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Subject[PATCH v4 2/2] dmaengine: at_hdmac: add device tree support
Date
Add device tree probe support for atmel at_hdmac DMA driver.
Bindings are added to specify DMA controller configuration.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
---
.../devicetree/bindings/dma/atmel-dma.txt | 14 ++++++++
drivers/dma/at_hdmac.c | 32 +++++++++++++++++++-
2 files changed, 45 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/dma/atmel-dma.txt
diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt
new file mode 100644
index 0000000..3c046ee
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt
@@ -0,0 +1,14 @@
+* Atmel Direct Memory Access Controller (DMA)
+
+Required properties:
+- compatible: Should be "atmel,<chip>-dma"
+- reg: Should contain DMA registers location and length
+- interrupts: Should contain DMA interrupt
+
+Examples:
+
+dma@ffffec00 {
+ compatible = "atmel,at91sam9g45-dma";
+ reg = <0xffffec00 0x200>;
+ interrupts = <21>;
+};
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index d1869c5..f3cb4a0 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -23,6 +23,8 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>

#include "at_hdmac_regs.h"

@@ -1175,6 +1177,20 @@ static void atc_free_chan_resources(struct dma_chan *chan)

/*-- Module Management -----------------------------------------------*/

+#if defined(CONFIG_OF)
+static const struct of_device_id atmel_dma_dt_ids[] = {
+ {
+ .compatible = "atmel,at91sam9rl-dma",
+ .data = (void *)ATDMA_DEVTYPE_SAM9RL
+ }, {
+ .compatible = "atmel,at91sam9g45-dma",
+ .data = (void *)ATDMA_DEVTYPE_SAM9G45
+ }, { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids);
+#endif
+
static struct platform_device_id atdma_devtypes[] = {
{
.name = "at91sam9rl_dma",
@@ -1187,6 +1203,19 @@ static struct platform_device_id atdma_devtypes[] = {
}
};

+static inline enum atdma_devtype __init at_dma_get_driver_data(
+ struct platform_device *pdev)
+{
+ if (pdev->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node);
+ if (match == NULL)
+ return ATDMA_DEVTYPE_UNDEFINED;
+ return (enum atdma_devtype)match->data;
+ }
+ return platform_get_device_id(pdev)->driver_data;
+}
+
/**
* at_dma_off - disable DMA controller
* @atdma: the Atmel HDAMC device
@@ -1218,7 +1247,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
dma_cap_set(DMA_MEMCPY, cap_mask);

/* get DMA parameters from controller type */
- atdmatype = platform_get_device_id(pdev)->driver_data;
+ atdmatype = at_dma_get_driver_data(pdev);

switch (atdmatype) {
case ATDMA_DEVTYPE_SAM9RL:
@@ -1526,6 +1555,7 @@ static struct platform_driver at_dma_driver = {
.driver = {
.name = "at_hdmac",
.pm = &at_dma_dev_pm_ops,
+ .of_match_table = of_match_ptr(atmel_dma_dt_ids),
},
};

--
1.7.5.4


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