From patchwork Mon Mar 5 15:36:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Shych X-Patchwork-Id: 881496 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) 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=fail (p=none dis=none) header.from=mellanox.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zw1HF0T7gz9sZZ for ; Tue, 6 Mar 2018 00:39:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934028AbeCENju (ORCPT ); Mon, 5 Mar 2018 08:39:50 -0500 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:51676 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935223AbeCENjr (ORCPT ); Mon, 5 Mar 2018 08:39:47 -0500 Received: from Internal Mail-Server by MTLPINE1 (envelope-from michaelsh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 5 Mar 2018 15:40:10 +0200 Received: from r-mgtswh-226.mtr.labs.mlnx. (r-mgtswh-226.mtr.labs.mlnx [10.209.1.51]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id w25DdfL0005948; Mon, 5 Mar 2018 15:39:43 +0200 From: michaelsh@mellanox.com To: wsa@the-dreams.de Cc: linux-i2c@vger.kernel.org, Michael Shych Subject: [PATCH v1 2/5] i2c: busses: Add support for smbus block read transaction Date: Mon, 5 Mar 2018 15:36:01 +0000 Message-Id: <1520264164-168110-3-git-send-email-michaelsh@mellanox.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1520264164-168110-1-git-send-email-michaelsh@mellanox.com> References: <1520264164-168110-1-git-send-email-michaelsh@mellanox.com> Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Michael Shych It adds support for smbus block read transaction. CPLD smbus block read bit of capability register is verified during driver initialization, and driver data is updated if such capability is available. In case an upper layer requests a read transaction of length one and expects that length will be the first received byte, driver will notify CPLD about SMBus block read transaction flavor, so CPLD will know to execute such kind of transaction. Signed-off-by: Michael Shych --- drivers/i2c/busses/i2c-mlxcpld.c | 38 ++++++++++++++++++++++++++++++++------ 1 file changed, 32 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-mlxcpld.c b/drivers/i2c/busses/i2c-mlxcpld.c index 6434f8c..4d8efe0 100644 --- a/drivers/i2c/busses/i2c-mlxcpld.c +++ b/drivers/i2c/busses/i2c-mlxcpld.c @@ -47,6 +47,7 @@ #define MLXCPLD_I2C_DATA_REG_SZ 36 #define MLXCPLD_I2C_DATA_SZ_BIT BIT(5) #define MLXCPLD_I2C_DATA_SZ_MASK GENMASK(6, 5) +#define MLXCPLD_I2C_SMBUS_BLK_BIT BIT(7) #define MLXCPLD_I2C_MAX_ADDR_LEN 4 #define MLXCPLD_I2C_RETR_NUM 2 #define MLXCPLD_I2C_XFER_TO 500000 /* usec */ @@ -85,6 +86,7 @@ struct mlxcpld_i2c_priv { struct mutex lock; struct mlxcpld_i2c_curr_xfer xfer; struct device *dev; + bool smbus_block; }; static void mlxcpld_i2c_lpc_write_buf(u8 *data, u8 len, u32 addr) @@ -297,7 +299,7 @@ static int mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv *priv) static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv) { int status, i, timeout = 0; - u8 datalen; + u8 datalen, val; do { usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME); @@ -326,9 +328,22 @@ static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv) * Actual read data len will be always the same as * requested len. 0xff (line pull-up) will be returned * if slave has no data to return. Thus don't read - * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD. + * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD. Only in case of + * SMBus block read transaction data len can be different, + * check this case. */ - datalen = priv->xfer.data_len; + mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG, &val, + 1); + if (priv->smbus_block && (val & MLXCPLD_I2C_SMBUS_BLK_BIT)) { + mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG, + &datalen, 1); + if (unlikely(datalen > (I2C_SMBUS_BLOCK_MAX + 1))) { + dev_err(priv->dev, "Incorrect smbus block read message len\n"); + return -E2BIG; + } + } else { + datalen = priv->xfer.data_len; + } mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_DATA_REG, priv->xfer.msg[i].buf, datalen); @@ -346,12 +361,20 @@ static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv) static void mlxcpld_i2c_xfer_msg(struct mlxcpld_i2c_priv *priv) { int i, len = 0; - u8 cmd; + u8 cmd, val; mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG, &priv->xfer.data_len, 1); - mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG, - &priv->xfer.addr_width, 1); + + val = priv->xfer.addr_width; + /* Notify HW about SMBus block read transaction */ + if (priv->smbus_block && priv->xfer.msg_num >= 2 && + priv->xfer.msg[1].len == 1 && + (priv->xfer.msg[1].flags & I2C_M_RECV_LEN) && + (priv->xfer.msg[1].flags & I2C_M_RD)) + val |= MLXCPLD_I2C_SMBUS_BLK_BIT; + + mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG, &val, 1); for (i = 0; i < priv->xfer.msg_num; i++) { if ((priv->xfer.msg[i].flags & I2C_M_RD) != I2C_M_RD) { @@ -481,6 +504,9 @@ static int mlxcpld_i2c_probe(struct platform_device *pdev) /* Check support for extended transaction length */ if ((val & MLXCPLD_I2C_DATA_SZ_MASK) == MLXCPLD_I2C_DATA_SZ_BIT) mlxcpld_i2c_adapter.quirks = &mlxcpld_i2c_quirks_ext; + /* Check support for smbus block transaction */ + if (val & MLXCPLD_I2C_SMBUS_BLK_BIT) + priv->smbus_block = true; priv->adap = mlxcpld_i2c_adapter; priv->adap.dev.parent = &pdev->dev; priv->base_addr = MLXPLAT_CPLD_LPC_I2C_BASE_ADDR;