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>

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>
Alexander Clouter · Herbert Xu
1 parent 1907da78bf
Showing 2 changed files with 40 additions and 2 deletions Side-by-side Diff
Documentation/devicetree/bindings/hwrng/timeriomem_rng.txt
drivers/char/hw_random/timeriomem-rng.c
+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>;
+};
@@ -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 @@
 	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;
 	}
  
@@ -125,8 +126,20 @@
  
 	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) {
 		dev_err(&pdev->dev, "period is less than one jiffy\n");
  
@@ -202,10 +215,17 @@
 	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,
	1	+HWRNG support for the timeriomem_rng driver
	2	+
	3	+Required properties:
	4	+- compatible : "timeriomem_rng"
	5	+- reg : base address to sample from
	6	+- period : wait time in microseconds to use between samples
	7	+
	8	+N.B. currently 'reg' must be four bytes wide and aligned
	9	+
	10	+Example:
	11	+
	12	+hwrng@44 {
	13	+ #address-cells = <1>;
	14	+ #size-cells = <1>;
	15	+ compatible = "timeriomem_rng";
	16	+ reg = <0x44 0x04>;
	17	+ period = <1000000>;
	18	+};
...	...	@@ -23,6 +23,7 @@
23	23	#include <linux/module.h>
24	24	#include <linux/kernel.h>
25	25	#include <linux/platform_device.h>
	26	+#include <linux/of.h>
26	27	#include <linux/hw_random.h>
27	28	#include <linux/io.h>
28	29	#include <linux/slab.h>
...	...	@@ -101,7 +102,7 @@
101	102	int err = 0;
102	103	int period;
103	104
104		- if (!pdata) {
	105	+ if (!pdev->dev.of_node && !pdata) {
105	106	dev_err(&pdev->dev, "timeriomem_rng_data is missing\n");
106	107	return -EINVAL;
107	108	}
108	109
...	...	@@ -125,8 +126,20 @@
125	126
126	127	platform_set_drvdata(pdev, priv);
127	128
128		- period = pdata->period;
	129	+ if (pdev->dev.of_node) {
	130	+ int i;
129	131
	132	+ if (!of_property_read_u32(pdev->dev.of_node,
	133	+ "period", &i))
	134	+ period = i;
	135	+ else {
	136	+ dev_err(&pdev->dev, "missing period\n");
	137	+ err = -EINVAL;
	138	+ goto out_free;
	139	+ }
	140	+ } else
	141	+ period = pdata->period;
	142	+
130	143	priv->period = usecs_to_jiffies(period);
131	144	if (priv->period < 1) {
132	145	dev_err(&pdev->dev, "period is less than one jiffy\n");
133	146
...	...	@@ -202,10 +215,17 @@
202	215	return 0;
203	216	}
204	217
	218	+static const struct of_device_id timeriomem_rng_match[] = {
	219	+ { .compatible = "timeriomem_rng" },
	220	+ {},
	221	+};
	222	+MODULE_DEVICE_TABLE(of, timeriomem_rng_match);
	223	+
205	224	static struct platform_driver timeriomem_rng_driver = {
206	225	.driver = {
207	226	.name = "timeriomem_rng",
208	227	.owner = THIS_MODULE,
	228	+ .of_match_table = timeriomem_rng_match,
209	229	},
210	230	.probe = timeriomem_rng_probe,
211	231	.remove = timeriomem_rng_remove,