[PATCH v2 11/14] soundwire: cdns: Add cadence library

[Vinod Koul]

Cadence IP implements SoundWire Master. Add base cadence library
initialization and interrupt handling

Signed-off-by: Hardik T Shah <hardik.t.shah@xxxxxxxxx>
Signed-off-by: Sanyog Kale <sanyog.r.kale@xxxxxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
---
 drivers/soundwire/Kconfig          |   3 +
 drivers/soundwire/Makefile         |   4 +
 drivers/soundwire/cadence_master.c | 469 +++++++++++++++++++++++++++++++++++++
 drivers/soundwire/cadence_master.h |  82 +++++++
 4 files changed, 558 insertions(+)
 create mode 100644 drivers/soundwire/cadence_master.c
 create mode 100644 drivers/soundwire/cadence_master.h

diff --git a/drivers/soundwire/Kconfig b/drivers/soundwire/Kconfig
index 57bf769d9be7..65d97ef59fbb 100644
--- a/drivers/soundwire/Kconfig
+++ b/drivers/soundwire/Kconfig
@@ -19,4 +19,7 @@ config SOUNDWIRE_BUS
 	tristate
 	select REGMAP_SOUNDWIRE
 
+config SOUNDWIRE_CADENCE
+	tristate
+
 endif
diff --git a/drivers/soundwire/Makefile b/drivers/soundwire/Makefile
index 67dc7b546258..f9a1ce3a860e 100644
--- a/drivers/soundwire/Makefile
+++ b/drivers/soundwire/Makefile
@@ -5,3 +5,7 @@
 #Bus Objs
 soundwire-bus-objs := bus_type.o bus.o slave.o mipi_disco.o sysfs.o
 obj-$(CONFIG_SOUNDWIRE_BUS) += soundwire-bus.o
+
+#Cadence Objs
+soundwire-cadence-objs := cadence_master.o
+obj-$(CONFIG_SOUNDWIRE_CADENCE) += soundwire-cadence.o
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
new file mode 100644
index 000000000000..7a9dc2fbf695
--- /dev/null
+++ b/drivers/soundwire/cadence_master.c
@@ -0,0 +1,469 @@
+/*
+ *  This file is provided under a dual BSD/GPLv2 license.  When using or
+ *  redistributing this file, you may do so under either license.
+ *
+ *  SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+ *
+ *  GPL LICENSE SUMMARY
+ *
+ *  Copyright(c) 2015-17 Intel Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of version 2 of the GNU General Public License as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  BSD LICENSE
+ *
+ *  Copyright(c) 2015-17 Intel Corporation.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in
+ *      the documentation and/or other materials provided with the
+ *      distribution.
+ *    * Neither the name of Intel Corporation nor the names of its
+ *      contributors may be used to endorse or promote products derived
+ *      from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/*
+ * Cadence SoundWire Master module
+ * Used by Master driver
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <linux/soundwire/sdw.h>
+#include "bus.h"
+#include "cadence_master.h"
+
+#define CDNS_MCP_CONFIG				0x0
+
+#define CDNS_MCP_CONFIG_MCMD_RETRY		GENMASK(27, 24)
+#define CDNS_MCP_CONFIG_MPREQ_DELAY		GENMASK(20, 16)
+#define CDNS_MCP_CONFIG_MMASTER			BIT(7)
+#define CDNS_MCP_CONFIG_BUS_REL			BIT(6)
+#define CDNS_MCP_CONFIG_SNIFFER			BIT(5)
+#define CDNS_MCP_CONFIG_SSPMOD			BIT(4)
+#define CDNS_MCP_CONFIG_CMD			BIT(3)
+#define CDNS_MCP_CONFIG_OP			GENMASK(2, 0)
+#define CDNS_MCP_CONFIG_OP_NORMAL		0
+
+#define CDNS_MCP_CONTROL			0x4
+
+#define CDNS_MCP_CONTROL_RST_DELAY		GENMASK(10, 8)
+#define CDNS_MCP_CONTROL_CMD_RST		BIT(7)
+#define CDNS_MCP_CONTROL_SOFT_RST		BIT(6)
+#define CDNS_MCP_CONTROL_SW_RST			BIT(5)
+#define CDNS_MCP_CONTROL_HW_RST			BIT(4)
+#define CDNS_MCP_CONTROL_CLK_PAUSE		BIT(3)
+#define CDNS_MCP_CONTROL_CLK_STOP_CLR		BIT(2)
+#define CDNS_MCP_CONTROL_CMD_ACCEPT		BIT(1)
+#define CDNS_MCP_CONTROL_BLOCK_WAKEUP		BIT(0)
+
+
+#define CDNS_MCP_CMDCTRL			0x8
+#define CDNS_MCP_SSPSTAT			0xC
+#define CDNS_MCP_FRAME_SHAPE			0x10
+#define CDNS_MCP_FRAME_SHAPE_INIT		0x14
+
+#define CDNS_MCP_CONFIG_UPDATE			0x18
+#define CDNS_MCP_CONFIG_UPDATE_BIT		BIT(0)
+
+#define CDNS_MCP_PHYCTRL			0x1C
+#define CDNS_MCP_SSP_CTRL0			0x20
+#define CDNS_MCP_SSP_CTRL1			0x28
+#define CDNS_MCP_CLK_CTRL0			0x30
+#define CDNS_MCP_CLK_CTRL1			0x38
+
+#define CDNS_MCP_STAT				0x40
+
+#define CDNS_MCP_STAT_ACTIVE_BANK		BIT(20)
+#define CDNS_MCP_STAT_CLK_STOP			BIT(16)
+
+#define CDNS_MCP_INTSTAT			0x44
+#define CDNS_MCP_INTMASK			0x48
+
+#define CDNS_MCP_INT_IRQ			BIT(31)
+#define CDNS_MCP_INT_WAKEUP			BIT(16)
+#define CDNS_MCP_INT_SLAVE_RSVD			BIT(15)
+#define CDNS_MCP_INT_SLAVE_ALERT		BIT(14)
+#define CDNS_MCP_INT_SLAVE_ATTACH		BIT(13)
+#define CDNS_MCP_INT_SLAVE_NATTACH		BIT(12)
+#define CDNS_MCP_INT_SLAVE_MASK			GENMASK(15, 12)
+#define CDNS_MCP_INT_DPINT			BIT(11)
+#define CDNS_MCP_INT_CTRL_CLASH			BIT(10)
+#define CDNS_MCP_INT_DATA_CLASH			BIT(9)
+#define CDNS_MCP_INT_CMD_ERR			BIT(7)
+#define CDNS_MCP_INT_RX_WL			BIT(2)
+#define CDNS_MCP_INT_TXE			BIT(1)
+
+#define CDNS_MCP_INTSET				0x4C
+
+#define CDNS_SDW_SLAVE_STAT			0x50
+#define CDNS_MCP_SLAVE_STAT_MASK		BIT(1, 0)
+
+#define CDNS_MCP_SLAVE_INTSTAT0			0x54
+#define CDNS_MCP_SLAVE_INTSTAT1			0x58
+#define CDNS_MCP_SLAVE_INTSTAT_NPRESENT		BIT(0)
+#define CDNS_MCP_SLAVE_INTSTAT_ATTACHED		BIT(1)
+#define CDNS_MCP_SLAVE_INTSTAT_ALERT		BIT(2)
+#define CDNS_MCP_SLAVE_INTSTAT_RESERVED		BIT(3)
+#define CDNS_MCP_SLAVE_STATUS_BITS		GENMASK(3, 0)
+#define CDNS_MCP_SLAVE_STATUS_NUM		4
+
+#define CDNS_MCP_SLAVE_INTMASK0			0x5C
+#define CDNS_MCP_SLAVE_INTMASK1			0x60
+
+#define CDNS_MCP_SLAVE_INTMASK0_MASK		GENMASK(30, 0)
+#define CDNS_MCP_SLAVE_INTMASK1_MASK		GENMASK(16, 0)
+
+#define CDNS_MCP_PORT_INTSTAT			0x64
+#define CDNS_MCP_PDI_STAT			0x6C
+
+#define CDNS_MCP_FIFOLEVEL			0x78
+#define CDNS_MCP_FIFOSTAT			0x7C
+#define CDNS_MCP_RX_FIFO_AVAIL			GENMASK(5, 0)
+
+#define CDNS_MCP_CMD_BASE			0x80
+#define CDNS_MCP_RESP_BASE			0x80
+#define CDNS_MCP_CMD_LEN			0x20
+#define CDNS_MCP_CMD_WORD_LEN			0x4
+
+#define CDNS_MCP_CMD_SSP_TAG			BIT(31)
+#define CDNS_MCP_CMD_COMMAND			GENMASK(30, 28)
+#define CDNS_MCP_CMD_DEV_ADDR			GENMASK(27, 24)
+#define CDNS_MCP_CMD_REG_ADDR_H			GENMASK(23, 16)
+#define CDNS_MCP_CMD_REG_ADDR_L			GENMASK(15, 8)
+#define CDNS_MCP_CMD_REG_DATA			GENMASK(7, 0)
+
+#define CDNS_MCP_CMD_READ			2
+#define CDNS_MCP_CMD_WRITE			3
+
+#define CDNS_MCP_RESP_RDATA			GENMASK(15, 8)
+#define CDNS_MCP_RESP_ACK			BIT(0)
+#define CDNS_MCP_RESP_NACK			BIT(1)
+
+#define CDNS_DP_SIZE				128
+
+#define CDNS_DPN_B0_CONFIG(n)			(0x100 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B0_CH_EN(n)			(0x104 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B0_SAMPLE_CTRL(n)		(0x108 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B0_OFFSET_CTRL(n)		(0x10C + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B0_HCTRL(n)			(0x110 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B0_ASYNC_CTRL(n)		(0x114 + CDNS_DP_SIZE * (n))
+
+#define CDNS_DPN_B1_CONFIG(n)			(0x118 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B1_CH_EN(n)			(0x11C + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B1_SAMPLE_CTRL(n)		(0x120 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B1_OFFSET_CTRL(n)		(0x124 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B1_HCTRL(n)			(0x128 + CDNS_DP_SIZE * (n))
+#define CDNS_DPN_B1_ASYNC_CTRL(n)		(0x12C + CDNS_DP_SIZE * (n))
+
+#define CDNS_DPN_CONFIG_BPM			BIT(18)
+#define CDNS_DPN_CONFIG_BGC			GENMASK(17, 16)
+#define CDNS_DPN_CONFIG_WL			GENMASK(12, 8)
+#define CDNS_DPN_CONFIG_PORT_DAT		GENMASK(3, 2)
+#define CDNS_DPN_CONFIG_PORT_FLOW		GENMASK(1, 0)
+
+#define CDNS_DPN_SAMPLE_CTRL_SI			GENMASK(15, 0)
+
+#define CDNS_DPN_OFFSET_CTRL_1			GENMASK(7, 0)
+#define CDNS_DPN_OFFSET_CTRL_2			GENMASK(15, 8)
+
+#define CDNS_DPN_HCTRL_HSTOP			GENMASK(3, 0)
+#define CDNS_DPN_HCTRL_HSTART			GENMASK(7, 4)
+#define CDNS_DPN_HCTRL_LCTRL			GENMASK(10, 8)
+
+#define CDNS_PORTCTRL				0x130
+#define CDNS_PORTCTRL_DIRN			BIT(7)
+#define CDNS_PORTCTRL_BANK_INVERT		BIT(8)
+
+#define CDNS_PORT_OFFSET			0x80
+
+#define CDNS_PDI_CONFIG(n)			(0x1100 + (n) * 16)
+
+#define CDNS_PDI_CONFIG_SOFT_RESET		BIT(24)
+#define CDNS_PDI_CONFIG_CHANNEL			GENMASK(15, 8)
+#define CDNS_PDI_CONFIG_PORT			GENMASK(4, 0)
+
+/* Driver defaults */
+
+#define CDNS_DEFAULT_CLK_DIVIDER		0
+#define CDNS_DEFAULT_FRAME_SHAPE		0x30
+#define CDNS_DEFAULT_SSP_INTERVAL		0x18
+#define CDNS_TX_TIMEOUT				2000
+
+#define CDNS_PCM_PDI_OFFSET			0x2
+#define CDNS_PDM_PDI_OFFSET			0x6
+
+#define CDNS_SCP_RX_FIFOLEVEL			0x2
+
+/*
+ * register accessor helpers
+ */
+static inline u32 cdns_readl(struct sdw_cdns *cdns, int offset)
+{
+	return readl(cdns->registers + offset);
+}
+
+static inline void cdns_writel(struct sdw_cdns *cdns, int offset, u32 value)
+{
+	writel(value, cdns->registers + offset);
+}
+
+static inline void cdns_updatel(struct sdw_cdns *cdns,
+				int offset, u32 mask, u32 val)
+{
+	u32 tmp;
+
+	tmp = cdns_readl(cdns, offset);
+	tmp = (tmp & ~mask) | val;
+	cdns_writel(cdns, offset, tmp);
+}
+
+static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
+{
+	int timeout = 10;
+	u32 reg_read;
+
+	writel(value, cdns->registers + offset);
+
+	/* Wait for bit to be self cleared */
+	do {
+		reg_read = readl(cdns->registers + offset);
+		if ((reg_read & value) == 0)
+			return 0;
+
+		timeout--;
+		usleep_range(1, 50);
+	} while (timeout != 0);
+
+	return -EIO;
+}
+
+/*
+ * IRQ handling
+ */
+
+static int cdns_update_slave_status(struct sdw_cdns *cdns,
+					u32 slave0, u32 slave1)
+{
+	enum sdw_slave_status status[SDW_MAX_DEVICES];
+	bool is_slave = false;
+	u64 slave, mask;
+	int i, set_status;
+
+	/* combine the two status */
+	slave = ((u64)slave1 << 32) | slave0;
+	memset(status, 0, sizeof(status));
+
+	for (i = 0; i <= SDW_MAX_DEVICES; i++) {
+		mask = (slave >> (i * CDNS_MCP_SLAVE_STATUS_NUM)) &
+				CDNS_MCP_SLAVE_STATUS_BITS;
+		if (!mask)
+			continue;
+
+		is_slave = true;
+		set_status = 0;
+
+		if (mask & CDNS_MCP_SLAVE_INTSTAT_RESERVED) {
+			status[i] = SDW_SLAVE_RESERVED;
+			set_status++;
+		}
+
+		if (mask & CDNS_MCP_SLAVE_INTSTAT_ATTACHED) {
+			status[i] = SDW_SLAVE_ATTACHED;
+			set_status++;
+		}
+
+		if (mask & CDNS_MCP_SLAVE_INTSTAT_ALERT) {
+			status[i] = SDW_SLAVE_ALERT;
+			set_status++;
+		}
+
+		if (mask & CDNS_MCP_SLAVE_INTSTAT_NPRESENT) {
+			status[i] = SDW_SLAVE_UNATTACHED;
+			set_status++;
+		}
+
+		/* first check if Slave reported multiple status */
+		if (set_status > 1) {
+			dev_warn(cdns->dev,
+					"Slave reported multiple Status: %d\n",
+					status[i]);
+			/*
+			 * TODO: we need to reread the status here by
+			 * issuing a PING cmd
+			 */
+		}
+	}
+
+	if (is_slave)
+		return sdw_handle_slave_status(&cdns->bus, status);
+
+	return 0;
+}
+
+irqreturn_t sdw_cdns_irq(int irq, void *dev_id)
+{
+	struct sdw_cdns *cdns = dev_id;
+	u32 int_status, clear_status = 0;
+	int ret = IRQ_HANDLED;
+
+	/* Check if the link is up */
+	if (!cdns->link_up)
+		return IRQ_NONE;
+
+	int_status = cdns_readl(cdns, CDNS_MCP_INTSTAT);
+
+	if (!(int_status & CDNS_MCP_INT_IRQ))
+		return IRQ_NONE;
+
+	if (int_status & CDNS_MCP_INT_CTRL_CLASH) {
+
+		/* Slave is driving bit slot during control word */
+		dev_err_ratelimited(cdns->dev, "Bus clash for control word\n");
+		clear_status |= CDNS_MCP_INT_CTRL_CLASH;
+	}
+
+	if (int_status & CDNS_MCP_INT_DATA_CLASH) {
+		/*
+		 * Multiple slaves trying to drive bit slot, or issue with
+		 * ownership of data bits or Slave gone bonkers
+		 */
+		dev_err_ratelimited(cdns->dev, "Bus clash for data word\n");
+		clear_status |= CDNS_MCP_INT_DATA_CLASH;
+	}
+
+	if (int_status & CDNS_MCP_INT_SLAVE_MASK) {
+		/* Mask the Slave interrupt and wake thread */
+		cdns_updatel(cdns, CDNS_MCP_INTMASK,
+				CDNS_MCP_INT_SLAVE_MASK, 0);
+
+		clear_status &= ~CDNS_MCP_INT_SLAVE_MASK;
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	cdns_writel(cdns, CDNS_MCP_INTSTAT, clear_status);
+	return ret;
+}
+EXPORT_SYMBOL(sdw_cdns_irq);
+
+irqreturn_t sdw_cdns_thread(int irq, void *dev_id)
+{
+	struct sdw_cdns *cdns = dev_id;
+	u32 slave0, slave1;
+
+	dev_dbg(cdns->dev, "Slave status change\n");
+
+	slave0 = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT0);
+	slave1 = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT1);
+
+	cdns_update_slave_status(cdns, slave0, slave1);
+	cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT0, slave0);
+	cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT1, slave1);
+
+	/* clear and unmask Slave interrupt now */
+	cdns_writel(cdns, CDNS_MCP_INTSTAT, CDNS_MCP_INT_SLAVE_MASK);
+	cdns_updatel(cdns, CDNS_MCP_INTMASK,
+			CDNS_MCP_INT_SLAVE_MASK, CDNS_MCP_INT_SLAVE_MASK);
+
+	return IRQ_HANDLED;
+}
+EXPORT_SYMBOL(sdw_cdns_thread);
+
+/*
+ * init routines
+ */
+
+/**
+ * sdw_cdns_init: Cadence initialization
+ *
+ * @cdns: Cadence instance
+ */
+int sdw_cdns_init(struct sdw_cdns *cdns)
+{
+	u32 val;
+	int ret;
+
+	/* Exit clock stop */
+	ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL,
+			CDNS_MCP_CONTROL_CLK_STOP_CLR);
+	if (ret < 0) {
+		dev_err(cdns->dev, "Couldn't exit from clock stop\n");
+		return ret;
+	}
+
+	/* Set clock divider */
+	val = cdns_readl(cdns, CDNS_MCP_CLK_CTRL0);
+	val |= CDNS_DEFAULT_CLK_DIVIDER;
+	cdns_writel(cdns, CDNS_MCP_CLK_CTRL0, val);
+
+	/* Set the default frame shape */
+	cdns_writel(cdns, CDNS_MCP_FRAME_SHAPE_INIT, CDNS_DEFAULT_FRAME_SHAPE);
+
+	/* Set SSP interval to default value */
+	cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, CDNS_DEFAULT_SSP_INTERVAL);
+	cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, CDNS_DEFAULT_SSP_INTERVAL);
+
+	/* Set cmd accept mode */
+	cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT,
+					CDNS_MCP_CONTROL_CMD_ACCEPT);
+
+	/* Configure mcp config */
+	val = cdns_readl(cdns, CDNS_MCP_CONFIG);
+
+	/* Set Max cmd retry to 15 */
+	val |= CDNS_MCP_CONFIG_MCMD_RETRY;
+
+	/* Set frame delay between PREQ and ping frame to 15 frames */
+	val |= 0xF << SDW_REG_SHIFT(CDNS_MCP_CONFIG_MPREQ_DELAY);
+
+	/* Disable auto bus release */
+	val &= ~CDNS_MCP_CONFIG_BUS_REL;
+
+	/* Disable sniffer mode */
+	val &= ~CDNS_MCP_CONFIG_SNIFFER;
+
+	/* Set cmd mode for Tx and Rx cmds */
+	val &= ~CDNS_MCP_CONFIG_CMD;
+
+	/* Set operation to normal */
+	val &= ~CDNS_MCP_CONFIG_OP;
+	val |= CDNS_MCP_CONFIG_OP_NORMAL;
+
+	cdns_writel(cdns, CDNS_MCP_CONFIG, val);
+
+	return 0;
+}
+EXPORT_SYMBOL(sdw_cdns_init);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Cadence Soundwire Library");
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h
new file mode 100644
index 000000000000..a8cb82a15126
--- /dev/null
+++ b/drivers/soundwire/cadence_master.h
@@ -0,0 +1,82 @@
+/*
+ *  This file is provided under a dual BSD/GPLv2 license.  When using or
+ *  redistributing this file, you may do so under either license.
+ *
+ *  SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+ *
+ *  GPL LICENSE SUMMARY
+ *
+ *  Copyright(c) 2015-17 Intel Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of version 2 of the GNU General Public License as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  BSD LICENSE
+ *
+ *  Copyright(c) 2015-17 Intel Corporation.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in
+ *      the documentation and/or other materials provided with the
+ *      distribution.
+ *    * Neither the name of Intel Corporation nor the names of its
+ *      contributors may be used to endorse or promote products derived
+ *      from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#ifndef __SDW_CADENCE_H
+#define __SDW_CADENCE_H
+
+/**
+ * struct sdw_cdns: Cadence driver context
+ *
+ * @dev: Linux device
+ * @bus: Bus handle
+ * @instance: instance number
+ * @registers: Cadence registers
+ * @link_up: Link status
+ */
+struct sdw_cdns {
+	struct device *dev;
+	struct sdw_bus bus;
+	unsigned int instance;
+
+	void __iomem *registers;
+
+	bool link_up;
+};
+
+#define bus_to_cdns(_bus) container_of(_bus, struct sdw_cdns, bus)
+
+/* Exported symbols */
+
+irqreturn_t sdw_cdns_irq(int irq, void *dev_id);
+irqreturn_t sdw_cdns_thread(int irq, void *dev_id);
+
+int sdw_cdns_init(struct sdw_cdns *cdns);
+
+#endif /* __SDW_CADENCE_H */
-- 
2.7.4