From patchwork Tue May 10 09:44:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 12844739 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3626FC433EF for ; Tue, 10 May 2022 09:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=12aCFTqZgi5ihKF5z7mSy1Ea3Gg7dY1N+K3P7lwoCuk=; b=l6/tOFWWYTGB0e S0XGyX0bHya1JTq6SHTQGkvvt1uRDLPVFPn+p6u8XdF6N14Vu3a1TxQHSMIzRdTyrvvNizzHtFprY qMh/tXZ4Ac6JHrd9p9ftFKXUt+KGr1BbZXv/dklDC8K189ZVFgPE36HwcV3Wc0R5gxyRsfyqVOIiw U0VUacAmnLbrWPByZ72dIQBz8Rb4O9us88i+ojsVmR2ZJGeFcC0y4m7pLfazFK75f7ZBmbmKNrg66 8rojmLOjeJdQjeoLitYrW30R8mSjKdkQX2vLODfp1s3ruKRuBT+2vxlOGZ4cXQVDCyBogeBRjn9gQ +XQZjj6vsabRCzZ4C8eA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1noMOs-000v6s-Fo; Tue, 10 May 2022 09:43:26 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1noMO8-000uoA-Do for linux-arm-kernel@lists.infradead.org; Tue, 10 May 2022 09:42:43 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1652175760; x=1683711760; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=N1UY2lJOSZCEdX0it7pW1fnpV7O7kbLRhnZYTAMVwNE=; b=YKyQGZDCzToJJdWjSDA1xjFXDswDtYG2oxZ2YzgyAYzty4ooJB7iNLIx LAxPQeQbKdsFA+4PY65twIOmIqN+23qAmo7Fy7NsPk24JwPU1IOBZczNJ 2HMZbIXA6nqjAMj9+teKBVpsIM453M+ixp6b/b0nUv25qjyE/2wbWH5XB FYBSWP6XpoH59Ifet6w1tIObJA4SOEwDOqhW5h+rj7dgFFPuTOl34AvYv Zn7HZuBZO94UHHqqY5RdpUxzk7ETgBZ8DrqL1kUYgkhMfsae6RQtlyT0x SKgXpkd+jcxnOMPPFrjACVEREkHItHnXYPh5jLtL9PIKx9DIZAK0pjjG/ w==; X-IronPort-AV: E=Sophos;i="5.91,214,1647327600"; d="scan'208";a="155418765" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 10 May 2022 02:42:36 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.85.144) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Tue, 10 May 2022 02:42:36 -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; Tue, 10 May 2022 02:42:34 -0700 From: Claudiu Beznea To: , , CC: , , , Claudiu Beznea Subject: [PATCH 1/2] dt-bindings: microchip-otpc: document Microchip OTPC Date: Tue, 10 May 2022 12:44:56 +0300 Message-ID: <20220510094457.4070764-2-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220510094457.4070764-1-claudiu.beznea@microchip.com> References: <20220510094457.4070764-1-claudiu.beznea@microchip.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220510_024240_601421_E81BB3F5 X-CRM114-Status: GOOD ( 13.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Document Microchip OTP controller. Signed-off-by: Claudiu Beznea --- .../bindings/nvmem/microchip-otpc.yaml | 55 +++++++++++++++++++ include/dt-bindings/nvmem/microchip,otpc.h | 18 ++++++ 2 files changed, 73 insertions(+) create mode 100644 Documentation/devicetree/bindings/nvmem/microchip-otpc.yaml create mode 040000 include/dt-bindings/nvmem create mode 100644 include/dt-bindings/nvmem/microchip,otpc.h diff --git a/Documentation/devicetree/bindings/nvmem/microchip-otpc.yaml b/Documentation/devicetree/bindings/nvmem/microchip-otpc.yaml new file mode 100644 index 000000000000..a8df7fee5c2b --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/microchip-otpc.yaml @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/nvmem/microchip-otpc.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Microchip SAMA7G5 OTP Controller (OTPC) device tree bindings + +maintainers: + - Claudiu Beznea + +description: | + This binding represents the OTP controller found on SAMA7G5 SoC. + +allOf: + - $ref: "nvmem.yaml#" + +properties: + compatible: + items: + - const: microchip,sama7g5-otpc + - const: syscon + + reg: + maxItems: 1 + + "#address-cells": + const: 1 + + "#size-cells": + const: 1 + +required: + - compatible + - reg + +unevaluatedProperties: false + +examples: + - | + #include + #include + + otpc: efuse@e8c00000 { + compatible = "microchip,sama7g5-otpc", "syscon"; + reg = <0xe8c00000 0xec>; + #address-cells = <1>; + #size-cells = <1>; + + temperature_calib: calib@1 { + reg = ; + }; + }; + +... diff --git a/include/dt-bindings/nvmem/microchip,otpc.h b/include/dt-bindings/nvmem/microchip,otpc.h new file mode 100644 index 000000000000..44b6ed3b8f18 --- /dev/null +++ b/include/dt-bindings/nvmem/microchip,otpc.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _DT_BINDINGS_NVMEM_MICROCHIP_OTPC_H +#define _DT_BINDINGS_NVMEM_MICROCHIP_OTPC_H + +/* + * Need to have it as a multiple of 4 as NVMEM memory is registered with + * stride = 4. + */ +#define OTP_PKT(id) ((id) * 4) + +/* + * Temperature calibration packet length for SAMA7G5: 1 words header, + * 18 words payload. + */ +#define OTP_PKT_SAMA7G5_TEMP_CALIB_LEN (19 * 4) + +#endif From patchwork Tue May 10 09:44:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 12844737 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 082D2C433F5 for ; Tue, 10 May 2022 09:44:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=YbOOD/ZmFAmDkK9j6ynmUXerKIJvrwI16vs7F5KfpJs=; b=scTRwRyWdYNfnt qojj2WhkUbBvJEWaINXi/2opIFPTcFX8IgjLueT4NkVYdULC8ascVbsYPZQeFLT842MspdSwdR5zp 8LPKaXOIG9GTpbYI09qe8Q2X55Q7c7f/X36K+8pauGzWlgGa56lBww7+D6+VRGQVH7mGonc8G5h5r 2thKFxGdq+33kC2J2mSWASVeZc0BRwoZtfxhPZFQojstQs+8f2YE9yZaZV8Nvwuygl34XT2a9Gw85 TAgFAGZfFMZQ1jOA7soZMueEAseNo9fG7r0hrvODz14r+Pj9VkkjY2fBKkmFaA4D+lFufvD6RJ488 79KD42lRxQebTlbsCZ/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1noMOE-000uqt-6r; Tue, 10 May 2022 09:42:46 +0000 Received: from esa.microchip.iphmx.com ([68.232.154.123]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1noMO8-000uoN-5Z for linux-arm-kernel@lists.infradead.org; Tue, 10 May 2022 09:42:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1652175760; x=1683711760; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=NuZ+ce14yWDCUZnk+5vM9M6pcF0vrXF4CGc7D2BC69A=; b=TX6IFQ1LveDEqTAn0LicanXyq7v4GaFN8YUzeGd3xhY1OpuaHsA9lzNw r1TeveuWE3iLUkQSUt4g3++WEJXm3EQNBDSxyet20M3MwvmIaRADp3iZ4 LjHiK/C6EpVQqEJwImNj5JRTBtc+HxvDXED+Kt5qIZCCSEcCs780gfVRW f9Y5fDQqCLYhQ1bv57OF9GEZiDoszuqq/MYdhnl8xbywY+WZEC+CskeLZ SRkGmDN1bkehUYwFN6h2+zRTaA9zGcxhpfg30qdn0VJgc1n7U0cGB2O0y yWsgT3VOO1LKBXQZTj2wyb/ylwDsK7GS4aIHVWrV0hz5+DCPJs8FdGrUk g==; X-IronPort-AV: E=Sophos;i="5.91,214,1647327600"; d="scan'208";a="155418771" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa4.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 10 May 2022 02:42:38 -0700 Received: from chn-vm-ex02.mchp-main.com (10.10.87.72) by chn-vm-ex02.mchp-main.com (10.10.87.72) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Tue, 10 May 2022 02:42:38 -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; Tue, 10 May 2022 02:42:36 -0700 From: Claudiu Beznea To: , , CC: , , , Claudiu Beznea Subject: [PATCH 2/2] nvmem: microchip-otpc: add support Date: Tue, 10 May 2022 12:44:57 +0300 Message-ID: <20220510094457.4070764-3-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20220510094457.4070764-1-claudiu.beznea@microchip.com> References: <20220510094457.4070764-1-claudiu.beznea@microchip.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220510_024240_416594_AC8D91F8 X-CRM114-Status: GOOD ( 35.11 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add support for Microchip OTP controller available on SAMA7G5. The OTPC controls the access to a non-volatile memory. The memory behind OTPC is organized into packets, packets are composed by a fixed length header (4 bytes long) and a variable length payload (payload length is available in the header). When software request the data at an offset in memory the OTPC will return (via header + data registers) the whole packet that has a word at that offset. For a packet in OTP memory like below: offset OTP Memory layout . . . ... . . . 0x0E +-----------+ <--- packet X | header X | 0x12 +-----------+ | payload X | 0x16 | | | | 0x1A | | +-----------+ . . . ... . . . if user requests data at address 0x16 the data started at 0x0E will be returned by controller. User will be able to fetch the whole packet starting at 0x0E (or parts of the packet) via proper registers. The same packet will be returned if software request the data at offset 0x0E or 0x12 or 0x1A. The OTP will be populated by Microchip with at least 2 packets first one being boot configuration packet and the 2nd one being temperature calibration packet. The packet order will be preserved b/w different chip revisions but the packet sizes may change. For the above reasons and to keep the same software able to work on all chip variants the read function of the driver is working with a packet id instead of an offset in OTP memory. Signed-off-by: Claudiu Beznea --- MAINTAINERS | 8 + drivers/nvmem/Kconfig | 7 + drivers/nvmem/Makefile | 2 + drivers/nvmem/microchip-otpc.c | 288 +++++++++++++++++++++++++++++++++ 4 files changed, 305 insertions(+) create mode 100644 drivers/nvmem/microchip-otpc.c diff --git a/MAINTAINERS b/MAINTAINERS index 1bf57fd937b5..f4b646a801ff 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12953,6 +12953,14 @@ S: Supported F: Documentation/devicetree/bindings/mtd/atmel-nand.txt F: drivers/mtd/nand/raw/atmel/* +MICROCHIP OTPC DRIVER +M: Claudiu Beznea +L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) +S: Supported +F: Documentation/devicetree/bindings/nvmem/microchip-otpc.yaml +F: drivers/nvmem/microchip-otpc.c +F: dt-bindings/nvmem/microchip,otpc.h + MICROCHIP PWM DRIVER M: Claudiu Beznea L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index 967d0084800e..d72d879a6d34 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -107,6 +107,13 @@ config MTK_EFUSE This driver can also be built as a module. If so, the module will be called efuse-mtk. +config MICROCHIP_OTPC + tristate "Microchip OTPC support" + depends on ARCH_AT91 || COMPILE_TEST + help + This driver enable the OTP controller available on Microchip SAMA7G5 + SoCs. It controlls the access to the OTP memory connected to it. + config NVMEM_NINTENDO_OTP tristate "Nintendo Wii and Wii U OTP Support" depends on WII || COMPILE_TEST diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index 00e136a0a123..c710b64f9fe4 100644 --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -67,3 +67,5 @@ obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP) += nvmem_sunplus_ocotp.o nvmem_sunplus_ocotp-y := sunplus-ocotp.o obj-$(CONFIG_NVMEM_APPLE_EFUSES) += nvmem-apple-efuses.o nvmem-apple-efuses-y := apple-efuses.o +obj-$(CONFIG_MICROCHIP_OTPC) += nvmem-microchip-otpc.o +nvmem-microchip-otpc-y := microchip-otpc.o diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c new file mode 100644 index 000000000000..5c5ac1bca074 --- /dev/null +++ b/drivers/nvmem/microchip-otpc.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * OTP Memory controller + * + * Copyright (C) 2022 Microchip Technology Inc. and its subsidiaries + * + * Author: Claudiu Beznea + */ + +#include +#include +#include +#include +#include +#include + +#define MCHP_OTPC_CR (0x0) +#define MCHP_OTPC_CR_READ BIT(6) +#define MCHP_OTPC_MR (0x4) +#define MCHP_OTPC_MR_ADDR GENMASK(31, 16) +#define MCHP_OTPC_AR (0x8) +#define MCHP_OTPC_SR (0xc) +#define MCHP_OTPC_SR_READ BIT(6) +#define MCHP_OTPC_HR (0x20) +#define MCHP_OTPC_HR_SIZE GENMASK(15, 8) +#define MCHP_OTPC_DR (0x24) + +#define MCHP_OTPC_NAME "mchp-otpc" +#define MCHP_OTPC_SIZE (11 * 1024) + +/** + * struct mchp_otpc - OTPC private data structure + * @base: base address + * @dev: struct device pointer + * @packets: list of packets in OTP memory + * @npackets: number of packets in OTP memory + */ +struct mchp_otpc { + void __iomem *base; + struct device *dev; + struct list_head packets; + u32 npackets; +}; + +/** + * struct mchp_otpc_packet - OTPC packet data structure + * @list: list head + * @id: packet ID + * @offset: packet offset (in words) in OTP memory + */ +struct mchp_otpc_packet { + struct list_head list; + u32 id; + u32 offset; +}; + +static struct mchp_otpc_packet *mchp_otpc_id_to_packet(struct mchp_otpc *otpc, + u32 id) +{ + struct mchp_otpc_packet *packet; + + if (id >= otpc->npackets) + return NULL; + + list_for_each_entry(packet, &otpc->packets, list) { + if (packet->id == id) + return packet; + } + + return NULL; +} + +static int mchp_otpc_prepare_read(struct mchp_otpc *otpc, + unsigned int offset) +{ + u32 tmp; + + /* Set address. */ + tmp = readl_relaxed(otpc->base + MCHP_OTPC_MR); + tmp &= ~MCHP_OTPC_MR_ADDR; + tmp |= FIELD_PREP(MCHP_OTPC_MR_ADDR, offset); + writel_relaxed(tmp, otpc->base + MCHP_OTPC_MR); + + /* Set read. */ + tmp = readl_relaxed(otpc->base + MCHP_OTPC_CR); + tmp |= MCHP_OTPC_CR_READ; + writel_relaxed(tmp, otpc->base + MCHP_OTPC_CR); + + /* Wait for packet to be transferred into temporary buffers. */ + return read_poll_timeout(readl_relaxed, tmp, !(tmp & MCHP_OTPC_SR_READ), + 10000, 2000, false, otpc->base + MCHP_OTPC_SR); +} + +/* + * OTPC memory is organized into packets. Each packets contains a header and + * a payload. Header is 4 bytes long and contains the size of the payload. + * Payload size varies. The memory footprint is something as follows: + * + * Memory offset Memory footprint Packet ID + * ------------- ---------------- --------- + * + * 0x0 +------------+ <-- packet 0 + * | header 0 | + * 0x4 +------------+ + * | payload 0 | + * . . + * . ... . + * . . + * offset1 +------------+ <-- packet 1 + * | header 1 | + * offset1 + 0x4 +------------+ + * | payload 1 | + * . . + * . ... . + * . . + * offset2 +------------+ <-- packet 2 + * . . + * . ... . + * . . + * offsetN +------------+ <-- packet N + * | header N | + * offsetN + 0x4 +------------+ + * | payload N | + * . . + * . ... . + * . . + * +------------+ + * + * where offset1, offset2, offsetN depends on the size of payload 0, payload 1, + * payload N-1. + * + * The access to memory is done on a per packet basis: the control registers + * need to be updated with an offset address (within a packet range) and the + * data registers will be update by controller with information contained by + * that packet. E.g. if control registers are updated with any address within + * the range [offset1, offset2) the data registers are updated by controller + * with packet 1. Header data is accessible though MCHP_OTPC_HR register. + * Payload data is accessible though MCHP_OTPC_DR and MCHP_OTPC_AR registers. + * There is no direct mapping b/w the offset requested by software and the + * offset returned by hardware. + * + * For this, the read function will return the first requested bytes in the + * packet. The user will have to be aware of the memory footprint before doing + * the read request. + */ +static int mchp_otpc_read(void *priv, unsigned int off, void *val, + size_t bytes) +{ + struct mchp_otpc *otpc = priv; + struct mchp_otpc_packet *packet; + u32 *buf = val; + u32 offset; + size_t len = 0; + int ret, payload_size; + + /* + * We reach this point with off being multiple of stride = 4 to + * be able to cross the subsystem. Inside the driver we use continuous + * unsigned integer numbers for packet id, thus devide off by 4 + * before passing it to mchp_otpc_id_to_packet(). + */ + packet = mchp_otpc_id_to_packet(otpc, off / 4); + if (!packet) + return -EINVAL; + offset = packet->offset; + + while (len < bytes) { + ret = mchp_otpc_prepare_read(otpc, offset); + if (ret) + return ret; + + /* Read and save header content. */ + *buf++ = readl_relaxed(otpc->base + MCHP_OTPC_HR); + len += sizeof(*buf); + offset++; + if (len >= bytes) + break; + + /* Read and save payload content. */ + payload_size = FIELD_GET(MCHP_OTPC_HR_SIZE, *(buf - 1)); + writel_relaxed(0UL, otpc->base + MCHP_OTPC_AR); + do { + *buf++ = readl_relaxed(otpc->base + MCHP_OTPC_DR); + len += sizeof(*buf); + offset++; + payload_size--; + } while (payload_size >= 0 && len < bytes); + } + + return 0; +} + +static int mchp_otpc_init_packets_list(struct mchp_otpc *otpc, u32 *size) +{ + struct mchp_otpc_packet *packet; + u32 word, word_pos = 0, id = 0, npackets = 0, payload_size; + int ret; + + INIT_LIST_HEAD(&otpc->packets); + *size = 0; + + while (*size < MCHP_OTPC_SIZE) { + ret = mchp_otpc_prepare_read(otpc, word_pos); + if (ret) + return ret; + + word = readl_relaxed(otpc->base + MCHP_OTPC_HR); + payload_size = FIELD_GET(MCHP_OTPC_HR_SIZE, word); + if (!payload_size) + break; + + packet = devm_kzalloc(otpc->dev, sizeof(*packet), GFP_KERNEL); + if (!packet) + return -ENOMEM; + + packet->id = id++; + packet->offset = word_pos; + INIT_LIST_HEAD(&packet->list); + list_add_tail(&packet->list, &otpc->packets); + + /* Count size by adding header and paload sizes. */ + *size += 4 * (payload_size + 1); + /* Next word: this packet (header, payload) position + 1. */ + word_pos += payload_size + 2; + + npackets++; + } + + otpc->npackets = npackets; + + return 0; +} + +static struct nvmem_config mchp_nvmem_config = { + .name = MCHP_OTPC_NAME, + .type = NVMEM_TYPE_OTP, + .read_only = true, + .word_size = 4, + .stride = 4, + .reg_read = mchp_otpc_read, +}; + +static int mchp_otpc_probe(struct platform_device *pdev) +{ + struct nvmem_device *nvmem; + struct mchp_otpc *otpc; + u32 size; + int ret; + + otpc = devm_kzalloc(&pdev->dev, sizeof(*otpc), GFP_KERNEL); + if (!otpc) + return -ENOMEM; + + otpc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(otpc->base)) + return PTR_ERR(otpc->base); + + otpc->dev = &pdev->dev; + ret = mchp_otpc_init_packets_list(otpc, &size); + if (ret) + return ret; + + mchp_nvmem_config.dev = otpc->dev; + mchp_nvmem_config.size = size; + mchp_nvmem_config.priv = otpc; + nvmem = devm_nvmem_register(&pdev->dev, &mchp_nvmem_config); + + return PTR_ERR_OR_ZERO(nvmem); +} + +static const struct of_device_id mchp_otpc_ids[] = { + { .compatible = "microchip,sama7g5-otpc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, mchp_otpc_ids); + +static struct platform_driver mchp_otpc_driver = { + .probe = mchp_otpc_probe, + .driver = { + .name = MCHP_OTPC_NAME, + .of_match_table = of_match_ptr(mchp_otpc_ids), + }, +}; +module_platform_driver(mchp_otpc_driver); + +MODULE_AUTHOR("Claudiu Beznea "); +MODULE_DESCRIPTION("Microchip SAMA7G5 OTPC driver"); +MODULE_LICENSE("GPL");