diff options
Diffstat (limited to 'drivers/char/hw_random/bcm2835-rng.c')
| -rw-r--r-- | drivers/char/hw_random/bcm2835-rng.c | 169 |
1 files changed, 117 insertions, 52 deletions
diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c index 574211a49549..7a84cec30c3a 100644 --- a/drivers/char/hw_random/bcm2835-rng.c +++ b/drivers/char/hw_random/bcm2835-rng.c @@ -15,6 +15,7 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/printk.h> +#include <linux/clk.h> #define RNG_CTRL 0x0 #define RNG_STATUS 0x4 @@ -29,116 +30,180 @@ #define RNG_INT_OFF 0x1 -static void __init nsp_rng_init(void __iomem *base) +struct bcm2835_rng_priv { + struct hwrng rng; + void __iomem *base; + bool mask_interrupts; + struct clk *clk; +}; + +static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng) { - u32 val; + return container_of(rng, struct bcm2835_rng_priv, rng); +} + +static inline u32 rng_readl(struct bcm2835_rng_priv *priv, u32 offset) +{ + /* MIPS chips strapped for BE will automagically configure the + * peripheral registers for CPU-native byte order. + */ + if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + return __raw_readl(priv->base + offset); + else + return readl(priv->base + offset); +} - /* mask the interrupt */ - val = readl(base + RNG_INT_MASK); - val |= RNG_INT_OFF; - writel(val, base + RNG_INT_MASK); +static inline void rng_writel(struct bcm2835_rng_priv *priv, u32 val, + u32 offset) +{ + if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) + __raw_writel(val, priv->base + offset); + else + writel(val, priv->base + offset); } static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { - void __iomem *rng_base = (void __iomem *)rng->priv; + struct bcm2835_rng_priv *priv = to_rng_priv(rng); u32 max_words = max / sizeof(u32); u32 num_words, count; - while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) { + while ((rng_readl(priv, RNG_STATUS) >> 24) == 0) { if (!wait) return 0; cpu_relax(); } - num_words = readl(rng_base + RNG_STATUS) >> 24; + num_words = rng_readl(priv, RNG_STATUS) >> 24; if (num_words > max_words) num_words = max_words; for (count = 0; count < num_words; count++) - ((u32 *)buf)[count] = readl(rng_base + RNG_DATA); + ((u32 *)buf)[count] = rng_readl(priv, RNG_DATA); return num_words * sizeof(u32); } -static struct hwrng bcm2835_rng_ops = { - .name = "bcm2835", - .read = bcm2835_rng_read, +static int bcm2835_rng_init(struct hwrng *rng) +{ + struct bcm2835_rng_priv *priv = to_rng_priv(rng); + int ret = 0; + u32 val; + + if (!IS_ERR(priv->clk)) { + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + } + + if (priv->mask_interrupts) { + /* mask the interrupt */ + val = rng_readl(priv, RNG_INT_MASK); + val |= RNG_INT_OFF; + rng_writel(priv, val, RNG_INT_MASK); + } + + /* set warm-up count & enable */ + rng_writel(priv, RNG_WARMUP_COUNT, RNG_STATUS); + rng_writel(priv, RNG_RBGEN, RNG_CTRL); + + return ret; +} + +static void bcm2835_rng_cleanup(struct hwrng *rng) +{ + struct bcm2835_rng_priv *priv = to_rng_priv(rng); + + /* disable rng hardware */ + rng_writel(priv, 0, RNG_CTRL); + + if (!IS_ERR(priv->clk)) + clk_disable_unprepare(priv->clk); +} + +struct bcm2835_rng_of_data { + bool mask_interrupts; +}; + +static const struct bcm2835_rng_of_data nsp_rng_of_data = { + .mask_interrupts = true, }; static const struct of_device_id bcm2835_rng_of_match[] = { { .compatible = "brcm,bcm2835-rng"}, - { .compatible = "brcm,bcm-nsp-rng", .data = nsp_rng_init}, - { .compatible = "brcm,bcm5301x-rng", .data = nsp_rng_init}, + { .compatible = "brcm,bcm-nsp-rng", .data = &nsp_rng_of_data }, + { .compatible = "brcm,bcm5301x-rng", .data = &nsp_rng_of_data }, + { .compatible = "brcm,bcm6368-rng"}, {}, }; static int bcm2835_rng_probe(struct platform_device *pdev) { + const struct bcm2835_rng_of_data *of_data; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; - void (*rng_setup)(void __iomem *base); const struct of_device_id *rng_id; - void __iomem *rng_base; + struct bcm2835_rng_priv *priv; + struct resource *r; int err; + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + /* map peripheral */ - rng_base = of_iomap(np, 0); - if (!rng_base) { - dev_err(dev, "failed to remap rng regs"); - return -ENODEV; - } - bcm2835_rng_ops.priv = (unsigned long)rng_base; + priv->base = devm_ioremap_resource(dev, r); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + /* Clock is optional on most platforms */ + priv->clk = devm_clk_get(dev, NULL); + + priv->rng.name = pdev->name; + priv->rng.init = bcm2835_rng_init; + priv->rng.read = bcm2835_rng_read; + priv->rng.cleanup = bcm2835_rng_cleanup; rng_id = of_match_node(bcm2835_rng_of_match, np); - if (!rng_id) { - iounmap(rng_base); + if (!rng_id) return -EINVAL; - } - /* Check for rng init function, execute it */ - rng_setup = rng_id->data; - if (rng_setup) - rng_setup(rng_base); - /* set warm-up count & enable */ - __raw_writel(RNG_WARMUP_COUNT, rng_base + RNG_STATUS); - __raw_writel(RNG_RBGEN, rng_base + RNG_CTRL); + /* Check for rng init function, execute it */ + of_data = rng_id->data; + if (of_data) + priv->mask_interrupts = of_data->mask_interrupts; /* register driver */ - err = hwrng_register(&bcm2835_rng_ops); - if (err) { + err = devm_hwrng_register(dev, &priv->rng); + if (err) dev_err(dev, "hwrng registration failed\n"); - iounmap(rng_base); - } else + else dev_info(dev, "hwrng registered\n"); return err; } -static int bcm2835_rng_remove(struct platform_device *pdev) -{ - void __iomem *rng_base = (void __iomem *)bcm2835_rng_ops.priv; - - /* disable rng hardware */ - __raw_writel(0, rng_base + RNG_CTRL); - - /* unregister driver */ - hwrng_unregister(&bcm2835_rng_ops); - iounmap(rng_base); - - return 0; -} - MODULE_DEVICE_TABLE(of, bcm2835_rng_of_match); +static struct platform_device_id bcm2835_rng_devtype[] = { + { .name = "bcm2835-rng" }, + { .name = "bcm63xx-rng" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, bcm2835_rng_devtype); + static struct platform_driver bcm2835_rng_driver = { .driver = { .name = "bcm2835-rng", .of_match_table = bcm2835_rng_of_match, }, .probe = bcm2835_rng_probe, - .remove = bcm2835_rng_remove, + .id_table = bcm2835_rng_devtype, }; module_platform_driver(bcm2835_rng_driver); |