--- /dev/null
+* 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";
-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
{
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;
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;
* 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;
--- /dev/null
+/*
+ * 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>");
}
}
+/*
+ * 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;
}
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,
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;
};
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff