From: Rick Altherr Subject: [PATCH v2 2/2] hw_random: timeriomem_rng: Allow setting RNG quality from platform data Date: Mon, 22 May 2017 14:12:24 -0700 Message-ID: <20170522211224.12202-2-raltherr@google.com> References: <20170522211224.12202-1-raltherr@google.com> Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Herbert Xu , Matt Mackall To: linux-crypto@vger.kernel.org Return-path: Received: from mail-pf0-f180.google.com ([209.85.192.180]:34242 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935792AbdEVVM3 (ORCPT ); Mon, 22 May 2017 17:12:29 -0400 Received: by mail-pf0-f180.google.com with SMTP id 9so93435190pfj.1 for ; Mon, 22 May 2017 14:12:29 -0700 (PDT) In-Reply-To: <20170522211224.12202-1-raltherr@google.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: When a hw_random device's quality is non-zero, it will automatically be used to fill the kernel's entropy pool. Since timeriomem_rng is used by many different devices, the quality needs to be provided by platform data or device tree. Signed-off-by: Rick Altherr --- Changes in v2: - Adjust header comment for platform data quality property to match code and DT bindings drivers/char/hw_random/timeriomem-rng.c | 7 +++++++ include/linux/timeriomem-rng.h | 3 +++ 2 files changed, 10 insertions(+) diff --git a/drivers/char/hw_random/timeriomem-rng.c b/drivers/char/hw_random/timeriomem-rng.c index a0faa5f05deb..03ff5483d865 100644 --- a/drivers/char/hw_random/timeriomem-rng.c +++ b/drivers/char/hw_random/timeriomem-rng.c @@ -151,8 +151,15 @@ static int timeriomem_rng_probe(struct platform_device *pdev) dev_err(&pdev->dev, "missing period\n"); return -EINVAL; } + + if (!of_property_read_u32(pdev->dev.of_node, + "quality", &i)) + priv->rng_ops.quality = i; + else + priv->rng_ops.quality = 0; } else { period = pdata->period; + priv->rng_ops.quality = pdata->quality; } priv->period = ns_to_ktime(period * NSEC_PER_USEC); diff --git a/include/linux/timeriomem-rng.h b/include/linux/timeriomem-rng.h index 46eb27ddbfab..3e00122bcf88 100644 --- a/include/linux/timeriomem-rng.h +++ b/include/linux/timeriomem-rng.h @@ -13,4 +13,7 @@ struct timeriomem_rng_data { /* measures in usecs */ unsigned int period; + + /* bits of entropy per 1024 bits read */ + unsigned int quality; }; -- 2.13.0.303.g4ebf302169-goog