From patchwork Wed Feb 8 02:41:22 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Brandt X-Patchwork-Id: 9561683 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 22DDE60547 for ; Wed, 8 Feb 2017 02:42:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1590628498 for ; Wed, 8 Feb 2017 02:42:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A18F2849A; Wed, 8 Feb 2017 02:42:40 +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 E8C8D28498 for ; Wed, 8 Feb 2017 02:42:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751567AbdBHCmi (ORCPT ); Tue, 7 Feb 2017 21:42:38 -0500 Received: from relmlor3.renesas.com ([210.160.252.173]:64630 "EHLO relmlie2.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751189AbdBHCmh (ORCPT ); Tue, 7 Feb 2017 21:42:37 -0500 Received: from unknown (HELO relmlir1.idc.renesas.com) ([10.200.68.151]) by relmlie2.idc.renesas.com with ESMTP; 08 Feb 2017 11:42:03 +0900 Received: from relmlac3.idc.renesas.com (relmlac3.idc.renesas.com [10.200.69.23]) by relmlir1.idc.renesas.com (Postfix) with ESMTP id 5FEF94F774; Wed, 8 Feb 2017 11:42:03 +0900 (JST) Received: by relmlac3.idc.renesas.com (Postfix, from userid 0) id 38BD218070; Wed, 8 Feb 2017 11:42:03 +0900 (JST) Received: from relmlac3.idc.renesas.com (localhost [127.0.0.1]) by relmlac3.idc.renesas.com (Postfix) with ESMTP id 3655918077; Wed, 8 Feb 2017 11:42:03 +0900 (JST) Received: from relmlii2.idc.renesas.com [10.200.68.66] by relmlac3.idc.renesas.com with ESMTP id MAA02795; Wed, 8 Feb 2017 11:42:03 +0900 X-IronPort-AV: E=Sophos;i="5.33,346,1477926000"; d="scan'208";a="233857964" Received: from unknown (HELO rtamta01.rta.renesas.com) ([143.103.48.75]) by relmlii2.idc.renesas.com with ESMTP; 08 Feb 2017 11:42:02 +0900 Received: from localhost.localdomain (unknown [143.103.58.102]) by rtamta01.rta.renesas.com (Postfix) with ESMTP id 399A12E9; Wed, 8 Feb 2017 02:41:56 +0000 (UTC) From: Chris Brandt To: Wolfram Sang Cc: linux-i2c@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Simon Horman , Geert Uytterhoeven , Chris Brandt Subject: [PATCH] i2c: riic: correctly finish transfers Date: Tue, 7 Feb 2017 21:41:22 -0500 Message-Id: <20170208024122.13116-1-chris.brandt@renesas.com> X-Mailer: git-send-email 2.10.1 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 This fixes the condition where the controller has not fully completed its final transfer and leaves the bus and controller in a undesirable state. At the end of the last transmitted byte, the existing driver would just signal for a STOP condition to be transmitted then immediately signal completion. However, the full STOP procedure might not have fully taken place by the time the runtime PM shuts off the peripheral clock, leaving the bus in a suspended state. Alternatively, the STOP condition on the bus may have completed, but when the next transaction is requested by the upper layer, not all the necessary register cleanup was finished from the last transfer which made the driver return BUS BUSY when it really wasn't. This patch now makes all transmit and receive transactions wait for the STOP condition to fully complete before signaling a completed transaction. With this new method, runtime PM no longer seems to be an issue. Fixes: 310c18a41450 ("i2c: riic: add driver") Signed-off-by: Chris Brandt Reviewed-by: Wolfram Sang --- drivers/i2c/busses/i2c-riic.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c index 6263ea8..8f11d34 100644 --- a/drivers/i2c/busses/i2c-riic.c +++ b/drivers/i2c/busses/i2c-riic.c @@ -80,6 +80,7 @@ #define ICIER_TEIE 0x40 #define ICIER_RIE 0x20 #define ICIER_NAKIE 0x10 +#define ICIER_SPIE 0x08 #define ICSR2_NACKF 0x10 @@ -216,11 +217,10 @@ static irqreturn_t riic_tend_isr(int irq, void *data) return IRQ_NONE; } - if (riic->is_last || riic->err) + if (riic->is_last || riic->err) { + riic_clear_set_bit(riic, 0, ICIER_SPIE, RIIC_ICIER); writeb(ICCR2_SP, riic->base + RIIC_ICCR2); - - writeb(0, riic->base + RIIC_ICIER); - complete(&riic->msg_done); + } return IRQ_HANDLED; } @@ -240,13 +240,13 @@ static irqreturn_t riic_rdrf_isr(int irq, void *data) if (riic->bytes_left == 1) { /* STOP must come before we set ACKBT! */ - if (riic->is_last) + if (riic->is_last) { + riic_clear_set_bit(riic, 0, ICIER_SPIE, RIIC_ICIER); writeb(ICCR2_SP, riic->base + RIIC_ICCR2); + } riic_clear_set_bit(riic, 0, ICMR3_ACKBT, RIIC_ICMR3); - writeb(0, riic->base + RIIC_ICIER); - complete(&riic->msg_done); } else { riic_clear_set_bit(riic, ICMR3_ACKBT, 0, RIIC_ICMR3); } @@ -259,6 +259,21 @@ static irqreturn_t riic_rdrf_isr(int irq, void *data) return IRQ_HANDLED; } +static irqreturn_t riic_stop_isr(int irq, void *data) +{ + struct riic_dev *riic = data; + + /* read back registers to confirm writes have fully propagated */ + writeb(0, riic->base + RIIC_ICSR2); + readb(riic->base + RIIC_ICSR2); + writeb(0, riic->base + RIIC_ICIER); + readb(riic->base + RIIC_ICIER); + + complete(&riic->msg_done); + + return IRQ_HANDLED; +} + static u32 riic_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; @@ -326,6 +341,7 @@ static struct riic_irq_desc riic_irqs[] = { { .res_num = 0, .isr = riic_tend_isr, .name = "riic-tend" }, { .res_num = 1, .isr = riic_rdrf_isr, .name = "riic-rdrf" }, { .res_num = 2, .isr = riic_tdre_isr, .name = "riic-tdre" }, + { .res_num = 3, .isr = riic_stop_isr, .name = "riic-stop" }, { .res_num = 5, .isr = riic_tend_isr, .name = "riic-nack" }, };