From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 48147C531C9 for ; Fri, 24 Jul 2026 05:18:56 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4h5x9V517Sz2yYq; Fri, 24 Jul 2026 15:18:54 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=211.20.114.72 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1784784722; cv=none; b=Nbek9ZejEztAozvwt+vSImBRkxcBQRmjxbA8xkikw4g9oGThuaiuBcI71FrjgP5FqYVW8PtlC/UO7hyCPFfNk2rx0PUjq0wo5Ow+kjhcqvufmON0vtBgW2bfTsE7i8Ma2ADZCEN7dUdqaN3b6Z2cgJEMgQB/q3RzGOhnBnP7tf0oP3HnmxUsGy8M0WA/zNDvsumZ/h+g249woi9q4PNiGmVsVmOBFr89Lkz0z3KqXxuV2DMuGYQ60bvdDhzgw9Oe3xAQ7bX7sH9oz4nqcLYzqDS70xJIppY2FbA8VBj2Q3D0uzS9wAy3Upxo+7pBGyCVq7As0SIh0zbubpXdjsm1lw== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1784784722; c=relaxed/relaxed; bh=GQCEk4uZRUPDKEnKk78GF0miz0R82zKAyiCG3x64wtM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=UqLGzhgrdU++LmpNu32xdMizRPhs808ftgGRTcBXHGrHUe7EBh0zj2MwYQmXuJVahuM1TMpw/zUoCtidyQU/G120ykXONxGl7WPfucSmm/KS2VmUA6T8omWuDBDAal5xZbAiHhFIPUntWoNM/ZAHWbkjRl8l17FJKlQCmMKYo+IlO3NNWONzQwk5ZwbSDfCyJD12vOJX5qzu+NT7Wh+qlMzPx38shZPBdRR7sLc+Kin2gdXCG3o55b2E9z1uKdEzezYyDS9szjGo4SuRaDGwmZ2feIWxP93ku52LuOFxYM/NrFL7fYo+xX+7goX7KeTbzfCfhR9P2BeumyrIYkJwjg== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com; spf=pass (client-ip=211.20.114.72; helo=twmbx01.aspeedtech.com; envelope-from=yc_hsieh@aspeedtech.com; receiver=lists.ozlabs.org) smtp.mailfrom=aspeedtech.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=aspeedtech.com (client-ip=211.20.114.72; helo=twmbx01.aspeedtech.com; envelope-from=yc_hsieh@aspeedtech.com; receiver=lists.ozlabs.org) Received: from twmbx01.aspeedtech.com (mail.aspeedtech.com [211.20.114.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4h5KW55pVbz2xqJ for ; Thu, 23 Jul 2026 15:32:01 +1000 (AEST) Received: from TWMBX01.aspeed.com (192.168.0.62) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.10; Thu, 23 Jul 2026 13:31:42 +0800 Received: from [127.0.1.1] (192.168.10.13) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server id 15.2.1748.10 via Frontend Transport; Thu, 23 Jul 2026 13:31:42 +0800 From: Yu-Che Hsieh Date: Thu, 23 Jul 2026 13:31:38 +0800 Subject: [PATCH RFC 2/2] ipmi: kcs_bmc_aspeed: Support multiple LPC controller instances X-Mailing-List: linux-aspeed@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-ID: <20260723-upstream_kcs_multiple_lpc-v1-2-d918b5270b86@aspeedtech.com> References: <20260723-upstream_kcs_multiple_lpc-v1-0-d918b5270b86@aspeedtech.com> In-Reply-To: <20260723-upstream_kcs_multiple_lpc-v1-0-d918b5270b86@aspeedtech.com> To: Lee Jones , Rob Herring , "Krzysztof Kozlowski" , Conor Dooley , "Joel Stanley" , Andrew Jeffery , Chia-Wei Wang , Corey Minyard CC: Andrew Jeffery , , , , , , Yu-Che Hsieh X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1784784702; l=6125; i=yc_hsieh@aspeedtech.com; s=20260721; h=from:subject:message-id; bh=WCkY6ru4QaUOU33knVeXbs5BBFO1adD73YX6nr6ufaE=; b=qu3mKDSW024Lstm35DdVqbd5L/9osovxUg4aLC1RhM91zWU5pAcLSM3Ve5NV8KmLvLiOIYBnc kLGcSjXCcLPBi+RO4zDu5VLMol13Xw2XyHWOIh4XOPQ+wxRrbAT+OP+ X-Developer-Key: i=yc_hsieh@aspeedtech.com; a=ed25519; pk=7KnU2ozXGF2IATT+Hvu7RbRwPxBA3/b+zhfM+UsPJMs= Some SoCs (e.g. AST2700) expose more than one physical LPC controller, each instantiating its own independent set of KCS0-KCS3 channels using identical IDR/ODR/STR register offsets. kcs_bmc_device::channel is currently overloaded to serve two distinct purposes: selecting which HICR0/HICR2/HICRB bit-group to touch within a single LPC controller's register file, and naming the misc chardev (/dev/ipmi-kcsN) exposed to userspace, which must be unique system-wide. The two purposes happen to share the same value only because the driver has so far only had to support SoCs with a single LPC controller. On a multi-controller SoC, KCS0 on every LPC controller computes to the same channel number, and whichever instance probes second fails to register its chardev. Split the two roles: keep a new driver-private `channel` field (1..4) in struct aspeed_kcs_bmc for register access, leaving all the HICR/IBFIE/LPCxE switch statements operating on it, and derive kcs_bmc_device::channel as `bank * KCS_CHANNEL_MAX + channel`, where `bank` identifies which LPC controller instance a KCS device belongs to. `bank` is obtained from an optional "lpcN" alias on the LPC controller node via of_alias_get_id(), following the same convention already used by mmc/i2c/spi/serial for instance numbering. SoCs with a single LPC controller, and existing DTs that don't declare the alias, fall back to bank 0, so /dev/ipmi-kcsN naming is unchanged for all existing boards. Signed-off-by: Yu-Che Hsieh --- drivers/char/ipmi/kcs_bmc_aspeed.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/drivers/char/ipmi/kcs_bmc_aspeed.c b/drivers/char/ipmi/kcs_bmc_aspeed.c index a13a3470c17a..591c11a44503 100644 --- a/drivers/char/ipmi/kcs_bmc_aspeed.c +++ b/drivers/char/ipmi/kcs_bmc_aspeed.c @@ -125,6 +125,8 @@ struct aspeed_kcs_bmc { bool remove; struct timer_list timer; } obe; + + u32 channel; }; static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc) @@ -167,7 +169,7 @@ static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data) if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq) return; - switch (kcs_bmc->channel) { + switch (priv->channel) { case 1: switch (priv->upstream_irq.id) { case 12: @@ -232,7 +234,7 @@ static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], if (WARN_ON(nr_addrs < 1 || nr_addrs > 2)) return -EINVAL; - switch (priv->kcs_bmc.channel) { + switch (priv->channel) { case 1: regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0); regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8); @@ -315,7 +317,7 @@ static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u priv->upstream_irq.mode = aspeed_kcs_irq_serirq; priv->upstream_irq.id = id; - switch (priv->kcs_bmc.channel) { + switch (priv->channel) { case 1: /* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */ break; @@ -347,7 +349,7 @@ static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u default: dev_warn(priv->kcs_bmc.dev, "SerIRQ configuration not supported on KCS channel %d\n", - priv->kcs_bmc.channel); + priv->channel); return -EINVAL; } @@ -358,7 +360,7 @@ static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enabl { struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc); - switch (kcs_bmc->channel) { + switch (priv->channel) { case 1: regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E); return; @@ -374,7 +376,7 @@ static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enabl regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E); return; default: - pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel); + pr_warn("%s: Unsupported channel: %d", __func__, priv->channel); return; } } @@ -435,7 +437,7 @@ static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, if (mask & KCS_BMC_EVENT_TYPE_IBF) { const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF); - switch (kcs_bmc->channel) { + switch (priv->channel) { case 1: regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1, enable * LPC_HICR2_IBFIE1); @@ -453,7 +455,7 @@ static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, enable * LPC_HICRB_IBFIE4); return; default: - pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel); + pr_warn("%s: Unsupported channel: %d", __func__, priv->channel); return; } } @@ -526,6 +528,17 @@ static int aspeed_kcs_of_get_channel(struct platform_device *pdev) return -EINVAL; } +static int aspeed_kcs_of_get_bank(struct device_node *lpc_np) +{ + int id; + + id = of_alias_get_id(lpc_np, "lpc"); + if (id < 0) + return 0; + + return id; +} + static int aspeed_kcs_of_get_io_address(struct platform_device *pdev, u32 addrs[2]) { @@ -559,7 +572,7 @@ static int aspeed_kcs_probe(struct platform_device *pdev) struct device_node *np; bool have_upstream_irq; u32 upstream_irq[2]; - int rc, channel; + int rc, channel, bank; int nr_addrs; u32 addrs[2]; @@ -575,6 +588,8 @@ static int aspeed_kcs_probe(struct platform_device *pdev) if (channel < 0) return channel; + bank = aspeed_kcs_of_get_bank(np); + nr_addrs = aspeed_kcs_of_get_io_address(pdev, addrs); if (nr_addrs < 0) return nr_addrs; @@ -590,9 +605,11 @@ static int aspeed_kcs_probe(struct platform_device *pdev) if (!priv) return -ENOMEM; + priv->channel = channel; + kcs_bmc = &priv->kcs_bmc; kcs_bmc->dev = &pdev->dev; - kcs_bmc->channel = channel; + kcs_bmc->channel = bank * KCS_CHANNEL_MAX + channel; kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1]; kcs_bmc->ops = &aspeed_kcs_ops; -- 2.34.1