diff options
Diffstat (limited to 'drivers/dma/moxart-dma.c')
| -rw-r--r-- | drivers/dma/moxart-dma.c | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/drivers/dma/moxart-dma.c b/drivers/dma/moxart-dma.c new file mode 100644 index 000000000..b4634109e --- /dev/null +++ b/drivers/dma/moxart-dma.c @@ -0,0 +1,679 @@ +/* + * MOXA ART SoCs DMA Engine support. + * + * Copyright (C) 2013 Jonas Jensen + * + * Jonas Jensen <jonas.jensen@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_dma.h> +#include <linux/bitops.h> + +#include <asm/cacheflush.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +#define APB_DMA_MAX_CHANNEL 4 + +#define REG_OFF_ADDRESS_SOURCE 0 +#define REG_OFF_ADDRESS_DEST 4 +#define REG_OFF_CYCLES 8 +#define REG_OFF_CTRL 12 +#define REG_OFF_CHAN_SIZE 16 + +#define APB_DMA_ENABLE BIT(0) +#define APB_DMA_FIN_INT_STS BIT(1) +#define APB_DMA_FIN_INT_EN BIT(2) +#define APB_DMA_BURST_MODE BIT(3) +#define APB_DMA_ERR_INT_STS BIT(4) +#define APB_DMA_ERR_INT_EN BIT(5) + +/* + * Unset: APB + * Set: AHB + */ +#define APB_DMA_SOURCE_SELECT 0x40 +#define APB_DMA_DEST_SELECT 0x80 + +#define APB_DMA_SOURCE 0x100 +#define APB_DMA_DEST 0x1000 + +#define APB_DMA_SOURCE_MASK 0x700 +#define APB_DMA_DEST_MASK 0x7000 + +/* + * 000: No increment + * 001: +1 (Burst=0), +4 (Burst=1) + * 010: +2 (Burst=0), +8 (Burst=1) + * 011: +4 (Burst=0), +16 (Burst=1) + * 101: -1 (Burst=0), -4 (Burst=1) + * 110: -2 (Burst=0), -8 (Burst=1) + * 111: -4 (Burst=0), -16 (Burst=1) + */ +#define APB_DMA_SOURCE_INC_0 0 +#define APB_DMA_SOURCE_INC_1_4 0x100 +#define APB_DMA_SOURCE_INC_2_8 0x200 +#define APB_DMA_SOURCE_INC_4_16 0x300 +#define APB_DMA_SOURCE_DEC_1_4 0x500 +#define APB_DMA_SOURCE_DEC_2_8 0x600 +#define APB_DMA_SOURCE_DEC_4_16 0x700 +#define APB_DMA_DEST_INC_0 0 +#define APB_DMA_DEST_INC_1_4 0x1000 +#define APB_DMA_DEST_INC_2_8 0x2000 +#define APB_DMA_DEST_INC_4_16 0x3000 +#define APB_DMA_DEST_DEC_1_4 0x5000 +#define APB_DMA_DEST_DEC_2_8 0x6000 +#define APB_DMA_DEST_DEC_4_16 0x7000 + +/* + * Request signal select source/destination address for DMA hardware handshake. + * + * The request line number is a property of the DMA controller itself, + * e.g. MMC must always request channels where dma_slave_config->slave_id is 5. + * + * 0: No request / Grant signal + * 1-15: Request / Grant signal + */ +#define APB_DMA_SOURCE_REQ_NO 0x1000000 +#define APB_DMA_SOURCE_REQ_NO_MASK 0xf000000 +#define APB_DMA_DEST_REQ_NO 0x10000 +#define APB_DMA_DEST_REQ_NO_MASK 0xf0000 + +#define APB_DMA_DATA_WIDTH 0x100000 +#define APB_DMA_DATA_WIDTH_MASK 0x300000 +/* + * Data width of transfer: + * + * 00: Word + * 01: Half + * 10: Byte + */ +#define APB_DMA_DATA_WIDTH_4 0 +#define APB_DMA_DATA_WIDTH_2 0x100000 +#define APB_DMA_DATA_WIDTH_1 0x200000 + +#define APB_DMA_CYCLES_MASK 0x00ffffff + +#define MOXART_DMA_DATA_TYPE_S8 0x00 +#define MOXART_DMA_DATA_TYPE_S16 0x01 +#define MOXART_DMA_DATA_TYPE_S32 0x02 + +struct moxart_sg { + dma_addr_t addr; + uint32_t len; +}; + +struct moxart_desc { + enum dma_transfer_direction dma_dir; + dma_addr_t dev_addr; + unsigned int sglen; + unsigned int dma_cycles; + struct virt_dma_desc vd; + uint8_t es; + struct moxart_sg sg[0]; +}; + +struct moxart_chan { + struct virt_dma_chan vc; + + void __iomem *base; + struct moxart_desc *desc; + + struct dma_slave_config cfg; + + bool allocated; + bool error; + int ch_num; + unsigned int line_reqno; + unsigned int sgidx; +}; + +struct moxart_dmadev { + struct dma_device dma_slave; + struct moxart_chan slave_chans[APB_DMA_MAX_CHANNEL]; +}; + +struct moxart_filter_data { + struct moxart_dmadev *mdc; + struct of_phandle_args *dma_spec; +}; + +static const unsigned int es_bytes[] = { + [MOXART_DMA_DATA_TYPE_S8] = 1, + [MOXART_DMA_DATA_TYPE_S16] = 2, + [MOXART_DMA_DATA_TYPE_S32] = 4, +}; + +static struct device *chan2dev(struct dma_chan *chan) +{ + return &chan->dev->device; +} + +static inline struct moxart_chan *to_moxart_dma_chan(struct dma_chan *c) +{ + return container_of(c, struct moxart_chan, vc.chan); +} + +static inline struct moxart_desc *to_moxart_dma_desc( + struct dma_async_tx_descriptor *t) +{ + return container_of(t, struct moxart_desc, vd.tx); +} + +static void moxart_dma_desc_free(struct virt_dma_desc *vd) +{ + kfree(container_of(vd, struct moxart_desc, vd)); +} + +static int moxart_terminate_all(struct dma_chan *chan) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + unsigned long flags; + LIST_HEAD(head); + u32 ctrl; + + dev_dbg(chan2dev(chan), "%s: ch=%p\n", __func__, ch); + + spin_lock_irqsave(&ch->vc.lock, flags); + + if (ch->desc) { + moxart_dma_desc_free(&ch->desc->vd); + ch->desc = NULL; + } + + ctrl = readl(ch->base + REG_OFF_CTRL); + ctrl &= ~(APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN); + writel(ctrl, ch->base + REG_OFF_CTRL); + + vchan_get_all_descriptors(&ch->vc, &head); + spin_unlock_irqrestore(&ch->vc.lock, flags); + vchan_dma_desc_free_list(&ch->vc, &head); + + return 0; +} + +static int moxart_slave_config(struct dma_chan *chan, + struct dma_slave_config *cfg) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + u32 ctrl; + + ch->cfg = *cfg; + + ctrl = readl(ch->base + REG_OFF_CTRL); + ctrl |= APB_DMA_BURST_MODE; + ctrl &= ~(APB_DMA_DEST_MASK | APB_DMA_SOURCE_MASK); + ctrl &= ~(APB_DMA_DEST_REQ_NO_MASK | APB_DMA_SOURCE_REQ_NO_MASK); + + switch (ch->cfg.src_addr_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + ctrl |= APB_DMA_DATA_WIDTH_1; + if (ch->cfg.direction != DMA_MEM_TO_DEV) + ctrl |= APB_DMA_DEST_INC_1_4; + else + ctrl |= APB_DMA_SOURCE_INC_1_4; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + ctrl |= APB_DMA_DATA_WIDTH_2; + if (ch->cfg.direction != DMA_MEM_TO_DEV) + ctrl |= APB_DMA_DEST_INC_2_8; + else + ctrl |= APB_DMA_SOURCE_INC_2_8; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + ctrl &= ~APB_DMA_DATA_WIDTH; + if (ch->cfg.direction != DMA_MEM_TO_DEV) + ctrl |= APB_DMA_DEST_INC_4_16; + else + ctrl |= APB_DMA_SOURCE_INC_4_16; + break; + default: + return -EINVAL; + } + + if (ch->cfg.direction == DMA_MEM_TO_DEV) { + ctrl &= ~APB_DMA_DEST_SELECT; + ctrl |= APB_DMA_SOURCE_SELECT; + ctrl |= (ch->line_reqno << 16 & + APB_DMA_DEST_REQ_NO_MASK); + } else { + ctrl |= APB_DMA_DEST_SELECT; + ctrl &= ~APB_DMA_SOURCE_SELECT; + ctrl |= (ch->line_reqno << 24 & + APB_DMA_SOURCE_REQ_NO_MASK); + } + + writel(ctrl, ch->base + REG_OFF_CTRL); + + return 0; +} + +static struct dma_async_tx_descriptor *moxart_prep_slave_sg( + struct dma_chan *chan, struct scatterlist *sgl, + unsigned int sg_len, enum dma_transfer_direction dir, + unsigned long tx_flags, void *context) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + struct moxart_desc *d; + enum dma_slave_buswidth dev_width; + dma_addr_t dev_addr; + struct scatterlist *sgent; + unsigned int es; + unsigned int i; + + if (!is_slave_direction(dir)) { + dev_err(chan2dev(chan), "%s: invalid DMA direction\n", + __func__); + return NULL; + } + + if (dir == DMA_DEV_TO_MEM) { + dev_addr = ch->cfg.src_addr; + dev_width = ch->cfg.src_addr_width; + } else { + dev_addr = ch->cfg.dst_addr; + dev_width = ch->cfg.dst_addr_width; + } + + switch (dev_width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + es = MOXART_DMA_DATA_TYPE_S8; + break; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + es = MOXART_DMA_DATA_TYPE_S16; + break; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + es = MOXART_DMA_DATA_TYPE_S32; + break; + default: + dev_err(chan2dev(chan), "%s: unsupported data width (%u)\n", + __func__, dev_width); + return NULL; + } + + d = kzalloc(sizeof(*d) + sg_len * sizeof(d->sg[0]), GFP_ATOMIC); + if (!d) + return NULL; + + d->dma_dir = dir; + d->dev_addr = dev_addr; + d->es = es; + + for_each_sg(sgl, sgent, sg_len, i) { + d->sg[i].addr = sg_dma_address(sgent); + d->sg[i].len = sg_dma_len(sgent); + } + + d->sglen = sg_len; + + ch->error = 0; + + return vchan_tx_prep(&ch->vc, &d->vd, tx_flags); +} + +static struct dma_chan *moxart_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct moxart_dmadev *mdc = ofdma->of_dma_data; + struct dma_chan *chan; + struct moxart_chan *ch; + + chan = dma_get_any_slave_channel(&mdc->dma_slave); + if (!chan) + return NULL; + + ch = to_moxart_dma_chan(chan); + ch->line_reqno = dma_spec->args[0]; + + return chan; +} + +static int moxart_alloc_chan_resources(struct dma_chan *chan) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + + dev_dbg(chan2dev(chan), "%s: allocating channel #%u\n", + __func__, ch->ch_num); + ch->allocated = 1; + + return 0; +} + +static void moxart_free_chan_resources(struct dma_chan *chan) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + + vchan_free_chan_resources(&ch->vc); + + dev_dbg(chan2dev(chan), "%s: freeing channel #%u\n", + __func__, ch->ch_num); + ch->allocated = 0; +} + +static void moxart_dma_set_params(struct moxart_chan *ch, dma_addr_t src_addr, + dma_addr_t dst_addr) +{ + writel(src_addr, ch->base + REG_OFF_ADDRESS_SOURCE); + writel(dst_addr, ch->base + REG_OFF_ADDRESS_DEST); +} + +static void moxart_set_transfer_params(struct moxart_chan *ch, unsigned int len) +{ + struct moxart_desc *d = ch->desc; + unsigned int sglen_div = es_bytes[d->es]; + + d->dma_cycles = len >> sglen_div; + + /* + * There are 4 cycles on 64 bytes copied, i.e. one cycle copies 16 + * bytes ( when width is APB_DMAB_DATA_WIDTH_4 ). + */ + writel(d->dma_cycles, ch->base + REG_OFF_CYCLES); + + dev_dbg(chan2dev(&ch->vc.chan), "%s: set %u DMA cycles (len=%u)\n", + __func__, d->dma_cycles, len); +} + +static void moxart_start_dma(struct moxart_chan *ch) +{ + u32 ctrl; + + ctrl = readl(ch->base + REG_OFF_CTRL); + ctrl |= (APB_DMA_ENABLE | APB_DMA_FIN_INT_EN | APB_DMA_ERR_INT_EN); + writel(ctrl, ch->base + REG_OFF_CTRL); +} + +static void moxart_dma_start_sg(struct moxart_chan *ch, unsigned int idx) +{ + struct moxart_desc *d = ch->desc; + struct moxart_sg *sg = ch->desc->sg + idx; + + if (ch->desc->dma_dir == DMA_MEM_TO_DEV) + moxart_dma_set_params(ch, sg->addr, d->dev_addr); + else if (ch->desc->dma_dir == DMA_DEV_TO_MEM) + moxart_dma_set_params(ch, d->dev_addr, sg->addr); + + moxart_set_transfer_params(ch, sg->len); + + moxart_start_dma(ch); +} + +static void moxart_dma_start_desc(struct dma_chan *chan) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + struct virt_dma_desc *vd; + + vd = vchan_next_desc(&ch->vc); + + if (!vd) { + ch->desc = NULL; + return; + } + + list_del(&vd->node); + + ch->desc = to_moxart_dma_desc(&vd->tx); + ch->sgidx = 0; + + moxart_dma_start_sg(ch, 0); +} + +static void moxart_issue_pending(struct dma_chan *chan) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + unsigned long flags; + + spin_lock_irqsave(&ch->vc.lock, flags); + if (vchan_issue_pending(&ch->vc) && !ch->desc) + moxart_dma_start_desc(chan); + spin_unlock_irqrestore(&ch->vc.lock, flags); +} + +static size_t moxart_dma_desc_size(struct moxart_desc *d, + unsigned int completed_sgs) +{ + unsigned int i; + size_t size; + + for (size = i = completed_sgs; i < d->sglen; i++) + size += d->sg[i].len; + + return size; +} + +static size_t moxart_dma_desc_size_in_flight(struct moxart_chan *ch) +{ + size_t size; + unsigned int completed_cycles, cycles; + + size = moxart_dma_desc_size(ch->desc, ch->sgidx); + cycles = readl(ch->base + REG_OFF_CYCLES); + completed_cycles = (ch->desc->dma_cycles - cycles); + size -= completed_cycles << es_bytes[ch->desc->es]; + + dev_dbg(chan2dev(&ch->vc.chan), "%s: size=%zu\n", __func__, size); + + return size; +} + +static enum dma_status moxart_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct moxart_chan *ch = to_moxart_dma_chan(chan); + struct virt_dma_desc *vd; + struct moxart_desc *d; + enum dma_status ret; + unsigned long flags; + + /* + * dma_cookie_status() assigns initial residue value. + */ + ret = dma_cookie_status(chan, cookie, txstate); + + spin_lock_irqsave(&ch->vc.lock, flags); + vd = vchan_find_desc(&ch->vc, cookie); + if (vd) { + d = to_moxart_dma_desc(&vd->tx); + txstate->residue = moxart_dma_desc_size(d, 0); + } else if (ch->desc && ch->desc->vd.tx.cookie == cookie) { + txstate->residue = moxart_dma_desc_size_in_flight(ch); + } + spin_unlock_irqrestore(&ch->vc.lock, flags); + + if (ch->error) + return DMA_ERROR; + + return ret; +} + +static void moxart_dma_init(struct dma_device *dma, struct device *dev) +{ + dma->device_prep_slave_sg = moxart_prep_slave_sg; + dma->device_alloc_chan_resources = moxart_alloc_chan_resources; + dma->device_free_chan_resources = moxart_free_chan_resources; + dma->device_issue_pending = moxart_issue_pending; + dma->device_tx_status = moxart_tx_status; + dma->device_config = moxart_slave_config; + dma->device_terminate_all = moxart_terminate_all; + dma->dev = dev; + + INIT_LIST_HEAD(&dma->channels); +} + +static irqreturn_t moxart_dma_interrupt(int irq, void *devid) +{ + struct moxart_dmadev *mc = devid; + struct moxart_chan *ch = &mc->slave_chans[0]; + unsigned int i; + unsigned long flags; + u32 ctrl; + + dev_dbg(chan2dev(&ch->vc.chan), "%s\n", __func__); + + for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) { + if (!ch->allocated) + continue; + + ctrl = readl(ch->base + REG_OFF_CTRL); + + dev_dbg(chan2dev(&ch->vc.chan), "%s: ch=%p ch->base=%p ctrl=%x\n", + __func__, ch, ch->base, ctrl); + + if (ctrl & APB_DMA_FIN_INT_STS) { + ctrl &= ~APB_DMA_FIN_INT_STS; + if (ch->desc) { + spin_lock_irqsave(&ch->vc.lock, flags); + if (++ch->sgidx < ch->desc->sglen) { + moxart_dma_start_sg(ch, ch->sgidx); + } else { + vchan_cookie_complete(&ch->desc->vd); + moxart_dma_start_desc(&ch->vc.chan); + } + spin_unlock_irqrestore(&ch->vc.lock, flags); + } + } + + if (ctrl & APB_DMA_ERR_INT_STS) { + ctrl &= ~APB_DMA_ERR_INT_STS; + ch->error = 1; + } + + writel(ctrl, ch->base + REG_OFF_CTRL); + } + + return IRQ_HANDLED; +} + +static int moxart_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + struct resource *res; + static void __iomem *dma_base_addr; + int ret, i; + unsigned int irq; + struct moxart_chan *ch; + struct moxart_dmadev *mdc; + + mdc = devm_kzalloc(dev, sizeof(*mdc), GFP_KERNEL); + if (!mdc) { + dev_err(dev, "can't allocate DMA container\n"); + return -ENOMEM; + } + + irq = irq_of_parse_and_map(node, 0); + if (irq == NO_IRQ) { + dev_err(dev, "no IRQ resource\n"); + return -EINVAL; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dma_base_addr = devm_ioremap_resource(dev, res); + if (IS_ERR(dma_base_addr)) + return PTR_ERR(dma_base_addr); + + dma_cap_zero(mdc->dma_slave.cap_mask); + dma_cap_set(DMA_SLAVE, mdc->dma_slave.cap_mask); + dma_cap_set(DMA_PRIVATE, mdc->dma_slave.cap_mask); + + moxart_dma_init(&mdc->dma_slave, dev); + + ch = &mdc->slave_chans[0]; + for (i = 0; i < APB_DMA_MAX_CHANNEL; i++, ch++) { + ch->ch_num = i; + ch->base = dma_base_addr + i * REG_OFF_CHAN_SIZE; + ch->allocated = 0; + + ch->vc.desc_free = moxart_dma_desc_free; + vchan_init(&ch->vc, &mdc->dma_slave); + + dev_dbg(dev, "%s: chs[%d]: ch->ch_num=%u ch->base=%p\n", + __func__, i, ch->ch_num, ch->base); + } + + platform_set_drvdata(pdev, mdc); + + ret = devm_request_irq(dev, irq, moxart_dma_interrupt, 0, + "moxart-dma-engine", mdc); + if (ret) { + dev_err(dev, "devm_request_irq failed\n"); + return ret; + } + + ret = dma_async_device_register(&mdc->dma_slave); + if (ret) { + dev_err(dev, "dma_async_device_register failed\n"); + return ret; + } + + ret = of_dma_controller_register(node, moxart_of_xlate, mdc); + if (ret) { + dev_err(dev, "of_dma_controller_register failed\n"); + dma_async_device_unregister(&mdc->dma_slave); + return ret; + } + + dev_dbg(dev, "%s: IRQ=%u\n", __func__, irq); + + return 0; +} + +static int moxart_remove(struct platform_device *pdev) +{ + struct moxart_dmadev *m = platform_get_drvdata(pdev); + + dma_async_device_unregister(&m->dma_slave); + + if (pdev->dev.of_node) + of_dma_controller_free(pdev->dev.of_node); + + return 0; +} + +static const struct of_device_id moxart_dma_match[] = { + { .compatible = "moxa,moxart-dma" }, + { } +}; + +static struct platform_driver moxart_driver = { + .probe = moxart_probe, + .remove = moxart_remove, + .driver = { + .name = "moxart-dma-engine", + .of_match_table = moxart_dma_match, + }, +}; + +static int moxart_init(void) +{ + return platform_driver_register(&moxart_driver); +} +subsys_initcall(moxart_init); + +static void __exit moxart_exit(void) +{ + platform_driver_unregister(&moxart_driver); +} +module_exit(moxart_exit); + +MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>"); +MODULE_DESCRIPTION("MOXART DMA engine driver"); +MODULE_LICENSE("GPL v2"); |