From patchwork Sun Nov 29 18:44:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 11939293 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AADB5C3E8C5 for ; Sun, 29 Nov 2020 18:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56F5E20691 for ; Sun, 29 Nov 2020 18:48:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2uXCvQvc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725830AbgK2Srp (ORCPT ); Sun, 29 Nov 2020 13:47:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:36758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725468AbgK2Srp (ORCPT ); Sun, 29 Nov 2020 13:47:45 -0500 Received: from localhost.localdomain (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9650E20691; Sun, 29 Nov 2020 18:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606675624; bh=9CSSHZvnhjk9dOhPZ4fEUVcqkxHWKSOEquLowULXL3g=; h=From:To:Cc:Subject:Date:From; b=2uXCvQvcjnQAhWXkeUo1u1yX82yE2SGnW+/RxOK4g16W7WLzVAQsq3QNn6/b4uZM4 amQFxHBu60GUbOMt6QoA7EY7lJ3EVD90nAyY6e0ED19KLh/RQM0EH3P400fil6Y50X gOxfor/M7+9gfNnMSHXNJKtVM6Z38trEFBPL/6EA= From: Jonathan Cameron To: linux-iio@vger.kernel.org Cc: Jonathan Cameron , Andy Shevchenko , Linus Walleij Subject: [PATCH v2] iio:gyro:mpu3050 Treat otp value as a __le64 and use FIELD_GET() to break up Date: Sun, 29 Nov 2020 18:44:59 +0000 Message-Id: <20201129184459.647538-1-jic23@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Jonathan Cameron Inspired by Andy Shevchenko's proposal to use get_unaligned_leXX(). The whole one time programable memory is treated as a single 64bit little endian value. Thus we can avoid a lot of messy handling of fields overlapping byte boundaries by just loading and manipulating it as an __le64 converted to a u64. That lets us just use FIELD_GET() and GENMASK() to extract the values desired. Note only build tested. We need to use GENMASK_ULL and %llX formatters to account for the larger types used in computing the various fields. Signed-off-by: Jonathan Cameron Cc: Andy Shevchenko Cc: Linus Walleij Link: https://lore.kernel.org/r/20201128185156.428327-1-jic23@kernel.org Tested-by: Linus Walleij Reviewed-by: Linus Walleij Reviewed-by: Andy Shevchenko --- Changes since v1: * Fix 32 bit builds by using GENMASK_ULL (thanks to Linus + Andy) drivers/iio/gyro/mpu3050-core.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c index 00e58060968c..dfa31a23500f 100644 --- a/drivers/iio/gyro/mpu3050-core.c +++ b/drivers/iio/gyro/mpu3050-core.c @@ -13,6 +13,7 @@ * TODO: add support for setting up the low pass 3dB frequency. */ +#include #include #include #include @@ -784,7 +785,8 @@ static int mpu3050_read_mem(struct mpu3050 *mpu3050, static int mpu3050_hw_init(struct mpu3050 *mpu3050) { int ret; - u8 otp[8]; + __le64 otp_le; + u64 otp; /* Reset */ ret = regmap_update_bits(mpu3050->map, @@ -815,29 +817,31 @@ static int mpu3050_hw_init(struct mpu3050 *mpu3050) MPU3050_MEM_USER_BANK | MPU3050_MEM_OTP_BANK_0), 0, - sizeof(otp), - otp); + sizeof(otp_le), + (u8 *)&otp_le); if (ret) return ret; /* This is device-unique data so it goes into the entropy pool */ - add_device_randomness(otp, sizeof(otp)); + add_device_randomness(&otp_le, sizeof(otp_le)); + + otp = le64_to_cpu(otp_le); dev_info(mpu3050->dev, - "die ID: %04X, wafer ID: %02X, A lot ID: %04X, " - "W lot ID: %03X, WP ID: %01X, rev ID: %02X\n", + "die ID: %04llX, wafer ID: %02llX, A lot ID: %04llX, " + "W lot ID: %03llX, WP ID: %01llX, rev ID: %02llX\n", /* Die ID, bits 0-12 */ - (otp[1] << 8 | otp[0]) & 0x1fff, + FIELD_GET(GENMASK_ULL(12, 0), otp), /* Wafer ID, bits 13-17 */ - ((otp[2] << 8 | otp[1]) & 0x03e0) >> 5, + FIELD_GET(GENMASK_ULL(17, 13), otp), /* A lot ID, bits 18-33 */ - ((otp[4] << 16 | otp[3] << 8 | otp[2]) & 0x3fffc) >> 2, + FIELD_GET(GENMASK_ULL(33, 18), otp), /* W lot ID, bits 34-45 */ - ((otp[5] << 8 | otp[4]) & 0x3ffc) >> 2, + FIELD_GET(GENMASK_ULL(45, 34), otp), /* WP ID, bits 47-49 */ - ((otp[6] << 8 | otp[5]) & 0x0380) >> 7, + FIELD_GET(GENMASK_ULL(49, 47), otp), /* rev ID, bits 50-55 */ - otp[6] >> 2); + FIELD_GET(GENMASK_ULL(55, 50), otp)); return 0; }