[PATCH v3 2/5] mfd: add support for the Khadas System control Microcontroller

From: Neil Armstrong
Date: Mon Jun 08 2020 - 05:18:11 EST

This Microcontroller is present on the Khadas VIM1, VIM2, VIM3 and Edge
boards.

It has multiple boot control features like password check, power-on
options, power-off control and system FAN control on recent boards.

This implements a very basic MFD driver with the fan control and User
NVMEM cells.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/mfd/Kconfig | 21 +++++
drivers/mfd/Makefile | 1 +
drivers/mfd/khadas-mcu.c | 142 +++++++++++++++++++++++++++++++++
include/linux/mfd/khadas-mcu.h | 91 +++++++++++++++++++++
4 files changed, 255 insertions(+)
create mode 100644 drivers/mfd/khadas-mcu.c
create mode 100644 include/linux/mfd/khadas-mcu.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 0a59249198d3..61ffade36363 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2003,6 +2003,27 @@ config MFD_WCD934X
This driver provides common support WCD934x audio codec and its
associated Pin Controller, Soundwire Controller and Audio codec.

+config MFD_KHADAS_MCU
+ tristate "Support for Khadas System control Microcontroller"
+ depends on I2C
+ depends on ARCH_MESON || ARCH_ROCKCHIP || COMPILE_TEST
+ select MFD_CORE
+ select REGMAP_I2C
+ help
+ Support for the Khadas System control Microcontroller interface
+ present on their VIM and Edge boards.
+
+ This Microcontroller is present on the Khadas VIM1, VIM2, VIM3 and
+ Edge boards.
+
+ It provides multiple boot control features like password check,
+ power-on options, power-off control and system FAN control on recent
+ boards.
+
+ This driver provides common support for accessing the device,
+ additional drivers must be enabled in order to use the functionality
+ of the device.
+
menu "Multimedia Capabilities Port drivers"
depends on ARCH_SA1100

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index f935d10cbf0f..0f1633b096bb 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -257,5 +257,6 @@ obj-$(CONFIG_MFD_ROHM_BD70528) += rohm-bd70528.o
obj-$(CONFIG_MFD_ROHM_BD71828) += rohm-bd71828.o
obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o
obj-$(CONFIG_MFD_STMFX) += stmfx.o
+obj-$(CONFIG_MFD_KHADAS_MCU) += khadas-mcu.o

obj-$(CONFIG_SGI_MFD_IOC3) += ioc3.o
diff --git a/drivers/mfd/khadas-mcu.c b/drivers/mfd/khadas-mcu.c
new file mode 100644
index 000000000000..44d5bb462dab
--- /dev/null
+++ b/drivers/mfd/khadas-mcu.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Khadas System control Microcontroller
+ *
+ * Copyright (C) 2020 BayLibre SAS
+ *
+ * Author(s): Neil Armstrong <narmstrong@xxxxxxxxxxxx>
+ */
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/khadas-mcu.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+static bool khadas_mcu_reg_volatile(struct device *dev, unsigned int reg)
+{
+ if (reg >= KHADAS_MCU_USER_DATA_0_REG &&
+ reg < KHADAS_MCU_PWR_OFF_CMD_REG)
+ return true;
+
+ switch (reg) {
+ case KHADAS_MCU_PWR_OFF_CMD_REG:
+ case KHADAS_MCU_PASSWD_START_REG:
+ case KHADAS_MCU_CHECK_VEN_PASSWD_REG:
+ case KHADAS_MCU_CHECK_USER_PASSWD_REG:
+ case KHADAS_MCU_WOL_INIT_START_REG:
+ case KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool khadas_mcu_reg_writeable(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case KHADAS_MCU_PASSWD_VEN_0_REG:
+ case KHADAS_MCU_PASSWD_VEN_1_REG:
+ case KHADAS_MCU_PASSWD_VEN_2_REG:
+ case KHADAS_MCU_PASSWD_VEN_3_REG:
+ case KHADAS_MCU_PASSWD_VEN_4_REG:
+ case KHADAS_MCU_PASSWD_VEN_5_REG:
+ case KHADAS_MCU_MAC_0_REG:
+ case KHADAS_MCU_MAC_1_REG:
+ case KHADAS_MCU_MAC_2_REG:
+ case KHADAS_MCU_MAC_3_REG:
+ case KHADAS_MCU_MAC_4_REG:
+ case KHADAS_MCU_MAC_5_REG:
+ case KHADAS_MCU_USID_0_REG:
+ case KHADAS_MCU_USID_1_REG:
+ case KHADAS_MCU_USID_2_REG:
+ case KHADAS_MCU_USID_3_REG:
+ case KHADAS_MCU_USID_4_REG:
+ case KHADAS_MCU_USID_5_REG:
+ case KHADAS_MCU_VERSION_0_REG:
+ case KHADAS_MCU_VERSION_1_REG:
+ case KHADAS_MCU_DEVICE_NO_0_REG:
+ case KHADAS_MCU_DEVICE_NO_1_REG:
+ case KHADAS_MCU_FACTORY_TEST_REG:
+ case KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG:
+ return false;
+ default:
+ return true;
+ }
+}
+
+static const struct regmap_config khadas_mcu_regmap_config = {
+ .reg_bits = 8,
+ .reg_stride = 1,
+ .val_bits = 8,
+ .max_register = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
+ .volatile_reg = khadas_mcu_reg_volatile,
+ .writeable_reg = khadas_mcu_reg_writeable,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static struct mfd_cell khadas_mcu_fan_cells[] = {
+ /* VIM1/2 Rev13+ and VIM3 only */
+ { .name = "khadas-mcu-fan-ctrl", },
+};
+
+static struct mfd_cell khadas_mcu_cells[] = {
+ { .name = "khadas-mcu-user-mem", },
+};
+
+static int khadas_mcu_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct khadas_mcu *ddata;
+ int ret;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ddata);
+
+ ddata->dev = dev;
+
+ ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
+ if (IS_ERR(ddata->regmap)) {
+ ret = PTR_ERR(ddata->regmap);
+ dev_err(dev, "Failed to allocate register map: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+ khadas_mcu_cells,
+ ARRAY_SIZE(khadas_mcu_cells),
+ NULL, 0, NULL);
+ if (ret)
+ return ret;
+
+ if (of_find_property(dev->of_node, "#cooling-cells", NULL))
+ return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+ khadas_mcu_fan_cells,
+ ARRAY_SIZE(khadas_mcu_fan_cells),
+ NULL, 0, NULL);
+
+ return 0;
+}
+
+static const struct of_device_id khadas_mcu_of_match[] = {
+ { .compatible = "khadas,mcu", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, khadas_mcu_of_match);
+
+static struct i2c_driver khadas_mcu_driver = {
+ .driver = {
+ .name = "khadas-mcu-core",
+ .of_match_table = of_match_ptr(khadas_mcu_of_match),
+ },
+ .probe = khadas_mcu_probe,
+};
+module_i2c_driver(khadas_mcu_driver);
+
+MODULE_DESCRIPTION("Khadas MCU core driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@xxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/khadas-mcu.h b/include/linux/mfd/khadas-mcu.h
new file mode 100644
index 000000000000..a99ba2ed0e4e
--- /dev/null
+++ b/include/linux/mfd/khadas-mcu.h
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Khadas System control Microcontroller Register map
+ *
+ * Copyright (C) 2020 BayLibre SAS
+ *
+ * Author(s): Neil Armstrong <narmstrong@xxxxxxxxxxxx>
+ */
+
+#ifndef MFD_KHADAS_MCU_H
+#define MFD_KHADAS_MCU_H
+
+#define KHADAS_MCU_PASSWD_VEN_0_REG 0x00 /* RO */
+#define KHADAS_MCU_PASSWD_VEN_1_REG 0x01 /* RO */
+#define KHADAS_MCU_PASSWD_VEN_2_REG 0x02 /* RO */
+#define KHADAS_MCU_PASSWD_VEN_3_REG 0x03 /* RO */
+#define KHADAS_MCU_PASSWD_VEN_4_REG 0x04 /* RO */
+#define KHADAS_MCU_PASSWD_VEN_5_REG 0x05 /* RO */
+#define KHADAS_MCU_MAC_0_REG 0x06 /* RO */
+#define KHADAS_MCU_MAC_1_REG 0x07 /* RO */
+#define KHADAS_MCU_MAC_2_REG 0x08 /* RO */
+#define KHADAS_MCU_MAC_3_REG 0x09 /* RO */
+#define KHADAS_MCU_MAC_4_REG 0x0a /* RO */
+#define KHADAS_MCU_MAC_5_REG 0x0b /* RO */
+#define KHADAS_MCU_USID_0_REG 0x0c /* RO */
+#define KHADAS_MCU_USID_1_REG 0x0d /* RO */
+#define KHADAS_MCU_USID_2_REG 0x0e /* RO */
+#define KHADAS_MCU_USID_3_REG 0x0f /* RO */
+#define KHADAS_MCU_USID_4_REG 0x10 /* RO */
+#define KHADAS_MCU_USID_5_REG 0x11 /* RO */
+#define KHADAS_MCU_VERSION_0_REG 0x12 /* RO */
+#define KHADAS_MCU_VERSION_1_REG 0x13 /* RO */
+#define KHADAS_MCU_DEVICE_NO_0_REG 0x14 /* RO */
+#define KHADAS_MCU_DEVICE_NO_1_REG 0x15 /* RO */
+#define KHADAS_MCU_FACTORY_TEST_REG 0x16 /* R */
+#define KHADAS_MCU_BOOT_MODE_REG 0x20 /* RW */
+#define KHADAS_MCU_BOOT_EN_WOL_REG 0x21 /* RW */
+#define KHADAS_MCU_BOOT_EN_RTC_REG 0x22 /* RW */
+#define KHADAS_MCU_BOOT_EN_EXP_REG 0x23 /* RW */
+#define KHADAS_MCU_BOOT_EN_IR_REG 0x24 /* RW */
+#define KHADAS_MCU_BOOT_EN_DCIN_REG 0x25 /* RW */
+#define KHADAS_MCU_BOOT_EN_KEY_REG 0x26 /* RW */
+#define KHADAS_MCU_KEY_MODE_REG 0x27 /* RW */
+#define KHADAS_MCU_LED_MODE_ON_REG 0x28 /* RW */
+#define KHADAS_MCU_LED_MODE_OFF_REG 0x29 /* RW */
+#define KHADAS_MCU_SHUTDOWN_NORMAL_REG 0x2c /* RW */
+#define KHADAS_MCU_MAC_SWITCH_REG 0x2d /* RW */
+#define KHADAS_MCU_MCU_SLEEP_MODE_REG 0x2e /* RW */
+#define KHADAS_MCU_IR_CODE1_0_REG 0x2f /* RW */
+#define KHADAS_MCU_IR_CODE1_1_REG 0x30 /* RW */
+#define KHADAS_MCU_IR_CODE1_2_REG 0x31 /* RW */
+#define KHADAS_MCU_IR_CODE1_3_REG 0x32 /* RW */
+#define KHADAS_MCU_USB_PCIE_SWITCH_REG 0x33 /* RW */
+#define KHADAS_MCU_IR_CODE2_0_REG 0x34 /* RW */
+#define KHADAS_MCU_IR_CODE2_1_REG 0x35 /* RW */
+#define KHADAS_MCU_IR_CODE2_2_REG 0x36 /* RW */
+#define KHADAS_MCU_IR_CODE2_3_REG 0x37 /* RW */
+#define KHADAS_MCU_PASSWD_USER_0_REG 0x40 /* RW */
+#define KHADAS_MCU_PASSWD_USER_1_REG 0x41 /* RW */
+#define KHADAS_MCU_PASSWD_USER_2_REG 0x42 /* RW */
+#define KHADAS_MCU_PASSWD_USER_3_REG 0x43 /* RW */
+#define KHADAS_MCU_PASSWD_USER_4_REG 0x44 /* RW */
+#define KHADAS_MCU_PASSWD_USER_5_REG 0x45 /* RW */
+#define KHADAS_MCU_USER_DATA_0_REG 0x46 /* RW 56 bytes */
+#define KHADAS_MCU_PWR_OFF_CMD_REG 0x80 /* WO */
+#define KHADAS_MCU_PASSWD_START_REG 0x81 /* WO */
+#define KHADAS_MCU_CHECK_VEN_PASSWD_REG 0x82 /* WO */
+#define KHADAS_MCU_CHECK_USER_PASSWD_REG 0x83 /* WO */
+#define KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG 0x86 /* RO */
+#define KHADAS_MCU_WOL_INIT_START_REG 0x87 /* WO */
+#define KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG 0x88 /* WO */
+
+enum {
+ KHADAS_BOARD_VIM1 = 0x1,
+ KHADAS_BOARD_VIM2,
+ KHADAS_BOARD_VIM3,
+ KHADAS_BOARD_EDGE = 0x11,
+ KHADAS_BOARD_EDGE_V,
+};
+
+/**
+ * struct khadas_mcu - Khadas MCU structure
+ * @device: device reference used for logs
+ * @regmap: register map
+ */
+struct khadas_mcu {
+ struct device *dev;
+ struct regmap *regmap;
+};
+
+#endif /* MFD_KHADAS_MCU_H */
--
2.22.0