From patchwork Sun Oct 16 16:29:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: tollsimy X-Patchwork-Id: 3071 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:4ac7:0:0:0:0:0 with SMTP id y7csp1080787wrs; Sun, 16 Oct 2022 09:34:02 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6vbtvN45hg7BfWZcTOysWYv8qh1tXOp2rW1/rxT/TE2cL1pf8yeAQ/22qUsxeCSE2C9QeV X-Received: by 2002:a17:90b:2241:b0:20d:b273:26af with SMTP id hk1-20020a17090b224100b0020db27326afmr8733707pjb.245.1665938042234; Sun, 16 Oct 2022 09:34:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1665938042; cv=none; d=google.com; s=arc-20160816; b=nyK9kgPsmkn4m/LAfpELIJ+mBsaCQ+Xq2fMjEO1uRyklpLe8QiTcgdjaWR5coGsJgf 6/69UE1zfqfcZKpoke8hn2NgSZwIdAEok4b9fhGy7r9S0hF2mV//JPk/8E6frOEZyLaC TvvKK6TlWLMqD1AaVd++g/3CMI7VCHCEeH9VHmthSImZYh9TiCK5O2zgsbr/UwsUjf8g elH1I6L4her+7EQ/GohoNILqAjEeJQWFn0H+E5izOnjR1dAcLYviXfomFYHekIoZ1Gn1 KCPz3aeTT/2GaPfiLGFZ6/ItwgHm+QEslLBYjavIIkRzQ+ZgCS7LTKZkRypzZEzi+hZG W7gw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=mpGhma0ux544N/LSculCP7CyWmsp71OY4+BVJajygNs=; b=pNKM0liU9vAStWQvsqFSAkOr0KBR05aNYqE78VRm16WbOUxKZp/OmfRz7fkFHtCl2K b02+a7YNMh2cPpTwiGtsqLK29KNSyd+UNRJKAY2ZLXLrcEDfaQunGb/+LXGhHHeN85+S 89tPDtPW5b3lYjK1HOZZS8C6TV0Wwy9iXE22qZQMlWLyG/hhY/pQjD+S/SpLEmP03mHj obWoVn1UeTr3xLV6f6Jf4i5pSBxFZLNFXac5Mz3W5Scr2Qy5ejBzBdW0jatxGskY4eHK laTCePKSY/mLc9ptIj4dlEHdViFGGJbfvAuG67B4ap3np6J6S4biQOh7uzTq9bRPFBnK 7wnA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=bM+38r1+; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id a3-20020a170902ecc300b0017a0a6b5b11si10409598plh.145.2022.10.16.09.33.47; Sun, 16 Oct 2022 09:34:02 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=bM+38r1+; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229673AbiJPQ32 (ORCPT + 99 others); Sun, 16 Oct 2022 12:29:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229646AbiJPQ3Z (ORCPT ); Sun, 16 Oct 2022 12:29:25 -0400 Received: from mail-ej1-x635.google.com (mail-ej1-x635.google.com [IPv6:2a00:1450:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8931FA; Sun, 16 Oct 2022 09:29:18 -0700 (PDT) Received: by mail-ej1-x635.google.com with SMTP id y14so20092552ejd.9; Sun, 16 Oct 2022 09:29:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=mpGhma0ux544N/LSculCP7CyWmsp71OY4+BVJajygNs=; b=bM+38r1+2BJ08XEH5whOixcOrcvZipu76RP2quEg8G3JMV2LSyzKei4cC0nxHoH0cI PCEQBPB9A6hAFfeGfA2QFzDB0hRoHVXlQANriM0RjghU0B2oQqlmDsAORbV3sA6GoPGI ompg6eCfvGRBLpz82uYmBwjAuYywSnx3T9vQgK6wb5IhkJR3aZoln1fZvEfvQhjwCaGb GBQNagWXxfAfCPuPJ4pEehcdHQsZ/zJaWTAXpUXpYF5HjkmviZx8VLDcUe+afksAfTwR 7NSORFjPLEoGCrXNNF/SmXt/DQS4NjgqxnhW4mL9976kqk/yQrTZBgPsuTjMjYk2Rtw2 tT4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=mpGhma0ux544N/LSculCP7CyWmsp71OY4+BVJajygNs=; b=7tVlhIEmRy38/f9vk28OJekqddZtMZDpqDoGtWwUWvYd9h+ivrV92IwPflY17M6GNC VdgVFamKsCjXy5Pxjy0RCNZD5a0yvr94gw2o5P6eatDyzHWki7bPufMM101BvngvhgeP uShqTuDYaBv489rTq0IKLQ3LJzuu5/DO/pTeRodSTMTHNMfbDEAka4FEdLmdNn7/w2Kc NeDJXQATyFmmmMT5oIBfS6OlQ9we0WvZLbK9Lje19XVx0ftUfIXA2klUwBGy1bo8JZt6 iT12fJ/rzP+vnHS8AR9WpyWJAFmu8AObFeDYAysTPJ9hZ5fPHzQZkZxzKcXXiDEDJCLN LwPQ== X-Gm-Message-State: ACrzQf0MFeiROjp4Inbd1B4pplI4lSuaAqLsmxCp3HDwKNh3VgB6AtBI sVHaogSEBZwgFJpxhnX6Kas= X-Received: by 2002:a17:906:dc8a:b0:788:4d96:1274 with SMTP id cs10-20020a170906dc8a00b007884d961274mr5721699ejc.540.1665937757268; Sun, 16 Oct 2022 09:29:17 -0700 (PDT) Received: from fedora.. ([88.147.86.156]) by smtp.gmail.com with ESMTPSA id h16-20020a170906719000b0078135401b9csm4790142ejk.130.2022.10.16.09.29.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 16 Oct 2022 09:29:16 -0700 (PDT) From: tollsimy To: a.zummo@towertech.it Cc: alexandre.belloni@bootlin.com, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, tollsimy Subject: [PATCH] Microchip MCP795xx RTC driver patch Date: Sun, 16 Oct 2022 18:29:13 +0200 Message-Id: <20221016162913.38661-1-simonetollardo@gmail.com> X-Mailer: git-send-email 2.37.3 MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1746862648368465333?= X-GMAIL-MSGID: =?utf-8?q?1746862648368465333?= RTC Microchip mcp795 patch for 5.19-rc5 Here is the mcp795 patch for the 5.19-rc5 merge window. The main modification are the following: - fixed wrong driver naming: RTC is a Microchip mcp795 and not Maxim mcp795 - added date/time write sequences: added date/time write sequences accordingly to official silicon errata document to fix silicon bugs. - added support to date/time permanent storage: the driver was missing some register bits in order to enable the storage of date/time whenever the device looses main power. - added a check after starting oscillator in order to be sure that it is properly working as specified in the datasheet - renamed OSCON bit to OSCRUN as in the datasheet - add debug messages when setting and reading the alarm - removed wrong offset when retrieving the current year from the device The patch has been successfully tested in the latest linux-next releases, and the original problems that I found have all been resolved. Signed-off-by: tollsimy --- .../devicetree/bindings/rtc/maxim,mcp795.txt | 11 - .../bindings/rtc/microchip,mcp795.txt | 11 + drivers/rtc/rtc-mcp795.c | 359 ++++++++++++++---- 3 files changed, 296 insertions(+), 85 deletions(-) delete mode 100644 Documentation/devicetree/bindings/rtc/maxim,mcp795.txt create mode 100644 Documentation/devicetree/bindings/rtc/microchip,mcp795.txt diff --git a/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt b/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt deleted file mode 100644 index a59fdd8c236d..000000000000 --- a/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt +++ /dev/null @@ -1,11 +0,0 @@ -* Maxim MCP795 SPI Serial Real-Time Clock - -Required properties: -- compatible: Should contain "maxim,mcp795". -- reg: SPI address for chip - -Example: - mcp795: rtc@0 { - compatible = "maxim,mcp795"; - reg = <0>; - }; diff --git a/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt b/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt new file mode 100644 index 000000000000..854364c3a173 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt @@ -0,0 +1,11 @@ +* Microchip MCP795 SPI Serial Real-Time Clock + +Required properties: +- compatible: Should contain "microchip,mcp795". +- reg: SPI address for chip + +Example: + mcp795: rtc@0 { + compatible = "microchip,mcp795"; + reg = <0>; + }; diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c index 0d515b3df571..292a440b62dd 100644 --- a/drivers/rtc/rtc-mcp795.c +++ b/drivers/rtc/rtc-mcp795.c @@ -3,11 +3,15 @@ * SPI Driver for Microchip MCP795 RTC * * Copyright (C) Josef Gajdusek + * Copyright (C) 2022 Simone Tollardo * * based on other Linux RTC drivers * * Device datasheet: - * https://ww1.microchip.com/downloads/en/DeviceDoc/22280A.pdf + * https://ww1.microchip.com/downloads/en/DeviceDoc/MCP7951X-MCP7952X-Battery-Backed-SPI-RTCC-20002300C.pdf + * + * Device errata: + * http://ww1.microchip.com/downloads/en/DeviceDoc/MCP795XX-Family-Silicon-Errata-80000680D.pdf */ #include @@ -32,28 +36,148 @@ #define MCP795_UNLOCK 0x14 #define MCP795_IDWRITE 0x32 #define MCP795_IDREAD 0x33 -#define MCP795_CLRWDT 0x44 #define MCP795_CLRRAM 0x54 /* MCP795 RTCC registers, see datasheet table 4-1 */ +#define MCP795_REG_TMSECONDS 0x00 /* Tenths of ms (=centi-seconds) */ #define MCP795_REG_SECONDS 0x01 +#define MCP795_REG_MINUTES 0x02 +#define MCP795_REG_HOURS 0x03 #define MCP795_REG_DAY 0x04 +#define MCP795_REG_DATE 0x05 #define MCP795_REG_MONTH 0x06 +#define MCP795_REG_YEAR 0x07 #define MCP795_REG_CONTROL 0x08 +#define MCP795_REG_OSC_TRIM 0x09 +/* Alarm 0 */ #define MCP795_REG_ALM0_SECONDS 0x0C +#define MCP795_REG_ALM0_MINUTES 0x0D +#define MCP795_REG_ALM0_HOURS 0x0E #define MCP795_REG_ALM0_DAY 0x0F - -#define MCP795_ST_BIT BIT(7) -#define MCP795_24_BIT BIT(6) -#define MCP795_LP_BIT BIT(5) -#define MCP795_EXTOSC_BIT BIT(3) -#define MCP795_OSCON_BIT BIT(5) -#define MCP795_ALM0_BIT BIT(4) -#define MCP795_ALM1_BIT BIT(5) -#define MCP795_ALM0IF_BIT BIT(3) -#define MCP795_ALM0C0_BIT BIT(4) -#define MCP795_ALM0C1_BIT BIT(5) -#define MCP795_ALM0C2_BIT BIT(6) +#define MCP795_REG_ALM0_DATE 0x10 +#define MCP795_REG_ALM0_MONTH 0x11 /* Month only for alarm 0 */ +/* Alarm 1 */ +#define MCP795_REG_ALM1_TMSECONDS 0x12 /* Centi-seconds only for alarm 1 */ +#define MCP795_REG_ALM1_SECONDS 0x13 +#define MCP795_REG_ALM1_MINUTES 0x14 +#define MCP795_REG_ALM1_HOURS 0x15 +#define MCP795_REG_ALM1_DAY 0x16 +#define MCP795_REG_ALM1_DATE 0x17 + +/* Power-Fail Timestamp */ +/* Power-Down Timetsamp */ +#define MCP795_REG_PWD_MINUTES 0x18 +#define MCP795_REG_PWD_HOURS 0x19 +#define MCP795_REG_PWD_DATE 0x1A +#define MCP795_REG_PWD_MONTH 0x1B +/* Power-Up Timestamp */ +#define MCP795_REG_PUP_MINUTES 0x1C +#define MCP795_REG_PUP_HOURS 0x1D +#define MCP795_REG_PUP_DATE 0x1E +#define MCP795_REG_PUP_MONTH 0x1F + +/* MCP795_REG_CONTROL bits */ + +/* MISC */ +#define MCP795_ST_BIT BIT(7) /* Status bit */ +#define MCP795_24_BIT BIT(6) /* 12/24 hour mode */ +#define MCP795_LP_BIT BIT(5) /* Leap Year */ +#define MCP795_OSCRUN_BIT BIT(5) /* Oscillator Run */ +#define MCP795_PWRFAIL_BIT BIT(4) /* Power Fail */ +#define MCP795_VBATEN_BIT BIT(3) /* VBAT Enable */ + +/* RTCC 0x08 register bits */ +#define MCP795_SQWEN_BIT BIT(6) /* Square Wave Enable (MFP pin) */ +#define MCP795_ALM1_EN_BIT BIT(5) /* Alarm 1 Enable */ +#define MCP795_ALM0_EN_BIT BIT(4) /* Alarm 0 Enable */ +#define MCP795_EXTOSC_BIT BIT(3) /* External Oscillator */ +#define MCP795_CRSTRIM_BIT BIT(2) /* Crystal Trim */ +#define MCP795_SQWFS_BIT_H BIT(1) /* Square Wave Frequency Select H */ +#define MCP795_SQWFS_BIT_L BIT(0) /* Square Wave Frequency Select L */ + +/* Alarms (0 and 1) */ + +/* Centi-seconds - ALARM 1 ONLY */ +/* Alarms BCD Decimal Values of Centi-Second's Tens Digit (=deci-seconds) */ +#define MCP795_ALM1_CSEC_T_C0_BIT BIT(4) +#define MCP795_ALM1_CSEC_T_C1_BIT BIT(5) +#define MCP795_ALM1_CSEC_T_C2_BIT BIT(6) +#define MCP795_ALM1_CSEC_T_C3_BIT BIT(6) +/* Alarms BCD Decimal Values of Centi-Second's Ones Digit (=centi-seconds) */ +#define MCP795_ALM1_CSEC_O_C0_BIT BIT(0) +#define MCP795_ALM1_CSEC_O_C1_BIT BIT(1) +#define MCP795_ALM1_CSEC_O_C2_BIT BIT(2) +#define MCP795_ALM1_CSEC_O_C3_BIT BIT(3) + +/* Seconds */ +/* Alarms BCD Decimal Values of Second's Tens Digit */ +#define MCP795_ALM_SEC_T_C0_BIT BIT(4) +#define MCP795_ALM_SEC_T_C1_BIT BIT(5) +#define MCP795_ALM_SEC_T_C2_BIT BIT(6) +/* Alarms BCD Decimal Values of Second's Ones Digit */ +#define MCP795_ALM_SEC_O_C0_BIT BIT(0) +#define MCP795_ALM_SEC_O_C1_BIT BIT(1) +#define MCP795_ALM_SEC_O_C2_BIT BIT(2) +#define MCP795_ALM_SEC_O_C3_BIT BIT(3) + +/* Minutes */ +/* Alarms BCD Decimal Values of Minute's Tens Digit */ +#define MCP795_ALM_MIN_T_C0_BIT BIT(4) +#define MCP795_ALM_MIN_T_C1_BIT BIT(5) +#define MCP795_ALM_MIN_T_C2_BIT BIT(6) +/* Alarms BCD Decimal Values of Minute's Ones Digit */ +#define MCP795_ALM_MIN_O_C0_BIT BIT(0) +#define MCP795_ALM_MIN_O_C1_BIT BIT(1) +#define MCP795_ALM_MIN_O_C2_BIT BIT(2) +#define MCP795_ALM_MIN_O_C3_BIT BIT(3) + +/* Hours */ +/* Alarms BCD Decimal Values of Hour's Tens Digit */ +#define MCP795_ALM_HOUR_T_C0_BIT BIT(4) +/* Alarms BCD Decimal Values of Hour's Ones Digit */ +#define MCP795_ALM_HOUR_O_C0_BIT BIT(0) +#define MCP795_ALM_HOUR_O_C1_BIT BIT(1) +#define MCP795_ALM_HOUR_O_C2_BIT BIT(2) +#define MCP795_ALM_HOUR_O_C3_BIT BIT(3) + +/* Days */ +/* Alarms Interrupt Flag */ +#define MCP795_ALM_IF_BIT BIT(3) +/* Alarms BCD Decimal Values of Day's Ones Digit */ +#define MCP795_ALM_DAY_O_C0_BIT BIT(0) +#define MCP795_ALM_DAY_O_C1_BIT BIT(1) +#define MCP795_ALM_DAY_O_C2_BIT BIT(2) + +/* Date */ +/* Alarms BCD Decimal Values of Date's Tens Digit */ +#define MCP795_ALM_DATE_T_C0_BIT BIT(4) +#define MCP795_ALM_DATE_T_C1_BIT BIT(5) +/* Alarms BCD Decimal Values of Date's Ones Digit */ +#define MCP795_ALM_DATE_O_C0_BIT BIT(0) +#define MCP795_ALM_DATE_O_C1_BIT BIT(1) +#define MCP795_ALM_DATE_O_C2_BIT BIT(2) +#define MCP795_ALM_DATE_O_C3_BIT BIT(3) + +/* Months */ +/* Alarms BCD Decimal Values of Month's Tens Digit */ +#define MCP795_ALM0_MONTH_T_C0_BIT BIT(3) +/* Alarms BCD Decimal Values of Month's Ones Digit */ +#define MCP795_ALM0_MONTH_O_C0_BIT BIT(0) +#define MCP795_ALM0_MONTH_O_C1_BIT BIT(1) +#define MCP795_ALM0_MONTH_O_C2_BIT BIT(2) +#define MCP795_ALM0_MONTH_O_C3_BIT BIT(3) + +/* Alarms Masks */ +#define MCP795_ALM_MASKS_BIT BIT(4) + +/* BCD mask values for alarm matching - need BCD conversion */ +#define MCP795_ALM_MASK_SEC 0x00 +#define MCP795_ALM_MASK_MIN 0x01 +#define MCP795_ALM_MASK_HOUR 0x02 +#define MCP795_ALM_MASK_DAY 0x03 +#define MCP795_ALM_MASK_DATE 0x04 +#define MCP795_ALM_MASK_CSEC 0x05 +#define MCP795_ALM_MASK_ALL 0x07 #define SEC_PER_DAY (24 * 60 * 60) @@ -69,7 +193,7 @@ static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count) if (ret) dev_err(dev, "Failed reading %d bytes from address %x.\n", - count, addr); + count, addr); return ret; } @@ -88,7 +212,7 @@ static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count) if (ret) dev_err(dev, "Failed to write %d bytes to address %x.\n", - count, addr); + count, addr); return ret; } @@ -123,17 +247,16 @@ static int mcp795_stop_oscillator(struct device *dev, bool *extosc) if (ret) return ret; *extosc = !!(data & MCP795_EXTOSC_BIT); - ret = mcp795_rtcc_set_bits( - dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, 0); + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, 0); if (ret) return ret; - /* wait for the OSCON bit to clear */ + /* wait for the OSCRUN bit to clear */ do { usleep_range(700, 800); ret = mcp795_rtcc_read(dev, MCP795_REG_DAY, &data, 1); if (ret) break; - if (!(data & MCP795_OSCON_BIT)) + if (!(data & MCP795_OSCRUN_BIT)) break; } while (--retries); @@ -143,17 +266,34 @@ static int mcp795_stop_oscillator(struct device *dev, bool *extosc) static int mcp795_start_oscillator(struct device *dev, bool *extosc) { + int ret; + int retries = 5; + if (extosc) { u8 data = *extosc ? MCP795_EXTOSC_BIT : 0; - int ret; - ret = mcp795_rtcc_set_bits( - dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, data); + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, data); if (ret) return ret; } - return mcp795_rtcc_set_bits( - dev, MCP795_REG_SECONDS, MCP795_ST_BIT, MCP795_ST_BIT); + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_SECONDS, MCP795_ST_BIT, MCP795_ST_BIT); + if (ret) + return ret; + + /* wait for the OSCRUN bit to set */ + do { + u8 data = MCP795_OSCRUN_BIT; + + usleep_range(700, 800); + ret = mcp795_rtcc_read(dev, MCP795_REG_DAY, &data, 1); + if (ret) + break; + if ((data & MCP795_OSCRUN_BIT)) + break; + + } while (--retries); + + return !retries ? -EIO : ret; } /* Enable or disable Alarm 0 in RTC */ @@ -164,18 +304,24 @@ static int mcp795_update_alarm(struct device *dev, bool enable) dev_dbg(dev, "%s alarm\n", enable ? "Enable" : "Disable"); if (enable) { + /* Disable Square Wave Function to enable Alarm output */ + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, + MCP795_SQWEN_BIT, 0); /* clear ALM0IF (Alarm 0 Interrupt Flag) bit */ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_ALM0_DAY, - MCP795_ALM0IF_BIT, 0); + MCP795_ALM_IF_BIT, 0); if (ret) return ret; /* enable alarm 0 */ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, - MCP795_ALM0_BIT, MCP795_ALM0_BIT); + MCP795_ALM0_EN_BIT, MCP795_ALM0_EN_BIT); } else { /* disable alarm 0 and alarm 1 */ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, - MCP795_ALM0_BIT | MCP795_ALM1_BIT, 0); + MCP795_ALM0_EN_BIT | MCP795_ALM1_EN_BIT, 0); + /* Disable Alarm output to let enable Square Wave Function */ + ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, + MCP795_SQWEN_BIT, 0); } return ret; } @@ -183,7 +329,7 @@ static int mcp795_update_alarm(struct device *dev, bool enable) static int mcp795_set_time(struct device *dev, struct rtc_time *tim) { int ret; - u8 data[7]; + u8 data[8]; bool extosc; /* Stop RTC and store current value of EXTOSC bit */ @@ -192,32 +338,42 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim) return ret; /* Read first, so we can leave config bits untouched */ - ret = mcp795_rtcc_read(dev, MCP795_REG_SECONDS, data, sizeof(data)); + ret = mcp795_rtcc_read(dev, MCP795_REG_TMSECONDS, data, sizeof(data)); if (ret) return ret; - data[0] = (data[0] & 0x80) | bin2bcd(tim->tm_sec); - data[1] = (data[1] & 0x80) | bin2bcd(tim->tm_min); - data[2] = bin2bcd(tim->tm_hour); - data[3] = (data[3] & 0xF8) | bin2bcd(tim->tm_wday + 1); - data[4] = bin2bcd(tim->tm_mday); - data[5] = (data[5] & MCP795_LP_BIT) | bin2bcd(tim->tm_mon + 1); - - if (tim->tm_year > 100) - tim->tm_year -= 100; - - data[6] = bin2bcd(tim->tm_year); - - /* Always write the date and month using a separate Write command. - * This is a workaround for a know silicon issue that some combinations - * of date and month values may result in the date being reset to 1. - */ - ret = mcp795_rtcc_write(dev, MCP795_REG_SECONDS, data, 5); + data[0] = 0x00; //centiseconds not implemented + data[1] = (data[0] & 0x80) | bin2bcd(tim->tm_sec); + data[2] = (data[1] & 0x80) | bin2bcd(tim->tm_min); + data[3] = (data[3] & 0xC0) | bin2bcd(tim->tm_hour); + /* Add one beacause Linux weekday is from 0 to 6 */ + data[4] = (data[3] & 0xF8) | bin2bcd(tim->tm_wday + 1); + data[5] = (data[5] & 0xC0) | bin2bcd(tim->tm_mday); + /* Add one because Linux month is from 0 to 11 */ + data[6] = (data[6] & 0xC0) | ((data[6] & MCP795_LP_BIT) + | bin2bcd(tim->tm_mon + 1)); + data[7] = bin2bcd(tim->tm_year); + + /* Set time sequence needed to avoid common device problems, see errata */ + /* Write month */ + ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[6], 1); if (ret) return ret; - - ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[5], 2); + /* Write data (month day) */ + ret = mcp795_rtcc_write(dev, MCP795_REG_DATE, &data[5], 1); + if (ret) + return ret; + /* Write month again */ + ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[6], 1); + if (ret) + return ret; + /* Send the rest apart from year and dayweek */ + ret = mcp795_rtcc_write(dev, MCP795_REG_TMSECONDS, data, 4); + if (ret) + return ret; + /* Send the year */ + ret = mcp795_rtcc_write(dev, MCP795_REG_YEAR, &data[7], 1); if (ret) return ret; @@ -229,6 +385,14 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim) if (ret) return ret; + /* Always set the weekday using a separate Write command and when + * oscillator is running. + * This is a workaround for a know silicon issue. + */ + ret = mcp795_rtcc_write(dev, MCP795_REG_DAY, &data[4], 1); + if (ret) + return ret; + dev_dbg(dev, "Set mcp795: %ptR\n", tim); return 0; @@ -237,20 +401,23 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim) static int mcp795_read_time(struct device *dev, struct rtc_time *tim) { int ret; - u8 data[7]; + u8 data[8]; + int tm_c_sec; - ret = mcp795_rtcc_read(dev, MCP795_REG_SECONDS, data, sizeof(data)); + ret = mcp795_rtcc_read(dev, MCP795_REG_TMSECONDS, data, sizeof(data)); if (ret) return ret; - tim->tm_sec = bcd2bin(data[0] & 0x7F); - tim->tm_min = bcd2bin(data[1] & 0x7F); - tim->tm_hour = bcd2bin(data[2] & 0x3F); - tim->tm_wday = bcd2bin(data[3] & 0x07) - 1; - tim->tm_mday = bcd2bin(data[4] & 0x3F); - tim->tm_mon = bcd2bin(data[5] & 0x1F) - 1; - tim->tm_year = bcd2bin(data[6]) + 100; /* Assume we are in 20xx */ + tm_c_sec = bcd2bin(data[0] & 0xFF); + tim->tm_sec = bcd2bin(data[1] & 0x7F); + tim->tm_min = bcd2bin(data[2] & 0x7F); + /* This is only for 24h mode, see datasheet for 12h mode */ + tim->tm_hour = bcd2bin(data[3] & 0x3F); + tim->tm_wday = bcd2bin(data[4] & 0x07) - 1; + tim->tm_mday = bcd2bin(data[5] & 0x3F); + tim->tm_mon = bcd2bin(data[6] & 0x1F) - 1; + tim->tm_year = bcd2bin(data[7]); dev_dbg(dev, "Read from mcp795: %ptR\n", tim); @@ -265,6 +432,17 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm) u8 tmp[6]; int ret; + /* Set Alarm 0 Mask to match all */ + /* Read first, so we can leave other bits untouched */ + ret = mcp795_rtcc_read(dev, MCP795_REG_ALM0_DAY, tmp, 1); + if (ret) + return ret; + /* Set Alarm 0 Mask to match all */ + tmp[0] = (tmp[0] & 0x8F) | (bin2bcd(MCP795_ALM_MASK_ALL) << 4); + ret = mcp795_rtcc_write(dev, MCP795_REG_ALM0_DAY, tmp, 1); + if (ret) + return ret; + /* Read current time from RTC hardware */ ret = mcp795_read_time(dev, &now_tm); if (ret) @@ -291,12 +469,14 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm) alm->time.tm_isdst = -1; alm->time.tm_yday = -1; + /* set alarm match: seconds, minutes, hour, day, date and month */ tmp[0] = (tmp[0] & 0x80) | bin2bcd(alm->time.tm_sec); tmp[1] = (tmp[1] & 0x80) | bin2bcd(alm->time.tm_min); tmp[2] = (tmp[2] & 0xE0) | bin2bcd(alm->time.tm_hour); tmp[3] = (tmp[3] & 0x80) | bin2bcd(alm->time.tm_wday + 1); - /* set alarm match: seconds, minutes, hour, day, date and month */ - tmp[3] |= (MCP795_ALM0C2_BIT | MCP795_ALM0C1_BIT | MCP795_ALM0C0_BIT); + /* ALMxIF cleared in the update function */ + tmp[3] |= (MCP795_ALM_SEC_T_C2_BIT | MCP795_ALM_SEC_T_C1_BIT + | MCP795_ALM_SEC_T_C0_BIT); tmp[4] = (tmp[4] & 0xC0) | bin2bcd(alm->time.tm_mday); tmp[5] = (tmp[5] & 0xE0) | bin2bcd(alm->time.tm_mon + 1); @@ -309,10 +489,14 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm) ret = mcp795_update_alarm(dev, true); if (ret) return ret; + alm->pending = 1; dev_dbg(dev, "Alarm IRQ armed\n"); } - dev_dbg(dev, "Set alarm: %ptRdr(%d) %ptRt\n", - &alm->time, alm->time.tm_wday, &alm->time); + + /* do not print year, it's not implemented in the RTC hardware */ + dev_dbg(dev, "Set alarm: %02d-%02dT%02d:%02d:%02d\n", alm->time.tm_mon + 1, + alm->time.tm_mday, alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec); + return 0; } @@ -321,8 +505,7 @@ static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm) u8 data[6]; int ret; - ret = mcp795_rtcc_read( - dev, MCP795_REG_ALM0_SECONDS, data, sizeof(data)); + ret = mcp795_rtcc_read(dev, MCP795_REG_ALM0_SECONDS, data, sizeof(data)); if (ret) return ret; @@ -336,8 +519,17 @@ static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm) alm->time.tm_isdst = -1; alm->time.tm_yday = -1; - dev_dbg(dev, "Read alarm: %ptRdr(%d) %ptRt\n", - &alm->time, alm->time.tm_wday, &alm->time); + alm->pending = !!(data[3] & MCP795_ALM_IF_BIT); + + ret = mcp795_rtcc_read(dev, MCP795_REG_CONTROL, data, 1); + if (ret) + return ret; + alm->enabled = !!(data[0] & MCP795_ALM0_EN_BIT); + + /* Do not print year, it's not implemented in the RTC hardware */ + dev_dbg(dev, "Read alarm: %02d-%02dT%02d:%02d:%02d\n", alm->time.tm_mon + 1, + alm->time.tm_mday, alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec); + return 0; } @@ -381,6 +573,7 @@ static int mcp795_probe(struct spi_device *spi) { struct rtc_device *rtc; int ret; + u8 data; spi->mode = SPI_MODE_0; spi->bits_per_word = 8; @@ -393,10 +586,10 @@ static int mcp795_probe(struct spi_device *spi) /* Start the oscillator but don't set the value of EXTOSC bit */ mcp795_start_oscillator(&spi->dev, NULL); /* Clear the 12 hour mode flag*/ - mcp795_rtcc_set_bits(&spi->dev, 0x03, MCP795_24_BIT, 0); + mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_HOURS, MCP795_24_BIT, 0); rtc = devm_rtc_device_register(&spi->dev, "rtc-mcp795", - &mcp795_rtc_ops, THIS_MODULE); + &mcp795_rtc_ops, THIS_MODULE); if (IS_ERR(rtc)) return PTR_ERR(rtc); @@ -409,22 +602,40 @@ static int mcp795_probe(struct spi_device *spi) * the interrupt. */ mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_ALM0_DAY, - MCP795_ALM0IF_BIT, 0); - ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, - mcp795_irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, - dev_name(&rtc->dev), spi); + MCP795_ALM_IF_BIT, 0); + ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, mcp795_irq, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + dev_name(&rtc->dev), spi); if (ret) dev_err(&spi->dev, "Failed to request IRQ: %d: %d\n", - spi->irq, ret); + spi->irq, ret); else device_init_wakeup(&spi->dev, true); } + + /* If PWRFAIL BIT is set, it must be cleared */ + ret = mcp795_rtcc_read(&spi->dev, MCP795_REG_DAY, &data, 1); + if (ret) + return ret; + + if (!!(data & MCP795_PWRFAIL_BIT)) { + ret = mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_DAY, + MCP795_PWRFAIL_BIT, 0); + if (ret) + return ret; + } + /* Set VBAT flag to 1 */ + ret = mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_DAY, MCP795_VBATEN_BIT, + MCP795_VBATEN_BIT); + if (ret) + return ret; + return 0; } #ifdef CONFIG_OF static const struct of_device_id mcp795_of_match[] = { - { .compatible = "maxim,mcp795" }, + { .compatible = "microchip,mcp795" }, { } }; MODULE_DEVICE_TABLE(of, mcp795_of_match);