[PATCH v3 3/7] drivers: hwmon: Add the iEi WT61P803 PUZZLE HWMON driver
Luka Kovacic
luka.kovacic at sartura.hr
Tue Sep 29 21:40:54 EDT 2020
Add the iEi WT61P803 PUZZLE HWMON driver, that handles the fan speed
control via PWM, reading fan speed and reading on-board temperature
sensors.
The driver registers a HWMON device and a simple thermal cooling device to
enable in-kernel fan management.
This driver depends on the iEi WT61P803 PUZZLE MFD driver.
Signed-off-by: Luka Kovacic <luka.kovacic at sartura.hr>
Cc: Luka Perkov <luka.perkov at sartura.hr>
Cc: Robert Marko <robert.marko at sartura.hr>
---
drivers/hwmon/Kconfig | 8 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/iei-wt61p803-puzzle-hwmon.c | 513 ++++++++++++++++++++++
3 files changed, 522 insertions(+)
create mode 100644 drivers/hwmon/iei-wt61p803-puzzle-hwmon.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8dc28b26916e..ff279df9bf40 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -722,6 +722,14 @@ config SENSORS_IBMPOWERNV
This driver can also be built as a module. If so, the module
will be called ibmpowernv.
+config SENSORS_IEI_WT61P803_PUZZLE_HWMON
+ tristate "iEi WT61P803 PUZZLE MFD HWMON Driver"
+ depends on MFD_IEI_WT61P803_PUZZLE
+ help
+ The iEi WT61P803 PUZZLE MFD HWMON Driver handles reading fan speed
+ and writing fan PWM values. It also supports reading on-board
+ temperature sensors.
+
config SENSORS_IIO_HWMON
tristate "Hwmon driver that uses channels specified via iio maps"
depends on IIO
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index a8f4b35b136b..b0afb2d6896f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -83,6 +83,7 @@ obj-$(CONFIG_SENSORS_HIH6130) += hih6130.o
obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o
obj-$(CONFIG_SENSORS_I5500) += i5500_temp.o
obj-$(CONFIG_SENSORS_I5K_AMB) += i5k_amb.o
+obj-$(CONFIG_SENSORS_IEI_WT61P803_PUZZLE_HWMON) += iei-wt61p803-puzzle-hwmon.o
obj-$(CONFIG_SENSORS_IBMAEM) += ibmaem.o
obj-$(CONFIG_SENSORS_IBMPEX) += ibmpex.o
obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
diff --git a/drivers/hwmon/iei-wt61p803-puzzle-hwmon.c b/drivers/hwmon/iei-wt61p803-puzzle-hwmon.c
new file mode 100644
index 000000000000..990016329578
--- /dev/null
+++ b/drivers/hwmon/iei-wt61p803-puzzle-hwmon.c
@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* iEi WT61P803 PUZZLE MCU HWMON Driver
+ *
+ * Copyright (C) 2020 Sartura Ltd.
+ * Author: Luka Kovacic <luka.kovacic at sartura.hr>
+ */
+
+#include <linux/err.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/math64.h>
+#include <linux/mfd/iei-wt61p803-puzzle.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/thermal.h>
+
+#define IEI_WT61P803_PUZZLE_HWMON_MAX_TEMP_NUM 2
+#define IEI_WT61P803_PUZZLE_HWMON_MAX_FAN_NUM 5
+#define IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_NUM 2
+#define IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL 255
+
+/**
+ * struct iei_wt61p803_puzzle_thermal_cooling_device - Thermal cooling device instance
+ *
+ * @mcu_hwmon: MCU HWMON struct pointer
+ * @tcdev: Thermal cooling device pointer
+ * @name: Thermal cooling device name
+ * @pwm_channel: PWM channel (0 or 1)
+ * @cooling_levels: Thermal cooling device cooling levels
+ */
+struct iei_wt61p803_puzzle_thermal_cooling_device {
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon;
+ struct thermal_cooling_device *tcdev;
+ char name[THERMAL_NAME_LENGTH];
+ int pwm_channel;
+ u8 *cooling_levels;
+};
+
+/**
+ * struct iei_wt61p803_puzzle_hwmon - MCU HWMON Driver
+ *
+ * @mcu: MCU struct pointer
+ * @lock General member lock
+ * @response_buffer Global MCU response buffer allocation
+ * @temp_sensor_val: Temperature sensor values
+ * @fan_speed_val: FAN speed (RPM) values
+ * @pwm_val: PWM values (0-255)
+ * @thermal_cooling_dev_present: Per-channel thermal cooling device control
+ * @cdev: Per-channel thermal cooling device private structure
+ */
+struct iei_wt61p803_puzzle_hwmon {
+ struct iei_wt61p803_puzzle *mcu;
+ struct mutex lock;
+ unsigned char *response_buffer;
+ int temp_sensor_val[IEI_WT61P803_PUZZLE_HWMON_MAX_TEMP_NUM];
+ int fan_speed_val[IEI_WT61P803_PUZZLE_HWMON_MAX_FAN_NUM];
+ int pwm_val[IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_NUM];
+ bool thermal_cooling_dev_present[IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_NUM];
+ struct iei_wt61p803_puzzle_thermal_cooling_device
+ *cdev[IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_NUM];
+};
+
+#define raw_temp_to_milidegree_celsius(x) ((int)((x - 0x80)*1000))
+static int iei_wt61p803_puzzle_read_temp_sensor
+(struct iei_wt61p803_puzzle_hwmon *mcu_hwmon, int channel, int *value)
+{
+ unsigned char *resp_buf = mcu_hwmon->response_buffer;
+ unsigned char temp_sensor_ntc_cmd[4] = {
+ IEI_WT61P803_PUZZLE_CMD_HEADER_START,
+ IEI_WT61P803_PUZZLE_CMD_TEMP,
+ IEI_WT61P803_PUZZLE_CMD_TEMP_ALL
+ };
+ size_t reply_size = 0;
+ int ret;
+
+ if (channel > 1 && channel < 0)
+ return -EINVAL;
+
+ mutex_lock(&mcu_hwmon->lock);
+ ret = iei_wt61p803_puzzle_write_command(mcu_hwmon->mcu,
+ temp_sensor_ntc_cmd, sizeof(temp_sensor_ntc_cmd),
+ resp_buf, &reply_size);
+ if (!ret) {
+ /* Check the number of NTC values (should be 0x32/'2') */
+ if (resp_buf[3] == 0x32) {
+ /* Write values to the struct */
+ mcu_hwmon->temp_sensor_val[0] =
+ raw_temp_to_milidegree_celsius(resp_buf[4]);
+ mcu_hwmon->temp_sensor_val[1] =
+ raw_temp_to_milidegree_celsius(resp_buf[5]);
+ }
+
+ }
+ *value = mcu_hwmon->temp_sensor_val[channel];
+ mutex_unlock(&mcu_hwmon->lock);
+
+ return ret;
+}
+
+#define raw_fan_val_to_rpm(x, y) ((int)(((x)<<8|(y))/2)*60)
+static int iei_wt61p803_puzzle_read_fan_speed
+(struct iei_wt61p803_puzzle_hwmon *mcu_hwmon, int channel, int *value)
+{
+ unsigned char *resp_buf = mcu_hwmon->response_buffer;
+ unsigned char fan_speed_cmd[4] = {
+ IEI_WT61P803_PUZZLE_CMD_HEADER_START,
+ IEI_WT61P803_PUZZLE_CMD_FAN,
+ IEI_WT61P803_PUZZLE_CMD_FAN_RPM_0
+ };
+ size_t reply_size = 0;
+ int ret;
+
+ switch (channel) {
+ case 0:
+ fan_speed_cmd[2] = IEI_WT61P803_PUZZLE_CMD_FAN_RPM_0;
+ break;
+ case 1:
+ fan_speed_cmd[2] = IEI_WT61P803_PUZZLE_CMD_FAN_RPM_1;
+ break;
+ case 2:
+ fan_speed_cmd[2] = IEI_WT61P803_PUZZLE_CMD_FAN_RPM_2;
+ break;
+ case 3:
+ fan_speed_cmd[2] = IEI_WT61P803_PUZZLE_CMD_FAN_RPM_3;
+ break;
+ case 4:
+ fan_speed_cmd[2] = IEI_WT61P803_PUZZLE_CMD_FAN_RPM_4;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mutex_lock(&mcu_hwmon->lock);
+ ret = iei_wt61p803_puzzle_write_command(mcu_hwmon->mcu, fan_speed_cmd,
+ sizeof(fan_speed_cmd), resp_buf, &reply_size);
+ if (!ret)
+ mcu_hwmon->fan_speed_val[channel] = raw_fan_val_to_rpm(resp_buf[3],
+ resp_buf[4]);
+
+ *value = mcu_hwmon->fan_speed_val[channel];
+ mutex_unlock(&mcu_hwmon->lock);
+
+ return 0;
+}
+
+static int iei_wt61p803_puzzle_write_pwm_channel
+(struct iei_wt61p803_puzzle_hwmon *mcu_hwmon, int channel, long pwm_set_val)
+{
+ unsigned char *resp_buf = mcu_hwmon->response_buffer;
+ unsigned char pwm_set_cmd[6] = {
+ IEI_WT61P803_PUZZLE_CMD_HEADER_START,
+ IEI_WT61P803_PUZZLE_CMD_FAN,
+ IEI_WT61P803_PUZZLE_CMD_FAN_PWM_WRITE,
+ IEI_WT61P803_PUZZLE_CMD_FAN_PWM_0,
+ 0x00
+ };
+ size_t reply_size = 0;
+ int ret;
+
+ switch (channel) {
+ case 0:
+ pwm_set_cmd[3] = IEI_WT61P803_PUZZLE_CMD_FAN_PWM_0;
+ break;
+ case 1:
+ pwm_set_cmd[3] = IEI_WT61P803_PUZZLE_CMD_FAN_PWM_1;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (pwm_set_val < 0 || pwm_set_val > IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL)
+ return -EINVAL;
+
+ /* Add the PWM value to the command */
+ pwm_set_cmd[4] = (char)pwm_set_val;
+
+ mutex_lock(&mcu_hwmon->lock);
+ ret = iei_wt61p803_puzzle_write_command(mcu_hwmon->mcu, pwm_set_cmd,
+ sizeof(pwm_set_cmd), resp_buf, &reply_size);
+ if (!ret) {
+ /* Store the PWM value */
+ if (resp_buf[0] == IEI_WT61P803_PUZZLE_CMD_HEADER_START &&
+ resp_buf[1] == IEI_WT61P803_PUZZLE_CMD_RESPONSE_OK &&
+ resp_buf[2] == IEI_WT61P803_PUZZLE_CHECKSUM_RESPONSE_OK)
+ mcu_hwmon->pwm_val[channel] = (int)pwm_set_val;
+ }
+ mutex_unlock(&mcu_hwmon->lock);
+
+ return 0;
+}
+
+static int iei_wt61p803_puzzle_read_pwm_channel
+(struct iei_wt61p803_puzzle_hwmon *mcu_hwmon, int channel, int *value)
+{
+ unsigned char *resp_buf = mcu_hwmon->response_buffer;
+ unsigned char pwm_get_cmd[5] = {
+ IEI_WT61P803_PUZZLE_CMD_HEADER_START,
+ IEI_WT61P803_PUZZLE_CMD_FAN,
+ IEI_WT61P803_PUZZLE_CMD_FAN_PWM_READ,
+ IEI_WT61P803_PUZZLE_CMD_FAN_PWM_0
+ };
+ size_t reply_size = 0;
+ int ret;
+
+ switch (channel) {
+ case 0:
+ pwm_get_cmd[3] = IEI_WT61P803_PUZZLE_CMD_FAN_PWM_0;
+ break;
+ case 1:
+ pwm_get_cmd[3] = IEI_WT61P803_PUZZLE_CMD_FAN_PWM_1;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ mutex_lock(&mcu_hwmon->lock);
+ ret = iei_wt61p803_puzzle_write_command(mcu_hwmon->mcu, pwm_get_cmd,
+ sizeof(pwm_get_cmd), resp_buf, &reply_size);
+ if (!ret) {
+ /* Store the PWM value */
+ if (resp_buf[2] == IEI_WT61P803_PUZZLE_CMD_FAN_PWM_READ)
+ mcu_hwmon->pwm_val[channel] = (int)resp_buf[3];
+ }
+ *value = mcu_hwmon->pwm_val[channel];
+ mutex_unlock(&mcu_hwmon->lock);
+
+ return 0;
+}
+
+static int iei_wt61p803_puzzle_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon =
+ dev_get_drvdata(dev->parent);
+ int ret, value;
+
+ switch (type) {
+ case hwmon_pwm:
+ if (attr != hwmon_pwm_input)
+ return -ENODEV;
+ ret = iei_wt61p803_puzzle_read_pwm_channel(mcu_hwmon, channel, &value);
+ if (ret)
+ return ret;
+ *val = (long)value;
+ return ret;
+ case hwmon_fan:
+ if (attr != hwmon_fan_input)
+ return -ENODEV;
+ ret = iei_wt61p803_puzzle_read_fan_speed(mcu_hwmon, channel, &value);
+ if (ret)
+ return ret;
+ *val = (long)value;
+ return ret;
+ case hwmon_temp:
+ if (attr != hwmon_temp_input)
+ return -ENODEV;
+ ret = iei_wt61p803_puzzle_read_temp_sensor(mcu_hwmon, channel, &value);
+ if (ret)
+ return ret;
+ *val = (long)value;
+ return ret;
+ default:
+ return -ENODEV;
+ }
+}
+
+static int iei_wt61p803_puzzle_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon =
+ dev_get_drvdata(dev->parent);
+
+ switch (type) {
+ case hwmon_pwm:
+ if (attr != hwmon_pwm_input)
+ return -ENODEV;
+ if (mcu_hwmon->thermal_cooling_dev_present[channel]) {
+ /*
+ * The Thermal Framework has already claimed this specific PWM
+ * channel.
+ */
+ return -EBUSY;
+ }
+ return iei_wt61p803_puzzle_write_pwm_channel(mcu_hwmon, channel, val);
+ default:
+ return -ENODEV;
+ }
+}
+
+static umode_t iei_wt61p803_puzzle_is_visible(const void *data,
+ enum hwmon_sensor_types type, u32 attr, int channel)
+{
+ const struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = data;
+
+ switch (type) {
+ case hwmon_pwm:
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (mcu_hwmon->thermal_cooling_dev_present[channel])
+ return 0444;
+ return 0644;
+ default:
+ return 0;
+ }
+ case hwmon_fan:
+ switch (attr) {
+ case hwmon_fan_input:
+ return 0444;
+ default:
+ return 0;
+ }
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ return 0444;
+ default:
+ return 0;
+ }
+ default:
+ return 0;
+ }
+}
+
+static const struct hwmon_ops iei_wt61p803_puzzle_hwmon_ops = {
+ .is_visible = iei_wt61p803_puzzle_is_visible,
+ .read = iei_wt61p803_puzzle_read,
+ .write = iei_wt61p803_puzzle_write,
+};
+
+static const struct hwmon_channel_info *iei_wt61p803_puzzle_info[] = {
+ HWMON_CHANNEL_INFO(pwm,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT),
+ HWMON_CHANNEL_INFO(fan,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT),
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_chip_info iei_wt61p803_puzzle_chip_info = {
+ .ops = &iei_wt61p803_puzzle_hwmon_ops,
+ .info = iei_wt61p803_puzzle_info,
+};
+
+static int iei_wt61p803_puzzle_get_max_state
+(struct thermal_cooling_device *tcdev, unsigned long *state)
+{
+ *state = IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL;
+
+ return 0;
+}
+static int iei_wt61p803_puzzle_get_cur_state
+(struct thermal_cooling_device *tcdev, unsigned long *state)
+{
+ struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
+
+ int ret, value;
+
+ if (!mcu_hwmon)
+ return -EINVAL;
+
+ ret = iei_wt61p803_puzzle_read_pwm_channel(mcu_hwmon,
+ cdev->pwm_channel, &value);
+ if (ret)
+ return ret;
+
+ *state = (unsigned long)value;
+
+ return 0;
+}
+static int iei_wt61p803_puzzle_set_cur_state
+(struct thermal_cooling_device *tcdev, unsigned long state)
+{
+ struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
+
+ if (!mcu_hwmon)
+ return -EINVAL;
+
+ return iei_wt61p803_puzzle_write_pwm_channel(mcu_hwmon,
+ cdev->pwm_channel, state);
+}
+static const struct thermal_cooling_device_ops iei_wt61p803_puzzle_cooling_ops = {
+ .get_max_state = iei_wt61p803_puzzle_get_max_state,
+ .get_cur_state = iei_wt61p803_puzzle_get_cur_state,
+ .set_cur_state = iei_wt61p803_puzzle_set_cur_state,
+};
+
+static int iei_wt61p803_puzzle_enable_thermal_cooling_dev
+(struct device *dev, struct fwnode_handle *child, struct iei_wt61p803_puzzle_hwmon *mcu_hwmon)
+{
+ struct iei_wt61p803_puzzle_thermal_cooling_device *cdev;
+ int ret, num_levels;
+ u32 pwm_channel;
+
+ ret = fwnode_property_read_u32(child, "reg", &pwm_channel);
+ if (ret)
+ return ret;
+
+ mutex_lock(&mcu_hwmon->lock);
+ mcu_hwmon->thermal_cooling_dev_present[pwm_channel] = true;
+ mutex_unlock(&mcu_hwmon->lock);
+
+ num_levels = fwnode_property_read_u8_array(child, "cooling-levels", NULL, 0);
+ if (num_levels > 0) {
+ cdev = devm_kzalloc(dev, sizeof(*cdev), GFP_KERNEL);
+ if (!cdev)
+ return -ENOMEM;
+
+ cdev->cooling_levels = devm_kzalloc(dev, num_levels, GFP_KERNEL);
+ if (!cdev->cooling_levels)
+ return -ENOMEM;
+
+ ret = fwnode_property_read_u8_array(child, "cooling-levels",
+ cdev->cooling_levels, num_levels);
+ if (ret) {
+ dev_err(dev, "Couldn't read property 'cooling-levels'");
+ return ret;
+ }
+
+ snprintf(cdev->name, THERMAL_NAME_LENGTH, "iei_wt61p803_puzzle_%d", pwm_channel);
+
+ cdev->tcdev = devm_thermal_of_cooling_device_register(dev, NULL,
+ cdev->name, cdev, &iei_wt61p803_puzzle_cooling_ops);
+ if (IS_ERR(cdev->tcdev))
+ return PTR_ERR(cdev->tcdev);
+
+ cdev->mcu_hwmon = mcu_hwmon;
+ cdev->pwm_channel = pwm_channel;
+
+ mutex_lock(&mcu_hwmon->lock);
+ mcu_hwmon->cdev[pwm_channel] = cdev;
+ mutex_unlock(&mcu_hwmon->lock);
+ }
+ return 0;
+}
+
+static int iei_wt61p803_puzzle_hwmon_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iei_wt61p803_puzzle *mcu = dev_get_drvdata(dev->parent);
+ struct iei_wt61p803_puzzle_hwmon *mcu_hwmon;
+ struct fwnode_handle *child;
+ struct device *hwmon_dev;
+ int ret;
+
+ mcu_hwmon = devm_kzalloc(dev, sizeof(*mcu_hwmon), GFP_KERNEL);
+ if (!mcu_hwmon)
+ return -ENOMEM;
+
+ mcu_hwmon->response_buffer = devm_kzalloc(dev,
+ IEI_WT61P803_PUZZLE_BUF_SIZE, GFP_KERNEL);
+ if (!mcu_hwmon->response_buffer)
+ return -ENOMEM;
+
+ mcu_hwmon->mcu = mcu;
+ mutex_init(&mcu_hwmon->lock);
+ platform_set_drvdata(pdev, mcu_hwmon);
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev,
+ "iei_wt61p803_puzzle",
+ mcu_hwmon,
+ &iei_wt61p803_puzzle_chip_info,
+ NULL);
+
+ if (IS_ERR(hwmon_dev))
+ return PTR_ERR(hwmon_dev);
+
+ /* Control fans via PWM lines via Linux Kernel */
+ if (IS_ENABLED(CONFIG_THERMAL)) {
+ device_for_each_child_node(dev, child) {
+ ret = iei_wt61p803_puzzle_enable_thermal_cooling_dev(dev, child, mcu_hwmon);
+ if (ret) {
+ dev_err(dev, "Enabling the PWM fan failed\n");
+ fwnode_handle_put(child);
+ return ret;
+ }
+ }
+ }
+ return 0;
+}
+
+static const struct of_device_id iei_wt61p803_puzzle_hwmon_id_table[] = {
+ { .compatible = "iei,wt61p803-puzzle-hwmon" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, iei_wt61p803_puzzle_hwmon_id_table);
+
+static struct platform_driver iei_wt61p803_puzzle_hwmon_driver = {
+ .driver = {
+ .name = "iei-wt61p803-puzzle-hwmon",
+ .of_match_table = iei_wt61p803_puzzle_hwmon_id_table,
+ },
+ .probe = iei_wt61p803_puzzle_hwmon_probe,
+};
+
+module_platform_driver(iei_wt61p803_puzzle_hwmon_driver);
+
+MODULE_DESCRIPTION("iEi WT61P803 PUZZLE MCU HWMON Driver");
+MODULE_AUTHOR("Luka Kovacic <luka.kovacic at sartura.hr>");
+MODULE_LICENSE("GPL");
--
2.26.2
More information about the linux-arm-kernel
mailing list