Hi, On Wed, Oct 31, 2012 at 04:18:15PM +0530, Shubhrajyoti wrote: > On Wednesday 31 October 2012 03:42 PM, Felipe Balbi wrote: > > Hi, > > > > On Wed, Oct 31, 2012 at 02:29:19PM +0530, Shubhrajyoti D wrote: > >> The revision register on OMAP4 is a 16-bit lo and a 16-bit > >> hi. Currently the driver reads only the lower 8-bits. > >> Fix the same by preventing the truncating of the rev register > >> for OMAP4. > > very good, but you need to test this with OMAP2/3/4 (5 ??). How was this > > tested ? > > > >> Also use the scheme bit ie bit-14 of the hi register to know if it > >> is OMAP_I2C_IP_VERSION_2. > >> > >> On platforms previous to OMAP4 the offset 0x04 is IE register whose > >> bit-14 reset value is 0, the code uses the same to its advantage. > >> > >> The dev->regs is populated after reading the rev_hi. A NULL check > >> has been added in the resume handler to prevent the access before > >> the setting of the regs. > > this could get some rephrasing, I guess. At least to me it's difficult > > to understand what you mean :-s > > > >> Signed-off-by: Shubhrajyoti D <[email protected]> > >> --- > >> todo: some of the flag checks can be removed in favour of revision check. > >> > >> drivers/i2c/busses/i2c-omap.c | 35 +++++++++++++++++++++++++---------- > >> 1 files changed, 25 insertions(+), 10 deletions(-) > >> > >> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > >> index db31eae..651a7f7 100644 > >> --- a/drivers/i2c/busses/i2c-omap.c > >> +++ b/drivers/i2c/busses/i2c-omap.c > >> @@ -51,7 +51,8 @@ > >> /* I2C controller revisions present on specific hardware */ > >> #define OMAP_I2C_REV_ON_2430 0x36 > >> #define OMAP_I2C_REV_ON_3430_3530 0x3C > >> -#define OMAP_I2C_REV_ON_3630_4430 0x40 > >> +#define OMAP_I2C_REV_ON_3630 0x40 > >> +#define OMAP_I2C_REV_ON_4430_PLUS 0x5040 > > I would rather see a proper decoding of the revision, meaning that you > > would: > > > > For omap2/3: > > > > rev major = rev >> 8; > > rev minor = rev & 0xff; > you mean > > rev major = rev >> 4; > rev minor = rev & 0xf;
might be, I didn't look at the TRM to make sure, my bad :-)
> thats doable too. However that currently that is read together
> currently.
and that's what's wrong IMHO. What's current in driver is only valid for
OMAP1 IIRC.
> > For OMAP4/5:
> >
> > well, that's a lot more complex, but you have that data ;-)
> >
> >> /* timeout waiting for the controller to respond */
> >> #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
> >> @@ -202,7 +203,7 @@ struct omap_i2c_dev {
> >> * fifo_size==0 implies no fifo
> >> * if set, should be trsh+1
> >> */
> >> - u8 rev;
> >> + u16 rev;
> > IMHO this should be u32, so you don't need rev_lo and rev_hi below.
> >
> >> unsigned b_hw:1; /* bad h/w fixes */
> >> unsigned receiver:1; /* true when we're in receiver
> >> mode */
> >> u16 iestate; /* Saved interrupt register */
> >> @@ -490,7 +491,7 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev
> >> *dev, u8 size, bool is_rx)
> >>
> >> omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
> >>
> >> - if (dev->rev < OMAP_I2C_REV_ON_3630_4430)
> >> + if (dev->rev < OMAP_I2C_REV_ON_3630)
> >> dev->b_hw = 1; /* Enable hardware fixes */
> >>
> >> /* calculate wakeup latency constraint for MPU */
> >> @@ -1064,6 +1065,8 @@ omap_i2c_probe(struct platform_device *pdev)
> >> const struct of_device_id *match;
> >> int irq;
> >> int r;
> >> + u16 rev_lo;
> >> + u16 rev_hi;
> >>
> >> /* NOTE: driver uses the static register mapping */
> >> mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> @@ -1117,11 +1120,6 @@ omap_i2c_probe(struct platform_device *pdev)
> >>
> >> dev->reg_shift = (dev->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
> >>
> >> - if (dev->dtrev == OMAP_I2C_IP_VERSION_2)
> >> - dev->regs = (u8 *)reg_map_ip_v2;
> >> - else
> >> - dev->regs = (u8 *)reg_map_ip_v1;
> >> -
> >> pm_runtime_enable(dev->dev);
> >> pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT);
> >> pm_runtime_use_autosuspend(dev->dev);
> >> @@ -1130,7 +1128,21 @@ omap_i2c_probe(struct platform_device *pdev)
> >> if (IS_ERR_VALUE(r))
> >> goto err_free_mem;
> >>
> >> - dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
> >> + /* Read the Rev hi bit-14 ie scheme this is 1 indicates ver2 or
> >> + * highlander.
> > the "scheme" in highlander is a 2 bit value. In order to make this
> > future proof, you need to read both bits (31:30).
> Good point will fix it.
> >
> >> + * On omap3 Offset 4 is IE Reg the bit 14 is XDR_IE which is 0 at reset.
> >> + */
> > please align the * characters.
> yes will repost
> >
> >> + rev_hi = __raw_readw(dev->base + 0x04);
> > you should make omap_i2c_read_reg() work fine for this case too.
>
> Just felt it is more readlable this way also I didnt want to use the
> reg_shift etc.
>
> which also may get cleaned up sometime.
correct, but I think for now using omap_i2c_read_reg() is fine.
Maybe defining (for now) REV_HI and REV_LO on both reg_maps would do it?
Just for the time being until we can get rid of reg_shift and
omap_i2c_ip_version ??
I don't know, but to me using __raw_readl() with a hardcoded offset is a
bit odd.
--
balbi
signature.asc
Description: Digital signature
