Add locking to the various iicbus(4) bridge drivers:

- Just grab Giant in the ixp425_iic(4) driver since this driver uses
  a shared address/data register window pair to access the actual
  I2C registers.  None of the other ixp425 drivers lock access to these
  shared address/data registers yet and that would need to be done before
  this could use any meaningful locking.
- Add locking to the interrupt handler and 'iicbus_reset' methods of the
  at91_twi(4) driver.
- Add locking to the pcf(4) driver.  Other pcf(4) fixes include:
  - Don't needlessly zero the softc.
  - Use bus_foo rather than bus_space_foo and remove bus space tag and
    handle from softc.
- The lpbb(4) driver just grabs Giant for now.  This will be refined later
  when ppbus(4) is locked.
- As was done with smbus earlier, move the DRIVER_MODULE() lines to match
  the bus driver (either iicbus or iicbb) to the bridge driver into the
  bridge drivers.

Tested by:	sam (arm/ixp425)

1 files changed, 9 insertions, 0 deletions

diff --git a/sys/arm/xscale/ixp425/ixp425_iic.c b/sys/arm/xscale/ixp425/ixp425_iic.c
index ecc889f..38a86a6 100644
--- a/sys/arm/xscale/ixp425/ixp425_iic.c
+++ b/sys/arm/xscale/ixp425/ixp425_iic.c
@@ -106,9 +106,11 @@ ixpiic_getscl(device_t dev)
 	struct ixpiic_softc *sc = ixpiic_sc;
 	uint32_t reg;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
 
 	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
+	mtx_unlock(&Giant);
 	return (reg & GPIO_I2C_SCL_BIT);
 }
 
@@ -118,9 +120,11 @@ ixpiic_getsda(device_t dev)
 	struct ixpiic_softc *sc = ixpiic_sc;
 	uint32_t reg;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
 
 	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
+	mtx_unlock(&Giant);
 	return (reg & GPIO_I2C_SDA_BIT);
 }
 
@@ -129,11 +133,13 @@ ixpiic_setsda(device_t dev, char val)
 {
 	struct ixpiic_softc *sc = ixpiic_sc;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SDA_BIT);
 	if (val)
 		GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
 	else
 		GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
+	mtx_unlock(&Giant);
 	DELAY(I2C_DELAY);
 }
 
@@ -142,11 +148,13 @@ ixpiic_setscl(device_t dev, char val)
 {
 	struct ixpiic_softc *sc = ixpiic_sc;
 
+	mtx_lock(&Giant);
 	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SCL_BIT);
 	if (val)
 		GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
 	else
 		GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
+	mtx_unlock(&Giant);
 	DELAY(I2C_DELAY);
 }
 
@@ -184,3 +192,4 @@ static driver_t ixpiic_driver = {
 static devclass_t ixpiic_devclass;
 
 DRIVER_MODULE(ixpiic, ixp, ixpiic_driver, ixpiic_devclass, 0, 0);
+DRIVER_MODULE(iicbb, ixpiic, iicbb_driver, iicbb_devclass, 0, 0);