Re: [PATCH] hw_random: rockchip: import driver from vendor tree

From: LABBE Corentin <clabbe@baylibre.com>
To: Robin Murphy <robin.murphy@arm.com>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Lin Jinhan <troy.lin@rock-chips.com>, wevsty <ty@wevs.org>,
	Mikhail Rudenko <mike.rudenko@gmail.com>,
	Heiko Stuebner <heiko@sntech.de>, Lin Huang <hl@rock-chips.com>,
	Shawn Lin <shawn.lin@rock-chips.com>,
	linux-rockchip@lists.infradead.org
Subject: Re: [PATCH] hw_random: rockchip: import driver from vendor tree
Date: Thu, 29 Sep 2022 09:45:09 +0200	[thread overview]
Message-ID: <YzVNBcF7TCDldPwF@Red> (raw)
In-Reply-To: <YzNthZ0MtfwjIqdH@aurel32.net>

Le Tue, Sep 27, 2022 at 11:39:17PM +0200, Aurelien Jarno a écrit :
> On 2022-09-27 21:46, LABBE Corentin wrote:
> > Le Tue, Sep 27, 2022 at 06:37:53PM +0200, Aurelien Jarno a écrit :
> > > On 2022-09-20 10:35, Robin Murphy wrote:
> > > > On 2022-09-19 22:00, Jason A. Donenfeld wrote:
> > > > > The Rockchip driver has long existed out of tree, but not upstream.
> > > > > There is support for it upstream in u-boot, but not in Linux proper.
> > > > > This commit imports the GPLv2 driver written by Lin Jinhan, together
> > > > > with the DTS and config blobs from Wevsty.
> > > > 
> > > > Note that Corentin has a series enabling the full crypto driver for 
> > > > RK3328 and RK3399[1], so it would seem more sensible to add TRNG support 
> > > > to that. Having confliciting compatibles for the same hardware that 
> > > > force the user to change their DT to choose one functionality or the 
> > > > other isn't good (plus there's also no binding for this one).
> > > 
> > > It might make sense for the cryptov1-rng driver (I haven't checked). For
> > > the cryptov2-rng driver, I looked at the RK3568 TRM (I can't find the
> > > RK3588 one), and from what I understand crypto and TRNG are two
> > > different devices, using different address spaces, clock, reset and
> > > interrupts. The vendor kernel uses two different drivers.
> > > 
> > 
> > I confirm that TRNG is not on the same IP on rk3568, something I didnt remark when doing my V2 driver. (I need to remove rng clock from rk3568 dt).
> > But the rk3588 crypto IP and the TRNG are in the same device.
> 
> Ok, thanks for confirming about the rk3568. It seems the only one in the
> family with separate devices for TRNG and crypto. Does it means we need
> a separate TRNG driver only for it? Or could we handle it the same way
> than for instance rk3588 anyway?

I just got now the part 1 of rk3588 TRM which I has missing and it show some conflicting information.
rk3588 seems to have both a dedicated TRNG (TRNG_NS/TRNG_S) with dedicated address space and a TRNG inside the crypto IP.
But for the moment, the TRNG inside crypto IP seems defective.