Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * i2c-smbus.c - SMBus extensions to the I2C protocol
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2008 David Brownell
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Copyright (C) 2010-2019 Jean Delvare <jdelvare@suse.de>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/dmi.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/i2c-smbus.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/of_irq.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/workqueue.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) struct i2c_smbus_alert {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 	struct work_struct	alert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) 	struct i2c_client	*ara;		/* Alert response address */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) struct alert_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	unsigned short		addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	enum i2c_alert_protocol	type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	unsigned int		data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /* If this is the alerting device, notify its driver */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) static int smbus_do_alert(struct device *dev, void *addrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	struct i2c_client *client = i2c_verify_client(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	struct alert_data *data = addrp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct i2c_driver *driver;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 	if (!client || client->addr != data->addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	if (client->flags & I2C_CLIENT_TEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	 * Drivers should either disable alerts, or provide at least
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	 * a minimal handler.  Lock so the driver won't change.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	device_lock(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	if (client->dev.driver) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		driver = to_i2c_driver(client->dev.driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		if (driver->alert)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 			driver->alert(client, data->type, data->data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 			dev_warn(&client->dev, "no driver alert()!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		dev_dbg(&client->dev, "alert with no driver\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	device_unlock(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	/* Stop iterating after we find the device */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63)  * The alert IRQ handler needs to hand work off to a task which can issue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64)  * SMBus calls, because those sleeping calls can't be made in IRQ context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) static irqreturn_t smbus_alert(int irq, void *d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	struct i2c_smbus_alert *alert = d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	struct i2c_client *ara;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	ara = alert->ara;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 		s32 status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		struct alert_data data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		 * Devices with pending alerts reply in address order, low
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		 * to high, because of slave transmit arbitration.  After
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		 * responding, an SMBus device stops asserting SMBALERT#.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 		 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		 * Note that SMBus 2.0 reserves 10-bit addresses for future
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		 * use.  We neither handle them, nor try to use PEC here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		status = i2c_smbus_read_byte(ara);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		if (status < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		data.data = status & 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		data.addr = status >> 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		data.type = I2C_PROTOCOL_SMBUS_ALERT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 			data.addr, data.data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		/* Notify driver for the device which issued the alert */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		device_for_each_child(&ara->adapter->dev, &data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 				      smbus_do_alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	return IRQ_HANDLED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) static void smbalert_work(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	struct i2c_smbus_alert *alert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	alert = container_of(work, struct i2c_smbus_alert, alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	smbus_alert(0, alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) /* Setup SMBALERT# infrastructure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) static int smbalert_probe(struct i2c_client *ara,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			  const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	struct i2c_smbus_alert *alert;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	struct i2c_adapter *adapter = ara->adapter;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	int res, irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 			     GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	if (!alert)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	if (setup) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		irq = setup->irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 		irq = of_irq_get_byname(adapter->dev.of_node, "smbus_alert");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 		if (irq <= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 			return irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	INIT_WORK(&alert->alert, smbalert_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	alert->ara = ara;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	if (irq > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		res = devm_request_threaded_irq(&ara->dev, irq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 						NULL, smbus_alert,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 						IRQF_SHARED | IRQF_ONESHOT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 						"smbus_alert", alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		if (res)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	i2c_set_clientdata(ara, alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	dev_info(&adapter->dev, "supports SMBALERT#\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) /* IRQ and memory resources are managed so they are freed automatically */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static int smbalert_remove(struct i2c_client *ara)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	cancel_work_sync(&alert->alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) static const struct i2c_device_id smbalert_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	{ "smbus_alert", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	{ /* LIST END */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) MODULE_DEVICE_TABLE(i2c, smbalert_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) static struct i2c_driver smbalert_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	.driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		.name	= "smbus_alert",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	},
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	.probe		= smbalert_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	.remove		= smbalert_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	.id_table	= smbalert_ids,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)  * i2c_handle_smbus_alert - Handle an SMBus alert
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180)  * @ara: the ARA client on the relevant adapter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)  * Context: can't sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)  * Helper function to be called from an I2C bus driver's interrupt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)  * handler. It will schedule the alert work, in turn calling the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185)  * corresponding I2C device driver's alert function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)  * It is assumed that ara is a valid i2c client previously returned by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)  * i2c_new_smbus_alert_device().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) int i2c_handle_smbus_alert(struct i2c_client *ara)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	return schedule_work(&alert->alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) module_i2c_driver(smbalert_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) #if IS_ENABLED(CONFIG_I2C_SLAVE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) #define SMBUS_HOST_NOTIFY_LEN	3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) struct i2c_slave_host_notify_status {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	u8 index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	u8 addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) static int i2c_slave_host_notify_cb(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 				    enum i2c_slave_event event, u8 *val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	struct i2c_slave_host_notify_status *status = client->dev.platform_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	switch (event) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	case I2C_SLAVE_WRITE_RECEIVED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 		/* We only retrieve the first byte received (addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 		 * since there is currently no support to retrieve the data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		 * parameter from the client.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		if (status->index == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 			status->addr = *val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		if (status->index < U8_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			status->index++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	case I2C_SLAVE_STOP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		if (status->index == SMBUS_HOST_NOTIFY_LEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 			i2c_handle_smbus_host_notify(client->adapter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 						     status->addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	case I2C_SLAVE_WRITE_REQUESTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		status->index = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	case I2C_SLAVE_READ_REQUESTED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	case I2C_SLAVE_READ_PROCESSED:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		*val = 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241)  * i2c_new_slave_host_notify_device - get a client for SMBus host-notify support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)  * @adapter: the target adapter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)  * Context: can sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)  * Setup handling of the SMBus host-notify protocol on a given I2C bus segment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)  * Handling is done by creating a device and its callback and handling data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)  * received via the SMBus host-notify address (0x8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)  * This returns the client, which should be ultimately freed using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)  * i2c_free_slave_host_notify_device(); or an ERRPTR to indicate an error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) struct i2c_client *i2c_new_slave_host_notify_device(struct i2c_adapter *adapter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	struct i2c_board_info host_notify_board_info = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 		I2C_BOARD_INFO("smbus_host_notify", 0x08),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 		.flags  = I2C_CLIENT_SLAVE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	struct i2c_slave_host_notify_status *status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	struct i2c_client *client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	status = kzalloc(sizeof(struct i2c_slave_host_notify_status),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 			 GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	if (!status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	host_notify_board_info.platform_data = status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	client = i2c_new_client_device(adapter, &host_notify_board_info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	if (IS_ERR(client)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		kfree(status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		return client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	ret = i2c_slave_register(client, i2c_slave_host_notify_cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		i2c_unregister_device(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 		kfree(status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	return client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) EXPORT_SYMBOL_GPL(i2c_new_slave_host_notify_device);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)  * i2c_free_slave_host_notify_device - free the client for SMBus host-notify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289)  * support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)  * @client: the client to free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)  * Context: can sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)  * Free the i2c_client allocated via i2c_new_slave_host_notify_device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) void i2c_free_slave_host_notify_device(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	if (IS_ERR_OR_NULL(client))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	i2c_slave_unregister(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 	kfree(client->dev.platform_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 	i2c_unregister_device(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)  * SPD is not part of SMBus but we include it here for convenience as the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309)  * target systems are the same.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)  * Restrictions to automatic SPD instantiation:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)  *  - Only works if all filled slots have the same memory type
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)  *  - Only works for DDR2, DDR3 and DDR4 for now
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313)  *  - Only works on systems with 1 to 4 memory slots
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) #if IS_ENABLED(CONFIG_DMI)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) void i2c_register_spd(struct i2c_adapter *adap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 	int n, slot_count = 0, dimm_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	u16 handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 	u8 common_mem_type = 0x0, mem_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	u64 mem_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 	const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	while ((handle = dmi_memdev_handle(slot_count)) != 0xffff) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 		slot_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 		/* Skip empty slots */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		mem_size = dmi_memdev_size(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 		if (!mem_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 		/* Skip undefined memory type */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 		mem_type = dmi_memdev_type(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 		if (mem_type <= 0x02)		/* Invalid, Other, Unknown */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 			continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 		if (!common_mem_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 			/* First filled slot */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 			common_mem_type = mem_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 			/* Check that all filled slots have the same type */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 			if (mem_type != common_mem_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 				dev_warn(&adap->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 					 "Different memory types mixed, not instantiating SPD\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 				return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 		dimm_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 	/* No useful DMI data, bail out */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	if (!dimm_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	dev_info(&adap->dev, "%d/%d memory slots populated (from DMI)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 		 dimm_count, slot_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	if (slot_count > 4) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 		dev_warn(&adap->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 			 "Systems with more than 4 memory slots not supported yet, not instantiating SPD\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	switch (common_mem_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 	case 0x13:	/* DDR2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	case 0x18:	/* DDR3 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	case 0x1C:	/* LPDDR2 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 	case 0x1D:	/* LPDDR3 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 		name = "spd";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) 	case 0x1A:	/* DDR4 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 	case 0x1E:	/* LPDDR4 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) 		name = "ee1004";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 		dev_info(&adap->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 			 "Memory type 0x%02x not supported yet, not instantiating SPD\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 			 common_mem_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 	 * We don't know in which slots the memory modules are. We could
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 	 * try to guess from the slot names, but that would be rather complex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 	 * and unreliable, so better probe all possible addresses until we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 	 * have found all memory modules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 	for (n = 0; n < slot_count && dimm_count; n++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 		struct i2c_board_info info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 		unsigned short addr_list[2];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) 		memset(&info, 0, sizeof(struct i2c_board_info));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 		strlcpy(info.type, name, I2C_NAME_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) 		addr_list[0] = 0x50 + n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 		addr_list[1] = I2C_CLIENT_END;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 		if (!IS_ERR(i2c_new_scanned_device(adap, &info, addr_list, NULL))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) 			dev_info(&adap->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 				 "Successfully instantiated SPD at 0x%hx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 				 addr_list[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 			dimm_count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) EXPORT_SYMBOL_GPL(i2c_register_spd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) MODULE_DESCRIPTION("SMBus protocol extensions support");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) MODULE_LICENSE("GPL");