--- /dev/null
+/*
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 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.
+ *
+ */
+/*
+ * 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/clk.h>
+#include <linux/dmaengine.h>
+
+#include "dmaengine.h"
+#include "virt-dma.h"
+
+struct bam_desc_hw {
+ u32 addr; /* Buffer physical address */
+ u16 size; /* Buffer size in bytes */
+ u16 flags;
+};
+
+#define DESC_FLAG_INT BIT(15)
+#define DESC_FLAG_EOT BIT(14)
+#define DESC_FLAG_EOB BIT(13)
+
+struct bam_async_desc {
+ struct virt_dma_desc vd;
+
+ u32 num_desc;
+ u32 xfer_len;
+ struct bam_desc_hw *curr_desc;
+
+ enum dma_transfer_direction dir;
+ size_t length;
+ struct bam_desc_hw desc[0];
+};
+
+#define BAM_CTRL 0x0000
+#define BAM_REVISION 0x0004
+#define BAM_SW_REVISION 0x0080
+#define BAM_NUM_PIPES 0x003C
+#define BAM_TIMER 0x0040
+#define BAM_TIMER_CTRL 0x0044
+#define BAM_DESC_CNT_TRSHLD 0x0008
+#define BAM_IRQ_SRCS 0x000C
+#define BAM_IRQ_SRCS_MSK 0x0010
+#define BAM_IRQ_SRCS_UNMASKED 0x0030
+#define BAM_IRQ_STTS 0x0014
+#define BAM_IRQ_CLR 0x0018
+#define BAM_IRQ_EN 0x001C
+#define BAM_CNFG_BITS 0x007C
+#define BAM_IRQ_SRCS_EE(ee) (0x0800 + ((ee) * 0x80))
+#define BAM_IRQ_SRCS_MSK_EE(ee) (0x0804 + ((ee) * 0x80))
+#define BAM_P_CTRL(pipe) (0x1000 + ((pipe) * 0x1000))
+#define BAM_P_RST(pipe) (0x1004 + ((pipe) * 0x1000))
+#define BAM_P_HALT(pipe) (0x1008 + ((pipe) * 0x1000))
+#define BAM_P_IRQ_STTS(pipe) (0x1010 + ((pipe) * 0x1000))
+#define BAM_P_IRQ_CLR(pipe) (0x1014 + ((pipe) * 0x1000))
+#define BAM_P_IRQ_EN(pipe) (0x1018 + ((pipe) * 0x1000))
+#define BAM_P_EVNT_DEST_ADDR(pipe) (0x182C + ((pipe) * 0x1000))
+#define BAM_P_EVNT_REG(pipe) (0x1818 + ((pipe) * 0x1000))
+#define BAM_P_SW_OFSTS(pipe) (0x1800 + ((pipe) * 0x1000))
+#define BAM_P_DATA_FIFO_ADDR(pipe) (0x1824 + ((pipe) * 0x1000))
+#define BAM_P_DESC_FIFO_ADDR(pipe) (0x181C + ((pipe) * 0x1000))
+#define BAM_P_EVNT_TRSHLD(pipe) (0x1828 + ((pipe) * 0x1000))
+#define BAM_P_FIFO_SIZES(pipe) (0x1820 + ((pipe) * 0x1000))
+
+/* 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_MAX_DATA_SIZE (SZ_32K - 8)
+
+struct bam_chan {
+ struct virt_dma_chan vc;
+
+ struct bam_device *bdev;
+
+ /* configuration from device tree */
+ u32 id;
+
+ struct bam_async_desc *curr_txd; /* current running dma */
+
+ /* 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? */
+
+ 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 device_dma_parameters dma_parms;
+ struct bam_chan *channels;
+ u32 num_channels;
+
+ /* execution environment ID, from DT */
+ u32 ee;
+
+ struct clk *bamclk;
+ int irq;
+
+ /* dma start transaction tasklet */
+ struct tasklet_struct task;
+};
+
+/**
+ * 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, bdev->regs + BAM_P_RST(bchan->id));
+ writel_relaxed(0, bdev->regs + BAM_P_RST(bchan->id));
+
+ /* 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
+ *
+ * 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)),
+ bdev->regs + BAM_P_DESC_FIFO_ADDR(bchan->id));
+ writel_relaxed(BAM_DESC_FIFO_SIZE, bdev->regs +
+ BAM_P_FIFO_SIZES(bchan->id));
+
+ /* enable the per pipe interrupts, enable EOT, ERR, and INT irqs */
+ writel_relaxed(P_DEFAULT_IRQS_EN, bdev->regs + BAM_P_IRQ_EN(bchan->id));
+
+ /* unmask the specific pipe and EE combo */
+ val = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
+ val |= BIT(bchan->id);
+ writel_relaxed(val, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->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, bdev->regs + BAM_P_CTRL(bchan->id));
+
+ 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_writecombine(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;
+ }
+
+ 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;
+
+ vchan_free_chan_resources(to_virt_chan(chan));
+
+ if (bchan->curr_txd) {
+ dev_err(bchan->bdev->dev, "Cannot free busy channel\n");
+ return;
+ }
+
+ spin_lock_irqsave(&bchan->vc.lock, flags);
+ bam_reset_channel(bchan);
+ spin_unlock_irqrestore(&bchan->vc.lock, flags);
+
+ dma_free_writecombine(bdev->dev, BAM_DESC_FIFO_SIZE, bchan->fifo_virt,
+ bchan->fifo_phys);
+ bchan->fifo_virt = NULL;
+
+ /* mask irq for pipe/channel */
+ val = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
+ val &= ~BIT(bchan->id);
+ writel_relaxed(val, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
+
+ /* disable irq */
+ writel_relaxed(0, bdev->regs + BAM_P_IRQ_EN(bchan->id));
+}
+
+/**
+ * bam_slave_config - set slave configuration for channel
+ * @chan: dma channel
+ * @cfg: slave configuration
+ *
+ * Sets slave configuration for channel
+ *
+ */
+static void bam_slave_config(struct bam_chan *bchan,
+ struct dma_slave_config *cfg)
+{
+ memcpy(&bchan->slave, cfg, sizeof(*cfg));
+ bchan->reconfigure = 1;
+}
+
+/**
+ * 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_MAX_DATA_SIZE);
+
+ /* allocate enough room to accomodate the number of entries */
+ async_desc = kzalloc(sizeof(*async_desc) +
+ (num_alloc * sizeof(struct bam_desc_hw)), GFP_NOWAIT);
+
+ if (!async_desc)
+ goto err_out;
+
+ 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 {
+ desc->addr = sg_dma_address(sg) + curr_offset;
+
+ if (remainder > BAM_MAX_DATA_SIZE) {
+ desc->size = BAM_MAX_DATA_SIZE;
+ remainder -= BAM_MAX_DATA_SIZE;
+ curr_offset += BAM_MAX_DATA_SIZE;
+ } else {
+ desc->size = remainder;
+ remainder = 0;
+ }
+
+ async_desc->length += desc->size;
+ desc++;
+ } while (remainder > 0);
+ }
+
+ return vchan_tx_prep(&bchan->vc, &async_desc->vd, flags);
+
+err_out:
+ kfree(async_desc);
+ return NULL;
+}
+
+/**
+ * bam_dma_terminate_all - terminate all transactions on a channel
+ * @bchan: bam dma channel
+ *
+ * Dequeues and frees all transactions
+ * No callbacks are done
+ *
+ */
+static void bam_dma_terminate_all(struct bam_chan *bchan)
+{
+ unsigned long flag;
+ LIST_HEAD(head);
+
+ /* remove all transactions, including active transaction */
+ spin_lock_irqsave(&bchan->vc.lock, flag);
+ if (bchan->curr_txd) {
+ list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued);
+ bchan->curr_txd = NULL;
+ }
+
+ vchan_get_all_descriptors(&bchan->vc, &head);
+ spin_unlock_irqrestore(&bchan->vc.lock, flag);
+
+ vchan_dma_desc_free_list(&bchan->vc, &head);
+}
+
+/**
+ * bam_control - DMA device control
+ * @chan: dma channel
+ * @cmd: control cmd
+ * @arg: cmd argument
+ *
+ * Perform DMA control command
+ *
+ */
+static int bam_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct bam_chan *bchan = to_bam_chan(chan);
+ struct bam_device *bdev = bchan->bdev;
+ int ret = 0;
+ unsigned long flag;
+
+ switch (cmd) {
+ case DMA_PAUSE:
+ spin_lock_irqsave(&bchan->vc.lock, flag);
+ writel_relaxed(1, bdev->regs + BAM_P_HALT(bchan->id));
+ bchan->paused = 1;
+ spin_unlock_irqrestore(&bchan->vc.lock, flag);
+ break;
+
+ case DMA_RESUME:
+ spin_lock_irqsave(&bchan->vc.lock, flag);
+ writel_relaxed(0, bdev->regs + BAM_P_HALT(bchan->id));
+ bchan->paused = 0;
+ spin_unlock_irqrestore(&bchan->vc.lock, flag);
+ break;
+
+ case DMA_TERMINATE_ALL:
+ bam_dma_terminate_all(bchan);
+ break;
+
+ case DMA_SLAVE_CONFIG:
+ spin_lock_irqsave(&bchan->vc.lock, flag);
+ bam_slave_config(bchan, (struct dma_slave_config *)arg);
+ spin_unlock_irqrestore(&bchan->vc.lock, flag);
+ break;
+
+ default:
+ ret = -ENXIO;
+ break;
+ }
+
+ return ret;
+}
+
+/**
+ * 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;
+ unsigned long flags;
+ struct bam_async_desc *async_desc;
+
+ srcs = readl_relaxed(bdev->regs + BAM_IRQ_SRCS_EE(bdev->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(bdev->regs +
+ BAM_P_IRQ_STTS(i));
+
+ writel_relaxed(pipe_stts, bdev->regs +
+ BAM_P_IRQ_CLR(i));
+
+ spin_lock_irqsave(&bchan->vc.lock, flags);
+ async_desc = bchan->curr_txd;
+
+ if (async_desc) {
+ async_desc->num_desc -= async_desc->xfer_len;
+ async_desc->curr_desc += async_desc->xfer_len;
+ bchan->curr_txd = NULL;
+
+ /* manage FIFO */
+ bchan->head += async_desc->xfer_len;
+ bchan->head %= MAX_DESCRIPTORS;
+
+ /*
+ * 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);
+ }
+
+ 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;
+
+ srcs |= process_channel_irqs(bdev);
+
+ /* kick off tasklet to start next dma transfer */
+ if (srcs & P_IRQ)
+ tasklet_schedule(&bdev->task);
+
+ if (srcs & BAM_IRQ)
+ clr_mask = readl_relaxed(bdev->regs + BAM_IRQ_STTS);
+
+ /* don't allow reorder of the various accesses to the BAM registers */
+ mb();
+
+ writel_relaxed(clr_mask, bdev->regs + BAM_IRQ_CLR);
+
+ 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 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 if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie)
+ for (i = 0; i < bchan->curr_txd->num_desc; i++)
+ residue += bchan->curr_txd->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 (dir == DMA_DEV_TO_MEM)
+ maxburst = bchan->slave.src_maxburst;
+ else
+ maxburst = bchan->slave.dst_maxburst;
+
+ writel_relaxed(maxburst, bdev->regs + 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;
+ struct bam_desc_hw *desc;
+ struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt,
+ sizeof(struct bam_desc_hw));
+
+ lockdep_assert_held(&bchan->vc.lock);
+
+ if (!vd)
+ return;
+
+ list_del(&vd->node);
+
+ async_desc = container_of(vd, struct bam_async_desc, vd);
+ bchan->curr_txd = async_desc;
+
+ /* 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 = bchan->curr_txd->curr_desc;
+
+ if (async_desc->num_desc > MAX_DESCRIPTORS)
+ async_desc->xfer_len = MAX_DESCRIPTORS;
+ else
+ async_desc->xfer_len = async_desc->num_desc;
+
+ /* set INT on last descriptor */
+ desc[async_desc->xfer_len - 1].flags |= 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;
+
+ /* ensure descriptor writes and dma start not reordered */
+ wmb();
+ writel_relaxed(bchan->tail * sizeof(struct bam_desc_hw),
+ bdev->regs + BAM_P_EVNT_REG(bchan->id));
+}
+
+/**
+ * dma_tasklet - DMA IRQ tasklet
+ * @data: tasklet argument (bam controller structure)
+ *
+ * Sets up next DMA operation and then processes all completed transactions
+ */
+static void dma_tasklet(unsigned long data)
+{
+ struct bam_device *bdev = (struct bam_device *)data;
+ 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) && !bchan->curr_txd)
+ 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) && !bchan->curr_txd)
+ 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 */
+ val = readl_relaxed(bdev->regs + BAM_REVISION) >> NUM_EES_SHIFT;
+ val &= NUM_EES_MASK;
+
+ /* check that configured EE is within range */
+ if (bdev->ee >= val)
+ return -EINVAL;
+
+ val = readl_relaxed(bdev->regs + BAM_NUM_PIPES);
+ bdev->num_channels = val & BAM_NUM_PIPES_MASK;
+
+ /* s/w reset bam */
+ /* after reset all pipes are disabled and idle */
+ val = readl_relaxed(bdev->regs + BAM_CTRL);
+ val |= BAM_SW_RST;
+ writel_relaxed(val, bdev->regs + BAM_CTRL);
+ val &= ~BAM_SW_RST;
+ writel_relaxed(val, bdev->regs + BAM_CTRL);
+
+ /* make sure previous stores are visible before enabling BAM */
+ wmb();
+
+ /* enable bam */
+ val |= BAM_EN;
+ writel_relaxed(val, bdev->regs + BAM_CTRL);
+
+ /* set descriptor threshhold, start with 4 bytes */
+ writel_relaxed(DEFAULT_CNT_THRSHLD, bdev->regs + BAM_DESC_CNT_TRSHLD);
+
+ /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */
+ writel_relaxed(BAM_CNFG_BITS_DEFAULT, bdev->regs + BAM_CNFG_BITS);
+
+ /* enable irqs for errors */
+ writel_relaxed(BAM_ERROR_EN | BAM_HRESP_ERR_EN,
+ bdev->regs + BAM_IRQ_EN);
+
+ /* unmask global bam interrupt */
+ writel_relaxed(BAM_IRQ_MSK, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
+
+ 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;
+}
+
+static int bam_dma_probe(struct platform_device *pdev)
+{
+ struct bam_device *bdev;
+ struct resource *iores;
+ int ret, i;
+
+ bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL);
+ if (!bdev)
+ return -ENOMEM;
+
+ bdev->dev = &pdev->dev;
+
+ iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ bdev->regs = devm_ioremap_resource(&pdev->dev, iores);
+ 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->bamclk = devm_clk_get(bdev->dev, "bam_clk");
+ if (IS_ERR(bdev->bamclk))
+ return PTR_ERR(bdev->bamclk);
+
+ 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_init(&bdev->task, dma_tasklet, (unsigned long)bdev);
+
+ bdev->channels = devm_kcalloc(bdev->dev, bdev->num_channels,
+ sizeof(*bdev->channels), GFP_KERNEL);
+
+ if (!bdev->channels) {
+ ret = -ENOMEM;
+ goto err_disable_clk;
+ }
+
+ /* 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_disable_clk;
+
+ /* set max dma segment size */
+ bdev->common.dev = bdev->dev;
+ bdev->common.dev->dma_parms = &bdev->dma_parms;
+ ret = dma_set_max_seg_size(bdev->common.dev, BAM_MAX_DATA_SIZE);
+ if (ret) {
+ dev_err(bdev->dev, "cannot set maximum segment size\n");
+ goto err_disable_clk;
+ }
+
+ 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.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_control = bam_control;
+ 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_disable_clk;
+ }
+
+ ret = of_dma_controller_register(pdev->dev.of_node, bam_dma_xlate,
+ &bdev->common);
+ if (ret)
+ goto err_unregister_dma;
+
+ return 0;
+
+err_unregister_dma:
+ dma_async_device_unregister(&bdev->common);
+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;
+
+ of_dma_controller_free(pdev->dev.of_node);
+ dma_async_device_unregister(&bdev->common);
+
+ /* mask all interrupts for this execution environment */
+ writel_relaxed(0, bdev->regs + BAM_IRQ_SRCS_MSK_EE(bdev->ee));
+
+ devm_free_irq(bdev->dev, bdev->irq, bdev);
+
+ for (i = 0; i < bdev->num_channels; i++) {
+ bam_dma_terminate_all(&bdev->channels[i]);
+ tasklet_kill(&bdev->channels[i].vc.task);
+
+ dma_free_writecombine(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 const struct of_device_id bam_of_match[] = {
+ { .compatible = "qcom,bam-v1.4.0", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, bam_of_match);
+
+static struct platform_driver bam_dma_driver = {
+ .probe = bam_dma_probe,
+ .remove = bam_dma_remove,
+ .driver = {
+ .name = "bam-dma-engine",
+ .owner = THIS_MODULE,
+ .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");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff