hwrng: atmel - add new platform support for sam9x60

[linux.git] / drivers / char / hw_random / atmel-rng.c

diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c
index b3138ec26f8569c05e72c04a84295c3e00d6f54a..ecb71c4317a503a8772fb078cfec2950ce3a39d8 100644 (file)
--- 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);