From bbe89c8e3d598129b728d1388c3ad9abe4e8e261 Mon Sep 17 00:00:00 2001 From: Ludovic Desroches Date: Fri, 19 Apr 2013 09:11:18 +0000 Subject: [PATCH] at_hdmac: move to generic DMA binding Update at_hdmac driver to support generic DMA device tree binding. Devices can still request channel with dma_request_channel() then it doesn't break DMA for non DT boards. Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre Acked-by: Jean-Christophe PLAGNIOL-VILLARD Acked-by: Arnd Bergmann Signed-off-by: Vinod Koul --- .../devicetree/bindings/dma/atmel-dma.txt | 35 ++++++- drivers/dma/at_hdmac.c | 93 +++++++++++++++++-- drivers/dma/at_hdmac_regs.h | 4 + 3 files changed, 121 insertions(+), 11 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt index 3c046ee6e8b5..c80e8a3402f0 100644 --- a/Documentation/devicetree/bindings/dma/atmel-dma.txt +++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt @@ -1,14 +1,39 @@ * Atmel Direct Memory Access Controller (DMA) Required properties: -- compatible: Should be "atmel,-dma" -- reg: Should contain DMA registers location and length -- interrupts: Should contain DMA interrupt +- compatible: Should be "atmel,-dma". +- reg: Should contain DMA registers location and length. +- interrupts: Should contain DMA interrupt. +- #dma-cells: Must be <2>, used to represent the number of integer cells in +the dmas property of client devices. -Examples: +Example: -dma@ffffec00 { +dma0: dma@ffffec00 { compatible = "atmel,at91sam9g45-dma"; reg = <0xffffec00 0x200>; interrupts = <21>; + #dma-cells = <2>; +}; + +DMA clients connected to the Atmel DMA controller must use the format +described in the dma.txt file, using a three-cell specifier for each channel: +a phandle plus two interger cells. +The three cells in order are: + +1. A phandle pointing to the DMA controller. +2. The memory interface (16 most significant bits), the peripheral interface +(16 less significant bits). +3. The peripheral identifier for the hardware handshaking interface. The +identifier can be different for tx and rx. + +Example: + +i2c0@i2c@f8010000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8010000 0x100>; + interrupts = <9 4 6>; + dmas = <&dma0 1 7>, + <&dma0 1 8>; + dma-names = "tx", "rx"; }; diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index 841546776159..3502c412caf9 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -24,6 +24,7 @@ #include #include #include +#include #include "at_hdmac_regs.h" #include "dmaengine.h" @@ -676,7 +677,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, ctrlb |= ATC_DST_ADDR_MODE_FIXED | ATC_SRC_ADDR_MODE_INCR | ATC_FC_MEM2PER - | ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF); + | ATC_SIF(atchan->mem_if) | ATC_DIF(atchan->per_if); reg = sconfig->dst_addr; for_each_sg(sgl, sg, sg_len, i) { struct at_desc *desc; @@ -715,7 +716,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, ctrlb |= ATC_DST_ADDR_MODE_INCR | ATC_SRC_ADDR_MODE_FIXED | ATC_FC_PER2MEM - | ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF); + | ATC_SIF(atchan->per_if) | ATC_DIF(atchan->mem_if); reg = sconfig->src_addr; for_each_sg(sgl, sg, sg_len, i) { @@ -821,8 +822,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED | ATC_SRC_ADDR_MODE_INCR | ATC_FC_MEM2PER - | ATC_SIF(AT_DMA_MEM_IF) - | ATC_DIF(AT_DMA_PER_IF); + | ATC_SIF(atchan->mem_if) + | ATC_DIF(atchan->per_if); break; case DMA_DEV_TO_MEM: @@ -832,8 +833,8 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR | ATC_SRC_ADDR_MODE_FIXED | ATC_FC_PER2MEM - | ATC_SIF(AT_DMA_PER_IF) - | ATC_DIF(AT_DMA_MEM_IF); + | ATC_SIF(atchan->per_if) + | ATC_DIF(atchan->mem_if); break; default: @@ -1189,6 +1190,67 @@ static void atc_free_chan_resources(struct dma_chan *chan) dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); } +#ifdef CONFIG_OF +static bool at_dma_filter(struct dma_chan *chan, void *slave) +{ + struct at_dma_slave *atslave = slave; + + if (atslave->dma_dev == chan->device->dev) { + chan->private = atslave; + return true; + } else { + return false; + } +} + +static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *of_dma) +{ + struct dma_chan *chan; + struct at_dma_chan *atchan; + struct at_dma_slave *atslave; + dma_cap_mask_t mask; + unsigned int per_id; + struct platform_device *dmac_pdev; + + if (dma_spec->args_count != 2) + return NULL; + + dmac_pdev = of_find_device_by_node(dma_spec->np); + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL); + if (!atslave) + return NULL; + /* + * We can fill both SRC_PER and DST_PER, one of these fields will be + * ignored depending on DMA transfer direction. + */ + per_id = dma_spec->args[1]; + atslave->cfg = ATC_FIFOCFG_HALFFIFO | ATC_DST_H2SEL_HW + | ATC_SRC_H2SEL_HW | ATC_DST_PER(per_id) + | ATC_SRC_PER(per_id); + atslave->dma_dev = &dmac_pdev->dev; + + chan = dma_request_channel(mask, at_dma_filter, atslave); + if (!chan) + return NULL; + + atchan = to_at_dma_chan(chan); + atchan->per_if = dma_spec->args[0] & 0xff; + atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff; + + return chan; +} +#else +static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, + struct of_dma *of_dma) +{ + return NULL; +} +#endif /*-- Module Management -----------------------------------------------*/ @@ -1343,6 +1405,8 @@ static int __init at_dma_probe(struct platform_device *pdev) for (i = 0; i < plat_dat->nr_channels; i++) { struct at_dma_chan *atchan = &atdma->chan[i]; + atchan->mem_if = AT_DMA_MEM_IF; + atchan->per_if = AT_DMA_PER_IF; atchan->chan_common.device = &atdma->dma_common; dma_cookie_init(&atchan->chan_common); list_add_tail(&atchan->chan_common.device_node, @@ -1389,8 +1453,25 @@ static int __init at_dma_probe(struct platform_device *pdev) dma_async_device_register(&atdma->dma_common); + /* + * Do not return an error if the dmac node is not present in order to + * not break the existing way of requesting channel with + * dma_request_channel(). + */ + if (pdev->dev.of_node) { + err = of_dma_controller_register(pdev->dev.of_node, + at_dma_xlate, atdma); + if (err) { + dev_err(&pdev->dev, "could not register of_dma_controller\n"); + goto err_of_dma_controller_register; + } + } + return 0; +err_of_dma_controller_register: + dma_async_device_unregister(&atdma->dma_common); + dma_pool_destroy(atdma->dma_desc_pool); err_pool_create: platform_set_drvdata(pdev, NULL); free_irq(platform_get_irq(pdev, 0), atdma); diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h index 0eb3c1388667..c604d26fd4d3 100644 --- a/drivers/dma/at_hdmac_regs.h +++ b/drivers/dma/at_hdmac_regs.h @@ -220,6 +220,8 @@ enum atc_status { * @device: parent device * @ch_regs: memory mapped register base * @mask: channel index in a mask + * @per_if: peripheral interface + * @mem_if: memory interface * @status: transmit status information from irq/prep* functions * to tasklet (use atomic operations) * @tasklet: bottom half to finish transaction work @@ -238,6 +240,8 @@ struct at_dma_chan { struct at_dma *device; void __iomem *ch_regs; u8 mask; + u8 per_if; + u8 mem_if; unsigned long status; struct tasklet_struct tasklet; u32 save_cfg;