From: Marc Kleine-Budde mkl@pengutronix.de
[ Upstream commit 617085fca6375e2c1667d1fbfc6adc4034c85f04 ]
Some SPI host controllers do not support full-duplex SPI transfers.
The function mcp251x_spi_trans() does a full duplex transfer. It is used in several places in the driver, where a TX half duplex transfer is sufficient.
To fix support for half duplex SPI host controllers, this patch introduces a new function mcp251x_spi_write() and changes all callers that do a TX half duplex transfer to use mcp251x_spi_write().
Fixes: e0e25001d088 ("can: mcp251x: add support for half duplex controllers") Link: https://lore.kernel.org/r/20210330100246.1074375-1-mkl@pengutronix.de Cc: Tim Harvey tharvey@gateworks.com Tested-By: Tim Harvey tharvey@gateworks.com Reported-by: Gerhard Bertelsmann info@gerhard-bertelsmann.de Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/can/spi/mcp251x.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 22d814ae4edc..42c3046fa304 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -314,6 +314,18 @@ static int mcp251x_spi_trans(struct spi_device *spi, int len) return ret; }
+static int mcp251x_spi_write(struct spi_device *spi, int len) +{ + struct mcp251x_priv *priv = spi_get_drvdata(spi); + int ret; + + ret = spi_write(spi, priv->spi_tx_buf, len); + if (ret) + dev_err(&spi->dev, "spi write failed: ret = %d\n", ret); + + return ret; +} + static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg) { struct mcp251x_priv *priv = spi_get_drvdata(spi); @@ -361,7 +373,7 @@ static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val) priv->spi_tx_buf[1] = reg; priv->spi_tx_buf[2] = val;
- mcp251x_spi_trans(spi, 3); + mcp251x_spi_write(spi, 3); }
static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2) @@ -373,7 +385,7 @@ static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2) priv->spi_tx_buf[2] = v1; priv->spi_tx_buf[3] = v2;
- mcp251x_spi_trans(spi, 4); + mcp251x_spi_write(spi, 4); }
static void mcp251x_write_bits(struct spi_device *spi, u8 reg, @@ -386,7 +398,7 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg, priv->spi_tx_buf[2] = mask; priv->spi_tx_buf[3] = val;
- mcp251x_spi_trans(spi, 4); + mcp251x_spi_write(spi, 4); }
static u8 mcp251x_read_stat(struct spi_device *spi) @@ -618,7 +630,7 @@ static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, buf[i]); } else { memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len); - mcp251x_spi_trans(spi, TXBDAT_OFF + len); + mcp251x_spi_write(spi, TXBDAT_OFF + len); } }
@@ -650,7 +662,7 @@ static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
/* use INSTRUCTION_RTS, to avoid "repeated frame problem" */ priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx); - mcp251x_spi_trans(priv->spi, 1); + mcp251x_spi_write(priv->spi, 1); }
static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf, @@ -888,7 +900,7 @@ static int mcp251x_hw_reset(struct spi_device *spi) mdelay(MCP251X_OST_DELAY_MS);
priv->spi_tx_buf[0] = INSTRUCTION_RESET; - ret = mcp251x_spi_trans(spi, 1); + ret = mcp251x_spi_write(spi, 1); if (ret) return ret;