target/linux/bmips/patches-5.10/054-hwrng-bcm2835-add-reset-support.patch

   1 From e5f9f41d5e62004c913bfd4ddf06abe032f5ce1c Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?=C3=81lvaro=20Fern=C3=A1ndez=20Rojas?= <noltari@gmail.com>
   3 Date: Fri, 5 Mar 2021 08:01:32 +0100
   4 Subject: [PATCH 3/3] hwrng: bcm2835 - add reset support
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 BCM6368 devices need to reset the IPSEC controller in order to generate true
  10 random numbers.
  11
  12 This is what BCM6368 produces without a reset:
  13 root@OpenWrt:/# cat /dev/hwrng | rngtest -c 1000
  14 rngtest 6.10
  15 Copyright (c) 2004 by Henrique de Moraes Holschuh
  16 This is free software; see the source for copying conditions.  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  17
  18 rngtest: starting FIPS tests...
  19 rngtest: bits received from input: 20000032
  20 rngtest: FIPS 140-2 successes: 0
  21 rngtest: FIPS 140-2 failures: 1000
  22 rngtest: FIPS 140-2(2001-10-10) Monobit: 2
  23 rngtest: FIPS 140-2(2001-10-10) Poker: 1000
  24 rngtest: FIPS 140-2(2001-10-10) Runs: 1000
  25 rngtest: FIPS 140-2(2001-10-10) Long run: 30
  26 rngtest: FIPS 140-2(2001-10-10) Continuous run: 0
  27 rngtest: input channel speed: (min=37.253; avg=320.827; max=635.783)Mibits/s
  28 rngtest: FIPS tests speed: (min=12.141; avg=15.034; max=16.428)Mibits/s
  29 rngtest: Program run time: 1336176 microseconds
  30
  31 Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
  32 Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
  33 Acked-by: Florian Fainelli <f.fainelli@gmail.com>
  34 Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
  35 ---
  36  drivers/char/hw_random/bcm2835-rng.c | 10 ++++++++++
  37  1 file changed, 10 insertions(+)
  38
  39 --- a/drivers/char/hw_random/bcm2835-rng.c
  40 +++ b/drivers/char/hw_random/bcm2835-rng.c
  41 @@ -13,6 +13,7 @@
  42  #include <linux/platform_device.h>
  43  #include <linux/printk.h>
  44  #include <linux/clk.h>
  45 +#include <linux/reset.h>
  46
  47  #define RNG_CTRL       0x0
  48  #define RNG_STATUS     0x4
  49 @@ -32,6 +33,7 @@ struct bcm2835_rng_priv {
  50         void __iomem *base;
  51         bool mask_interrupts;
  52         struct clk *clk;
  53 +       struct reset_control *reset;
  54  };
  55
  56  static inline struct bcm2835_rng_priv *to_rng_priv(struct hwrng *rng)
  57 @@ -94,6 +96,10 @@ static int bcm2835_rng_init(struct hwrng
  58                         return ret;
  59         }
  60
  61 +       ret = reset_control_reset(priv->reset);
  62 +       if (ret)
  63 +               return ret;
  64 +
  65         if (priv->mask_interrupts) {
  66                 /* mask the interrupt */
  67                 val = rng_readl(priv, RNG_INT_MASK);
  68 @@ -159,6 +165,10 @@ static int bcm2835_rng_probe(struct plat
  69         if (PTR_ERR(priv->clk) == -EPROBE_DEFER)
  70                 return -EPROBE_DEFER;
  71
  72 +       priv->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
  73 +       if (IS_ERR(priv->reset))
  74 +               return PTR_ERR(priv->reset);
  75 +
  76         priv->rng.name = pdev->name;
  77         priv->rng.init = bcm2835_rng_init;
  78         priv->rng.read = bcm2835_rng_read;