diff options
Diffstat (limited to 'drivers/dma/qcom_bam_dma.c')
| -rw-r--r-- | drivers/dma/qcom_bam_dma.c | 1111 |
1 files changed, 1111 insertions, 0 deletions
diff --git a/drivers/dma/qcom_bam_dma.c b/drivers/dma/qcom_bam_dma.c new file mode 100644 index 000000000000..82c923146e49 --- /dev/null +++ b/drivers/dma/qcom_bam_dma.c @@ -0,0 +1,1111 @@ +/* + * 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"); |