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authorHeiko Stuebner <heiko@sntech.de>2024-11-07 12:47:07 +0100
committerLee Jones <lee@kernel.org>2024-12-17 13:14:33 +0000
commit998f70d1806bb718a7565f350283e4a79c8cbb4b (patch)
treed182f6326857ab87405b63df22cdde7b03a5c084 /include/linux/mfd
parent3f674e74570e82100aa20aae82da742f07b9310c (diff)
mfd: Add base driver for qnap-mcu devices
These microcontroller units are used in network-attached-storage devices made by QNAP and provide additional functionality to the system. This adds the base driver that implements the serial protocol via serdev and additionally hooks into the poweroff handlers to turn off the parts of the system not supplied by the general PMIC. Turning off (at least the TSx33 devices using Rockchip SoCs) consists of two separate actions. Turning off the MCU alone does not turn off the main SoC and turning off only the SoC/PMIC does not turn off the hard-drives. Also if the MCU is not turned off, the system also won't start again until it is unplugged from power. So on shutdown the MCU needs to be turned off separately before the main PMIC. The protocol spoken by the MCU is sadly not documented, but was obtained by listening to the chatter on the serial port, as thankfully the "hal_app" program from QNAPs firmware allows triggering all/most MCU actions from the command line. The implementation of how to talk to the serial device got some inspiration from the rave-sp servdev driver. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20241107114712.538976-5-heiko@sntech.de Signed-off-by: Lee Jones <lee@kernel.org>
Diffstat (limited to 'include/linux/mfd')
-rw-r--r--include/linux/mfd/qnap-mcu.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/mfd/qnap-mcu.h b/include/linux/mfd/qnap-mcu.h
new file mode 100644
index 000000000000..8d48c212fd44
--- /dev/null
+++ b/include/linux/mfd/qnap-mcu.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Core definitions for QNAP MCU MFD driver.
+ * Copyright (C) 2024 Heiko Stuebner <heiko@sntech.de>
+ */
+
+#ifndef _LINUX_QNAP_MCU_H_
+#define _LINUX_QNAP_MCU_H_
+
+struct qnap_mcu;
+
+struct qnap_mcu_variant {
+ u32 baud_rate;
+ int num_drives;
+ int fan_pwm_min;
+ int fan_pwm_max;
+ bool usb_led;
+};
+
+int qnap_mcu_exec(struct qnap_mcu *mcu,
+ const u8 *cmd_data, size_t cmd_data_size,
+ u8 *reply_data, size_t reply_data_size);
+int qnap_mcu_exec_with_ack(struct qnap_mcu *mcu,
+ const u8 *cmd_data, size_t cmd_data_size);
+
+#endif /* _LINUX_QNAP_MCU_H_ */