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From: Sowjanya Komatineni <skomatineni@nvidia.com>
To: thierry.reding@gmail.com, jonathanh@nvidia.com, talho@nvidia.com,
	skomatineni@nvidia.com, broonie@kernel.org, robh+dt@kernel.org,
	mark.rutland@arm.com, kyarlagadda@nvidia.com
Cc: ldewangan@nvidia.com, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
	devicetree@vger.kernel.org
Subject: [PATCH V1 07/26] spi: tegra114: flush fifos
Date: Tue, 26 Mar 2019 22:56:28 -0700	[thread overview]
Message-ID: <1553666207-11414-7-git-send-email-skomatineni@nvidia.com> (raw)
In-Reply-To: <1553666207-11414-1-git-send-email-skomatineni@nvidia.com>

Fixes: Flush TX and RX FIFOs before start of new transfer and on FIFO
overflow or underrun errors.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/spi/spi-tegra114.c | 39 ++++++++++++++++++++++++++++++---------
 1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index 0d20fc489134..477828051aba 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -500,22 +500,37 @@ static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
 	return 0;
 }
 
-static int tegra_spi_start_dma_based_transfer(
-		struct tegra_spi_data *tspi, struct spi_transfer *t)
+static int tegra_spi_flush_fifos(struct tegra_spi_data *tspi)
 {
-	u32 val;
-	unsigned int len;
-	int ret = 0;
+	unsigned long timeout = jiffies + HZ;
 	u32 status;
 
-	/* Make sure that Rx and Tx fifo are empty */
 	status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 	if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
-		dev_err(tspi->dev, "Rx/Tx fifo are not empty status 0x%08x\n",
-			(unsigned)status);
-		return -EIO;
+		status |= SPI_RX_FIFO_FLUSH | SPI_TX_FIFO_FLUSH;
+		tegra_spi_writel(tspi, status, SPI_FIFO_STATUS);
+		while ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
+			status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
+			if (time_after(jiffies, timeout)) {
+				dev_err(tspi->dev,
+					"timeout waiting for fifo flush\n");
+				return -EIO;
+			}
+
+			udelay(1);
+		}
 	}
 
+	return 0;
+}
+
+static int tegra_spi_start_dma_based_transfer(
+		struct tegra_spi_data *tspi, struct spi_transfer *t)
+{
+	u32 val;
+	unsigned int len;
+	int ret = 0;
+
 	val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
 	tegra_spi_writel(tspi, val, SPI_DMA_BLK);
 
@@ -781,6 +796,9 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi,
 	dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n",
 		tspi->def_command1_reg, (unsigned)command1);
 
+	ret = tegra_spi_flush_fifos(tspi);
+	if (ret < 0)
+		return ret;
 	if (total_fifo_words > SPI_FIFO_DEPTH)
 		ret = tegra_spi_start_dma_based_transfer(tspi, t);
 	else
@@ -878,6 +896,7 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
 			    (tspi->cur_direction & DATA_DIR_RX))
 				dmaengine_terminate_all(tspi->rx_dma_chan);
 			ret = -EIO;
+			tegra_spi_flush_fifos(tspi);
 			reset_control_assert(tspi->rst);
 			udelay(2);
 			reset_control_deassert(tspi->rst);
@@ -931,6 +950,7 @@ static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
 			tspi->status_reg);
 		dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
 			tspi->command1_reg, tspi->dma_control_reg);
+		tegra_spi_flush_fifos(tspi);
 		reset_control_assert(tspi->rst);
 		udelay(2);
 		reset_control_deassert(tspi->rst);
@@ -1003,6 +1023,7 @@ static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
 			tspi->status_reg);
 		dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
 			tspi->command1_reg, tspi->dma_control_reg);
+		tegra_spi_flush_fifos(tspi);
 		reset_control_assert(tspi->rst);
 		udelay(2);
 		reset_control_deassert(tspi->rst);
-- 
2.7.4

  parent reply	other threads:[~2019-03-27  5:56 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-27  5:56 [PATCH V1 01/26] spi: tegra114: fix PIO transfer Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 02/26] spi: tegra114: clear packed bit for unpacked mode Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: clear packed bit for unpacked mode" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 03/26] spi: tegra114: fix for unpacked mode transfers Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: fix for unpacked mode transfers" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 04/26] spi: tegra114: use packed mode for 32 bits per word Sowjanya Komatineni
2019-04-01  7:39   ` Mark Brown
2019-04-01 18:38     ` Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: use packed mode for 32 bits per word" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 05/26] spi: tegra114: use unpacked mode for below 4 byte transfers Sowjanya Komatineni
2019-04-01  8:26   ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 06/26] spi: tegra114: terminate dma and reset on transfer timeout Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: terminate dma and reset on transfer timeout" to the spi tree Mark Brown
2019-03-27  5:56 ` Sowjanya Komatineni [this message]
2019-04-01  8:54   ` Applied "spi: tegra114: flush fifos" " Mark Brown
2019-03-27  5:56 ` [PATCH V1 08/26] spi: tegra114: configure dma burst size to fifo trig level Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 09/26] spi: tegra114: dump SPI registers during timeout Sowjanya Komatineni
2019-04-01  7:39   ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 10/26] spi: tegra114: avoid reset call in atomic context Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 11/26] spi: tegra114: reset controller on probe Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: reset controller on probe" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 12/26] spi: tegra114: add SPI_LSB_FIRST support Sowjanya Komatineni
2019-04-01  8:54   ` Applied "spi: tegra114: add SPI_LSB_FIRST support" to the spi tree Mark Brown
2019-03-27  5:56 ` [PATCH V1 13/26] spi: tegra114: add dual mode support Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 14/26] spi: tegra114: add 3 wire transfer " Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 15/26] spi: tegra114: set supported bits_per_word Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 16/26] spi: tegra114: set bus number based on id Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 17/26] spi: tegra114: add support for interrupt mask Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 18/26] spi: tegra114: add support for hw based cs Sowjanya Komatineni
2019-04-01  7:48   ` Mark Brown
2019-04-01 18:40     ` Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 19/26] DT bindings: spi: add spi client device properties Sowjanya Komatineni
2019-04-01  7:37   ` Mark Brown
2019-04-01 17:59     ` Sowjanya Komatineni
2019-04-02  4:52       ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 20/26] spi: tegra114: add support for tuning HW CS timing Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 21/26] DT bindings: spi: add tx/rx clock delay SPI client properties Sowjanya Komatineni
2019-03-31  6:42   ` Rob Herring
2019-04-02 20:27     ` Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 22/26] spi: tegra114: add support for tuning clock delay Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 23/26] spi: tegra114: add support for gpio based cs Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 24/26] spi: tegra114: de-assert CS before SPI mode is reset to its default Sowjanya Komatineni
2019-04-01  7:49   ` Mark Brown
2019-04-01 18:07     ` Sowjanya Komatineni
2019-04-02  4:52       ` Mark Brown
2019-03-27  5:56 ` [PATCH V1 25/26] spi: expand mode and mode_bits support Sowjanya Komatineni
2019-03-27  5:56 ` [PATCH V1 26/26] spi: tegra114: add support for LSBYTE_FIRST Sowjanya Komatineni

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