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Add an iicbus_reset() method to bcm2835_bsc. While it is generally not

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used for kernel devices it is used by i2c(8).

This fix the 'error: Device not configured' when i2c(8) tries to reset the
controller, as an example:

# i2c -r
Resetting I2C controller on /dev/iic0: error: Device not configured

For now use conservative settings for default i2c speeds.

MFC after:	1 week
This commit is contained in:
Luiz Otavio O Souza 2014-10-24 22:06:21 +00:00
parent f53389946d
commit e50c624155
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=273610
2 changed files with 40 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
sys/arm/broadcom/bcm2835/bcm2835_bsc.c
View File

@ -210,6 +210,8 @@ static void
bcm_bsc_reset(struct bcm_bsc_softc *sc)
{
/* Enable the BSC Controller, disable interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN);
/* Clear pending interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_STATUS, BCM_BSC_STATUS_CLKT |
BCM_BSC_STATUS_ERR | BCM_BSC_STATUS_DONE);
@ -302,7 +304,6 @@ bcm_bsc_attach(device_t dev)
/* Enable the BSC controller. Flush the FIFO. */
BCM_BSC_LOCK(sc);
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN);
bcm_bsc_reset(sc);
BCM_BSC_UNLOCK(sc);
@ -351,9 +352,8 @@ bcm_bsc_intr(void *arg)
/* Check for errors. */
if (status & (BCM_BSC_STATUS_CLKT | BCM_BSC_STATUS_ERR)) {
/* Disable interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN);
sc->sc_flags |= BCM_I2C_ERROR;
bcm_bsc_reset(sc);
sc->sc_flags |= BCM_I2C_ERROR;
wakeup(sc->sc_dev);
BCM_BSC_UNLOCK(sc);
return;
@ -375,7 +375,6 @@ bcm_bsc_intr(void *arg)
if (status & BCM_BSC_STATUS_DONE) {
/* Disable interrupts. */
BCM_BSC_WRITE(sc, BCM_BSC_CTRL, BCM_BSC_CTRL_I2CEN);
bcm_bsc_reset(sc);
wakeup(sc->sc_dev);
}
@ -459,6 +458,38 @@ bcm_bsc_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
return (err);
}
static int
bcm_bsc_iicbus_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
struct bcm_bsc_softc *sc;
uint32_t freq;
sc = device_get_softc(dev);
BCM_BSC_LOCK(sc);
bcm_bsc_reset(sc);
freq = 0;
switch (speed) {
case IIC_SLOW:
freq = BCM_BSC_SLOW;
break;
case IIC_FAST:
freq = BCM_BSC_FAST;
break;
case IIC_FASTEST:
freq = BCM_BSC_FASTEST;
break;
case IIC_UNKNOWN:
default:
/* Reuse last frequency. */
break;
}
if (freq != 0)
BCM_BSC_WRITE(sc, BCM_BSC_CLOCK, BCM_BSC_CORE_CLK / freq);
BCM_BSC_UNLOCK(sc);
return (IIC_ENOADDR);
}
static phandle_t
bcm_bsc_get_node(device_t bus, device_t dev)
{
@ -474,6 +505,7 @@ static device_method_t bcm_bsc_methods[] = {
DEVMETHOD(device_detach, bcm_bsc_detach),
/* iicbus interface */
DEVMETHOD(iicbus_reset, bcm_bsc_iicbus_reset),
DEVMETHOD(iicbus_callback, iicbus_null_callback),
DEVMETHOD(iicbus_transfer, bcm_bsc_transfer),

4
sys/arm/broadcom/bcm2835/bcm2835_bscvar.h
View File

@ -56,6 +56,10 @@ struct bcm_bsc_softc {
#define BCM_I2C_READ 0x02
#define BCM_I2C_ERROR 0x04
#define BCM_BSC_SLOW 10000 /* 10 kHz. */
#define BCM_BSC_FAST 50000 /* 50 kHz. */
#define BCM_BSC_FASTEST 100000 /* 100 kHz. */
#define BCM_BSC_WRITE(_sc, _off, _val) \
bus_space_write_4(_sc->sc_bst, _sc->sc_bsh, _off, _val)
#define BCM_BSC_READ(_sc, _off) \