From patchwork Wed Feb 2 14:48:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Winiarska, Iwona" X-Patchwork-Id: 12733124 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 F33E5C433F5 for ; Wed, 2 Feb 2022 14:54:42 +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=hk86xjEx2d3j52Qtym2hsp+gCVCnSEyqn91Cg8WRnFg=; b=HRaWxNNox0hRDw DJueKuQRdbSH2tatHMf3ffE7WPzNMl14lW+WaBE7bxi+lTHgyxQS6/v10aaCmQ1EYS5qeUQeGyIwy 5q12XXBWABTCqFPyfolZXVPly0MjgSnuAxF11VjC6Gc3zbDRP+xGGrYrp7GMykO3435pkMarYTyAc r4yEgzVoFhp+g+SKkgk06fGKcQ72p5LmYtw8EO7wRiSBKDynhMK0/EHfmrtEvlsMLRDMJO/p0tJjQ vWOhtQ0p2W8JvEbtZMemKo+3wcVRYu3MhX4wiDboaCWTMJOAONJcPAzzTfVkj+LqioMzSc5EpQYgE +bT8hunBN5prDW1ha6ew==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nFH07-00FoqU-51; Wed, 02 Feb 2022 14:52:51 +0000 Received: from mga05.intel.com ([192.55.52.43]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nFGzx-00Fon9-HZ for linux-arm-kernel@lists.infradead.org; Wed, 02 Feb 2022 14:52:45 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643813561; x=1675349561; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uhbZDJfQ4cuQvhmM/sqpJ6kpDvtw4zEguJRDuAbGoA4=; b=ZZVPs1lR/jOsVvMw1770bk7UPGueeIlQtA0/OylWHX2nL+m3gkaOCEDV 4mvmYddNDMIwXaEdkVp3HHjbV0LqKHlFRV52u/V5MGeok2AitaHq6YXBQ 6Lu7wzRZKI9aW9L6oAy+iKm1tp+qTiuWF3gCl184NQ5q3hg9MRKLmn/CH Wv5hO+b/O1NejVS233YaZpqMpeMGVb/giUXFaeN5/IXle1hIVds5jLrp7 ux5lBG4j+JyY2h7RJF093C9UPdrXAIjM+Yz+kG9bckqUrgQxCkca5UByg V56mRb90ygHU8s11znEBUWaYt/Tu5qBETIcJnKoJ9L17LixEjkYoT/jDy g==; X-IronPort-AV: E=McAfee;i="6200,9189,10245"; a="334288465" X-IronPort-AV: E=Sophos;i="5.88,337,1635231600"; d="scan'208";a="334288465" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 06:52:40 -0800 X-IronPort-AV: E=Sophos;i="5.88,337,1635231600"; d="scan'208";a="482848461" Received: from mwnuczyn-mobl.ger.corp.intel.com (HELO localhost) ([10.249.137.160]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Feb 2022 06:52:27 -0800 From: Iwona Winiarska To: linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, Greg Kroah-Hartman Cc: devicetree@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, Rob Herring , Joel Stanley , Andrew Jeffery , Jean Delvare , Guenter Roeck , Arnd Bergmann , Olof Johansson , Jonathan Corbet , Borislav Petkov , Pierre-Louis Bossart , Tony Luck , Andy Shevchenko , Dan Williams , Randy Dunlap , Zev Weiss , David Muller , Dave Hansen , Billy Tsai , Jae Hyun Yoo , Iwona Winiarska Subject: [PATCH v7 05/13] peci: Add peci-aspeed controller driver Date: Wed, 2 Feb 2022 15:48:30 +0100 Message-Id: <20220202144838.163875-6-iwona.winiarska@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220202144838.163875-1-iwona.winiarska@intel.com> References: <20220202144838.163875-1-iwona.winiarska@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220202_065241_651041_DBB77772 X-CRM114-Status: GOOD ( 29.19 ) 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 From: Jae Hyun Yoo ASPEED AST24xx/AST25xx/AST26xx SoCs support the PECI electrical interface (a.k.a PECI wire) that provides a communication channel with Intel processors. This driver allows BMC to discover devices connected to it and communicate with them using PECI protocol. Signed-off-by: Jae Hyun Yoo Co-developed-by: Iwona Winiarska Signed-off-by: Iwona Winiarska Reviewed-by: Pierre-Louis Bossart Reviewed-by: Joel Stanley --- MAINTAINERS | 8 + drivers/peci/Kconfig | 6 + drivers/peci/Makefile | 3 + drivers/peci/controller/Kconfig | 18 + drivers/peci/controller/Makefile | 3 + drivers/peci/controller/peci-aspeed.c | 599 ++++++++++++++++++++++++++ 6 files changed, 637 insertions(+) create mode 100644 drivers/peci/controller/Kconfig create mode 100644 drivers/peci/controller/Makefile create mode 100644 drivers/peci/controller/peci-aspeed.c diff --git a/MAINTAINERS b/MAINTAINERS index 0fd6c9f40406..b8511e71e55b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2986,6 +2986,14 @@ S: Maintained F: Documentation/devicetree/bindings/net/asix,ax88796c.yaml F: drivers/net/ethernet/asix/ax88796c_* +ASPEED PECI CONTROLLER +M: Iwona Winiarska +L: linux-aspeed@lists.ozlabs.org (moderated for non-subscribers) +L: openbmc@lists.ozlabs.org (moderated for non-subscribers) +S: Supported +F: Documentation/devicetree/bindings/peci/peci-aspeed.yaml +F: drivers/peci/controller/peci-aspeed.c + ASPEED PINCTRL DRIVERS M: Andrew Jeffery L: linux-aspeed@lists.ozlabs.org (moderated for non-subscribers) diff --git a/drivers/peci/Kconfig b/drivers/peci/Kconfig index 71a4ad81225a..99279df97a78 100644 --- a/drivers/peci/Kconfig +++ b/drivers/peci/Kconfig @@ -13,3 +13,9 @@ menuconfig PECI This support is also available as a module. If so, the module will be called peci. + +if PECI + +source "drivers/peci/controller/Kconfig" + +endif # PECI diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile index e789a354e842..926d8df15cbd 100644 --- a/drivers/peci/Makefile +++ b/drivers/peci/Makefile @@ -3,3 +3,6 @@ # Core functionality peci-y := core.o obj-$(CONFIG_PECI) += peci.o + +# Hardware specific bus drivers +obj-y += controller/ diff --git a/drivers/peci/controller/Kconfig b/drivers/peci/controller/Kconfig new file mode 100644 index 000000000000..2fc5e2abb74a --- /dev/null +++ b/drivers/peci/controller/Kconfig @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config PECI_ASPEED + tristate "ASPEED PECI support" + depends on ARCH_ASPEED || COMPILE_TEST + depends on OF + depends on HAS_IOMEM + depends on COMMON_CLK + help + This option enables PECI controller driver for ASPEED AST2400, + AST2500 and AST2600 SoCs. It allows BMC to discover devices + connected to it, and communicate with them using PECI protocol. + + Say Y here if your system runs on ASPEED SoC and you are using it + as BMC for Intel platform. + + This driver can also be built as a module. If so, the module will + be called peci-aspeed. diff --git a/drivers/peci/controller/Makefile b/drivers/peci/controller/Makefile new file mode 100644 index 000000000000..022c28ef1bf0 --- /dev/null +++ b/drivers/peci/controller/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_PECI_ASPEED) += peci-aspeed.o diff --git a/drivers/peci/controller/peci-aspeed.c b/drivers/peci/controller/peci-aspeed.c new file mode 100644 index 000000000000..1925ddc13f00 --- /dev/null +++ b/drivers/peci/controller/peci-aspeed.c @@ -0,0 +1,599 @@ +// SPDX-License-Identifier: GPL-2.0-only +// Copyright (c) 2012-2017 ASPEED Technology Inc. +// Copyright (c) 2018-2021 Intel Corporation + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* ASPEED PECI Registers */ +/* Control Register */ +#define ASPEED_PECI_CTRL 0x00 +#define ASPEED_PECI_CTRL_SAMPLING_MASK GENMASK(19, 16) +#define ASPEED_PECI_CTRL_RD_MODE_MASK GENMASK(13, 12) +#define ASPEED_PECI_CTRL_RD_MODE_DBG BIT(13) +#define ASPEED_PECI_CTRL_RD_MODE_COUNT BIT(12) +#define ASPEED_PECI_CTRL_CLK_SRC_HCLK BIT(11) +#define ASPEED_PECI_CTRL_CLK_DIV_MASK GENMASK(10, 8) +#define ASPEED_PECI_CTRL_INVERT_OUT BIT(7) +#define ASPEED_PECI_CTRL_INVERT_IN BIT(6) +#define ASPEED_PECI_CTRL_BUS_CONTENTION_EN BIT(5) +#define ASPEED_PECI_CTRL_PECI_EN BIT(4) +#define ASPEED_PECI_CTRL_PECI_CLK_EN BIT(0) + +/* Timing Negotiation Register */ +#define ASPEED_PECI_TIMING_NEGOTIATION 0x04 +#define ASPEED_PECI_T_NEGO_MSG_MASK GENMASK(15, 8) +#define ASPEED_PECI_T_NEGO_ADDR_MASK GENMASK(7, 0) + +/* Command Register */ +#define ASPEED_PECI_CMD 0x08 +#define ASPEED_PECI_CMD_PIN_MONITORING BIT(31) +#define ASPEED_PECI_CMD_STS_MASK GENMASK(27, 24) +#define ASPEED_PECI_CMD_STS_ADDR_T_NEGO 0x3 +#define ASPEED_PECI_CMD_IDLE_MASK \ + (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MONITORING) +#define ASPEED_PECI_CMD_FIRE BIT(0) + +/* Read/Write Length Register */ +#define ASPEED_PECI_RW_LENGTH 0x0c +#define ASPEED_PECI_AW_FCS_EN BIT(31) +#define ASPEED_PECI_RD_LEN_MASK GENMASK(23, 16) +#define ASPEED_PECI_WR_LEN_MASK GENMASK(15, 8) +#define ASPEED_PECI_TARGET_ADDR_MASK GENMASK(7, 0) + +/* Expected FCS Data Register */ +#define ASPEED_PECI_EXPECTED_FCS 0x10 +#define ASPEED_PECI_EXPECTED_RD_FCS_MASK GENMASK(23, 16) +#define ASPEED_PECI_EXPECTED_AW_FCS_AUTO_MASK GENMASK(15, 8) +#define ASPEED_PECI_EXPECTED_WR_FCS_MASK GENMASK(7, 0) + +/* Captured FCS Data Register */ +#define ASPEED_PECI_CAPTURED_FCS 0x14 +#define ASPEED_PECI_CAPTURED_RD_FCS_MASK GENMASK(23, 16) +#define ASPEED_PECI_CAPTURED_WR_FCS_MASK GENMASK(7, 0) + +/* Interrupt Register */ +#define ASPEED_PECI_INT_CTRL 0x18 +#define ASPEED_PECI_TIMING_NEGO_SEL_MASK GENMASK(31, 30) +#define ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO 0 +#define ASPEED_PECI_2ND_BIT_OF_ADDR_NEGO 1 +#define ASPEED_PECI_MESSAGE_NEGO 2 +#define ASPEED_PECI_INT_MASK GENMASK(4, 0) +#define ASPEED_PECI_INT_BUS_TIMEOUT BIT(4) +#define ASPEED_PECI_INT_BUS_CONTENTION BIT(3) +#define ASPEED_PECI_INT_WR_FCS_BAD BIT(2) +#define ASPEED_PECI_INT_WR_FCS_ABORT BIT(1) +#define ASPEED_PECI_INT_CMD_DONE BIT(0) + +/* Interrupt Status Register */ +#define ASPEED_PECI_INT_STS 0x1c +#define ASPEED_PECI_INT_TIMING_RESULT_MASK GENMASK(29, 16) + /* bits[4..0]: Same bit fields in the 'Interrupt Register' */ + +/* Rx/Tx Data Buffer Registers */ +#define ASPEED_PECI_WR_DATA0 0x20 +#define ASPEED_PECI_WR_DATA1 0x24 +#define ASPEED_PECI_WR_DATA2 0x28 +#define ASPEED_PECI_WR_DATA3 0x2c +#define ASPEED_PECI_RD_DATA0 0x30 +#define ASPEED_PECI_RD_DATA1 0x34 +#define ASPEED_PECI_RD_DATA2 0x38 +#define ASPEED_PECI_RD_DATA3 0x3c +#define ASPEED_PECI_WR_DATA4 0x40 +#define ASPEED_PECI_WR_DATA5 0x44 +#define ASPEED_PECI_WR_DATA6 0x48 +#define ASPEED_PECI_WR_DATA7 0x4c +#define ASPEED_PECI_RD_DATA4 0x50 +#define ASPEED_PECI_RD_DATA5 0x54 +#define ASPEED_PECI_RD_DATA6 0x58 +#define ASPEED_PECI_RD_DATA7 0x5c +#define ASPEED_PECI_DATA_BUF_SIZE_MAX 32 + +/* Timing Negotiation */ +#define ASPEED_PECI_CLK_FREQUENCY_MIN 2000 +#define ASPEED_PECI_CLK_FREQUENCY_DEFAULT 1000000 +#define ASPEED_PECI_CLK_FREQUENCY_MAX 2000000 +#define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT 8 +/* Timeout */ +#define ASPEED_PECI_IDLE_CHECK_TIMEOUT_US (50 * USEC_PER_MSEC) +#define ASPEED_PECI_IDLE_CHECK_INTERVAL_US (10 * USEC_PER_MSEC) +#define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT 1000 +#define ASPEED_PECI_CMD_TIMEOUT_MS_MAX 1000 + +#define ASPEED_PECI_CLK_DIV1(msg_timing) (4 * (msg_timing) + 1) +#define ASPEED_PECI_CLK_DIV2(clk_div_exp) BIT(clk_div_exp) +#define ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp) \ + (4 * ASPEED_PECI_CLK_DIV1(msg_timing) * ASPEED_PECI_CLK_DIV2(clk_div_exp)) + +struct aspeed_peci { + struct peci_controller *controller; + struct device *dev; + void __iomem *base; + struct reset_control *rst; + int irq; + spinlock_t lock; /* to sync completion status handling */ + struct completion xfer_complete; + struct clk *clk; + u32 clk_frequency; + u32 status; + u32 cmd_timeout_ms; +}; + +struct clk_aspeed_peci { + struct clk_hw hw; + struct aspeed_peci *aspeed_peci; +}; + +static void aspeed_peci_controller_enable(struct aspeed_peci *priv) +{ + u32 val = readl(priv->base + ASPEED_PECI_CTRL); + + val |= ASPEED_PECI_CTRL_PECI_CLK_EN; + val |= ASPEED_PECI_CTRL_PECI_EN; + + writel(val, priv->base + ASPEED_PECI_CTRL); +} + +static void aspeed_peci_init_regs(struct aspeed_peci *priv) +{ + u32 val; + + /* Clear interrupts */ + writel(ASPEED_PECI_INT_MASK, priv->base + ASPEED_PECI_INT_STS); + + /* Set timing negotiation mode and enable interrupts */ + val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO); + val |= ASPEED_PECI_INT_MASK; + writel(val, priv->base + ASPEED_PECI_INT_CTRL); + + val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT); + writel(val, priv->base + ASPEED_PECI_CTRL); +} + +static int aspeed_peci_check_idle(struct aspeed_peci *priv) +{ + u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD); + int ret; + + /* + * Under normal circumstances, we expect to be idle here. + * In case there were any errors/timeouts that led to the situation + * where the hardware is not in idle state - we need to reset and + * reinitialize it to avoid potential controller hang. + */ + if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) { + ret = reset_control_assert(priv->rst); + if (ret) { + dev_err(priv->dev, "cannot assert reset control\n"); + return ret; + } + + ret = reset_control_deassert(priv->rst); + if (ret) { + dev_err(priv->dev, "cannot deassert reset control\n"); + return ret; + } + + aspeed_peci_init_regs(priv); + + ret = clk_set_rate(priv->clk, priv->clk_frequency); + if (ret < 0) { + dev_err(priv->dev, "cannot set clock frequency\n"); + return ret; + } + + aspeed_peci_controller_enable(priv); + } + + return readl_poll_timeout(priv->base + ASPEED_PECI_CMD, + cmd_sts, + !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK), + ASPEED_PECI_IDLE_CHECK_INTERVAL_US, + ASPEED_PECI_IDLE_CHECK_TIMEOUT_US); +} + +static int aspeed_peci_xfer(struct peci_controller *controller, + u8 addr, struct peci_request *req) +{ + struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent); + unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms); + u32 peci_head; + int ret, i; + + if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX || + req->rx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX) + return -EINVAL; + + /* Check command sts and bus idle state */ + ret = aspeed_peci_check_idle(priv); + if (ret) + return ret; /* -ETIMEDOUT */ + + spin_lock_irq(&priv->lock); + reinit_completion(&priv->xfer_complete); + + peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) | + FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) | + FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len); + + writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH); + + for (i = 0; i < req->tx.len; i += 4) { + u32 reg = (i < 16 ? ASPEED_PECI_WR_DATA0 : ASPEED_PECI_WR_DATA4) + i % 16; + + writel(get_unaligned_le32(&req->tx.buf[i]), priv->base + reg); + } + +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) + dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head); + print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len); +#endif + + priv->status = 0; + writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD); + spin_unlock_irq(&priv->lock); + + ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout); + if (ret < 0) + return ret; + + if (ret == 0) { + dev_dbg(priv->dev, "timeout waiting for a response\n"); + return -ETIMEDOUT; + } + + spin_lock_irq(&priv->lock); + + if (priv->status != ASPEED_PECI_INT_CMD_DONE) { + spin_unlock_irq(&priv->lock); + dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status); + return -EIO; + } + + spin_unlock_irq(&priv->lock); + + /* + * We need to use dword reads for register access, make sure that the + * buffer size is multiple of 4-bytes. + */ + BUILD_BUG_ON(PECI_REQUEST_MAX_BUF_SIZE % 4); + + for (i = 0; i < req->rx.len; i += 4) { + u32 reg = (i < 16 ? ASPEED_PECI_RD_DATA0 : ASPEED_PECI_RD_DATA4) + i % 16; + u32 rx_data = readl(priv->base + reg); + + put_unaligned_le32(rx_data, &req->rx.buf[i]); + } + +#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) + print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len); +#endif + return 0; +} + +static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg) +{ + struct aspeed_peci *priv = arg; + u32 status; + + spin_lock(&priv->lock); + status = readl(priv->base + ASPEED_PECI_INT_STS); + writel(status, priv->base + ASPEED_PECI_INT_STS); + priv->status |= (status & ASPEED_PECI_INT_MASK); + + /* + * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit + * set even in an error case. + */ + if (status & ASPEED_PECI_INT_CMD_DONE) + complete(&priv->xfer_complete); + + writel(0, priv->base + ASPEED_PECI_CMD); + + spin_unlock(&priv->lock); + + return IRQ_HANDLED; +} + +static void clk_aspeed_peci_find_div_values(unsigned long rate, int *msg_timing, int *clk_div_exp) +{ + unsigned long best_diff = ~0ul, diff; + int msg_timing_temp, clk_div_exp_temp, i, j; + + for (i = 1; i <= 255; i++) + for (j = 0; j < 8; j++) { + diff = abs(rate - ASPEED_PECI_CLK_DIV1(i) * ASPEED_PECI_CLK_DIV2(j)); + if (diff < best_diff) { + msg_timing_temp = i; + clk_div_exp_temp = j; + best_diff = diff; + } + } + + *msg_timing = msg_timing_temp; + *clk_div_exp = clk_div_exp_temp; +} + +static int clk_aspeed_peci_get_div(unsigned long rate, const unsigned long *prate) +{ + unsigned long this_rate = *prate / (4 * rate); + int msg_timing, clk_div_exp; + + clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp); + + return ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp); +} + +static int clk_aspeed_peci_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long prate) +{ + struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw); + struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci; + unsigned long this_rate = prate / (4 * rate); + int clk_div_exp, msg_timing; + u32 val; + + clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp); + + val = readl(aspeed_peci->base + ASPEED_PECI_CTRL); + val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, clk_div_exp); + writel(val, aspeed_peci->base + ASPEED_PECI_CTRL); + + val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, msg_timing); + val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, msg_timing); + writel(val, aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION); + + return 0; +} + +static long clk_aspeed_peci_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + int div = clk_aspeed_peci_get_div(rate, prate); + + return DIV_ROUND_UP_ULL(*prate, div); +} + +static unsigned long clk_aspeed_peci_recalc_rate(struct clk_hw *hw, unsigned long prate) +{ + struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw); + struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci; + int div, msg_timing, addr_timing, clk_div_exp; + u32 reg; + + reg = readl(aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION); + msg_timing = FIELD_GET(ASPEED_PECI_T_NEGO_MSG_MASK, reg); + addr_timing = FIELD_GET(ASPEED_PECI_T_NEGO_ADDR_MASK, reg); + + if (msg_timing != addr_timing) + return 0; + + reg = readl(aspeed_peci->base + ASPEED_PECI_CTRL); + clk_div_exp = FIELD_GET(ASPEED_PECI_CTRL_CLK_DIV_MASK, reg); + + div = ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp); + + return DIV_ROUND_UP_ULL(prate, div); +} + +static const struct clk_ops clk_aspeed_peci_ops = { + .set_rate = clk_aspeed_peci_set_rate, + .round_rate = clk_aspeed_peci_round_rate, + .recalc_rate = clk_aspeed_peci_recalc_rate, +}; + +/* + * PECI HW contains a clock divider which is a combination of: + * div0: 4 (fixed divider) + * div1: x + 1 + * div2: 1 << y + * In other words, out_clk = in_clk / (div0 * div1 * div2) + * The resulting frequency is used by PECI Controller to drive the PECI bus to + * negotiate optimal transfer rate. + */ +static struct clk *devm_aspeed_peci_register_clk_div(struct device *dev, struct clk *parent, + struct aspeed_peci *priv) +{ + struct clk_aspeed_peci *peci_clk; + struct clk_init_data init; + const char *parent_name; + char name[32]; + int ret; + + snprintf(name, sizeof(name), "%s_div", dev_name(dev)); + + parent_name = __clk_get_name(parent); + + init.ops = &clk_aspeed_peci_ops; + init.name = name; + init.parent_names = (const char* []) { parent_name }; + init.num_parents = 1; + init.flags = 0; + + peci_clk = devm_kzalloc(dev, sizeof(struct clk_aspeed_peci), GFP_KERNEL); + if (!peci_clk) + return ERR_PTR(-ENOMEM); + + peci_clk->hw.init = &init; + peci_clk->aspeed_peci = priv; + + ret = devm_clk_hw_register(dev, &peci_clk->hw); + if (ret) + return ERR_PTR(ret); + + return peci_clk->hw.clk; +} + +static void aspeed_peci_property_sanitize(struct device *dev, const char *propname, + u32 min, u32 max, u32 default_val, u32 *propval) +{ + u32 val; + int ret; + + ret = device_property_read_u32(dev, propname, &val); + if (ret) { + val = default_val; + } else if (val > max || val < min) { + dev_warn(dev, "invalid %s: %u, falling back to: %u\n", + propname, val, default_val); + + val = default_val; + } + + *propval = val; +} + +static void aspeed_peci_property_setup(struct aspeed_peci *priv) +{ + aspeed_peci_property_sanitize(priv->dev, "clock-frequency", + ASPEED_PECI_CLK_FREQUENCY_MIN, ASPEED_PECI_CLK_FREQUENCY_MAX, + ASPEED_PECI_CLK_FREQUENCY_DEFAULT, &priv->clk_frequency); + aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms", + 1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX, + ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms); +} + +static struct peci_controller_ops aspeed_ops = { + .xfer = aspeed_peci_xfer, +}; + +static void aspeed_peci_reset_control_release(void *data) +{ + reset_control_assert(data); +} + +static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst) +{ + int ret; + + ret = reset_control_deassert(rst); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst); +} + +static void aspeed_peci_clk_release(void *data) +{ + clk_disable_unprepare(data); +} + +static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk) +{ + int ret; + + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk); +} + +static int aspeed_peci_probe(struct platform_device *pdev) +{ + struct peci_controller *controller; + struct aspeed_peci *priv; + struct clk *ref_clk; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + dev_set_drvdata(priv->dev, priv); + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + priv->irq = platform_get_irq(pdev, 0); + if (!priv->irq) + return priv->irq; + + ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler, + 0, "peci-aspeed", priv); + if (ret) + return ret; + + init_completion(&priv->xfer_complete); + spin_lock_init(&priv->lock); + + priv->rst = devm_reset_control_get(&pdev->dev, NULL); + if (IS_ERR(priv->rst)) + return dev_err_probe(priv->dev, PTR_ERR(priv->rst), + "failed to get reset control\n"); + + ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst); + if (ret) + return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n"); + + aspeed_peci_property_setup(priv); + + aspeed_peci_init_regs(priv); + + ref_clk = devm_clk_get(priv->dev, NULL); + if (IS_ERR(ref_clk)) + return dev_err_probe(priv->dev, PTR_ERR(ref_clk), "failed to get ref clock\n"); + + priv->clk = devm_aspeed_peci_register_clk_div(priv->dev, ref_clk, priv); + if (IS_ERR(priv->clk)) + return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "cannot register clock\n"); + + ret = clk_set_rate(priv->clk, priv->clk_frequency); + if (ret < 0) + return dev_err_probe(priv->dev, ret, "cannot set clock frequency\n"); + + ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk); + if (ret) + return dev_err_probe(priv->dev, ret, "failed to enable clock\n"); + + aspeed_peci_controller_enable(priv); + + controller = devm_peci_controller_add(priv->dev, &aspeed_ops); + if (IS_ERR(controller)) + return dev_err_probe(priv->dev, PTR_ERR(controller), + "failed to add aspeed peci controller\n"); + + priv->controller = controller; + + return 0; +} + +static const struct of_device_id aspeed_peci_of_table[] = { + { .compatible = "aspeed,ast2400-peci", }, + { .compatible = "aspeed,ast2500-peci", }, + { .compatible = "aspeed,ast2600-peci", }, + { } +}; +MODULE_DEVICE_TABLE(of, aspeed_peci_of_table); + +static struct platform_driver aspeed_peci_driver = { + .probe = aspeed_peci_probe, + .driver = { + .name = "peci-aspeed", + .of_match_table = aspeed_peci_of_table, + }, +}; +module_platform_driver(aspeed_peci_driver); + +MODULE_AUTHOR("Ryan Chen "); +MODULE_AUTHOR("Jae Hyun Yoo "); +MODULE_DESCRIPTION("ASPEED PECI driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(PECI);