Hi,
On Wed, Feb 10, 2016 at 11:33:43PM +0000, Adam Baker wrote:
> Create a driver to support the hardware monitoring chip present in
> several models of Zyxel NSA3xx NAS devices.
>
> The driver reads fan speed and temperature from a suitably programmed
> MCU on the device.
>
> Signed-off-by: Adam Baker <linux@xxxxxxxxxxxxxxxx>
Please name the driver nsa320. It may ultimately support other devices,
but that doesn't mean it is going to support NSA-35x or other future
similar devices.
Got the headline, please use
hwmon: Add driver for Zyxel NSA-320
> ---
> I've tested this on an NSA-320, I've had someone offer to test it on
> NSA-325 so hopefully I will get a tested by back.
> ---
> drivers/hwmon/Kconfig | 13 +++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/nsa3xx-hwmon.c | 223 +++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 237 insertions(+)
> create mode 100644 drivers/hwmon/nsa3xx-hwmon.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 80a73bf..8801b78 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1757,6 +1757,19 @@ config SENSORS_ULTRA45
> This driver provides support for the Ultra45 workstation environmental
> sensors.
>
> +config SENSORS_NSA3XX
Please try to stick with alphabetic order.
> + tristate "ZyXEL NSA3xx fan speed and temperature sensors"
... NSA-320 and compatible ...
> + depends on GPIOLIB && OF
Can you add some additional dependencies ?
It is quite unlikely that the driver is needed on an X86.
Please use at least
depends on ARM || COMPILE_TEST
or a more specific dependency if the SoC is known. MACH_KIRKWOOD, maybe ?
> + help
> + If you say yes here you get support for hardware monitoring
> + for the ZyXEL NSA3XX Media Servers.
Please be specific which devices are supported. Feel free to add "and
compatibles", but please no generic and misleading statements such as 3XX.
> +
> + The sensor data is taken from a Holtek HT46R065 microcontroller
> + connected to GPIO lines.
> +
Is that relevant ?
> + This driver can also be built as a module. If so, the module
> + will be called nsa3xx-hwmon.
> +
> if ACPI
>
> comment "ACPI drivers"
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 12a3239..e85414a 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -118,6 +118,7 @@ obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
> obj-$(CONFIG_SENSORS_MAX6697) += max6697.o
> obj-$(CONFIG_SENSORS_MAX31790) += max31790.o
> obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
> +obj-$(CONFIG_SENSORS_NSA3XX) += nsa3xx-hwmon.o
Please try to stick with alphabetic order.
> obj-$(CONFIG_SENSORS_MCP3021) += mcp3021.o
> obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
> obj-$(CONFIG_SENSORS_NCT6683) += nct6683.o
> diff --git a/drivers/hwmon/nsa3xx-hwmon.c b/drivers/hwmon/nsa3xx-hwmon.c
> new file mode 100644
> index 0000000..0fbf118
> --- /dev/null
> +++ b/drivers/hwmon/nsa3xx-hwmon.c
nsa320-hwmon.c
> @@ -0,0 +1,223 @@
> +/*
> + * drivers/hwmon/nsa3xx-hwmon.c
> + *
> + * ZyXEL NSA3xx Media Servers
Please be specific.
> + * hardware monitoring
> + *
> + * Copyright (C) 2016 Adam Baker <linux@xxxxxxxxxxxxxxxx>
> + * based on a board file driver
> + * Copyright (C) 2012 Peter Schildmann <linux@xxxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License v2 as published by the
> + * Free Software Foundation.
> + *
> + * 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/module.h>
> +#include <linux/mutex.h>
> +#include <linux/platform_device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.h>
> +#include <linux/jiffies.h>
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +
Please order include files alphabetically.
> +#define MAGIC_NUMBER 0x55
> +
> +/*
> + * The Zyxel hwmon MCU is a Holtek HT46R065 that is factory programmed
> + * to perform temperature and fan speed monitoring. It is read by taking
> + * the active pin low. The 32 bit output word is then clocked onto the
> + * data line. The MSB of the data word is a magic nuber to indicate it
> + * has been read correctly, the next byte is the fan speed (in hundreds
> + * of RPM) and the last two bytes are the temperature (in tenths of a
> + * degree)
> + */
> +
> +struct nsa3xx_hwmon {
s/nsa3xx/nsa320/g for the entire file, please.
> + struct device *classdev;
> + struct mutex update_lock; /* lock GPIO operations */
> + unsigned long last_updated; /* jiffies */
> + u32 mcu_data;
I would suggest to use unsigned long here. See below for reasons.
> + struct gpio_desc *act;
> + struct gpio_desc *clk;
> + struct gpio_desc *data;
> +};
> +
> +enum nsa3xx_inputs {
> + NSA3XX_FAN = 1,
> + NSA3XX_TEMP = 0,
Any special reason for the unusual order ? If yes, please explain.
> +};
> +
> +static const char * const nsa3xx_input_names[] = {
> + [NSA3XX_FAN] = "Chassis Fan",
> + [NSA3XX_TEMP] = "System Temperature",
> +};
> +
> +/* Although this protocol looks similar to SPI the long delay
> + * between the active (aka chip select) signal and the shorter
> + * delay between clock pulses are needed for reliable operation.
> + * The delays provided are taken from the manufacturer kernel,
> + * testing suggest they probably incorporate a reasonable safety
> + * margin. (The single device tested became unreliable if the
> + * delay was reduced to 1/10th of this value.)
> + */
> +static unsigned long nsa3xx_hwmon_update(struct device *dev)
> +{
> + u32 mcu_data;
> + u32 mask;
> + struct nsa3xx_hwmon *hwmon = dev_get_drvdata(dev);
> +
> + mutex_lock(&hwmon->update_lock);
> +
> + mcu_data = hwmon->mcu_data;
> +
> + if (time_after(jiffies, hwmon->last_updated + HZ) ||
> + mcu_data == 0) {
> +
Please no blank line here. Also, please align continuation lines with '('.
However, unless I am missing something, the continuation line is not needed
in the first place. Please no unnecessary continuation lines.
> + gpiod_set_value(hwmon->act, 1);
> + msleep(100);
> +
> + for (mask = BIT(31); mask; mask >>= 1) {
Since you are using BIT(), please include linux/bitops.h.
> + gpiod_set_value(hwmon->clk, 0);
> + usleep_range(100, 200);
> + gpiod_set_value(hwmon->clk, 1);
> + usleep_range(100, 200);
> + if (gpiod_get_value(hwmon->data))
> + mcu_data |= mask;
> + }
> +
> + gpiod_set_value(hwmon->act, 0);
> + dev_dbg(dev, "Read raw MCU data %08x\n", mcu_data);
> +
> + if ((mcu_data >> 24) != MAGIC_NUMBER) {
> + dev_err(dev, "Read invalid MCU data %08x\n", mcu_data);
> + mcu_data = 0;
Instead of an error message, it would be better to return an error code
(probably -EIO since we don't know better).
The calling code can then return the error to user space.
> + }
> +
> + hwmon->mcu_data = mcu_data;
> + hwmon->last_updated = jiffies;
> + }
> +
> + mutex_unlock(&hwmon->update_lock);
> +
> + return mcu_data;
> +}
> +
> +static ssize_t show_label(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int channel = to_sensor_dev_attr(attr)->index;
> +
> + return sprintf(buf, "%s\n", nsa3xx_input_names[channel]);
> +}
> +
> +static ssize_t show_value(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int channel = to_sensor_dev_attr(attr)->index;
> + unsigned long mcu_data = nsa3xx_hwmon_update(dev);
> + unsigned long value = 0;
> +
If nsa3xx_hwmon_update() returns an error code, you can use
if (IS_ERR_VALUE(mcu_data))
return (long)mcu_data;
or even better have nsa3xx_hwmon_update() return int directly
to indicate an error.
> + pr_debug("channel value 0x%02x!\n", channel);
Is this really useful ? I would suggest to drop debug messages
unless really needed. If you really think the message is useful,
please use dev_dbg().
> + switch (channel) {
> + case NSA3XX_TEMP:
> + value = (mcu_data & 0xffff) * 100;
> + break;
> + case NSA3XX_FAN:
> + value = ((mcu_data & 0xff0000) >> 16) * 100;
> + break;
> + }
> + return sprintf(buf, "%lu\n", value);
> +}
> +
> +static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, NSA3XX_TEMP);
> +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_value, NULL, NSA3XX_TEMP);
> +static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, show_label, NULL, NSA3XX_FAN);
> +static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_value, NULL, NSA3XX_FAN);
> +
> +static struct attribute *nsa3xx_attrs[] = {
> + &sensor_dev_attr_temp1_label.dev_attr.attr,
> + &sensor_dev_attr_temp1_input.dev_attr.attr,
> + &sensor_dev_attr_fan1_label.dev_attr.attr,
> + &sensor_dev_attr_fan1_input.dev_attr.attr,
> + NULL
> +};
> +
> +ATTRIBUTE_GROUPS(nsa3xx);
> +
> +static const struct of_device_id of_nsa3xx_hwmon_match[] = {
> + { .compatible = "zyxel,nsa320-mcu", },
> + { },
> +};
> +
> +static int nsa3xx_hwmon_probe(struct platform_device *pdev)
> +{
> + struct nsa3xx_hwmon *hwmon;
> +
> + hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
> + if (!hwmon)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, hwmon);
Unnecessary.
> +
> + /* Look up the GPIO pins to use */
> + hwmon->act = devm_gpiod_get(&pdev->dev, "act", GPIOD_OUT_LOW);
> + hwmon->clk = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_HIGH);
> + hwmon->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN);
> +
> + if (IS_ERR(hwmon->act))
> + return PTR_ERR(hwmon->act);
> + if (IS_ERR(hwmon->clk))
> + return PTR_ERR(hwmon->clk);
> + if (IS_ERR(hwmon->data))
> + return PTR_ERR(hwmon->data);
Please reorder to have the error checks immediately after the calls
to devm_gpiod_get().
> +
> + mutex_init(&hwmon->update_lock);
> +
> + hwmon->classdev = devm_hwmon_device_register_with_groups(&pdev->dev,
> + "nsa3xx", hwmon, nsa3xx_groups);
classdev is only used in this function and thus does not have to be kept
in struct nsa3xx_hwmon.
> + if (IS_ERR(hwmon->classdev))
> + return PTR_ERR(hwmon->classdev);
> +
> + dev_dbg(&pdev->dev, "initialized\n");
> +
This message is really unnecessary. Please just use
return PTR_ERR_OR_ZERO(classdev);
> + return 0;
> +}
> +
> +static int nsa3xx_hwmon_remove(struct platform_device *pdev)
> +{
> + /* All resources are allocated with devm_*() so
> + * there is nothing to do here.
> + */
> +
> + return 0;
> +}
If the remove function is not needed, it is not needed and should not
exist in the first place. Please no dummy functions.
> +
> +static struct platform_driver nsa3xx_hwmon_driver = {
> + .probe = nsa3xx_hwmon_probe,
> + .remove = nsa3xx_hwmon_remove,
> + .driver = {
> + .name = "nsa3xx-hwmon",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(of_nsa3xx_hwmon_match),
> + },
> +};
> +
> +module_platform_driver(nsa3xx_hwmon_driver);
> +
> +MODULE_DEVICE_TABLE(of, of_nsa3xx_hwmon_match);
> +MODULE_AUTHOR("Peter Schildmann <linux@xxxxxxxxxxxxxxx>");
> +MODULE_AUTHOR("Adam Baker <linux@xxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("NSA3XX Hardware Monitoring");
> +MODULE_LICENSE("GPL");
GPL v2
> +MODULE_ALIAS("platform:nsa3xx-hwmon");
> --
> 2.1.4
>
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
