can: mcp251x: allow to read two registers in one spi transfer
This patch bases on work done earlier by David Jander.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: David Jander <david@protonic.nl>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
index fdea752..9b3466a 100644
--- a/drivers/net/can/mcp251x.c
+++ b/drivers/net/can/mcp251x.c
@@ -319,6 +319,20 @@
return val;
}
+static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
+ uint8_t *v1, uint8_t *v2)
+{
+ struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev);
+
+ priv->spi_tx_buf[0] = INSTRUCTION_READ;
+ priv->spi_tx_buf[1] = reg;
+
+ mcp251x_spi_trans(spi, 4);
+
+ *v1 = priv->spi_rx_buf[2];
+ *v2 = priv->spi_rx_buf[3];
+}
+
static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
{
struct mcp251x_priv *priv = dev_get_drvdata(&spi->dev);
@@ -754,10 +768,11 @@
mutex_lock(&priv->mcp_lock);
while (!priv->force_quit) {
enum can_state new_state;
- u8 intf = mcp251x_read_reg(spi, CANINTF);
- u8 eflag;
+ u8 intf, eflag;
int can_id = 0, data1 = 0;
+ mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
+
if (intf & CANINTF_RX0IF) {
mcp251x_hw_rx(spi, 0);
/* Free one buffer ASAP */
@@ -770,7 +785,6 @@
mcp251x_write_bits(spi, CANINTF, intf, 0x00);
- eflag = mcp251x_read_reg(spi, EFLG);
mcp251x_write_reg(spi, EFLG, 0x00);
/* Update can state */