diff options
| -rw-r--r-- | Documentation/hwmon/nsa320 | 53 | ||||
| -rw-r--r-- | drivers/hwmon/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/hwmon/Makefile | 1 | ||||
| -rw-r--r-- | drivers/hwmon/nsa320-hwmon.c | 215 |
4 files changed, 284 insertions, 0 deletions
diff --git a/Documentation/hwmon/nsa320 b/Documentation/hwmon/nsa320 new file mode 100644 index 000000000000..fdbd6947799b --- /dev/null +++ b/Documentation/hwmon/nsa320 @@ -0,0 +1,53 @@ +Kernel driver nsa320_hwmon +========================== + +Supported chips: + * Holtek HT46R065 microcontroller with onboard firmware that configures + it to act as a hardware monitor. + Prefix: 'nsa320' + Addresses scanned: none + Datasheet: Not available, driver was reverse engineered based upon the + Zyxel kernel source + +Author: + Adam Baker <linux@baker-net.org.uk> + +Description +----------- + +This chip is known to be used in the Zyxel NSA320 and NSA325 NAS Units and +also in some variants of the NSA310 but the driver has only been tested +on the NSA320. In all of these devices it is connected to the same 3 GPIO +lines which are used to provide chip select, clock and data lines. The +interface behaves similarly to SPI but at much lower speeds than are normally +used for SPI. + +Following each chip select pulse the chip will generate a single 32 bit word +that contains 0x55 as a marker to indicate that data is being read correctly, +followed by an 8 bit fan speed in 100s of RPM and a 16 bit temperature in +tenths of a degree. + + +sysfs-Interface +--------------- + +temp1_input - temperature input +fan1_input - fan speed + +Notes +----- + +The access timings used in the driver are the same as used in the Zyxel +provided kernel. Testing has shown that if the delay between chip select and +the first clock pulse is reduced from 100 ms to just under 10ms then the chip +will not produce any output. If the duration of either phase of the clock +is reduced from 100 us to less than 15 us then data pulses are likely to be +read twice corrupting the output. The above analysis is based upon a sample +of one unit but suggests that the Zyxel provided delay values include a +reasonable tolerance. + +The driver incorporates a limit that it will not check for updated values +faster than once a second. This is because the hardware takes a relatively long +time to read the data from the device and when it does it reads both temp and +fan speed. As the most likely case for two accesses in quick succession is +to read both of these values avoiding a second read delay is desirable. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 7a437ce99cf2..5c2d13a687aa 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1190,6 +1190,21 @@ config SENSORS_NCT7904 This driver can also be built as a module. If so, the module will be called nct7904. +config SENSORS_NSA320 + tristate "ZyXEL NSA320 and compatible fan speed and temperature sensors" + depends on GPIOLIB && OF + depends on MACH_KIRKWOOD || COMPILE_TEST + help + If you say yes here you get support for hardware monitoring + for the ZyXEL NSA320 Media Server and other compatible devices + (probably the NSA325 and some NSA310 variants). + + The sensor data is taken from a Holtek HT46R065 microcontroller + connected to GPIO lines. + + This driver can also be built as a module. If so, the module + will be called nsa320-hwmon. + config SENSORS_PCF8591 tristate "Philips PCF8591 ADC/DAC" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index a7ecaf2f29aa..58cc3acba7e7 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -124,6 +124,7 @@ obj-$(CONFIG_SENSORS_NCT6683) += nct6683.o obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o obj-$(CONFIG_SENSORS_NCT7802) += nct7802.o obj-$(CONFIG_SENSORS_NCT7904) += nct7904.o +obj-$(CONFIG_SENSORS_NSA320) += nsa320-hwmon.o obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o obj-$(CONFIG_SENSORS_PC87360) += pc87360.o obj-$(CONFIG_SENSORS_PC87427) += pc87427.o diff --git a/drivers/hwmon/nsa320-hwmon.c b/drivers/hwmon/nsa320-hwmon.c new file mode 100644 index 000000000000..0517a265741f --- /dev/null +++ b/drivers/hwmon/nsa320-hwmon.c @@ -0,0 +1,215 @@ +/* + * drivers/hwmon/nsa320-hwmon.c + * + * ZyXEL NSA320 Media Servers + * hardware monitoring + * + * Copyright (C) 2016 Adam Baker <linux@baker-net.org.uk> + * based on a board file driver + * Copyright (C) 2012 Peter Schildmann <linux@schildmann.info> + * + * 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/bitops.h> +#include <linux/delay.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/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> + +/* Tests for error return values rely upon this value being < 0x80 */ +#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 nsa320_hwmon { + struct mutex update_lock; /* lock GPIO operations */ + unsigned long last_updated; /* jiffies */ + unsigned long mcu_data; + struct gpio_desc *act; + struct gpio_desc *clk; + struct gpio_desc *data; +}; + +enum nsa320_inputs { + NSA320_TEMP = 0, + NSA320_FAN = 1, +}; + +static const char * const nsa320_input_names[] = { + [NSA320_TEMP] = "System Temperature", + [NSA320_FAN] = "Chassis Fan", +}; + +/* + * 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 s32 nsa320_hwmon_update(struct device *dev) +{ + u32 mcu_data; + u32 mask; + struct nsa320_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) { + gpiod_set_value(hwmon->act, 1); + msleep(100); + + mcu_data = 0; + for (mask = BIT(31); mask; mask >>= 1) { + 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_dbg(dev, "Read invalid MCU data %08x\n", mcu_data); + mcu_data = -EIO; + } else { + 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", nsa320_input_names[channel]); +} + +static ssize_t show_temp(struct device *dev, struct device_attribute *attr, + char *buf) +{ + s32 mcu_data = nsa320_hwmon_update(dev); + + if (mcu_data < 0) + return mcu_data; + + return sprintf(buf, "%d\n", (mcu_data & 0xffff) * 100); +} + +static ssize_t show_fan(struct device *dev, struct device_attribute *attr, + char *buf) +{ + s32 mcu_data = nsa320_hwmon_update(dev); + + if (mcu_data < 0) + return mcu_data; + + return sprintf(buf, "%d\n", ((mcu_data & 0xff0000) >> 16) * 100); +} + +static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, NSA320_TEMP); +static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL); +static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, show_label, NULL, NSA320_FAN); +static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL); + +static struct attribute *nsa320_attrs[] = { + &sensor_dev_attr_temp1_label.dev_attr.attr, + &dev_attr_temp1_input.attr, + &sensor_dev_attr_fan1_label.dev_attr.attr, + &dev_attr_fan1_input.attr, + NULL +}; + +ATTRIBUTE_GROUPS(nsa320); + +static const struct of_device_id of_nsa320_hwmon_match[] = { + { .compatible = "zyxel,nsa320-mcu", }, + { }, +}; + +static int nsa320_hwmon_probe(struct platform_device *pdev) +{ + struct nsa320_hwmon *hwmon; + struct device *classdev; + + hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL); + if (!hwmon) + return -ENOMEM; + + /* Look up the GPIO pins to use */ + hwmon->act = devm_gpiod_get(&pdev->dev, "act", GPIOD_OUT_LOW); + if (IS_ERR(hwmon->act)) + return PTR_ERR(hwmon->act); + + hwmon->clk = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_HIGH); + if (IS_ERR(hwmon->clk)) + return PTR_ERR(hwmon->clk); + + hwmon->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN); + if (IS_ERR(hwmon->data)) + return PTR_ERR(hwmon->data); + + mutex_init(&hwmon->update_lock); + + classdev = devm_hwmon_device_register_with_groups(&pdev->dev, + "nsa320", hwmon, nsa320_groups); + + return PTR_ERR_OR_ZERO(classdev); + +} + +/* All allocations use devres so remove() is not needed. */ + +static struct platform_driver nsa320_hwmon_driver = { + .probe = nsa320_hwmon_probe, + .driver = { + .name = "nsa320-hwmon", + .of_match_table = of_match_ptr(of_nsa320_hwmon_match), + }, +}; + +module_platform_driver(nsa320_hwmon_driver); + +MODULE_DEVICE_TABLE(of, of_nsa320_hwmon_match); +MODULE_AUTHOR("Peter Schildmann <linux@schildmann.info>"); +MODULE_AUTHOR("Adam Baker <linux@baker-net.org.uk>"); +MODULE_DESCRIPTION("NSA320 Hardware Monitoring"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:nsa320-hwmon"); |