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| author | Holger Waechtler <devnull@localhost> | 2003-06-16 22:56:42 +0000 |
|---|---|---|
| committer | Holger Waechtler <devnull@localhost> | 2003-06-16 22:56:42 +0000 |
| commit | e0622e268e489557031a733b25000b81cfc737fa (patch) | |
| tree | da494d52ecb55e938d133a7d90fcd44422f4c1e8 | |
| parent | e9fa3995438bfb9e0383faa4b8e9a481863db3de (diff) | |
| download | mediapointer-dvb-s2-e0622e268e489557031a733b25000b81cfc737fa.tar.gz mediapointer-dvb-s2-e0622e268e489557031a733b25000b81cfc737fa.tar.bz2 | |
try to make a more specific detection mechanism
| -rw-r--r-- | linux/drivers/media/dvb/frontends/grundig_29504-401.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/linux/drivers/media/dvb/frontends/grundig_29504-401.c b/linux/drivers/media/dvb/frontends/grundig_29504-401.c index ecf9383e7..d4cbcf8ff 100644 --- a/linux/drivers/media/dvb/frontends/grundig_29504-401.c +++ b/linux/drivers/media/dvb/frontends/grundig_29504-401.c @@ -443,30 +443,50 @@ int l64781_attach (struct dvb_i2c_bus *i2c) return -ENODEV; } + /* The chip always responds to reads */ + if (i2c->xfer(i2c, msg, 2) != 2) { + dprintk("no response to read on I2C bus\n"); + return -ENODEV; + } + + /* Save current register contents for bailout */ reg0x3e = l64781_readreg(i2c, 0x3e); - /** - * if we see a powered down L64781 we wake it up... - */ - if (reg0x3e == 0x5a) { - dprintk("waking up sleeping L64781...\n"); - l64781_writereg (i2c, 0x3e, 0xa5); + /* Reading the POWER_DOWN register always returns 0 */ + if (reg0x3e != 0) { + dprintk("Device doesn't look like L64781\n"); + return -ENODEV; } - if (i2c->xfer(i2c, msg, 2) != 2) /* nothing... */ - return -ENODEV; + /* Turn the chip off */ + l64781_writereg (i2c, 0x3e, 0x5a); - if (b1[0] != 0xa1) { /* oops, we're tried to talk to an EEPROM...*/ - l64781_writereg (i2c, 0x3e, reg0x3e); /* restore reg 0x3e */ - return -ENODEV; + /* Responds to all reads with 0 */ + if (l64781_readreg(i2c, 0x1a) != 0) { + dprintk("Read 1 returned unexpcted value\n"); + goto bailout; + } + + /* Turn the chip on */ + l64781_writereg (i2c, 0x3e, 0xa5); + + /* Responds with register default value */ + if (l64781_readreg(i2c, 0x1a) != 0xa1) { + dprintk("Read 2 returned unexpcted value\n"); + goto bailout; } dvb_register_frontend (grundig_29504_401_ioctl, i2c, NULL, &grundig_29504_401_info); return 0; + + bailout: + l64781_writereg (i2c, 0x3e, reg0x3e); /* restore reg 0x3e */ + return -ENODEV; } + static void l64781_detach (struct dvb_i2c_bus *i2c) { |