diff options
Diffstat (limited to 'drivers/dma/altera-msgdma.c')
| -rw-r--r-- | drivers/dma/altera-msgdma.c | 927 |
1 files changed, 927 insertions, 0 deletions
diff --git a/drivers/dma/altera-msgdma.c b/drivers/dma/altera-msgdma.c new file mode 100644 index 000000000000..32905d5606ac --- /dev/null +++ b/drivers/dma/altera-msgdma.c @@ -0,0 +1,927 @@ +/* + * DMA driver for Altera mSGDMA IP core + * + * Copyright (C) 2017 Stefan Roese <sr@denx.de> + * + * Based on drivers/dma/xilinx/zynqmp_dma.c, which is: + * Copyright (C) 2016 Xilinx, Inc. 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 as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmapool.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "dmaengine.h" + +#define MSGDMA_MAX_TRANS_LEN U32_MAX +#define MSGDMA_DESC_NUM 1024 + +/** + * struct msgdma_extended_desc - implements an extended descriptor + * @read_addr_lo: data buffer source address low bits + * @write_addr_lo: data buffer destination address low bits + * @len: the number of bytes to transfer per descriptor + * @burst_seq_num: bit 31:24 write burst + * bit 23:16 read burst + * bit 15:00 sequence number + * @stride: bit 31:16 write stride + * bit 15:00 read stride + * @read_addr_hi: data buffer source address high bits + * @write_addr_hi: data buffer destination address high bits + * @control: characteristics of the transfer + */ +struct msgdma_extended_desc { + u32 read_addr_lo; + u32 write_addr_lo; + u32 len; + u32 burst_seq_num; + u32 stride; + u32 read_addr_hi; + u32 write_addr_hi; + u32 control; +}; + +/* mSGDMA descriptor control field bit definitions */ +#define MSGDMA_DESC_CTL_SET_CH(x) ((x) & 0xff) +#define MSGDMA_DESC_CTL_GEN_SOP BIT(8) +#define MSGDMA_DESC_CTL_GEN_EOP BIT(9) +#define MSGDMA_DESC_CTL_PARK_READS BIT(10) +#define MSGDMA_DESC_CTL_PARK_WRITES BIT(11) +#define MSGDMA_DESC_CTL_END_ON_EOP BIT(12) +#define MSGDMA_DESC_CTL_END_ON_LEN BIT(13) +#define MSGDMA_DESC_CTL_TR_COMP_IRQ BIT(14) +#define MSGDMA_DESC_CTL_EARLY_IRQ BIT(15) +#define MSGDMA_DESC_CTL_TR_ERR_IRQ GENMASK(23, 16) +#define MSGDMA_DESC_CTL_EARLY_DONE BIT(24) + +/* + * Writing "1" the "go" bit commits the entire descriptor into the + * descriptor FIFO(s) + */ +#define MSGDMA_DESC_CTL_GO BIT(31) + +/* Tx buffer control flags */ +#define MSGDMA_DESC_CTL_TX_FIRST (MSGDMA_DESC_CTL_GEN_SOP | \ + MSGDMA_DESC_CTL_TR_ERR_IRQ | \ + MSGDMA_DESC_CTL_GO) + +#define MSGDMA_DESC_CTL_TX_MIDDLE (MSGDMA_DESC_CTL_TR_ERR_IRQ | \ + MSGDMA_DESC_CTL_GO) + +#define MSGDMA_DESC_CTL_TX_LAST (MSGDMA_DESC_CTL_GEN_EOP | \ + MSGDMA_DESC_CTL_TR_COMP_IRQ | \ + MSGDMA_DESC_CTL_TR_ERR_IRQ | \ + MSGDMA_DESC_CTL_GO) + +#define MSGDMA_DESC_CTL_TX_SINGLE (MSGDMA_DESC_CTL_GEN_SOP | \ + MSGDMA_DESC_CTL_GEN_EOP | \ + MSGDMA_DESC_CTL_TR_COMP_IRQ | \ + MSGDMA_DESC_CTL_TR_ERR_IRQ | \ + MSGDMA_DESC_CTL_GO) + +#define MSGDMA_DESC_CTL_RX_SINGLE (MSGDMA_DESC_CTL_END_ON_EOP | \ + MSGDMA_DESC_CTL_END_ON_LEN | \ + MSGDMA_DESC_CTL_TR_COMP_IRQ | \ + MSGDMA_DESC_CTL_EARLY_IRQ | \ + MSGDMA_DESC_CTL_TR_ERR_IRQ | \ + MSGDMA_DESC_CTL_GO) + +/* mSGDMA extended descriptor stride definitions */ +#define MSGDMA_DESC_STRIDE_RD 0x00000001 +#define MSGDMA_DESC_STRIDE_WR 0x00010000 +#define MSGDMA_DESC_STRIDE_RW 0x00010001 + +/* mSGDMA dispatcher control and status register map */ +#define MSGDMA_CSR_STATUS 0x00 /* Read / Clear */ +#define MSGDMA_CSR_CONTROL 0x04 /* Read / Write */ +#define MSGDMA_CSR_RW_FILL_LEVEL 0x08 /* 31:16 - write fill level */ + /* 15:00 - read fill level */ +#define MSGDMA_CSR_RESP_FILL_LEVEL 0x0c /* response FIFO fill level */ +#define MSGDMA_CSR_RW_SEQ_NUM 0x10 /* 31:16 - write seq number */ + /* 15:00 - read seq number */ + +/* mSGDMA CSR status register bit definitions */ +#define MSGDMA_CSR_STAT_BUSY BIT(0) +#define MSGDMA_CSR_STAT_DESC_BUF_EMPTY BIT(1) +#define MSGDMA_CSR_STAT_DESC_BUF_FULL BIT(2) +#define MSGDMA_CSR_STAT_RESP_BUF_EMPTY BIT(3) +#define MSGDMA_CSR_STAT_RESP_BUF_FULL BIT(4) +#define MSGDMA_CSR_STAT_STOPPED BIT(5) +#define MSGDMA_CSR_STAT_RESETTING BIT(6) +#define MSGDMA_CSR_STAT_STOPPED_ON_ERR BIT(7) +#define MSGDMA_CSR_STAT_STOPPED_ON_EARLY BIT(8) +#define MSGDMA_CSR_STAT_IRQ BIT(9) +#define MSGDMA_CSR_STAT_MASK GENMASK(9, 0) +#define MSGDMA_CSR_STAT_MASK_WITHOUT_IRQ GENMASK(8, 0) + +#define DESC_EMPTY (MSGDMA_CSR_STAT_DESC_BUF_EMPTY | \ + MSGDMA_CSR_STAT_RESP_BUF_EMPTY) + +/* mSGDMA CSR control register bit definitions */ +#define MSGDMA_CSR_CTL_STOP BIT(0) +#define MSGDMA_CSR_CTL_RESET BIT(1) +#define MSGDMA_CSR_CTL_STOP_ON_ERR BIT(2) +#define MSGDMA_CSR_CTL_STOP_ON_EARLY BIT(3) +#define MSGDMA_CSR_CTL_GLOBAL_INTR BIT(4) +#define MSGDMA_CSR_CTL_STOP_DESCS BIT(5) + +/* mSGDMA CSR fill level bits */ +#define MSGDMA_CSR_WR_FILL_LEVEL_GET(v) (((v) & 0xffff0000) >> 16) +#define MSGDMA_CSR_RD_FILL_LEVEL_GET(v) ((v) & 0x0000ffff) +#define MSGDMA_CSR_RESP_FILL_LEVEL_GET(v) ((v) & 0x0000ffff) + +#define MSGDMA_CSR_SEQ_NUM_GET(v) (((v) & 0xffff0000) >> 16) + +/* mSGDMA response register map */ +#define MSGDMA_RESP_BYTES_TRANSFERRED 0x00 +#define MSGDMA_RESP_STATUS 0x04 + +/* mSGDMA response register bit definitions */ +#define MSGDMA_RESP_EARLY_TERM BIT(8) +#define MSGDMA_RESP_ERR_MASK 0xff + +/** + * struct msgdma_sw_desc - implements a sw descriptor + * @async_tx: support for the async_tx api + * @hw_desc: assosiated HW descriptor + * @free_list: node of the free SW descriprots list + */ +struct msgdma_sw_desc { + struct dma_async_tx_descriptor async_tx; + struct msgdma_extended_desc hw_desc; + struct list_head node; + struct list_head tx_list; +}; + +/** + * struct msgdma_device - DMA device structure + */ +struct msgdma_device { + spinlock_t lock; + struct device *dev; + struct tasklet_struct irq_tasklet; + struct list_head pending_list; + struct list_head free_list; + struct list_head active_list; + struct list_head done_list; + u32 desc_free_cnt; + bool idle; + + struct dma_device dmadev; + struct dma_chan dmachan; + dma_addr_t hw_desq; + struct msgdma_sw_desc *sw_desq; + unsigned int npendings; + + struct dma_slave_config slave_cfg; + + int irq; + + /* mSGDMA controller */ + void __iomem *csr; + + /* mSGDMA descriptors */ + void __iomem *desc; + + /* mSGDMA response */ + void __iomem *resp; +}; + +#define to_mdev(chan) container_of(chan, struct msgdma_device, dmachan) +#define tx_to_desc(tx) container_of(tx, struct msgdma_sw_desc, async_tx) + +/** + * msgdma_get_descriptor - Get the sw descriptor from the pool + * @mdev: Pointer to the Altera mSGDMA device structure + * + * Return: The sw descriptor + */ +static struct msgdma_sw_desc *msgdma_get_descriptor(struct msgdma_device *mdev) +{ + struct msgdma_sw_desc *desc; + + spin_lock_bh(&mdev->lock); + desc = list_first_entry(&mdev->free_list, struct msgdma_sw_desc, node); + list_del(&desc->node); + spin_unlock_bh(&mdev->lock); + + INIT_LIST_HEAD(&desc->tx_list); + + return desc; +} + +/** + * msgdma_free_descriptor - Issue pending transactions + * @mdev: Pointer to the Altera mSGDMA device structure + * @desc: Transaction descriptor pointer + */ +static void msgdma_free_descriptor(struct msgdma_device *mdev, + struct msgdma_sw_desc *desc) +{ + struct msgdma_sw_desc *child, *next; + + mdev->desc_free_cnt++; + list_add_tail(&desc->node, &mdev->free_list); + list_for_each_entry_safe(child, next, &desc->tx_list, node) { + mdev->desc_free_cnt++; + list_move_tail(&child->node, &mdev->free_list); + } +} + +/** + * msgdma_free_desc_list - Free descriptors list + * @mdev: Pointer to the Altera mSGDMA device structure + * @list: List to parse and delete the descriptor + */ +static void msgdma_free_desc_list(struct msgdma_device *mdev, + struct list_head *list) +{ + struct msgdma_sw_desc *desc, *next; + + list_for_each_entry_safe(desc, next, list, node) + msgdma_free_descriptor(mdev, desc); +} + +/** + * msgdma_desc_config - Configure the descriptor + * @desc: Hw descriptor pointer + * @dst: Destination buffer address + * @src: Source buffer address + * @len: Transfer length + */ +static void msgdma_desc_config(struct msgdma_extended_desc *desc, + dma_addr_t dst, dma_addr_t src, size_t len, + u32 stride) +{ + /* Set lower 32bits of src & dst addresses in the descriptor */ + desc->read_addr_lo = lower_32_bits(src); + desc->write_addr_lo = lower_32_bits(dst); + + /* Set upper 32bits of src & dst addresses in the descriptor */ + desc->read_addr_hi = upper_32_bits(src); + desc->write_addr_hi = upper_32_bits(dst); + + desc->len = len; + desc->stride = stride; + desc->burst_seq_num = 0; /* 0 will result in max burst length */ + + /* + * Don't set interrupt on xfer end yet, this will be done later + * for the "last" descriptor + */ + desc->control = MSGDMA_DESC_CTL_TR_ERR_IRQ | MSGDMA_DESC_CTL_GO | + MSGDMA_DESC_CTL_END_ON_LEN; +} + +/** + * msgdma_desc_config_eod - Mark the descriptor as end descriptor + * @desc: Hw descriptor pointer + */ +static void msgdma_desc_config_eod(struct msgdma_extended_desc *desc) +{ + desc->control |= MSGDMA_DESC_CTL_TR_COMP_IRQ; +} + +/** + * msgdma_tx_submit - Submit DMA transaction + * @tx: Async transaction descriptor pointer + * + * Return: cookie value + */ +static dma_cookie_t msgdma_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct msgdma_device *mdev = to_mdev(tx->chan); + struct msgdma_sw_desc *new; + dma_cookie_t cookie; + + new = tx_to_desc(tx); + spin_lock_bh(&mdev->lock); + cookie = dma_cookie_assign(tx); + + list_add_tail(&new->node, &mdev->pending_list); + spin_unlock_bh(&mdev->lock); + + return cookie; +} + +/** + * msgdma_prep_memcpy - prepare descriptors for memcpy transaction + * @dchan: DMA channel + * @dma_dst: Destination buffer address + * @dma_src: Source buffer address + * @len: Transfer length + * @flags: transfer ack flags + * + * Return: Async transaction descriptor on success and NULL on failure + */ +static struct dma_async_tx_descriptor * +msgdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst, + dma_addr_t dma_src, size_t len, ulong flags) +{ + struct msgdma_device *mdev = to_mdev(dchan); + struct msgdma_sw_desc *new, *first = NULL; + struct msgdma_extended_desc *desc; + size_t copy; + u32 desc_cnt; + + desc_cnt = DIV_ROUND_UP(len, MSGDMA_MAX_TRANS_LEN); + + spin_lock_bh(&mdev->lock); + if (desc_cnt > mdev->desc_free_cnt) { + spin_unlock_bh(&mdev->lock); + dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev); + return NULL; + } + mdev->desc_free_cnt -= desc_cnt; + spin_unlock_bh(&mdev->lock); + + do { + /* Allocate and populate the descriptor */ + new = msgdma_get_descriptor(mdev); + + copy = min_t(size_t, len, MSGDMA_MAX_TRANS_LEN); + desc = &new->hw_desc; + msgdma_desc_config(desc, dma_dst, dma_src, copy, + MSGDMA_DESC_STRIDE_RW); + len -= copy; + dma_src += copy; + dma_dst += copy; + if (!first) + first = new; + else + list_add_tail(&new->node, &first->tx_list); + } while (len); + + msgdma_desc_config_eod(desc); + async_tx_ack(&first->async_tx); + first->async_tx.flags = flags; + + return &first->async_tx; +} + +/** + * msgdma_prep_slave_sg - prepare descriptors for a slave sg transaction + * + * @dchan: DMA channel + * @sgl: Destination scatter list + * @sg_len: Number of entries in destination scatter list + * @dir: DMA transfer direction + * @flags: transfer ack flags + * @context: transfer context (unused) + */ +static struct dma_async_tx_descriptor * +msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction dir, + unsigned long flags, void *context) + +{ + struct msgdma_device *mdev = to_mdev(dchan); + struct dma_slave_config *cfg = &mdev->slave_cfg; + struct msgdma_sw_desc *new, *first = NULL; + void *desc = NULL; + size_t len, avail; + dma_addr_t dma_dst, dma_src; + u32 desc_cnt = 0, i; + struct scatterlist *sg; + u32 stride; + + for_each_sg(sgl, sg, sg_len, i) + desc_cnt += DIV_ROUND_UP(sg_dma_len(sg), MSGDMA_MAX_TRANS_LEN); + + spin_lock_bh(&mdev->lock); + if (desc_cnt > mdev->desc_free_cnt) { + spin_unlock_bh(&mdev->lock); + dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev); + return NULL; + } + mdev->desc_free_cnt -= desc_cnt; + spin_unlock_bh(&mdev->lock); + + avail = sg_dma_len(sgl); + + /* Run until we are out of scatterlist entries */ + while (true) { + /* Allocate and populate the descriptor */ + new = msgdma_get_descriptor(mdev); + + desc = &new->hw_desc; + len = min_t(size_t, avail, MSGDMA_MAX_TRANS_LEN); + + if (dir == DMA_MEM_TO_DEV) { + dma_src = sg_dma_address(sgl) + sg_dma_len(sgl) - avail; + dma_dst = cfg->dst_addr; + stride = MSGDMA_DESC_STRIDE_RD; + } else { + dma_src = cfg->src_addr; + dma_dst = sg_dma_address(sgl) + sg_dma_len(sgl) - avail; + stride = MSGDMA_DESC_STRIDE_WR; + } + msgdma_desc_config(desc, dma_dst, dma_src, len, stride); + avail -= len; + + if (!first) + first = new; + else + list_add_tail(&new->node, &first->tx_list); + + /* Fetch the next scatterlist entry */ + if (avail == 0) { + if (sg_len == 0) + break; + sgl = sg_next(sgl); + if (sgl == NULL) + break; + sg_len--; + avail = sg_dma_len(sgl); + } + } + + msgdma_desc_config_eod(desc); + first->async_tx.flags = flags; + + return &first->async_tx; +} + +static int msgdma_dma_config(struct dma_chan *dchan, + struct dma_slave_config *config) +{ + struct msgdma_device *mdev = to_mdev(dchan); + + memcpy(&mdev->slave_cfg, config, sizeof(*config)); + + return 0; +} + +static void msgdma_reset(struct msgdma_device *mdev) +{ + u32 val; + int ret; + + /* Reset mSGDMA */ + iowrite32(MSGDMA_CSR_STAT_MASK, mdev->csr + MSGDMA_CSR_STATUS); + iowrite32(MSGDMA_CSR_CTL_RESET, mdev->csr + MSGDMA_CSR_CONTROL); + + ret = readl_poll_timeout(mdev->csr + MSGDMA_CSR_STATUS, val, + (val & MSGDMA_CSR_STAT_RESETTING) == 0, + 1, 10000); + if (ret) + dev_err(mdev->dev, "DMA channel did not reset\n"); + + /* Clear all status bits */ + iowrite32(MSGDMA_CSR_STAT_MASK, mdev->csr + MSGDMA_CSR_STATUS); + + /* Enable the DMA controller including interrupts */ + iowrite32(MSGDMA_CSR_CTL_STOP_ON_ERR | MSGDMA_CSR_CTL_STOP_ON_EARLY | + MSGDMA_CSR_CTL_GLOBAL_INTR, mdev->csr + MSGDMA_CSR_CONTROL); + + mdev->idle = true; +}; + +static void msgdma_copy_one(struct msgdma_device *mdev, + struct msgdma_sw_desc *desc) +{ + void __iomem *hw_desc = mdev->desc; + + /* + * Check if the DESC FIFO it not full. If its full, we need to wait + * for at least one entry to become free again + */ + while (ioread32(mdev->csr + MSGDMA_CSR_STATUS) & + MSGDMA_CSR_STAT_DESC_BUF_FULL) + mdelay(1); + + /* + * The descriptor needs to get copied into the descriptor FIFO + * of the DMA controller. The descriptor will get flushed to the + * FIFO, once the last word (control word) is written. Since we + * are not 100% sure that memcpy() writes all word in the "correct" + * oder (address from low to high) on all architectures, we make + * sure this control word is written last by single coding it and + * adding some write-barriers here. + */ + memcpy((void __force *)hw_desc, &desc->hw_desc, + sizeof(desc->hw_desc) - sizeof(u32)); + + /* Write control word last to flush this descriptor into the FIFO */ + mdev->idle = false; + wmb(); + iowrite32(desc->hw_desc.control, hw_desc + + offsetof(struct msgdma_extended_desc, control)); + wmb(); +} + +/** + * msgdma_copy_desc_to_fifo - copy descriptor(s) into controller FIFO + * @mdev: Pointer to the Altera mSGDMA device structure + * @desc: Transaction descriptor pointer + */ +static void msgdma_copy_desc_to_fifo(struct msgdma_device *mdev, + struct msgdma_sw_desc *desc) +{ + struct msgdma_sw_desc *sdesc, *next; + + msgdma_copy_one(mdev, desc); + + list_for_each_entry_safe(sdesc, next, &desc->tx_list, node) + msgdma_copy_one(mdev, sdesc); +} + +/** + * msgdma_start_transfer - Initiate the new transfer + * @mdev: Pointer to the Altera mSGDMA device structure + */ +static void msgdma_start_transfer(struct msgdma_device *mdev) +{ + struct msgdma_sw_desc *desc; + + if (!mdev->idle) + return; + + desc = list_first_entry_or_null(&mdev->pending_list, + struct msgdma_sw_desc, node); + if (!desc) + return; + + list_splice_tail_init(&mdev->pending_list, &mdev->active_list); + msgdma_copy_desc_to_fifo(mdev, desc); +} + +/** + * msgdma_issue_pending - Issue pending transactions + * @chan: DMA channel pointer + */ +static void msgdma_issue_pending(struct dma_chan *chan) +{ + struct msgdma_device *mdev = to_mdev(chan); + + spin_lock_bh(&mdev->lock); + msgdma_start_transfer(mdev); + spin_unlock_bh(&mdev->lock); +} + +/** + * msgdma_chan_desc_cleanup - Cleanup the completed descriptors + * @mdev: Pointer to the Altera mSGDMA device structure + */ +static void msgdma_chan_desc_cleanup(struct msgdma_device *mdev) +{ + struct msgdma_sw_desc *desc, *next; + + list_for_each_entry_safe(desc, next, &mdev->done_list, node) { + dma_async_tx_callback callback; + void *callback_param; + + list_del(&desc->node); + + callback = desc->async_tx.callback; + callback_param = desc->async_tx.callback_param; + if (callback) { + spin_unlock(&mdev->lock); + callback(callback_param); + spin_lock(&mdev->lock); + } + + /* Run any dependencies, then free the descriptor */ + msgdma_free_descriptor(mdev, desc); + } +} + +/** + * msgdma_complete_descriptor - Mark the active descriptor as complete + * @mdev: Pointer to the Altera mSGDMA device structure + */ +static void msgdma_complete_descriptor(struct msgdma_device *mdev) +{ + struct msgdma_sw_desc *desc; + + desc = list_first_entry_or_null(&mdev->active_list, + struct msgdma_sw_desc, node); + if (!desc) + return; + list_del(&desc->node); + dma_cookie_complete(&desc->async_tx); + list_add_tail(&desc->node, &mdev->done_list); +} + +/** + * msgdma_free_descriptors - Free channel descriptors + * @mdev: Pointer to the Altera mSGDMA device structure + */ +static void msgdma_free_descriptors(struct msgdma_device *mdev) +{ + msgdma_free_desc_list(mdev, &mdev->active_list); + msgdma_free_desc_list(mdev, &mdev->pending_list); + msgdma_free_desc_list(mdev, &mdev->done_list); +} + +/** + * msgdma_free_chan_resources - Free channel resources + * @dchan: DMA channel pointer + */ +static void msgdma_free_chan_resources(struct dma_chan *dchan) +{ + struct msgdma_device *mdev = to_mdev(dchan); + + spin_lock_bh(&mdev->lock); + msgdma_free_descriptors(mdev); + spin_unlock_bh(&mdev->lock); + kfree(mdev->sw_desq); +} + +/** + * msgdma_alloc_chan_resources - Allocate channel resources + * @dchan: DMA channel + * + * Return: Number of descriptors on success and failure value on error + */ +static int msgdma_alloc_chan_resources(struct dma_chan *dchan) +{ + struct msgdma_device *mdev = to_mdev(dchan); + struct msgdma_sw_desc *desc; + int i; + + mdev->sw_desq = kcalloc(MSGDMA_DESC_NUM, sizeof(*desc), GFP_NOWAIT); + if (!mdev->sw_desq) + return -ENOMEM; + + mdev->idle = true; + mdev->desc_free_cnt = MSGDMA_DESC_NUM; + + INIT_LIST_HEAD(&mdev->free_list); + + for (i = 0; i < MSGDMA_DESC_NUM; i++) { + desc = mdev->sw_desq + i; + dma_async_tx_descriptor_init(&desc->async_tx, &mdev->dmachan); + desc->async_tx.tx_submit = msgdma_tx_submit; + list_add_tail(&desc->node, &mdev->free_list); + } + + return MSGDMA_DESC_NUM; +} + +/** + * msgdma_tasklet - Schedule completion tasklet + * @data: Pointer to the Altera sSGDMA channel structure + */ +static void msgdma_tasklet(unsigned long data) +{ + struct msgdma_device *mdev = (struct msgdma_device *)data; + u32 count; + u32 __maybe_unused size; + u32 __maybe_unused status; + + spin_lock(&mdev->lock); + + /* Read number of responses that are available */ + count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL); + dev_dbg(mdev->dev, "%s (%d): response count=%d\n", + __func__, __LINE__, count); + + while (count--) { + /* + * Read both longwords to purge this response from the FIFO + * On Avalon-MM implementations, size and status do not + * have any real values, like transferred bytes or error + * bits. So we need to just drop these values. + */ + size = ioread32(mdev->resp + MSGDMA_RESP_BYTES_TRANSFERRED); + status = ioread32(mdev->resp - MSGDMA_RESP_STATUS); + + msgdma_complete_descriptor(mdev); + msgdma_chan_desc_cleanup(mdev); + } + + spin_unlock(&mdev->lock); +} + +/** + * msgdma_irq_handler - Altera mSGDMA Interrupt handler + * @irq: IRQ number + * @data: Pointer to the Altera mSGDMA device structure + * + * Return: IRQ_HANDLED/IRQ_NONE + */ +static irqreturn_t msgdma_irq_handler(int irq, void *data) +{ + struct msgdma_device *mdev = data; + u32 status; + + status = ioread32(mdev->csr + MSGDMA_CSR_STATUS); + if ((status & MSGDMA_CSR_STAT_BUSY) == 0) { + /* Start next transfer if the DMA controller is idle */ + spin_lock(&mdev->lock); + mdev->idle = true; + msgdma_start_transfer(mdev); + spin_unlock(&mdev->lock); + } + + tasklet_schedule(&mdev->irq_tasklet); + + /* Clear interrupt in mSGDMA controller */ + iowrite32(MSGDMA_CSR_STAT_IRQ, mdev->csr + MSGDMA_CSR_STATUS); + + return IRQ_HANDLED; +} + +/** + * msgdma_chan_remove - Channel remove function + * @mdev: Pointer to the Altera mSGDMA device structure + */ +static void msgdma_dev_remove(struct msgdma_device *mdev) +{ + if (!mdev) + return; + + devm_free_irq(mdev->dev, mdev->irq, mdev); + tasklet_kill(&mdev->irq_tasklet); + list_del(&mdev->dmachan.device_node); +} + +static int request_and_map(struct platform_device *pdev, const char *name, + struct resource **res, void __iomem **ptr) +{ + struct resource *region; + struct device *device = &pdev->dev; + + *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name); + if (*res == NULL) { + dev_err(device, "resource %s not defined\n", name); + return -ENODEV; + } + + region = devm_request_mem_region(device, (*res)->start, + resource_size(*res), dev_name(device)); + if (region == NULL) { + dev_err(device, "unable to request %s\n", name); + return -EBUSY; + } + + *ptr = devm_ioremap_nocache(device, region->start, + resource_size(region)); + if (*ptr == NULL) { + dev_err(device, "ioremap_nocache of %s failed!", name); + return -ENOMEM; + } + + return 0; +} + +/** + * msgdma_probe - Driver probe function + * @pdev: Pointer to the platform_device structure + * + * Return: '0' on success and failure value on error + */ +static int msgdma_probe(struct platform_device *pdev) +{ + struct msgdma_device *mdev; + struct dma_device *dma_dev; + struct resource *dma_res; + int ret; + + mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_NOWAIT); + if (!mdev) + return -ENOMEM; + + mdev->dev = &pdev->dev; + + /* Map CSR space */ + ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr); + if (ret) + return ret; + + /* Map (extended) descriptor space */ + ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc); + if (ret) + return ret; + + /* Map response space */ + ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp); + if (ret) + return ret; + + platform_set_drvdata(pdev, mdev); + + /* Get interrupt nr from platform data */ + mdev->irq = platform_get_irq(pdev, 0); + if (mdev->irq < 0) + return -ENXIO; + + ret = devm_request_irq(&pdev->dev, mdev->irq, msgdma_irq_handler, + 0, dev_name(&pdev->dev), mdev); + if (ret) + return ret; + + tasklet_init(&mdev->irq_tasklet, msgdma_tasklet, (unsigned long)mdev); + + dma_cookie_init(&mdev->dmachan); + + spin_lock_init(&mdev->lock); + + INIT_LIST_HEAD(&mdev->active_list); + INIT_LIST_HEAD(&mdev->pending_list); + INIT_LIST_HEAD(&mdev->done_list); + INIT_LIST_HEAD(&mdev->free_list); + + dma_dev = &mdev->dmadev; + + /* Set DMA capabilities */ + dma_cap_zero(dma_dev->cap_mask); + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); + dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); + + dma_dev->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dma_dev->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dma_dev->directions = BIT(DMA_MEM_TO_DEV) | BIT(DMA_DEV_TO_MEM) | + BIT(DMA_MEM_TO_MEM); + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_DESCRIPTOR; + + /* Init DMA link list */ + INIT_LIST_HEAD(&dma_dev->channels); + + /* Set base routines */ + dma_dev->device_tx_status = dma_cookie_status; + dma_dev->device_issue_pending = msgdma_issue_pending; + dma_dev->dev = &pdev->dev; + + dma_dev->copy_align = DMAENGINE_ALIGN_4_BYTES; + dma_dev->device_prep_dma_memcpy = msgdma_prep_memcpy; + dma_dev->device_prep_slave_sg = msgdma_prep_slave_sg; + dma_dev->device_config = msgdma_dma_config; + + dma_dev->device_alloc_chan_resources = msgdma_alloc_chan_resources; + dma_dev->device_free_chan_resources = msgdma_free_chan_resources; + + mdev->dmachan.device = dma_dev; + list_add_tail(&mdev->dmachan.device_node, &dma_dev->channels); + + /* Set DMA mask to 64 bits */ + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); + if (ret) { + dev_warn(&pdev->dev, "unable to set coherent mask to 64"); + ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + if (ret) + goto fail; + } + + msgdma_reset(mdev); + + ret = dma_async_device_register(dma_dev); + if (ret) + goto fail; + + dev_notice(&pdev->dev, "Altera mSGDMA driver probe success\n"); + + return 0; + +fail: + msgdma_dev_remove(mdev); + + return ret; +} + +/** + * msgdma_dma_remove - Driver remove function + * @pdev: Pointer to the platform_device structure + * + * Return: Always '0' + */ +static int msgdma_remove(struct platform_device *pdev) +{ + struct msgdma_device *mdev = platform_get_drvdata(pdev); + + dma_async_device_unregister(&mdev->dmadev); + msgdma_dev_remove(mdev); + + dev_notice(&pdev->dev, "Altera mSGDMA driver removed\n"); + + return 0; +} + +static struct platform_driver msgdma_driver = { + .driver = { + .name = "altera-msgdma", + }, + .probe = msgdma_probe, + .remove = msgdma_remove, +}; + +module_platform_driver(msgdma_driver); + +MODULE_ALIAS("platform:altera-msgdma"); +MODULE_DESCRIPTION("Altera mSGDMA driver"); +MODULE_AUTHOR("Stefan Roese <sr@denx.de>"); +MODULE_LICENSE("GPL"); |