Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1470990
| Path | csiph.com!news.mixmin.net!news.unit0.net!news.panservice.it!bofh.it!news.nic.it!robomod |
|---|---|
| From | Maxime Ripard <maxime.ripard@free-electrons.com> |
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver |
| Date | Fri, 26 Aug 2016 23:00:01 +0200 |
| Message-ID | <sawoh-3ze-5@gated-at.bofh.it> (permalink) |
| References | <rWUJP-7jB-7@gated-at.bofh.it> <rWUJP-7jB-17@gated-at.bofh.it> <rYUcF-f6-19@gated-at.bofh.it> <s9H2q-3m5-9@gated-at.bofh.it> |
| MIME-Version | 1.0 |
| Content-Type | multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BI5RvnYi6R4T2M87" |
| Content-Disposition | inline |
| User-Agent | Mutt/1.5.24 (2015-08-30) |
| Sender | robomod@news.nic.it |
| List-ID | <linux-kernel.vger.kernel.org> |
| X-Mailing-List | linux-kernel@vger.kernel.org |
| Approved | robomod@news.nic.it |
| Lines | 74 |
| Organization | linux.* mail to news gateway |
| X-Original-Cc | robh+dt@kernel.org, mark.rutland@arm.com, wens@csie.org, linux@armlinux.org.uk, davem@davemloft.net, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com |
| X-Original-Date | Fri, 26 Aug 2016 22:49:14 +0200 |
| X-Original-Message-ID | <20160826204914.GD3165@lukather> |
| X-Original-References | <1469001800-11615-1-git-send-email-clabbe.montjoie@gmail.com> <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> <20160725195455.GQ7419@lukather> <20160824120221.GB29212@Red> |
| X-Original-Sender | linux-kernel-owner@vger.kernel.org |
| Xref | csiph.com linux.kernel:1470990 |
Show key headers only | View raw
[Multipart message — attachments visible in raw view] - view raw
Hi,
On Wed, Aug 24, 2016 at 02:02:21PM +0200, LABBE Corentin wrote:
> > > +/* Set Management Data Clock, must be call after device reset */
> > > +static void sun8i_emac_set_mdc(struct net_device *ndev)
> > > +{
> > > + struct sun8i_emac_priv *priv = netdev_priv(ndev);
> > > + unsigned long rate;
> > > + u32 reg;
> > > +
> > > + rate = clk_get_rate(priv->ahb_clk);
> > > + if (rate > 160000000)
> > > + reg = 0x3 << 20; /* AHB / 128 */
> > > + else if (rate > 80000000)
> > > + reg = 0x2 << 20; /* AHB / 64 */
> > > + else if (rate > 40000000)
> > > + reg = 0x1 << 20; /* AHB / 32 */
> > > + else
> > > + reg = 0x0 << 20; /* AHB / 16 */
> > > + netif_dbg(priv, link, ndev, "MDC auto : %x\n", reg);
> > > + writel(reg, priv->base + SUN8I_EMAC_MDIO_CMD);
> >
> > You could also expose that as a clock.
> >
>
> For which purpose ?
> No ethernet driver expose the MDC as clock and I dont see any interest:
> - I dont think that tuning it give any gain
> - Knowing it's value is of little interest
You don't have to implement anything, you can just register a clk_div
driver, and everything works, and you would use the proper clock APIs
(ie. clk_set_rate, and that's it).
That would be exposed just like any other clock, including in debugfs,
which would remove the need for the debug call.
But this really was just a suggestion.
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
Back to linux.kernel | Previous | Next | Find similar | Unroll thread
Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-08-26 23:00 +0200
csiph-web