[PATCH v12 0/8] Turris Omnia MCU driver

[PATCH v12 0/8] Turris Omnia MCU driver

[Marek Behún]

Hello Andy, Hans, Ilpo, Arnd, Gregory, and others,

this is v12 of the series adding Turris Omnia MCU driver.

Changes since v11:
- fixed some includes, suggested by Andy
- moved #include <linux/turris-omnia-mcu-interface.h> after the other
  includes, since it is domain specific, suggested by Andy
- in patch 2, use sizeof() of dest buffer in memcpy call, instead of
  ETH_ALEN constant, as suggested by Andy
- in patch 3, dropped the .has_int member of omnia GPIO definition
  structure, and added is_int_bit_valid() function instead, as suggested
  by Andy
- in patch 3, changed int to unsigned int where appropriate, as
  suggested by Andy
- in patch 3, fixed docstring indentation, suggested by Andy
- in patch 4 dropped #include <linux/rtc.h>, and instead declared struct
  rtc_device, it is only used as a pointer, suggested by Andy
- in patch 5, renamed the completion from trng_completion to
  trng_entropy_available
- in patch 5, use gpio_device_get_desc() instead of gpiochip_get_desc()
  when mapping IRQ (as discussed with Andy and Bart)
- in patch 5, dropped setting the priv member of hwrng, and instead use
  container_of() to get the driver private structure, suggested by
  Herbert

Links to previous cover letters (v1 to v11):
  https://patchwork.kernel.org/project/linux-soc/cover/20230823161012.6986-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20230919103815.16818-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20231023143130.11602-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20231026161803.16750-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240323164359.21642-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240418121116.22184-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240424173809.7214-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240430115111.3453-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240508103118.23345-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240510101819.13551-1-kabel@kernel.org/
  https://patchwork.kernel.org/project/linux-soc/cover/20240605161851.13911-1-kabel@kernel.org/

Marek Behún (8):
  dt-bindings: firmware: add cznic,turris-omnia-mcu binding
  platform: cznic: Add preliminary support for Turris Omnia MCU
  platform: cznic: turris-omnia-mcu: Add support for MCU connected GPIOs
  platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup
  platform: cznic: turris-omnia-mcu: Add support for MCU watchdog
  platform: cznic: turris-omnia-mcu: Add support for MCU provided TRNG
  ARM: dts: turris-omnia: Add MCU system-controller node
  ARM: dts: turris-omnia: Add GPIO key node for front button

 .../sysfs-bus-i2c-devices-turris-omnia-mcu    |  113 ++
 .../firmware/cznic,turris-omnia-mcu.yaml      |   86 ++
 MAINTAINERS                                   |    4 +
 .../dts/marvell/armada-385-turris-omnia.dts   |   35 +-
 drivers/platform/Kconfig                      |    2 +
 drivers/platform/Makefile                     |    1 +
 drivers/platform/cznic/Kconfig                |   48 +
 drivers/platform/cznic/Makefile               |    8 +
 .../platform/cznic/turris-omnia-mcu-base.c    |  408 +++++++
 .../platform/cznic/turris-omnia-mcu-gpio.c    | 1088 +++++++++++++++++
 .../cznic/turris-omnia-mcu-sys-off-wakeup.c   |  260 ++++
 .../platform/cznic/turris-omnia-mcu-trng.c    |  103 ++
 .../cznic/turris-omnia-mcu-watchdog.c         |  130 ++
 drivers/platform/cznic/turris-omnia-mcu.h     |  194 +++
 include/linux/turris-omnia-mcu-interface.h    |  249 ++++
 15 files changed, 2728 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
 create mode 100644 Documentation/devicetree/bindings/firmware/cznic,turris-omnia-mcu.yaml
 create mode 100644 drivers/platform/cznic/Kconfig
 create mode 100644 drivers/platform/cznic/Makefile
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-base.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-gpio.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-trng.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-watchdog.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu.h
 create mode 100644 include/linux/turris-omnia-mcu-interface.h

-- 
2.44.2

[PATCH v12 2/8] platform: cznic: Add preliminary support for Turris Omnia MCU

[Marek Behún]

Add the basic skeleton for a new platform driver for the microcontroller
found on the Turris Omnia board.

Signed-off-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
---
 .../sysfs-bus-i2c-devices-turris-omnia-mcu    |  81 ++++
 MAINTAINERS                                   |   3 +
 drivers/platform/Kconfig                      |   2 +
 drivers/platform/Makefile                     |   1 +
 drivers/platform/cznic/Kconfig                |  25 ++
 drivers/platform/cznic/Makefile               |   4 +
 .../platform/cznic/turris-omnia-mcu-base.c    | 394 ++++++++++++++++++
 drivers/platform/cznic/turris-omnia-mcu.h     |  74 ++++
 include/linux/turris-omnia-mcu-interface.h    | 249 +++++++++++
 9 files changed, 833 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
 create mode 100644 drivers/platform/cznic/Kconfig
 create mode 100644 drivers/platform/cznic/Makefile
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu-base.c
 create mode 100644 drivers/platform/cznic/turris-omnia-mcu.h
 create mode 100644 include/linux/turris-omnia-mcu-interface.h

diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu b/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
new file mode 100644
index 000000000000..9bc5aad00de0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
@@ -0,0 +1,81 @@
+What:		/sys/bus/i2c/devices/<mcu_device>/board_revision
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains board revision number.
+
+		Only available if board information is burned in the MCU (older
+		revisions have board information burned in the ATSHA204-A chip).
+
+		Format: %u.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/first_mac_address
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains device first MAC address. Each Turris Omnia is
+		allocated 3 MAC addresses. The two additional addresses are
+		computed from the first one by incrementing it.
+
+		Only available if board information is burned in the MCU (older
+		revisions have board information burned in the ATSHA204-A chip).
+
+		Format: %pM.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_features
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Newer versions of the microcontroller firmware report the
+		features they support. These can be read from this file. If the
+		MCU firmware is too old, this file reads 0x0.
+
+		Format: 0x%x.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_version_hash_application
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains the version hash (commit hash) of the application
+		part of the microcontroller firmware.
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_version_hash_bootloader
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains the version hash (commit hash) of the bootloader
+		part of the microcontroller firmware.
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/mcu_type
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains the microcontroller type (STM32, GD32, MKL).
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/reset_selector
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains the selected factory reset level, determined by
+		how long the rear reset button was held by the user during board
+		reset.
+
+		Format: %i.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/serial_number
+Date:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+Description:	(RO) Contains the 64-bit board serial number in hexadecimal
+		format.
+
+		Only available if board information is burned in the MCU (older
+		revisions have board information burned in the ATSHA204-A chip).
+
+		Format: %016X.
diff --git a/MAINTAINERS b/MAINTAINERS
index 5496c8ec3e1d..6516cf669cd9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2206,6 +2206,7 @@ M:	Marek Behún <kabel@kernel.org>
 S:	Maintained
 W:	https://www.turris.cz/
 F:	Documentation/ABI/testing/debugfs-moxtet
+F:	Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/ABI/testing/sysfs-firmware-turris-mox-rwtm
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
@@ -2219,10 +2220,12 @@ F:	drivers/firmware/turris-mox-rwtm.c
 F:	drivers/gpio/gpio-moxtet.c
 F:	drivers/leds/leds-turris-omnia.c
 F:	drivers/mailbox/armada-37xx-rwtm-mailbox.c
+F:	drivers/platform/cznic/
 F:	drivers/watchdog/armada_37xx_wdt.c
 F:	include/dt-bindings/bus/moxtet.h
 F:	include/linux/armada-37xx-rwtm-mailbox.h
 F:	include/linux/moxtet.h
+F:	include/linux/turris-omnia-mcu-interface.h
 
 ARM/FARADAY FA526 PORT
 M:	Hans Ulli Kroll <ulli.kroll@googlemail.com>
diff --git a/drivers/platform/Kconfig b/drivers/platform/Kconfig
index 81a298517df2..960fd6a82450 100644
--- a/drivers/platform/Kconfig
+++ b/drivers/platform/Kconfig
@@ -7,6 +7,8 @@ source "drivers/platform/goldfish/Kconfig"
 
 source "drivers/platform/chrome/Kconfig"
 
+source "drivers/platform/cznic/Kconfig"
+
 source "drivers/platform/mellanox/Kconfig"
 
 source "drivers/platform/olpc/Kconfig"
diff --git a/drivers/platform/Makefile b/drivers/platform/Makefile
index fbbe4f77aa5d..bf69cc8d7429 100644
--- a/drivers/platform/Makefile
+++ b/drivers/platform/Makefile
@@ -10,5 +10,6 @@ obj-$(CONFIG_MIPS)		+= mips/
 obj-$(CONFIG_OLPC_EC)		+= olpc/
 obj-$(CONFIG_GOLDFISH)		+= goldfish/
 obj-$(CONFIG_CHROME_PLATFORMS)	+= chrome/
+obj-$(CONFIG_CZNIC_PLATFORMS)	+= cznic/
 obj-$(CONFIG_SURFACE_PLATFORMS)	+= surface/
 obj-$(CONFIG_ARM64)		+= arm64/
diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
new file mode 100644
index 000000000000..db5f4a673d28
--- /dev/null
+++ b/drivers/platform/cznic/Kconfig
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.rst.
+#
+
+menuconfig CZNIC_PLATFORMS
+	bool "Platform support for CZ.NIC's Turris hardware"
+	help
+	  Say Y here to be able to choose driver support for CZ.NIC's Turris
+	  devices. This option alone does not add any kernel code.
+
+if CZNIC_PLATFORMS
+
+config TURRIS_OMNIA_MCU
+	tristate "Turris Omnia MCU driver"
+	depends on MACH_ARMADA_38X || COMPILE_TEST
+	depends on I2C
+	help
+	  Say Y here to add support for the features implemented by the
+	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
+	  To compile this driver as a module, choose M here; the module will be
+	  called turris-omnia-mcu.
+
+endif # CZNIC_PLATFORMS
diff --git a/drivers/platform/cznic/Makefile b/drivers/platform/cznic/Makefile
new file mode 100644
index 000000000000..31adca73bb94
--- /dev/null
+++ b/drivers/platform/cznic/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
+turris-omnia-mcu-y		:= turris-omnia-mcu-base.o
diff --git a/drivers/platform/cznic/turris-omnia-mcu-base.c b/drivers/platform/cznic/turris-omnia-mcu-base.c
new file mode 100644
index 000000000000..47513ba9b128
--- /dev/null
+++ b/drivers/platform/cznic/turris-omnia-mcu-base.c
@@ -0,0 +1,394 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CZ.NIC's Turris Omnia MCU driver
+ *
+ * 2024 by Marek Behún <kabel@kernel.org>
+ */
+
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/hex.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <linux/turris-omnia-mcu-interface.h>
+#include "turris-omnia-mcu.h"
+
+#define OMNIA_FW_VERSION_LEN		20
+#define OMNIA_FW_VERSION_HEX_LEN	(2 * OMNIA_FW_VERSION_LEN + 1)
+#define OMNIA_BOARD_INFO_LEN		16
+
+int omnia_cmd_write_read(const struct i2c_client *client,
+			 void *cmd, unsigned int cmd_len,
+			 void *reply, unsigned int reply_len)
+{
+	struct i2c_msg msgs[2];
+	int ret, num;
+
+	msgs[0].addr = client->addr;
+	msgs[0].flags = 0;
+	msgs[0].len = cmd_len;
+	msgs[0].buf = cmd;
+	num = 1;
+
+	if (reply_len) {
+		msgs[1].addr = client->addr;
+		msgs[1].flags = I2C_M_RD;
+		msgs[1].len = reply_len;
+		msgs[1].buf = reply;
+		num++;
+	}
+
+	ret = i2c_transfer(client->adapter, msgs, num);
+	if (ret < 0)
+		return ret;
+	if (ret != num)
+		return -EIO;
+
+	return 0;
+}
+
+static int omnia_get_version_hash(struct omnia_mcu *mcu, bool bootloader,
+				  char version[static OMNIA_FW_VERSION_HEX_LEN])
+{
+	u8 reply[OMNIA_FW_VERSION_LEN];
+	char *p;
+	int err;
+
+	err = omnia_cmd_read(mcu->client,
+			     bootloader ? OMNIA_CMD_GET_FW_VERSION_BOOT
+					: OMNIA_CMD_GET_FW_VERSION_APP,
+			     reply, sizeof(reply));
+	if (err)
+		return err;
+
+	p = bin2hex(version, reply, OMNIA_FW_VERSION_LEN);
+	*p = '\0';
+
+	return 0;
+}
+
+static ssize_t fw_version_hash_show(struct device *dev, char *buf,
+				    bool bootloader)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+	char version[OMNIA_FW_VERSION_HEX_LEN];
+	int err;
+
+	err = omnia_get_version_hash(mcu, bootloader, version);
+	if (err)
+		return err;
+
+	return sysfs_emit(buf, "%s\n", version);
+}
+
+static ssize_t fw_version_hash_application_show(struct device *dev,
+						struct device_attribute *a,
+						char *buf)
+{
+	return fw_version_hash_show(dev, buf, false);
+}
+static DEVICE_ATTR_RO(fw_version_hash_application);
+
+static ssize_t fw_version_hash_bootloader_show(struct device *dev,
+					       struct device_attribute *a,
+					       char *buf)
+{
+	return fw_version_hash_show(dev, buf, true);
+}
+static DEVICE_ATTR_RO(fw_version_hash_bootloader);
+
+static ssize_t fw_features_show(struct device *dev, struct device_attribute *a,
+				char *buf)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "0x%x\n", mcu->features);
+}
+static DEVICE_ATTR_RO(fw_features);
+
+static ssize_t mcu_type_show(struct device *dev, struct device_attribute *a,
+			     char *buf)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%s\n", mcu->type);
+}
+static DEVICE_ATTR_RO(mcu_type);
+
+static ssize_t reset_selector_show(struct device *dev,
+				   struct device_attribute *a, char *buf)
+{
+	u8 reply;
+	int err;
+
+	err = omnia_cmd_read_u8(to_i2c_client(dev), OMNIA_CMD_GET_RESET,
+				&reply);
+	if (err)
+		return err;
+
+	return sysfs_emit(buf, "%d\n", reply);
+}
+static DEVICE_ATTR_RO(reset_selector);
+
+static ssize_t serial_number_show(struct device *dev,
+				  struct device_attribute *a, char *buf)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%016llX\n", mcu->board_serial_number);
+}
+static DEVICE_ATTR_RO(serial_number);
+
+static ssize_t first_mac_address_show(struct device *dev,
+				      struct device_attribute *a, char *buf)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%pM\n", mcu->board_first_mac);
+}
+static DEVICE_ATTR_RO(first_mac_address);
+
+static ssize_t board_revision_show(struct device *dev,
+				   struct device_attribute *a, char *buf)
+{
+	struct omnia_mcu *mcu = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%u\n", mcu->board_revision);
+}
+static DEVICE_ATTR_RO(board_revision);
+
+static struct attribute *omnia_mcu_base_attrs[] = {
+	&dev_attr_fw_version_hash_application.attr,
+	&dev_attr_fw_version_hash_bootloader.attr,
+	&dev_attr_fw_features.attr,
+	&dev_attr_mcu_type.attr,
+	&dev_attr_reset_selector.attr,
+	&dev_attr_serial_number.attr,
+	&dev_attr_first_mac_address.attr,
+	&dev_attr_board_revision.attr,
+	NULL
+};
+
+static umode_t omnia_mcu_base_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 ((a == &dev_attr_serial_number.attr ||
+	     a == &dev_attr_first_mac_address.attr ||
+	     a == &dev_attr_board_revision.attr) &&
+	    !(mcu->features & OMNIA_FEAT_BOARD_INFO))
+		return 0;
+
+	return a->mode;
+}
+
+static const struct attribute_group omnia_mcu_base_group = {
+	.attrs = omnia_mcu_base_attrs,
+	.is_visible = omnia_mcu_base_attrs_visible,
+};
+
+static const struct attribute_group *omnia_mcu_groups[] = {
+	&omnia_mcu_base_group,
+	NULL
+};
+
+static void omnia_mcu_print_version_hash(struct omnia_mcu *mcu, bool bootloader)
+{
+	const char *type = bootloader ? "bootloader" : "application";
+	struct device *dev = &mcu->client->dev;
+	char version[OMNIA_FW_VERSION_HEX_LEN];
+	int err;
+
+	err = omnia_get_version_hash(mcu, bootloader, version);
+	if (err) {
+		dev_err(dev, "Cannot read MCU %s firmware version: %d\n",
+			type, err);
+		return;
+	}
+
+	dev_info(dev, "MCU %s firmware version hash: %s\n", type, version);
+}
+
+static const char *omnia_status_to_mcu_type(u16 status)
+{
+	switch (status & OMNIA_STS_MCU_TYPE_MASK) {
+	case OMNIA_STS_MCU_TYPE_STM32:
+		return "STM32";
+	case OMNIA_STS_MCU_TYPE_GD32:
+		return "GD32";
+	case OMNIA_STS_MCU_TYPE_MKL:
+		return "MKL";
+	default:
+		return "unknown";
+	}
+}
+
+static void omnia_info_missing_feature(struct device *dev, const char *feature)
+{
+	dev_info(dev,
+		 "Your board's MCU firmware does not support the %s feature.\n",
+		 feature);
+}
+
+static int omnia_mcu_read_features(struct omnia_mcu *mcu)
+{
+	static const struct {
+		u16 mask;
+		const char *name;
+	} features[] = {
+#define _DEF_FEAT(_n, _m) { OMNIA_FEAT_ ## _n, _m }
+		_DEF_FEAT(EXT_CMDS,		"extended control and status"),
+		_DEF_FEAT(WDT_PING,		"watchdog pinging"),
+		_DEF_FEAT(LED_STATE_EXT_MASK,	"peripheral LED pins reading"),
+		_DEF_FEAT(NEW_INT_API,		"new interrupt API"),
+		_DEF_FEAT(POWEROFF_WAKEUP,	"poweroff and wakeup"),
+		_DEF_FEAT(TRNG,			"true random number generator"),
+#undef _DEF_FEAT
+	};
+	struct i2c_client *client = mcu->client;
+	struct device *dev = &client->dev;
+	bool suggest_fw_upgrade = false;
+	u16 status;
+	int err;
+
+	/* status word holds MCU type, which we need below */
+	err = omnia_cmd_read_u16(client, OMNIA_CMD_GET_STATUS_WORD, &status);
+	if (err)
+		return err;
+
+	/*
+	 * Check whether MCU firmware supports the OMNIA_CMD_GET_FEATURES
+	 * command.
+	 */
+	if (status & OMNIA_STS_FEATURES_SUPPORTED) {
+		/* try read 32-bit features */
+		err = omnia_cmd_read_u32(client, OMNIA_CMD_GET_FEATURES,
+					 &mcu->features);
+		if (err) {
+			/* try read 16-bit features */
+			u16 features16;
+
+			err = omnia_cmd_read_u16(client, OMNIA_CMD_GET_FEATURES,
+						 &features16);
+			if (err)
+				return err;
+
+			mcu->features = features16;
+		} else {
+			if (mcu->features & OMNIA_FEAT_FROM_BIT_16_INVALID)
+				mcu->features &= GENMASK(15, 0);
+		}
+	} else {
+		dev_info(dev,
+			 "Your board's MCU firmware does not support feature reading.\n");
+		suggest_fw_upgrade = true;
+	}
+
+	mcu->type = omnia_status_to_mcu_type(status);
+	dev_info(dev, "MCU type %s%s\n", mcu->type,
+		 (mcu->features & OMNIA_FEAT_PERIPH_MCU) ?
+			", with peripheral resets wired" : "");
+
+	omnia_mcu_print_version_hash(mcu, true);
+
+	if (mcu->features & OMNIA_FEAT_BOOTLOADER)
+		dev_warn(dev,
+			 "MCU is running bootloader firmware. Was firmware upgrade interrupted?\n");
+	else
+		omnia_mcu_print_version_hash(mcu, false);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(features); i++) {
+		if (mcu->features & features[i].mask)
+			continue;
+
+		omnia_info_missing_feature(dev, features[i].name);
+		suggest_fw_upgrade = true;
+	}
+
+	if (suggest_fw_upgrade)
+		dev_info(dev,
+			 "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
+
+	return 0;
+}
+
+static int omnia_mcu_read_board_info(struct omnia_mcu *mcu)
+{
+	u8 reply[1 + OMNIA_BOARD_INFO_LEN];
+	int err;
+
+	err = omnia_cmd_read(mcu->client, OMNIA_CMD_BOARD_INFO_GET, reply,
+			     sizeof(reply));
+	if (err)
+		return err;
+
+	if (reply[0] != OMNIA_BOARD_INFO_LEN)
+		return -EIO;
+
+	mcu->board_serial_number = get_unaligned_le64(&reply[1]);
+
+	/* we can't use ether_addr_copy() because reply is not u16-aligned */
+	memcpy(mcu->board_first_mac, &reply[9], sizeof(mcu->board_first_mac));
+
+	mcu->board_revision = reply[15];
+
+	return 0;
+}
+
+static int omnia_mcu_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct omnia_mcu *mcu;
+	int err;
+
+	if (!client->irq)
+		return dev_err_probe(dev, -EINVAL, "IRQ resource not found\n");
+
+	mcu = devm_kzalloc(dev, sizeof(*mcu), GFP_KERNEL);
+	if (!mcu)
+		return -ENOMEM;
+
+	mcu->client = client;
+	i2c_set_clientdata(client, mcu);
+
+	err = omnia_mcu_read_features(mcu);
+	if (err)
+		return dev_err_probe(dev, err,
+				     "Cannot determine MCU supported features\n");
+
+	if (mcu->features & OMNIA_FEAT_BOARD_INFO) {
+		err = omnia_mcu_read_board_info(mcu);
+		if (err)
+			return dev_err_probe(dev, err,
+					     "Cannot read board info\n");
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_omnia_mcu_match[] = {
+	{ .compatible = "cznic,turris-omnia-mcu" },
+	{}
+};
+
+static struct i2c_driver omnia_mcu_driver = {
+	.probe		= omnia_mcu_probe,
+	.driver		= {
+		.name	= "turris-omnia-mcu",
+		.of_match_table = of_omnia_mcu_match,
+		.dev_groups = omnia_mcu_groups,
+	},
+};
+module_i2c_driver(omnia_mcu_driver);
+
+MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
+MODULE_DESCRIPTION("CZ.NIC's Turris Omnia MCU");
+MODULE_LICENSE("GPL");
diff --git a/drivers/platform/cznic/turris-omnia-mcu.h b/drivers/platform/cznic/turris-omnia-mcu.h
new file mode 100644
index 000000000000..3d0daa6f13ef
--- /dev/null
+++ b/drivers/platform/cznic/turris-omnia-mcu.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CZ.NIC's Turris Omnia MCU driver
+ *
+ * 2024 by Marek Behún <kabel@kernel.org>
+ */
+
+#ifndef __TURRIS_OMNIA_MCU_H
+#define __TURRIS_OMNIA_MCU_H
+
+#include <linux/if_ether.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+struct i2c_client;
+
+struct omnia_mcu {
+	struct i2c_client *client;
+	const char *type;
+	u32 features;
+
+	/* board information */
+	u64 board_serial_number;
+	u8 board_first_mac[ETH_ALEN];
+	u8 board_revision;
+};
+
+int omnia_cmd_write_read(const struct i2c_client *client,
+			 void *cmd, unsigned int cmd_len,
+			 void *reply, unsigned int reply_len);
+
+static inline int omnia_cmd_read(const struct i2c_client *client, u8 cmd,
+				 void *reply, unsigned int len)
+{
+	return omnia_cmd_write_read(client, &cmd, 1, reply, len);
+}
+
+static inline int omnia_cmd_read_u32(const struct i2c_client *client, u8 cmd,
+				     u32 *dst)
+{
+	__le32 reply;
+	int err;
+
+	err = omnia_cmd_read(client, cmd, &reply, sizeof(reply));
+	if (err)
+		return err;
+
+	*dst = le32_to_cpu(reply);
+
+	return 0;
+}
+
+static inline int omnia_cmd_read_u16(const struct i2c_client *client, u8 cmd,
+				     u16 *dst)
+{
+	__le16 reply;
+	int err;
+
+	err = omnia_cmd_read(client, cmd, &reply, sizeof(reply));
+	if (err)
+		return err;
+
+	*dst = le16_to_cpu(reply);
+
+	return 0;
+}
+
+static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd,
+				    u8 *reply)
+{
+	return omnia_cmd_read(client, cmd, reply, sizeof(*reply));
+}
+
+#endif /* __TURRIS_OMNIA_MCU_H */
diff --git a/include/linux/turris-omnia-mcu-interface.h b/include/linux/turris-omnia-mcu-interface.h
new file mode 100644
index 000000000000..2da8cbeb158a
--- /dev/null
+++ b/include/linux/turris-omnia-mcu-interface.h
@@ -0,0 +1,249 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CZ.NIC's Turris Omnia MCU I2C interface commands definitions
+ *
+ * 2024 by Marek Behún <kabel@kernel.org>
+ */
+
+#ifndef __TURRIS_OMNIA_MCU_INTERFACE_H
+#define __TURRIS_OMNIA_MCU_INTERFACE_H
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+
+enum omnia_commands_e {
+	OMNIA_CMD_GET_STATUS_WORD		= 0x01, /* slave sends status word back */
+	OMNIA_CMD_GENERAL_CONTROL		= 0x02,
+	OMNIA_CMD_LED_MODE			= 0x03, /* default/user */
+	OMNIA_CMD_LED_STATE			= 0x04, /* LED on/off */
+	OMNIA_CMD_LED_COLOR			= 0x05, /* LED number + RED + GREEN + BLUE */
+	OMNIA_CMD_USER_VOLTAGE			= 0x06,
+	OMNIA_CMD_SET_BRIGHTNESS		= 0x07,
+	OMNIA_CMD_GET_BRIGHTNESS		= 0x08,
+	OMNIA_CMD_GET_RESET			= 0x09,
+	OMNIA_CMD_GET_FW_VERSION_APP		= 0x0A, /* 20B git hash number */
+	OMNIA_CMD_SET_WATCHDOG_STATE		= 0x0B, /* 0 - disable
+							 * 1 - enable / ping
+							 * after boot watchdog is started
+							 * with 2 minutes timeout
+							 */
+
+	/* OMNIA_CMD_WATCHDOG_STATUS		= 0x0C, not implemented anymore */
+
+	OMNIA_CMD_GET_WATCHDOG_STATE		= 0x0D,
+	OMNIA_CMD_GET_FW_VERSION_BOOT		= 0x0E, /* 20B Git hash number */
+	OMNIA_CMD_GET_FW_CHECKSUM		= 0x0F, /* 4B length, 4B checksum */
+
+	/* available if FEATURES_SUPPORTED bit set in status word */
+	OMNIA_CMD_GET_FEATURES			= 0x10,
+
+	/* available if EXT_CMD bit set in features */
+	OMNIA_CMD_GET_EXT_STATUS_DWORD		= 0x11,
+	OMNIA_CMD_EXT_CONTROL			= 0x12,
+	OMNIA_CMD_GET_EXT_CONTROL_STATUS	= 0x13,
+
+	/* available if NEW_INT_API bit set in features */
+	OMNIA_CMD_GET_INT_AND_CLEAR		= 0x14,
+	OMNIA_CMD_GET_INT_MASK			= 0x15,
+	OMNIA_CMD_SET_INT_MASK			= 0x16,
+
+	/* available if FLASHING bit set in features */
+	OMNIA_CMD_FLASH				= 0x19,
+
+	/* available if WDT_PING bit set in features */
+	OMNIA_CMD_SET_WDT_TIMEOUT		= 0x20,
+	OMNIA_CMD_GET_WDT_TIMELEFT		= 0x21,
+
+	/* available if POWEROFF_WAKEUP bit set in features */
+	OMNIA_CMD_SET_WAKEUP			= 0x22,
+	OMNIA_CMD_GET_UPTIME_AND_WAKEUP		= 0x23,
+	OMNIA_CMD_POWER_OFF			= 0x24,
+
+	/* available if USB_OVC_PROT_SETTING bit set in features */
+	OMNIA_CMD_SET_USB_OVC_PROT		= 0x25,
+	OMNIA_CMD_GET_USB_OVC_PROT		= 0x26,
+
+	/* available if TRNG bit set in features */
+	OMNIA_CMD_TRNG_COLLECT_ENTROPY		= 0x28,
+
+	/* available if CRYPTO bit set in features */
+	OMNIA_CMD_CRYPTO_GET_PUBLIC_KEY		= 0x29,
+	OMNIA_CMD_CRYPTO_SIGN_MESSAGE		= 0x2A,
+	OMNIA_CMD_CRYPTO_COLLECT_SIGNATURE	= 0x2B,
+
+	/* available if BOARD_INFO it set in features */
+	OMNIA_CMD_BOARD_INFO_GET		= 0x2C,
+	OMNIA_CMD_BOARD_INFO_BURN		= 0x2D,
+
+	/* available only at address 0x2b (LED-controller) */
+	/* available only if LED_GAMMA_CORRECTION bit set in features */
+	OMNIA_CMD_SET_GAMMA_CORRECTION		= 0x30,
+	OMNIA_CMD_GET_GAMMA_CORRECTION		= 0x31,
+
+	/* available only at address 0x2b (LED-controller) */
+	/* available only if PER_LED_CORRECTION bit set in features */
+	/* available only if FROM_BIT_16_INVALID bit NOT set in features */
+	OMNIA_CMD_SET_LED_CORRECTIONS		= 0x32,
+	OMNIA_CMD_GET_LED_CORRECTIONS		= 0x33,
+};
+
+enum omnia_flashing_commands_e {
+	OMNIA_FLASH_CMD_UNLOCK		= 0x01,
+	OMNIA_FLASH_CMD_SIZE_AND_CSUM	= 0x02,
+	OMNIA_FLASH_CMD_PROGRAM		= 0x03,
+	OMNIA_FLASH_CMD_RESET		= 0x04,
+};
+
+enum omnia_sts_word_e {
+	OMNIA_STS_MCU_TYPE_MASK			= GENMASK(1, 0),
+	OMNIA_STS_MCU_TYPE_STM32		= FIELD_PREP_CONST(OMNIA_STS_MCU_TYPE_MASK, 0),
+	OMNIA_STS_MCU_TYPE_GD32			= FIELD_PREP_CONST(OMNIA_STS_MCU_TYPE_MASK, 1),
+	OMNIA_STS_MCU_TYPE_MKL			= FIELD_PREP_CONST(OMNIA_STS_MCU_TYPE_MASK, 2),
+	OMNIA_STS_FEATURES_SUPPORTED		= BIT(2),
+	OMNIA_STS_USER_REGULATOR_NOT_SUPPORTED	= BIT(3),
+	OMNIA_STS_CARD_DET			= BIT(4),
+	OMNIA_STS_MSATA_IND			= BIT(5),
+	OMNIA_STS_USB30_OVC			= BIT(6),
+	OMNIA_STS_USB31_OVC			= BIT(7),
+	OMNIA_STS_USB30_PWRON			= BIT(8),
+	OMNIA_STS_USB31_PWRON			= BIT(9),
+	OMNIA_STS_ENABLE_4V5			= BIT(10),
+	OMNIA_STS_BUTTON_MODE			= BIT(11),
+	OMNIA_STS_BUTTON_PRESSED		= BIT(12),
+	OMNIA_STS_BUTTON_COUNTER_MASK		= GENMASK(15, 13),
+};
+
+enum omnia_ctl_byte_e {
+	OMNIA_CTL_LIGHT_RST	= BIT(0),
+	OMNIA_CTL_HARD_RST	= BIT(1),
+	/* BIT(2) is currently reserved */
+	OMNIA_CTL_USB30_PWRON	= BIT(3),
+	OMNIA_CTL_USB31_PWRON	= BIT(4),
+	OMNIA_CTL_ENABLE_4V5	= BIT(5),
+	OMNIA_CTL_BUTTON_MODE	= BIT(6),
+	OMNIA_CTL_BOOTLOADER	= BIT(7),
+};
+
+enum omnia_features_e {
+	OMNIA_FEAT_PERIPH_MCU		= BIT(0),
+	OMNIA_FEAT_EXT_CMDS		= BIT(1),
+	OMNIA_FEAT_WDT_PING		= BIT(2),
+	OMNIA_FEAT_LED_STATE_EXT_MASK	= GENMASK(4, 3),
+	OMNIA_FEAT_LED_STATE_EXT	= FIELD_PREP_CONST(OMNIA_FEAT_LED_STATE_EXT_MASK, 1),
+	OMNIA_FEAT_LED_STATE_EXT_V32	= FIELD_PREP_CONST(OMNIA_FEAT_LED_STATE_EXT_MASK, 2),
+	OMNIA_FEAT_LED_GAMMA_CORRECTION	= BIT(5),
+	OMNIA_FEAT_NEW_INT_API		= BIT(6),
+	OMNIA_FEAT_BOOTLOADER		= BIT(7),
+	OMNIA_FEAT_FLASHING		= BIT(8),
+	OMNIA_FEAT_NEW_MESSAGE_API	= BIT(9),
+	OMNIA_FEAT_BRIGHTNESS_INT	= BIT(10),
+	OMNIA_FEAT_POWEROFF_WAKEUP	= BIT(11),
+	OMNIA_FEAT_CAN_OLD_MESSAGE_API	= BIT(12),
+	OMNIA_FEAT_TRNG			= BIT(13),
+	OMNIA_FEAT_CRYPTO		= BIT(14),
+	OMNIA_FEAT_BOARD_INFO		= BIT(15),
+
+	/*
+	 * Orginally the features command replied only 16 bits. If more were
+	 * read, either the I2C transaction failed or 0xff bytes were sent.
+	 * Therefore to consider bits 16 - 31 valid, one bit (20) was reserved
+	 * to be zero.
+	 */
+
+	/* Bits 16 - 19 correspond to bits 0 - 3 of status word */
+	OMNIA_FEAT_MCU_TYPE_MASK		= GENMASK(17, 16),
+	OMNIA_FEAT_MCU_TYPE_STM32		= FIELD_PREP_CONST(OMNIA_FEAT_MCU_TYPE_MASK, 0),
+	OMNIA_FEAT_MCU_TYPE_GD32		= FIELD_PREP_CONST(OMNIA_FEAT_MCU_TYPE_MASK, 1),
+	OMNIA_FEAT_MCU_TYPE_MKL			= FIELD_PREP_CONST(OMNIA_FEAT_MCU_TYPE_MASK, 2),
+	OMNIA_FEAT_FEATURES_SUPPORTED		= BIT(18),
+	OMNIA_FEAT_USER_REGULATOR_NOT_SUPPORTED	= BIT(19),
+
+	/* must not be set */
+	OMNIA_FEAT_FROM_BIT_16_INVALID	= BIT(20),
+
+	OMNIA_FEAT_PER_LED_CORRECTION	= BIT(21),
+	OMNIA_FEAT_USB_OVC_PROT_SETTING	= BIT(22),
+};
+
+enum omnia_ext_sts_dword_e {
+	OMNIA_EXT_STS_SFP_nDET		= BIT(0),
+	OMNIA_EXT_STS_LED_STATES_MASK	= GENMASK(31, 12),
+	OMNIA_EXT_STS_WLAN0_MSATA_LED	= BIT(12),
+	OMNIA_EXT_STS_WLAN1_LED		= BIT(13),
+	OMNIA_EXT_STS_WLAN2_LED		= BIT(14),
+	OMNIA_EXT_STS_WPAN0_LED		= BIT(15),
+	OMNIA_EXT_STS_WPAN1_LED		= BIT(16),
+	OMNIA_EXT_STS_WPAN2_LED		= BIT(17),
+	OMNIA_EXT_STS_WAN_LED0		= BIT(18),
+	OMNIA_EXT_STS_WAN_LED1		= BIT(19),
+	OMNIA_EXT_STS_LAN0_LED0		= BIT(20),
+	OMNIA_EXT_STS_LAN0_LED1		= BIT(21),
+	OMNIA_EXT_STS_LAN1_LED0		= BIT(22),
+	OMNIA_EXT_STS_LAN1_LED1		= BIT(23),
+	OMNIA_EXT_STS_LAN2_LED0		= BIT(24),
+	OMNIA_EXT_STS_LAN2_LED1		= BIT(25),
+	OMNIA_EXT_STS_LAN3_LED0		= BIT(26),
+	OMNIA_EXT_STS_LAN3_LED1		= BIT(27),
+	OMNIA_EXT_STS_LAN4_LED0		= BIT(28),
+	OMNIA_EXT_STS_LAN4_LED1		= BIT(29),
+	OMNIA_EXT_STS_LAN5_LED0		= BIT(30),
+	OMNIA_EXT_STS_LAN5_LED1		= BIT(31),
+};
+
+enum omnia_ext_ctl_e {
+	OMNIA_EXT_CTL_nRES_MMC		= BIT(0),
+	OMNIA_EXT_CTL_nRES_LAN		= BIT(1),
+	OMNIA_EXT_CTL_nRES_PHY		= BIT(2),
+	OMNIA_EXT_CTL_nPERST0		= BIT(3),
+	OMNIA_EXT_CTL_nPERST1		= BIT(4),
+	OMNIA_EXT_CTL_nPERST2		= BIT(5),
+	OMNIA_EXT_CTL_PHY_SFP		= BIT(6),
+	OMNIA_EXT_CTL_PHY_SFP_AUTO	= BIT(7),
+	OMNIA_EXT_CTL_nVHV_CTRL		= BIT(8),
+};
+
+enum omnia_int_e {
+	OMNIA_INT_CARD_DET		= BIT(0),
+	OMNIA_INT_MSATA_IND		= BIT(1),
+	OMNIA_INT_USB30_OVC		= BIT(2),
+	OMNIA_INT_USB31_OVC		= BIT(3),
+	OMNIA_INT_BUTTON_PRESSED	= BIT(4),
+	OMNIA_INT_SFP_nDET		= BIT(5),
+	OMNIA_INT_BRIGHTNESS_CHANGED	= BIT(6),
+	OMNIA_INT_TRNG			= BIT(7),
+	OMNIA_INT_MESSAGE_SIGNED	= BIT(8),
+
+	OMNIA_INT_LED_STATES_MASK	= GENMASK(31, 12),
+	OMNIA_INT_WLAN0_MSATA_LED	= BIT(12),
+	OMNIA_INT_WLAN1_LED		= BIT(13),
+	OMNIA_INT_WLAN2_LED		= BIT(14),
+	OMNIA_INT_WPAN0_LED		= BIT(15),
+	OMNIA_INT_WPAN1_LED		= BIT(16),
+	OMNIA_INT_WPAN2_LED		= BIT(17),
+	OMNIA_INT_WAN_LED0		= BIT(18),
+	OMNIA_INT_WAN_LED1		= BIT(19),
+	OMNIA_INT_LAN0_LED0		= BIT(20),
+	OMNIA_INT_LAN0_LED1		= BIT(21),
+	OMNIA_INT_LAN1_LED0		= BIT(22),
+	OMNIA_INT_LAN1_LED1		= BIT(23),
+	OMNIA_INT_LAN2_LED0		= BIT(24),
+	OMNIA_INT_LAN2_LED1		= BIT(25),
+	OMNIA_INT_LAN3_LED0		= BIT(26),
+	OMNIA_INT_LAN3_LED1		= BIT(27),
+	OMNIA_INT_LAN4_LED0		= BIT(28),
+	OMNIA_INT_LAN4_LED1		= BIT(29),
+	OMNIA_INT_LAN5_LED0		= BIT(30),
+	OMNIA_INT_LAN5_LED1		= BIT(31),
+};
+
+enum omnia_cmd_poweroff_e {
+	OMNIA_CMD_POWER_OFF_POWERON_BUTTON	= BIT(0),
+	OMNIA_CMD_POWER_OFF_MAGIC		= 0xdead,
+};
+
+enum omnia_cmd_usb_ovc_prot_e {
+	OMNIA_CMD_xET_USB_OVC_PROT_PORT_MASK	= GENMASK(3, 0),
+	OMNIA_CMD_xET_USB_OVC_PROT_ENABLE	= BIT(4),
+};
+
+#endif /* __TURRIS_OMNIA_MCU_INTERFACE_H */
-- 
2.44.2

[PATCH v12 4/8] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup

[Marek Behún]

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@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
---
 .../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   | 260 ++++++++++++++++++
 drivers/platform/cznic/turris-omnia-mcu.h     |  20 ++
 6 files changed, 306 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 86360249080c..307a55f599cb 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:		September 2024
+KernelVersion:	6.11
+Contact:	Marek Behún <kabel@kernel.org>
+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:		September 2024
 KernelVersion:	6.11
diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
index d95e7c83c7ae..c1e719235517 100644
--- a/drivers/platform/cznic/Kconfig
+++ b/drivers/platform/cznic/Kconfig
@@ -18,10 +18,14 @@ 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 4481484b2f94..338a7ab12bd0 100644
--- a/drivers/platform/cznic/turris-omnia-mcu-base.c
+++ b/drivers/platform/cznic/turris-omnia-mcu-base.c
@@ -198,6 +198,7 @@ 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
 };
 
@@ -372,6 +373,10 @@ 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..0e8ab15b6037
--- /dev/null
+++ b/drivers/platform/cznic/turris-omnia-mcu-sys-off-wakeup.c
@@ -0,0 +1,260 @@
+// 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@kernel.org>
+ */
+
+#include <linux/crc32.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/kstrtox.h>
+#include <linux/reboot.h>
+#include <linux/rtc.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+
+#include <linux/turris-omnia-mcu-interface.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, OMNIA_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, OMNIA_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, OMNIA_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 = OMNIA_CMD_POWER_OFF_POWERON_BUTTON;
+	else
+		arg = 0;
+
+	cmd[0] = OMNIA_CMD_POWER_OFF;
+	put_unaligned_le16(OMNIA_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(~0, (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] = OMNIA_CMD_GENERAL_CONTROL;
+
+	if (reboot_mode == REBOOT_HARD)
+		cmd[1] = cmd[2] = OMNIA_CTL_HARD_RST;
+	else
+		cmd[1] = cmd[2] = OMNIA_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 & OMNIA_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 & OMNIA_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 3d2dd0054499..2a1c68ba9b7f 100644
--- a/drivers/platform/cznic/turris-omnia-mcu.h
+++ b/drivers/platform/cznic/turris-omnia-mcu.h
@@ -15,8 +15,10 @@
 #include <linux/types.h>
 #include <linux/workqueue.h>
 #include <asm/byteorder.h>
+#include <asm/unaligned.h>
 
 struct i2c_client;
+struct rtc_device;
 
 struct omnia_mcu {
 	struct i2c_client *client;
@@ -36,6 +38,11 @@ struct omnia_mcu {
 	struct delayed_work button_release_emul_work;
 	unsigned long 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,
@@ -48,6 +55,17 @@ 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)
 {
@@ -136,7 +154,9 @@ 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 */
-- 
2.44.2

Re: [PATCH v12 0/8] Turris Omnia MCU driver

[Marek Behún]

Hi Arnd,

will you be merging this series?

Thanks.

Marek

Re: [PATCH v12 0/8] Turris Omnia MCU driver

[Marek Behún]

On Mon, 1 Jul 2024 10:41:15 +0200
Marek Behún <kabel@kernel.org> wrote:

> Hi Arnd,
> 
> will you be merging this series?

Just to clear up, I wanted to ask whether you will be merging or
someone else should take stuff to drivers/platform.

Anyway, I sent v13 with one more cosmetic change, requested by Bart.

Marek

Re: [PATCH v12 4/8] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup

[Nathan Chancellor]

Hi Marek,

On Mon, Jun 17, 2024 at 05:26:02PM +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@kernel.org>
> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Reviewed-by: Andy Shevchenko <andy@kernel.org>
...
> diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
> index d95e7c83c7ae..c1e719235517 100644
> --- a/drivers/platform/cznic/Kconfig
> +++ b/drivers/platform/cznic/Kconfig
> @@ -18,10 +18,14 @@ 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

I am seeing the following Kconfig warning from ARCH=s390 allmodconfig:

WARNING: unmet direct dependencies detected for RTC_CLASS
  Depends on [n]: !S390 [=y]
  Selected by [m]:
  - TURRIS_OMNIA_MCU [=m] && CZNIC_PLATFORMS [=y] && (MACH_ARMADA_38X || COMPILE_TEST [=y]) && I2C [=m] && OF [=y] && WATCHDOG [=y]

because of:

menuconfig RTC_CLASS
    bool "Real Time Clock"
    default n
    depends on !S390

which appears to have ultimately come from commit 9556fb73edfc ("[S390]
Kconfig: unwanted menus for s390."). No other driver appears to
unconditionally select this (I only see it selected within
arch/*/Kconfig), so it does not look like this has come up before.
Should s390 be excluded from the COMPILE_TEST dependency?

Cheers,
Nathan

Re: [PATCH v12 4/8] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup

[Arnd Bergmann]

On Mon, Jul 15, 2024, at 05:24, Nathan Chancellor wrote:
> On Mon, Jun 17, 2024 at 05:26:02PM +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@kernel.org>
>> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
>> Reviewed-by: Andy Shevchenko <andy@kernel.org>
> ...
>> diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
>> index d95e7c83c7ae..c1e719235517 100644
>> --- a/drivers/platform/cznic/Kconfig
>> +++ b/drivers/platform/cznic/Kconfig
>> @@ -18,10 +18,14 @@ 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
>
> I am seeing the following Kconfig warning from ARCH=s390 allmodconfig:
>
> WARNING: unmet direct dependencies detected for RTC_CLASS
>   Depends on [n]: !S390 [=y]
>   Selected by [m]:
>   - TURRIS_OMNIA_MCU [=m] && CZNIC_PLATFORMS [=y] && (MACH_ARMADA_38X 
> || COMPILE_TEST [=y]) && I2C [=m] && OF [=y] && WATCHDOG [=y]
>
> because of:
>
> menuconfig RTC_CLASS
>     bool "Real Time Clock"
>     default n
>     depends on !S390
>
> which appears to have ultimately come from commit 9556fb73edfc ("[S390]
> Kconfig: unwanted menus for s390."). No other driver appears to
> unconditionally select this (I only see it selected within
> arch/*/Kconfig), so it does not look like this has come up before.
> Should s390 be excluded from the COMPILE_TEST dependency?

There is really no reason for a driver to select another subsystem,
it not just causes problems like this one but also leads to
circular dependencies and surprises when someone turns on
a random driver and then turns it off again, leaving the
the other subsystems accidentally enabled.

I've applied the fixup below now, leaving GPIOLIB_IRQCHIP
as the only selected symbol since this is not user-visible.

Marek, you could consider changing the driver so it doesn't
actually require all those subsystems at build time but instead
just leaves out the functionality. Some subsystems actually
have a stub implementation that makes it work by just dropping
the dependency, but I did not try that here.

    Arnd

8<------------
commit ed46f1f7731d2cd77d623c0f895df9e23c0bffb6
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Mon Jul 15 08:02:30 2024 +0200

    platform: cznic: turris-omnia-mcu: fix Kconfig dependencies
    
    The newly added driver causes a Kconfig warning:
    
    WARNING: unmet direct dependencies detected for RTC_CLASS
      Depends on [n]: !S390 [=y]
      Selected by [m]:
      - TURRIS_OMNIA_MCU [=m] && CZNIC_PLATFORMS [=y] && (MACH_ARMADA_38X || COMPILE_TEST [=y]) && I2C [=m] && OF [=y] && WATCHDOG [=y]
    
    The problem here is that it selects entire subsystems, which normal
    device drivers should not do. Changes all of these to 'depends on'
    instead.
    
    Fixes: dfa556e45ae9e ("platform: cznic: turris-omnia-mcu: Add support for MCU connected GPIOs")
    Fixes: 90e700fd12b61 ("platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup")
    Fixes: ab89fb5fb92c7 ("platform: cznic: turris-omnia-mcu: Add support for MCU watchdog")
    Fixes: 41bb142a40289 ("platform: cznic: turris-omnia-mcu: Add support for MCU provided TRNG")
    Reported-by: Nathan Chancellor <nathan@kernel.org>
    Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/platform/cznic/Kconfig b/drivers/platform/cznic/Kconfig
index 2a5235cf6844..cb0d4d686d8a 100644
--- a/drivers/platform/cznic/Kconfig
+++ b/drivers/platform/cznic/Kconfig
@@ -18,11 +18,11 @@ config TURRIS_OMNIA_MCU
 	depends on I2C
 	depends on OF
 	depends on WATCHDOG
-	select GPIOLIB
+	depends on GPIOLIB
+	depends on HW_RANDOM
+	depends on RTC_CLASS
+	depends on WATCHDOG_CORE
 	select GPIOLIB_IRQCHIP
-	select HW_RANDOM
-	select RTC_CLASS
-	select WATCHDOG_CORE
 	help
 	  Say Y here to add support for the features implemented by the
 	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.

Re: [PATCH v12 4/8] platform: cznic: turris-omnia-mcu: Add support for poweroff and wakeup

[Marek Behún]

On Mon, Jul 15, 2024 at 08:12:39AM +0200, Arnd Bergmann wrote:
> On Mon, Jul 15, 2024, at 05:24, Nathan Chancellor wrote:
> > On Mon, Jun 17, 2024 at 05:26:02PM +0200, Marek Behún wrote:
...
> >
> > I am seeing the following Kconfig warning from ARCH=s390 allmodconfig:
> >
> > WARNING: unmet direct dependencies detected for RTC_CLASS
> >   Depends on [n]: !S390 [=y]
> >   Selected by [m]:
> >   - TURRIS_OMNIA_MCU [=m] && CZNIC_PLATFORMS [=y] && (MACH_ARMADA_38X 
> > || COMPILE_TEST [=y]) && I2C [=m] && OF [=y] && WATCHDOG [=y]
> >
> > because of:
> >
> > menuconfig RTC_CLASS
> >     bool "Real Time Clock"
> >     default n
> >     depends on !S390
> >
> > which appears to have ultimately come from commit 9556fb73edfc ("[S390]
> > Kconfig: unwanted menus for s390."). No other driver appears to
> > unconditionally select this (I only see it selected within
> > arch/*/Kconfig), so it does not look like this has come up before.
> > Should s390 be excluded from the COMPILE_TEST dependency?
> 
> There is really no reason for a driver to select another subsystem,
> it not just causes problems like this one but also leads to
> circular dependencies and surprises when someone turns on
> a random driver and then turns it off again, leaving the
> the other subsystems accidentally enabled.

Makes sense.

> I've applied the fixup below now, leaving GPIOLIB_IRQCHIP
> as the only selected symbol since this is not user-visible.

Thanks.

> Marek, you could consider changing the driver so it doesn't
> actually require all those subsystems at build time but instead
> just leaves out the functionality. Some subsystems actually
> have a stub implementation that makes it work by just dropping
> the dependency, but I did not try that here.

I will look into that.

Marek