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-rw-r--r--drivers/char/hw_random/atmel-rng.c39
1 files changed, 37 insertions, 2 deletions
diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index b3138ec26f85..ecb71c4317a5 100644
--- a/drivers/char/hw_random/atmel-rng.c
+++ b/drivers/char/hw_random/atmel-rng.c
@@ -14,14 +14,22 @@
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/hw_random.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#define TRNG_CR 0x00
+#define TRNG_MR 0x04
#define TRNG_ISR 0x1c
#define TRNG_ODATA 0x50
#define TRNG_KEY 0x524e4700 /* RNG */
+#define TRNG_HALFR BIT(0) /* generate RN every 168 cycles */
+
+struct atmel_trng_data {
+ bool has_half_rate;
+};
+
struct atmel_trng {
struct clk *clk;
void __iomem *base;
@@ -62,6 +70,7 @@ static void atmel_trng_disable(struct atmel_trng *trng)
static int atmel_trng_probe(struct platform_device *pdev)
{
struct atmel_trng *trng;
+ const struct atmel_trng_data *data;
int ret;
trng = devm_kzalloc(&pdev->dev, sizeof(*trng), GFP_KERNEL);
@@ -75,6 +84,17 @@ static int atmel_trng_probe(struct platform_device *pdev)
trng->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(trng->clk))
return PTR_ERR(trng->clk);
+ data = of_device_get_match_data(&pdev->dev);
+ if (!data)
+ return -ENODEV;
+
+ if (data->has_half_rate) {
+ unsigned long rate = clk_get_rate(trng->clk);
+
+ /* if peripheral clk is above 100MHz, set HALFR */
+ if (rate > 100000000)
+ writel(TRNG_HALFR, trng->base + TRNG_MR);
+ }
ret = clk_prepare_enable(trng->clk);
if (ret)
@@ -139,9 +159,24 @@ static const struct dev_pm_ops atmel_trng_pm_ops = {
};
#endif /* CONFIG_PM */
+static const struct atmel_trng_data at91sam9g45_config = {
+ .has_half_rate = false,
+};
+
+static const struct atmel_trng_data sam9x60_config = {
+ .has_half_rate = true,
+};
+
static const struct of_device_id atmel_trng_dt_ids[] = {
- { .compatible = "atmel,at91sam9g45-trng" },
- { /* sentinel */ }
+ {
+ .compatible = "atmel,at91sam9g45-trng",
+ .data = &at91sam9g45_config,
+ }, {
+ .compatible = "microchip,sam9x60-trng",
+ .data = &sam9x60_config,
+ }, {
+ /* sentinel */
+ }
};
MODULE_DEVICE_TABLE(of, atmel_trng_dt_ids);