From patchwork Tue Apr 5 10:07:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 12801460 X-Patchwork-Delegate: geert@linux-m68k.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EEFBC4332F for ; Tue, 5 Apr 2022 11:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344052AbiDELuU (ORCPT ); Tue, 5 Apr 2022 07:50:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356237AbiDEKXb (ORCPT ); Tue, 5 Apr 2022 06:23:31 -0400 Received: from mail.zeus03.de (www.zeus03.de [194.117.254.33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4ABC0BABA6 for ; Tue, 5 Apr 2022 03:08:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=sang-engineering.com; h= from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; s=k1; bh=OrW2E1pcDjKZoQF/AXmdHvsNIYk ywXHAVyE1xLW/o1A=; b=Jd7y+V0D9OVOj3rQdTMqpfyI1b6FVWXR9HqjoujfePm niD5dfwl4f9v3h7mRVWjuoFq3RAgfh6EulSZTxitNAhSN3oKTavu3NwwJzo+46lI 5Abt9rQiPi0Jdg4T8sVzeuL+E+57m5dJDdCxpa/azIkWxSLYVs+K2ZkLVLXM1KrY = Received: (qmail 2245954 invoked from network); 5 Apr 2022 12:08:00 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 5 Apr 2022 12:08:00 +0200 X-UD-Smtp-Session: l3s3148p1@FKp1a+XbRrggAQnoAHlrADXnfPIF6sP/ From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Eugeniu Rosca , Wolfram Sang , Bhuvanesh Surachari , Andrew Gabbasov Subject: [PATCH v4] i2c: rcar: add support for I2C_M_RECV_LEN Date: Tue, 5 Apr 2022 12:07:56 +0200 Message-Id: <20220405100756.42920-1-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org With this feature added, SMBus Block reads and Proc calls are now supported. This patch is the best of two independent developments by Wolfram and Bhuvanesh + Andrew, refactored again by Wolfram. Signed-off-by: Bhuvanesh Surachari Signed-off-by: Andrew Gabbasov Signed-off-by: Wolfram Sang Reviewed-by: Eugeniu Rosca Tested-by: Eugeniu Rosca --- For testing, I wired a Lager board (R-Car H2) and a Salvator-XS (R-Car H3 ES2.0) together. The Lager board ran the testunit and provided SMBus Proc Calls. The Salvator-XS board was requesting the data. Compared to my previous version: sending 1 byte works now, sending with DMA as well. Invalid sizes are detected, too. This is as much as I can test, I'd think. Compared to Bhuvanesh + Andrew's last version: less intrusive and more self contained (no goto), Proc Calls are covered as well I tried some other refactoring as well (like one single place where rcar_i2c_dma() is called) but IMHO this is the most readable solution. Thank you everyone for working on this. I am very interested in your comments and test results! drivers/i2c/busses/i2c-rcar.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index f71c730f9838..f45991252993 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -105,6 +105,7 @@ #define ID_DONE (1 << 2) #define ID_ARBLOST (1 << 3) #define ID_NACK (1 << 4) +#define ID_EPROTO (1 << 5) /* persistent flags */ #define ID_P_HOST_NOTIFY BIT(28) #define ID_P_REP_AFTER_RD BIT(29) @@ -522,6 +523,7 @@ static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) { struct i2c_msg *msg = priv->msg; + bool recv_len_init = priv->pos == 0 && msg->flags & I2C_M_RECV_LEN; /* FIXME: sometimes, unknown interrupt happened. Do nothing */ if (!(msr & MDR)) @@ -535,12 +537,29 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) rcar_i2c_dma(priv); } else if (priv->pos < msg->len) { /* get received data */ - msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX); + u8 data = rcar_i2c_read(priv, ICRXTX); + + msg->buf[priv->pos] = data; + if (recv_len_init) { + if (data == 0 || data > I2C_SMBUS_BLOCK_MAX) { + priv->flags |= ID_DONE | ID_EPROTO; + return; + } + msg->len += msg->buf[0]; + /* Enough data for DMA? */ + if (rcar_i2c_dma(priv)) + return; + /* new length after RECV_LEN now properly initialized */ + recv_len_init = false; + } priv->pos++; } - /* If next received data is the _LAST_, go to new phase. */ - if (priv->pos + 1 == msg->len) { + /* + * If next received data is the _LAST_ and we are not waiting for a new + * length because of RECV_LEN, then go to a new phase. + */ + if (priv->pos + 1 == msg->len && !recv_len_init) { if (priv->flags & ID_LAST_MSG) { rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); } else { @@ -847,6 +866,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, ret = -ENXIO; } else if (priv->flags & ID_ARBLOST) { ret = -EAGAIN; + } else if (priv->flags & ID_EPROTO) { + ret = -EPROTO; } else { ret = num - priv->msgs_left; /* The number of transfer */ } @@ -909,6 +930,8 @@ static int rcar_i2c_master_xfer_atomic(struct i2c_adapter *adap, ret = -ENXIO; } else if (priv->flags & ID_ARBLOST) { ret = -EAGAIN; + } else if (priv->flags & ID_EPROTO) { + ret = -EPROTO; } else { ret = num - priv->msgs_left; /* The number of transfer */ } @@ -975,7 +998,7 @@ static u32 rcar_i2c_func(struct i2c_adapter *adap) * I2C_M_IGNORE_NAK (automatically sends STOP after NAK) */ u32 func = I2C_FUNC_I2C | I2C_FUNC_SLAVE | - (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); + (I2C_FUNC_SMBUS_EMUL_ALL & ~I2C_FUNC_SMBUS_QUICK); if (priv->flags & ID_P_HOST_NOTIFY) func |= I2C_FUNC_SMBUS_HOST_NOTIFY;