From patchwork Sat Jan 18 11:58:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Federico Fuga X-Patchwork-Id: 1225133 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=studiofuga.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=studiofuga.com header.i=@studiofuga.com header.a=rsa-sha1 header.s=studiofuga.com header.b=Q0DFtLn9; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 480GgJ4Tslz9sRd for ; Sat, 18 Jan 2020 22:59:08 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728949AbgARL6r (ORCPT ); Sat, 18 Jan 2020 06:58:47 -0500 Received: from egyptian.birch.relay.mailchannels.net ([23.83.209.56]:51905 "EHLO egyptian.birch.relay.mailchannels.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727118AbgARL6r (ORCPT ); Sat, 18 Jan 2020 06:58:47 -0500 X-Sender-Id: dreamhost|x-authsender|fuga@studiofuga.com Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id 1B3275A0C3F; Sat, 18 Jan 2020 11:58:46 +0000 (UTC) Received: from pdx1-sub0-mail-a52.g.dreamhost.com (100-96-15-240.trex.outbound.svc.cluster.local [100.96.15.240]) (Authenticated sender: dreamhost) by relay.mailchannels.net (Postfix) with ESMTPA id 6CEF65A0F4F; Sat, 18 Jan 2020 11:58:45 +0000 (UTC) X-Sender-Id: dreamhost|x-authsender|fuga@studiofuga.com Received: from pdx1-sub0-mail-a52.g.dreamhost.com ([TEMPUNAVAIL]. [64.90.62.162]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384) by 0.0.0.0:2500 (trex/5.18.5); Sat, 18 Jan 2020 11:58:46 +0000 X-MC-Relay: Neutral X-MailChannels-SenderId: dreamhost|x-authsender|fuga@studiofuga.com X-MailChannels-Auth-Id: dreamhost X-Trouble-Unite: 177e267b4dcf2b01_1579348725877_4092681736 X-MC-Loop-Signature: 1579348725877:3218048286 X-MC-Ingress-Time: 1579348725876 Received: from pdx1-sub0-mail-a52.g.dreamhost.com (localhost [127.0.0.1]) by pdx1-sub0-mail-a52.g.dreamhost.com (Postfix) with ESMTP id 8CB51B0C3F; Sat, 18 Jan 2020 03:58:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=studiofuga.com; h=from:to :cc:subject:date:message-id; s=studiofuga.com; bh=oZe21OIXYOv92t t3O1BKTEcmdmY=; b=Q0DFtLn9LXzov6Ud+CxQoLRa1NOJ8Y0DysmQF/ACwhtXsx U9aTzIWTPNngSsvmkGZp8ptkN2pYsymRDlncmUFIB4YNmFR0bEoH2Sc9TmPRaFXO I7fyAB325Zffp3uZj0SiFd73TJeio7KX0yZut42wHL0kiUaT3/ADXOB7OeKXU= Received: from MintPad.studiofuga.local (unknown [5.102.6.226]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: fuga@studiofuga.com) by pdx1-sub0-mail-a52.g.dreamhost.com (Postfix) with ESMTPSA id C2796B0C42; Sat, 18 Jan 2020 03:58:40 -0800 (PST) X-DH-BACKEND: pdx1-sub0-mail-a52 From: Federico Fuga Cc: Federico Fuga , Gregory CLEMENT , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] i2c: mv64xxx: Implement I2C_M_RECV_LEN and I2C_FUNC_SMBUS_READ_BLOCK_DATA Date: Sat, 18 Jan 2020 12:58:20 +0100 Message-Id: <20200118115820.9080-1-fuga@studiofuga.com> X-Mailer: git-send-email 2.17.1 X-VR-OUT-STATUS: OK X-VR-OUT-SCORE: -55 X-VR-OUT-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedugedruddtgdeffecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucggtfgfnhhsuhgsshgtrhhisggvpdfftffgtefojffquffvnecuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenmhhishhsihhnghcuvffquchfihgvlhguucdlfedtmdenogetfedtuddqtdduucdludehmdenucfjughrpefhvffufffkofestddtredtredttdenucfhrhhomhephfgvuggvrhhitghoucfhuhhgrgcuoehfuhhgrgesshhtuhguihhofhhughgrrdgtohhmqeenucfkphephedruddtvddriedrvddvieenucfrrghrrghmpehmohguvgepshhmthhppdhhvghlohepofhinhhtrfgrugdrshhtuhguihhofhhughgrrdhlohgtrghlpdhinhgvthephedruddtvddriedrvddviedprhgvthhurhhnqdhprghthhephfgvuggvrhhitghoucfhuhhgrgcuoehfuhhgrgesshhtuhguihhofhhughgrrdgtohhmqedpmhgrihhlfhhrohhmpehfuhhgrgesshhtuhguihhofhhughgrrdgtohhmpdhnrhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpedt To: unlisted-recipients:; (no To-header on input) Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org The i2c_mv64xxx driver doesn't implement the I2C_M_REC_LEN function essential to allow blocks with variable length to be read from an i2c slave. This is needed to implement the SMBus Read Block Data function. This patch implements the function by changing the bytes_left and msg len on the fly if the flag is specified. It has been successfully tested on Allwinner A33 with a special i2c chip that returns variable length blocks on reading. Signed-off-by: Federico Fuga Acked-by: Gregory CLEMENT --- drivers/i2c/busses/i2c-mv64xxx.c | 67 +++++++++++++++++++++++++------- 1 file changed, 53 insertions(+), 14 deletions(-) diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index a5a95ea5b81a..cff9cb20bcc9 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -128,6 +128,7 @@ struct mv64xxx_i2c_data { u32 addr1; u32 addr2; u32 bytes_left; + u32 effective_length; u32 byte_posn; u32 send_stop; u32 block; @@ -333,7 +334,18 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) { drv_data->msg = drv_data->msgs; drv_data->byte_posn = 0; - drv_data->bytes_left = drv_data->msg->len; + + /* If we should retrieve the length from the buffer, make sure */ + /* to read enough bytes to avoid sending the */ + /* STOP bit after the read if the first byte */ + if (drv_data->msg->flags & I2C_M_RECV_LEN) { + drv_data->effective_length = -1; + drv_data->bytes_left = 3; + } else { + drv_data->effective_length = drv_data->msg->len; + drv_data->bytes_left = drv_data->msg->len; + } + drv_data->aborting = 0; drv_data->rc = 0; @@ -342,6 +354,42 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) drv_data->reg_base + drv_data->reg_offsets.control); } +static void +mv64xxx_i2c_do_send_stop(struct mv64xxx_i2c_data *drv_data) +{ + drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, + drv_data->reg_base + drv_data->reg_offsets.control); + drv_data->block = 0; + if (drv_data->errata_delay) + udelay(5); + + wake_up(&drv_data->waitq); +} + +static void +mv64xxx_i2c_do_read_data(struct mv64xxx_i2c_data *drv_data) +{ + u8 data; + + data = readl(drv_data->reg_base + drv_data->reg_offsets.data); + drv_data->msg->buf[drv_data->byte_posn++] = data; + + if (drv_data->effective_length == -1) { + /* length=0 should not be allowed, but is indeed possible. + * To avoid locking the chip, we keep reading at least 2 bytes + */ + if (data < 1) + data = 1; + drv_data->effective_length = data+1; + drv_data->bytes_left = data+1; + drv_data->msg->len = data+1; + } + + writel(drv_data->cntl_bits, + drv_data->reg_base + drv_data->reg_offsets.control); +} + static void mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) { @@ -392,23 +440,13 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) break; case MV64XXX_I2C_ACTION_RCV_DATA: - drv_data->msg->buf[drv_data->byte_posn++] = - readl(drv_data->reg_base + drv_data->reg_offsets.data); - writel(drv_data->cntl_bits, - drv_data->reg_base + drv_data->reg_offsets.control); + mv64xxx_i2c_do_read_data(drv_data); break; case MV64XXX_I2C_ACTION_RCV_DATA_STOP: drv_data->msg->buf[drv_data->byte_posn++] = readl(drv_data->reg_base + drv_data->reg_offsets.data); - drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN; - writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, - drv_data->reg_base + drv_data->reg_offsets.control); - drv_data->block = 0; - if (drv_data->errata_delay) - udelay(5); - - wake_up(&drv_data->waitq); + mv64xxx_i2c_do_send_stop(drv_data); break; case MV64XXX_I2C_ACTION_INVALID: @@ -706,7 +744,8 @@ mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data) static u32 mv64xxx_i2c_functionality(struct i2c_adapter *adap) { - return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL; + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_FUNC_SMBUS_EMUL; } static int