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[209.132.180.67]) by mx.google.com with ESMTP id v17si3509035eda.256.2019.10.18.02.42.16; Fri, 18 Oct 2019 02:42:40 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@broadcom.com header.s=google header.b=Ne2YZfOC; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=broadcom.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404635AbfJQF6f (ORCPT + 99 others); Thu, 17 Oct 2019 01:58:35 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:33675 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404249AbfJQF6f (ORCPT ); Thu, 17 Oct 2019 01:58:35 -0400 Received: by mail-lj1-f193.google.com with SMTP id a22so1193068ljd.0 for ; Wed, 16 Oct 2019 22:58:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HRtuv85RUpCy16P4QblPyyCpN6CMLh+xxluBWZ+uAEw=; b=Ne2YZfOC9UHlpsGGMLxTY6lV9RiUqe6Q+pN8CjN/aHcLEMRE0igx9I7P27lJx0w1X4 10QSrb7X6rOzwBvabaczQaa7BM1EZvcm7pqgvPaBOCknUHY4T13TKGRtbaOuANvzb9oC LRpPwVO+4zvgwlZl9A9G1wWX9UNXcXFhHMxX0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HRtuv85RUpCy16P4QblPyyCpN6CMLh+xxluBWZ+uAEw=; b=Fx+TUzEoZ05CGQRbw3lEaUV+KcQ7cdmegX05FFCxMULFMCrhVk8T+Yv7zmJxbYa0P5 n3R+Tok885qDew3aLFifeJZ9t+AUmK6IYUdmp4JMn34VMKTN9gaJrqUev9iNhUty3E9q YBCDwziCg4N3jR6tBFgNpldHHVxkaBtNCpVrDXRKPrS8jn6GzF8lq2ZBVQhCQipHVosk wwId8PqLEOAPL/jHlaq8jU+KehHGx+aelaUBO+Njaeyx3FexO7Pw1bARtVu3GIoewYWq cUtCd/StqTISPhLob+T6gxKwsmopCW+BdUOfaxPun32ySnVJUKxZeoyEzw48iRfZS3P0 p/3Q== X-Gm-Message-State: APjAAAWocM4xOG+lpaTJHnPZofZnlsFE1P1DNIeJK1Tcpgnb/sAVrFy/ OBl3cp6GZDWjQyG+YHJgwdKDV99zRWLEmA21zh4LDw== X-Received: by 2002:a2e:9e85:: with SMTP id f5mr1127345ljk.247.1571291912077; Wed, 16 Oct 2019 22:58:32 -0700 (PDT) MIME-Version: 1.0 References: <1569825869-30640-1-git-send-email-rayagonda.kokatanur@broadcom.com> In-Reply-To: From: Rayagonda Kokatanur Date: Thu, 17 Oct 2019 11:28:20 +0530 Message-ID: Subject: Re: [PATCH v2 1/1] i2c: iproc: Add i2c repeated start capability To: Ray Jui , Scott Branden , BCM Kernel Feedback , Wolfram Sang , Michael Cheng , Shreesha Rajashekar , Lori Hikichi , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linux Kernel Mailing List Cc: Icarus Chau , Ray Jui , Shivaraj Shetty Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Wolfram, Please review the patch and let me know if you still have any review comments. Best regards, Rayagonda On Thu, Oct 10, 2019 at 3:02 PM Rayagonda Kokatanur wrote: > > Hi Wolfram, > > Did you get a chance to review this patch. > > Best regards, > Rayagonda > > > On Mon, Sep 30, 2019 at 12:19 PM Rayagonda Kokatanur > wrote: > > > > From: Lori Hikichi > > > > Enable handling of i2c repeated start. The current code > > handles a multi msg i2c transfer as separate i2c bus > > transactions. This change will now handle this case > > using the i2c repeated start protocol. The number of msgs > > in a transfer is limited to two, and must be a write > > followed by a read. > > > > Signed-off-by: Lori Hikichi > > Signed-off-by: Rayagonda Kokatanur > > Signed-off-by: Icarus Chau > > Signed-off-by: Ray Jui > > Signed-off-by: Shivaraj Shetty > > --- > > changes from v1: > > - Address following review comments from Wolfarm Sang, > > Use i2c_8bit_addr_from_msg() api instead of decoding i2c_msg struct and > > remove check against number of i2c message as it will be taken care > > by core using quirks flags. > > > > drivers/i2c/busses/i2c-bcm-iproc.c | 63 ++++++++++++++++++++++++++++++-------- > > 1 file changed, 50 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c > > index d7fd76b..e478db7 100644 > > --- a/drivers/i2c/busses/i2c-bcm-iproc.c > > +++ b/drivers/i2c/busses/i2c-bcm-iproc.c > > @@ -81,6 +81,7 @@ > > #define M_CMD_PROTOCOL_MASK 0xf > > #define M_CMD_PROTOCOL_BLK_WR 0x7 > > #define M_CMD_PROTOCOL_BLK_RD 0x8 > > +#define M_CMD_PROTOCOL_PROCESS 0xa > > #define M_CMD_PEC_SHIFT 8 > > #define M_CMD_RD_CNT_SHIFT 0 > > #define M_CMD_RD_CNT_MASK 0xff > > @@ -675,13 +676,20 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c, > > return 0; > > } > > > > -static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, > > - struct i2c_msg *msg) > > +/* > > + * If 'process_call' is true, then this is a multi-msg transfer that requires > > + * a repeated start between the messages. > > + * More specifically, it must be a write (reg) followed by a read (data). > > + * The i2c quirks are set to enforce this rule. > > + */ > > +static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c, > > + struct i2c_msg *msgs, bool process_call) > > { > > int i; > > u8 addr; > > u32 val, tmp, val_intr_en; > > unsigned int tx_bytes; > > + struct i2c_msg *msg = &msgs[0]; > > > > /* check if bus is busy */ > > if (!!(iproc_i2c_rd_reg(iproc_i2c, > > @@ -707,14 +715,29 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, > > val = msg->buf[i]; > > > > /* mark the last byte */ > > - if (i == msg->len - 1) > > - val |= BIT(M_TX_WR_STATUS_SHIFT); > > + if (!process_call && (i == msg->len - 1)) > > + val |= 1 << M_TX_WR_STATUS_SHIFT; > > > > iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); > > } > > iproc_i2c->tx_bytes = tx_bytes; > > } > > > > + /* Process the read message if this is process call */ > > + if (process_call) { > > + msg++; > > + iproc_i2c->msg = msg; /* point to second msg */ > > + > > + /* > > + * The last byte to be sent out should be a slave > > + * address with read operation > > + */ > > + addr = i2c_8bit_addr_from_msg(msg); > > + /* mark it the last byte out */ > > + val = addr | (1 << M_TX_WR_STATUS_SHIFT); > > + iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val); > > + } > > + > > /* mark as incomplete before starting the transaction */ > > if (iproc_i2c->irq) > > reinit_completion(&iproc_i2c->done); > > @@ -733,7 +756,7 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, > > * underrun interrupt, which will be triggerred when the TX FIFO is > > * empty. When that happens we can then pump more data into the FIFO > > */ > > - if (!(msg->flags & I2C_M_RD) && > > + if (!process_call && !(msg->flags & I2C_M_RD) && > > msg->len > iproc_i2c->tx_bytes) > > val_intr_en |= BIT(IE_M_TX_UNDERRUN_SHIFT); > > > > @@ -743,6 +766,8 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, > > */ > > val = BIT(M_CMD_START_BUSY_SHIFT); > > if (msg->flags & I2C_M_RD) { > > + u32 protocol; > > + > > iproc_i2c->rx_bytes = 0; > > if (msg->len > M_RX_FIFO_MAX_THLD_VALUE) > > iproc_i2c->thld_bytes = M_RX_FIFO_THLD_VALUE; > > @@ -758,7 +783,10 @@ static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, > > /* enable the RX threshold interrupt */ > > val_intr_en |= BIT(IE_M_RX_THLD_SHIFT); > > > > - val |= (M_CMD_PROTOCOL_BLK_RD << M_CMD_PROTOCOL_SHIFT) | > > + protocol = process_call ? > > + M_CMD_PROTOCOL_PROCESS : M_CMD_PROTOCOL_BLK_RD; > > + > > + val |= (protocol << M_CMD_PROTOCOL_SHIFT) | > > (msg->len << M_CMD_RD_CNT_SHIFT); > > } else { > > val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); > > @@ -774,17 +802,24 @@ static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, > > struct i2c_msg msgs[], int num) > > { > > struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter); > > - int ret, i; > > + bool process_call = false; > > + int ret; > > > > - /* go through all messages */ > > - for (i = 0; i < num; i++) { > > - ret = bcm_iproc_i2c_xfer_single_msg(iproc_i2c, &msgs[i]); > > - if (ret) { > > - dev_dbg(iproc_i2c->device, "xfer failed\n"); > > - return ret; > > + if (num == 2) { > > + /* Repeated start, use process call */ > > + process_call = true; > > + if (msgs[1].flags & I2C_M_NOSTART) { > > + dev_err(iproc_i2c->device, "Invalid repeated start\n"); > > + return -EOPNOTSUPP; > > } > > } > > > > + ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call); > > + if (ret) { > > + dev_dbg(iproc_i2c->device, "xfer failed\n"); > > + return ret; > > + } > > + > > return num; > > } > > > > @@ -806,6 +841,8 @@ static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap) > > }; > > > > static struct i2c_adapter_quirks bcm_iproc_i2c_quirks = { > > + .flags = I2C_AQ_COMB_WRITE_THEN_READ, > > + .max_comb_1st_msg_len = M_TX_RX_FIFO_SIZE, > > .max_read_len = M_RX_MAX_READ_LEN, > > }; > > > > -- > > 1.9.1 > >