From patchwork Tue Nov 14 14:43:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jon Hunter X-Patchwork-Id: 837887 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-tegra-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ybqyH5Rj7z9s7m for ; Wed, 15 Nov 2017 01:43:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754590AbdKNOnu (ORCPT ); Tue, 14 Nov 2017 09:43:50 -0500 Received: from hqemgate15.nvidia.com ([216.228.121.64]:15547 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754161AbdKNOni (ORCPT ); Tue, 14 Nov 2017 09:43:38 -0500 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com id ; Tue, 14 Nov 2017 06:43:36 -0800 Received: from HQMAIL106.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 14 Nov 2017 06:43:37 -0800 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 14 Nov 2017 06:43:37 -0800 Received: from HQMAIL112.nvidia.com (172.18.146.18) by HQMAIL106.nvidia.com (172.18.146.12) with Microsoft SMTP Server (TLS) id 15.0.1293.2; Tue, 14 Nov 2017 14:43:37 +0000 Received: from HQMAIL108.nvidia.com (172.18.146.13) by HQMAIL112.nvidia.com (172.18.146.18) with Microsoft SMTP Server (TLS) id 15.0.1293.2; Tue, 14 Nov 2017 14:43:36 +0000 Received: from hqnvemgw02.nvidia.com (172.16.227.111) by HQMAIL108.nvidia.com (172.18.146.13) with Microsoft SMTP Server id 15.0.1293.2 via Frontend Transport; Tue, 14 Nov 2017 14:43:36 +0000 Received: from moonraker.nvidia.com (Not Verified[10.21.132.144]) by hqnvemgw02.nvidia.com with Trustwave SEG (v7, 5, 8, 10121) id ; Tue, 14 Nov 2017 06:43:35 -0800 From: Jon Hunter To: Lee Jones CC: , , "Brian Norris" , Shawn Nematbakhsh , Benson Leung , Jon Hunter Subject: [PATCH V2 2/2] mfd: cros ec: spi: Simplify delay handling between SPI messages Date: Tue, 14 Nov 2017 14:43:28 +0000 Message-ID: <1510670608-19594-2-git-send-email-jonathanh@nvidia.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1510670608-19594-1-git-send-email-jonathanh@nvidia.com> References: <1510670608-19594-1-git-send-email-jonathanh@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 Sender: linux-tegra-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org The EC SPI driver prevents SPI transfers being to rapidly by keeping track of the time the last transfer was issued via the 'last_transfer_ns' variable. Previously, if the 'last_transfer_ns' variable was zero, this indicated that no previous transfer had been sent and that no delay was needed. However, the EC SPI driver has been updated to always initialise the 'last_transfer_ns' variable during probe and therefore, it is no longer necessary to test if it is zero. Remove the code that checks if this variable is zero. Signed-off-by: Jon Hunter Reviewed-by: Brian Norris Reviewed-by: Douglas Anderson Acked-by: Benson Leung --- Changes since V1: - Added Brian's reviewed-by. drivers/mfd/cros_ec_spi.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index a14196e95e9b..7849d781c6bb 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -72,8 +72,7 @@ * struct cros_ec_spi - information about a SPI-connected EC * * @spi: SPI device we are connected to - * @last_transfer_ns: time that we last finished a transfer, or 0 if there - * if no record + * @last_transfer_ns: time that we last finished a transfer. * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that * is sent when we want to turn on CS at the start of a transaction. * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that @@ -378,18 +377,15 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, u8 *rx_buf; u8 sum; int ret = 0, final_ret; + unsigned long delay; len = cros_ec_prepare_tx(ec_dev, ec_msg); dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); /* If it's too soon to do another transaction, wait */ - if (ec_spi->last_transfer_ns) { - unsigned long delay; /* The delay completed so far */ - - delay = ktime_get_ns() - ec_spi->last_transfer_ns; - if (delay < EC_SPI_RECOVERY_TIME_NS) - ndelay(EC_SPI_RECOVERY_TIME_NS - delay); - } + delay = ktime_get_ns() - ec_spi->last_transfer_ns; + if (delay < EC_SPI_RECOVERY_TIME_NS) + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); rx_buf = kzalloc(len, GFP_KERNEL); if (!rx_buf) @@ -510,18 +506,15 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, u8 *rx_buf; int sum; int ret = 0, final_ret; + unsigned long delay; len = cros_ec_prepare_tx(ec_dev, ec_msg); dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); /* If it's too soon to do another transaction, wait */ - if (ec_spi->last_transfer_ns) { - unsigned long delay; /* The delay completed so far */ - - delay = ktime_get_ns() - ec_spi->last_transfer_ns; - if (delay < EC_SPI_RECOVERY_TIME_NS) - ndelay(EC_SPI_RECOVERY_TIME_NS - delay); - } + delay = ktime_get_ns() - ec_spi->last_transfer_ns; + if (delay < EC_SPI_RECOVERY_TIME_NS) + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); rx_buf = kzalloc(len, GFP_KERNEL); if (!rx_buf)