From patchwork Fri Apr 24 10:42:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dilip Kota X-Patchwork-Id: 11507499 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8440613B2 for ; Fri, 24 Apr 2020 10:43:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 723522071E for ; Fri, 24 Apr 2020 10:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726907AbgDXKne (ORCPT ); Fri, 24 Apr 2020 06:43:34 -0400 Received: from mga14.intel.com ([192.55.52.115]:54501 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726815AbgDXKnd (ORCPT ); Fri, 24 Apr 2020 06:43:33 -0400 IronPort-SDR: tRR8oNGNPruI9ica38lPNORZtfJi+vwlzNeCzoqtiPu/DrviI2yH4PkkIeezhpi5QL/SNWNmkn zSsN4zunMOJw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Apr 2020 03:43:32 -0700 IronPort-SDR: qH+g6aud2kSY1yU53VAt1ke6qVjY8cWTVhupc5SVjH37+rB75skLOFbepHF+kIN/f9nH8yGVZB jN2me8jxPCcQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,311,1583222400"; d="scan'208";a="274560638" Received: from sgsxdev004.isng.intel.com (HELO localhost) ([10.226.88.13]) by orsmga002.jf.intel.com with ESMTP; 24 Apr 2020 03:43:29 -0700 From: Dilip Kota To: broonie@kernel.org, robh@kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org Cc: linux-kernel@vger.kernel.org, daniel.schwierzeck@gmail.com, hauke@hauke-m.de, andriy.shevchenko@intel.com, cheol.yong.kim@intel.com, chuanhua.lei@linux.intel.com, qi-ming.wu@intel.com, Dilip Kota Subject: [PATCH 1/4] spi: lantiq: Synchronize interrupt handlers and transfers Date: Fri, 24 Apr 2020 18:42:30 +0800 Message-Id: <3bf88d24b9cad9f3df1da8ed65bf55c05693b0f2.1587702428.git.eswara.kota@linux.intel.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Synchronize tx, rx and error interrupts by registering to the same interrupt handler. Interrupt handler will recognize and process the appropriate interrupt on the basis of interrupt status register. Also, establish synchronization between the interrupt handler and transfer operation by taking the locks and registering the interrupt handler as thread IRQ which avoids the bottom half. Fixes the wrongly populated interrupt register offsets too. Fixes: 17f84b793c01 ("spi: lantiq-ssc: add support for Lantiq SSC SPI controller") Fixes: ad2fca0721d1 ("spi: lantiq-ssc: add LTQ_ prefix to defines") Signed-off-by: Dilip Kota --- drivers/spi/spi-lantiq-ssc.c | 89 ++++++++++++++++++++++---------------------- 1 file changed, 45 insertions(+), 44 deletions(-) diff --git a/drivers/spi/spi-lantiq-ssc.c b/drivers/spi/spi-lantiq-ssc.c index 1fd7ee53d451..b67f5925bcb0 100644 --- a/drivers/spi/spi-lantiq-ssc.c +++ b/drivers/spi/spi-lantiq-ssc.c @@ -6,6 +6,7 @@ #include #include +#include #include #include #include @@ -13,7 +14,6 @@ #include #include #include -#include #include #include #include @@ -50,8 +50,8 @@ #define LTQ_SPI_RXCNT 0x84 #define LTQ_SPI_DMACON 0xec #define LTQ_SPI_IRNEN 0xf4 -#define LTQ_SPI_IRNICR 0xf8 -#define LTQ_SPI_IRNCR 0xfc +#define LTQ_SPI_IRNCR 0xf8 +#define LTQ_SPI_IRNICR 0xfc #define LTQ_SPI_CLC_SMC_S 16 /* Clock divider for sleep mode */ #define LTQ_SPI_CLC_SMC_M (0xFF << LTQ_SPI_CLC_SMC_S) @@ -171,9 +171,7 @@ struct lantiq_ssc_spi { struct clk *fpi_clk; const struct lantiq_ssc_hwcfg *hwcfg; - spinlock_t lock; - struct workqueue_struct *wq; - struct work_struct work; + struct mutex lock; const u8 *tx; u8 *rx; @@ -186,6 +184,8 @@ struct lantiq_ssc_spi { unsigned int base_cs; }; +static void lantiq_ssc_busy_wait(struct lantiq_ssc_spi *spi); + static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg) { return __raw_readl(spi->regbase + reg); @@ -464,8 +464,6 @@ static int lantiq_ssc_unprepare_message(struct spi_master *master, { struct lantiq_ssc_spi *spi = spi_master_get_devdata(master); - flush_workqueue(spi->wq); - /* Disable transmitter and receiver while idle */ lantiq_ssc_maskl(spi, 0, LTQ_SPI_CON_TXOFF | LTQ_SPI_CON_RXOFF, LTQ_SPI_CON); @@ -610,10 +608,8 @@ static void rx_request(struct lantiq_ssc_spi *spi) lantiq_ssc_writel(spi, rxreq, LTQ_SPI_RXREQ); } -static irqreturn_t lantiq_ssc_xmit_interrupt(int irq, void *data) +static irqreturn_t lantiq_ssc_xmit_interrupt(struct lantiq_ssc_spi *spi) { - struct lantiq_ssc_spi *spi = data; - if (spi->tx) { if (spi->rx && spi->rx_todo) rx_fifo_read_full_duplex(spi); @@ -638,19 +634,15 @@ static irqreturn_t lantiq_ssc_xmit_interrupt(int irq, void *data) return IRQ_HANDLED; completed: - queue_work(spi->wq, &spi->work); + lantiq_ssc_busy_wait(spi); return IRQ_HANDLED; } -static irqreturn_t lantiq_ssc_err_interrupt(int irq, void *data) +static irqreturn_t lantiq_ssc_err_interrupt(struct lantiq_ssc_spi *spi) { - struct lantiq_ssc_spi *spi = data; u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT); - if (!(stat & LTQ_SPI_STAT_ERRORS)) - return IRQ_NONE; - if (stat & LTQ_SPI_STAT_RUE) dev_err(spi->dev, "receive underflow error\n"); if (stat & LTQ_SPI_STAT_TUE) @@ -670,17 +662,39 @@ static irqreturn_t lantiq_ssc_err_interrupt(int irq, void *data) /* set bad status so it can be retried */ if (spi->master->cur_msg) spi->master->cur_msg->status = -EIO; - queue_work(spi->wq, &spi->work); + + spi_finalize_current_transfer(spi->master); return IRQ_HANDLED; } +static irqreturn_t lantiq_ssc_isr(int irq, void *data) +{ + struct lantiq_ssc_spi *spi = data; + const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; + irqreturn_t ret = IRQ_NONE; + u32 val; + + mutex_lock(&spi->lock); + val = lantiq_ssc_readl(spi, LTQ_SPI_IRNCR); + lantiq_ssc_maskl(spi, val, 0, LTQ_SPI_IRNEN); + + if (val & LTQ_SPI_IRNEN_E) + ret = lantiq_ssc_err_interrupt(spi); + + if ((val & hwcfg->irnen_t) || (val & hwcfg->irnen_r)) + ret = lantiq_ssc_xmit_interrupt(spi); + + lantiq_ssc_maskl(spi, 0, val, LTQ_SPI_IRNEN); + mutex_unlock(&spi->lock); + + return ret; +} + static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev, struct spi_transfer *t) { - unsigned long flags; - - spin_lock_irqsave(&spi->lock, flags); + mutex_lock(&spi->lock); spi->tx = t->tx_buf; spi->rx = t->rx_buf; @@ -700,7 +714,7 @@ static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev, rx_request(spi); } - spin_unlock_irqrestore(&spi->lock, flags); + mutex_unlock(&spi->lock); return t->len; } @@ -712,14 +726,11 @@ static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev, * write the last word to the wire, not when it is finished. Do busy * waiting till it finishes. */ -static void lantiq_ssc_bussy_work(struct work_struct *work) +static void lantiq_ssc_busy_wait(struct lantiq_ssc_spi *spi) { - struct lantiq_ssc_spi *spi; unsigned long long timeout = 8LL * 1000LL; unsigned long end; - spi = container_of(work, typeof(*spi), work); - do_div(timeout, spi->speed_hz); timeout += timeout + 100; /* some tolerance */ @@ -838,18 +849,18 @@ static int lantiq_ssc_probe(struct platform_device *pdev) goto err_master_put; } - err = devm_request_irq(dev, rx_irq, lantiq_ssc_xmit_interrupt, - 0, LTQ_SPI_RX_IRQ_NAME, spi); + err = devm_request_threaded_irq(dev, rx_irq, NULL, lantiq_ssc_isr, + IRQF_ONESHOT, LTQ_SPI_RX_IRQ_NAME, spi); if (err) goto err_master_put; - err = devm_request_irq(dev, tx_irq, lantiq_ssc_xmit_interrupt, - 0, LTQ_SPI_TX_IRQ_NAME, spi); + err = devm_request_threaded_irq(dev, tx_irq, NULL, lantiq_ssc_isr, + IRQF_ONESHOT, LTQ_SPI_TX_IRQ_NAME, spi); if (err) goto err_master_put; - err = devm_request_irq(dev, err_irq, lantiq_ssc_err_interrupt, - 0, LTQ_SPI_ERR_IRQ_NAME, spi); + err = devm_request_threaded_irq(dev, err_irq, NULL, lantiq_ssc_isr, + IRQF_ONESHOT, LTQ_SPI_ERR_IRQ_NAME, spi); if (err) goto err_master_put; @@ -882,7 +893,7 @@ static int lantiq_ssc_probe(struct platform_device *pdev) spi->base_cs = 1; of_property_read_u32(pdev->dev.of_node, "base-cs", &spi->base_cs); - spin_lock_init(&spi->lock); + mutex_init(&spi->lock); spi->bits_per_word = 8; spi->speed_hz = 0; @@ -899,13 +910,6 @@ static int lantiq_ssc_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 8) | SPI_BPW_MASK(16) | SPI_BPW_MASK(32); - spi->wq = alloc_ordered_workqueue(dev_name(dev), 0); - if (!spi->wq) { - err = -ENOMEM; - goto err_clk_put; - } - INIT_WORK(&spi->work, lantiq_ssc_bussy_work); - id = lantiq_ssc_readl(spi, LTQ_SPI_ID); spi->tx_fifo_size = (id & LTQ_SPI_ID_TXFS_M) >> LTQ_SPI_ID_TXFS_S; spi->rx_fifo_size = (id & LTQ_SPI_ID_RXFS_M) >> LTQ_SPI_ID_RXFS_S; @@ -921,13 +925,11 @@ static int lantiq_ssc_probe(struct platform_device *pdev) err = devm_spi_register_master(dev, master); if (err) { dev_err(dev, "failed to register spi_master\n"); - goto err_wq_destroy; + goto err_clk_put; } return 0; -err_wq_destroy: - destroy_workqueue(spi->wq); err_clk_put: clk_put(spi->fpi_clk); err_clk_disable: @@ -948,7 +950,6 @@ static int lantiq_ssc_remove(struct platform_device *pdev) tx_fifo_flush(spi); hw_enter_config_mode(spi); - destroy_workqueue(spi->wq); clk_disable_unprepare(spi->spi_clk); clk_put(spi->fpi_clk);