Re: [PATCH 2/2] drm/vc4: Add DSI driver

From: Stephen Boyd
Date: Fri Jan 27 2017 - 15:24:19 EST


On 01/23, Eric Anholt wrote:
> +static int
> +vc4_dsi_init_phy_clocks(struct vc4_dsi *dsi)
> +{
> + struct device *dev = &dsi->pdev->dev;
> + const char *parent_name = __clk_get_name(dsi->pll_phy_clock);
> + static const struct {
> + const char *dsi0_name, *dsi1_name;
> + int div;
> + } phy_clocks[] = {
> + { "dsi0_byte", "dsi1_byte", 8 },
> + { "dsi0_ddr2", "dsi1_ddr2", 4 },
> + { "dsi0_ddr", "dsi1_ddr", 2 },
> + };
> + int i;
> +
> + dsi->clk_onecell.clk_num = ARRAY_SIZE(phy_clocks);
> + dsi->clk_onecell.clks = devm_kcalloc(dev,
> + dsi->clk_onecell.clk_num,
> + sizeof(*dsi->clk_onecell.clks),
> + GFP_KERNEL);
> + if (!dsi->clk_onecell.clks)
> + return -ENOMEM;
> +
> + for (i = 0; i < ARRAY_SIZE(phy_clocks); i++) {
> + struct clk_fixed_factor *fix = &dsi->phy_clocks[i];
> + struct clk_init_data init;
> + struct clk *clk;
> +
> + /* We just use core fixed factor clock ops for the PHY
> + * clocks. The clocks are actually gated by the
> + * PHY_AFEC0_DDRCLK_EN bits, which we should be
> + * setting if we use the DDR/DDR2 clocks. However,
> + * vc4_dsi_encoder_enable() is setting up both AFEC0,
> + * setting both our parent DSI PLL's rate and this
> + * clock's rate, so it knows if DDR/DDR2 are going to
> + * be used and could enable the gates itself.
> + */
> + fix->mult = 1;
> + fix->div = phy_clocks[i].div;
> + fix->hw.init = &init;
> +
> + memset(&init, 0, sizeof(init));
> + init.parent_names = &parent_name;
> + init.num_parents = 1;
> + if (dsi->port == 1)
> + init.name = phy_clocks[i].dsi1_name;
> + else
> + init.name = phy_clocks[i].dsi0_name;
> + init.ops = &clk_fixed_factor_ops;
> + init.flags = CLK_IS_BASIC;

Please don't use this flag unless you need it for something.

> +
> + clk = devm_clk_register(dev, &fix->hw);

Can you use devm_clk_hw_register() instead please?

> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + dsi->clk_onecell.clks[i] = clk;
> + }
> +
> + return of_clk_add_provider(dev->of_node,

And the of_clk_add_hw_provider() API too.

> + of_clk_src_onecell_get,
> + &dsi->clk_onecell);
> +}
> +

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