On Tuesday 28 October 2008, Kaiwan N Billimoria wrote:
> Hi,
>
> Got a chance to test this patch today..
> short answer: no it did not seem to work.
Well, then can you see what the issue is then?
The current mainline code is clearly buggy...
> I got readings with largish negative values (from /sys/.../temp1_input);
> have not really had the time to debug this..
>
> [Sorry have not pasted o/p here becoz i do the work on an office PC,
> where i built the 2.6.28-rc2 kernel & tried this; a bit misconfigured so
> graphics did not come up (hence no clipboard stuff)...
> Also, am writing this email off my notebook where i can't test the
> device as it has no parport.]
>
> Of course, in the first place, that's why the logic is the way it is.
I think there must be bugs covering up for each other...
> I can (re)confirm though that for the LM70 chip the temperature register
> is sent MSB first...
Right, which is why the lm70.c code should use the
> -?????raw = (rxbuf[1] << 8) + rxbuf[0];
> +?????raw = (rxbuf[0] << 8) + rxbuf[1];
So the question is then what *else* is going on (buggy)
that the previous code seemed to work despite that bug...
- Dave
> Let me know,
>
> -kaiwan.
>
> On Fri, 2008-10-24 at 02:21 -0700, David Brownell wrote:
>
> > I suspect the following should do the job ... it has
> > the parport based adapter leave the data in MSB-first
> > byte order, with the lm70 driver converting to CPU
> > byte order. (In a way that will match the TMP121/123
> > support.)
> >
> > - Dave
> >
> > ---
> > drivers/hwmon/lm70.c | 4 +++-
> > drivers/spi/spi_lm70llp.c | 19 +++----------------
> > 2 files changed, 6 insertions(+), 17 deletions(-)
> >
> > --- a/drivers/hwmon/lm70.c
> > +++ b/drivers/hwmon/lm70.c
> > @@ -67,7 +67,7 @@ static ssize_t lm70_sense_temp(struct de
> > }
> > dev_dbg(dev, "rxbuf[1] : 0x%x rxbuf[0] : 0x%x\n", rxbuf[1], rxbuf[0]);
> >
> > - raw = (rxbuf[1] << 8) + rxbuf[0];
> > + raw = (rxbuf[0] << 8) + rxbuf[1];
> > dev_dbg(dev, "raw=0x%x\n", raw);
> >
> > /*
> > @@ -109,6 +109,8 @@ static int __devinit lm70_probe(struct s
> > if ((spi->mode & (SPI_CPOL|SPI_CPHA)) || !(spi->mode & SPI_3WIRE))
> > return -EINVAL;
> >
> > + /* NOTE: we assume 8-bit words, and convert to 16 bits manually */
> > +
> > p_lm70 = kzalloc(sizeof *p_lm70, GFP_KERNEL);
> > if (!p_lm70)
> > return -ENOMEM;
> > --- a/drivers/spi/spi_lm70llp.c
> > +++ b/drivers/spi/spi_lm70llp.c
> > @@ -173,6 +173,8 @@ static void lm70_chipselect(struct spi_d
> > {
> > struct spi_lm70llp *pp = spidev_to_pp(spi);
> >
> > + /* REVISIT initialize the clock polarity ... */
> > +
> > if (value)
> > assertCS(pp);
> > else
> > @@ -184,22 +186,7 @@ static void lm70_chipselect(struct spi_d
> > */
> > static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits)
> > {
> > - static u32 sio=0;
> > - static int first_time=1;
> > -
> > - /* First time: perform SPI bitbang and return the LSB of
> > - * the result of the SPI call.
> > - */
> > - if (first_time) {
> > - sio = bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
> > - first_time=0;
> > - return (sio & 0x00ff);
> > - }
> > - /* Return the MSB of the result of the SPI call */
> > - else {
> > - first_time=1;
> > - return (sio >> 8);
> > - }
> > + return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits);
> > }
> >
> > static void spi_lm70llp_attach(struct parport *p)
>
>
>
