1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * i2c-smbus.c - SMBus extensions to the I2C protocol
6  * Copyright (C) 2010-2019 Jean Delvare <jdelvare@suse.de>
13 #include <linux/i2c-smbus.h>
40 	if (!client || client->addr != data->addr)  in smbus_do_alert()
42 	if (client->flags & I2C_CLIENT_TEN)  in smbus_do_alert()
50 	if (client->dev.driver) {  in smbus_do_alert()
51 		driver = to_i2c_driver(client->dev.driver);  in smbus_do_alert()
52 		if (driver->alert) {  in smbus_do_alert()
54 			driver->alert(client, data->type, data->data);  in smbus_do_alert()
55 			ret = -EBUSY;  in smbus_do_alert()
57 			dev_warn(&client->dev, "no driver alert()!\n");  in smbus_do_alert()
58 			ret = -EOPNOTSUPP;  in smbus_do_alert()
61 		dev_dbg(&client->dev, "alert with no driver\n");  in smbus_do_alert()
62 		ret = -ENODEV;  in smbus_do_alert()
77 	if (!client || (client->flags & I2C_CLIENT_TEN))  in smbus_do_alert_force()
85 	if (client->dev.driver) {  in smbus_do_alert_force()
86 		driver = to_i2c_driver(client->dev.driver);  in smbus_do_alert_force()
87 		if (driver->alert)  in smbus_do_alert_force()
88 			driver->alert(client, data->type, data->data);  in smbus_do_alert_force()
105 	ara = alert->ara;  in smbus_alert()
114 		 * responding, an SMBus device stops asserting SMBALERT#.  in smbus_alert()
116 		 * Note that SMBus 2.0 reserves 10-bit addresses for future  in smbus_alert()
127 		dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",  in smbus_alert()
131 		status = device_for_each_child(&ara->adapter->dev, &data,  in smbus_alert()
144 		if (data.addr == prev_addr && status != -EBUSY) {  in smbus_alert()
145 			device_for_each_child(&ara->adapter->dev, &data,  in smbus_alert()
168 	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);  in smbalert_probe()
170 	struct i2c_adapter *adapter = ara->adapter;  in smbalert_probe()
175 	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),  in smbalert_probe()
178 		return -ENOMEM;  in smbalert_probe()
181 		irq = setup->irq;  in smbalert_probe()
183 		irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent),  in smbalert_probe()
186 			gpiod = devm_gpiod_get(adapter->dev.parent, "smbalert", GPIOD_IN);  in smbalert_probe()
198 	INIT_WORK(&alert->alert, smbalert_work);  in smbalert_probe()
199 	alert->ara = ara;  in smbalert_probe()
202 		res = devm_request_threaded_irq(&ara->dev, irq, NULL, smbus_alert,  in smbalert_probe()
209 	dev_info(&adapter->dev, "supports SMBALERT#\n");  in smbalert_probe()
219 	cancel_work_sync(&alert->alert);  in smbalert_remove()
238  * i2c_handle_smbus_alert - Handle an SMBus alert
253 	return schedule_work(&alert->alert);  in i2c_handle_smbus_alert()
269 	struct i2c_slave_host_notify_status *status = client->dev.platform_data;  in i2c_slave_host_notify_cb()
277 		if (status->index == 0)  in i2c_slave_host_notify_cb()
278 			status->addr = *val;  in i2c_slave_host_notify_cb()
279 		if (status->index < U8_MAX)  in i2c_slave_host_notify_cb()
280 			status->index++;  in i2c_slave_host_notify_cb()
283 		if (status->index == SMBUS_HOST_NOTIFY_LEN)  in i2c_slave_host_notify_cb()
284 			i2c_handle_smbus_host_notify(client->adapter,  in i2c_slave_host_notify_cb()
285 						     status->addr);  in i2c_slave_host_notify_cb()
288 		status->index = 0;  in i2c_slave_host_notify_cb()
300  * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support
304  * Setup handling of the SMBus host-notify protocol on a given I2C bus segment.
307  * received via the SMBus host-notify address (0x8)
325 		return ERR_PTR(-ENOMEM);  in i2c_new_slave_host_notify_device()
347  * i2c_free_slave_host_notify_device - free the client for SMBus host-notify
360 	kfree(client->dev.platform_data);  in i2c_free_slave_host_notify_device()
370  *  - Only works if all filled slots have the same memory type
371  *  - Only works for (LP)DDR memory types up to DDR5
372  *  - Only works on systems with 1 to 8 memory slots
402 				dev_warn(&adap->dev,  in i2c_register_spd()
443 		dev_info(&adap->dev,  in i2c_register_spd()
465 			dev_info(&adap->dev,  in i2c_register_spd()
468 			dimm_count--;  in i2c_register_spd()
475 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");