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, 132 insertions, 0 deletions

diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c
new file mode 100644
index 000000000..4335811e0
--- /dev/null
+++ b/drivers/reset/reset-scmi.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM System Control and Management Interface (ARM SCMI) reset driver
+ *
+ * Copyright (C) 2019-2021 ARM Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/device.h>
+#include <linux/reset-controller.h>
+#include <linux/scmi_protocol.h>
+
+static const struct scmi_reset_proto_ops *reset_ops;
+
+/**
+ * struct scmi_reset_data - reset controller information structure
+ * @rcdev: reset controller entity
+ * @ph: ARM SCMI protocol handle used for communication with system controller
+ */
+struct scmi_reset_data {
+	struct reset_controller_dev rcdev;
+	const struct scmi_protocol_handle *ph;
+};
+
+#define to_scmi_reset_data(p)	container_of((p), struct scmi_reset_data, rcdev)
+#define to_scmi_handle(p)	(to_scmi_reset_data(p)->ph)
+
+/**
+ * scmi_reset_assert() - assert device reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to be asserted
+ *
+ * This function implements the reset driver op to assert a device's reset
+ * using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
+
+	return reset_ops->assert(ph, id);
+}
+
+/**
+ * scmi_reset_deassert() - deassert device reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to be deasserted
+ *
+ * This function implements the reset driver op to deassert a device's reset
+ * using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
+
+	return reset_ops->deassert(ph, id);
+}
+
+/**
+ * scmi_reset_reset() - reset the device
+ * @rcdev: reset controller entity
+ * @id: ID of the reset signal to be reset(assert + deassert)
+ *
+ * This function implements the reset driver op to trigger a device's
+ * reset signal using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
+
+	return reset_ops->reset(ph, id);
+}
+
+static const struct reset_control_ops scmi_reset_ops = {
+	.assert		= scmi_reset_assert,
+	.deassert	= scmi_reset_deassert,
+	.reset		= scmi_reset_reset,
+};
+
+static int scmi_reset_probe(struct scmi_device *sdev)
+{
+	struct scmi_reset_data *data;
+	struct device *dev = &sdev->dev;
+	struct device_node *np = dev->of_node;
+	const struct scmi_handle *handle = sdev->handle;
+	struct scmi_protocol_handle *ph;
+
+	if (!handle)
+		return -ENODEV;
+
+	reset_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_RESET, &ph);
+	if (IS_ERR(reset_ops))
+		return PTR_ERR(reset_ops);
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->rcdev.ops = &scmi_reset_ops;
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.of_node = np;
+	data->rcdev.nr_resets = reset_ops->num_domains_get(ph);
+	data->ph = ph;
+
+	return devm_reset_controller_register(dev, &data->rcdev);
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_RESET, "reset" },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_reset_driver = {
+	.name = "scmi-reset",
+	.probe = scmi_reset_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_reset_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI reset controller driver");
+MODULE_LICENSE("GPL v2");