From patchwork Fri Nov 10 11:52:10 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 10053019 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1C15D6032D for ; Fri, 10 Nov 2017 11:52:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1BDAA29A2F for ; Fri, 10 Nov 2017 11:52:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 10A492B1BB; Fri, 10 Nov 2017 11:52:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE03929A2F for ; Fri, 10 Nov 2017 11:52:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752848AbdKJLwR (ORCPT ); Fri, 10 Nov 2017 06:52:17 -0500 Received: from sauhun.de ([88.99.104.3]:42362 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695AbdKJLwQ (ORCPT ); Fri, 10 Nov 2017 06:52:16 -0500 Received: from localhost (p54B33659.dip0.t-ipconnect.de [84.179.54.89]) by pokefinder.org (Postfix) with ESMTPSA id 60C6D2C3853; Fri, 10 Nov 2017 12:52:14 +0100 (CET) From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, Jacopo Mondi , Yoshihiro Shimoda , Wolfram Sang Subject: [PATCH] i2c: sh_mobile: send STOP according to datasheet Date: Fri, 10 Nov 2017 12:52:10 +0100 Message-Id: <20171110115210.21955-1-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.11.0 Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We initiate STOP (or REP_START) on the second last WAIT interrupt currently. This works fine but is not according to the datasheet which says to do it on the last WAIT interrupt. This also simplifies the code quite a lot, so let's do it. Signed-off-by: Wolfram Sang Reviewed-by: Niklas Söderlund Tested-by: Jacopo Mondi --- Jacopo: another one to test, pretty please. drivers/i2c/busses/i2c-sh_mobile.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 40a66d466c3c49..c904be631db302 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -40,21 +40,21 @@ /* BUS: S A8 ACK P(*) */ /* IRQ: DTE WAIT */ /* ICIC: */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 */ /* */ /* 1 byte transmit */ /* BUS: S A8 ACK D8(1) ACK P(*) */ /* IRQ: DTE WAIT WAIT */ /* ICIC: -DTE */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 D8(1) */ /* */ /* 2 byte transmit */ /* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */ /* IRQ: DTE WAIT WAIT WAIT */ /* ICIC: -DTE */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 D8(1) D8(2) */ /* */ /* 3 bytes or more, +---------+ gets repeated */ @@ -113,7 +113,6 @@ enum sh_mobile_i2c_op { OP_TX_FIRST, OP_TX, OP_TX_STOP, - OP_TX_STOP_DATA, OP_TX_TO_RX, OP_RX, OP_RX_STOP, @@ -319,10 +318,7 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, case OP_TX: /* write data */ iic_wr(pd, ICDR, data); break; - case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */ - iic_wr(pd, ICDR, data); - /* fallthrough */ - case OP_TX_STOP: /* issue a stop */ + case OP_TX_STOP: /* issue a stop (or rep_start) */ iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS : ICCR_ICE | ICCR_TRS | ICCR_BBSY); break; @@ -356,11 +352,6 @@ static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd) return pd->pos == -1; } -static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd) -{ - return pd->pos == pd->msg->len - 1; -} - static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd, unsigned char *buf) { @@ -378,20 +369,12 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd) unsigned char data; if (pd->pos == pd->msg->len) { - /* Send stop if we haven't yet (DMA case) */ - if (pd->send_stop && pd->stop_after_dma) - i2c_op(pd, OP_TX_STOP, 0); + i2c_op(pd, OP_TX_STOP, 0); return 1; } sh_mobile_i2c_get_data(pd, &data); - - if (sh_mobile_i2c_is_last_byte(pd)) - i2c_op(pd, OP_TX_STOP_DATA, data); - else if (sh_mobile_i2c_is_first_byte(pd)) - i2c_op(pd, OP_TX_FIRST, data); - else - i2c_op(pd, OP_TX, data); + i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, data); pd->pos++; return 0;