i3c/master: introduce the mipi-i3c-hci driver

This adds basic support for hardware implementing the MIPI I3C HCI
specification. This driver is currently limited by the capabilities
of the I3C subsystem, meaning things like scheduled commands,
auto-commands and NCM mode are not yet supported.

This supports version 1.0 of the MIPI I3C HCI spec, as well as the
imminent release of version 1.1. Support for draft version 2.0 of the
spec is also largely included with the caveat that future adjustments
to this code are likely as the spec is still a work in progress.

This is also lightly tested as actual hardware is still very scarce,
even for HCI v1.0. Hence the EXPERIMENTAL tag. Further contributions
to this driver are expected once vendor implementations and new I3C
devices become available.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-i3c/20201111220510.3622216-3-nico@fluxnic.net

18 files changed, 4264 insertions, 0 deletions

diff --git a/drivers/i3c/master/Kconfig b/drivers/i3c/master/Kconfig
index 4e80a1fcbf91..e68f15f4b4d0 100644
--- a/drivers/i3c/master/Kconfig
+++ b/drivers/i3c/master/Kconfig
@@ -21,3 +21,16 @@ config DW_I3C_MASTER
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called dw-i3c-master.
+
+config MIPI_I3C_HCI
+	tristate "MIPI I3C Host Controller Interface driver (EXPERIMENTAL)"
+	depends on I3C
+	help
+	  Support for hardware following the MIPI Aliance's I3C Host Controller
+	  Interface specification.
+
+	  For details please see:
+	  https://www.mipi.org/specifications/i3c-hci
+
+	  This driver can also be built as a module.  If so, the module will be
+	  called mipi-i3c-hci.
diff --git a/drivers/i3c/master/Makefile b/drivers/i3c/master/Makefile
index 7eea9e086144..b892fd4cafad 100644
--- a/drivers/i3c/master/Makefile
+++ b/drivers/i3c/master/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_CDNS_I3C_MASTER)		+= i3c-master-cdns.o
 obj-$(CONFIG_DW_I3C_MASTER)		+= dw-i3c-master.o
+obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci/
diff --git a/drivers/i3c/master/mipi-i3c-hci/Makefile b/drivers/i3c/master/mipi-i3c-hci/Makefile
new file mode 100644
index 000000000000..a658e7b8262c
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci.o
+mipi-i3c-hci-y				:= core.o ext_caps.o pio.o dma.o \
+					   cmd_v1.o cmd_v2.o \
+					   dat_v1.o dct_v1.o
diff --git a/drivers/i3c/master/mipi-i3c-hci/cmd.h b/drivers/i3c/master/mipi-i3c-hci/cmd.h
new file mode 100644
index 000000000000..1d6dd2c5d01a
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/cmd.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (c) 2020, MIPI Alliance, Inc.
+ *
+ * Author: Nicolas Pitre <npitre@baylibre.com>
+ *
+ * Common command/response related stuff
+ */
+
+#ifndef CMD_H
+#define CMD_H
+
+/*
+ * Those bits are common to all descriptor formats and
+ * may be manipulated by the core code.
+ */
+#define CMD_0_TOC			W0_BIT_(31)
+#define CMD_0_ROC			W0_BIT_(30)
+#define CMD_0_ATTR			W0_MASK(2, 0)
+
+/*
+ * Response Descriptor Structure
+ */
+#define RESP_STATUS(resp)		FIELD_GET(GENMASK(31, 28), resp)
+#define RESP_TID(resp)			FIELD_GET(GENMASK(27, 24), resp)
+#define RESP_DATA_LENGTH(resp)		FIELD_GET(GENMASK(21,  0), resp)
+
+#define RESP_ERR_FIELD			GENMASK(31, 28)
+
+enum hci_resp_err {
+	RESP_SUCCESS			= 0x0,
+	RESP_ERR_CRC			= 0x1,
+	RESP_ERR_PARITY			= 0x2,
+	RESP_ERR_FRAME			= 0x3,
+	RESP_ERR_ADDR_HEADER		= 0x4,
+	RESP_ERR_BCAST_NACK_7E		= 0x4,
+	RESP_ERR_NACK			= 0x5,
+	RESP_ERR_OVL			= 0x6,
+	RESP_ERR_I3C_SHORT_READ		= 0x7,
+	RESP_ERR_HC_TERMINATED		= 0x8,
+	RESP_ERR_I2C_WR_DATA_NACK	= 0x9,
+	RESP_ERR_BUS_XFER_ABORTED	= 0x9,
+	RESP_ERR_NOT_SUPPORTED		= 0xa,
+	RESP_ERR_ABORTED_WITH_CRC	= 0xb,
+	/* 0xc to 0xf are reserved for transfer specific errors */
+};
+
+/* TID generation (4 bits wide in all cases) */
+#define hci_get_tid(bits) \
+	(atomic_inc_return_relaxed(&hci->next_cmd_tid) % (1U << 4))
+
+/* This abstracts operations with our command descriptor formats */
+struct hci_cmd_ops {
+	int (*prep_ccc)(struct i3c_hci *hci, struct hci_xfer *xfer,
+			u8 ccc_addr, u8 ccc_cmd, bool raw);
+	void (*prep_i3c_xfer)(struct i3c_hci *hci, struct i3c_dev_desc *dev,
+			      struct hci_xfer *xfer);
+	void (*prep_i2c_xfer)(struct i3c_hci *hci, struct i2c_dev_desc *dev,
+			      struct hci_xfer *xfer);
+	int (*perform_daa)(struct i3c_hci *hci);
+};
+
+/* Our various instances */
+extern const struct hci_cmd_ops mipi_i3c_hci_cmd_v1;
+extern const struct hci_cmd_ops mipi_i3c_hci_cmd_v2;
+
+#endif
diff --git a/drivers/i3c/master/mipi-i3c-hci/cmd_v1.c b/drivers/i3c/master/mipi-i3c-hci/cmd_v1.c
new file mode 100644
index 000000000000..6dd234a82892
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/cmd_v1.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2020, MIPI Alliance, Inc.
+ *
+ * Author: Nicolas Pitre <npitre@baylibre.com>
+ *
+ * I3C HCI v1.0/v1.1 Command Descriptor Handling
+ */
+
+#include <linux/bitfield.h>
+#include <linux/i3c/master.h>
+
+#include "hci.h"
+#include "cmd.h"
+#include "dat.h"
+#include "dct.h"
+
+
+/*
+ * Address Assignment Command
+ */
+
+#define CMD_0_ATTR_A			FIELD_PREP(CMD_0_ATTR, 0x2)
+
+#define CMD_A0_TOC				   W0_BIT_(31)
+#define CMD_A0_ROC				   W0_BIT_(30)
+#define CMD_A0_DEV_COUNT(v)		FIELD_PREP(W0_MASK(29, 26), v)
+#define CMD_A0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
+#define CMD_A0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
+#define CMD_A0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
+
+/*
+ * Immediate Data Transfer Command
+ */
+
+#define CMD_0_ATTR_I			FIELD_PREP(CMD_0_ATTR, 0x1)
+
+#define CMD_I1_DATA_BYTE_4(v)		FIELD_PREP(W1_MASK(63, 56), v)
+#define CMD_I1_DATA_BYTE_3(v)		FIELD_PREP(W1_MASK(55, 48), v)
+#define CMD_I1_DATA_BYTE_2(v)		FIELD_PREP(W1_MASK(47, 40), v)
+#define CMD_I1_DATA_BYTE_1(v)		FIELD_PREP(W1_MASK(39, 32), v)
+#define CMD_I1_DEF_BYTE(v)		FIELD_PREP(W1_MASK(39, 32), v)
+#define CMD_I0_TOC				   W0_BIT_(31)
+#define CMD_I0_ROC				   W0_BIT_(30)
+#define CMD_I0_RNW				   W0_BIT_(29)
+#define CMD_I0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
+#define CMD_I0_DTT(v)			FIELD_PREP(W0_MASK(25, 23), v)
+#define CMD_I0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
+#define CMD_I0_CP				   W0_BIT_(15)
+#define CMD_I0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
+#define CMD_I0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
+
+/*
+ * Regular Data Transfer Command
+ */
+
+#define CMD_0_ATTR_R			FIELD_PREP(CMD_0_ATTR, 0x0)
+
+#define CMD_R1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK(63, 48), v)
+#define CMD_R1_DEF_BYTE(v)		FIELD_PREP(W1_MASK(39, 32), v)
+#define CMD_R0_TOC				   W0_BIT_(31)
+#define CMD_R0_ROC				   W0_BIT_(30)
+#define CMD_R0_RNW				   W0_BIT_(29)
+#define CMD_R0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
+#define CMD_R0_DBP				   W0_BIT_(25)
+#define CMD_R0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
+#define CMD_R0_CP				   W0_BIT_(15)
+#define CMD_R0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
+#define CMD_R0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
+
+/*
+ * Combo Transfer (Write + Write/Read) Command
+ */
+
+#define CMD_0_ATTR_C			FIELD_PREP(CMD_0_ATTR, 0x3)
+
+#define CMD_C1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK(63, 48), v)
+#define CMD_C1_OFFSET(v)		FIELD_PREP(W1_MASK(47, 32), v)
+#define CMD_C0_TOC				   W0_BIT_(31)
+#define CMD_C0_ROC				   W0_BIT_(30)
+#define CMD_C0_RNW				   W0_BIT_(29)
+#define CMD_C0_MODE(v)			FIELD_PREP(W0_MASK(28, 26), v)
+#define CMD_C0_16_BIT_SUBOFFSET			   W0_BIT_(25)
+#define CMD_C0_FIRST_PHASE_MODE			   W0_BIT_(24)
+#define CMD_C0_DATA_LENGTH_POSITION(v)	FIELD_PREP(W0_MASK(23, 22), v)
+#define CMD_C0_DEV_INDEX(v)		FIELD_PREP(W0_MASK(20, 16), v)
+#define CMD_C0_CP				   W0_BIT_(15)
+#define CMD_C0_CMD(v)			FIELD_PREP(W0_MASK(14,  7), v)
+#define CMD_C0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
+
+/*
+ * Internal Control Command
+ */
+
+#define CMD_0_ATTR_M			FIELD_PREP(CMD_0_ATTR, 0x7)
+
+#define CMD_M1_VENDOR_SPECIFIC			   W1_MASK(63, 32)
+#define CMD_M0_MIPI_RESERVED			   W0_MASK(31, 12)
+#define CMD_M0_MIPI_CMD				   W0_MASK(11,  8)
+#define CMD_M0_VENDOR_INFO_PRESENT		   W0_BIT_( 7)
+#define CMD_M0_TID(v)			FIELD_PREP(W0_MASK( 6,  3), v)
+
+
+/* Data Transfer Speed and Mode */
+enum hci_cmd_mode {
+	MODE_I3C_SDR0		= 0x0,
+	MODE_I3C_SDR1		= 0x1,
+	MODE_I3C_SDR2		= 0x2,
+	MODE_I3C_SDR3		= 0x3,
+	MODE_I3C_SDR4		= 0x4,
+	MODE_I3C_HDR_TSx	= 0x5,
+	MODE_I3C_HDR_DDR	= 0x6,
+	MODE_I3C_HDR_BT		= 0x7,
+	MODE_I3C_Fm_FmP		= 0x8,
+	MODE_I2C_Fm		= 0x0,
+	MODE_I2C_FmP		= 0x1,
+	MODE_I2C_UD1		= 0x2,
+	MODE_I2C_UD2		= 0x3,
+	MODE_I2C_UD3		= 0x4,
+};
+
+static enum hci_cmd_mode get_i3c_mode(struct i3c_hci *hci)
+{
+	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
+
+	if (bus->scl_rate.i3c >= 12500000)
+		return MODE_I3C_SDR0;
+	if (bus->scl_rate.i3c > 8000000)
+		return MODE_I3C_SDR1;
+	if (bus->scl_rate.i3c > 6000000)
+		return MODE_I3C_SDR2;
+	if (bus->scl_rate.i3c > 4000000)
+		return MODE_I3C_SDR3;
+	if (bus->scl_rate.i3c > 2000000)
+		return MODE_I3C_SDR4;
+	return MODE_I3C_Fm_FmP;
+}
+
+static enum hci_cmd_mode get_i2c_mode(struct i3c_hci *hci)
+{
+	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
+
+	if (bus->scl_rate.i2c >= 1000000)
+		return MODE_I2C_FmP;
+	return MODE_I2C_Fm;
+}
+
+static void fill_data_bytes(struct hci_xfer *xfer, u8 *data,
+			    unsigned int data_len)
+{
+	xfer->cmd_desc[1] = 0;
+	switch (data_len) {
+	case 4:
+		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_4(data[3]);
+		fallthrough;
+	case 3:
+		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_3(data[2]);
+		fallthrough;
+	case 2:
+		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_2(data[1]);
+		fallthrough;
+	case 1:
+		xfer->cmd_desc[1] |= CMD_I1_DATA_BYTE_1(data[0]);
+		fallthrough;
+	case 0:
+		break;
+	}
+	/* we consumed all the data with the cmd descriptor */
+	xfer->data = NULL;
+}
+
+static int hci_cmd_v1_prep_ccc(struct i3c_hci *hci,
+			       struct hci_xfer *xfer,
+			       u8 ccc_addr, u8 ccc_cmd, bool raw)
+{
+	unsigned int dat_idx = 0;
+	enum hci_cmd_mode mode = get_i3c_mode(hci);
+	u8 *data = xfer->data;
+	unsigned int data_len = xfer->data_len;
+	bool rnw = xfer->rnw;
+	int ret;
+
+	/* this should never happen */
+	if (WARN_ON(raw))
+		return -EINVAL;
+
+	if (ccc_addr != I3C_BROADCAST_ADDR) {
+		ret = mipi_i3c_hci_dat_v1.get_index(hci, ccc_addr);
+		if (ret < 0)
+			return ret;
+		dat_idx = ret;
+	}
+
+	xfer->cmd_tid = hci_get_tid();
+
+	if (!rnw && data_len <= 4) {
+		/* we use an Immediate Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_I |
+			CMD_I0_TID(xfer->cmd_tid) |
+			CMD_I0_CMD(ccc_cmd) | CMD_I0_CP |
+			CMD_I0_DEV_INDEX(dat_idx) |
+			CMD_I0_DTT(data_len) |
+			CMD_I0_MODE(mode);
+		fill_data_bytes(xfer, data, data_len);
+	} else {
+		/* we use a Regular Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_R |
+			CMD_R0_TID(xfer->cmd_tid) |
+			CMD_R0_CMD(ccc_cmd) | CMD_R0_CP |
+			CMD_R0_DEV_INDEX(dat_idx) |
+			CMD_R0_MODE(mode) |
+			(rnw ? CMD_R0_RNW : 0);
+		xfer->cmd_desc[1] =
+			CMD_R1_DATA_LENGTH(data_len);
+	}
+
+	return 0;
+}
+
+static void hci_cmd_v1_prep_i3c_xfer(struct i3c_hci *hci,
+				     struct i3c_dev_desc *dev,
+				     struct hci_xfer *xfer)
+{
+	struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev);
+	unsigned int dat_idx = dev_data->dat_idx;
+	enum hci_cmd_mode mode = get_i3c_mode(hci);
+	u8 *data = xfer->data;
+	unsigned int data_len = xfer->data_len;
+	bool rnw = xfer->rnw;
+
+	xfer->cmd_tid = hci_get_tid();
+
+	if (!rnw && data_len <= 4) {
+		/* we use an Immediate Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_I |
+			CMD_I0_TID(xfer->cmd_tid) |
+			CMD_I0_DEV_INDEX(dat_idx) |
+			CMD_I0_DTT(data_len) |
+			CMD_I0_MODE(mode);
+		fill_data_bytes(xfer, data, data_len);
+	} else {
+		/* we use a Regular Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_R |
+			CMD_R0_TID(xfer->cmd_tid) |
+			CMD_R0_DEV_INDEX(dat_idx) |
+			CMD_R0_MODE(mode) |
+			(rnw ? CMD_R0_RNW : 0);
+		xfer->cmd_desc[1] =
+			CMD_R1_DATA_LENGTH(data_len);
+	}
+}
+
+static void hci_cmd_v1_prep_i2c_xfer(struct i3c_hci *hci,
+				     struct i2c_dev_desc *dev,
+				     struct hci_xfer *xfer)
+{
+	struct i3c_hci_dev_data *dev_data = i2c_dev_get_master_data(dev);
+	unsigned int dat_idx = dev_data->dat_idx;
+	enum hci_cmd_mode mode = get_i2c_mode(hci);
+	u8 *data = xfer->data;
+	unsigned int data_len = xfer->data_len;
+	bool rnw = xfer->rnw;
+
+	xfer->cmd_tid = hci_get_tid();
+
+	if (!rnw && data_len <= 4) {
+		/* we use an Immediate Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_I |
+			CMD_I0_TID(xfer->cmd_tid) |
+			CMD_I0_DEV_INDEX(dat_idx) |
+			CMD_I0_DTT(data_len) |
+			CMD_I0_MODE(mode);
+		fill_data_bytes(xfer, data, data_len);
+	} else {
+		/* we use a Regular Data Transfer Command */
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_R |
+			CMD_R0_TID(xfer->cmd_tid) |
+			CMD_R0_DEV_INDEX(dat_idx) |
+			CMD_R0_MODE(mode) |
+			(rnw ? CMD_R0_RNW : 0);
+		xfer->cmd_desc[1] =
+			CMD_R1_DATA_LENGTH(data_len);
+	}
+}
+
+static int hci_cmd_v1_daa(struct i3c_hci *hci)
+{
+	struct hci_xfer *xfer;
+	int ret, dat_idx = -1;
+	u8 next_addr;
+	u64 pid;
+	unsigned int dcr, bcr;
+	DECLARE_COMPLETION_ONSTACK(done);
+
+	xfer = hci_alloc_xfer(2);
+	if (!xfer)
+		return -ENOMEM;
+
+	/*
+	 * Simple for now: we allocate a temporary DAT entry, do a single
+	 * DAA, register the device which will allocate its own DAT entry
+	 * via the core callback, then free the temporary DAT entry.
+	 * Loop until there is no more devices to assign an address to.
+	 * Yes, there is room for improvements.
+	 */
+	for (;;) {
+		ret = mipi_i3c_hci_dat_v1.alloc_entry(hci);
+		if (ret < 0)
+			break;
+		dat_idx = ret;
+		ret = i3c_master_get_free_addr(&hci->master, next_addr);
+		if (ret < 0)
+			break;
+		next_addr = ret;
+
+		DBG("next_addr = 0x%02x, DAA using DAT %d", next_addr, dat_idx);
+		mipi_i3c_hci_dat_v1.set_dynamic_addr(hci, dat_idx, next_addr);
+		mipi_i3c_hci_dct_index_reset(hci);
+
+		xfer->cmd_tid = hci_get_tid();
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_A |
+			CMD_A0_TID(xfer->cmd_tid) |
+			CMD_A0_CMD(I3C_CCC_ENTDAA) |
+			CMD_A0_DEV_INDEX(dat_idx) |
+			CMD_A0_DEV_COUNT(1) |
+			CMD_A0_ROC | CMD_A0_TOC;
+		xfer->cmd_desc[1] = 0;
+		hci->io->queue_xfer(hci, xfer, 1);
+		if (!wait_for_completion_timeout(&done, HZ) &&
+		    hci->io->dequeue_xfer(hci, xfer, 1)) {
+			ret = -ETIME;
+			break;
+		}
+		if (RESP_STATUS(xfer[0].response) == RESP_ERR_NACK &&
+		    RESP_STATUS(xfer[0].response) == 1) {
+			ret = 0;  /* no more devices to be assigned */
+			break;
+		}
+		if (RESP_STATUS(xfer[0].response) != RESP_SUCCESS) {
+			ret = -EIO;
+			break;
+		}
+
+		i3c_hci_dct_get_val(hci, 0, &pid, &dcr, &bcr);
+		DBG("assigned address %#x to device PID=0x%llx DCR=%#x BCR=%#x",
+		    next_addr, pid, dcr, bcr);
+
+		mipi_i3c_hci_dat_v1.free_entry(hci, dat_idx);
+		dat_idx = -1;
+
+		/*
+		 * TODO: Extend the subsystem layer to allow for registering
+		 * new device and provide BCR/DCR/PID at the same time.
+		 */
+		ret = i3c_master_add_i3c_dev_locked(&hci->master, next_addr);
+		if (ret)
+			break;
+	}
+
+	if (dat_idx >= 0)
+		mipi_i3c_hci_dat_v1.free_entry(hci, dat_idx);
+	hci_free_xfer(xfer, 1);
+	return ret;
+}
+
+const struct hci_cmd_ops mipi_i3c_hci_cmd_v1 = {
+	.prep_ccc		= hci_cmd_v1_prep_ccc,
+	.prep_i3c_xfer		= hci_cmd_v1_prep_i3c_xfer,
+	.prep_i2c_xfer		= hci_cmd_v1_prep_i2c_xfer,
+	.perform_daa		= hci_cmd_v1_daa,
+};
diff --git a/drivers/i3c/master/mipi-i3c-hci/cmd_v2.c b/drivers/i3c/master/mipi-i3c-hci/cmd_v2.c
new file mode 100644
index 000000000000..4493b2b067cb
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/cmd_v2.c
@@ -0,0 +1,316 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2020, MIPI Alliance, Inc.
+ *
+ * Author: Nicolas Pitre <npitre@baylibre.com>
+ *
+ * I3C HCI v2.0 Command Descriptor Handling
+ *
+ * Note: The I3C HCI v2.0 spec is still in flux. The code here will change.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/i3c/master.h>
+
+#include "hci.h"
+#include "cmd.h"
+#include "xfer_mode_rate.h"
+
+
+/*
+ * Unified Data Transfer Command
+ */
+
+#define CMD_0_ATTR_U			FIELD_PREP(CMD_0_ATTR, 0x4)
+
+#define CMD_U3_HDR_TSP_ML_CTRL(v)	FIELD_PREP(W3_MASK(107, 104), v)
+#define CMD_U3_IDB4(v)			FIELD_PREP(W3_MASK(103,  96), v)
+#define CMD_U3_HDR_CMD(v)		FIELD_PREP(W3_MASK(103,  96), v)
+#define CMD_U2_IDB3(v)			FIELD_PREP(W2_MASK( 95,  88), v)
+#define CMD_U2_HDR_BT(v)		FIELD_PREP(W2_MASK( 95,  88), v)
+#define CMD_U2_IDB2(v)			FIELD_PREP(W2_MASK( 87,  80), v)
+#define CMD_U2_BT_CMD2(v)		FIELD_PREP(W2_MASK( 87,  80), v)
+#define CMD_U2_IDB1(v)			FIELD_PREP(W2_MASK( 79,  72), v)
+#define CMD_U2_BT_CMD1(v)		FIELD_PREP(W2_MASK( 79,  72), v)
+#define CMD_U2_IDB0(v)			FIELD_PREP(W2_MASK( 71,  64), v)
+#define CMD_U2_BT_CMD0(v)		FIELD_PREP(W2_MASK( 71,  64), v)
+#define CMD_U1_ERR_HANDLING(v)		FIELD_PREP(W1_MASK( 63,  62), v)
+#define CMD_U1_ADD_FUNC(v)		FIELD_PREP(W1_MASK( 61,  56), v)
+#define CMD_U1_COMBO_XFER			   W1_BIT_( 55)
+#define CMD_U1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK( 53,  32), v)
+#define CMD_U0_TOC				   W0_BIT_( 31)
+#define CMD_U0_ROC				   W0_BIT_( 30)
+#define CMD_U0_MAY_YIELD			   W0_BIT_( 29)
+#define CMD_U0_NACK_RCNT(v)		FIELD_PREP(W0_MASK( 28,  27), v)
+#define CMD_U0_IDB_COUNT(v)		FIELD_PREP(W0_MASK( 26,  24), v)
+#define CMD_U0_MODE_INDEX(v)		FIELD_PREP(W0_MASK( 22,  18), v)
+#define CMD_U0_XFER_RATE(v)		FIELD_PREP(W0_MASK( 17,  15), v)
+#define CMD_U0_DEV_ADDRESS(v)		FIELD_PREP(W0_MASK( 14,   8), v)
+#define CMD_U0_RnW				   W0_BIT_(  7)
+#define CMD_U0_TID(v)			FIELD_PREP(W0_MASK(  6,   3), v)
+
+/*
+ * Address Assignment Command
+ */
+
+#define CMD_0_ATTR_A			FIELD_PREP(CMD_0_ATTR, 0x2)
+
+#define CMD_A1_DATA_LENGTH(v)		FIELD_PREP(W1_MASK( 53,  32), v)
+#define CMD_A0_TOC				   W0_BIT_( 31)
+#define CMD_A0_ROC				   W0_BIT_( 30)
+#define CMD_A0_XFER_RATE(v)		FIELD_PREP(W0_MASK( 17,  15), v)
+#define CMD_A0_ASSIGN_ADDRESS(v)	FIELD_PREP(W0_MASK( 14,   8), v)
+#define CMD_A0_TID(v)			FIELD_PREP(W0_MASK(  6,   3), v)
+
+
+static unsigned int get_i3c_rate_idx(struct i3c_hci *hci)
+{
+	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
+
+	if (bus->scl_rate.i3c >= 12000000)
+		return XFERRATE_I3C_SDR0;
+	if (bus->scl_rate.i3c > 8000000)
+		return XFERRATE_I3C_SDR1;
+	if (bus->scl_rate.i3c > 6000000)
+		return XFERRATE_I3C_SDR2;
+	if (bus->scl_rate.i3c > 4000000)
+		return XFERRATE_I3C_SDR3;
+	if (bus->scl_rate.i3c > 2000000)
+		return XFERRATE_I3C_SDR4;
+	return XFERRATE_I3C_SDR_FM_FMP;
+}
+
+static unsigned int get_i2c_rate_idx(struct i3c_hci *hci)
+{
+	struct i3c_bus *bus = i3c_master_get_bus(&hci->master);
+
+	if (bus->scl_rate.i2c >= 1000000)
+		return XFERRATE_I2C_FMP;
+	return XFERRATE_I2C_FM;
+}
+
+static void hci_cmd_v2_prep_private_xfer(struct i3c_hci *hci,
+					 struct hci_xfer *xfer,
+					 u8 addr, unsigned int mode,
+					 unsigned int rate)
+{
+	u8 *data = xfer->data;
+	unsigned int data_len = xfer->data_len;
+	bool rnw = xfer->rnw;
+
+	xfer->cmd_tid = hci_get_tid();
+
+	if (!rnw && data_len <= 5) {
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_U |
+			CMD_U0_TID(xfer->cmd_tid) |
+			CMD_U0_DEV_ADDRESS(addr) |
+			CMD_U0_XFER_RATE(rate) |
+			CMD_U0_MODE_INDEX(mode) |
+			CMD_U0_IDB_COUNT(data_len);
+		xfer->cmd_desc[1] =
+			CMD_U1_DATA_LENGTH(0);
+		xfer->cmd_desc[2] = 0;
+		xfer->cmd_desc[3] = 0;
+		switch (data_len) {
+		case 5:
+			xfer->cmd_desc[3] |= CMD_U3_IDB4(data[4]);
+			fallthrough;
+		case 4:
+			xfer->cmd_desc[2] |= CMD_U2_IDB3(data[3]);
+			fallthrough;
+		case 3:
+			xfer->cmd_desc[2] |= CMD_U2_IDB2(data[2]);
+			fallthrough;
+		case 2:
+			xfer->cmd_desc[2] |= CMD_U2_IDB1(data[1]);
+			fallthrough;
+		case 1:
+			xfer->cmd_desc[2] |= CMD_U2_IDB0(data[0]);
+			fallthrough;
+		case 0:
+			break;
+		}
+		/* we consumed all the data with the cmd descriptor */
+		xfer->data = NULL;
+	} else {
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_U |
+			CMD_U0_TID(xfer->cmd_tid) |
+			(rnw ? CMD_U0_RnW : 0) |
+			CMD_U0_DEV_ADDRESS(addr) |
+			CMD_U0_XFER_RATE(rate) |
+			CMD_U0_MODE_INDEX(mode);
+		xfer->cmd_desc[1] =
+			CMD_U1_DATA_LENGTH(data_len);
+		xfer->cmd_desc[2] = 0;
+		xfer->cmd_desc[3] = 0;
+	}
+}
+
+static int hci_cmd_v2_prep_ccc(struct i3c_hci *hci, struct hci_xfer *xfer,
+			       u8 ccc_addr, u8 ccc_cmd, bool raw)
+{
+	unsigned int mode = XFERMODE_IDX_I3C_SDR;
+	unsigned int rate = get_i3c_rate_idx(hci);
+	u8 *data = xfer->data;
+	unsigned int data_len = xfer->data_len;
+	bool rnw = xfer->rnw;
+
+	if (raw && ccc_addr != I3C_BROADCAST_ADDR) {
+		hci_cmd_v2_prep_private_xfer(hci, xfer, ccc_addr, mode, rate);
+		return 0;
+	}
+
+	xfer->cmd_tid = hci_get_tid();
+
+	if (!rnw && data_len <= 4) {
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_U |
+			CMD_U0_TID(xfer->cmd_tid) |
+			CMD_U0_DEV_ADDRESS(ccc_addr) |
+			CMD_U0_XFER_RATE(rate) |
+			CMD_U0_MODE_INDEX(mode) |
+			CMD_U0_IDB_COUNT(data_len + (!raw ? 0 : 1));
+		xfer->cmd_desc[1] =
+			CMD_U1_DATA_LENGTH(0);
+		xfer->cmd_desc[2] =
+			CMD_U2_IDB0(ccc_cmd);
+		xfer->cmd_desc[3] = 0;
+		switch (data_len) {
+		case 4:
+			xfer->cmd_desc[3] |= CMD_U3_IDB4(data[3]);
+			fallthrough;
+		case 3:
+			xfer->cmd_desc[2] |= CMD_U2_IDB3(data[2]);
+			fallthrough;
+		case 2:
+			xfer->cmd_desc[2] |= CMD_U2_IDB2(data[1]);
+			fallthrough;
+		case 1:
+			xfer->cmd_desc[2] |= CMD_U2_IDB1(data[0]);
+			fallthrough;
+		case 0:
+			break;
+		}
+		/* we consumed all the data with the cmd descriptor */
+		xfer->data = NULL;
+	} else {
+		xfer->cmd_desc[0] =
+			CMD_0_ATTR_U |
+			CMD_U0_TID(xfer->cmd_tid) |
+			(rnw ? CMD_U0_RnW : 0) |
+			CMD_U0_DEV_ADDRESS(ccc_addr) |
+			CMD_U0_XFER_RATE(rate) |
+			CMD_U0_MODE_INDEX(mode) |
+			CMD_U0_IDB_COUNT(!raw ? 0 : 1);
+		xfer->cmd_desc[1] =
+			CMD_U1_DATA_LENGTH(data_len);
+		xfer->cmd_desc[2] =
+			CMD_U2_IDB0(ccc_cmd);
+		xfer->cmd_desc[3] = 0;
+	}
+
+	return 0;
+}
+
+static void hci_cmd_v2_prep_i3c_xfer(struct i3c_hci *hci,
+				     struct i3c_dev_desc *dev,
+				     struct hci_xfer *xfer)
+{
+	unsigned int mode = XFERMODE_IDX_I3C_SDR;
+	unsigned int rate = get_i3c_rate_idx(hci);
+	u8 addr = dev->info.dyn_addr;
+
+	hci_cmd_v2_prep_private_xfer(hci, xfer, addr, mode, rate);
+}
+
+static void hci_cmd_v2_prep_i2c_xfer(struct i3c_hci *hci,
+				     struct i2c_dev_desc *dev,
+				     struct hci_xfer *xfer)
+{
+	unsigned int mode = XFERMODE_IDX_I2C;
+	unsigned int rate = get_i2c_rate_idx(hci);
+	u8 addr = dev->addr;
+
+	hci_cmd_v2_prep_private_xfer(hci, xfer, addr, mode, rate);
+}
+
+static int hci_cmd_v2_daa(struct i3c_hci *hci)
+{
+	struct hci_xfer *xfer;
+	int ret;
+	u8 next_addr = 0;
+	u32 device_id[2];
+	u64 pid;
+	unsigned int dcr, bcr;
+	DECLARE_COMPLETION_ONSTACK(done);
+
+	xfer = hci_alloc_xfer(2);
+	if (!xfer)
+		return -ENOMEM;
+
+	xfer[0].data = &device_id;
+	xfer[0].data_len = 8;
+	xfer[0].rnw = true;
+	xfer[0].cmd_desc[1] = CMD_A1_DATA_LENGTH(8);
+	xfer[1].completion = &done;
+
+	for (;;) {
+		ret = i3c_master_get_free_addr(&hci->master, next_addr);
+		if (ret < 0)
+			break;
+		next_addr = ret;
+		DBG("next_addr = 0x%02x", next_addr);
+		xfer[0].cmd_tid = hci_get_tid();
+		xfer[0].cmd_desc[0] =
+			CMD_0_ATTR_A |
+			CMD_A0_TID(xfer[0].cmd_tid) |
+			CMD_A0_ROC;
+		xfer[1].cmd_tid = hci_get_tid();
+		xfer[1].cmd_desc[0] =
+			CMD_0_ATTR_A |
+			CMD_A0_TID(xfer[1].cmd_tid) |
+			CMD_A0_ASSIGN_ADDRESS(next_addr) |
+			CMD_A0_ROC |
+			CMD_A0_TOC;
+		hci->io->queue_xfer(hci, xfer, 2);
+		if (!wait_for_completion_timeout(&done, HZ) &&
+		    hci->io->dequeue_xfer(hci, xfer, 2)) {
+			ret = -ETIME;
+			break;
+		}
+		if (RESP_STATUS(xfer[0].response) != RESP_SUCCESS) {
+			ret = 0;  /* no more devices to be assigned */
+			break;
+		}
+		if (RESP_STATUS(xfer[1].response) != RESP_SUCCESS) {
+			ret = -EIO;
+			break;
+		}
+
+		pid = FIELD_GET(W1_MASK(47, 32), device_id[1]);
+		pid = (pid << 32) | device_id[0];
+		bcr = FIELD_GET(W1_MASK(55, 48), device_id[1]);
+		dcr = FIELD_GET(W1_MASK(63, 56), device_id[1]);
+		DBG("assigned address %#x to device PID=0x%llx DCR=%#x BCR=%#x",
+		    next_addr, pid, dcr, bcr);
+		/*
+		 * TODO: Extend the subsystem layer to allow for registering
+		 * new device and provide BCR/DCR/PID at the same time.
+		 */
+		ret = i3c_master_add_i3c_dev_locked(&hci->master, next_addr);
+		if (ret)
+			break;
+	}
+
+	hci_free_xfer(xfer, 2);
+	return ret;
+}
+
+const struct hci_cmd_ops mipi_i3c_hci_cmd_v2 = {
+	.prep_ccc		= hci_cmd_v2_prep_ccc,
+	.prep_i3c_xfer		= hci_cmd_v2_prep_i3c_xfer,
+	.prep_i2c_xfer		= hci_cmd_v2_prep_i2c_xfer,
+	.perform_daa		= hci_cmd_v2_daa,
+};
diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
new file mode 100644
index 000000000000..113c4c90546e
--- /dev/null
+++ b/drivers/i3c/master/mipi-i3c-hci/core.c
@@ -0,0 +1,798 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2020, MIPI Alliance, Inc.
+ *
+ * Author: Nicolas Pitre <npitre@baylibre.com>
+ *
+ * Core driver code with main interface to the I3C subsystem.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/i3c/master.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "hci.h"
+#include "ext_caps.h"
+#include "cmd.h"
+#include "dat.h"
+
+
+/*
+ * Host Controller Capabilities and Operation Registers
+ */
+
+#define reg_read(r)		readl(hci->base_regs + (r))
+#define reg_write(r, v)		writel(v, hci->base_regs + (r))
+#define reg_set(r, v)		reg_write(r, reg_read(r) | (v))
+#define reg_clear(r, v)		reg_write(r, reg_read(r) & ~(v))
+
+#define HCI_VERSION			0x00	/* HCI Version (in BCD) */
+
+#define HC_CONTROL			0x04
+#define HC_CONTROL_BUS_ENABLE		BIT(31)
+#define HC_CONTROL_RESUME		BIT(30)
+#define HC_CONTROL_ABORT		BIT(29)
+#define HC_CONTROL_HALT_ON_CMD_TIMEOUT	BIT(12)
+#define HC_CONTROL_HOT_JOIN_CTRL	BIT(8)	/* Hot-Join ACK/NACK Control */
+#define HC_CONTROL_I2C_TARGET_PRESENT	BIT(7)
+#define HC_CONTROL_PIO_MODE		BIT(6)	/* DMA/PIO Mode Selector */
+#define HC_CONTROL_DATA_BIG_ENDIAN	BIT(4)
+#define HC_CONTROL_IBA_INCLUDE		BIT(0)	/* Include I3C Broadcast Address */
+
+#define MASTER_DEVICE_ADDR		0x08	/* Master Device Address */
+#define MASTER_DYNAMIC_ADDR_VALID	BIT(31)	/* Dynamic Address is Valid */
+#define MASTER_DYNAMIC_ADDR(v)		FIELD_PREP(GENMASK(22, 16), v)
+
+#define HC_CAPABILITIES			0x0c
+#define HC_CAP_SG_DC_EN			BIT(30)
+#define HC_CAP_SG_IBI_EN		BIT(29)
+#define HC_CAP_SG_CR_EN			BIT(28)
+#define HC_CAP_MAX_DATA_LENGTH		GENMASK(24, 22)
+#define HC_CAP_CMD_SIZE			GENMASK(21, 20)
+#define HC_CAP_DIRECT_COMMANDS_EN	BIT(18)
+#define HC_CAP_MULTI_LANE_EN		BIT(15)
+#define HC_CAP_CMD_CCC_DEFBYTE		BIT(10)
+#define HC_CAP_HDR_BT_EN		BIT(8)
+#define HC_CAP_HDR_TS_EN		BIT(7)
+#define HC_CAP_HDR_DDR_EN		BIT(6)
+#define HC_CAP_NON_CURRENT_MASTER_CAP	BIT(5)	/* master handoff capable */
+#define HC_CAP_DATA_BYTE_CFG_EN		BIT(4)	/* endian selection possible */
+#define HC_CAP_AUTO_COMMAND		BIT(3)
+#define HC_CAP_COMBO_COMMAND		BIT(2)
+
+#define RESET_CONTROL			0x10
+#define BUS_RESET			BIT(31)
+#define BUS_RESET_TYPE			GENMASK(30, 29)
+#define IBI_QUEUE_RST			BIT(5)
+#define RX_FIFO_RST			BIT(4)
+#define TX_FIFO_RST			BIT(3)
+#define RESP_QUEUE_RST			BIT(2)
+#define CMD_QUEUE_RST			BIT(1)
+#define SOFT_RST			BIT(0)	/* Core Reset */
+
+#define PRESENT_STATE			0x14
+#define STATE_CURRENT_MASTER		BIT(2)
+
+#define INTR_STATUS			0x20
+#define INTR_STATUS_ENABLE		0x24
+#define INTR_SIGNAL_ENABLE		0x28
+#define INTR_FORCE			0x2c
+#define INTR_HC_CMD_SEQ_UFLOW_STAT	BIT(12)	/* Cmd Sequence Underflow */
+#define INTR_HC_RESET_CANCEL		BIT(11)	/* HC Cancelled Reset */
+#define INTR_HC_INTERNAL_ERR		BIT(10)	/* HC Internal Error */
+#define INTR_HC_PIO			BIT(8)	/* cascaded PIO interrupt */
+#define INTR_HC_RINGS			GENMASK(7, 0)
+
+#define DAT_SECTIO