From patchwork Mon Feb 21 07:59:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 544510 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9787C433F5 for ; Mon, 21 Feb 2022 07:58:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346619AbiBUH6v (ORCPT ); Mon, 21 Feb 2022 02:58:51 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346646AbiBUH6s (ORCPT ); Mon, 21 Feb 2022 02:58:48 -0500 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD1262182B; Sun, 20 Feb 2022 23:58:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1645430305; x=1676966305; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=bqtRma4i+aDRPSPwCrS3g3crpowmv6qvyEHjsN3/F0U=; b=t7kIxk8UyyEDmS2+H1u/S+SSLGjurHYFKn7CPX8eYCkyHzQQx3sT5hFq h4ZmJHSoQhMkSqwdfcEuycLpTTcLDp80OS/4DkevypJiN0EsMFGh64/ak i7dHgF7JapodbIuuzGGJDDNBiISMV6e2JfoaoPbgjxiXOa/os3XxwbjA6 vNY1Sxs6pmlsKW0p+gYxZXghWzkr6nsodUrKAR2zd3NuKma2cCN0lLg3l Gy8xrwq0v1NMrXmlhBJT5HK6e/dOAf8w8o7qkIf7Lh+63lRBfQJDH9V4R /zCZWKMfQH9jr6SFAi6Z/Cj23+lYXTQnw2uq6yCgvOZvDJe/tMk/gjryU Q==; X-IronPort-AV: E=Sophos;i="5.88,385,1635231600"; d="scan'208";a="86422606" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 21 Feb 2022 00:58:24 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Mon, 21 Feb 2022 00:58:24 -0700 Received: from localhost.localdomain (10.10.115.15) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server id 15.1.2375.17 via Frontend Transport; Mon, 21 Feb 2022 00:58:22 -0700 From: Claudiu Beznea To: , , , CC: , , , Claudiu Beznea Subject: [PATCH v2 1/7] hwrng: atmel - add wait for ready support on read Date: Mon, 21 Feb 2022 09:59:22 +0200 Message-ID: <20220221075928.563806-2-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220221075928.563806-1-claudiu.beznea@microchip.com> References: <20220221075928.563806-1-claudiu.beznea@microchip.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add wait for ready support on read. Signed-off-by: Claudiu Beznea --- drivers/char/hw_random/atmel-rng.c | 43 +++++++++++++++++++++--------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index ecb71c4317a5..1a4874668c04 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -20,6 +21,7 @@ #define TRNG_CR 0x00 #define TRNG_MR 0x04 #define TRNG_ISR 0x1c +#define TRNG_ISR_DATRDY BIT(0) #define TRNG_ODATA 0x50 #define TRNG_KEY 0x524e4700 /* RNG */ @@ -36,25 +38,40 @@ struct atmel_trng { struct hwrng rng; }; +static bool atmel_trng_wait_ready(struct atmel_trng *trng, bool wait) +{ + int ready; + + ready = readl(trng->base + TRNG_ISR) & TRNG_ISR_DATRDY; + if (!ready && wait) + readl_poll_timeout(trng->base + TRNG_ISR, ready, + ready & TRNG_ISR_DATRDY, 1000, 20000); + + return !!ready; +} + static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { struct atmel_trng *trng = container_of(rng, struct atmel_trng, rng); u32 *data = buf; + int ret; + + ret = atmel_trng_wait_ready(trng, wait); + if (!ret) + goto out; - /* data ready? */ - if (readl(trng->base + TRNG_ISR) & 1) { - *data = readl(trng->base + TRNG_ODATA); - /* - ensure data ready is only set again AFTER the next data - word is ready in case it got set between checking ISR - and reading ODATA, so we don't risk re-reading the - same word - */ - readl(trng->base + TRNG_ISR); - return 4; - } else - return 0; + *data = readl(trng->base + TRNG_ODATA); + /* + * ensure data ready is only set again AFTER the next data word is ready + * in case it got set between checking ISR and reading ODATA, so we + * don't risk re-reading the same word + */ + readl(trng->base + TRNG_ISR); + ret = 4; + +out: + return ret; } static void atmel_trng_enable(struct atmel_trng *trng)