diff options
author | Adrian Chadd <adrian@FreeBSD.org> | 2011-12-20 02:49:01 +0000 |
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committer | Adrian Chadd <adrian@FreeBSD.org> | 2011-12-20 02:49:01 +0000 |
commit | fd06fec782f7b0a93e36eef087db40642e428f56 (patch) | |
tree | 8cc5375f2f11f31e02cddfae17ee99de4ed9e851 /sys | |
parent | 823efe3764450e8f446a2c22f58f3a449b400aa3 (diff) | |
download | src-fd06fec782f7b0a93e36eef087db40642e428f56.tar.gz src-fd06fec782f7b0a93e36eef087db40642e428f56.zip |
IIC bitbang changes - prepare to make the bit delay configurable; debug print changes.
* Right now the delay is hard coded at 10uS. This is a bit long when doing lots
of periodic i2c transactions. So create a 'udelay' parameter and initialise it
to 10. This can be tuned later.
* Add a newline after a transaction finishes, so the debugging output isn't so
horrible.
Notes
Notes:
svn path=/head/; revision=228728
Diffstat (limited to 'sys')
-rw-r--r-- | sys/dev/iicbus/iicbb.c | 73 |
1 files changed, 42 insertions, 31 deletions
diff --git a/sys/dev/iicbus/iicbb.c b/sys/dev/iicbus/iicbb.c index 2bc632143b5f..a7eb2a093759 100644 --- a/sys/dev/iicbus/iicbb.c +++ b/sys/dev/iicbus/iicbb.c @@ -61,6 +61,7 @@ __FBSDID("$FreeBSD$"); struct iicbb_softc { device_t iicbus; + int udelay; /* signal toggle delay in usec */ }; static int iicbb_attach(device_t); @@ -123,6 +124,7 @@ iicbb_attach(device_t dev) sc->iicbus = device_add_child(dev, "iicbus", -1); if (!sc->iicbus) return (ENXIO); + sc->udelay = 10; /* 10 uS default */ bus_generic_attach(dev); return (0); @@ -184,20 +186,18 @@ iicbb_print_child(device_t bus, device_t dev) return (retval); } -#define IIC_DELAY 10 - -#define I2C_SETSDA(dev,val) do { \ +#define I2C_SETSDA(sc,dev,val) do { \ IICBB_SETSDA(device_get_parent(dev), val); \ - DELAY(IIC_DELAY); \ + DELAY(sc->udelay); \ } while (0) #define I2C_SETSCL(dev,val) do { \ iicbb_setscl(dev, val, 100); \ } while (0) -#define I2C_SET(dev,ctrl,data) do { \ +#define I2C_SET(sc,dev,ctrl,data) do { \ I2C_SETSCL(dev, ctrl); \ - I2C_SETSDA(dev, data); \ + I2C_SETSDA(sc, dev, data); \ } while (0) #define I2C_GETSDA(dev) (IICBB_GETSDA(device_get_parent(dev))) @@ -216,34 +216,39 @@ static int i2c_debug = 0; static void iicbb_setscl(device_t dev, int val, int timeout) { + struct iicbb_softc *sc = device_get_softc(dev); int k = 0; IICBB_SETSCL(device_get_parent(dev), val); - DELAY(IIC_DELAY); + DELAY(sc->udelay); while (val && !I2C_GETSCL(dev) && k++ < timeout) { IICBB_SETSCL(device_get_parent(dev), val); - DELAY(IIC_DELAY); + DELAY(sc->udelay); } - + return; } static void iicbb_one(device_t dev, int timeout) { - I2C_SET(dev,0,1); - I2C_SET(dev,1,1); - I2C_SET(dev,0,1); + struct iicbb_softc *sc = device_get_softc(dev); + + I2C_SET(sc,dev,0,1); + I2C_SET(sc,dev,1,1); + I2C_SET(sc,dev,0,1); return; } static void iicbb_zero(device_t dev, int timeout) { - I2C_SET(dev,0,0); - I2C_SET(dev,1,0); - I2C_SET(dev,0,0); + struct iicbb_softc *sc = device_get_softc(dev); + + I2C_SET(sc,dev,0,0); + I2C_SET(sc,dev,1,0); + I2C_SET(sc,dev,0,0); return; } @@ -264,20 +269,21 @@ iicbb_zero(device_t dev, int timeout) static int iicbb_ack(device_t dev, int timeout) { + struct iicbb_softc *sc = device_get_softc(dev); int noack; int k = 0; - - I2C_SET(dev,0,1); - I2C_SET(dev,1,1); + + I2C_SET(sc,dev,0,1); + I2C_SET(sc,dev,1,1); do { noack = I2C_GETSDA(dev); if (!noack) break; - DELAY(10); - k += 10; + DELAY(1); + k++; } while (k < timeout); - I2C_SET(dev,0,1); + I2C_SET(sc,dev,0,1); I2C_DEBUG(printf("%c ",noack?'-':'+')); return (noack); @@ -302,16 +308,17 @@ iicbb_sendbyte(device_t dev, u_char data, int timeout) static u_char iicbb_readbyte(device_t dev, int last, int timeout) { + struct iicbb_softc *sc = device_get_softc(dev); int i; unsigned char data=0; - - I2C_SET(dev,0,1); + + I2C_SET(sc,dev,0,1); for (i=7; i>=0; i--) { - I2C_SET(dev,1,1); + I2C_SET(sc,dev,1,1); if (I2C_GETSDA(dev)) data |= (1<<i); - I2C_SET(dev,0,1); + I2C_SET(sc,dev,0,1); } if (last) { iicbb_one(dev, timeout); @@ -337,13 +344,14 @@ iicbb_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) static int iicbb_start(device_t dev, u_char slave, int timeout) { + struct iicbb_softc *sc = device_get_softc(dev); int error; I2C_DEBUG(printf("<")); - I2C_SET(dev,1,1); - I2C_SET(dev,1,0); - I2C_SET(dev,0,0); + I2C_SET(sc,dev,1,1); + I2C_SET(sc,dev,1,0); + I2C_SET(sc,dev,0,0); /* send address */ iicbb_sendbyte(dev, slave, timeout); @@ -364,10 +372,13 @@ error: static int iicbb_stop(device_t dev) { - I2C_SET(dev,0,0); - I2C_SET(dev,1,0); - I2C_SET(dev,1,1); + struct iicbb_softc *sc = device_get_softc(dev); + + I2C_SET(sc,dev,0,0); + I2C_SET(sc,dev,1,0); + I2C_SET(sc,dev,1,1); I2C_DEBUG(printf(">")); + I2C_DEBUG(printf("\n")); return (0); } |