--- /dev/null
+From e9c0fd87b6169baf5bd10293a85675d505086191 Mon Sep 17 00:00:00 2001
+From: Stefan Wahren <wahrenst@gmx.net>
+Date: Sat, 4 May 2019 17:06:15 +0200
+Subject: [PATCH] hwrng: iproc-rng200: Add BCM2838 support
+
+The HWRNG on the BCM2838 is compatible to iproc-rng200, so add the
+support to this driver instead of bcm2835-rng.
+
+Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
+---
+ drivers/char/hw_random/Kconfig | 4 +-
+ drivers/char/hw_random/iproc-rng200.c | 81 +++++++++++++++++++++++++--
+ 2 files changed, 79 insertions(+), 6 deletions(-)
+
+--- a/drivers/char/hw_random/Kconfig
++++ b/drivers/char/hw_random/Kconfig
+@@ -89,11 +89,11 @@ config HW_RANDOM_BCM2835
+
+ config HW_RANDOM_IPROC_RNG200
+ tristate "Broadcom iProc/STB RNG200 support"
+- depends on ARCH_BCM_IPROC || ARCH_BRCMSTB
++ depends on ARCH_BCM_IPROC || ARCH_BCM2835 || ARCH_BRCMSTB
+ default HW_RANDOM
+ ---help---
+ This driver provides kernel-side support for the RNG200
+- hardware found on the Broadcom iProc and STB SoCs.
++ hardware found on the Broadcom iProc, BCM2838 and STB SoCs.
+
+ To compile this driver as a module, choose M here: the
+ module will be called iproc-rng200
+--- a/drivers/char/hw_random/iproc-rng200.c
++++ b/drivers/char/hw_random/iproc-rng200.c
+@@ -29,6 +29,7 @@
+ #define RNG_CTRL_RNG_RBGEN_MASK 0x00001FFF
+ #define RNG_CTRL_RNG_RBGEN_ENABLE 0x00000001
+ #define RNG_CTRL_RNG_RBGEN_DISABLE 0x00000000
++#define RNG_CTRL_RNG_DIV_CTRL_SHIFT 13
+
+ #define RNG_SOFT_RESET_OFFSET 0x04
+ #define RNG_SOFT_RESET 0x00000001
+@@ -36,16 +37,23 @@
+ #define RBG_SOFT_RESET_OFFSET 0x08
+ #define RBG_SOFT_RESET 0x00000001
+
++#define RNG_TOTAL_BIT_COUNT_OFFSET 0x0C
++
++#define RNG_TOTAL_BIT_COUNT_THRESHOLD_OFFSET 0x10
++
+ #define RNG_INT_STATUS_OFFSET 0x18
+ #define RNG_INT_STATUS_MASTER_FAIL_LOCKOUT_IRQ_MASK 0x80000000
+ #define RNG_INT_STATUS_STARTUP_TRANSITIONS_MET_IRQ_MASK 0x00020000
+ #define RNG_INT_STATUS_NIST_FAIL_IRQ_MASK 0x00000020
+ #define RNG_INT_STATUS_TOTAL_BITS_COUNT_IRQ_MASK 0x00000001
+
++#define RNG_INT_ENABLE_OFFSET 0x1C
++
+ #define RNG_FIFO_DATA_OFFSET 0x20
+
+ #define RNG_FIFO_COUNT_OFFSET 0x24
+ #define RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK 0x000000FF
++#define RNG_FIFO_COUNT_RNG_FIFO_THRESHOLD_SHIFT 8
+
+ struct iproc_rng200_dev {
+ struct hwrng rng;
+@@ -166,6 +174,64 @@ static int iproc_rng200_init(struct hwrn
+ return 0;
+ }
+
++static int bcm2838_rng200_read(struct hwrng *rng, void *buf, size_t max,
++ bool wait)
++{
++ struct iproc_rng200_dev *priv = to_rng_priv(rng);
++ u32 max_words = max / sizeof(u32);
++ u32 num_words, count, val;
++
++ /* ensure warm up period has elapsed */
++ while (1) {
++ val = ioread32(priv->base + RNG_TOTAL_BIT_COUNT_OFFSET);
++ if (val > 16)
++ break;
++ cpu_relax();
++ }
++
++ /* ensure fifo is not empty */
++ while (1) {
++ num_words = ioread32(priv->base + RNG_FIFO_COUNT_OFFSET) &
++ RNG_FIFO_COUNT_RNG_FIFO_COUNT_MASK;
++ if (num_words)
++ break;
++ if (!wait)
++ return 0;
++ cpu_relax();
++ }
++
++ if (num_words > max_words)
++ num_words = max_words;
++
++ for (count = 0; count < num_words; count++) {
++ ((u32 *)buf)[count] = ioread32(priv->base +
++ RNG_FIFO_DATA_OFFSET);
++ }
++
++ return num_words * sizeof(u32);
++}
++
++static int bcm2838_rng200_init(struct hwrng *rng)
++{
++ struct iproc_rng200_dev *priv = to_rng_priv(rng);
++ uint32_t val;
++
++ if (ioread32(priv->base + RNG_CTRL_OFFSET) & RNG_CTRL_RNG_RBGEN_MASK)
++ return 0;
++
++ /* initial numbers generated are "less random" so will be discarded */
++ val = 0x40000;
++ iowrite32(val, priv->base + RNG_TOTAL_BIT_COUNT_THRESHOLD_OFFSET);
++ /* min fifo count to generate full interrupt */
++ val = 2 << RNG_FIFO_COUNT_RNG_FIFO_THRESHOLD_SHIFT;
++ iowrite32(val, priv->base + RNG_FIFO_COUNT_OFFSET);
++ /* enable the rng - 1Mhz sample rate */
++ val = (0x3 << RNG_CTRL_RNG_DIV_CTRL_SHIFT) | RNG_CTRL_RNG_RBGEN_MASK;
++ iowrite32(val, priv->base + RNG_CTRL_OFFSET);
++
++ return 0;
++}
++
+ static void iproc_rng200_cleanup(struct hwrng *rng)
+ {
+ struct iproc_rng200_dev *priv = to_rng_priv(rng);
+@@ -202,10 +268,16 @@ static int iproc_rng200_probe(struct pla
+ return PTR_ERR(priv->base);
+ }
+
+- priv->rng.name = "iproc-rng200",
+- priv->rng.read = iproc_rng200_read,
+- priv->rng.init = iproc_rng200_init,
+- priv->rng.cleanup = iproc_rng200_cleanup,
++ priv->rng.name = pdev->name;
++ priv->rng.cleanup = iproc_rng200_cleanup;
++
++ if (of_device_is_compatible(dev->of_node, "brcm,bcm2838-rng200")) {
++ priv->rng.init = bcm2838_rng200_init;
++ priv->rng.read = bcm2838_rng200_read;
++ } else {
++ priv->rng.init = iproc_rng200_init;
++ priv->rng.read = iproc_rng200_read;
++ }
+
+ /* Register driver */
+ ret = devm_hwrng_register(dev, &priv->rng);
+@@ -222,6 +294,7 @@ static int iproc_rng200_probe(struct pla
+ static const struct of_device_id iproc_rng200_of_match[] = {
+ { .compatible = "brcm,bcm7278-rng200", },
+ { .compatible = "brcm,iproc-rng200", },
++ { .compatible = "brcm,bcm2838-rng200"},
+ {},
+ };
+ MODULE_DEVICE_TABLE(of, iproc_rng200_of_match);
projects / openwrt / staging / chunkeey.git / blobdiff