From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C31C3379C2C for ; Mon, 8 Jun 2026 05:43:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780897424; cv=none; b=b/h+gdS6yU2kjzAHhqNFwNSps4vAPHweUyjewBfI+pU1al3EVW+Z2RgTDyBcaMqEiMHdLTIC97WfK8qQkS1UsegKyAVKhH35N2LePxBrruYfK1+PRmhmPirfWMpAruJxGF1adX/xfv+fVjBfsfNjcuJiHlGRecUBNI1f2xbtNQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780897424; c=relaxed/simple; bh=7VHYV2bZu3Porwj0TuQLE+9A1Y+MGMUcHwFPdf21XE0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AWnpC+qduMFevZ1r0niAiOL69tXNJZc32Mj45SWVcMNw1xr9cG8S4jH3qf1qQuWn2i+shDrEDmkM40oP75N5sufAeIz+wwIgIEQnsFaZihxMw2tWSKX/DsmJ9gns24RlH+mjkM4okYdiRAyoPzmH8LuZ3+IDb/uBmXqas8G2rns= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=AhtIYN92; arc=none smtp.client-ip=198.175.65.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="AhtIYN92" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780897422; x=1812433422; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7VHYV2bZu3Porwj0TuQLE+9A1Y+MGMUcHwFPdf21XE0=; b=AhtIYN92yU8g5KKcbQlnkKK9SrynayyTE0Q9l8NmSqjHgUI302Jed/KU 7iV1a9Fddg+C6FdgJTQ9gEM7Vzi5nvSz2rTK2fLdcUVSAuExdm3ZC5omM I6F320n7eP2rHnu0ciT4j9bjSdL/yjHRWTx3C7ETbfk9LzPjTZ6KobZ8h ZU04/Rup2kIoylbXCbPSFcHFttVu0OTmOznLUMYpT/TiobfaMP6cPwkRT eZcinrlAGxllxFlAx/VLlDL9YicXa1IXk/lNZPpi8XFhocvSdgG+MXthK XnN6pbSfqpTjNkb180i0fsYGAL1y0E8LENOJZGN1ZeATDQvDnqyvidq4Y g==; X-CSE-ConnectionGUID: QcC2jmXoTM2MgUZaXI7efg== X-CSE-MsgGUID: qXgeGzd2R4meV5QrCElb+w== X-IronPort-AV: E=McAfee;i="6800,10657,11810"; a="104284070" X-IronPort-AV: E=Sophos;i="6.24,193,1774335600"; d="scan'208";a="104284070" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2026 22:43:42 -0700 X-CSE-ConnectionGUID: zM6OP8QdR1KSt6QVBGSCzg== X-CSE-MsgGUID: clC6zJTcQbyEJZVhCoFneA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,193,1774335600"; d="scan'208";a="245505708" Received: from conormcd-mobl2.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.114]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2026 22:43:39 -0700 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, david.nystrom@est.tech, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V3 8/8] i3c: mipi-i3c-hci: Add Hot-Join support Date: Mon, 8 Jun 2026 08:43:12 +0300 Message-ID: <20260608054312.10604-9-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260608054312.10604-1-adrian.hunter@intel.com> References: <20260608054312.10604-1-adrian.hunter@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Content-Transfer-Encoding: 8bit Wire the MIPI I3C HCI driver into the I3C core Hot-Join framework to allow targets to dynamically join the bus after initial DAA. HCI hardware ACKs or NACKs Hot-Join requests based on HC_CONTROL.HOT_JOIN_CTRL. This was previously left in the NACK-and-DISEC state, effectively preventing Hot-Join. Implement the ->enable_hotjoin() and ->disable_hotjoin() master operations so the core and user space can control this policy at runtime. Also issue broadcast ENEC HJ when enabling Hot-Join. This is required because the controller may have previously DISEC'ed the Hot-Join event, causing targets that were NACKed once to never retry. Acknowledged Hot-Join requests are delivered as IBIs on the reserved address 0x02. Update both the DMA and PIO IBI paths to recognise this address and forward the event to i3c_master_queue_hotjoin(). To make Hot-Join usable by default, enable it once after the initial DAA. This is gated by rpm_ibi_allowed, since otherwise keeping Hot-Join enabled prevents runtime suspend. A new hj_init_done flag ensures this one-time enablement is not repeated on subsequent DAAs. Signed-off-by: Adrian Hunter Reviewed-by: Frank Li --- Changes in V3: None Changes in V2: Add Frank's Rev'd by drivers/i3c/master/mipi-i3c-hci/core.c | 50 ++++++++++++++++++++++++-- drivers/i3c/master/mipi-i3c-hci/dma.c | 5 +++ drivers/i3c/master/mipi-i3c-hci/hci.h | 1 + drivers/i3c/master/mipi-i3c-hci/pio.c | 5 +++ 4 files changed, 58 insertions(+), 3 deletions(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index c6edbbedfdd7..53797841b63f 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -392,11 +392,52 @@ static int i3c_hci_send_ccc_cmd(struct i3c_master_controller *m, return ret; } +static int i3c_hci_enable_hotjoin(struct i3c_master_controller *m) +{ + struct i3c_hci *hci = to_i3c_hci(m); + int ret; + + reg_clear(HC_CONTROL, HC_CONTROL_HOT_JOIN_CTRL); + + /* + * Broadcast Hot_join enable, so that an I3C device that has previously + * had its Hot-Join request NACK'ed knows to try again. + */ + ret = i3c_master_enec_disec_locked(m, I3C_BROADCAST_ADDR, true, I3C_CCC_EVENT_HJ, true); + if (ret) { + reg_set(HC_CONTROL, HC_CONTROL_HOT_JOIN_CTRL); + dev_err(&hci->master.dev, "Hot-Join ENEC CCC failed\n"); + } + + return ret; +} + +static int i3c_hci_disable_hotjoin(struct i3c_master_controller *m) +{ + struct i3c_hci *hci = to_i3c_hci(m); + + reg_set(HC_CONTROL, HC_CONTROL_HOT_JOIN_CTRL); + return 0; +} + static int i3c_hci_daa(struct i3c_master_controller *m) { struct i3c_hci *hci = to_i3c_hci(m); + int ret; - return hci->cmd->perform_daa(hci); + ret = hci->cmd->perform_daa(hci); + + if (!hci->hj_init_done) { + hci->hj_init_done = true; + /* + * Enable Hot-Join by default after initial DAA if it does not + * prevent runtime suspend. + */ + if (m->rpm_ibi_allowed && !ret) + m->hotjoin = !i3c_hci_enable_hotjoin(m); + } + + return ret; } static int i3c_hci_i3c_xfers(struct i3c_dev_desc *dev, @@ -652,6 +693,8 @@ static const struct i3c_master_controller_ops i3c_hci_ops = { .enable_ibi = i3c_hci_enable_ibi, .disable_ibi = i3c_hci_disable_ibi, .recycle_ibi_slot = i3c_hci_recycle_ibi_slot, + .enable_hotjoin = i3c_hci_enable_hotjoin, + .disable_hotjoin = i3c_hci_disable_hotjoin, }; static irqreturn_t i3c_hci_irq_handler(int irq, void *dev_id) @@ -833,8 +876,9 @@ static int i3c_hci_do_reset_and_restore(struct i3c_hci *hci) scoped_guard(spinlock_irqsave, &hci->lock) hci->irq_inactive = false; - /* Enable bus with Hot-Join disabled */ - reg_set(HC_CONTROL, HC_CONTROL_BUS_ENABLE | HC_CONTROL_HOT_JOIN_CTRL); + /* Enable bus, restoring hot-join state */ + reg_set(HC_CONTROL, + HC_CONTROL_BUS_ENABLE | (hci->master.hotjoin ? 0 : HC_CONTROL_HOT_JOIN_CTRL)); return 0; } diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 5c6ae2055618..87622d6f817e 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -960,6 +960,11 @@ static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh) } /* determine who this is for */ + if (ibi_addr == I3C_HOT_JOIN_ADDR) { + i3c_master_queue_hotjoin(&hci->master); + goto done; + } + dev = i3c_hci_addr_to_dev(hci, ibi_addr); if (!dev) { dev_err(&hci->master.dev, diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index 30297823ca85..41d31a53abd3 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -57,6 +57,7 @@ struct i3c_hci { bool irq_inactive; bool enqueue_blocked; bool recovery_needed; + bool hj_init_done; wait_queue_head_t enqueue_wait_queue; u32 caps; unsigned int quirks; diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c index 6b8cc5f2b4d2..b5ae1cfaa9e0 100644 --- a/drivers/i3c/master/mipi-i3c-hci/pio.c +++ b/drivers/i3c/master/mipi-i3c-hci/pio.c @@ -862,6 +862,11 @@ static bool hci_pio_prep_new_ibi(struct i3c_hci *hci, struct hci_pio_data *pio) ibi->seg_len = FIELD_GET(IBI_DATA_LENGTH, ibi_status); ibi->seg_cnt = ibi->seg_len; + if (ibi->addr == I3C_HOT_JOIN_ADDR) { + i3c_master_queue_hotjoin(&hci->master); + return true; + } + dev = i3c_hci_addr_to_dev(hci, ibi->addr); if (!dev) { dev_err(&hci->master.dev, -- 2.51.0