diff options
Diffstat (limited to 'drivers/power/reset/tdx-ec-poweroff.c')
| -rw-r--r-- | drivers/power/reset/tdx-ec-poweroff.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/drivers/power/reset/tdx-ec-poweroff.c b/drivers/power/reset/tdx-ec-poweroff.c new file mode 100644 index 000000000000..3302a127fce5 --- /dev/null +++ b/drivers/power/reset/tdx-ec-poweroff.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Toradex Embedded Controller driver + * + * Copyright (C) 2025 Toradex + * + * Author: Emanuele Ghidoli <emanuele.ghidoli@toradex.com> + */ + +#include <linux/array_size.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/reboot.h> +#include <linux/regmap.h> +#include <linux/types.h> + +#define EC_CHIP_ID_REG 0x00 +#define EC_CHIP_ID_SMARC_IMX95 0x11 +#define EC_CHIP_ID_SMARC_IMX8MP 0x12 + +#define EC_VERSION_REG_MAJOR 0x01 +#define EC_VERSION_REG_MINOR 0x02 +#define EC_ID_VERSION_LEN 3 + +#define EC_CMD_REG 0xD0 +#define EC_CMD_POWEROFF 0x01 +#define EC_CMD_RESET 0x02 + +#define EC_REG_MAX 0xD0 + +static const struct regmap_range volatile_ranges[] = { + regmap_reg_range(EC_CMD_REG, EC_CMD_REG), +}; + +static const struct regmap_access_table volatile_table = { + .yes_ranges = volatile_ranges, + .n_yes_ranges = ARRAY_SIZE(volatile_ranges), +}; + +static const struct regmap_range read_ranges[] = { + regmap_reg_range(EC_CHIP_ID_REG, EC_VERSION_REG_MINOR), +}; + +static const struct regmap_access_table read_table = { + .yes_ranges = read_ranges, + .n_yes_ranges = ARRAY_SIZE(read_ranges), +}; + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = EC_REG_MAX, + .cache_type = REGCACHE_RBTREE, + .rd_table = &read_table, + .volatile_table = &volatile_table, +}; + +static int tdx_ec_cmd(struct regmap *regmap, u8 cmd) +{ + int err = regmap_write(regmap, EC_CMD_REG, cmd); + + if (err) + dev_err(regmap_get_device(regmap), "Failed to send command 0x%02X: %d\n", cmd, err); + + return err; +} + +static int tdx_ec_power_off(struct sys_off_data *data) +{ + struct regmap *regmap = data->cb_data; + int err; + + err = tdx_ec_cmd(regmap, EC_CMD_POWEROFF); + + return err ? NOTIFY_BAD : NOTIFY_DONE; +} + +static int tdx_ec_restart(struct sys_off_data *data) +{ + struct regmap *regmap = data->cb_data; + int err; + + err = tdx_ec_cmd(regmap, EC_CMD_RESET); + + return err ? NOTIFY_BAD : NOTIFY_DONE; +} + +static int tdx_ec_register_power_off_restart(struct device *dev, struct regmap *regmap) +{ + int err; + + err = devm_register_sys_off_handler(dev, SYS_OFF_MODE_RESTART, + SYS_OFF_PRIO_FIRMWARE, + tdx_ec_restart, regmap); + if (err) + return err; + + return devm_register_sys_off_handler(dev, SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_FIRMWARE, + tdx_ec_power_off, regmap); +} + +static int tdx_ec_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + u8 reg_val[EC_ID_VERSION_LEN]; + struct regmap *regmap; + int err; + + regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + err = regmap_bulk_read(regmap, EC_CHIP_ID_REG, ®_val, EC_ID_VERSION_LEN); + if (err) + return dev_err_probe(dev, err, + "Cannot read id and version registers\n"); + + dev_info(dev, "Toradex Embedded Controller id %x - Firmware %u.%u\n", + reg_val[0], reg_val[1], reg_val[2]); + + err = tdx_ec_register_power_off_restart(dev, regmap); + if (err) + return dev_err_probe(dev, err, + "Cannot register system restart handler\n"); + + return 0; +} + +static const struct of_device_id __maybe_unused of_tdx_ec_match[] = { + { .compatible = "toradex,smarc-ec" }, + {} +}; +MODULE_DEVICE_TABLE(of, of_tdx_ec_match); + +static struct i2c_driver tdx_ec_driver = { + .probe = tdx_ec_probe, + .driver = { + .name = "toradex-smarc-ec", + .of_match_table = of_tdx_ec_match, + }, +}; +module_i2c_driver(tdx_ec_driver); + +MODULE_AUTHOR("Emanuele Ghidoli <emanuele.ghidoli@toradex.com>"); +MODULE_DESCRIPTION("Toradex SMARC Embedded Controller driver"); +MODULE_LICENSE("GPL"); |