp->regs = devm_ioremap_resource(dev, mem);
> + if (IS_ERR(sfctemp->regs))
> + return PTR_ERR(sfctemp->regs);
> +
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + return ret;
> +
> + ret = devm_request_irq(dev, ret, sfctemp_isr,
> + IRQF_SHARED, pdev->name, sfctemp);
> + if (ret) {
> + dev_err(dev, "request irq failed: %d\n", ret);
> + return ret;
> + }
> +
> + ret = sfctemp_enable(sfctemp);
> + if (ret)
> + return ret;
Please consider adding devm_add_action_or_reset() to disable the sensor.
Then you can use devm_hwmon_device_register_with_info(), and there is
no need for a remove function.
> +
> + hwmon_dev = hwmon_device_register_with_info(dev, pdev->name, sfctemp,
> + &sfctemp_chip_info, NULL);
> + if (IS_ERR(hwmon_dev))
> + return PTR_ERR(hwmon_dev);
> +
> + /* do a conversion to check everything works */
> + ret = sfctemp_convert(sfctemp, &val);
Please drop this check; it will result in substantial boot delays.
The assumption is the the hardware works; the system should not be
optimized (slowed down) to handle a potential and hopefully rare
failure case.
> + if (ret) {
> + hwmon_device_unregister(hwmon_dev);
> + return ret;
> + }
> +
> + dev_info(dev, "%ld.%03ld C\n", val / 1000, val % 1000);
Please drop this message. Anyone interested in boot-time temperature
readings can add a script and get it from sysfs attributes as needed.
> + return 0;
> +}
> +
> +static int sfctemp_remove(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct sfctemp *sfctemp = dev_get_drvdata(dev);
> +
> + hwmon_device_unregister(dev);
> + return sfctemp_disable(sfctemp);
> +}
> +
> +static const struct of_device_id sfctemp_of_match[] = {
> + { .compatible = "starfive,jh7100-temp" },
> + { /* sentinel */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, sfctemp_of_match);
> +
> +static struct platform_driver sfctemp_driver = {
> + .driver = {
> + .name = "sfctemp",
> + .of_match_table = of_match_ptr(sfctemp_of_match),
> + },
> + .probe = sfctemp_probe,
> + .remove = sfctemp_remove,
> +};
> +module_platform_driver(sfctemp_driver);
> +
> +MODULE_AUTHOR("Emil Renner Berthing");
> +MODULE_DESCRIPTION("StarFive JH7100 temperature sensor driver");
> +MODULE_LICENSE("GPL");
> --
> 2.32.0
>
