diff options
Diffstat (limited to 'target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch')
| -rw-r--r-- | target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch b/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch new file mode 100644 index 0000000000..aabf1b9b1e --- /dev/null +++ b/target/linux/octeontx/patches-5.4/0003-can-mcp251x-convert-to-half-duplex-SPI.patch @@ -0,0 +1,51 @@ +From 6edfb172ff1dd3cfc84c19790c245a4005474bb7 Mon Sep 17 00:00:00 2001 +From: Tim Harvey <tharvey@gateworks.com> +Date: Tue, 25 Feb 2020 12:01:36 -0800 +Subject: [PATCH 03/12] can: mcp251x: convert to half-duplex SPI + +Some SPI host controllers such as the Cavium Thunder do not support +full-duplex SPI. Using half-duplex transfers allows the driver to work +with those host controllers. + +Signed-off-by: Tim Harvey <tharvey@gateworks.com> +--- + drivers/net/can/spi/mcp251x.c | 10 +++++----- + 1 file changed, 5 insertions(+), 5 deletions(-) + +diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c +index 0b0dd3f0..c655b29 100644 +--- a/drivers/net/can/spi/mcp251x.c ++++ b/drivers/net/can/spi/mcp251x.c +@@ -345,8 +345,7 @@ static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) + priv->spi_tx_buf[0] = INSTRUCTION_READ; + priv->spi_tx_buf[1] = reg; + +- mcp251x_spi_trans(spi, 3); +- val = priv->spi_rx_buf[2]; ++ spi_write_then_read(spi, priv->spi_tx_buf, 2, &val, 1); + + return val; + } +@@ -354,15 +353,16 @@ static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) + static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg, + uint8_t *v1, uint8_t *v2) + { ++ u8 val[4] = {0}; + struct mcp251x_priv *priv = spi_get_drvdata(spi); + + priv->spi_tx_buf[0] = INSTRUCTION_READ; + priv->spi_tx_buf[1] = reg; + +- mcp251x_spi_trans(spi, 4); ++ spi_write_then_read(spi, priv->spi_tx_buf, 2, val, 2); + +- *v1 = priv->spi_rx_buf[2]; +- *v2 = priv->spi_rx_buf[3]; ++ *v1 = val[0]; ++ *v2 = val[1]; + } + + static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) +-- +2.7.4 + |