# RE: \[PATCH\] powerpc/fsl: mpic timer driver

- From: Wang Dongsheng-B40534 \<hidden\>
- Date: 2012-07-31 07:58:52 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2012/07/9470577
- Thread: https://ratatoskr.run/linuxppc-dev/2012/07/9470537/t.md

```text


> -----Original Message-----
> From: Kumar Gala [mailto:<redacted>]
> Sent: Friday, July 27, 2012 9:14 PM
> To: Wang Dongsheng-B40534
> Cc: benh@kernel.crashing.org; <redacted>; Wood Scott-B07421;
> linuxppc-dev@lists.ozlabs.org
> Subject: Re: [PATCH] powerpc/fsl: mpic timer driver
>=20
>=20
> On Jul 27, 2012, at 1:20 AM, [ref]
> [ref] wrote:
>=20
> > From: Wang Dongsheng <redacted>
> >
> > Global timers A and B internal to the PIC. The two independent groups
> > of global timer, group A and group B, are identical in their
> functionality.
> > The hardware timer generates an interrupt on every timer cycle.
> > e.g
> > Power management can use the hardware timer to wake up the machine.
> >
> > Signed-off-by: Wang Dongsheng <redacted>
> > Signed-off-by: Li Yang <redacted>
>=20
> How much of this is FSL specific vs openpic?  OpenPIC spec's timer
> support (only a single group).
>=20
[Wang Dongsheng] Yes, OpenPIC only a single group timer.
FSL: add more register, features and group.
This patch only to support FSL chip.
"mpic_timer.c" -> "fsl_mpic_timer.c"
I will modify the description of the patch. how about?

 > > +static int set_cascade_timer(struct group_priv *priv, u64 ticks,
> > +		unsigned int num)
> > +{
> > +	struct cascade_priv *casc_priv;
> > +	u32 tmp;
> > +	u32 tmp_ticks;
> > +	u32 rem_ticks;
> > +
> > +	/* set group tcr reg for cascade */
> > +	casc_priv =3D priv->timer[num].cascade_handle;
> > +	if (!casc_priv)
> > +		return -EINVAL;
> > +
> > +	tmp =3D casc_priv->tcr_value |
> > +		(casc_priv->tcr_value << MPIC_TIMER_TCR_ROVR_OFFSET);
> > +	setbits32(priv->group_tcr, tmp);
> > +
> > +	tmp_ticks =3D div_u64_rem(ticks, MAX_TIME_CASCADE, &rem_ticks);
> > +
> > +	out_be32(&priv->regs[num].gtccr, 0);
> > +	out_be32(&priv->regs[num].gtbcr, tmp_ticks | MPIC_TIMER_STOP);
> > +
> > +	out_be32(&priv->regs[num - 1].gtccr, 0);
> > +	out_be32(&priv->regs[num - 1].gtbcr, rem_ticks);
> > +
> > +	return 0;
> > +}
> > +
> > +struct mpic_timer *get_cascade_timer(u64 ticks) {
>=20
> should this be static?
>=20
[Wang Dongsheng] ok.

> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev@lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/linuxppc-dev
>=20
```