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, 204 insertions, 0 deletions

diff --git a/drivers/misc/eeprom/max6875.c b/drivers/misc/eeprom/max6875.c
new file mode 100644
index 000000000..5731d2dc8
--- /dev/null
+++ b/drivers/misc/eeprom/max6875.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * max6875.c - driver for MAX6874/MAX6875
+ *
+ * Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
+ *
+ * Based on eeprom.c
+ *
+ * The MAX6875 has a bank of registers and two banks of EEPROM.
+ * Address ranges are defined as follows:
+ *  * 0x0000 - 0x0046 = configuration registers
+ *  * 0x8000 - 0x8046 = configuration EEPROM
+ *  * 0x8100 - 0x82FF = user EEPROM
+ *
+ * This driver makes the user EEPROM available for read.
+ *
+ * The registers & config EEPROM should be accessed via i2c-dev.
+ *
+ * The MAX6875 ignores the lowest address bit, so each chip responds to
+ * two addresses - 0x50/0x51 and 0x52/0x53.
+ *
+ * Note that the MAX6875 uses i2c_smbus_write_byte_data() to set the read
+ * address, so this driver is destructive if loaded for the wrong EEPROM chip.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+
+/* The MAX6875 can only read/write 16 bytes at a time */
+#define SLICE_SIZE			16
+#define SLICE_BITS			4
+
+/* USER EEPROM is at addresses 0x8100 - 0x82FF */
+#define USER_EEPROM_BASE		0x8100
+#define USER_EEPROM_SIZE		0x0200
+#define USER_EEPROM_SLICES		32
+
+/* MAX6875 commands */
+#define MAX6875_CMD_BLK_READ		0x84
+
+/* Each client has this additional data */
+struct max6875_data {
+	struct i2c_client	*fake_client;
+	struct mutex		update_lock;
+
+	u32			valid;
+	u8			data[USER_EEPROM_SIZE];
+	unsigned long		last_updated[USER_EEPROM_SLICES];
+};
+
+static void max6875_update_slice(struct i2c_client *client, int slice)
+{
+	struct max6875_data *data = i2c_get_clientdata(client);
+	int i, j, addr;
+	u8 *buf;
+
+	if (slice >= USER_EEPROM_SLICES)
+		return;
+
+	mutex_lock(&data->update_lock);
+
+	buf = &data->data[slice << SLICE_BITS];
+
+	if (!(data->valid & (1 << slice)) ||
+	    time_after(jiffies, data->last_updated[slice])) {
+
+		dev_dbg(&client->dev, "Starting update of slice %u\n", slice);
+
+		data->valid &= ~(1 << slice);
+
+		addr = USER_EEPROM_BASE + (slice << SLICE_BITS);
+
+		/* select the eeprom address */
+		if (i2c_smbus_write_byte_data(client, addr >> 8, addr & 0xFF)) {
+			dev_err(&client->dev, "address set failed\n");
+			goto exit_up;
+		}
+
+		if (i2c_check_functionality(client->adapter,
+					    I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
+			if (i2c_smbus_read_i2c_block_data(client,
+							  MAX6875_CMD_BLK_READ,
+							  SLICE_SIZE,
+							  buf) != SLICE_SIZE) {
+				goto exit_up;
+			}
+		} else {
+			for (i = 0; i < SLICE_SIZE; i++) {
+				j = i2c_smbus_read_byte(client);
+				if (j < 0) {
+					goto exit_up;
+				}
+				buf[i] = j;
+			}
+		}
+		data->last_updated[slice] = jiffies;
+		data->valid |= (1 << slice);
+	}
+exit_up:
+	mutex_unlock(&data->update_lock);
+}
+
+static ssize_t max6875_read(struct file *filp, struct kobject *kobj,
+			    const struct bin_attribute *bin_attr,
+			    char *buf, loff_t off, size_t count)
+{
+	struct i2c_client *client = kobj_to_i2c_client(kobj);
+	struct max6875_data *data = i2c_get_clientdata(client);
+	int slice, max_slice;
+
+	/* refresh slices which contain requested bytes */
+	max_slice = (off + count - 1) >> SLICE_BITS;
+	for (slice = (off >> SLICE_BITS); slice <= max_slice; slice++)
+		max6875_update_slice(client, slice);
+
+	memcpy(buf, &data->data[off], count);
+
+	return count;
+}
+
+static const struct bin_attribute user_eeprom_attr = {
+	.attr = {
+		.name = "eeprom",
+		.mode = S_IRUGO,
+	},
+	.size = USER_EEPROM_SIZE,
+	.read = max6875_read,
+};
+
+static int max6875_probe(struct i2c_client *client)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct max6875_data *data;
+	int err;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA
+				     | I2C_FUNC_SMBUS_READ_BYTE))
+		return -ENODEV;
+
+	/* Only bind to even addresses */
+	if (client->addr & 1)
+		return -ENODEV;
+
+	data = kzalloc_obj(struct max6875_data);
+	if (!data)
+		return -ENOMEM;
+
+	/* A fake client is created on the odd address */
+	data->fake_client = i2c_new_dummy_device(client->adapter, client->addr + 1);
+	if (IS_ERR(data->fake_client)) {
+		err = PTR_ERR(data->fake_client);
+		goto exit_kfree;
+	}
+
+	/* Init real i2c_client */
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->update_lock);
+
+	err = sysfs_create_bin_file(&client->dev.kobj, &user_eeprom_attr);
+	if (err)
+		goto exit_remove_fake;
+
+	return 0;
+
+exit_remove_fake:
+	i2c_unregister_device(data->fake_client);
+exit_kfree:
+	kfree(data);
+	return err;
+}
+
+static void max6875_remove(struct i2c_client *client)
+{
+	struct max6875_data *data = i2c_get_clientdata(client);
+
+	i2c_unregister_device(data->fake_client);
+
+	sysfs_remove_bin_file(&client->dev.kobj, &user_eeprom_attr);
+	kfree(data);
+}
+
+static const struct i2c_device_id max6875_id[] = {
+	{ "max6875" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max6875_id);
+
+static struct i2c_driver max6875_driver = {
+	.driver = {
+		.name	= "max6875",
+	},
+	.probe		= max6875_probe,
+	.remove		= max6875_remove,
+	.id_table	= max6875_id,
+};
+
+module_i2c_driver(max6875_driver);
+
+MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
+MODULE_DESCRIPTION("MAX6875 driver");
+MODULE_LICENSE("GPL");