linux/drivers/mfd/khadas-mcu.c
Neil Armstrong 6c27219e34 mfd: Add support for the Khadas System control Microcontroller
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@baylibre.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-06-18 11:23:16 +01:00

143 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Driver for Khadas System control Microcontroller
*
* Copyright (C) 2020 BayLibre SAS
*
* Author(s): Neil Armstrong <narmstrong@baylibre.com>
*/
#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@baylibre.com>");
MODULE_LICENSE("GPL v2");