diff options
| -rw-r--r-- | Documentation/devicetree/bindings/dma/shdma.txt | 75 | ||||
| -rw-r--r-- | drivers/dma/sh/Makefile | 2 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma-base.c | 26 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma-of.c | 82 | ||||
| -rw-r--r-- | drivers/dma/sh/shdma.c | 31 | ||||
| -rw-r--r-- | include/linux/shdma-base.h | 2 |
6 files changed, 205 insertions, 13 deletions
diff --git a/Documentation/devicetree/bindings/dma/shdma.txt b/Documentation/devicetree/bindings/dma/shdma.txt new file mode 100644 index 00000000000..c15994aa193 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/shdma.txt @@ -0,0 +1,75 @@ +* SHDMA Device Tree bindings + +Sh-/r-mobile and r-car systems often have multiple identical DMA controller +instances, capable of serving any of a common set of DMA slave devices, using +the same configuration. To describe this topology we require all compatible +SHDMA DT nodes to be placed under a DMA multiplexer node. All such compatible +DMAC instances have the same number of channels and use the same DMA +descriptors. Therefore respective DMA DT bindings can also all be placed in the +multiplexer node. Even if there is only one such DMAC instance on a system, it +still has to be placed under such a multiplexer node. + +* DMA multiplexer + +Required properties: +- compatible: should be "renesas,shdma-mux" +- #dma-cells: should be <1>, see "dmas" property below + +Optional properties (currently unused): +- dma-channels: number of DMA channels +- dma-requests: number of DMA request signals + +* DMA controller + +Required properties: +- compatible: should be "renesas,shdma" + +Example: + dmac: dma-mux0 { + compatible = "renesas,shdma-mux"; + #dma-cells = <1>; + dma-channels = <6>; + dma-requests = <256>; + reg = <0 0>; /* Needed for AUXDATA */ + #address-cells = <1>; + #size-cells = <1>; + ranges; + + dma0: shdma@fe008020 { + compatible = "renesas,shdma"; + reg = <0xfe008020 0x270>, + <0xfe009000 0xc>; + interrupt-parent = <&gic>; + interrupts = <0 34 4 + 0 28 4 + 0 29 4 + 0 30 4 + 0 31 4 + 0 32 4 + 0 33 4>; + interrupt-names = "error", + "ch0", "ch1", "ch2", "ch3", + "ch4", "ch5"; + }; + + dma1: shdma@fe018020 { + ... + }; + + dma2: shdma@fe028020 { + ... + }; + }; + +* DMA client + +Required properties: +- dmas: a list of <[DMA multiplexer phandle] [MID/RID value]> pairs, + where MID/RID values are fixed handles, specified in the SoC + manual +- dma-names: a list of DMA channel names, one per "dmas" entry + +Example: + dmas = <&dmac 0xd1 + &dmac 0xd2>; + dma-names = "tx", "rx"; diff --git a/drivers/dma/sh/Makefile b/drivers/dma/sh/Makefile index c07ca4612e4..c962138dde9 100644 --- a/drivers/dma/sh/Makefile +++ b/drivers/dma/sh/Makefile @@ -1,3 +1,3 @@ -obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o +obj-$(CONFIG_SH_DMAE_BASE) += shdma-base.o shdma-of.o obj-$(CONFIG_SH_DMAE) += shdma.o obj-$(CONFIG_SUDMAC) += sudmac.o diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c index 4acb85a1025..28ca3612163 100644 --- a/drivers/dma/sh/shdma-base.c +++ b/drivers/dma/sh/shdma-base.c @@ -175,7 +175,18 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) { struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); const struct shdma_ops *ops = sdev->ops; - int ret; + int ret, match; + + if (schan->dev->of_node) { + match = schan->hw_req; + ret = ops->set_slave(schan, match, true); + if (ret < 0) + return ret; + + slave_id = schan->slave_id; + } else { + match = slave_id; + } if (slave_id < 0 || slave_id >= slave_num) return -EINVAL; @@ -183,7 +194,7 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) if (test_and_set_bit(slave_id, shdma_slave_used)) return -EBUSY; - ret = ops->set_slave(schan, slave_id, false); + ret = ops->set_slave(schan, match, false); if (ret < 0) { clear_bit(slave_id, shdma_slave_used); return ret; @@ -206,23 +217,26 @@ static int shdma_setup_slave(struct shdma_chan *schan, int slave_id) * services would have to provide their own filters, which first would check * the device driver, similar to how other DMAC drivers, e.g., sa11x0-dma.c, do * this, and only then, in case of a match, call this common filter. + * NOTE 2: This filter function is also used in the DT case by shdma_of_xlate(). + * In that case the MID-RID value is used for slave channel filtering and is + * passed to this function in the "arg" parameter. */ bool shdma_chan_filter(struct dma_chan *chan, void *arg) { struct shdma_chan *schan = to_shdma_chan(chan); struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device); const struct shdma_ops *ops = sdev->ops; - int slave_id = (int)arg; + int match = (int)arg; int ret; - if (slave_id < 0) + if (match < 0) /* No slave requested - arbitrary channel */ return true; - if (slave_id >= slave_num) + if (!schan->dev->of_node && match >= slave_num) return false; - ret = ops->set_slave(schan, slave_id, true); + ret = ops->set_slave(schan, match, true); if (ret < 0) return false; diff --git a/drivers/dma/sh/shdma-of.c b/drivers/dma/sh/shdma-of.c new file mode 100644 index 00000000000..11bcb05cd79 --- /dev/null +++ b/drivers/dma/sh/shdma-of.c @@ -0,0 +1,82 @@ +/* + * SHDMA Device Tree glue + * + * Copyright (C) 2013 Renesas Electronics Inc. + * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de> + * + * This is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + */ + +#include <linux/dmaengine.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_dma.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/shdma-base.h> + +#define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan) + +static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + u32 id = dma_spec->args[0]; + dma_cap_mask_t mask; + struct dma_chan *chan; + + if (dma_spec->args_count != 1) + return NULL; + + dma_cap_zero(mask); + /* Only slave DMA channels can be allocated via DT */ + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_channel(mask, shdma_chan_filter, (void *)id); + if (chan) + to_shdma_chan(chan)->hw_req = id; + + return chan; +} + +static int shdma_of_probe(struct platform_device *pdev) +{ + const struct of_dev_auxdata *lookup = pdev->dev.platform_data; + int ret; + + if (!lookup) + return -EINVAL; + + ret = of_dma_controller_register(pdev->dev.of_node, + shdma_of_xlate, pdev); + if (ret < 0) + return ret; + + ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev); + if (ret < 0) + of_dma_controller_free(pdev->dev.of_node); + + return ret; +} + +static const struct of_device_id shdma_of_match[] = { + { .compatible = "renesas,shdma-mux", }, + { } +}; +MODULE_DEVICE_TABLE(of, sh_dmae_of_match); + +static struct platform_driver shdma_of = { + .driver = { + .owner = THIS_MODULE, + .name = "shdma-of", + .of_match_table = shdma_of_match, + }, + .probe = shdma_of_probe, +}; + +module_platform_driver(shdma_of); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("SH-DMA driver DT glue"); +MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>"); diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c index a5a1887c34b..b67f45f5c27 100644 --- a/drivers/dma/sh/shdma.c +++ b/drivers/dma/sh/shdma.c @@ -301,20 +301,32 @@ static void sh_dmae_setup_xfer(struct shdma_chan *schan, } } +/* + * Find a slave channel configuration from the contoller list by either a slave + * ID in the non-DT case, or by a MID/RID value in the DT case + */ static const struct sh_dmae_slave_config *dmae_find_slave( - struct sh_dmae_chan *sh_chan, int slave_id) + struct sh_dmae_chan *sh_chan, int match) { struct sh_dmae_device *shdev = to_sh_dev(sh_chan); struct sh_dmae_pdata *pdata = shdev->pdata; const struct sh_dmae_slave_config *cfg; int i; - if (slave_id >= SH_DMA_SLAVE_NUMBER) - return NULL; + if (!sh_chan->shdma_chan.dev->of_node) { + if (match >= SH_DMA_SLAVE_NUMBER) + return NULL; - for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) - if (cfg->slave_id == slave_id) - return cfg; + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) + if (cfg->slave_id == match) + return cfg; + } else { + for (i = 0, cfg = pdata->slave; i < pdata->slave_num; i++, cfg++) + if (cfg->mid_rid == match) { + sh_chan->shdma_chan.slave_id = cfg->slave_id; + return cfg; + } + } return NULL; } @@ -920,11 +932,18 @@ static int sh_dmae_remove(struct platform_device *pdev) return 0; } +static const struct of_device_id sh_dmae_of_match[] = { + { .compatible = "renesas,shdma", }, + { } +}; +MODULE_DEVICE_TABLE(of, sh_dmae_of_match); + static struct platform_driver sh_dmae_driver = { .driver = { .owner = THIS_MODULE, .pm = &sh_dmae_pm, .name = SH_DMAE_DRV_NAME, + .of_match_table = sh_dmae_of_match, }, .remove = sh_dmae_remove, .shutdown = sh_dmae_shutdown, diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h index 9a938971bc4..382cf710ca9 100644 --- a/include/linux/shdma-base.h +++ b/include/linux/shdma-base.h @@ -68,6 +68,8 @@ struct shdma_chan { int id; /* Raw id of this channel */ int irq; /* Channel IRQ */ int slave_id; /* Client ID for slave DMA */ + int hw_req; /* DMA request line for slave DMA - same + * as MID/RID, used with DT */ enum shdma_pm_state pm_state; }; |