On 24/04/2024 19:38:03+0200, Marek Behún wrote:
> Add support for true board poweroff (MCU can disable all unnecessary
> voltage regulators) and wakeup at a specified time, implemented via a
> RTC driver so that the rtcwake utility can be used to configure it.
>
> Signed-off-by: Marek Behún <kabel@xxxxxxxxxx>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
> .../sysfs-bus-i2c-devices-turris-omnia-mcu | 16 ++
> drivers/platform/cznic/Kconfig | 4 +
> drivers/platform/cznic/Makefile | 1 +
> .../platform/cznic/turris-omnia-mcu-base.c | 5 +
> .../cznic/turris-omnia-mcu-sys-off-wakeup.c | 258 ++++++++++++++++++
> drivers/platform/cznic/turris-omnia-mcu.h | 20 ++
> 6 files changed, 304 insertions(+)
> create mode 100644 drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu b/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
> index b27b60d00c87..564119849388 100644
> --- a/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
> +++ b/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
> @@ -38,6 +38,22 @@ Description: (RW) The front button on the Turris Omnia router can be
>
> Format: %s.
>
> +What: /sys/bus/i2c/devices/<mcu_device>/front_button_poweron
> +Date: July 2024
> +KernelVersion: 6.10
> +Contact: Marek Behún <kabel@xxxxxxxxxx>
> +Description: (RW) Newer versions of the microcontroller firmware of the
> + Turris Omnia router support powering off the router into true
> + low power mode. The router can be powered on by pressing the
> + front button.
> +
> + This file configures whether front button power on is enabled.
> +
> + This file is present only if the power off feature is supported
> + by the firmware.
> +
> + Format: %i.
> +
> What: /sys/bus/i2c/devices/<mcu_device>/fw_features
> Date: July 2024
> KernelVersion: 6.10
> diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
> index 3a8c3edcd7e6..0a752aa654fa 100644
> --- a/drivers/platform/cznic/Kconfig
> +++ b/drivers/platform/cznic/Kconfig
> @@ -19,10 +19,14 @@ config TURRIS_OMNIA_MCU
> depends on I2C
> select GPIOLIB
> select GPIOLIB_IRQCHIP
> + select RTC_CLASS
> help
> Say Y here to add support for the features implemented by the
> microcontroller on the CZ.NIC's Turris Omnia SOHO router.
> The features include:
> + - board poweroff into true low power mode (with voltage regulators
> + disabled) and the ability to configure wake up from this mode (via
> + rtcwake)
> - GPIO pins
> - to get front button press events (the front button can be
> configured either to generate press events to the CPU or to change
> diff --git a/drivers/platform/cznic/Makefile b/drivers/platform/cznic/Makefile
> index 53fd8f1777a3..a185ef882e44 100644
> --- a/drivers/platform/cznic/Makefile
> +++ b/drivers/platform/cznic/Makefile
> @@ -3,3 +3,4 @@
> obj-$(CONFIG_TURRIS_OMNIA_MCU) += turris-omnia-mcu.o
> turris-omnia-mcu-y := turris-omnia-mcu-base.o
> turris-omnia-mcu-y += turris-omnia-mcu-gpio.o
> +turris-omnia-mcu-y += turris-omnia-mcu-sys-off-wakeup.o
> diff --git a/drivers/platform/cznic/turris-omnia-mcu-base.c b/drivers/platform/cznic/turris-omnia-mcu-base.c
> index 708b084cb5da..697ace090bda 100644
> --- a/drivers/platform/cznic/turris-omnia-mcu-base.c
> +++ b/drivers/platform/cznic/turris-omnia-mcu-base.c
> @@ -195,6 +195,7 @@ static const struct attribute_group omnia_mcu_base_group = {
> static const struct attribute_group *omnia_mcu_groups[] = {
> &omnia_mcu_base_group,
> &omnia_mcu_gpio_group,
> + &omnia_mcu_poweroff_group,
> NULL
> };
>
> @@ -360,6 +361,10 @@ static int omnia_mcu_probe(struct i2c_client *client)
> "Cannot read board info\n");
> }
>
> + err = omnia_mcu_register_sys_off_and_wakeup(mcu);
> + if (err)
> + return err;
> +
> return omnia_mcu_register_gpiochip(mcu);
> }
>
> diff --git a/drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c b/drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
> new file mode 100644
> index 000000000000..fbd1b4cd7011
> --- /dev/null
> +++ b/drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * CZ.NIC's Turris Omnia MCU system off and RTC wakeup driver
> + *
> + * This is not a true RTC driver (in the sense that it does not provide a
> + * real-time clock), rather the MCU implements a wakeup from powered off state
> + * at a specified time relative to MCU boot, and we expose this feature via RTC
> + * alarm, so that it can be used via the rtcwake command, which is the standard
> + * Linux command for this.
> + *
> + * 2024 by Marek Behún <kabel@xxxxxxxxxx>
> + */
> +
> +#include <linux/crc32.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/reboot.h>
> +#include <linux/rtc.h>
> +#include <linux/sysfs.h>
> +#include <linux/turris-omnia-mcu-interface.h>
> +#include <linux/types.h>
> +
> +#include "turris-omnia-mcu.h"
> +
> +static int omnia_get_uptime_wakeup(const struct i2c_client *client, u32 *uptime,
> + u32 *wakeup)
> +{
> + __le32 reply[2];
> + int err;
> +
> + err = omnia_cmd_read(client, CMD_GET_UPTIME_AND_WAKEUP, reply,
> + sizeof(reply));
> + if (err)
> + return err;
> +
> + if (uptime)
> + *uptime = le32_to_cpu(reply[0]);
> +
> + if (wakeup)
> + *wakeup = le32_to_cpu(reply[1]);
> +
> + return 0;
> +}
> +
> +static int omnia_read_time(struct device *dev, struct rtc_time *tm)
> +{
> + u32 uptime;
> + int err;
> +
> + err = omnia_get_uptime_wakeup(to_i2c_client(dev), &uptime, NULL);
> + if (err)
> + return err;
> +
> + rtc_time64_to_tm(uptime, tm);
> +
> + return 0;
> +}
> +
> +static int omnia_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct omnia_mcu *mcu = i2c_get_clientdata(client);
> + u32 wakeup;
> + int err;
> +
> + err = omnia_get_uptime_wakeup(client, NULL, &wakeup);
> + if (err)
> + return err;
> +
> + alrm->enabled = !!wakeup;
> + rtc_time64_to_tm(wakeup ?: mcu->rtc_alarm, &alrm->time);
> +
> + return 0;
> +}
> +
> +static int omnia_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct omnia_mcu *mcu = i2c_get_clientdata(client);
> +
> + mcu->rtc_alarm = rtc_tm_to_time64(&alrm->time);
> +
> + if (alrm->enabled)
> + return omnia_cmd_write_u32(client, CMD_SET_WAKEUP,
> + mcu->rtc_alarm);
> +
> + return 0;
> +}
> +
> +static int omnia_alarm_irq_enable(struct device *dev, unsigned int enabled)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct omnia_mcu *mcu = i2c_get_clientdata(client);
> +
> + return omnia_cmd_write_u32(client, CMD_SET_WAKEUP,
> + enabled ? mcu->rtc_alarm : 0);
> +}
> +
> +static const struct rtc_class_ops omnia_rtc_ops = {
> + .read_time = omnia_read_time,
> + .read_alarm = omnia_read_alarm,
> + .set_alarm = omnia_set_alarm,
> + .alarm_irq_enable = omnia_alarm_irq_enable,
> +};
> +
> +static int omnia_power_off(struct sys_off_data *data)
> +{
> + struct omnia_mcu *mcu = data->cb_data;
> + __be32 tmp;
> + u8 cmd[9];
> + u16 arg;
> + int err;
> +
> + if (mcu->front_button_poweron)
> + arg = CMD_POWER_OFF_POWERON_BUTTON;
> + else
> + arg = 0;
> +
> + cmd[0] = CMD_POWER_OFF;
> + put_unaligned_le16(CMD_POWER_OFF_MAGIC, &cmd[1]);
> + put_unaligned_le16(arg, &cmd[3]);
> +
> + /*
> + * Although all values from and to MCU are passed in little-endian, the
> + * MCU's CRC unit uses big-endian CRC32 polynomial (0x04c11db7), so we
> + * need to use crc32_be() here.
> + */
> + tmp = cpu_to_be32(get_unaligned_le32(&cmd[1]));
> + put_unaligned_le32(crc32_be(0xffffffff, (void *)&tmp, sizeof(tmp)),
> + &cmd[5]);
> +
> + err = omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
> + if (err)
> + dev_err(&mcu->client->dev,
> + "Unable to send the poweroff command: %d\n", err);
> +
> + return NOTIFY_DONE;
> +}
> +
> +static int omnia_restart(struct sys_off_data *data)
> +{
> + struct omnia_mcu *mcu = data->cb_data;
> + u8 cmd[3];
> + int err;
> +
> + cmd[0] = CMD_GENERAL_CONTROL;
> +
> + if (reboot_mode == REBOOT_HARD)
> + cmd[1] = cmd[2] = CTL_HARD_RST;
> + else
> + cmd[1] = cmd[2] = CTL_LIGHT_RST;
> +
> + err = omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
> + if (err)
> + dev_err(&mcu->client->dev,
> + "Unable to send the restart command: %d\n", err);
> +
> + /*
> + * MCU needs a little bit to process the I2C command, otherwise it will
> + * do a light reset based on SOC SYSRES_OUT pin.
> + */
> + mdelay(1);
> +
> + return NOTIFY_DONE;
> +}
> +
> +static ssize_t front_button_poweron_show(struct device *dev,
> + struct device_attribute *a, char *buf)
> +{
> + struct omnia_mcu *mcu = dev_get_drvdata(dev);
> +
> + return sysfs_emit(buf, "%d\n", mcu->front_button_poweron);
> +}
> +
> +static ssize_t front_button_poweron_store(struct device *dev,
> + struct device_attribute *a,
> + const char *buf, size_t count)
> +{
> + struct omnia_mcu *mcu = dev_get_drvdata(dev);
> + bool val;
> + int err;
> +
> + err = kstrtobool(buf, &val);
> + if (err)
> + return err;
> +
> + mcu->front_button_poweron = val;
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(front_button_poweron);
> +
> +static struct attribute *omnia_mcu_poweroff_attrs[] = {
> + &dev_attr_front_button_poweron.attr,
> + NULL
> +};
> +
> +static umode_t poweroff_attrs_visible(struct kobject *kobj, struct attribute *a,
> + int n)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct omnia_mcu *mcu = dev_get_drvdata(dev);
> +
> + if (mcu->features & FEAT_POWEROFF_WAKEUP)
> + return a->mode;
> +
> + return 0;
> +}
> +
> +const struct attribute_group omnia_mcu_poweroff_group = {
> + .attrs = omnia_mcu_poweroff_attrs,
> + .is_visible = poweroff_attrs_visible,
> +};
> +
> +int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu)
> +{
> + struct device *dev = &mcu->client->dev;
> + int err;
> +
> + /* MCU restart is always available */
> + err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART,
> + SYS_OFF_PRIO_FIRMWARE,
> + omnia_restart, mcu);
> + if (err)
> + return dev_err_probe(dev, err,
> + "Cannot register system restart handler\n");
> +
> + /*
> + * Poweroff and wakeup are available only if POWEROFF_WAKEUP feature is
> + * present.
> + */
> + if (!(mcu->features & FEAT_POWEROFF_WAKEUP))
> + return 0;
> +
> + err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_POWER_OFF,
> + SYS_OFF_PRIO_FIRMWARE,
> + omnia_power_off, mcu);
> + if (err)
> + return dev_err_probe(dev, err,
> + "Cannot register system power off handler\n");
> +
> + mcu->rtcdev = devm_rtc_allocate_device(dev);
> + if (IS_ERR(mcu->rtcdev))
> + return dev_err_probe(dev, PTR_ERR(mcu->rtcdev),
> + "Cannot allocate RTC device\n");
> +
> + mcu->rtcdev->ops = &omnia_rtc_ops;
> + mcu->rtcdev->range_max = U32_MAX;
> + set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, mcu->rtcdev->features);
> +
> + err = devm_rtc_register_device(mcu->rtcdev);
> + if (err)
> + return dev_err_probe(dev, err, "Cannot register RTC device\n");
> +
> + mcu->front_button_poweron = true;
> +
> + return 0;
> +}
> diff --git a/drivers/platform/cznic/turris-omnia-mcu.h b/drivers/platform/cznic/turris-omnia-mcu.h
> index e8d9bf1c8fdc..6179a4f2069e 100644
> --- a/drivers/platform/cznic/turris-omnia-mcu.h
> +++ b/drivers/platform/cznic/turris-omnia-mcu.h
> @@ -12,9 +12,11 @@
> #include <linux/gpio/driver.h>
> #include <linux/if_ether.h>
> #include <linux/mutex.h>
> +#include <linux/rtc.h>
> #include <linux/types.h>
> #include <linux/workqueue.h>
> #include <asm/byteorder.h>
> +#include <asm/unaligned.h>
>
> struct omnia_mcu {
> struct i2c_client *client;
> @@ -34,6 +36,11 @@ struct omnia_mcu {
> struct delayed_work button_release_emul_work;
> u16 last_status;
> bool button_pressed_emul;
> +
> + /* RTC device for configuring wake-up */
> + struct rtc_device *rtcdev;
> + u32 rtc_alarm;
> + bool front_button_poweron;
> };
>
> int omnia_cmd_write_read(const struct i2c_client *client,
> @@ -46,6 +53,17 @@ static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd,
> return omnia_cmd_write_read(client, cmd, len, NULL, 0);
> }
>
> +static inline int omnia_cmd_write_u32(const struct i2c_client *client, u8 cmd,
> + u32 val)
> +{
> + u8 buf[5];
> +
> + buf[0] = cmd;
> + put_unaligned_le32(val, &buf[1]);
> +
> + return omnia_cmd_write(client, buf, sizeof(buf));
> +}
> +
> static inline int omnia_cmd_read(const struct i2c_client *client, u8 cmd,
> void *reply, unsigned int len)
> {
> @@ -107,7 +125,9 @@ static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
> }
>
> extern const struct attribute_group omnia_mcu_gpio_group;
> +extern const struct attribute_group omnia_mcu_poweroff_group;
>
> int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu);
> +int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu);
>
> #endif /* __TURRIS_OMNIA_MCU_H */
> --
> 2.43.2
>
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
