From: Heiko Stuebner <heiko@sntech.de>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Wen Nuan <leo.wen@rock-chips.com>,
David Wu <david.wu@rock-chips.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Greg KH <gregkh@linuxfoundation.org>,
Randy Dunlap <rdunlap@infradead.org>,
jacob2.chen@rock-chips.com,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-media@vger.kernel.org, Eddie Cai <eddie.cai@rock-chips.com>
Subject: Re: [PATCH V2 1/2] [media] Add Rockchip RK1608 driver
Date: Mon, 26 Feb 2018 16:15:44 +0100 [thread overview]
Message-ID: <3613277.0XuNfbW5nk@phil> (raw)
In-Reply-To: <CACRpkdZDWvqrpop9FaJUidJjR8jB=Db-WztePrqKSg5Yp5gvCA@mail.gmail.com>
Hi Linus,
thanks for catching these things :-) .
Am Montag, 26. Februar 2018, 11:12:30 CET schrieb Linus Walleij:
> On Mon, Feb 26, 2018 at 9:16 AM, Wen Nuan <leo.wen@rock-chips.com> wrote:
> > + pdata->grf_gpio2b_iomux = ioremap((resource_size_t)
> > + (GRF_BASE_ADDR +
> > + GRF_GPIO2B_IOMUX), 4);
> > + grf_val = __raw_readl(pdata->grf_gpio2b_iomux);
> > + __raw_writel(((grf_val) | (1 << 6) | (1 << (6 + 16))),
> > + pdata->grf_gpio2b_iomux);
> > +
> > + pdata->grf_io_vsel = ioremap((resource_size_t)
> > + (GRF_BASE_ADDR + GRF_IO_VSEL), 4);
> > + grf_val = __raw_readl(pdata->grf_io_vsel);
> > + __raw_writel(((grf_val) | (1 << 1) | (1 << (1 + 16))),
> > + pdata->grf_io_vsel);
>
> You are doing pin control on the side of the pin control subsystem
> it looks like?
>
> I think David Wu and Heiko Stubner needs to have a look at what you
> are doing here to suggest other solutions.
Especially as the rk1608 seems to be some a spi-connected peripheral.
So it should definitly not touch _any_ soc-specific registers at all.
I just looked up the patch in patchwork and apart from the one Linus
quoted above, I found quite a bit more open-coded pinctrl settings
as well as direct writes to the clock controller and even io-voltage
selections.
All these things are highly soc-specific so vary with each soc this
ic gets connected to and the kernel does provide abstractions for
all of them. For clock-rates there are the clock-apis and also
the assigned-clock* properties for the devicetree, pinctrl supports
multiple states and io-vsel selections normally should just monitor
the supply-regulator via the io-domain driver we already have
[See vqmmc handling in for sd-cards for example].
So this driver should not touch anything of that sort and therefore
should _not_ contain any iomem-based read or write at all.
Heiko
next prev parent reply other threads:[~2018-02-26 15:15 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 8:16 [PATCH V2 0/2] Rockchip: Add RK1608 driver and DT-bindings Wen Nuan
2018-02-26 8:16 ` [PATCH V2 1/2] [media] Add Rockchip RK1608 driver Wen Nuan
2018-02-26 9:50 ` Hans Verkuil
2018-02-26 10:12 ` Linus Walleij
2018-02-26 15:15 ` Heiko Stuebner [this message]
2018-02-27 3:15 ` 温暖
2018-02-27 15:12 ` Heiko Stuebner
2018-02-28 1:23 ` 回复: " 温暖
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