redonkable/alistair23-linux
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can: mcp251x: allow to read two registers in one spi transfer

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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>
This commit is contained in:
Sascha Hauer 2010-09-28 09:53:35 +02:00 committed by Marc Kleine-Budde
parent 711e4d6ecc
commit f3a3ed3115
1 changed files with 17 additions and 3 deletions
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20
drivers/net/can/mcp251x.c
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@ -319,6 +319,20 @@ static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
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 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
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 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
mcp251x_write_bits(spi, CANINTF, intf, 0x00);
eflag = mcp251x_read_reg(spi, EFLG);
mcp251x_write_reg(spi, EFLG, 0x00);
/* Update can state */