diff options
Diffstat (limited to 'drivers/hwmon/sbrmi.c')
| -rw-r--r-- | drivers/hwmon/sbrmi.c | 357 |
1 files changed, 0 insertions, 357 deletions
diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c deleted file mode 100644 index d48d8e5460ff..000000000000 --- a/drivers/hwmon/sbrmi.c +++ /dev/null @@ -1,357 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * sbrmi.c - hwmon driver for a SB-RMI mailbox - * compliant AMD SoC device. - * - * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. - */ - -#include <linux/delay.h> -#include <linux/err.h> -#include <linux/hwmon.h> -#include <linux/i2c.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/mutex.h> -#include <linux/of.h> - -/* Do not allow setting negative power limit */ -#define SBRMI_PWR_MIN 0 -/* Mask for Status Register bit[1] */ -#define SW_ALERT_MASK 0x2 - -/* Software Interrupt for triggering */ -#define START_CMD 0x80 -#define TRIGGER_MAILBOX 0x01 - -/* - * SB-RMI supports soft mailbox service request to MP1 (power management - * firmware) through SBRMI inbound/outbound message registers. - * SB-RMI message IDs - */ -enum sbrmi_msg_id { - SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, - SBRMI_WRITE_PKG_PWR_LIMIT, - SBRMI_READ_PKG_PWR_LIMIT, - SBRMI_READ_PKG_MAX_PWR_LIMIT, -}; - -/* SB-RMI registers */ -enum sbrmi_reg { - SBRMI_CTRL = 0x01, - SBRMI_STATUS, - SBRMI_OUTBNDMSG0 = 0x30, - SBRMI_OUTBNDMSG1, - SBRMI_OUTBNDMSG2, - SBRMI_OUTBNDMSG3, - SBRMI_OUTBNDMSG4, - SBRMI_OUTBNDMSG5, - SBRMI_OUTBNDMSG6, - SBRMI_OUTBNDMSG7, - SBRMI_INBNDMSG0, - SBRMI_INBNDMSG1, - SBRMI_INBNDMSG2, - SBRMI_INBNDMSG3, - SBRMI_INBNDMSG4, - SBRMI_INBNDMSG5, - SBRMI_INBNDMSG6, - SBRMI_INBNDMSG7, - SBRMI_SW_INTERRUPT, -}; - -/* Each client has this additional data */ -struct sbrmi_data { - struct i2c_client *client; - struct mutex lock; - u32 pwr_limit_max; -}; - -struct sbrmi_mailbox_msg { - u8 cmd; - bool read; - u32 data_in; - u32 data_out; -}; - -static int sbrmi_enable_alert(struct i2c_client *client) -{ - int ctrl; - - /* - * Enable the SB-RMI Software alert status - * by writing 0 to bit 4 of Control register(0x1) - */ - ctrl = i2c_smbus_read_byte_data(client, SBRMI_CTRL); - if (ctrl < 0) - return ctrl; - - if (ctrl & 0x10) { - ctrl &= ~0x10; - return i2c_smbus_write_byte_data(client, - SBRMI_CTRL, ctrl); - } - - return 0; -} - -static int rmi_mailbox_xfer(struct sbrmi_data *data, - struct sbrmi_mailbox_msg *msg) -{ - int i, ret, retry = 10; - int sw_status; - u8 byte; - - mutex_lock(&data->lock); - - /* Indicate firmware a command is to be serviced */ - ret = i2c_smbus_write_byte_data(data->client, - SBRMI_INBNDMSG7, START_CMD); - if (ret < 0) - goto exit_unlock; - - /* Write the command to SBRMI::InBndMsg_inst0 */ - ret = i2c_smbus_write_byte_data(data->client, - SBRMI_INBNDMSG0, msg->cmd); - if (ret < 0) - goto exit_unlock; - - /* - * For both read and write the initiator (BMC) writes - * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] - * SBRMI_x3C(MSB):SBRMI_x39(LSB) - */ - for (i = 0; i < 4; i++) { - byte = (msg->data_in >> i * 8) & 0xff; - ret = i2c_smbus_write_byte_data(data->client, - SBRMI_INBNDMSG1 + i, byte); - if (ret < 0) - goto exit_unlock; - } - - /* - * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to - * perform the requested read or write command - */ - ret = i2c_smbus_write_byte_data(data->client, - SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); - if (ret < 0) - goto exit_unlock; - - /* - * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate - * an ALERT (if enabled) to initiator (BMC) to indicate completion - * of the requested command - */ - do { - sw_status = i2c_smbus_read_byte_data(data->client, - SBRMI_STATUS); - if (sw_status < 0) { - ret = sw_status; - goto exit_unlock; - } - if (sw_status & SW_ALERT_MASK) - break; - usleep_range(50, 100); - } while (retry--); - - if (retry < 0) { - dev_err(&data->client->dev, - "Firmware fail to indicate command completion\n"); - ret = -EIO; - goto exit_unlock; - } - - /* - * For a read operation, the initiator (BMC) reads the firmware - * response Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] - * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. - */ - if (msg->read) { - for (i = 0; i < 4; i++) { - ret = i2c_smbus_read_byte_data(data->client, - SBRMI_OUTBNDMSG1 + i); - if (ret < 0) - goto exit_unlock; - msg->data_out |= ret << i * 8; - } - } - - /* - * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the - * ALERT to initiator - */ - ret = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, - sw_status | SW_ALERT_MASK); - -exit_unlock: - mutex_unlock(&data->lock); - return ret; -} - -static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, - u32 attr, int channel, long *val) -{ - struct sbrmi_data *data = dev_get_drvdata(dev); - struct sbrmi_mailbox_msg msg = { 0 }; - int ret; - - if (type != hwmon_power) - return -EINVAL; - - msg.read = true; - switch (attr) { - case hwmon_power_input: - msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; - ret = rmi_mailbox_xfer(data, &msg); - break; - case hwmon_power_cap: - msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; - ret = rmi_mailbox_xfer(data, &msg); - break; - case hwmon_power_cap_max: - msg.data_out = data->pwr_limit_max; - ret = 0; - break; - default: - return -EINVAL; - } - if (ret < 0) - return ret; - /* hwmon power attributes are in microWatt */ - *val = (long)msg.data_out * 1000; - return ret; -} - -static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, - u32 attr, int channel, long val) -{ - struct sbrmi_data *data = dev_get_drvdata(dev); - struct sbrmi_mailbox_msg msg = { 0 }; - - if (type != hwmon_power && attr != hwmon_power_cap) - return -EINVAL; - /* - * hwmon power attributes are in microWatt - * mailbox read/write is in mWatt - */ - val /= 1000; - - val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max); - - msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; - msg.data_in = val; - msg.read = false; - - return rmi_mailbox_xfer(data, &msg); -} - -static umode_t sbrmi_is_visible(const void *data, - enum hwmon_sensor_types type, - u32 attr, int channel) -{ - switch (type) { - case hwmon_power: - switch (attr) { - case hwmon_power_input: - case hwmon_power_cap_max: - return 0444; - case hwmon_power_cap: - return 0644; - } - break; - default: - break; - } - return 0; -} - -static const struct hwmon_channel_info * const sbrmi_info[] = { - HWMON_CHANNEL_INFO(power, - HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), - NULL -}; - -static const struct hwmon_ops sbrmi_hwmon_ops = { - .is_visible = sbrmi_is_visible, - .read = sbrmi_read, - .write = sbrmi_write, -}; - -static const struct hwmon_chip_info sbrmi_chip_info = { - .ops = &sbrmi_hwmon_ops, - .info = sbrmi_info, -}; - -static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data) -{ - struct sbrmi_mailbox_msg msg = { 0 }; - int ret; - - msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; - msg.read = true; - ret = rmi_mailbox_xfer(data, &msg); - if (ret < 0) - return ret; - data->pwr_limit_max = msg.data_out; - - return ret; -} - -static int sbrmi_probe(struct i2c_client *client) -{ - struct device *dev = &client->dev; - struct device *hwmon_dev; - struct sbrmi_data *data; - int ret; - - data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); - if (!data) - return -ENOMEM; - - data->client = client; - mutex_init(&data->lock); - - /* Enable alert for SB-RMI sequence */ - ret = sbrmi_enable_alert(client); - if (ret < 0) - return ret; - - /* Cache maximum power limit */ - ret = sbrmi_get_max_pwr_limit(data); - if (ret < 0) - return ret; - - hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, - &sbrmi_chip_info, NULL); - - return PTR_ERR_OR_ZERO(hwmon_dev); -} - -static const struct i2c_device_id sbrmi_id[] = { - {"sbrmi"}, - {} -}; -MODULE_DEVICE_TABLE(i2c, sbrmi_id); - -static const struct of_device_id __maybe_unused sbrmi_of_match[] = { - { - .compatible = "amd,sbrmi", - }, - { }, -}; -MODULE_DEVICE_TABLE(of, sbrmi_of_match); - -static struct i2c_driver sbrmi_driver = { - .driver = { - .name = "sbrmi", - .of_match_table = of_match_ptr(sbrmi_of_match), - }, - .probe = sbrmi_probe, - .id_table = sbrmi_id, -}; - -module_i2c_driver(sbrmi_driver); - -MODULE_AUTHOR("Akshay Gupta <akshay.gupta@amd.com>"); -MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); -MODULE_LICENSE("GPL"); |