From patchwork Thu Oct 27 19:28:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiner Kallweit X-Patchwork-Id: 9400271 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 943A560588 for ; Thu, 27 Oct 2016 19:29:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 728B62A396 for ; Thu, 27 Oct 2016 19:29:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 676442A398; Thu, 27 Oct 2016 19:29:53 +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=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID 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 05AB82A396 for ; Thu, 27 Oct 2016 19:29:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489AbcJ0T3w (ORCPT ); Thu, 27 Oct 2016 15:29:52 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:36592 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753581AbcJ0T3w (ORCPT ); Thu, 27 Oct 2016 15:29:52 -0400 Received: by mail-wm0-f68.google.com with SMTP id c17so4174172wmc.3 for ; Thu, 27 Oct 2016 12:29:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:subject:to:references:cc:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=pPkCl9J9UcQffbhaRB9O/9P60lkl8Ng0nmHbYcgka7c=; b=UPl/10BnBb0o5X/ZhjtdbL8AFHjShrGUOIdPNB4cScIYVyvVubrtAt4fvpwZht3f0e j6NBEP9PcqVXFOtZN3A+zzAWxgXveqp570m5pUUpc6ZnLyAWzWO2Hi9WCxLWyFdLk9wP qeIt5QuXdA0kKZwbefGJ+XbZ+R6q4x3Bsa1QasER5TzJ2drc5eruD95yWXaEEfQAvCPH /YTtM7kwmZb/YJdBRczQAKgS7tr6hvwlcxTEy4eW8OyG5Eb6t+VQ/xOZYabaCbAlOuOC TV1671Fw+U2JdELzhu6018CqdrWnOtDEsaG+FY8fgpC+yf8nGuPKKxq7oEuOvE2n9EOf GWwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:subject:to:references:cc:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=pPkCl9J9UcQffbhaRB9O/9P60lkl8Ng0nmHbYcgka7c=; b=Q0QCn7N+/aZdXA9lN8ADIuKDSwRCTgXuWG8IHPMHlAOtEIl8PxyKIP4NlOXNYVumWk gWTQ+Y3V6q7Q+cvjCWLRaR/Y4TZl3Pb/6JwDizIsO+T+s7xSvqzF08g64JwZCkebA6ky obcoi898CjAld/dvJUyWKnyrA26Xm5g0Hp53pENqmL4Y58JD/JQv34HneAaS+SNjOw0m Etj7IcIB2Cfjf7zMtMoRNIwhtpVBRPnMlsNuxOg/ezjf/CGDnYZDuNWZT5eMwdS3ZlHz PQclNPzFh8mKA4SCPK4j6kTyQeJS5mlb4kEKLPq97W7DNh20AYnOo5QN1fekZIDkQPZH qKiw== X-Gm-Message-State: ABUngvdJdQq6xTNGea/pjNYNWsdzj4OdV7ZNpoyTNu5AYGp71VH1UC7ExfcI41nBtYRsoA== X-Received: by 10.194.250.1 with SMTP id yy1mr8066200wjc.219.1477596590447; Thu, 27 Oct 2016 12:29:50 -0700 (PDT) Received: from ?IPv6:2003:62:5f6e:ba00:49f8:f47b:2191:41c4? (p200300625F6EBA0049F8F47B219141C4.dip0.t-ipconnect.de. [2003:62:5f6e:ba00:49f8:f47b:2191:41c4]) by smtp.googlemail.com with ESMTPSA id a1sm10110381wjl.28.2016.10.27.12.29.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Oct 2016 12:29:50 -0700 (PDT) From: Heiner Kallweit Subject: [PATCH v2 08/09] spi: fsl-espi: add support for RXSKIP mode To: Mark Brown References: <5b98be38-17a2-79a2-14da-fb2bb6f8820f@gmail.com> Cc: "linux-spi@vger.kernel.org" Message-ID: <10553bf5-a1a7-5a5d-482b-8831f3ba859c@gmail.com> Date: Thu, 27 Oct 2016 21:28:51 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <5b98be38-17a2-79a2-14da-fb2bb6f8820f@gmail.com> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds support for ESPI RXSKIP mode. This mode is optimized for flash reads: - sends a number of bytes and then reads a number of bytes - shifts out zeros automatically when reading - optionally can be configured for dual read mode Signed-off-by: Heiner Kallweit --- v2: - rebased --- drivers/spi/spi-fsl-espi.c | 56 ++++++++++++++++++++++++++++++++++++++++++---- drivers/spi/spi-fsl-lib.h | 1 + 2 files changed, 53 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c index 2f95b19..e32dc30 100644 --- a/drivers/spi/spi-fsl-espi.c +++ b/drivers/spi/spi-fsl-espi.c @@ -150,7 +150,8 @@ static void fsl_espi_copy_to_buf(struct spi_message *m, list_for_each_entry(t, &m->transfers, transfer_list) { if (t->tx_buf) fsl_espi_memcpy_swab(buf, t->tx_buf, m, t); - else + /* In RXSKIP mode controller shifts zeros automatically */ + else if (!mspi->rxskip) memset(buf, 0, t->len); buf += t->len; } @@ -203,6 +204,42 @@ static int fsl_espi_check_message(struct spi_message *m) return 0; } +static void fsl_espi_check_rxskip_mode(struct spi_message *m, + struct mpc8xxx_spi *mspi) +{ + struct spi_transfer *t; + unsigned int i = 0, rxskip_len = 0; + + mspi->rxskip = 0; + + /* + * prerequisites for rxskip mode: + * - message has two transfers + * - first transfer is a write and second is a read + * + * In addition enable rxskip mode only if length of write transfer + * is <= FSL_ESPI_FIFO_SIZE. This allows to keep the current + * low-level transfer implementation. + * This constraint doesn't affect SPI NOR reads as typical use case + * for rxskip mode as the read command has only few bytes. + */ + list_for_each_entry(t, &m->transfers, transfer_list) { + if (i == 0) { + if (!t->tx_buf || t->rx_buf || + t->len > FSL_ESPI_FIFO_SIZE) + return; + rxskip_len = t->len; + } else if (i == 1) { + if (t->tx_buf || !t->rx_buf) + return; + } + i++; + } + + if (i == 2) + mspi->rxskip = rxskip_len; +} + static void fsl_espi_fill_tx_fifo(struct mpc8xxx_spi *mspi, u32 events) { u32 tx_fifo_avail; @@ -282,7 +319,7 @@ static void fsl_espi_setup_transfer(struct spi_device *spi, static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) { struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master); - u32 mask; + u32 mask, spcom; int ret; mpc8xxx_spi->rx_len = t->len; @@ -294,8 +331,18 @@ static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t) reinit_completion(&mpc8xxx_spi->done); /* Set SPCOM[CS] and SPCOM[TRANLEN] field */ - fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPCOM, - (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1))); + spcom = SPCOM_CS(spi->chip_select); + spcom |= SPCOM_TRANLEN(t->len - 1); + + /* configure RXSKIP mode */ + if (mpc8xxx_spi->rxskip) { + spcom |= SPCOM_RXSKIP(mpc8xxx_spi->rxskip); + mpc8xxx_spi->tx_len = mpc8xxx_spi->rxskip; + mpc8xxx_spi->rx_len = t->len - mpc8xxx_spi->rxskip; + mpc8xxx_spi->rx = t->rx_buf + mpc8xxx_spi->rxskip; + } + + fsl_espi_write_reg(mpc8xxx_spi, ESPI_SPCOM, spcom); /* enable interrupts */ mask = SPIM_DON; @@ -327,6 +374,7 @@ static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans) struct spi_device *spi = m->spi; int ret; + fsl_espi_check_rxskip_mode(m, mspi); fsl_espi_copy_to_buf(m, mspi); fsl_espi_setup_transfer(spi, trans); diff --git a/drivers/spi/spi-fsl-lib.h b/drivers/spi/spi-fsl-lib.h index 35a7a17..8096fae 100644 --- a/drivers/spi/spi-fsl-lib.h +++ b/drivers/spi/spi-fsl-lib.h @@ -32,6 +32,7 @@ struct mpc8xxx_spi { unsigned int rx_len; unsigned int tx_len; u8 *local_buf; + unsigned int rxskip; spinlock_t lock; #endif