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, 290 insertions, 0 deletions

diff --git a/drivers/i2c/i2c-slave-testunit.c b/drivers/i2c/i2c-slave-testunit.c
new file mode 100644
index 000000000..4a1bf1aa5
--- /dev/null
+++ b/drivers/i2c/i2c-slave-testunit.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C slave mode testunit
+ *
+ * Copyright (C) 2020 by Wolfram Sang, Sang Engineering <wsa@sang-engineering.com>
+ * Copyright (C) 2020 by Renesas Electronics Corporation
+ */
+
+#include <generated/utsrelease.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define TU_VERSION_MAX_LENGTH 128
+
+enum testunit_cmds {
+	TU_CMD_READ_BYTES = 1,	/* save 0 for ABORT, RESET or similar */
+	TU_CMD_SMBUS_HOST_NOTIFY,
+	TU_CMD_SMBUS_BLOCK_PROC_CALL,
+	TU_CMD_GET_VERSION_WITH_REP_START,
+	TU_CMD_SMBUS_ALERT_REQUEST,
+	TU_NUM_CMDS
+};
+
+enum testunit_regs {
+	TU_REG_CMD,
+	TU_REG_DATAL,
+	TU_REG_DATAH,
+	TU_REG_DELAY,
+	TU_NUM_REGS
+};
+
+enum testunit_flags {
+	TU_FLAG_IN_PROCESS,
+	TU_FLAG_NACK,
+};
+
+struct testunit_data {
+	unsigned long flags;
+	u8 regs[TU_NUM_REGS];
+	u8 reg_idx;
+	u8 read_idx;
+	struct i2c_client *client;
+	struct delayed_work worker;
+	struct gpio_desc *gpio;
+	struct completion alert_done;
+};
+
+static char tu_version_info[] = "v" UTS_RELEASE "\n\0";
+
+static int i2c_slave_testunit_smbalert_cb(struct i2c_client *client,
+					  enum i2c_slave_event event, u8 *val)
+{
+	struct testunit_data *tu = i2c_get_clientdata(client);
+
+	switch (event) {
+	case I2C_SLAVE_READ_PROCESSED:
+		gpiod_set_value(tu->gpio, 0);
+		fallthrough;
+	case I2C_SLAVE_READ_REQUESTED:
+		*val = tu->regs[TU_REG_DATAL];
+		break;
+
+	case I2C_SLAVE_STOP:
+		complete(&tu->alert_done);
+		break;
+
+	case I2C_SLAVE_WRITE_REQUESTED:
+	case I2C_SLAVE_WRITE_RECEIVED:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int i2c_slave_testunit_slave_cb(struct i2c_client *client,
+				     enum i2c_slave_event event, u8 *val)
+{
+	struct testunit_data *tu = i2c_get_clientdata(client);
+	bool is_proc_call = tu->reg_idx == 3 && tu->regs[TU_REG_DATAL] == 1 &&
+			    tu->regs[TU_REG_CMD] == TU_CMD_SMBUS_BLOCK_PROC_CALL;
+	bool is_get_version = tu->reg_idx == 3 &&
+			      tu->regs[TU_REG_CMD] == TU_CMD_GET_VERSION_WITH_REP_START;
+	int ret = 0;
+
+	switch (event) {
+	case I2C_SLAVE_WRITE_REQUESTED:
+		if (test_bit(TU_FLAG_IN_PROCESS | TU_FLAG_NACK, &tu->flags)) {
+			ret = -EBUSY;
+			break;
+		}
+
+		memset(tu->regs, 0, TU_NUM_REGS);
+		tu->reg_idx = 0;
+		tu->read_idx = 0;
+		break;
+
+	case I2C_SLAVE_WRITE_RECEIVED:
+		if (test_bit(TU_FLAG_IN_PROCESS | TU_FLAG_NACK, &tu->flags)) {
+			ret = -EBUSY;
+			break;
+		}
+
+		if (tu->reg_idx < TU_NUM_REGS)
+			tu->regs[tu->reg_idx] = *val;
+		else
+			ret = -EMSGSIZE;
+
+		if (tu->reg_idx <= TU_NUM_REGS)
+			tu->reg_idx++;
+
+		/* TU_REG_CMD always written at this point */
+		if (tu->regs[TU_REG_CMD] >= TU_NUM_CMDS)
+			ret = -EINVAL;
+
+		break;
+
+	case I2C_SLAVE_STOP:
+		if (tu->reg_idx == TU_NUM_REGS) {
+			set_bit(TU_FLAG_IN_PROCESS, &tu->flags);
+			queue_delayed_work(system_dfl_long_wq, &tu->worker,
+					   msecs_to_jiffies(10 * tu->regs[TU_REG_DELAY]));
+		}
+
+		/*
+		 * Reset reg_idx to avoid that work gets queued again in case of
+		 * STOP after a following read message. But do not clear TU regs
+		 * here because we still need them in the workqueue!
+		 */
+		tu->reg_idx = 0;
+
+		clear_bit(TU_FLAG_NACK, &tu->flags);
+		break;
+
+	case I2C_SLAVE_READ_PROCESSED:
+		/* Advance until we reach the NUL character */
+		if (is_get_version && tu_version_info[tu->read_idx] != 0)
+			tu->read_idx++;
+		else if (is_proc_call && tu->regs[TU_REG_DATAH])
+			tu->regs[TU_REG_DATAH]--;
+
+		fallthrough;
+
+	case I2C_SLAVE_READ_REQUESTED:
+		if (is_get_version)
+			*val = tu_version_info[tu->read_idx];
+		else if (is_proc_call)
+			*val = tu->regs[TU_REG_DATAH];
+		else
+			*val = test_bit(TU_FLAG_IN_PROCESS, &tu->flags) ?
+					tu->regs[TU_REG_CMD] : 0;
+		break;
+	}
+
+	/* If an error occurred somewhen, we NACK everything until next STOP */
+	if (ret)
+		set_bit(TU_FLAG_NACK, &tu->flags);
+
+	return ret;
+}
+
+static void i2c_slave_testunit_work(struct work_struct *work)
+{
+	struct testunit_data *tu = container_of(work, struct testunit_data, worker.work);
+	unsigned long time_left;
+	struct i2c_msg msg;
+	u8 msgbuf[256];
+	u16 orig_addr;
+	int ret = 0;
+
+	msg.addr = I2C_CLIENT_END;
+	msg.buf = msgbuf;
+
+	switch (tu->regs[TU_REG_CMD]) {
+	case TU_CMD_READ_BYTES:
+		msg.addr = tu->regs[TU_REG_DATAL];
+		msg.flags = I2C_M_RD;
+		msg.len = tu->regs[TU_REG_DATAH];
+		break;
+
+	case TU_CMD_SMBUS_HOST_NOTIFY:
+		msg.addr = 0x08;
+		msg.flags = 0;
+		msg.len = 3;
+		msgbuf[0] = tu->client->addr;
+		msgbuf[1] = tu->regs[TU_REG_DATAL];
+		msgbuf[2] = tu->regs[TU_REG_DATAH];
+		break;
+
+	case TU_CMD_SMBUS_ALERT_REQUEST:
+		if (!tu->gpio) {
+			ret = -ENOENT;
+			break;
+		}
+		i2c_slave_unregister(tu->client);
+		orig_addr = tu->client->addr;
+		tu->client->addr = 0x0c;
+		ret = i2c_slave_register(tu->client, i2c_slave_testunit_smbalert_cb);
+		if (ret)
+			goto out_smbalert;
+
+		reinit_completion(&tu->alert_done);
+		gpiod_set_value(tu->gpio, 1);
+		time_left = wait_for_completion_timeout(&tu->alert_done, HZ);
+		if (!time_left)
+			ret = -ETIMEDOUT;
+
+		i2c_slave_unregister(tu->client);
+out_smbalert:
+		tu->client->addr = orig_addr;
+		i2c_slave_register(tu->client, i2c_slave_testunit_slave_cb);
+		break;
+
+	default:
+		break;
+	}
+
+	if (msg.addr != I2C_CLIENT_END) {
+		ret = i2c_transfer(tu->client->adapter, &msg, 1);
+		/* convert '0 msgs transferred' to errno */
+		ret = (ret == 0) ? -EIO : ret;
+	}
+
+	if (ret < 0)
+		dev_err(&tu->client->dev, "CMD%02X failed (%d)\n", tu->regs[TU_REG_CMD], ret);
+
+	clear_bit(TU_FLAG_IN_PROCESS, &tu->flags);
+}
+
+static int i2c_slave_testunit_probe(struct i2c_client *client)
+{
+	struct testunit_data *tu;
+
+	tu = devm_kzalloc(&client->dev, sizeof(struct testunit_data), GFP_KERNEL);
+	if (!tu)
+		return -ENOMEM;
+
+	tu->client = client;
+	i2c_set_clientdata(client, tu);
+	init_completion(&tu->alert_done);
+	INIT_DELAYED_WORK(&tu->worker, i2c_slave_testunit_work);
+
+	tu->gpio = devm_gpiod_get_index_optional(&client->dev, NULL, 0, GPIOD_OUT_LOW);
+	if (IS_ERR(tu->gpio))
+		return PTR_ERR(tu->gpio);
+
+	if (gpiod_cansleep(tu->gpio)) {
+		dev_err(&client->dev, "GPIO access which may sleep is not allowed\n");
+		return -EDEADLK;
+	}
+
+	if (sizeof(tu_version_info) > TU_VERSION_MAX_LENGTH)
+		tu_version_info[TU_VERSION_MAX_LENGTH - 1] = 0;
+
+	return i2c_slave_register(client, i2c_slave_testunit_slave_cb);
+};
+
+static void i2c_slave_testunit_remove(struct i2c_client *client)
+{
+	struct testunit_data *tu = i2c_get_clientdata(client);
+
+	cancel_delayed_work_sync(&tu->worker);
+	i2c_slave_unregister(client);
+}
+
+static const struct i2c_device_id i2c_slave_testunit_id[] = {
+	{ .name = "slave-testunit" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, i2c_slave_testunit_id);
+
+static struct i2c_driver i2c_slave_testunit_driver = {
+	.driver = {
+		.name = "i2c-slave-testunit",
+	},
+	.probe = i2c_slave_testunit_probe,
+	.remove = i2c_slave_testunit_remove,
+	.id_table = i2c_slave_testunit_id,
+};
+module_i2c_driver(i2c_slave_testunit_driver);
+
+MODULE_AUTHOR("Wolfram Sang <wsa@sang-engineering.com>");
+MODULE_DESCRIPTION("I2C slave mode test unit");
+MODULE_LICENSE("GPL v2");