Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 218 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c
new file mode 100644
index 000000000..226d722af
--- /dev/null
+++ b/drivers/i2c/i2c-slave-eeprom.c
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C slave mode EEPROM simulator
+ *
+ * Copyright (C) 2014 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ * Copyright (C) 2014 by Renesas Electronics Corporation
+ *
+ * Because most slave IP cores can only detect one I2C slave address anyhow,
+ * this driver does not support simulating EEPROM types which take more than
+ * one address.
+ */
+
+/*
+ * FIXME: What to do if only 8 bits of a 16 bit address are sent?
+ * The ST-M24C64 sends only 0xff then. Needs verification with other
+ * EEPROMs, though. We currently use the 8 bit as a valid address.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/firmware.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/sysfs.h>
+
+struct eeprom_data {
+	struct bin_attribute bin;
+	spinlock_t buffer_lock;
+	u16 buffer_idx;
+	u16 address_mask;
+	u8 num_address_bytes;
+	u8 idx_write_cnt;
+	bool read_only;
+	u8 buffer[];
+};
+
+#define I2C_SLAVE_BYTELEN GENMASK(15, 0)
+#define I2C_SLAVE_FLAG_ADDR16 BIT(16)
+#define I2C_SLAVE_FLAG_RO BIT(17)
+#define I2C_SLAVE_DEVICE_MAGIC(_len, _flags) ((_flags) | ((_len) - 1))
+
+static int i2c_slave_eeprom_slave_cb(struct i2c_client *client,
+				     enum i2c_slave_event event, u8 *val)
+{
+	struct eeprom_data *eeprom = i2c_get_clientdata(client);
+
+	switch (event) {
+	case I2C_SLAVE_WRITE_RECEIVED:
+		if (eeprom->idx_write_cnt < eeprom->num_address_bytes) {
+			if (eeprom->idx_write_cnt == 0)
+				eeprom->buffer_idx = 0;
+			eeprom->buffer_idx = *val | (eeprom->buffer_idx << 8);
+			eeprom->idx_write_cnt++;
+		} else {
+			if (!eeprom->read_only) {
+				spin_lock(&eeprom->buffer_lock);
+				eeprom->buffer[eeprom->buffer_idx++ & eeprom->address_mask] = *val;
+				spin_unlock(&eeprom->buffer_lock);
+			}
+		}
+		break;
+
+	case I2C_SLAVE_READ_PROCESSED:
+		/* The previous byte made it to the bus, get next one */
+		eeprom->buffer_idx++;
+		fallthrough;
+	case I2C_SLAVE_READ_REQUESTED:
+		spin_lock(&eeprom->buffer_lock);
+		*val = eeprom->buffer[eeprom->buffer_idx & eeprom->address_mask];
+		spin_unlock(&eeprom->buffer_lock);
+		/*
+		 * Do not increment buffer_idx here, because we don't know if
+		 * this byte will be actually used. Read Linux I2C slave docs
+		 * for details.
+		 */
+		break;
+
+	case I2C_SLAVE_STOP:
+	case I2C_SLAVE_WRITE_REQUESTED:
+		eeprom->idx_write_cnt = 0;
+		break;
+
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static ssize_t i2c_slave_eeprom_bin_read(struct file *filp, struct kobject *kobj,
+		const struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct eeprom_data *eeprom;
+	unsigned long flags;
+
+	eeprom = dev_get_drvdata(kobj_to_dev(kobj));
+
+	spin_lock_irqsave(&eeprom->buffer_lock, flags);
+	memcpy(buf, &eeprom->buffer[off], count);
+	spin_unlock_irqrestore(&eeprom->buffer_lock, flags);
+
+	return count;
+}
+
+static ssize_t i2c_slave_eeprom_bin_write(struct file *filp, struct kobject *kobj,
+		const struct bin_attribute *attr, char *buf, loff_t off, size_t count)
+{
+	struct eeprom_data *eeprom;
+	unsigned long flags;
+
+	eeprom = dev_get_drvdata(kobj_to_dev(kobj));
+
+	spin_lock_irqsave(&eeprom->buffer_lock, flags);
+	memcpy(&eeprom->buffer[off], buf, count);
+	spin_unlock_irqrestore(&eeprom->buffer_lock, flags);
+
+	return count;
+}
+
+static int i2c_slave_init_eeprom_data(struct eeprom_data *eeprom, struct i2c_client *client,
+				      unsigned int size)
+{
+	const struct firmware *fw;
+	const char *eeprom_data;
+	int ret = device_property_read_string(&client->dev, "firmware-name", &eeprom_data);
+
+	if (!ret) {
+		ret = request_firmware_into_buf(&fw, eeprom_data, &client->dev,
+						eeprom->buffer, size);
+		if (ret)
+			return ret;
+		release_firmware(fw);
+	} else {
+		/* An empty eeprom typically has all bits set to 1 */
+		memset(eeprom->buffer, 0xff, size);
+	}
+	return 0;
+}
+
+static int i2c_slave_eeprom_probe(struct i2c_client *client)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	struct eeprom_data *eeprom;
+	int ret;
+	unsigned int size = FIELD_GET(I2C_SLAVE_BYTELEN, id->driver_data) + 1;
+	unsigned int flag_addr16 = FIELD_GET(I2C_SLAVE_FLAG_ADDR16, id->driver_data);
+
+	eeprom = devm_kzalloc(&client->dev, sizeof(struct eeprom_data) + size, GFP_KERNEL);
+	if (!eeprom)
+		return -ENOMEM;
+
+	eeprom->num_address_bytes = flag_addr16 ? 2 : 1;
+	eeprom->address_mask = size - 1;
+	eeprom->read_only = FIELD_GET(I2C_SLAVE_FLAG_RO, id->driver_data);
+	spin_lock_init(&eeprom->buffer_lock);
+	i2c_set_clientdata(client, eeprom);
+
+	ret = i2c_slave_init_eeprom_data(eeprom, client, size);
+	if (ret)
+		return ret;
+
+	sysfs_bin_attr_init(&eeprom->bin);
+	eeprom->bin.attr.name = "slave-eeprom";
+	eeprom->bin.attr.mode = S_IRUSR | S_IWUSR;
+	eeprom->bin.read = i2c_slave_eeprom_bin_read;
+	eeprom->bin.write = i2c_slave_eeprom_bin_write;
+	eeprom->bin.size = size;
+
+	ret = sysfs_create_bin_file(&client->dev.kobj, &eeprom->bin);
+	if (ret)
+		return ret;
+
+	ret = i2c_slave_register(client, i2c_slave_eeprom_slave_cb);
+	if (ret) {
+		sysfs_remove_bin_file(&client->dev.kobj, &eeprom->bin);
+		return ret;
+	}
+
+	return 0;
+};
+
+static void i2c_slave_eeprom_remove(struct i2c_client *client)
+{
+	struct eeprom_data *eeprom = i2c_get_clientdata(client);
+
+	i2c_slave_unregister(client);
+	sysfs_remove_bin_file(&client->dev.kobj, &eeprom->bin);
+}
+
+static const struct i2c_device_id i2c_slave_eeprom_id[] = {
+	{ .name = "slave-24c02", .driver_data = I2C_SLAVE_DEVICE_MAGIC(2048 / 8,  0) },
+	{ .name = "slave-24c02ro", .driver_data = I2C_SLAVE_DEVICE_MAGIC(2048 / 8,  I2C_SLAVE_FLAG_RO) },
+	{ .name = "slave-24c32", .driver_data = I2C_SLAVE_DEVICE_MAGIC(32768 / 8, I2C_SLAVE_FLAG_ADDR16) },
+	{ .name = "slave-24c32ro", .driver_data = I2C_SLAVE_DEVICE_MAGIC(32768 / 8, I2C_SLAVE_FLAG_ADDR16 | I2C_SLAVE_FLAG_RO) },
+	{ .name = "slave-24c64", .driver_data = I2C_SLAVE_DEVICE_MAGIC(65536 / 8, I2C_SLAVE_FLAG_ADDR16) },
+	{ .name = "slave-24c64ro", .driver_data = I2C_SLAVE_DEVICE_MAGIC(65536 / 8, I2C_SLAVE_FLAG_ADDR16 | I2C_SLAVE_FLAG_RO) },
+	{ .name = "slave-24c512", .driver_data = I2C_SLAVE_DEVICE_MAGIC(524288 / 8, I2C_SLAVE_FLAG_ADDR16) },
+	{ .name = "slave-24c512ro", .driver_data = I2C_SLAVE_DEVICE_MAGIC(524288 / 8, I2C_SLAVE_FLAG_ADDR16 | I2C_SLAVE_FLAG_RO) },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_slave_eeprom_id);
+
+static struct i2c_driver i2c_slave_eeprom_driver = {
+	.driver = {
+		.name = "i2c-slave-eeprom",
+	},
+	.probe = i2c_slave_eeprom_probe,
+	.remove = i2c_slave_eeprom_remove,
+	.id_table = i2c_slave_eeprom_id,
+};
+module_i2c_driver(i2c_slave_eeprom_driver);
+
+MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
+MODULE_DESCRIPTION("I2C slave mode EEPROM simulator");
+MODULE_LICENSE("GPL v2");