Hi Dmitry, On 26/09/17 00:22, Dmitry Osipenko wrote: > AHB DMA controller presents on Tegra20/30 SoC's, it supports transfers > memory <-> AHB bus peripherals as well as mem-to-mem transfers. Driver > doesn't yet implement transfers larger than 64K and scatter-gather > transfers that have NENT > 1, HW doesn't have native support for these > cases. > > Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> > --- > drivers/dma/Kconfig | 9 + > drivers/dma/Makefile | 1 + > drivers/dma/tegra20-ahb-dma.c | 679 ++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 689 insertions(+) > create mode 100644 drivers/dma/tegra20-ahb-dma.c ... > diff --git a/drivers/dma/tegra20-ahb-dma.c b/drivers/dma/tegra20-ahb-dma.c > new file mode 100644 > index 000000000000..8316d64e35e1 > --- /dev/null > +++ b/drivers/dma/tegra20-ahb-dma.c > @@ -0,0 +1,679 @@ > +/* > + * Copyright 2017 Dmitry Osipenko <digetx@xxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/interrupt.h> > +#include <linux/io.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/of_dma.h> > +#include <linux/platform_device.h> > +#include <linux/reset.h> > +#include <linux/slab.h> > +#include <linux/spinlock.h> > + > +#include "dmaengine.h" > + > +#define TEGRA_AHBDMA_CMD 0x0 > +#define TEGRA_AHBDMA_CMD_ENABLE BIT(31) > + > +#define TEGRA_AHBDMA_IRQ_ENB_MASK 0x20 > +#define TEGRA_AHBDMA_IRQ_ENB_CH(ch) BIT(ch) > + > +#define TEGRA_AHBDMA_CHANNEL_BASE(ch) (0x1000 + (ch) * 0x20) > + > +#define TEGRA_AHBDMA_CHANNEL_CSR 0x0 > +#define TEGRA_AHBDMA_CHANNEL_ADDR_WRAP BIT(18) > +#define TEGRA_AHBDMA_CHANNEL_FLOW BIT(24) > +#define TEGRA_AHBDMA_CHANNEL_ONCE BIT(26) > +#define TEGRA_AHBDMA_CHANNEL_DIR_TO_XMB BIT(27) > +#define TEGRA_AHBDMA_CHANNEL_IE_EOC BIT(30) > +#define TEGRA_AHBDMA_CHANNEL_ENABLE BIT(31) > +#define TEGRA_AHBDMA_CHANNEL_REQ_SEL_SHIFT 16 > +#define TEGRA_AHBDMA_CHANNEL_WCOUNT_MASK 0xFFFC > + > +#define TEGRA_AHBDMA_CHANNEL_STA 0x4 > +#define TEGRA_AHBDMA_CHANNEL_IS_EOC BIT(30) > + > +#define TEGRA_AHBDMA_CHANNEL_AHB_PTR 0x10 > + > +#define TEGRA_AHBDMA_CHANNEL_AHB_SEQ 0x14 > +#define TEGRA_AHBDMA_CHANNEL_INTR_ENB BIT(31) > +#define TEGRA_AHBDMA_CHANNEL_AHB_BURST_SHIFT 24 > +#define TEGRA_AHBDMA_CHANNEL_AHB_BURST_1 2 > +#define TEGRA_AHBDMA_CHANNEL_AHB_BURST_4 3 > +#define TEGRA_AHBDMA_CHANNEL_AHB_BURST_8 4 > + > +#define TEGRA_AHBDMA_CHANNEL_XMB_PTR 0x18 > + > +#define TEGRA_AHBDMA_BUS_WIDTH BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) > + > +#define TEGRA_AHBDMA_DIRECTIONS BIT(DMA_DEV_TO_MEM) | \ > + BIT(DMA_MEM_TO_DEV) > + > +struct tegra_ahbdma_tx_desc { > + struct dma_async_tx_descriptor desc; > + struct tasklet_struct tasklet; > + struct list_head node; Any reason why we cannot use the virt-dma framework for this driver? I would hope it would simplify the driver a bit. > + enum dma_transfer_direction dir; > + dma_addr_t mem_paddr; > + unsigned long flags; > + size_t size; > + bool in_fly; > + bool cyclic; > +}; > + > +struct tegra_ahbdma_chan { > + struct dma_chan dma_chan; > + struct list_head active_list; > + struct list_head pending_list; > + struct completion idling; > + void __iomem *regs; > + spinlock_t lock; > + unsigned int id; > +}; > + > +struct tegra_ahbdma { > + struct tegra_ahbdma_chan channels[4]; > + struct dma_device dma_dev; > + struct reset_control *rst; > + struct clk *clk; > + void __iomem *regs; > +}; > + > +static inline struct tegra_ahbdma *to_ahbdma(struct dma_device *dev) > +{ > + return container_of(dev, struct tegra_ahbdma, dma_dev); > +} > + > +static inline struct tegra_ahbdma_chan *to_ahbdma_chan(struct dma_chan *chan) > +{ > + return container_of(chan, struct tegra_ahbdma_chan, dma_chan); > +} > + > +static inline struct tegra_ahbdma_tx_desc *to_ahbdma_tx_desc( > + struct dma_async_tx_descriptor *tx) > +{ > + return container_of(tx, struct tegra_ahbdma_tx_desc, desc); > +} > + > +static void tegra_ahbdma_submit_tx(struct tegra_ahbdma_chan *chan, > + struct tegra_ahbdma_tx_desc *tx) > +{ > + u32 csr; > + > + writel_relaxed(tx->mem_paddr, > + chan->regs + TEGRA_AHBDMA_CHANNEL_XMB_PTR); > + > + csr = readl_relaxed(chan->regs + TEGRA_AHBDMA_CHANNEL_CSR); > + > + csr &= ~TEGRA_AHBDMA_CHANNEL_WCOUNT_MASK; > + csr &= ~TEGRA_AHBDMA_CHANNEL_DIR_TO_XMB; > + csr |= TEGRA_AHBDMA_CHANNEL_ENABLE; > + csr |= TEGRA_AHBDMA_CHANNEL_IE_EOC; > + csr |= tx->size - sizeof(u32); > + > + if (tx->dir == DMA_DEV_TO_MEM) > + csr |= TEGRA_AHBDMA_CHANNEL_DIR_TO_XMB; > + > + if (!tx->cyclic) > + csr |= TEGRA_AHBDMA_CHANNEL_ONCE; > + > + writel_relaxed(csr, chan->regs + TEGRA_AHBDMA_CHANNEL_CSR); > + > + tx->in_fly = true; > +} > + > +static void tegra_ahbdma_tasklet(unsigned long data) > +{ > + struct tegra_ahbdma_tx_desc *tx = (struct tegra_ahbdma_tx_desc *)data; > + struct dma_async_tx_descriptor *desc = &tx->desc; > + > + dmaengine_desc_get_callback_invoke(desc, NULL); > + > + if (!tx->cyclic && !dmaengine_desc_test_reuse(desc)) > + kfree(tx); > +} > + > +static bool tegra_ahbdma_tx_completed(struct tegra_ahbdma_chan *chan, > + struct tegra_ahbdma_tx_desc *tx) > +{ > + struct dma_async_tx_descriptor *desc = &tx->desc; > + bool reuse = dmaengine_desc_test_reuse(desc); > + bool interrupt = tx->flags & DMA_PREP_INTERRUPT; > + bool completed = !tx->cyclic; > + > + if (completed) > + dma_cookie_complete(desc); > + > + if (interrupt) > + tasklet_schedule(&tx->tasklet); > + > + if (completed) { > + list_del(&tx->node); > + > + if (reuse) > + tx->in_fly = false; > + > + if (!interrupt && !reuse) > + kfree(tx); > + } > + > + return completed; > +} > + > +static bool tegra_ahbdma_next_tx_issued(struct tegra_ahbdma_chan *chan) > +{ > + struct tegra_ahbdma_tx_desc *tx; > + > + tx = list_first_entry_or_null(&chan->active_list, > + struct tegra_ahbdma_tx_desc, > + node); > + if (tx) > + tegra_ahbdma_submit_tx(chan, tx); > + > + return !!tx; > +} > + > +static void tegra_ahbdma_handle_channel(struct tegra_ahbdma_chan *chan) > +{ > + struct tegra_ahbdma_tx_desc *tx; > + unsigned long flags; > + u32 status; > + > + status = readl_relaxed(chan->regs + TEGRA_AHBDMA_CHANNEL_STA); > + if (!(status & TEGRA_AHBDMA_CHANNEL_IS_EOC)) > + return; > + > + writel_relaxed(TEGRA_AHBDMA_CHANNEL_IS_EOC, > + chan->regs + TEGRA_AHBDMA_CHANNEL_STA); > + > + spin_lock_irqsave(&chan->lock, flags); > + > + if (!completion_done(&chan->idling)) { > + tx = list_first_entry(&chan->active_list, > + struct tegra_ahbdma_tx_desc, > + node); > + > + if (tegra_ahbdma_tx_completed(chan, tx) && > + !tegra_ahbdma_next_tx_issued(chan)) > + complete_all(&chan->idling); > + } > + > + spin_unlock_irqrestore(&chan->lock, flags); > +} > + > +static irqreturn_t tegra_ahbdma_isr(int irq, void *dev_id) > +{ > + struct tegra_ahbdma *tdma = dev_id; > + unsigned int i; > + > + for (i = 0; i < ARRAY_SIZE(tdma->channels); i++) > + tegra_ahbdma_handle_channel(&tdma->channels[i]); > + > + return IRQ_HANDLED; > +} > + > +static dma_cookie_t tegra_ahbdma_tx_submit(struct dma_async_tx_descriptor *desc) > +{ > + struct tegra_ahbdma_tx_desc *tx = to_ahbdma_tx_desc(desc); > + struct tegra_ahbdma_chan *chan = to_ahbdma_chan(desc->chan); > + dma_cookie_t cookie; > + > + cookie = dma_cookie_assign(desc); > + > + spin_lock_irq(&chan->lock); > + list_add_tail(&tx->node, &chan->pending_list); > + spin_unlock_irq(&chan->lock); > + > + return cookie; > +} > + > +static int tegra_ahbdma_tx_desc_free(struct dma_async_tx_descriptor *desc) > +{ > + kfree(to_ahbdma_tx_desc(desc)); > + > + return 0; > +} > + > +static struct dma_async_tx_descriptor *tegra_ahbdma_prep_slave_sg( > + struct dma_chan *chan, > + struct scatterlist *sgl, > + unsigned int sg_len, > + enum dma_transfer_direction dir, > + unsigned long flags, > + void *context) > +{ > + struct tegra_ahbdma_tx_desc *tx; > + > + /* unimplemented */ > + if (sg_len != 1 || sg_dma_len(sgl) > SZ_64K) > + return NULL; > + > + tx = kzalloc(sizeof(*tx), GFP_KERNEL); > + if (!tx) > + return NULL; > + > + dma_async_tx_descriptor_init(&tx->desc, chan); > + > + tx->desc.tx_submit = tegra_ahbdma_tx_submit; > + tx->desc.desc_free = tegra_ahbdma_tx_desc_free; > + tx->mem_paddr = sg_dma_address(sgl); > + tx->size = sg_dma_len(sgl); > + tx->flags = flags; > + tx->dir = dir; > + > + tasklet_init(&tx->tasklet, tegra_ahbdma_tasklet, (unsigned long)tx); > + > + return &tx->desc; > +} > + > +static struct dma_async_tx_descriptor *tegra_ahbdma_prep_dma_cyclic( > + struct dma_chan *chan, > + dma_addr_t buf_addr, > + size_t buf_len, > + size_t period_len, > + enum dma_transfer_direction dir, > + unsigned long flags) > +{ > + struct tegra_ahbdma_tx_desc *tx; > + > + /* unimplemented */ > + if (buf_len != period_len || buf_len > SZ_64K) > + return NULL; > + > + tx = kzalloc(sizeof(*tx), GFP_KERNEL); > + if (!tx) > + return NULL; > + > + dma_async_tx_descriptor_init(&tx->desc, chan); > + > + tx->desc.tx_submit = tegra_ahbdma_tx_submit; > + tx->mem_paddr = buf_addr; > + tx->size = buf_len; > + tx->flags = flags; > + tx->cyclic = true; > + tx->dir = dir; > + > + tasklet_init(&tx->tasklet, tegra_ahbdma_tasklet, (unsigned long)tx); > + > + return &tx->desc; > +} > + > +static void tegra_ahbdma_issue_pending(struct dma_chan *chan) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = to_ahbdma_chan(chan); > + struct tegra_ahbdma_tx_desc *tx; > + struct list_head *entry, *tmp; > + unsigned long flags; > + > + spin_lock_irqsave(&ahbdma_chan->lock, flags); > + > + list_for_each_safe(entry, tmp, &ahbdma_chan->pending_list) > + list_move_tail(entry, &ahbdma_chan->active_list); > + > + if (completion_done(&ahbdma_chan->idling)) { > + tx = list_first_entry_or_null(&ahbdma_chan->active_list, > + struct tegra_ahbdma_tx_desc, > + node); > + if (tx) { > + tegra_ahbdma_submit_tx(ahbdma_chan, tx); > + reinit_completion(&ahbdma_chan->idling); > + } > + } > + > + spin_unlock_irqrestore(&ahbdma_chan->lock, flags); > +} > + > +static enum dma_status tegra_ahbdma_tx_status(struct dma_chan *chan, > + dma_cookie_t cookie, > + struct dma_tx_state *state) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = to_ahbdma_chan(chan); > + struct tegra_ahbdma_tx_desc *tx; > + enum dma_status cookie_status; > + unsigned long flags; > + size_t residual; > + u32 status; > + > + spin_lock_irqsave(&ahbdma_chan->lock, flags); > + > + cookie_status = dma_cookie_status(chan, cookie, state); > + if (cookie_status != DMA_COMPLETE) { > + list_for_each_entry(tx, &ahbdma_chan->active_list, node) { > + if (tx->desc.cookie == cookie) > + goto found; > + } > + } > + > + goto unlock; > + > +found: > + if (tx->in_fly) { > + status = readl_relaxed( > + ahbdma_chan->regs + TEGRA_AHBDMA_CHANNEL_STA); > + status &= TEGRA_AHBDMA_CHANNEL_WCOUNT_MASK; > + > + residual = status; > + } else > + residual = tx->size; > + > + dma_set_residue(state, residual); > + > +unlock: > + spin_unlock_irqrestore(&ahbdma_chan->lock, flags); > + > + return cookie_status; > +} > + > +static int tegra_ahbdma_terminate_all(struct dma_chan *chan) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = to_ahbdma_chan(chan); > + struct tegra_ahbdma_tx_desc *tx; > + struct list_head *entry, *tmp; > + u32 csr; > + > + spin_lock_irq(&ahbdma_chan->lock); > + > + csr = readl_relaxed(ahbdma_chan->regs + TEGRA_AHBDMA_CHANNEL_CSR); > + csr &= ~TEGRA_AHBDMA_CHANNEL_ENABLE; > + > + writel_relaxed(csr, ahbdma_chan->regs + TEGRA_AHBDMA_CHANNEL_CSR); > + > + list_for_each_safe(entry, tmp, &ahbdma_chan->active_list) { > + tx = list_entry(entry, struct tegra_ahbdma_tx_desc, node); > + list_del(entry); > + kfree(tx); > + } > + > + list_for_each_safe(entry, tmp, &ahbdma_chan->pending_list) { > + tx = list_entry(entry, struct tegra_ahbdma_tx_desc, node); > + list_del(entry); > + kfree(tx); > + } > + > + complete_all(&ahbdma_chan->idling); > + > + spin_unlock_irq(&ahbdma_chan->lock); > + > + return 0; > +} > + > +static int tegra_ahbdma_config(struct dma_chan *chan, > + struct dma_slave_config *sconfig) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = to_ahbdma_chan(chan); > + enum dma_transfer_direction dir = sconfig->direction; > + u32 burst, ahb_seq, ahb_addr; > + > + if (sconfig->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES || > + sconfig->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) > + return -EINVAL; > + > + if (dir == DMA_DEV_TO_MEM) { > + burst = sconfig->src_maxburst; > + ahb_addr = sconfig->src_addr; > + } else { > + burst = sconfig->dst_maxburst; > + ahb_addr = sconfig->dst_addr; > + } > + > + switch (burst) { > + case 1: burst = TEGRA_AHBDMA_CHANNEL_AHB_BURST_1; break; > + case 4: burst = TEGRA_AHBDMA_CHANNEL_AHB_BURST_4; break; > + case 8: burst = TEGRA_AHBDMA_CHANNEL_AHB_BURST_8; break; > + default: > + return -EINVAL; > + } > + > + ahb_seq = burst << TEGRA_AHBDMA_CHANNEL_AHB_BURST_SHIFT; > + ahb_seq |= TEGRA_AHBDMA_CHANNEL_ADDR_WRAP; > + ahb_seq |= TEGRA_AHBDMA_CHANNEL_INTR_ENB; > + > + writel_relaxed(ahb_seq, > + ahbdma_chan->regs + TEGRA_AHBDMA_CHANNEL_AHB_SEQ); > + > + writel_relaxed(ahb_addr, > + ahbdma_chan->regs + TEGRA_AHBDMA_CHANNEL_AHB_PTR); > + > + return 0; > +} > + > +static void tegra_ahbdma_synchronize(struct dma_chan *chan) > +{ > + wait_for_completion(&to_ahbdma_chan(chan)->idling); > +} > + > +static void tegra_ahbdma_free_chan_resources(struct dma_chan *chan) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = to_ahbdma_chan(chan); > + struct tegra_ahbdma_tx_desc *tx; > + struct list_head *entry, *tmp; > + > + list_for_each_safe(entry, tmp, &ahbdma_chan->pending_list) { > + tx = list_entry(entry, struct tegra_ahbdma_tx_desc, node); > + list_del(entry); > + kfree(tx); > + } > +} > + > +static void tegra_ahbdma_init_channel(struct tegra_ahbdma *tdma, > + unsigned int chan_id) > +{ > + struct tegra_ahbdma_chan *ahbdma_chan = &tdma->channels[chan_id]; > + struct dma_chan *dma_chan = &ahbdma_chan->dma_chan; > + struct dma_device *dma_dev = &tdma->dma_dev; > + > + INIT_LIST_HEAD(&ahbdma_chan->active_list); > + INIT_LIST_HEAD(&ahbdma_chan->pending_list); > + init_completion(&ahbdma_chan->idling); > + spin_lock_init(&ahbdma_chan->lock); > + complete(&ahbdma_chan->idling); > + > + ahbdma_chan->regs = tdma->regs + TEGRA_AHBDMA_CHANNEL_BASE(chan_id); > + ahbdma_chan->id = chan_id; > + > + dma_cookie_init(dma_chan); > + dma_chan->device = dma_dev; > + > + list_add_tail(&dma_chan->device_node, &dma_dev->channels); > +} > + > +static struct dma_chan *tegra_ahbdma_of_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma) > +{ > + struct tegra_ahbdma *tdma = ofdma->of_dma_data; > + struct dma_chan *chan; > + u32 csr; > + > + chan = dma_get_any_slave_channel(&tdma->dma_dev); > + if (!chan) > + return NULL; > + > + /* enable channels flow control */ > + if (dma_spec->args_count == 1) { The DT doc says #dma-cells should be '1' and so if not equal 1, is this not an error? > + csr = TEGRA_AHBDMA_CHANNEL_FLOW; > + csr |= dma_spec->args[0] << TEGRA_AHBDMA_CHANNEL_REQ_SEL_SHIFT; What about the TRIG_REQ field? > + > + writel_relaxed(csr, > + to_ahbdma_chan(chan)->regs + TEGRA_AHBDMA_CHANNEL_CSR); > + } > + > + return chan; > +} > + > +static int tegra_ahbdma_init_hw(struct tegra_ahbdma *tdma, struct device *dev) > +{ > + int err; > + > + err = reset_control_assert(tdma->rst); > + if (err) { > + dev_err(dev, "Failed to assert reset: %d\n", err); > + return err; > + } > + > + err = clk_prepare_enable(tdma->clk); > + if (err) { > + dev_err(dev, "Failed to enable clock: %d\n", err); > + return err; > + } > + > + usleep_range(1000, 2000); > + > + err = reset_control_deassert(tdma->rst); > + if (err) { > + dev_err(dev, "Failed to deassert reset: %d\n", err); > + return err; > + } > + > + writel_relaxed(TEGRA_AHBDMA_CMD_ENABLE, tdma->regs + TEGRA_AHBDMA_CMD); > + > + writel_relaxed(TEGRA_AHBDMA_IRQ_ENB_CH(0) | > + TEGRA_AHBDMA_IRQ_ENB_CH(1) | > + TEGRA_AHBDMA_IRQ_ENB_CH(2) | > + TEGRA_AHBDMA_IRQ_ENB_CH(3), > + tdma->regs + TEGRA_AHBDMA_IRQ_ENB_MASK); > + > + return 0; > +} Personally I would use the pm_runtime callbacks for this sort of thing and ... > +static int tegra_ahbdma_probe(struct platform_device *pdev) > +{ > + struct dma_device *dma_dev; > + struct tegra_ahbdma *tdma; > + struct resource *res_regs; > + unsigned int i; > + int irq; > + int err; > + > + tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma), GFP_KERNEL); > + if (!tdma) > + return -ENOMEM; > + > + irq = platform_get_irq(pdev, 0); > + if (irq < 0) { > + dev_err(&pdev->dev, "Failed to get IRQ\n"); > + return irq; > + } > + > + err = devm_request_irq(&pdev->dev, irq, tegra_ahbdma_isr, 0, > + dev_name(&pdev->dev), tdma); > + if (err) { > + dev_err(&pdev->dev, "Failed to request IRQ\n"); > + return -ENODEV; > + } > + > + res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res_regs) > + return -ENODEV; > + > + tdma->regs = devm_ioremap_resource(&pdev->dev, res_regs); > + if (IS_ERR(tdma->regs)) > + return PTR_ERR(tdma->regs); > + > + tdma->clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(tdma->clk)) { > + dev_err(&pdev->dev, "Failed to get AHB-DMA clock\n"); > + return PTR_ERR(tdma->clk); > + } > + > + tdma->rst = devm_reset_control_get(&pdev->dev, NULL); > + if (IS_ERR(tdma->rst)) { > + dev_err(&pdev->dev, "Failed to get AHB-DMA reset\n"); > + return PTR_ERR(tdma->rst); > + } > + > + err = tegra_ahbdma_init_hw(tdma, &pdev->dev); > + if (err) > + return err; ... here is looks like we turn the clocks on and leave them on. I would rather that we turn them on when the DMA channel is requested and turn them off again when freed. Again would be good to use pm_runtime APIs for this. > + dma_dev = &tdma->dma_dev; > + > + INIT_LIST_HEAD(&dma_dev->channels); > + > + for (i = 0; i < ARRAY_SIZE(tdma->channels); i++) > + tegra_ahbdma_init_channel(tdma, i); > + > + dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask); > + dma_cap_set(DMA_CYCLIC, dma_dev->cap_mask); > + dma_cap_set(DMA_SLAVE, dma_dev->cap_mask); > + > + dma_dev->max_burst = 8; > + dma_dev->directions = TEGRA_AHBDMA_DIRECTIONS; > + dma_dev->src_addr_widths = TEGRA_AHBDMA_BUS_WIDTH; > + dma_dev->dst_addr_widths = TEGRA_AHBDMA_BUS_WIDTH; > + dma_dev->descriptor_reuse = true; > + dma_dev->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; > + dma_dev->device_free_chan_resources = tegra_ahbdma_free_chan_resources; > + dma_dev->device_prep_slave_sg = tegra_ahbdma_prep_slave_sg; > + dma_dev->device_prep_dma_cyclic = tegra_ahbdma_prep_dma_cyclic; > + dma_dev->device_terminate_all = tegra_ahbdma_terminate_all; > + dma_dev->device_issue_pending = tegra_ahbdma_issue_pending; > + dma_dev->device_tx_status = tegra_ahbdma_tx_status; > + dma_dev->device_config = tegra_ahbdma_config; > + dma_dev->device_synchronize = tegra_ahbdma_synchronize; > + dma_dev->dev = &pdev->dev; > + > + err = dma_async_device_register(dma_dev); > + if (err) { > + dev_err(&pdev->dev, "Device registration failed %d\n", err); > + return err; > + } > + > + err = of_dma_controller_register(pdev->dev.of_node, > + tegra_ahbdma_of_xlate, tdma); > + if (err) { > + dev_err(&pdev->dev, "OF registration failed %d\n", err); > + dma_async_device_unregister(dma_dev); > + return err; > + } > + > + platform_set_drvdata(pdev, tdma); > + > + return 0; > +} > + > +static int tegra_ahbdma_remove(struct platform_device *pdev) > +{ > + struct tegra_ahbdma *tdma = platform_get_drvdata(pdev); > + > + of_dma_controller_free(pdev->dev.of_node); > + dma_async_device_unregister(&tdma->dma_dev); > + clk_disable_unprepare(tdma->clk); > + > + return 0; > +} > + > +static const struct of_device_id tegra_ahbdma_of_match[] = { > + { .compatible = "nvidia,tegra20-ahbdma" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, tegra_ahbdma_of_match); > + > +static struct platform_driver tegra_ahbdma_driver = { > + .driver = { > + .name = "tegra-ahbdma", > + .of_match_table = tegra_ahbdma_of_match, It would be nice to have suspend/resume handler too. We could do a similar thing to the APB dma driver. > + }, > + .probe = tegra_ahbdma_probe, > + .remove = tegra_ahbdma_remove, > +}; > +module_platform_driver(tegra_ahbdma_driver); > + > +MODULE_DESCRIPTION("NVIDIA Tegra AHB DMA Controller driver"); > +MODULE_AUTHOR("Dmitry Osipenko <digetx@xxxxxxxxx>"); > +MODULE_LICENSE("GPL"); Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
