dmaengine: ste_dma40: Supply full Device Tree parsing support
Using the new DMA DT bindings and API, we can register the DMA40 driver
as Device Tree capable. Now, when a client attempts to allocate a
channel using the DMA DT bindings via its own node, we are able to parse
the request and allocate a channel in the correct manner.
Cc: Dan Williams <djbw@fb.com>
Cc: Per Forlin <per.forlin@stericsson.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: devicetree-discuss@lists.ozlabs.org
Acked-by: Vinod Koul <vinod.koul@intel.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 495e886..5e9f6d6 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -18,6 +18,7 @@
#include <linux/pm_runtime.h>
#include <linux/err.h>
#include <linux/of.h>
+#include <linux/of_dma.h>
#include <linux/amba/bus.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_data/dma-ste-dma40.h>
@@ -2422,6 +2423,50 @@
__d40_set_prio_rt(d40c, d40c->dma_cfg.dev_type, false);
}
+#define D40_DT_FLAGS_MODE(flags) ((flags >> 0) & 0x1)
+#define D40_DT_FLAGS_DIR(flags) ((flags >> 1) & 0x1)
+#define D40_DT_FLAGS_BIG_ENDIAN(flags) ((flags >> 2) & 0x1)
+#define D40_DT_FLAGS_FIXED_CHAN(flags) ((flags >> 3) & 0x1)
+
+static struct dma_chan *d40_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct stedma40_chan_cfg cfg;
+ dma_cap_mask_t cap;
+ u32 flags;
+
+ memset(&cfg, 0, sizeof(struct stedma40_chan_cfg));
+
+ dma_cap_zero(cap);
+ dma_cap_set(DMA_SLAVE, cap);
+
+ cfg.dev_type = dma_spec->args[0];
+ flags = dma_spec->args[2];
+
+ switch (D40_DT_FLAGS_MODE(flags)) {
+ case 0: cfg.mode = STEDMA40_MODE_LOGICAL; break;
+ case 1: cfg.mode = STEDMA40_MODE_PHYSICAL; break;
+ }
+
+ switch (D40_DT_FLAGS_DIR(flags)) {
+ case 0:
+ cfg.dir = STEDMA40_MEM_TO_PERIPH;
+ cfg.dst_info.big_endian = D40_DT_FLAGS_BIG_ENDIAN(flags);
+ break;
+ case 1:
+ cfg.dir = STEDMA40_PERIPH_TO_MEM;
+ cfg.src_info.big_endian = D40_DT_FLAGS_BIG_ENDIAN(flags);
+ break;
+ }
+
+ if (D40_DT_FLAGS_FIXED_CHAN(flags)) {
+ cfg.phy_channel = dma_spec->args[1];
+ cfg.use_fixed_channel = true;
+ }
+
+ return dma_request_channel(cap, stedma40_filter, &cfg);
+}
+
/* DMA ENGINE functions */
static int d40_alloc_chan_resources(struct dma_chan *chan)
{
@@ -3638,6 +3683,13 @@
d40_hw_init(base);
+ if (np) {
+ err = of_dma_controller_register(np, d40_xlate, NULL);
+ if (err && err != -ENODEV)
+ dev_err(&pdev->dev,
+ "could not register of_dma_controller\n");
+ }
+
dev_info(base->dev, "initialized\n");
return 0;