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, 14 insertions, 6 deletions

diff --git a/sys/dev/pcf/pcfvar.h b/sys/dev/pcf/pcfvar.h
index ed4d9d8..8e4d5d8 100644
--- a/sys/dev/pcf/pcfvar.h
+++ b/sys/dev/pcf/pcfvar.h
@@ -27,6 +27,9 @@
  * $FreeBSD$
  */
 
+#ifndef __PCFVAR_H__
+#define	__PCFVAR_H__
+
 #define IO_PCFSIZE	2
 
 #define TIMEOUT	9999					/* XXX */
@@ -63,19 +66,22 @@ struct pcf_softc {
 	int	pcf_slave_mode;		/* receiver or transmitter */
 	int	pcf_started;		/* 1 if start condition sent */
 
+	struct mtx pcf_lock;
 	device_t iicbus;		/* the corresponding iicbus */
 
 	/* Resource handling stuff. */
 	struct resource		*res_ioport;
 	int			rid_ioport;
-	bus_space_tag_t		bt_ioport;
-	bus_space_handle_t	bh_ioport;
 	struct resource		*res_irq;
 	int			rid_irq;
 	void			*intr_cookie;
 };
 #define DEVTOSOFTC(dev) ((struct pcf_softc *)device_get_softc(dev))
 
+#define	PCF_LOCK(sc)		mtx_lock(&(sc)->pcf_lock)
+#define	PCF_UNLOCK(sc)		mtx_unlock(&(sc)->pcf_lock)
+#define	PCF_ASSERT_LOCKED(sc)	mtx_assert(&(sc)->pcf_lock, MA_OWNED)
+
 /*
  * PCF8584 datasheet : when operate at 8 MHz or more, a minimun time of
  * 6 clocks cycles must be left between two consecutives access
@@ -92,7 +98,7 @@ static __inline void
 pcf_set_S0(struct pcf_softc *sc, int data)
 {
 
-	bus_space_write_1(sc->bt_ioport, sc->bh_ioport, 0, data);
+	bus_write_1(sc->res_ioport, 0, data);
 	pcf_nops();
 }
 
@@ -100,7 +106,7 @@ static __inline void
 pcf_set_S1(struct pcf_softc *sc, int data)
 {
 
-	bus_space_write_1(sc->bt_ioport, sc->bh_ioport, 1, data);
+	bus_write_1(sc->res_ioport, 1, data);
 	pcf_nops();
 }
 
@@ -109,7 +115,7 @@ pcf_get_S0(struct pcf_softc *sc)
 {
 	char data;
 
-	data = bus_space_read_1(sc->bt_ioport, sc->bh_ioport, 0);
+	data = bus_read_1(sc->res_ioport, 0);
 	pcf_nops();
 
 	return (data);
@@ -120,7 +126,7 @@ pcf_get_S1(struct pcf_softc *sc)
 {
 	char data;
 
-	data = bus_space_read_1(sc->bt_ioport, sc->bh_ioport, 1);
+	data = bus_read_1(sc->res_ioport, 1);
 	pcf_nops();
 
 	return (data);
@@ -138,3 +144,5 @@ extern driver_intr_t pcf_intr;
 #define PCF_MINVER	1
 #define PCF_MAXVER	1
 #define PCF_PREFVER	PCF_MODVER
+
+#endif /* !__PCFVAR_H__ */