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authorMarc Kleine-Budde <mkl@pengutronix.de>2021-03-30 12:46:07 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2021-04-06 13:31:21 +0300
commit617085fca6375e2c1667d1fbfc6adc4034c85f04 (patch)
treeded19c17fed5c597d28d842d4c8e0bd7385263d9 /drivers
parent08c27f3322fec11950b8f1384aa0f3b11d028528 (diff)
downloadlinux-617085fca6375e2c1667d1fbfc6adc4034c85f04.tar.xz
can: mcp251x: fix support for half duplex SPI host controllers
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/can/spi/mcp251x.c24
1 files changed, 18 insertions, 6 deletions
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index f69fb4238a65..a57da43680d8 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;