From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 20C32C433E1 for ; Mon, 18 May 2020 11:09:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F0A4E2070A for ; Mon, 18 May 2020 11:09:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="K4yu4oVs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727123AbgERLJt (ORCPT ); Mon, 18 May 2020 07:09:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726428AbgERLJs (ORCPT ); Mon, 18 May 2020 07:09:48 -0400 Received: from mail-pl1-x641.google.com (mail-pl1-x641.google.com [IPv6:2607:f8b0:4864:20::641]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A8219C05BD09; Mon, 18 May 2020 04:09:48 -0700 (PDT) Received: by mail-pl1-x641.google.com with SMTP id t7so4105352plr.0; Mon, 18 May 2020 04:09:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=z0K0/5OzzViPZMz8dEGdWi2fs5WJcxW5HTeiBCJAzcg=; b=K4yu4oVsBUAvUVFewNEyHdUY5TBIs/1+QblQu5oIUbAg3rw1Eh9zW0Rm64Hkv5BX/2 Cl0m3VOfl4AJojsx0o8gSJQ8XSC53BaoiHqcLhCLX6x5AdScum6jYOvNbZirieoVlMfn DCCwkqoULLl0Def4J32uJu/sB97pnJq8PsvnamZXrHXQX4Mkdb6QguKIMYzehOAvO6Jf TizH3AxhYv06FKMgUpsC9t5T3US4xWGDBaM27bGfaJt61AR7znME3x1nc1DJRGSJI6iG n25HPv62AqkKhHUZLEaCH5aGFcj9cysGKRnUROpvGzrnPeZWhFOxIBFvlb+3XudjEin8 oMZg== 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=z0K0/5OzzViPZMz8dEGdWi2fs5WJcxW5HTeiBCJAzcg=; b=fwF8PjimJ8BO4XV0ZchWvrBqShFCFFt74BWPMvNcljXJnGFwMMwQJu/1f1Dnmd51HG CPjyMQD9ikYzS5Rr67H8g12R3IXmN0RreYi8LqER1b71thp7xou9xxJDrQEyxYj5T67K E3cHszqB8xqhGVulY7LEy+v/uW54RGyEydyozNvp0mM7PB65h8M7rqMJXAw+g3QvavvK Dizd+OiY3sKzKfPsvbTOpMq0gINxQxVpOKg3fD6Vew176p2mmxuZVDrx56u9NLGkRhUf eTSIWMIEHIAsyvaP0U4uiCA8bhvwQ5HF1AxBqDR6iKQ50/vsF2Ukp6XD26mbI2w+7k+3 o4tw== X-Gm-Message-State: AOAM53344IL+TGbDmO/BbzS5axw5fK8ZYZ8h3HALxajZCHu6HOS8mhn/ BgKNOVO1hqBpyhxGRtIoTsc= X-Google-Smtp-Source: ABdhPJyWWs1JYZRi/j45YsKeOBSSYfAuy0RjZQll8EZvS/1kzTOj1iRG54tfK5bmmQSr5ewXc691vw== X-Received: by 2002:a17:902:9b8e:: with SMTP id y14mr15833614plp.109.1589800188239; Mon, 18 May 2020 04:09:48 -0700 (PDT) Received: from fmin-OptiPlex-7060.nreal.work ([103.206.190.146]) by smtp.gmail.com with ESMTPSA id a15sm8290630pju.3.2020.05.18.04.09.43 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 May 2020 04:09:47 -0700 (PDT) From: dillon.minfei@gmail.com To: robh+dt@kernel.org, p.zabel@pengutronix.de, mcoquelin.stm32@gmail.com, broonie@kernel.org, devicetree@vger.kernel.org, alexandre.torgue@st.com, thierry.reding@gmail.com, sam@ravnborg.org, airlied@linux.ie, daniel@ffwll.ch, mturquette@baylibre.com, sboyd@kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, dri-devel@lists.freedesktop.org, linux-clk@vger.kernel.org, dillon min Subject: [PATCH v4 3/8] spi: stm32: Add 'SPI_SIMPLEX_RX', 'SPI_3WIRE_RX' support for stm32f4 Date: Mon, 18 May 2020 19:09:20 +0800 Message-Id: <1589800165-3271-4-git-send-email-dillon.minfei@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1589800165-3271-1-git-send-email-dillon.minfei@gmail.com> References: <1589800165-3271-1-git-send-email-dillon.minfei@gmail.com> Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org From: dillon min in l3gd20 driver startup, there is a setup failed error return from stm32 spi driver " [ 2.687630] st-gyro-spi spi0.0: supply vdd not found, using dummy regulator [ 2.696869] st-gyro-spi spi0.0: supply vddio not found, using dummy regulator [ 2.706707] spi_stm32 40015000.spi: SPI transfer setup failed [ 2.713741] st-gyro-spi spi0.0: SPI transfer failed: -22 [ 2.721096] spi_master spi0: failed to transfer one message from queue [ 2.729268] iio iio:device0: failed to read Who-Am-I register. [ 2.737504] st-gyro-spi: probe of spi0.0 failed with error -22 " after debug into spi-stm32 driver, st-gyro-spi split two steps to read l3gd20 id first: send command to l3gd20 with read id command in tx_buf, rx_buf is null. second: read id with tx_buf is null, rx_buf not null. so, for second step, stm32 driver recongise this process is 'SPI_SIMPLE_RX' from stm32_spi_communication_type(), but there is no related process for this type in stm32f4_spi_set_mode(), then we get error from stm32_spi_transfer_one_setup(). we can use two method to fix this bug. 1, use stm32 spi's "In unidirectional receive-only mode (BIDIMODE=0 and RXONLY=1)". but as our code running in sdram, the read latency is too large to get so many receive overrun error in interrupts handler. 2, use stm32 spi's "In full-duplex (BIDIMODE=0 and RXONLY=0)", as tx_buf is null, we must add dummy data sent out before read data. so, add stm32f4_spi_tx_dummy() to handle this situation. Signed-off-by: dillon min --- drivers/spi/spi-stm32.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 44ac6eb3..72d9387 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -388,6 +388,14 @@ static int stm32h7_spi_get_fifo_size(struct stm32_spi *spi) return count; } +static void stm32f4_spi_tx_dummy(struct stm32_spi *spi) +{ + if (spi->cur_bpw == 16) + writew_relaxed(0x5555, spi->base + STM32F4_SPI_DR); + else + writeb_relaxed(0x55, spi->base + STM32F4_SPI_DR); +} + /** * stm32f4_spi_get_bpw_mask - Return bits per word mask * @spi: pointer to the spi controller data structure @@ -811,7 +819,9 @@ static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id) mask |= STM32F4_SPI_SR_TXE; } - if (!spi->cur_usedma && spi->cur_comm == SPI_FULL_DUPLEX) { + if (!spi->cur_usedma && (spi->cur_comm == SPI_FULL_DUPLEX || + spi->cur_comm == SPI_SIMPLEX_RX || + spi->cur_comm == SPI_3WIRE_RX)) { /* TXE flag is set and is handled when RXNE flag occurs */ sr &= ~STM32F4_SPI_SR_TXE; mask |= STM32F4_SPI_SR_RXNE | STM32F4_SPI_SR_OVR; @@ -850,8 +860,10 @@ static irqreturn_t stm32f4_spi_irq_event(int irq, void *dev_id) stm32f4_spi_read_rx(spi); if (spi->rx_len == 0) end = true; - else /* Load data for discontinuous mode */ + else if (spi->tx_buf)/* Load data for discontinuous mode */ stm32f4_spi_write_tx(spi); + else if (spi->cur_comm == SPI_SIMPLEX_RX) + stm32f4_spi_tx_dummy(spi); } end_irq: @@ -1151,7 +1163,9 @@ static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi) /* Enable the interrupts relative to the current communication mode */ if (spi->cur_comm == SPI_SIMPLEX_TX || spi->cur_comm == SPI_3WIRE_TX) { cr2 |= STM32F4_SPI_CR2_TXEIE; - } else if (spi->cur_comm == SPI_FULL_DUPLEX) { + } else if (spi->cur_comm == SPI_FULL_DUPLEX || + spi->cur_comm == SPI_SIMPLEX_RX || + spi->cur_comm == SPI_3WIRE_RX) { /* In transmit-only mode, the OVR flag is set in the SR register * since the received data are never read. Therefore set OVR * interrupt only when rx buffer is available. @@ -1170,6 +1184,8 @@ static int stm32f4_spi_transfer_one_irq(struct stm32_spi *spi) /* starting data transfer when buffer is loaded */ if (spi->tx_buf) stm32f4_spi_write_tx(spi); + else if (spi->cur_comm == SPI_SIMPLEX_RX) + stm32f4_spi_tx_dummy(spi); spin_unlock_irqrestore(&spi->lock, flags); @@ -1462,10 +1478,16 @@ static int stm32f4_spi_set_mode(struct stm32_spi *spi, unsigned int comm_type) stm32_spi_set_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_BIDIMODE | STM32F4_SPI_CR1_BIDIOE); - } else if (comm_type == SPI_FULL_DUPLEX) { + } else if (comm_type == SPI_FULL_DUPLEX || + comm_type == SPI_SIMPLEX_RX) { stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, STM32F4_SPI_CR1_BIDIMODE | STM32F4_SPI_CR1_BIDIOE); + } else if (comm_type == SPI_3WIRE_RX) { + stm32_spi_set_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIMODE); + stm32_spi_clr_bits(spi, STM32F4_SPI_CR1, + STM32F4_SPI_CR1_BIDIOE); } else { return -EINVAL; } -- 2.7.4