diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/hw_random/atmel-rng.c | 39 |
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); |