Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1490 insertions, 0 deletions

diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
new file mode 100644
index 0000000000..4c3eb97203
--- /dev/null
+++ b/drivers/dma/qcom/bam_dma.c
@@ -0,0 +1,1490 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ */
+/*
+ * QCOM BAM DMA engine driver
+ *
+ * QCOM BAM DMA blocks are distributed amongst a number of the on-chip
+ * peripherals on the MSM 8x74.  The configuration of the channels are dependent
+ * on the way they are hard wired to that specific peripheral.  The peripheral
+ * device tree entries specify the configuration of each channel.
+ *
+ * The DMA controller requires the use of external memory for storage of the
+ * hardware descriptors for each channel.  The descriptor FIFO is accessed as a
+ * circular buffer and operations are managed according to the offset within the
+ * FIFO.  After pipe/channel reset, all of the pipe registers and internal state
+ * are back to defaults.
+ *
+ * During DMA operations, we write descriptors to the FIFO, being careful to
+ * handle wrapping and then write the last FIFO offset to that channel's
+ * P_EVNT_REG register to kick off the transaction.  The P_SW_OFSTS register
+ * indicates the current FIFO offset that is being processed, so there is some
+ * indication of where the hardware is currently working.
+ */
+
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_dma.h>
+#include <linux/circ_buf.h>
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/pm_runtime.h>
+
+#include "../dmaengine.h"
+#include "../virt-dma.h"
+
+struct bam_desc_hw {
+	__le32 addr;		/* Buffer physical address */
+	__le16 size;		/* Buffer size in bytes */
+	__le16 flags;
+};
+
+#define BAM_DMA_AUTOSUSPEND_DELAY 100
+
+#define DESC_FLAG_INT BIT(15)
+#define DESC_FLAG_EOT BIT(14)
+#define DESC_FLAG_EOB BIT(13)
+#define DESC_FLAG_NWD BIT(12)
+#define DESC_FLAG_CMD BIT(11)
+
+struct bam_async_desc {
+	struct virt_dma_desc vd;
+
+	u32 num_desc;
+	u32 xfer_len;
+
+	/* transaction flags, EOT|EOB|NWD */
+	u16 flags;
+
+	struct bam_desc_hw *curr_desc;
+
+	/* list node for the desc in the bam_chan list of descriptors */
+	struct list_head desc_node;
+	enum dma_transfer_direction dir;
+	size_t length;
+	struct bam_desc_hw desc[];
+};
+
+enum bam_reg {
+	BAM_CTRL,
+	BAM_REVISION,
+	BAM_NUM_PIPES,
+	BAM_DESC_CNT_TRSHLD,
+	BAM_IRQ_SRCS,
+	BAM_IRQ_SRCS_MSK,
+	BAM_IRQ_SRCS_UNMASKED,
+	BAM_IRQ_STTS,
+	BAM_IRQ_CLR,
+	BAM_IRQ_EN,
+	BAM_CNFG_BITS,
+	BAM_IRQ_SRCS_EE,
+	BAM_IRQ_SRCS_MSK_EE,
+	BAM_P_CTRL,
+	BAM_P_RST,
+	BAM_P_HALT,
+	BAM_P_IRQ_STTS,
+	BAM_P_IRQ_CLR,
+	BAM_P_IRQ_EN,
+	BAM_P_EVNT_DEST_ADDR,
+	BAM_P_EVNT_REG,
+	BAM_P_SW_OFSTS,
+	BAM_P_DATA_FIFO_ADDR,
+	BAM_P_DESC_FIFO_ADDR,
+	BAM_P_EVNT_GEN_TRSHLD,
+	BAM_P_FIFO_SIZES,
+};
+
+struct reg_offset_data {
+	u32 base_offset;
+	unsigned int pipe_mult, evnt_mult, ee_mult;
+};
+
+static const struct reg_offset_data bam_v1_3_reg_info[] = {
+	[BAM_CTRL]		= { 0x0F80, 0x00, 0x00, 0x00 },
+	[BAM_REVISION]		= { 0x0F84, 0x00, 0x00, 0x00 },
+	[BAM_NUM_PIPES]		= { 0x0FBC, 0x00, 0x00, 0x00 },
+	[BAM_DESC_CNT_TRSHLD]	= { 0x0F88, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS]		= { 0x0F8C, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_MSK]	= { 0x0F90, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0FB0, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_STTS]		= { 0x0F94, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_CLR]		= { 0x0F98, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_EN]		= { 0x0F9C, 0x00, 0x00, 0x00 },
+	[BAM_CNFG_BITS]		= { 0x0FFC, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_EE]	= { 0x1800, 0x00, 0x00, 0x80 },
+	[BAM_IRQ_SRCS_MSK_EE]	= { 0x1804, 0x00, 0x00, 0x80 },
+	[BAM_P_CTRL]		= { 0x0000, 0x80, 0x00, 0x00 },
+	[BAM_P_RST]		= { 0x0004, 0x80, 0x00, 0x00 },
+	[BAM_P_HALT]		= { 0x0008, 0x80, 0x00, 0x00 },
+	[BAM_P_IRQ_STTS]	= { 0x0010, 0x80, 0x00, 0x00 },
+	[BAM_P_IRQ_CLR]		= { 0x0014, 0x80, 0x00, 0x00 },
+	[BAM_P_IRQ_EN]		= { 0x0018, 0x80, 0x00, 0x00 },
+	[BAM_P_EVNT_DEST_ADDR]	= { 0x102C, 0x00, 0x40, 0x00 },
+	[BAM_P_EVNT_REG]	= { 0x1018, 0x00, 0x40, 0x00 },
+	[BAM_P_SW_OFSTS]	= { 0x1000, 0x00, 0x40, 0x00 },
+	[BAM_P_DATA_FIFO_ADDR]	= { 0x1024, 0x00, 0x40, 0x00 },
+	[BAM_P_DESC_FIFO_ADDR]	= { 0x101C, 0x00, 0x40, 0x00 },
+	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1028, 0x00, 0x40, 0x00 },
+	[BAM_P_FIFO_SIZES]	= { 0x1020, 0x00, 0x40, 0x00 },
+};
+
+static const struct reg_offset_data bam_v1_4_reg_info[] = {
+	[BAM_CTRL]		= { 0x0000, 0x00, 0x00, 0x00 },
+	[BAM_REVISION]		= { 0x0004, 0x00, 0x00, 0x00 },
+	[BAM_NUM_PIPES]		= { 0x003C, 0x00, 0x00, 0x00 },
+	[BAM_DESC_CNT_TRSHLD]	= { 0x0008, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS]		= { 0x000C, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_MSK]	= { 0x0010, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_UNMASKED]	= { 0x0030, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_STTS]		= { 0x0014, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_CLR]		= { 0x0018, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_EN]		= { 0x001C, 0x00, 0x00, 0x00 },
+	[BAM_CNFG_BITS]		= { 0x007C, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_EE]	= { 0x0800, 0x00, 0x00, 0x80 },
+	[BAM_IRQ_SRCS_MSK_EE]	= { 0x0804, 0x00, 0x00, 0x80 },
+	[BAM_P_CTRL]		= { 0x1000, 0x1000, 0x00, 0x00 },
+	[BAM_P_RST]		= { 0x1004, 0x1000, 0x00, 0x00 },
+	[BAM_P_HALT]		= { 0x1008, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_STTS]	= { 0x1010, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_CLR]		= { 0x1014, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_EN]		= { 0x1018, 0x1000, 0x00, 0x00 },
+	[BAM_P_EVNT_DEST_ADDR]	= { 0x182C, 0x00, 0x1000, 0x00 },
+	[BAM_P_EVNT_REG]	= { 0x1818, 0x00, 0x1000, 0x00 },
+	[BAM_P_SW_OFSTS]	= { 0x1800, 0x00, 0x1000, 0x00 },
+	[BAM_P_DATA_FIFO_ADDR]	= { 0x1824, 0x00, 0x1000, 0x00 },
+	[BAM_P_DESC_FIFO_ADDR]	= { 0x181C, 0x00, 0x1000, 0x00 },
+	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x1828, 0x00, 0x1000, 0x00 },
+	[BAM_P_FIFO_SIZES]	= { 0x1820, 0x00, 0x1000, 0x00 },
+};
+
+static const struct reg_offset_data bam_v1_7_reg_info[] = {
+	[BAM_CTRL]		= { 0x00000, 0x00, 0x00, 0x00 },
+	[BAM_REVISION]		= { 0x01000, 0x00, 0x00, 0x00 },
+	[BAM_NUM_PIPES]		= { 0x01008, 0x00, 0x00, 0x00 },
+	[BAM_DESC_CNT_TRSHLD]	= { 0x00008, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS]		= { 0x03010, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_MSK]	= { 0x03014, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_UNMASKED]	= { 0x03018, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_STTS]		= { 0x00014, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_CLR]		= { 0x00018, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_EN]		= { 0x0001C, 0x00, 0x00, 0x00 },
+	[BAM_CNFG_BITS]		= { 0x0007C, 0x00, 0x00, 0x00 },
+	[BAM_IRQ_SRCS_EE]	= { 0x03000, 0x00, 0x00, 0x1000 },
+	[BAM_IRQ_SRCS_MSK_EE]	= { 0x03004, 0x00, 0x00, 0x1000 },
+	[BAM_P_CTRL]		= { 0x13000, 0x1000, 0x00, 0x00 },
+	[BAM_P_RST]		= { 0x13004, 0x1000, 0x00, 0x00 },
+	[BAM_P_HALT]		= { 0x13008, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_STTS]	= { 0x13010, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_CLR]		= { 0x13014, 0x1000, 0x00, 0x00 },
+	[BAM_P_IRQ_EN]		= { 0x13018, 0x1000, 0x00, 0x00 },
+	[BAM_P_EVNT_DEST_ADDR]	= { 0x1382C, 0x00, 0x1000, 0x00 },
+	[BAM_P_EVNT_REG]	= { 0x13818, 0x00, 0x1000, 0x00 },
+	[BAM_P_SW_OFSTS]	= { 0x13800, 0x00, 0x1000, 0x00 },
+	[BAM_P_DATA_FIFO_ADDR]	= { 0x13824, 0x00, 0x1000, 0x00 },
+	[BAM_P_DESC_FIFO_ADDR]	= { 0x1381C, 0x00, 0x1000, 0x00 },
+	[BAM_P_EVNT_GEN_TRSHLD]	= { 0x13828, 0x00, 0x1000, 0x00 },
+	[BAM_P_FIFO_SIZES]	= { 0x13820, 0x00, 0x1000, 0x00 },
+};
+
+/* BAM CTRL */
+#define BAM_SW_RST			BIT(0)
+#define BAM_EN				BIT(1)
+#define BAM_EN_ACCUM			BIT(4)
+#define BAM_TESTBUS_SEL_SHIFT		5
+#define BAM_TESTBUS_SEL_MASK		0x3F
+#define BAM_DESC_CACHE_SEL_SHIFT	13
+#define BAM_DESC_CACHE_SEL_MASK		0x3
+#define BAM_CACHED_DESC_STORE		BIT(15)
+#define IBC_DISABLE			BIT(16)
+
+/* BAM REVISION */
+#define REVISION_SHIFT		0
+#define REVISION_MASK		0xFF
+#define NUM_EES_SHIFT		8
+#define NUM_EES_MASK		0xF
+#define CE_BUFFER_SIZE		BIT(13)
+#define AXI_ACTIVE		BIT(14)
+#define USE_VMIDMT		BIT(15)
+#define SECURED			BIT(16)
+#define BAM_HAS_NO_BYPASS	BIT(17)
+#define HIGH_FREQUENCY_BAM	BIT(18)
+#define INACTIV_TMRS_EXST	BIT(19)
+#define NUM_INACTIV_TMRS	BIT(20)
+#define DESC_CACHE_DEPTH_SHIFT	21
+#define DESC_CACHE_DEPTH_1	(0 << DESC_CACHE_DEPTH_SHIFT)
+#define DESC_CACHE_DEPTH_2	(1 << DESC_CACHE_DEPTH_SHIFT)
+#define DESC_CACHE_DEPTH_3	(2 << DESC_CACHE_DEPTH_SHIFT)
+#define DESC_CACHE_DEPTH_4	(3 << DESC_CACHE_DEPTH_SHIFT)
+#define CMD_DESC_EN		BIT(23)
+#define INACTIV_TMR_BASE_SHIFT	24
+#define INACTIV_TMR_BASE_MASK	0xFF
+
+/* BAM NUM PIPES */
+#define BAM_NUM_PIPES_SHIFT		0
+#define BAM_NUM_PIPES_MASK		0xFF
+#define PERIPH_NON_PIPE_GRP_SHIFT	16
+#define PERIPH_NON_PIP_GRP_MASK		0xFF
+#define BAM_NON_PIPE_GRP_SHIFT		24
+#define BAM_NON_PIPE_GRP_MASK		0xFF
+
+/* BAM CNFG BITS */
+#define BAM_PIPE_CNFG		BIT(2)
+#define BAM_FULL_PIPE		BIT(11)
+#define BAM_NO_EXT_P_RST	BIT(12)
+#define BAM_IBC_DISABLE		BIT(13)
+#define BAM_SB_CLK_REQ		BIT(14)
+#define BAM_PSM_CSW_REQ		BIT(15)
+#define BAM_PSM_P_RES		BIT(16)
+#define BAM_AU_P_RES		BIT(17)
+#define BAM_SI_P_RES		BIT(18)
+#define BAM_WB_P_RES		BIT(19)
+#define BAM_WB_BLK_CSW		BIT(20)
+#define BAM_WB_CSW_ACK_IDL	BIT(21)
+#define BAM_WB_RETR_SVPNT	BIT(22)
+#define BAM_WB_DSC_AVL_P_RST	BIT(23)
+#define BAM_REG_P_EN		BIT(24)
+#define BAM_PSM_P_HD_DATA	BIT(25)
+#define BAM_AU_ACCUMED		BIT(26)
+#define BAM_CMD_ENABLE		BIT(27)
+
+#define BAM_CNFG_BITS_DEFAULT	(BAM_PIPE_CNFG |	\
+				 BAM_NO_EXT_P_RST |	\
+				 BAM_IBC_DISABLE |	\
+				 BAM_SB_CLK_REQ |	\
+				 BAM_PSM_CSW_REQ |	\
+				 BAM_PSM_P_RES |	\
+				 BAM_AU_P_RES |		\
+				 BAM_SI_P_RES |		\
+				 BAM_WB_P_RES |		\
+				 BAM_WB_BLK_CSW |	\
+				 BAM_WB_CSW_ACK_IDL |	\
+				 BAM_WB_RETR_SVPNT |	\
+				 BAM_WB_DSC_AVL_P_RST |	\
+				 BAM_REG_P_EN |		\
+				 BAM_PSM_P_HD_DATA |	\
+				 BAM_AU_ACCUMED |	\
+				 BAM_CMD_ENABLE)
+
+/* PIPE CTRL */
+#define P_EN			BIT(1)
+#define P_DIRECTION		BIT(3)
+#define P_SYS_STRM		BIT(4)
+#define P_SYS_MODE		BIT(5)
+#define P_AUTO_EOB		BIT(6)
+#define P_AUTO_EOB_SEL_SHIFT	7
+#define P_AUTO_EOB_SEL_512	(0 << P_AUTO_EOB_SEL_SHIFT)
+#define P_AUTO_EOB_SEL_256	(1 << P_AUTO_EOB_SEL_SHIFT)
+#define P_AUTO_EOB_SEL_128	(2 << P_AUTO_EOB_SEL_SHIFT)
+#define P_AUTO_EOB_SEL_64	(3 << P_AUTO_EOB_SEL_SHIFT)
+#define P_PREFETCH_LIMIT_SHIFT	9
+#define P_PREFETCH_LIMIT_32	(0 << P_PREFETCH_LIMIT_SHIFT)
+#define P_PREFETCH_LIMIT_16	(1 << P_PREFETCH_LIMIT_SHIFT)
+#define P_PREFETCH_LIMIT_4	(2 << P_PREFETCH_LIMIT_SHIFT)
+#define P_WRITE_NWD		BIT(11)
+#define P_LOCK_GROUP_SHIFT	16
+#define P_LOCK_GROUP_MASK	0x1F
+
+/* BAM_DESC_CNT_TRSHLD */
+#define CNT_TRSHLD		0xffff
+#define DEFAULT_CNT_THRSHLD	0x4
+
+/* BAM_IRQ_SRCS */
+#define BAM_IRQ			BIT(31)
+#define P_IRQ			0x7fffffff
+
+/* BAM_IRQ_SRCS_MSK */
+#define BAM_IRQ_MSK		BAM_IRQ
+#define P_IRQ_MSK		P_IRQ
+
+/* BAM_IRQ_STTS */
+#define BAM_TIMER_IRQ		BIT(4)
+#define BAM_EMPTY_IRQ		BIT(3)
+#define BAM_ERROR_IRQ		BIT(2)
+#define BAM_HRESP_ERR_IRQ	BIT(1)
+
+/* BAM_IRQ_CLR */
+#define BAM_TIMER_CLR		BIT(4)
+#define BAM_EMPTY_CLR		BIT(3)
+#define BAM_ERROR_CLR		BIT(2)
+#define BAM_HRESP_ERR_CLR	BIT(1)
+
+/* BAM_IRQ_EN */
+#define BAM_TIMER_EN		BIT(4)
+#define BAM_EMPTY_EN		BIT(3)
+#define BAM_ERROR_EN		BIT(2)
+#define BAM_HRESP_ERR_EN	BIT(1)
+
+/* BAM_P_IRQ_EN */
+#define P_PRCSD_DESC_EN		BIT(0)
+#define P_TIMER_EN		BIT(1)
+#define P_WAKE_EN		BIT(2)
+#define P_OUT_OF_DESC_EN	BIT(3)
+#define P_ERR_EN		BIT(4)
+#define P_TRNSFR_END_EN		BIT(5)
+#define P_DEFAULT_IRQS_EN	(P_PRCSD_DESC_EN | P_ERR_EN | P_TRNSFR_END_EN)
+
+/* BAM_P_SW_OFSTS */
+#define P_SW_OFSTS_MASK		0xffff
+
+#define BAM_DESC_FIFO_SIZE	SZ_32K
+#define MAX_DESCRIPTORS (BAM_DESC_FIFO_SIZE / sizeof(struct bam_desc_hw) - 1)
+#define BAM_FIFO_SIZE	(SZ_32K - 8)
+#define IS_BUSY(chan)	(CIRC_SPACE(bchan->tail, bchan->head,\
+			 MAX_DESCRIPTORS + 1) == 0)
+
+struct bam_chan {
+	struct virt_dma_chan vc;
+
+	struct bam_device *bdev;
+
+	/* configuration from device tree */
+	u32 id;
+
+	/* runtime configuration */
+	struct dma_slave_config slave;
+
+	/* fifo storage */
+	struct bam_desc_hw *fifo_virt;
+	dma_addr_t fifo_phys;
+
+	/* fifo markers */
+	unsigned short head;		/* start of active descriptor entries */
+	unsigned short tail;		/* end of active descriptor entries */
+
+	unsigned int initialized;	/* is the channel hw initialized? */
+	unsigned int paused;		/* is the channel paused? */
+	unsigned int reconfigure;	/* new slave config? */
+	/* list of descriptors currently processed */
+	struct list_head desc_list;
+
+	struct list_head node;
+};
+
+static inline struct bam_chan *to_bam_chan(struct dma_chan *common)
+{
+	return container_of(common, struct bam_chan, vc.chan);
+}
+
+struct bam_device {
+	void __iomem *regs;
+	struct device *dev;
+	struct dma_device common;
+	struct bam_chan *channels;
+	u32 num_channels;
+	u32 num_ees;
+
+	/* execution environment ID, from DT */
+	u32 ee;
+	bool controlled_remotely;
+	bool powered_remotely;
+	u32 active_channels;
+
+	const struct reg_offset_data *layout;
+
+	struct clk *bamclk;
+	int irq;
+
+	/* dma start transaction tasklet */
+	struct tasklet_struct task;
+};
+
+/**
+ * bam_addr - returns BAM register address
+ * @bdev: bam device
+ * @pipe: pipe instance (ignored when register doesn't have multiple instances)
+ * @reg:  register enum
+ */
+static inline void __iomem *bam_addr(struct bam_device *bdev, u32 pipe,
+		enum bam_reg reg)
+{
+	const struct reg_offset_data r = bdev->layout[reg];
+
+	return bdev->regs + r.base_offset +
+		r.pipe_mult * pipe +
+		r.evnt_mult * pipe +
+		r.ee_mult * bdev->ee;
+}
+
+/**
+ * bam_reset() - reset and initialize BAM registers
+ * @bdev: bam device
+ */
+static void bam_reset(struct bam_device *bdev)
+{
+	u32 val;
+
+	/* s/w reset bam */
+	/* after reset all pipes are disabled and idle */
+	val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
+	val |= BAM_SW_RST;
+	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
+	val &= ~BAM_SW_RST;
+	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
+
+	/* make sure previous stores are visible before enabling BAM */
+	wmb();
+
+	/* enable bam */
+	val |= BAM_EN;
+	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
+
+	/* set descriptor threshhold, start with 4 bytes */
+	writel_relaxed(DEFAULT_CNT_THRSHLD,
+			bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
+
+	/* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
+	writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS));
+
+	/* enable irqs for errors */
+	writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
+			bam_addr(bdev, 0, BAM_IRQ_EN));
+
+	/* unmask global bam interrupt */
+	writel_relaxed(BAM_IRQ_MSK, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+}
+
+/**
+ * bam_reset_channel - Reset individual BAM DMA channel
+ * @bchan: bam channel
+ *
+ * This function resets a specific BAM channel
+ */
+static void bam_reset_channel(struct bam_chan *bchan)
+{
+	struct bam_device *bdev = bchan->bdev;
+
+	lockdep_assert_held(&bchan->vc.lock);
+
+	/* reset channel */
+	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_RST));
+	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_RST));
+
+	/* don't allow cpu to reorder BAM register accesses done after this */
+	wmb();
+
+	/* make sure hw is initialized when channel is used the first time  */
+	bchan->initialized = 0;
+}
+
+/**
+ * bam_chan_init_hw - Initialize channel hardware
+ * @bchan: bam channel
+ * @dir: DMA transfer direction
+ *
+ * This function resets and initializes the BAM channel
+ */
+static void bam_chan_init_hw(struct bam_chan *bchan,
+	enum dma_transfer_direction dir)
+{
+	struct bam_device *bdev = bchan->bdev;
+	u32 val;
+
+	/* Reset the channel to clear internal state of the FIFO */
+	bam_reset_channel(bchan);
+
+	/*
+	 * write out 8 byte aligned address.  We have enough space for this
+	 * because we allocated 1 more descriptor (8 bytes) than we can use
+	 */
+	writel_relaxed(ALIGN(bchan->fifo_phys, sizeof(struct bam_desc_hw)),
+			bam_addr(bdev, bchan->id, BAM_P_DESC_FIFO_ADDR));
+	writel_relaxed(BAM_FIFO_SIZE,
+			bam_addr(bdev, bchan->id, BAM_P_FIFO_SIZES));
+
+	/* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
+	writel_relaxed(P_DEFAULT_IRQS_EN,
+			bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
+
+	/* unmask the specific pipe and EE combo */
+	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+	val |= BIT(bchan->id);
+	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+
+	/* don't allow cpu to reorder the channel enable done below */
+	wmb();
+
+	/* set fixed direction and mode, then enable channel */
+	val = P_EN | P_SYS_MODE;
+	if (dir == DMA_DEV_TO_MEM)
+		val |= P_DIRECTION;
+
+	writel_relaxed(val, bam_addr(bdev, bchan->id, BAM_P_CTRL));
+
+	bchan->initialized = 1;
+
+	/* init FIFO pointers */
+	bchan->head = 0;
+	bchan->tail = 0;
+}
+
+/**
+ * bam_alloc_chan - Allocate channel resources for DMA channel.
+ * @chan: specified channel
+ *
+ * This function allocates the FIFO descriptor memory
+ */
+static int bam_alloc_chan(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_device *bdev = bchan->bdev;
+
+	if (bchan->fifo_virt)
+		return 0;
+
+	/* allocate FIFO descriptor space, but only if necessary */
+	bchan->fifo_virt = dma_alloc_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
+					&bchan->fifo_phys, GFP_KERNEL);
+
+	if (!bchan->fifo_virt) {
+		dev_err(bdev->dev, "Failed to allocate desc fifo\n");
+		return -ENOMEM;
+	}
+
+	if (bdev->active_channels++ == 0 && bdev->powered_remotely)
+		bam_reset(bdev);
+
+	return 0;
+}
+
+/**
+ * bam_free_chan - Frees dma resources associated with specific channel
+ * @chan: specified channel
+ *
+ * Free the allocated fifo descriptor memory and channel resources
+ *
+ */
+static void bam_free_chan(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_device *bdev = bchan->bdev;
+	u32 val;
+	unsigned long flags;
+	int ret;
+
+	ret = pm_runtime_get_sync(bdev->dev);
+	if (ret < 0)
+		return;
+
+	vchan_free_chan_resources(to_virt_chan(chan));
+
+	if (!list_empty(&bchan->desc_list)) {
+		dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
+		goto err;
+	}
+
+	spin_lock_irqsave(&bchan->vc.lock, flags);
+	bam_reset_channel(bchan);
+	spin_unlock_irqrestore(&bchan->vc.lock, flags);
+
+	dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
+		    bchan->fifo_phys);
+	bchan->fifo_virt = NULL;
+
+	/* mask irq for pipe/channel */
+	val = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+	val &= ~BIT(bchan->id);
+	writel_relaxed(val, bam_addr(bdev, 0, BAM_IRQ_SRCS_MSK_EE));
+
+	/* disable irq */
+	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_IRQ_EN));
+
+	if (--bdev->active_channels == 0 && bdev->powered_remotely) {
+		/* s/w reset bam */
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_CTRL));
+		val |= BAM_SW_RST;
+		writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));
+	}
+
+err:
+	pm_runtime_mark_last_busy(bdev->dev);
+	pm_runtime_put_autosuspend(bdev->dev);
+}
+
+/**
+ * bam_slave_config - set slave configuration for channel
+ * @chan: dma channel
+ * @cfg: slave configuration
+ *
+ * Sets slave configuration for channel
+ *
+ */
+static int bam_slave_config(struct dma_chan *chan,
+			    struct dma_slave_config *cfg)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	unsigned long flag;
+
+	spin_lock_irqsave(&bchan->vc.lock, flag);
+	memcpy(&bchan->slave, cfg, sizeof(*cfg));
+	bchan->reconfigure = 1;
+	spin_unlock_irqrestore(&bchan->vc.lock, flag);
+
+	return 0;
+}
+
+/**
+ * bam_prep_slave_sg - Prep slave sg transaction
+ *
+ * @chan: dma channel
+ * @sgl: scatter gather list
+ * @sg_len: length of sg
+ * @direction: DMA transfer direction
+ * @flags: DMA flags
+ * @context: transfer context (unused)
+ */
+static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
+	struct scatterlist *sgl, unsigned int sg_len,
+	enum dma_transfer_direction direction, unsigned long flags,
+	void *context)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_device *bdev = bchan->bdev;
+	struct bam_async_desc *async_desc;
+	struct scatterlist *sg;
+	u32 i;
+	struct bam_desc_hw *desc;
+	unsigned int num_alloc = 0;
+
+
+	if (!is_slave_direction(direction)) {
+		dev_err(bdev->dev, "invalid dma direction\n");
+		return NULL;
+	}
+
+	/* calculate number of required entries */
+	for_each_sg(sgl, sg, sg_len, i)
+		num_alloc += DIV_ROUND_UP(sg_dma_len(sg), BAM_FIFO_SIZE);
+
+	/* allocate enough room to accomodate the number of entries */
+	async_desc = kzalloc(struct_size(async_desc, desc, num_alloc),
+			     GFP_NOWAIT);
+
+	if (!async_desc)
+		return NULL;
+
+	if (flags & DMA_PREP_FENCE)
+		async_desc->flags |= DESC_FLAG_NWD;
+
+	if (flags & DMA_PREP_INTERRUPT)
+		async_desc->flags |= DESC_FLAG_EOT;
+
+	async_desc->num_desc = num_alloc;
+	async_desc->curr_desc = async_desc->desc;
+	async_desc->dir = direction;
+
+	/* fill in temporary descriptors */
+	desc = async_desc->desc;
+	for_each_sg(sgl, sg, sg_len, i) {
+		unsigned int remainder = sg_dma_len(sg);
+		unsigned int curr_offset = 0;
+
+		do {
+			if (flags & DMA_PREP_CMD)
+				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
+
+			desc->addr = cpu_to_le32(sg_dma_address(sg) +
+						 curr_offset);
+
+			if (remainder > BAM_FIFO_SIZE) {
+				desc->size = cpu_to_le16(BAM_FIFO_SIZE);
+				remainder -= BAM_FIFO_SIZE;
+				curr_offset += BAM_FIFO_SIZE;
+			} else {
+				desc->size = cpu_to_le16(remainder);
+				remainder = 0;
+			}
+
+			async_desc->length += le16_to_cpu(desc->size);
+			desc++;
+		} while (remainder > 0);
+	}
+
+	return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
+}
+
+/**
+ * bam_dma_terminate_all - terminate all transactions on a channel
+ * @chan: bam dma channel
+ *
+ * Dequeues and frees all transactions
+ * No callbacks are done
+ *
+ */
+static int bam_dma_terminate_all(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_async_desc *async_desc, *tmp;
+	unsigned long flag;
+	LIST_HEAD(head);
+
+	/* remove all transactions, including active transaction */
+	spin_lock_irqsave(&bchan->vc.lock, flag);
+	/*
+	 * If we have transactions queued, then some might be committed to the
+	 * hardware in the desc fifo.  The only way to reset the desc fifo is
+	 * to do a hardware reset (either by pipe or the entire block).
+	 * bam_chan_init_hw() will trigger a pipe reset, and also reinit the
+	 * pipe.  If the pipe is left disabled (default state after pipe reset)
+	 * and is accessed by a connected hardware engine, a fatal error in
+	 * the BAM will occur.  There is a small window where this could happen
+	 * with bam_chan_init_hw(), but it is assumed that the caller has
+	 * stopped activity on any attached hardware engine.  Make sure to do
+	 * this first so that the BAM hardware doesn't cause memory corruption
+	 * by accessing freed resources.
+	 */
+	if (!list_empty(&bchan->desc_list)) {
+		async_desc = list_first_entry(&bchan->desc_list,
+					      struct bam_async_desc, desc_node);
+		bam_chan_init_hw(bchan, async_desc->dir);
+	}
+
+	list_for_each_entry_safe(async_desc, tmp,
+				 &bchan->desc_list, desc_node) {
+		list_add(&async_desc->vd.node, &bchan->vc.desc_issued);
+		list_del(&async_desc->desc_node);
+	}
+
+	vchan_get_all_descriptors(&bchan->vc, &head);
+	spin_unlock_irqrestore(&bchan->vc.lock, flag);
+
+	vchan_dma_desc_free_list(&bchan->vc, &head);
+
+	return 0;
+}
+
+/**
+ * bam_pause - Pause DMA channel
+ * @chan: dma channel
+ *
+ */
+static int bam_pause(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_device *bdev = bchan->bdev;
+	unsigned long flag;
+	int ret;
+
+	ret = pm_runtime_get_sync(bdev->dev);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_irqsave(&bchan->vc.lock, flag);
+	writel_relaxed(1, bam_addr(bdev, bchan->id, BAM_P_HALT));
+	bchan->paused = 1;
+	spin_unlock_irqrestore(&bchan->vc.lock, flag);
+	pm_runtime_mark_last_busy(bdev->dev);
+	pm_runtime_put_autosuspend(bdev->dev);
+
+	return 0;
+}
+
+/**
+ * bam_resume - Resume DMA channel operations
+ * @chan: dma channel
+ *
+ */
+static int bam_resume(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_device *bdev = bchan->bdev;
+	unsigned long flag;
+	int ret;
+
+	ret = pm_runtime_get_sync(bdev->dev);
+	if (ret < 0)
+		return ret;
+
+	spin_lock_irqsave(&bchan->vc.lock, flag);
+	writel_relaxed(0, bam_addr(bdev, bchan->id, BAM_P_HALT));
+	bchan->paused = 0;
+	spin_unlock_irqrestore(&bchan->vc.lock, flag);
+	pm_runtime_mark_last_busy(bdev->dev);
+	pm_runtime_put_autosuspend(bdev->dev);
+
+	return 0;
+}
+
+/**
+ * process_channel_irqs - processes the channel interrupts
+ * @bdev: bam controller
+ *
+ * This function processes the channel interrupts
+ *
+ */
+static u32 process_channel_irqs(struct bam_device *bdev)
+{
+	u32 i, srcs, pipe_stts, offset, avail;
+	unsigned long flags;
+	struct bam_async_desc *async_desc, *tmp;
+
+	srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE));
+
+	/* return early if no pipe/channel interrupts are present */
+	if (!(srcs & P_IRQ))
+		return srcs;
+
+	for (i = 0; i < bdev->num_channels; i++) {
+		struct bam_chan *bchan = &bdev->channels[i];
+
+		if (!(srcs & BIT(i)))
+			continue;
+
+		/* clear pipe irq */
+		pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS));
+
+		writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR));
+
+		spin_lock_irqsave(&bchan->vc.lock, flags);
+
+		offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) &
+				       P_SW_OFSTS_MASK;
+		offset /= sizeof(struct bam_desc_hw);
+
+		/* Number of bytes available to read */
+		avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1);
+
+		if (offset < bchan->head)
+			avail--;
+
+		list_for_each_entry_safe(async_desc, tmp,
+					 &bchan->desc_list, desc_node) {
+			/* Not enough data to read */
+			if (avail < async_desc->xfer_len)
+				break;
+
+			/* manage FIFO */
+			bchan->head += async_desc->xfer_len;
+			bchan->head %= MAX_DESCRIPTORS;
+
+			async_desc->num_desc -= async_desc->xfer_len;
+			async_desc->curr_desc += async_desc->xfer_len;
+			avail -= async_desc->xfer_len;
+
+			/*
+			 * if complete, process cookie. Otherwise
+			 * push back to front of desc_issued so that
+			 * it gets restarted by the tasklet
+			 */
+			if (!async_desc->num_desc) {
+				vchan_cookie_complete(&async_desc->vd);
+			} else {
+				list_add(&async_desc->vd.node,
+					 &bchan->vc.desc_issued);
+			}
+			list_del(&async_desc->desc_node);
+		}
+
+		spin_unlock_irqrestore(&bchan->vc.lock, flags);
+	}
+
+	return srcs;
+}
+
+/**
+ * bam_dma_irq - irq handler for bam controller
+ * @irq: IRQ of interrupt
+ * @data: callback data
+ *
+ * IRQ handler for the bam controller
+ */
+static irqreturn_t bam_dma_irq(int irq, void *data)
+{
+	struct bam_device *bdev = data;
+	u32 clr_mask = 0, srcs = 0;
+	int ret;
+
+	srcs |= process_channel_irqs(bdev);
+
+	/* kick off tasklet to start next dma transfer */
+	if (srcs & P_IRQ)
+		tasklet_schedule(&bdev->task);
+
+	ret = pm_runtime_get_sync(bdev->dev);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	if (srcs & BAM_IRQ) {
+		clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS));
+
+		/*
+		 * don't allow reorder of the various accesses to the BAM
+		 * registers
+		 */
+		mb();
+
+		writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR));
+	}
+
+	pm_runtime_mark_last_busy(bdev->dev);
+	pm_runtime_put_autosuspend(bdev->dev);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * bam_tx_status - returns status of transaction
+ * @chan: dma channel
+ * @cookie: transaction cookie
+ * @txstate: DMA transaction state
+ *
+ * Return status of dma transaction
+ */
+static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+		struct dma_tx_state *txstate)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	struct bam_async_desc *async_desc;
+	struct virt_dma_desc *vd;
+	int ret;
+	size_t residue = 0;
+	unsigned int i;
+	unsigned long flags;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	if (ret == DMA_COMPLETE)
+		return ret;
+
+	if (!txstate)
+		return bchan->paused ? DMA_PAUSED : ret;
+
+	spin_lock_irqsave(&bchan->vc.lock, flags);
+	vd = vchan_find_desc(&bchan->vc, cookie);
+	if (vd) {
+		residue = container_of(vd, struct bam_async_desc, vd)->length;
+	} else {
+		list_for_each_entry(async_desc, &bchan->desc_list, desc_node) {
+			if (async_desc->vd.tx.cookie != cookie)
+				continue;
+
+			for (i = 0; i < async_desc->num_desc; i++)
+				residue += le16_to_cpu(
+						async_desc->curr_desc[i].size);
+		}
+	}
+
+	spin_unlock_irqrestore(&bchan->vc.lock, flags);
+
+	dma_set_residue(txstate, residue);
+
+	if (ret == DMA_IN_PROGRESS && bchan->paused)
+		ret = DMA_PAUSED;
+
+	return ret;
+}
+
+/**
+ * bam_apply_new_config
+ * @bchan: bam dma channel
+ * @dir: DMA direction
+ */
+static void bam_apply_new_config(struct bam_chan *bchan,
+	enum dma_transfer_direction dir)
+{
+	struct bam_device *bdev = bchan->bdev;
+	u32 maxburst;
+
+	if (!bdev->controlled_remotely) {
+		if (dir == DMA_DEV_TO_MEM)
+			maxburst = bchan->slave.src_maxburst;
+		else
+			maxburst = bchan->slave.dst_maxburst;
+
+		writel_relaxed(maxburst,
+			       bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD));
+	}
+
+	bchan->reconfigure = 0;
+}
+
+/**
+ * bam_start_dma - start next transaction
+ * @bchan: bam dma channel
+ */
+static void bam_start_dma(struct bam_chan *bchan)
+{
+	struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc);
+	struct bam_device *bdev = bchan->bdev;
+	struct bam_async_desc *async_desc = NULL;
+	struct bam_desc_hw *desc;
+	struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
+					sizeof(struct bam_desc_hw));
+	int ret;
+	unsigned int avail;
+	struct dmaengine_desc_callback cb;
+
+	lockdep_assert_held(&bchan->vc.lock);
+
+	if (!vd)
+		return;
+
+	ret = pm_runtime_get_sync(bdev->dev);
+	if (ret < 0)
+		return;
+
+	while (vd && !IS_BUSY(bchan)) {
+		list_del(&vd->node);
+
+		async_desc = container_of(vd, struct bam_async_desc, vd);
+
+		/* on first use, initialize the channel hardware */
+		if (!bchan->initialized)
+			bam_chan_init_hw(bchan, async_desc->dir);
+
+		/* apply new slave config changes, if necessary */
+		if (bchan->reconfigure)
+			bam_apply_new_config(bchan, async_desc->dir);
+
+		desc = async_desc->curr_desc;
+		avail = CIRC_SPACE(bchan->tail, bchan->head,
+				   MAX_DESCRIPTORS + 1);
+
+		if (async_desc->num_desc > avail)
+			async_desc->xfer_len = avail;
+		else
+			async_desc->xfer_len = async_desc->num_desc;
+
+		/* set any special flags on the last descriptor */
+		if (async_desc->num_desc == async_desc->xfer_len)
+			desc[async_desc->xfer_len - 1].flags |=
+						cpu_to_le16(async_desc->flags);
+
+		vd = vchan_next_desc(&bchan->vc);
+
+		dmaengine_desc_get_callback(&async_desc->vd.tx, &cb);
+
+		/*
+		 * An interrupt is generated at this desc, if
+		 *  - FIFO is FULL.
+		 *  - No more descriptors to add.
+		 *  - If a callback completion was requested for this DESC,
+		 *     In this case, BAM will deliver the completion callback
+		 *     for this desc and continue processing the next desc.
+		 */
+		if (((avail <= async_desc->xfer_len) || !vd ||
+		     dmaengine_desc_callback_valid(&cb)) &&
+		    !(async_desc->flags & DESC_FLAG_EOT))
+			desc[async_desc->xfer_len - 1].flags |=
+				cpu_to_le16(DESC_FLAG_INT);
+
+		if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) {
+			u32 partial = MAX_DESCRIPTORS - bchan->tail;
+
+			memcpy(&fifo[bchan->tail], desc,
+			       partial * sizeof(struct bam_desc_hw));
+			memcpy(fifo, &desc[partial],
+			       (async_desc->xfer_len - partial) *
+				sizeof(struct bam_desc_hw));
+		} else {
+			memcpy(&fifo[bchan->tail], desc,
+			       async_desc->xfer_len *
+			       sizeof(struct bam_desc_hw));
+		}
+
+		bchan->tail += async_desc->xfer_len;
+		bchan->tail %= MAX_DESCRIPTORS;
+		list_add_tail(&async_desc->desc_node, &bchan->desc_list);
+	}
+
+	/* ensure descriptor writes and dma start not reordered */
+	wmb();
+	writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
+			bam_addr(bdev, bchan->id, BAM_P_EVNT_REG));
+
+	pm_runtime_mark_last_busy(bdev->dev);
+	pm_runtime_put_autosuspend(bdev->dev);
+}
+
+/**
+ * dma_tasklet - DMA IRQ tasklet
+ * @t: tasklet argument (bam controller structure)
+ *
+ * Sets up next DMA operation and then processes all completed transactions
+ */
+static void dma_tasklet(struct tasklet_struct *t)
+{
+	struct bam_device *bdev = from_tasklet(bdev, t, task);
+	struct bam_chan *bchan;
+	unsigned long flags;
+	unsigned int i;
+
+	/* go through the channels and kick off transactions */
+	for (i = 0; i < bdev->num_channels; i++) {
+		bchan = &bdev->channels[i];
+		spin_lock_irqsave(&bchan->vc.lock, flags);
+
+		if (!list_empty(&bchan->vc.desc_issued) && !IS_BUSY(bchan))
+			bam_start_dma(bchan);
+		spin_unlock_irqrestore(&bchan->vc.lock, flags);
+	}
+
+}
+
+/**
+ * bam_issue_pending - starts pending transactions
+ * @chan: dma channel
+ *
+ * Calls tasklet directly which in turn starts any pending transactions
+ */
+static void bam_issue_pending(struct dma_chan *chan)
+{
+	struct bam_chan *bchan = to_bam_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&bchan->vc.lock, flags);
+
+	/* if work pending and idle, start a transaction */
+	if (vchan_issue_pending(&bchan->vc) && !IS_BUSY(bchan))
+		bam_start_dma(bchan);
+
+	spin_unlock_irqrestore(&bchan->vc.lock, flags);
+}
+
+/**
+ * bam_dma_free_desc - free descriptor memory
+ * @vd: virtual descriptor
+ *
+ */
+static void bam_dma_free_desc(struct virt_dma_desc *vd)
+{
+	struct bam_async_desc *async_desc = container_of(vd,
+			struct bam_async_desc, vd);
+
+	kfree(async_desc);
+}
+
+static struct dma_chan *bam_dma_xlate(struct of_phandle_args *dma_spec,
+		struct of_dma *of)
+{
+	struct bam_device *bdev = container_of(of->of_dma_data,
+					struct bam_device, common);
+	unsigned int request;
+
+	if (dma_spec->args_count != 1)
+		return NULL;
+
+	request = dma_spec->args[0];
+	if (request >= bdev->num_channels)
+		return NULL;
+
+	return dma_get_slave_channel(&(bdev->channels[request].vc.chan));
+}
+
+/**
+ * bam_init
+ * @bdev: bam device
+ *
+ * Initialization helper for global bam registers
+ */
+static int bam_init(struct bam_device *bdev)
+{
+	u32 val;
+
+	/* read revision and configuration information */
+	if (!bdev->num_ees) {
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION));
+		bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK;
+	}
+
+	/* check that configured EE is within range */
+	if (bdev->ee >= bdev->num_ees)
+		return -EINVAL;
+
+	if (!bdev->num_channels) {
+		val = readl_relaxed(bam_addr(bdev, 0, BAM_NUM_PIPES));
+		bdev->num_channels = val & BAM_NUM_PIPES_MASK;
+	}
+
+	/* Reset BAM now if fully controlled locally */
+	if (!bdev->controlled_remotely && !bdev->powered_remotely)
+		bam_reset(bdev);
+
+	return 0;
+}
+
+static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan,
+	u32 index)
+{
+	bchan->id = index;
+	bchan->bdev = bdev;
+
+	vchan_init(&bchan->vc, &bdev->common);
+	bchan->vc.desc_free = bam_dma_free_desc;
+	INIT_LIST_HEAD(&bchan->desc_list);
+}
+
+static const struct of_device_id bam_of_match[] = {
+	{ .compatible = "qcom,bam-v1.3.0", .data = &bam_v1_3_reg_info },
+	{ .compatible = "qcom,bam-v1.4.0", .data = &bam_v1_4_reg_info },
+	{ .compatible = "qcom,bam-v1.7.0", .data = &bam_v1_7_reg_info },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, bam_of_match);
+
+static int bam_dma_probe(struct platform_device *pdev)
+{
+	struct bam_device *bdev;
+	const struct of_device_id *match;
+	int ret, i;
+
+	bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
+	if (!bdev)
+		return -ENOMEM;
+
+	bdev->dev = &pdev->dev;
+
+	match = of_match_node(bam_of_match, pdev->dev.of_node);
+	if (!match) {
+		dev_err(&pdev->dev, "Unsupported BAM module\n");
+		return -ENODEV;
+	}
+
+	bdev->layout = match->data;
+
+	bdev->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(bdev->regs))
+		return PTR_ERR(bdev->regs);
+
+	bdev->irq = platform_get_irq(pdev, 0);
+	if (bdev->irq < 0)
+		return bdev->irq;
+
+	ret = of_property_read_u32(pdev->dev.of_node, "qcom,ee", &bdev->ee);
+	if (ret) {
+		dev_err(bdev->dev, "Execution environment unspecified\n");
+		return ret;
+	}
+
+	bdev->controlled_remotely = of_property_read_bool(pdev->dev.of_node,
+						"qcom,controlled-remotely");
+	bdev->powered_remotely = of_property_read_bool(pdev->dev.of_node,
+						"qcom,powered-remotely");
+
+	if (bdev->controlled_remotely || bdev->powered_remotely)
+		bdev->bamclk = devm_clk_get_optional(bdev->dev, "bam_clk");
+	else
+		bdev->bamclk = devm_clk_get(bdev->dev, "bam_clk");
+
+	if (IS_ERR(bdev->bamclk))
+		return PTR_ERR(bdev->bamclk);
+
+	if (!bdev->bamclk) {
+		ret = of_property_read_u32(pdev->dev.of_node, "num-channels",
+					   &bdev->num_channels);
+		if (ret)
+			dev_err(bdev->dev, "num-channels unspecified in dt\n");
+
+		ret = of_property_read_u32(pdev->dev.of_node, "qcom,num-ees",
+					   &bdev->num_ees);
+		if (ret)
+			dev_err(bdev->dev, "num-ees unspecified in dt\n");
+	}
+
+	ret = clk_prepare_enable(bdev->bamclk);
+	if (ret) {
+		dev_err(bdev->dev, "failed to prepare/enable clock\n");
+		return ret;
+	}
+
+	ret = bam_init(bdev);
+	if (ret)
+		goto err_disable_clk;
+
+	tasklet_setup(&bdev->task, dma_tasklet);
+
+	bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
+				sizeof(*bdev->channels), GFP_KERNEL);
+
+	if (!bdev->channels) {
+		ret = -ENOMEM;
+		goto err_tasklet_kill;
+	}
+
+	/* allocate and initialize channels */
+	INIT_LIST_HEAD(&bdev->common.channels);
+
+	for (i = 0; i < bdev->num_channels; i++)
+		bam_channel_init(bdev, &bdev->channels[i], i);
+
+	ret = devm_request_irq(bdev->dev, bdev->irq, bam_dma_irq,
+			IRQF_TRIGGER_HIGH, "bam_dma", bdev);
+	if (ret)
+		goto err_bam_channel_exit;
+
+	/* set max dma segment size */
+	bdev->common.dev = bdev->dev;
+	ret = dma_set_max_seg_size(bdev->common.dev, BAM_FIFO_SIZE);
+	if (ret) {
+		dev_err(bdev->dev, "cannot set maximum segment size\n");
+		goto err_bam_channel_exit;
+	}
+
+	platform_set_drvdata(pdev, bdev);
+
+	/* set capabilities */
+	dma_cap_zero(bdev->common.cap_mask);
+	dma_cap_set(DMA_SLAVE, bdev->common.cap_mask);
+
+	/* initialize dmaengine apis */
+	bdev->common.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	bdev->common.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
+	bdev->common.src_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	bdev->common.dst_addr_widths = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	bdev->common.device_alloc_chan_resources = bam_alloc_chan;
+	bdev->common.device_free_chan_resources = bam_free_chan;
+	bdev->common.device_prep_slave_sg = bam_prep_slave_sg;
+	bdev->common.device_config = bam_slave_config;
+	bdev->common.device_pause = bam_pause;
+	bdev->common.device_resume = bam_resume;
+	bdev->common.device_terminate_all = bam_dma_terminate_all;
+	bdev->common.device_issue_pending = bam_issue_pending;
+	bdev->common.device_tx_status = bam_tx_status;
+	bdev->common.dev = bdev->dev;
+
+	ret = dma_async_device_register(&bdev->common);
+	if (ret) {
+		dev_err(bdev->dev, "failed to register dma async device\n");
+		goto err_bam_channel_exit;
+	}
+
+	ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
+					&bdev->common);
+	if (ret)
+		goto err_unregister_dma;
+
+	pm_runtime_irq_safe(&pdev->dev);
+	pm_runtime_set_autosuspend_delay(&pdev->dev, BAM_DMA_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(&pdev->dev);
+	pm_runtime_mark_last_busy(&pdev->dev);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	return 0;
+
+err_unregister_dma:
+	dma_async_device_unregister(&bdev->common);
+err_bam_channel_exit:
+	for (i = 0; i < bdev->num_channels; i++)
+		tasklet_kill(&bdev->channels[i].vc.task);
+err_tasklet_kill:
+	tasklet_kill(&bdev->task);
+err_disable_clk:
+	clk_disable_unprepare(bdev->bamclk);
+
+	return ret;
+}
+
+static int bam_dma_remove(struct platform_device *pdev)
+{
+	struct bam_device *bdev = platform_get_drvdata(pdev);
+	u32 i;
+
+	pm_runtime_force_suspend(&pdev->dev);
+
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&bdev->common);
+
+	/* mask all interrupts for this execution environment */
+	writel_relaxed(0, bam_addr(bdev, 0,  BAM_IRQ_SRCS_MSK_EE));
+
+	devm_free_irq(bdev->dev, bdev->irq, bdev);
+
+	for (i = 0; i < bdev->num_channels; i++) {
+		bam_dma_terminate_all(&bdev->channels[i].vc.chan);
+		tasklet_kill(&bdev->channels[i].vc.task);
+
+		if (!bdev->channels[i].fifo_virt)
+			continue;
+
+		dma_free_wc(bdev->dev, BAM_DESC_FIFO_SIZE,
+			    bdev->channels[i].fifo_virt,
+			    bdev->channels[i].fifo_phys);
+	}
+
+	tasklet_kill(&bdev->task);
+
+	clk_disable_unprepare(bdev->bamclk);
+
+	return 0;
+}
+
+static int __maybe_unused bam_dma_runtime_suspend(struct device *dev)
+{
+	struct bam_device *bdev = dev_get_drvdata(dev);
+
+	clk_disable(bdev->bamclk);
+
+	return 0;
+}
+
+static int __maybe_unused bam_dma_runtime_resume(struct device *dev)
+{
+	struct bam_device *bdev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(bdev->bamclk);
+	if (ret < 0) {
+		dev_err(dev, "clk_enable failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused bam_dma_suspend(struct device *dev)
+{
+	struct bam_device *bdev = dev_get_drvdata(dev);
+
+	pm_runtime_force_suspend(dev);
+	clk_unprepare(bdev->bamclk);
+
+	return 0;
+}
+
+static int __maybe_unused bam_dma_resume(struct device *dev)
+{
+	struct bam_device *bdev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare(bdev->bamclk);
+	if (ret)
+		return ret;
+
+	pm_runtime_force_resume(dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops bam_dma_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(bam_dma_suspend, bam_dma_resume)
+	SET_RUNTIME_PM_OPS(bam_dma_runtime_suspend, bam_dma_runtime_resume,
+				NULL)
+};
+
+static struct platform_driver bam_dma_driver = {
+	.probe = bam_dma_probe,
+	.remove = bam_dma_remove,
+	.driver = {
+		.name = "bam-dma-engine",
+		.pm = &bam_dma_pm_ops,
+		.of_match_table = bam_of_match,
+	},
+};
+
+module_platform_driver(bam_dma_driver);
+
+MODULE_AUTHOR("Andy Gross <agross@codeaurora.org>");
+MODULE_DESCRIPTION("QCOM BAM DMA engine driver");
+MODULE_LICENSE("GPL v2");