hwrng: timeriomem - added devicetree hooks

This patch allows timeriomem_rng to be used via devicetree.

Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/Documentation/devicetree/bindings/hwrng/timeriomem_rng.txt b/Documentation/devicetree/bindings/hwrng/timeriomem_rng.txt
new file mode 100644 (file)
index 0000000..6616d15
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwrng/timeriomem_rng.txt
@@ -0,0 +1,18 @@
+HWRNG support for the timeriomem_rng driver
+
+Required properties:
+- compatible : "timeriomem_rng"
+- reg : base address to sample from
+- period : wait time in microseconds to use between samples
+
+N.B. currently 'reg' must be four bytes wide and aligned
+
+Example:
+
+hwrng@44 {
+       #address-cells = <1>;
+       #size-cells = <1>;
+       compatible = "timeriomem_rng";
+       reg = <0x44 0x04>;
+       period = <1000000>;
+};

diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c
index 9dd2cad..3e75737 100644 (file)
--- a/drivers/char/hw_random/timeriomem-rng.c
+++ b/drivers/char/hw_random/timeriomem-rng.c
@@ -23,6 +23,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>
+#include <linux/of.h>
 #include <linux/hw_random.h>
 #include <linux/io.h>
 #include <linux/slab.h>
@@ -101,7 +102,7 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
        int err = 0;
        int period;
 
-       if (!pdata) {
+       if (!pdev->dev.of_node && !pdata) {
                dev_err(&pdev->dev, "timeriomem_rng_data is missing\n");
                return -EINVAL;
        }
@@ -125,7 +126,19 @@ static int timeriomem_rng_probe(struct platform_device *pdev)
 
        platform_set_drvdata(pdev, priv);
 
-       period = pdata->period;
+       if (pdev->dev.of_node) {
+               int i;
+
+               if (!of_property_read_u32(pdev->dev.of_node,
+                                               "period", &i))
+                       period = i;
+               else {
+                       dev_err(&pdev->dev, "missing period\n");
+                       err = -EINVAL;
+                       goto out_free;
+               }
+       } else
+               period = pdata->period;
 
        priv->period = usecs_to_jiffies(period);
        if (priv->period < 1) {
@@ -202,10 +215,17 @@ static int timeriomem_rng_remove(struct platform_device *pdev)
        return 0;
 }
 
+static const struct of_device_id timeriomem_rng_match[] = {
+       { .compatible = "timeriomem_rng" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, timeriomem_rng_match);
+
 static struct platform_driver timeriomem_rng_driver = {
        .driver = {
                .name           = "timeriomem_rng",
                .owner          = THIS_MODULE,
+               .of_match_table = timeriomem_rng_match,
        },
        .probe          = timeriomem_rng_probe,
        .remove         = timeriomem_rng_remove,