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authorAdam Baker <linux@baker-net.org.uk>2016-03-05 10:34:56 -0500
committerGuenter Roeck <linux@roeck-us.net>2016-03-08 21:40:49 -0500
commit630300d5fcb6ee9c32c75d8b576c100fbb794159 (patch)
treec8d04457a2c27f3d71a3e43af093fa2af741c3d8
parent8d801243192f4dca693f9ff0c7953ff2ce01164d (diff)
hwmon: Create an NSA320 hardware monitoring driver
Create a driver to support the hardware monitoring chip present in the Zyxel NSA320 and some of the other Zyxel NAS devices. The driver reads fan speed and temperature from a suitably pre-programmed MCU on the device. Signed-off-by: Adam Baker <linux@baker-net.org.uk> [groeck: Dropped .owner field initialization] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat
-rw-r--r--Documentation/hwmon/nsa32053
-rw-r--r--drivers/hwmon/Kconfig15
-rw-r--r--drivers/hwmon/Makefile1
-rw-r--r--drivers/hwmon/nsa320-hwmon.c215
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 @@
1Kernel driver nsa320_hwmon
2==========================
3
4Supported chips:
5 * Holtek HT46R065 microcontroller with onboard firmware that configures
6 it to act as a hardware monitor.
7 Prefix: 'nsa320'
8 Addresses scanned: none
9 Datasheet: Not available, driver was reverse engineered based upon the
10 Zyxel kernel source
11
12Author:
13 Adam Baker <linux@baker-net.org.uk>
14
15Description
16-----------
17
18This chip is known to be used in the Zyxel NSA320 and NSA325 NAS Units and
19also in some variants of the NSA310 but the driver has only been tested
20on the NSA320. In all of these devices it is connected to the same 3 GPIO
21lines which are used to provide chip select, clock and data lines. The
22interface behaves similarly to SPI but at much lower speeds than are normally
23used for SPI.
24
25Following each chip select pulse the chip will generate a single 32 bit word
26that contains 0x55 as a marker to indicate that data is being read correctly,
27followed by an 8 bit fan speed in 100s of RPM and a 16 bit temperature in
28tenths of a degree.
29
30
31sysfs-Interface
32---------------
33
34temp1_input - temperature input
35fan1_input - fan speed
36
37Notes
38-----
39
40The access timings used in the driver are the same as used in the Zyxel
41provided kernel. Testing has shown that if the delay between chip select and
42the first clock pulse is reduced from 100 ms to just under 10ms then the chip
43will not produce any output. If the duration of either phase of the clock
44is reduced from 100 us to less than 15 us then data pulses are likely to be
45read twice corrupting the output. The above analysis is based upon a sample
46of one unit but suggests that the Zyxel provided delay values include a
47reasonable tolerance.
48
49The driver incorporates a limit that it will not check for updated values
50faster than once a second. This is because the hardware takes a relatively long
51time to read the data from the device and when it does it reads both temp and
52fan speed. As the most likely case for two accesses in quick succession is
53to 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
1190 This driver can also be built as a module. If so, the module 1190 This driver can also be built as a module. If so, the module
1191 will be called nct7904. 1191 will be called nct7904.
1192 1192
1193config SENSORS_NSA320
1194 tristate "ZyXEL NSA320 and compatible fan speed and temperature sensors"
1195 depends on GPIOLIB && OF
1196 depends on MACH_KIRKWOOD || COMPILE_TEST
1197 help
1198 If you say yes here you get support for hardware monitoring
1199 for the ZyXEL NSA320 Media Server and other compatible devices
1200 (probably the NSA325 and some NSA310 variants).
1201
1202 The sensor data is taken from a Holtek HT46R065 microcontroller
1203 connected to GPIO lines.
1204
1205 This driver can also be built as a module. If so, the module
1206 will be called nsa320-hwmon.
1207
1193config SENSORS_PCF8591 1208config SENSORS_PCF8591
1194 tristate "Philips PCF8591 ADC/DAC" 1209 tristate "Philips PCF8591 ADC/DAC"
1195 depends on I2C 1210 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-$(CONFIG_SENSORS_NCT6683) += nct6683.o
124obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o 124obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o
125obj-$(CONFIG_SENSORS_NCT7802) += nct7802.o 125obj-$(CONFIG_SENSORS_NCT7802) += nct7802.o
126obj-$(CONFIG_SENSORS_NCT7904) += nct7904.o 126obj-$(CONFIG_SENSORS_NCT7904) += nct7904.o
127obj-$(CONFIG_SENSORS_NSA320) += nsa320-hwmon.o
127obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o 128obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o
128obj-$(CONFIG_SENSORS_PC87360) += pc87360.o 129obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
129obj-$(CONFIG_SENSORS_PC87427) += pc87427.o 130obj-$(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 @@
1/*
2 * drivers/hwmon/nsa320-hwmon.c
3 *
4 * ZyXEL NSA320 Media Servers
5 * hardware monitoring
6 *
7 * Copyright (C) 2016 Adam Baker <linux@baker-net.org.uk>
8 * based on a board file driver
9 * Copyright (C) 2012 Peter Schildmann <linux@schildmann.info>
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License v2 as published by the
13 * Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
18 * more details.
19 */
20
21#include <linux/bitops.h>
22#include <linux/delay.h>
23#include <linux/err.h>
24#include <linux/gpio/consumer.h>
25#include <linux/hwmon.h>
26#include <linux/hwmon-sysfs.h>
27#include <linux/jiffies.h>
28#include <linux/module.h>
29#include <linux/mutex.h>
30#include <linux/of.h>
31#include <linux/of_device.h>
32#include <linux/of_platform.h>
33#include <linux/platform_device.h>
34
35/* Tests for error return values rely upon this value being < 0x80 */
36#define MAGIC_NUMBER 0x55
37
38/*
39 * The Zyxel hwmon MCU is a Holtek HT46R065 that is factory programmed
40 * to perform temperature and fan speed monitoring. It is read by taking
41 * the active pin low. The 32 bit output word is then clocked onto the
42 * data line. The MSB of the data word is a magic nuber to indicate it
43 * has been read correctly, the next byte is the fan speed (in hundreds
44 * of RPM) and the last two bytes are the temperature (in tenths of a
45 * degree)
46 */
47
48struct nsa320_hwmon {
49 struct mutex update_lock; /* lock GPIO operations */
50 unsigned long last_updated; /* jiffies */
51 unsigned long mcu_data;
52 struct gpio_desc *act;
53 struct gpio_desc *clk;
54 struct gpio_desc *data;
55};
56
57enum nsa320_inputs {
58 NSA320_TEMP = 0,
59 NSA320_FAN = 1,
60};
61
62static const char * const nsa320_input_names[] = {
63 [NSA320_TEMP] = "System Temperature",
64 [NSA320_FAN] = "Chassis Fan",
65};
66
67/*
68 * Although this protocol looks similar to SPI the long delay
69 * between the active (aka chip select) signal and the shorter
70 * delay between clock pulses are needed for reliable operation.
71 * The delays provided are taken from the manufacturer kernel,
72 * testing suggest they probably incorporate a reasonable safety
73 * margin. (The single device tested became unreliable if the
74 * delay was reduced to 1/10th of this value.)
75 */
76static s32 nsa320_hwmon_update(struct device *dev)
77{
78 u32 mcu_data;
79 u32 mask;
80 struct nsa320_hwmon *hwmon = dev_get_drvdata(dev);
81
82 mutex_lock(&hwmon->update_lock);
83
84 mcu_data = hwmon->mcu_data;
85
86 if (time_after(jiffies, hwmon->last_updated + HZ) || mcu_data == 0) {
87 gpiod_set_value(hwmon->act, 1);
88 msleep(100);
89
90 mcu_data = 0;
91 for (mask = BIT(31); mask; mask >>= 1) {
92 gpiod_set_value(hwmon->clk, 0);
93 usleep_range(100, 200);
94 gpiod_set_value(hwmon->clk, 1);
95 usleep_range(100, 200);
96 if (gpiod_get_value(hwmon->data))
97 mcu_data |= mask;
98 }
99
100 gpiod_set_value(hwmon->act, 0);
101 dev_dbg(dev, "Read raw MCU data %08x\n", mcu_data);
102
103 if ((mcu_data >> 24) != MAGIC_NUMBER) {
104 dev_dbg(dev, "Read invalid MCU data %08x\n", mcu_data);
105 mcu_data = -EIO;
106 } else {
107 hwmon->mcu_data = mcu_data;
108 hwmon->last_updated = jiffies;
109 }
110 }
111
112 mutex_unlock(&hwmon->update_lock);
113
114 return mcu_data;
115}
116
117static ssize_t show_label(struct device *dev,
118 struct device_attribute *attr, char *buf)
119{
120 int channel = to_sensor_dev_attr(attr)->index;
121
122 return sprintf(buf, "%s\n", nsa320_input_names[channel]);
123}
124
125static ssize_t show_temp(struct device *dev, struct device_attribute *attr,
126 char *buf)
127{
128 s32 mcu_data = nsa320_hwmon_update(dev);
129
130 if (mcu_data < 0)
131 return mcu_data;
132
133 return sprintf(buf, "%d\n", (mcu_data & 0xffff) * 100);
134}
135
136static ssize_t show_fan(struct device *dev, struct device_attribute *attr,
137 char *buf)
138{
139 s32 mcu_data = nsa320_hwmon_update(dev);
140
141 if (mcu_data < 0)
142 return mcu_data;
143
144 return sprintf(buf, "%d\n", ((mcu_data & 0xff0000) >> 16) * 100);
145}
146
147static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL, NSA320_TEMP);
148static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
149static SENSOR_DEVICE_ATTR(fan1_label, S_IRUGO, show_label, NULL, NSA320_FAN);
150static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
151
152static struct attribute *nsa320_attrs[] = {
153 &sensor_dev_attr_temp1_label.dev_attr.attr,
154 &dev_attr_temp1_input.attr,
155 &sensor_dev_attr_fan1_label.dev_attr.attr,
156 &dev_attr_fan1_input.attr,
157 NULL
158};
159
160ATTRIBUTE_GROUPS(nsa320);
161
162static const struct of_device_id of_nsa320_hwmon_match[] = {
163 { .compatible = "zyxel,nsa320-mcu", },
164 { },
165};
166
167static int nsa320_hwmon_probe(struct platform_device *pdev)
168{
169 struct nsa320_hwmon *hwmon;
170 struct device *classdev;
171
172 hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
173 if (!hwmon)
174 return -ENOMEM;
175
176 /* Look up the GPIO pins to use */
177 hwmon->act = devm_gpiod_get(&pdev->dev, "act", GPIOD_OUT_LOW);
178 if (IS_ERR(hwmon->act))
179 return PTR_ERR(hwmon->act);
180
181 hwmon->clk = devm_gpiod_get(&pdev->dev, "clk", GPIOD_OUT_HIGH);
182 if (IS_ERR(hwmon->clk))
183 return PTR_ERR(hwmon->clk);
184
185 hwmon->data = devm_gpiod_get(&pdev->dev, "data", GPIOD_IN);
186 if (IS_ERR(hwmon->data))
187 return PTR_ERR(hwmon->data);
188
189 mutex_init(&hwmon->update_lock);
190
191 classdev = devm_hwmon_device_register_with_groups(&pdev->dev,
192 "nsa320", hwmon, nsa320_groups);
193
194 return PTR_ERR_OR_ZERO(classdev);
195
196}
197
198/* All allocations use devres so remove() is not needed. */
199
200static struct platform_driver nsa320_hwmon_driver = {
201 .probe = nsa320_hwmon_probe,
202 .driver = {
203 .name = "nsa320-hwmon",
204 .of_match_table = of_match_ptr(of_nsa320_hwmon_match),
205 },
206};
207
208module_platform_driver(nsa320_hwmon_driver);
209
210MODULE_DEVICE_TABLE(of, of_nsa320_hwmon_match);
211MODULE_AUTHOR("Peter Schildmann <linux@schildmann.info>");
212MODULE_AUTHOR("Adam Baker <linux@baker-net.org.uk>");
213MODULE_DESCRIPTION("NSA320 Hardware Monitoring");
214MODULE_LICENSE("GPL v2");
215MODULE_ALIAS("platform:nsa320-hwmon");
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-09 08:03:46 -0400