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>
12 #include <linux/i2c-smbus.h>
21 	struct work_struct	alert;  member
22 	struct i2c_client	*ara;		/* Alert response address */
39 	if (!client || client->addr != data->addr)  in smbus_do_alert()
41 	if (client->flags & I2C_CLIENT_TEN)  in smbus_do_alert()
49 	if (client->dev.driver) {  in smbus_do_alert()
50 		driver = to_i2c_driver(client->dev.driver);  in smbus_do_alert()
51 		if (driver->alert) {  in smbus_do_alert()
53 			driver->alert(client, data->type, data->data);  in smbus_do_alert()
54 			ret = -EBUSY;  in smbus_do_alert()
56 			dev_warn(&client->dev, "no driver alert()!\n");  in smbus_do_alert()
57 			ret = -EOPNOTSUPP;  in smbus_do_alert()
60 		dev_dbg(&client->dev, "alert with no driver\n");  in smbus_do_alert()
61 		ret = -ENODEV;  in smbus_do_alert()
68 /* Same as above, but call back all drivers with alert handler */
76 	if (!client || (client->flags & I2C_CLIENT_TEN))  in smbus_do_alert_force()
84 	if (client->dev.driver) {  in smbus_do_alert_force()
85 		driver = to_i2c_driver(client->dev.driver);  in smbus_do_alert_force()
86 		if (driver->alert)  in smbus_do_alert_force()
87 			driver->alert(client, data->type, data->data);  in smbus_do_alert_force()
95  * The alert IRQ handler needs to hand work off to a task which can issue
100 	struct i2c_smbus_alert *alert = d;  in smbus_alert()  local
104 	ara = alert->ara;  in smbus_alert()
115 		 * Note that SMBus 2.0 reserves 10-bit addresses for future  in smbus_alert()
126 		dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",  in smbus_alert()
129 		/* Notify driver for the device which issued the alert */  in smbus_alert()
130 		status = device_for_each_child(&ara->adapter->dev, &data,  in smbus_alert()
133 		 * If we read the same address more than once, and the alert  in smbus_alert()
136 		 * time calling the alert handlers of all devices connected to  in smbus_alert()
140 		 * Note: This assumes that a driver with alert handler handles  in smbus_alert()
141 		 * the alert properly and clears it if necessary.  in smbus_alert()
143 		if (data.addr == prev_addr && status != -EBUSY) {  in smbus_alert()
144 			device_for_each_child(&ara->adapter->dev, &data,  in smbus_alert()
156 	struct i2c_smbus_alert *alert;  in smbalert_work()  local
158 	alert = container_of(work, struct i2c_smbus_alert, alert);  in smbalert_work()
160 	smbus_alert(0, alert);  in smbalert_work()
167 	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);  in smbalert_probe()
168 	struct i2c_smbus_alert *alert;  in smbalert_probe()  local
169 	struct i2c_adapter *adapter = ara->adapter;  in smbalert_probe()
172 	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),  in smbalert_probe()
174 	if (!alert)  in smbalert_probe()
175 		return -ENOMEM;  in smbalert_probe()
178 		irq = setup->irq;  in smbalert_probe()
180 		irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent),  in smbalert_probe()
186 	INIT_WORK(&alert->alert, smbalert_work);  in smbalert_probe()
187 	alert->ara = ara;  in smbalert_probe()
190 		res = devm_request_threaded_irq(&ara->dev, irq,  in smbalert_probe()
193 						"smbus_alert", alert);  in smbalert_probe()
198 	i2c_set_clientdata(ara, alert);  in smbalert_probe()
199 	dev_info(&adapter->dev, "supports SMBALERT#\n");  in smbalert_probe()
207 	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);  in smbalert_remove()  local
209 	cancel_work_sync(&alert->alert);  in smbalert_remove()
228  * i2c_handle_smbus_alert - Handle an SMBus alert
233  * handler. It will schedule the alert work, in turn calling the
234  * corresponding I2C device driver's alert function.
241 	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);  in i2c_handle_smbus_alert()  local
243 	return schedule_work(&alert->alert);  in i2c_handle_smbus_alert()
259 	struct i2c_slave_host_notify_status *status = client->dev.platform_data;  in i2c_slave_host_notify_cb()
267 		if (status->index == 0)  in i2c_slave_host_notify_cb()
268 			status->addr = *val;  in i2c_slave_host_notify_cb()
269 		if (status->index < U8_MAX)  in i2c_slave_host_notify_cb()
270 			status->index++;  in i2c_slave_host_notify_cb()
273 		if (status->index == SMBUS_HOST_NOTIFY_LEN)  in i2c_slave_host_notify_cb()
274 			i2c_handle_smbus_host_notify(client->adapter,  in i2c_slave_host_notify_cb()
275 						     status->addr);  in i2c_slave_host_notify_cb()
278 		status->index = 0;  in i2c_slave_host_notify_cb()
290  * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support
294  * Setup handling of the SMBus host-notify protocol on a given I2C bus segment.
297  * received via the SMBus host-notify address (0x8)
315 		return ERR_PTR(-ENOMEM);  in i2c_new_slave_host_notify_device()
337  * i2c_free_slave_host_notify_device - free the client for SMBus host-notify
350 	kfree(client->dev.platform_data);  in i2c_free_slave_host_notify_device()
360  *  - Only works if all filled slots have the same memory type
361  *  - Only works for DDR2, DDR3 and DDR4 for now
362  *  - Only works on systems with 1 to 4 memory slots
392 				dev_warn(&adap->dev,  in i2c_register_spd()
404 	dev_info(&adap->dev, "%d/%d memory slots populated (from DMI)\n",  in i2c_register_spd()
408 		dev_warn(&adap->dev,  in i2c_register_spd()
431 		dev_info(&adap->dev,  in i2c_register_spd()
453 			dev_info(&adap->dev,  in i2c_register_spd()
456 			dimm_count--;  in i2c_register_spd()