Re: [PATCH v2 5/7] dmaengine: sun6i: Add support for H6 DMA

From: Maxime Ripard <maxime.ripard@bootlin.com>
To: "Clément Péron" <peron.clem@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	devicetree <devicetree@vger.kernel.org>,
	Jernej Skrabec <jernej.skrabec@siol.net>,
	Chen-Yu Tsai <wens@csie.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Vinod Koul <vkoul@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	dmaengine@vger.kernel.org,
	Dan Williams <dan.j.williams@intel.com>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 5/7] dmaengine: sun6i: Add support for H6 DMA
Date: Mon, 27 May 2019 14:49:19 +0200	[thread overview]
Message-ID: <20190527124919.wmdlqrhv4xw6iabi@flea> (raw)
In-Reply-To: <CAJiuCcfe7LHehZTzGvW+0LzqvDRs4dSjmGhRxkDHgbHrD2+MKA@mail.gmail.com>


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On Sun, May 26, 2019 at 09:12:36PM +0200, Clément Péron wrote:
> Hi Maxime,
>
> On Sun, 26 May 2019 at 20:34, Maxime Ripard <maxime.ripard@bootlin.com> wrote:
> >
> > On Sat, May 25, 2019 at 06:38:17PM +0200, Clément Péron wrote:
> > > From: Jernej Skrabec <jernej.skrabec@siol.net>
> > >
> > > H6 DMA has more than 32 supported DRQs, which means that configuration
> > > register is slightly rearranged. It also needs additional clock to be
> > > enabled.
> > >
> > > Add support for it.
> > >
> > > Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
> > > Signed-off-by: Clément Péron <peron.clem@gmail.com>
> > > ---
> > >  drivers/dma/sun6i-dma.c | 44 +++++++++++++++++++++++++++++++++++++++--
> > >  1 file changed, 42 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
> > > index f5cb5e89bf7b..8d44ddae926a 100644
> > > --- a/drivers/dma/sun6i-dma.c
> > > +++ b/drivers/dma/sun6i-dma.c
> > > @@ -69,14 +69,19 @@
> > >
> > >  #define DMA_CHAN_CUR_CFG     0x0c
> > >  #define DMA_CHAN_MAX_DRQ_A31         0x1f
> > > +#define DMA_CHAN_MAX_DRQ_H6          0x3f
> > >  #define DMA_CHAN_CFG_SRC_DRQ_A31(x)  ((x) & DMA_CHAN_MAX_DRQ_A31)
> > > +#define DMA_CHAN_CFG_SRC_DRQ_H6(x)   ((x) & DMA_CHAN_MAX_DRQ_H6)
> > >  #define DMA_CHAN_CFG_SRC_MODE_A31(x) (((x) & 0x1) << 5)
> > > +#define DMA_CHAN_CFG_SRC_MODE_H6(x)  (((x) & 0x1) << 8)
> > >  #define DMA_CHAN_CFG_SRC_BURST_A31(x)        (((x) & 0x3) << 7)
> > >  #define DMA_CHAN_CFG_SRC_BURST_H3(x) (((x) & 0x3) << 6)
> > >  #define DMA_CHAN_CFG_SRC_WIDTH(x)    (((x) & 0x3) << 9)
> > >
> > >  #define DMA_CHAN_CFG_DST_DRQ_A31(x)  (DMA_CHAN_CFG_SRC_DRQ_A31(x) << 16)
> > > +#define DMA_CHAN_CFG_DST_DRQ_H6(x)   (DMA_CHAN_CFG_SRC_DRQ_H6(x) << 16)
> > >  #define DMA_CHAN_CFG_DST_MODE_A31(x) (DMA_CHAN_CFG_SRC_MODE_A31(x) << 16)
> > > +#define DMA_CHAN_CFG_DST_MODE_H6(x)  (DMA_CHAN_CFG_SRC_MODE_H6(x) << 16)
> > >  #define DMA_CHAN_CFG_DST_BURST_A31(x)        (DMA_CHAN_CFG_SRC_BURST_A31(x) << 16)
> > >  #define DMA_CHAN_CFG_DST_BURST_H3(x) (DMA_CHAN_CFG_SRC_BURST_H3(x) << 16)
> > >  #define DMA_CHAN_CFG_DST_WIDTH(x)    (DMA_CHAN_CFG_SRC_WIDTH(x) << 16)
> > > @@ -319,12 +324,24 @@ static void sun6i_set_drq_a31(u32 *p_cfg, s8 src_drq, s8 dst_drq)
> > >                 DMA_CHAN_CFG_DST_DRQ_A31(dst_drq);
> > >  }
> > >
> > > +static void sun6i_set_drq_h6(u32 *p_cfg, s8 src_drq, s8 dst_drq)
> > > +{
> > > +     *p_cfg |= DMA_CHAN_CFG_SRC_DRQ_H6(src_drq) |
> > > +               DMA_CHAN_CFG_DST_DRQ_H6(dst_drq);
> > > +}
> > > +
> > >  static void sun6i_set_mode_a31(u32 *p_cfg, s8 src_mode, s8 dst_mode)
> > >  {
> > >       *p_cfg |= DMA_CHAN_CFG_SRC_MODE_A31(src_mode) |
> > >                 DMA_CHAN_CFG_DST_MODE_A31(dst_mode);
> > >  }
> > >
> > > +static void sun6i_set_mode_h6(u32 *p_cfg, s8 src_mode, s8 dst_mode)
> > > +{
> > > +     *p_cfg |= DMA_CHAN_CFG_SRC_MODE_H6(src_mode) |
> > > +               DMA_CHAN_CFG_DST_MODE_H6(dst_mode);
> > > +}
> > > +
> > >  static size_t sun6i_get_chan_size(struct sun6i_pchan *pchan)
> > >  {
> > >       struct sun6i_desc *txd = pchan->desc;
> > > @@ -1160,6 +1177,28 @@ static struct sun6i_dma_config sun50i_a64_dma_cfg = {
> > >                            BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
> > >  };
> > >
> > > +/*
> > > + * The H6 binding uses the number of dma channels from the
> > > + * device tree node.
> > > + */
> > > +static struct sun6i_dma_config sun50i_h6_dma_cfg = {
> > > +     .clock_autogate_enable = sun6i_enable_clock_autogate_h3,
> > > +     .set_burst_length = sun6i_set_burst_length_h3,
> > > +     .set_drq          = sun6i_set_drq_h6,
> > > +     .set_mode         = sun6i_set_mode_h6,
> > > +     .src_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
> > > +     .dst_burst_lengths = BIT(1) | BIT(4) | BIT(8) | BIT(16),
> > > +     .src_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
> > > +     .dst_addr_widths   = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
> > > +                          BIT(DMA_SLAVE_BUSWIDTH_8_BYTES),
> > > +     .has_mbus_clk = true,
> > > +};
> > > +
> > >  /*
> > >   * The V3s have only 8 physical channels, a maximum DRQ port id of 23,
> > >   * and a total of 24 usable source and destination endpoints.
> > > @@ -1190,6 +1229,7 @@ static const struct of_device_id sun6i_dma_match[] = {
> > >       { .compatible = "allwinner,sun8i-h3-dma", .data = &sun8i_h3_dma_cfg },
> > >       { .compatible = "allwinner,sun8i-v3s-dma", .data = &sun8i_v3s_dma_cfg },
> > >       { .compatible = "allwinner,sun50i-a64-dma", .data = &sun50i_a64_dma_cfg },
> > > +     { .compatible = "allwinner,sun50i-h6-dma", .data = &sun50i_h6_dma_cfg },
> > >       { /* sentinel */ }
> > >  };
> > >  MODULE_DEVICE_TABLE(of, sun6i_dma_match);
> > > @@ -1288,8 +1328,8 @@ static int sun6i_dma_probe(struct platform_device *pdev)
> > >       ret = of_property_read_u32(np, "dma-requests", &sdc->max_request);
> > >       if (ret && !sdc->max_request) {
> > >               dev_info(&pdev->dev, "Missing dma-requests, using %u.\n",
> > > -                      DMA_CHAN_MAX_DRQ_A31);
> > > -             sdc->max_request = DMA_CHAN_MAX_DRQ_A31;
> > > +                      DMA_CHAN_MAX_DRQ_H6);
> > > +             sdc->max_request = DMA_CHAN_MAX_DRQ_H6;
> >
> > This is changing the binding though, since we're changing the
> > default. This should be reflected in the binding, and we should keep
> > the same default in the device tree binding.
>
> Agree, H6 device-tree will have the "dma-request" property.
> As this modification is not mandatory, we can drop it to avoid
> bindings modification.
>
> What do you think?

That works for me

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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