1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * sbrmi.c - hwmon driver for a SB-RMI mailbox
6  * Copyright (C) 2020-2021 Advanced Micro Devices, Inc.
28  * SB-RMI supports soft mailbox service request to MP1 (power management
30  * SB-RMI message IDs
39 /* SB-RMI registers */
81 	 * Enable the SB-RMI Software alert status  in sbrmi_enable_alert()
104 	mutex_lock(&data->lock);  in rmi_mailbox_xfer()
107 	ret = i2c_smbus_write_byte_data(data->client,  in rmi_mailbox_xfer()
113 	ret = i2c_smbus_write_byte_data(data->client,  in rmi_mailbox_xfer()
114 					SBRMI_INBNDMSG0, msg->cmd);  in rmi_mailbox_xfer()
124 		byte = (msg->data_in >> i * 8) & 0xff;  in rmi_mailbox_xfer()
125 		ret = i2c_smbus_write_byte_data(data->client,  in rmi_mailbox_xfer()
135 	ret = i2c_smbus_write_byte_data(data->client,  in rmi_mailbox_xfer()
146 		sw_status = i2c_smbus_read_byte_data(data->client,  in rmi_mailbox_xfer()
155 	} while (retry--);  in rmi_mailbox_xfer()
158 		dev_err(&data->client->dev,  in rmi_mailbox_xfer()
160 		ret = -EIO;  in rmi_mailbox_xfer()
169 	if (msg->read) {  in rmi_mailbox_xfer()
171 			ret = i2c_smbus_read_byte_data(data->client,  in rmi_mailbox_xfer()
175 			msg->data_out |= ret << i * 8;  in rmi_mailbox_xfer()
183 	ret = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS,  in rmi_mailbox_xfer()
187 	mutex_unlock(&data->lock);  in rmi_mailbox_xfer()
199 		return -EINVAL;  in sbrmi_read()
212 		msg.data_out = data->pwr_limit_max;  in sbrmi_read()
216 		return -EINVAL;  in sbrmi_read()
232 		return -EINVAL;  in sbrmi_write()
239 	val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max);  in sbrmi_write()
295 	data->pwr_limit_max = msg.data_out;  in sbrmi_get_max_pwr_limit()
302 	struct device *dev = &client->dev;  in sbrmi_probe()
309 		return -ENOMEM;  in sbrmi_probe()
311 	data->client = client;  in sbrmi_probe()
312 	mutex_init(&data->lock);  in sbrmi_probe()
314 	/* Enable alert for SB-RMI sequence */  in sbrmi_probe()
324 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,  in sbrmi_probe()
356 MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor");