Required properties:
- compatible: "snps,dma-spear1340"
- reg: Address range of the DMAC registers
-- interrupt-parent: Should be the phandle for the interrupt controller
- that services interrupts for this device
- interrupt: Should contain the DMAC interrupt number
-- nr_channels: Number of channels supported by hardware
-- is_private: The device channels should be marked as private and not for by the
- general purpose DMA channel allocator. False if not passed.
+- dma-channels: Number of channels supported by hardware
+- dma-requests: Number of DMA request lines supported, up to 16
+- dma-masters: Number of AHB masters supported by the controller
+- #dma-cells: must be <3>
- chan_allocation_order: order of allocation of channel, 0 (default): ascending,
1: descending
- chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1:
increase from chan n->0
- block_size: Maximum block size supported by the controller
-- nr_masters: Number of AHB masters supported by the controller
- data_width: Maximum data width supported by hardware per AHB master
(0 - 8bits, 1 - 16bits, ..., 5 - 256bits)
-- slave_info:
- - bus_id: name of this device channel, not just a device name since
- devices may have more than one channel e.g. "foo_tx". For using the
- dw_generic_filter(), slave drivers must pass exactly this string as
- param to filter function.
- - cfg_hi: Platform-specific initializer for the CFG_HI register
- - cfg_lo: Platform-specific initializer for the CFG_LO register
- - src_master: src master for transfers on allocated channel.
- - dst_master: dest master for transfers on allocated channel.
+
+
+Optional properties:
+- interrupt-parent: Should be the phandle for the interrupt controller
+ that services interrupts for this device
+- is_private: The device channels should be marked as private and not for by the
+ general purpose DMA channel allocator. False if not passed.
Example:
- dma@fc000000 {
+ dmahost: dma@fc000000 {
compatible = "snps,dma-spear1340";
reg = <0xfc000000 0x1000>;
interrupt-parent = <&vic1>;
interrupts = <12>;
- nr_channels = <8>;
+ dma-channels = <8>;
+ dma-requests = <16>;
+ dma-masters = <2>;
+ #dma-cells = <3>;
chan_allocation_order = <1>;
chan_priority = <1>;
block_size = <0xfff>;
- nr_masters = <2>;
data_width = <3 3 0 0>;
+ };
- slave_info {
- uart0-tx {
- bus_id = "uart0-tx";
- cfg_hi = <0x4000>; /* 0x8 << 11 */
- cfg_lo = <0>;
- src_master = <0>;
- dst_master = <1>;
- };
- spi0-tx {
- bus_id = "spi0-tx";
- cfg_hi = <0x2000>; /* 0x4 << 11 */
- cfg_lo = <0>;
- src_master = <0>;
- dst_master = <0>;
- };
- };
+DMA clients connected to the Designware DMA controller must use the format
+described in the dma.txt file, using a four-cell specifier for each channel.
+The four cells in order are:
+
+1. A phandle pointing to the DMA controller
+2. The DMA request line number
+3. Source master for transfers on allocated channel
+4. Destination master for transfers on allocated channel
+
+Example:
+
+ serial@e0000000 {
+ compatible = "arm,pl011", "arm,primecell";
+ reg = <0xe0000000 0x1000>;
+ interrupts = <0 35 0x4>;
+ status = "disabled";
+ dmas = <&dmahost 12 0 1>,
+ <&dmahost 13 0 1 0>;
+ dma-names = "rx", "rx";
};
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
+#include <linux/of_dma.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/platform_device.h>
if (dwc->initialized == true)
return;
- if (dws) {
+ if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
+ /* autoconfigure based on request line from DT */
+ if (dwc->direction == DMA_MEM_TO_DEV)
+ cfghi = DWC_CFGH_DST_PER(dwc->request_line);
+ else if (dwc->direction == DMA_DEV_TO_MEM)
+ cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
+ } else if (dws) {
/*
* We need controller-specific data to set up slave
* transfers.
dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
}
-bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
+struct dw_dma_filter_args {
+ struct dw_dma *dw;
+ unsigned int req;
+ unsigned int src;
+ unsigned int dst;
+};
+
+static bool dw_dma_generic_filter(struct dma_chan *chan, void *param)
{
+ struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma *dw = to_dw_dma(chan->device);
- static struct dw_dma *last_dw;
- static char *last_bus_id;
- int i = -1;
+ struct dw_dma_filter_args *fargs = param;
+ struct dw_dma_slave *dws = &dwc->slave;
- /*
- * dmaengine framework calls this routine for all channels of all dma
- * controller, until true is returned. If 'param' bus_id is not
- * registered with a dma controller (dw), then there is no need of
- * running below function for all channels of dw.
- *
- * This block of code does this by saving the parameters of last
- * failure. If dw and param are same, i.e. trying on same dw with
- * different channel, return false.
- */
- if ((last_dw == dw) && (last_bus_id == param))
- return false;
- /*
- * Return true:
- * - If dw_dma's platform data is not filled with slave info, then all
- * dma controllers are fine for transfer.
- * - Or if param is NULL
- */
- if (!dw->sd || !param)
- return true;
+ /* ensure the device matches our channel */
+ if (chan->device != &fargs->dw->dma)
+ return false;
- while (++i < dw->sd_count) {
- if (!strcmp(dw->sd[i].bus_id, param)) {
- chan->private = &dw->sd[i];
- last_dw = NULL;
- last_bus_id = NULL;
+ dws->dma_dev = dw->dma.dev;
+ dws->cfg_hi = ~0;
+ dws->cfg_lo = ~0;
+ dws->src_master = fargs->src;
+ dws->dst_master = fargs->dst;
- return true;
- }
- }
+ dwc->request_line = fargs->req;
- last_dw = dw;
- last_bus_id = param;
- return false;
+ chan->private = dws;
+
+ return true;
+}
+
+static struct dma_chan *dw_dma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct dw_dma *dw = ofdma->of_dma_data;
+ struct dw_dma_filter_args fargs = {
+ .dw = dw,
+ };
+ dma_cap_mask_t cap;
+
+ if (dma_spec->args_count != 3)
+ return NULL;
+
+ fargs.req = be32_to_cpup(dma_spec->args+0);
+ fargs.src = be32_to_cpup(dma_spec->args+1);
+ fargs.dst = be32_to_cpup(dma_spec->args+2);
+
+ if (WARN_ON(fargs.req >= DW_DMA_MAX_NR_REQUESTS ||
+ fargs.src >= dw->nr_masters ||
+ fargs.dst >= dw->nr_masters))
+ return NULL;
+
+ dma_cap_zero(cap);
+ dma_cap_set(DMA_SLAVE, cap);
+
+ /* TODO: there should be a simpler way to do this */
+ return dma_request_channel(cap, dw_dma_generic_filter, &fargs);
}
-EXPORT_SYMBOL(dw_dma_generic_filter);
/* --------------------- Cyclic DMA API extensions -------------------- */
static struct dw_dma_platform_data *
dw_dma_parse_dt(struct platform_device *pdev)
{
- struct device_node *sn, *cn, *np = pdev->dev.of_node;
+ struct device_node *np = pdev->dev.of_node;
struct dw_dma_platform_data *pdata;
- struct dw_dma_slave *sd;
u32 tmp, arr[4];
if (!np) {
if (!pdata)
return NULL;
- if (of_property_read_u32(np, "nr_channels", &pdata->nr_channels))
+ if (of_property_read_u32(np, "dma-channels", &pdata->nr_channels))
return NULL;
if (of_property_read_bool(np, "is_private"))
if (!of_property_read_u32(np, "block_size", &tmp))
pdata->block_size = tmp;
- if (!of_property_read_u32(np, "nr_masters", &tmp)) {
+ if (!of_property_read_u32(np, "dma-masters", &tmp)) {
if (tmp > 4)
return NULL;
for (tmp = 0; tmp < pdata->nr_masters; tmp++)
pdata->data_width[tmp] = arr[tmp];
- /* parse slave data */
- sn = of_find_node_by_name(np, "slave_info");
- if (!sn)
- return pdata;
-
- /* calculate number of slaves */
- tmp = of_get_child_count(sn);
- if (!tmp)
- return NULL;
-
- sd = devm_kzalloc(&pdev->dev, sizeof(*sd) * tmp, GFP_KERNEL);
- if (!sd)
- return NULL;
-
- pdata->sd = sd;
- pdata->sd_count = tmp;
-
- for_each_child_of_node(sn, cn) {
- sd->dma_dev = &pdev->dev;
- of_property_read_string(cn, "bus_id", &sd->bus_id);
- of_property_read_u32(cn, "cfg_hi", &sd->cfg_hi);
- of_property_read_u32(cn, "cfg_lo", &sd->cfg_lo);
- if (!of_property_read_u32(cn, "src_master", &tmp))
- sd->src_master = tmp;
-
- if (!of_property_read_u32(cn, "dst_master", &tmp))
- sd->dst_master = tmp;
- sd++;
- }
-
return pdata;
}
#else
clk_prepare_enable(dw->clk);
dw->regs = regs;
- dw->sd = pdata->sd;
- dw->sd_count = pdata->sd_count;
/* get hardware configuration parameters */
if (autocfg) {
dma_async_device_register(&dw->dma);
+ if (pdev->dev.of_node) {
+ err = of_dma_controller_register(pdev->dev.of_node,
+ dw_dma_xlate, dw);
+ if (err && err != -ENODEV)
+ dev_err(&pdev->dev,
+ "could not register of_dma_controller\n");
+ }
+
return 0;
}
struct dw_dma *dw = platform_get_drvdata(pdev);
struct dw_dma_chan *dwc, *_dwc;
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
dw_dma_off(dw);
dma_async_device_unregister(&dw->dma);
projects / firefly-linux-kernel-4.4.55.git / commitdiff