From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 2/6] dmaengine: sun6i: Add a quirk for additional mbus clock Date: Fri, 22 Mar 2019 14:03:25 +0100 Message-ID: <20190322130325.jomwzsntzwjt6zhj@flea> References: <20190307165829.9086-1-jernej.skrabec@siol.net> <20190307165829.9086-3-jernej.skrabec@siol.net> <20190316110753.GH5348@vkoul-mobl> <2451376.qVWA8nfu3q@jernej-laptop> <20190322125940.GE5348@vkoul-mobl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cx4t6dej4e6ikper" Return-path: Content-Disposition: inline In-Reply-To: <20190322125940.GE5348@vkoul-mobl> Sender: linux-kernel-owner@vger.kernel.org To: Vinod Koul Cc: Jernej =?utf-8?Q?=C5=A0krabec?= , wens@csie.org, robh+dt@kernel.org, mark.rutland@arm.com, dan.j.williams@intel.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com List-Id: devicetree@vger.kernel.org --cx4t6dej4e6ikper Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 22, 2019 at 06:29:40PM +0530, Vinod Koul wrote: > On 16-03-19, 12:23, Jernej =C5=A0krabec wrote: > > Hi! > > > > Dne sobota, 16. marec 2019 ob 12:07:53 CET je Vinod Koul napisal(a): > > > On 07-03-19, 17:58, Jernej Skrabec wrote: > > > > H6 DMA controller needs additional mbus clock to be enabled. > > > > > > > > Add a quirk for it and handle it accordingly. > > > > > > > > Signed-off-by: Jernej Skrabec > > > > --- > > > > > > > > drivers/dma/sun6i-dma.c | 23 ++++++++++++++++++++++- > > > > 1 file changed, 22 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > > > index 0cd13f17fc11..761555080325 100644 > > > > --- a/drivers/dma/sun6i-dma.c > > > > +++ b/drivers/dma/sun6i-dma.c > > > > @@ -129,6 +129,7 @@ struct sun6i_dma_config { > > > > > > > > u32 dst_burst_lengths; > > > > u32 src_addr_widths; > > > > u32 dst_addr_widths; > > > > > > > > + bool mbus_clk; > > > > > > > > }; > > > > > > > > /* > > > > > > > > @@ -182,6 +183,7 @@ struct sun6i_dma_dev { > > > > > > > > struct dma_device slave; > > > > void __iomem *base; > > > > struct clk *clk; > > > > > > > > + struct clk *clk_mbus; > > > > > > So rather than have mbus_clk and then a ptr, why not use the ptr and = use > > > NULL value to check for..? > > > > > > > I'm not sure what you mean here. clk_mbus will hold a reference to a cl= ock > > retrieved by devm_clk_get() so it has to be "struct clk *". > > > > What I'm missing here? > > IIRC there were two variable one clk ptr and one an integer to mark > presence, you may be able to skip variable and use ptr.. If we're doing that, then we would effectively make it optional. That DMA engine cannot operate without it. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --cx4t6dej4e6ikper Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXJTdDgAKCRDj7w1vZxhR xSbUAP9EeVKNwv86V4iEt039yt/IphxtO7I7GGSmGK6zrirNGAD9EwA3pUdJC38O NIazXox9JWvWXSr0N0gbAG+dlU3cRgQ= =8KMA -----END PGP SIGNATURE----- --cx4t6dej4e6ikper--