From patchwork Fri Oct 30 06:53:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rayagonda Kokatanur X-Patchwork-Id: 11868605 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_TVD_MIME_NO_HEADERS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1CA9C00A89 for ; Fri, 30 Oct 2020 06:56:17 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D61122203 for ; Fri, 30 Oct 2020 06:56:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="z4Gy6OGV"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="EgiThpzm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4D61122203 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=broadcom.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type:MIME-Version: Cc:List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: References:In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uBlQ+iz9Y5MvnOrIuAeWa1fSNimqQP0zkev+ogtX6/Y=; b=z4Gy6OGVbWNx0h2LBVStgOIja XKJjFOgk1AQ1G1MQJuXRVxqERUopaU1bOKjTcXgZk4C60/p/ptTKQKW3I6Grc/kZVVhnu7WF/U1Eq Mj9jcfjr1YiJ2Bp/0jHsCrvZ0eWDluBMi6fu22hxa+PMWWOvAGkhl8Frp3qGRiMlmtqTsy6vmGSPN 03LYRqvOJRjudUYFPKAFux0EM+8NFfhQfKD1XyN0fDy79BECZRjTZtlLGJEXh93qQTZfGirbAwFM2 RQzhD3rD1wYLPnLepG97hBjLX9lQQ/47duy0DHQnyLfB0E+bU5iItCmIkxAk2Sum9xD3augGSyGtN KFYiDXalQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYOJD-0000kT-R7; Fri, 30 Oct 2020 06:54:47 +0000 Received: from mail-pg1-x542.google.com ([2607:f8b0:4864:20::542]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kYOIv-0000eg-8O for linux-arm-kernel@lists.infradead.org; Fri, 30 Oct 2020 06:54:31 +0000 Received: by mail-pg1-x542.google.com with SMTP id i7so2473269pgh.6 for ; Thu, 29 Oct 2020 23:54:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=4v+rccxgFbDh9J0Av9dhlm4mn7m7szaUzGMvUrk+XWI=; b=EgiThpzmDqrZAt8yaocWwVjH8GKCfdsub0lPNqHhKW+E5dcEnFSTTO0VWkNglt+7Lr zAsBKjGgPlXxUPvyQYbWdhIy5rG/WePPIDZaTqE3M5lQ+BAM1FOxY5RUqp2XK358ziSM 2106reUB/sR90zvikkiIqVlYgKzHWVOXsvB68= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=4v+rccxgFbDh9J0Av9dhlm4mn7m7szaUzGMvUrk+XWI=; b=siQ1xdrpqjzQ9OejNYxCJ9UQrUPKpYU5fJahhHX2ulA5tDIt+SCnvxEN61k2ZWkvHq ssP5HRr4MGbtuHer675TcV0V2PXyJ7zjQXTq9WBAzQAWqxavH+g0fdkS4vU+xDPKLnWR o0RO3+s87evhuDoD9lONt2szb0OH2LxoXf0cP5fCizSwksn9DF7gJfjG9Q1CULUn2b9D V6AKNoqKPaCu2WE2BSbq6chX+I7foa16aMWbE4cOHpViEWlYCWW74jKXndsOtcRLfOzO 71m2ocR0evbdN8FLr9GRgP6HhxcxQy3Yt4Kzp6Fln7H8t7An0a3UQbBAMu39HtUdyrzN B0sg== X-Gm-Message-State: AOAM530Wjgjn4HZQa+cjK18wMkutZ6cre2YXelEVpTKdMWp+eqICX979 cYZUrG7WXUm3bQUV2X30IXxrVA== X-Google-Smtp-Source: ABdhPJwrNfJRhvZnxGWm/DbUs97GQAMkF5JXyTG3+yfjlIvVv6cGs1tnb8ZU5EZZ1gEqY/Vbdb7VDA== X-Received: by 2002:a65:57ce:: with SMTP id q14mr939908pgr.55.1604040866806; Thu, 29 Oct 2020 23:54:26 -0700 (PDT) Received: from rayagonda.dhcp.broadcom.net ([192.19.234.250]) by smtp.gmail.com with ESMTPSA id n1sm4561547pgl.31.2020.10.29.23.54.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Oct 2020 23:54:26 -0700 (PDT) From: Rayagonda Kokatanur To: Ray Jui , Scott Branden , bcm-kernel-feedback-list@broadcom.com, Wolfram Sang , Florian Fainelli , Brendan Higgins , Andy Shevchenko , Lori Hikichi , Dhananjay Phadke , linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 5/6] i2c: iproc: handle master read request Date: Fri, 30 Oct 2020 12:23:38 +0530 Message-Id: <20201030065339.955-6-rayagonda.kokatanur@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201030065339.955-1-rayagonda.kokatanur@broadcom.com> References: <20201030065339.955-1-rayagonda.kokatanur@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201030_025429_485760_B4DBB197 X-CRM114-Status: GOOD ( 22.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rayagonda Kokatanur MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Handle single or multi byte master read request with or without repeated start. Fixes: c245d94ed106 ("i2c: iproc: Add multi byte read-write support for slave mode") Signed-off-by: Rayagonda Kokatanur --- drivers/i2c/busses/i2c-bcm-iproc.c | 215 +++++++++++++++++++++++------ 1 file changed, 170 insertions(+), 45 deletions(-) diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 7a235f9f5884..22e04055b447 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -160,6 +160,11 @@ #define IE_S_ALL_INTERRUPT_SHIFT 21 #define IE_S_ALL_INTERRUPT_MASK 0x3f +/* + * It takes ~18us to reading 10bytes of data, hence to keep tasklet + * running for less time, max slave read per tasklet is set to 10 bytes. + */ +#define MAX_SLAVE_RX_PER_INT 10 enum i2c_slave_read_status { I2C_SLAVE_RX_FIFO_EMPTY = 0, @@ -206,8 +211,18 @@ struct bcm_iproc_i2c_dev { /* bytes that have been read */ unsigned int rx_bytes; unsigned int thld_bytes; + + bool slave_rx_only; + bool rx_start_rcvd; + bool slave_read_complete; + u32 tx_underrun; + u32 slave_int_mask; + struct tasklet_struct slave_rx_tasklet; }; +/* tasklet to process slave rx data */ +static void slave_rx_tasklet_fn(unsigned long); + /* * Can be expanded in the future if more interrupt status bits are utilized */ @@ -261,6 +276,7 @@ static void bcm_iproc_i2c_slave_init( { u32 val; + iproc_i2c->tx_underrun = 0; if (need_reset) { /* put controller in reset */ val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET); @@ -297,8 +313,11 @@ static void bcm_iproc_i2c_slave_init( /* Enable interrupt register to indicate a valid byte in receive fifo */ val = BIT(IE_S_RX_EVENT_SHIFT); + /* Enable interrupt register to indicate a Master read transaction */ + val |= BIT(IE_S_RD_EVENT_SHIFT); /* Enable interrupt register for the Slave BUSY command */ val |= BIT(IE_S_START_BUSY_SHIFT); + iproc_i2c->slave_int_mask = val; iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); } @@ -324,76 +343,176 @@ static void bcm_iproc_i2c_check_slave_status( } } -static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, - u32 status) +static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c) { + u8 rx_data, rx_status; + u32 rx_bytes = 0; u32 val; - u8 value, rx_status; - /* Slave RX byte receive */ - if (status & BIT(IS_S_RX_EVENT_SHIFT)) { + while (rx_bytes < MAX_SLAVE_RX_PER_INT) { val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET); rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK; - if (rx_status == I2C_SLAVE_RX_START) { - /* Start of SMBUS for Master write */ - i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_WRITE_REQUESTED, &value); + rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK); - val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET); - value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK); + if (rx_status == I2C_SLAVE_RX_START) { + /* Start of SMBUS Master write */ i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_WRITE_RECEIVED, &value); - } else if (status & BIT(IS_S_RD_EVENT_SHIFT)) { - /* Start of SMBUS for Master Read */ + I2C_SLAVE_WRITE_REQUESTED, &rx_data); + iproc_i2c->rx_start_rcvd = true; + iproc_i2c->slave_read_complete = false; + } else if (rx_status == I2C_SLAVE_RX_DATA && + iproc_i2c->rx_start_rcvd) { + /* Middle of SMBUS Master write */ i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_READ_REQUESTED, &value); - iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); + I2C_SLAVE_WRITE_RECEIVED, &rx_data); + } else if (rx_status == I2C_SLAVE_RX_END && + iproc_i2c->rx_start_rcvd) { + /* End of SMBUS Master write */ + if (iproc_i2c->slave_rx_only) + i2c_slave_event(iproc_i2c->slave, + I2C_SLAVE_WRITE_RECEIVED, + &rx_data); + + i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, + &rx_data); + } else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) { + iproc_i2c->rx_start_rcvd = false; + iproc_i2c->slave_read_complete = true; + break; + } - val = BIT(S_CMD_START_BUSY_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); + rx_bytes++; + } +} - /* - * Enable interrupt for TX FIFO becomes empty and - * less than PKT_LENGTH bytes were output on the SMBUS - */ - val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); - val |= BIT(IE_S_TX_UNDERRUN_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); - } else { - /* Master write other than start */ - value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK); +static void slave_rx_tasklet_fn(unsigned long data) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data; + u32 int_clr; + + bcm_iproc_i2c_slave_read(iproc_i2c); + + /* clear pending IS_S_RX_EVENT_SHIFT interrupt */ + int_clr = BIT(IS_S_RX_EVENT_SHIFT); + + if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) { + /* + * In case of single byte master-read request, + * IS_S_TX_UNDERRUN_SHIFT event is generated before + * IS_S_START_BUSY_SHIFT event. Hence start slave data send + * from first IS_S_TX_UNDERRUN_SHIFT event. + * + * This means don't send any data from slave when + * IS_S_RD_EVENT_SHIFT event is generated else it will increment + * eeprom or other backend slave driver read pointer twice. + */ + iproc_i2c->tx_underrun = 0; + iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT); + + /* clear IS_S_RD_EVENT_SHIFT interrupt */ + int_clr |= BIT(IS_S_RD_EVENT_SHIFT); + } + + /* clear slave interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr); + /* enable slave interrupts */ + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask); +} + +static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c, + u32 status) +{ + u32 val; + u8 value; + + /* + * Slave events in case of master-write, master-write-read and, + * master-read + * + * Master-write : only IS_S_RX_EVENT_SHIFT event + * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT + * events + * Master-read : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT + * events or only IS_S_RD_EVENT_SHIFT + */ + if (status & BIT(IS_S_RX_EVENT_SHIFT) || + status & BIT(IS_S_RD_EVENT_SHIFT)) { + /* disable slave interrupts */ + val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); + val &= ~iproc_i2c->slave_int_mask; + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); + + if (status & BIT(IS_S_RD_EVENT_SHIFT)) + /* Master-write-read request */ + iproc_i2c->slave_rx_only = false; + else + /* Master-write request only */ + iproc_i2c->slave_rx_only = true; + + /* schedule tasklet to read data later */ + tasklet_schedule(&iproc_i2c->slave_rx_tasklet); + + /* clear only IS_S_RX_EVENT_SHIFT interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, + BIT(IS_S_RX_EVENT_SHIFT)); + } + + if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { + iproc_i2c->tx_underrun++; + if (iproc_i2c->tx_underrun == 1) + /* Start of SMBUS for Master Read */ i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_WRITE_RECEIVED, &value); - if (rx_status == I2C_SLAVE_RX_END) - i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_STOP, &value); - } - } else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) { - /* Master read other than start */ - i2c_slave_event(iproc_i2c->slave, - I2C_SLAVE_READ_PROCESSED, &value); + I2C_SLAVE_READ_REQUESTED, + &value); + else + /* Master read other than start */ + i2c_slave_event(iproc_i2c->slave, + I2C_SLAVE_READ_PROCESSED, + &value); iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value); + /* start transfer */ val = BIT(S_CMD_START_BUSY_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); + + /* clear interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, + BIT(IS_S_TX_UNDERRUN_SHIFT)); } - /* Stop */ + /* Stop received from master in case of master read transaction */ if (status & BIT(IS_S_START_BUSY_SHIFT)) { - i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); /* * Disable interrupt for TX FIFO becomes empty and * less than PKT_LENGTH bytes were output on the SMBUS */ - val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); - val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); - iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val); + iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, + iproc_i2c->slave_int_mask); + + /* End of SMBUS for Master Read */ + val = BIT(S_TX_WR_STATUS_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val); + + val = BIT(S_CMD_START_BUSY_SHIFT); + iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val); + + /* flush TX FIFOs */ + val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET); + val |= (BIT(S_FIFO_TX_FLUSH_SHIFT)); + iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val); + + i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value); + + /* clear interrupt */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, + BIT(IS_S_START_BUSY_SHIFT)); } - /* clear interrupt status */ - iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status); + /* check slave transmit status only if slave is transmitting */ + if (!iproc_i2c->slave_rx_only) + bcm_iproc_i2c_check_slave_status(iproc_i2c); - bcm_iproc_i2c_check_slave_status(iproc_i2c); return true; } @@ -1074,6 +1193,10 @@ static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave) return -EAFNOSUPPORT; iproc_i2c->slave = slave; + + tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn, + (unsigned long)iproc_i2c); + bcm_iproc_i2c_slave_init(iproc_i2c, false); return 0; } @@ -1094,6 +1217,8 @@ static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave) IE_S_ALL_INTERRUPT_SHIFT); iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp); + tasklet_kill(&iproc_i2c->slave_rx_tasklet); + /* Erase the slave address programmed */ tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET); tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);