Re: [PATCH 04/19] clk: sunxi: Add TCON channel1 clock

From: Chen-Yu Tsai
Date: Sat Oct 31 2015 - 05:54:27 EST

On Fri, Oct 30, 2015 at 10:20 PM, Maxime Ripard
<maxime.ripard@xxxxxxxxxxxxxxxxxx> wrote:
> The TCON is a controller generating the timings to output videos signals,
> acting like both a CRTC and an encoder.
>
> It has two channels depending on the output, each channel being driven by
> its own clock (and own clock controller).
>
> Add a driver for the channel 1 clock.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/clk/sunxi/Makefile | 1 +
> drivers/clk/sunxi/clk-sun4i-tcon-ch1.c | 167 +++++++++++++++++++++++++++++++++
> 2 files changed, 168 insertions(+)
> create mode 100644 drivers/clk/sunxi/clk-sun4i-tcon-ch1.c

According to the documents I have, this variant of the TCON clock
is specific to sun5i. On sun4i/sun7i, TCON CH1 clock has the same
layout as TCON CH0 and the other display clocks.

>
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index 7821b2b63d58..ed59ee4b3a85 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -13,6 +13,7 @@ obj-y += clk-simple-gates.o
> obj-y += clk-sun4i-display.o
> obj-y += clk-sun4i-pll3.o
> obj-y += clk-sun4i-tcon-ch0.o
> +obj-y += clk-sun4i-tcon-ch1.o
> obj-y += clk-sun8i-mbus.o
> obj-y += clk-sun9i-core.o
> obj-y += clk-sun9i-mmc.o
> diff --git a/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
> new file mode 100644
> index 000000000000..9f2ab52b0bf9
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-sun4i-tcon-ch1.c
> @@ -0,0 +1,167 @@
> +/*
> + * Copyright 2015 Maxime Ripard
> + *
> + * Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +#define SUN4I_TCON_CH1_SCLK_NAME_LEN 32
> +
> +#define SUN4I_A10_TCON_CH1_SCLK1_PARENTS 2
> +#define SUN4I_A10_TCON_CH1_SCLK2_PARENTS 4
> +
> +#define SUN4I_A10_TCON_CH1_SCLK2_GATE_BIT 31
> +#define SUN4I_A10_TCON_CH1_SCLK2_MUX_MASK 3
> +#define SUN4I_A10_TCON_CH1_SCLK2_MUX_SHIFT 24
> +#define SUN4I_A10_TCON_CH1_SCLK2_DIV_WIDTH 4
> +#define SUN4I_A10_TCON_CH1_SCLK2_DIV_SHIFT 0
> +
> +#define SUN4I_A10_TCON_CH1_SCLK1_GATE_BIT 15
> +#define SUN4I_A10_TCON_CH1_SCLK1_MUX_MASK 1
> +#define SUN4I_A10_TCON_CH1_SCLK1_MUX_SHIFT 11
> +
> +static DEFINE_SPINLOCK(sun4i_a10_tcon_ch1_lock);
> +
> +static void __init sun4i_a10_tcon_ch1_setup(struct device_node *node)
> +{
> + const char *sclk1_parents[SUN4I_A10_TCON_CH1_SCLK1_PARENTS];
> + const char *sclk2_parents[SUN4I_A10_TCON_CH1_SCLK2_PARENTS];
> + const char *sclk1_name = node->name;
> + char sclk2_name[SUN4I_TCON_CH1_SCLK_NAME_LEN];
> + char sclk2d2_name[SUN4I_TCON_CH1_SCLK_NAME_LEN];
> + struct clk_gate *sclk1_gate, *sclk2_gate;
> + struct clk_mux *sclk1_mux, *sclk2_mux;
> + struct clk *sclk1, *sclk2, *sclk2d2;
> + struct clk_divider *sclk2_div;
> + void __iomem *reg;
> + int i;
> +
> + of_property_read_string(node, "clock-output-names",
> + &sclk1_name);
> +
> + snprintf(sclk2_name, SUN4I_TCON_CH1_SCLK_NAME_LEN,
> + "%s2", sclk1_name);
> +
> + snprintf(sclk2d2_name, SUN4I_TCON_CH1_SCLK_NAME_LEN,
> + "%s2d2", sclk1_name);
> +
> + reg = of_io_request_and_map(node, 0, of_node_full_name(node));
> + if (IS_ERR(reg)) {
> + pr_err("%s: Could not map the clock registers\n", sclk2_name);
> + return;
> + }
> +
> + for (i = 0; i < SUN4I_A10_TCON_CH1_SCLK2_PARENTS; i++)
> + sclk2_parents[i] = of_clk_get_parent_name(node, i);
> +
> + sclk2_mux = kzalloc(sizeof(*sclk2_mux), GFP_KERNEL);
> + if (!sclk2_mux)
> + return;
> +
> + sclk2_mux->reg = reg;
> + sclk2_mux->shift = SUN4I_A10_TCON_CH1_SCLK2_MUX_SHIFT;
> + sclk2_mux->mask = SUN4I_A10_TCON_CH1_SCLK2_MUX_MASK;
> + sclk2_mux->lock = &sun4i_a10_tcon_ch1_lock;
> +
> + sclk2_gate = kzalloc(sizeof(*sclk2_gate), GFP_KERNEL);
> + if (!sclk2_gate)
> + goto free_sclk2_mux;
> +
> + sclk2_gate->reg = reg;
> + sclk2_gate->bit_idx = SUN4I_A10_TCON_CH1_SCLK2_GATE_BIT;
> + sclk2_gate->lock = &sun4i_a10_tcon_ch1_lock;
> +
> + sclk2_div = kzalloc(sizeof(*sclk2_div), GFP_KERNEL);
> + if (!sclk2_div)
> + goto free_sclk2_gate;
> +
> + sclk2_div->reg = reg;
> + sclk2_div->shift = SUN4I_A10_TCON_CH1_SCLK2_DIV_SHIFT;
> + sclk2_div->width = SUN4I_A10_TCON_CH1_SCLK2_DIV_WIDTH;
> + sclk2_div->lock = &sun4i_a10_tcon_ch1_lock;
> +
> + sclk2 = clk_register_composite(NULL, sclk2_name, sclk2_parents,
> + SUN4I_A10_TCON_CH1_SCLK2_PARENTS,
> + &sclk2_mux->hw, &clk_mux_ops,
> + &sclk2_div->hw, &clk_divider_ops,
> + &sclk2_gate->hw, &clk_gate_ops,
> + 0);
> + if (IS_ERR(sclk2)) {
> + pr_err("%s: Couldn't register the clock\n", sclk2_name);
> + goto free_sclk2_div;
> + }
> +
> + sclk2d2 = clk_register_fixed_factor(NULL, sclk2d2_name, sclk2_name, 0,
> + 1, 2);
> + if (IS_ERR(sclk2d2)) {
> + pr_err("%s: Couldn't register the clock\n", sclk2d2_name);
> + goto free_sclk2;
> + }
> +
> + sclk1_parents[0] = sclk2_name;
> + sclk1_parents[1] = sclk2d2_name;

Is there any need to expose these 2 clocks via DT using of_clk_add_provider?

Note that these complex clock trees within a clock node breaks the
assigned-clock-parents mechanism, as you can no longer specify the output
clock's direct parents.


Regards
ChenYu

> +
> + sclk1_mux = kzalloc(sizeof(*sclk1_mux), GFP_KERNEL);
> + if (!sclk1_mux)
> + goto free_sclk2d2;
> +
> + sclk1_mux->reg = reg;
> + sclk1_mux->shift = SUN4I_A10_TCON_CH1_SCLK1_MUX_SHIFT;
> + sclk1_mux->mask = SUN4I_A10_TCON_CH1_SCLK1_MUX_MASK;
> + sclk1_mux->lock = &sun4i_a10_tcon_ch1_lock;
> +
> + sclk1_gate = kzalloc(sizeof(*sclk1_gate), GFP_KERNEL);
> + if (!sclk1_gate)
> + goto free_sclk1_mux;
> +
> + sclk1_gate->reg = reg;
> + sclk1_gate->bit_idx = SUN4I_A10_TCON_CH1_SCLK1_GATE_BIT;
> + sclk1_gate->lock = &sun4i_a10_tcon_ch1_lock;
> +
> + sclk1 = clk_register_composite(NULL, sclk1_name, sclk1_parents,
> + SUN4I_A10_TCON_CH1_SCLK1_PARENTS,
> + &sclk1_mux->hw, &clk_mux_ops,
> + NULL, NULL,
> + &sclk1_gate->hw, &clk_gate_ops,
> + 0);
> + if (IS_ERR(sclk1)) {
> + pr_err("%s: Couldn't register the clock\n", sclk1_name);
> + goto free_sclk1_gate;
> + }
> +
> + of_clk_add_provider(node, of_clk_src_simple_get, sclk1);
> +
> + return;
> +
> +free_sclk1_gate:
> + kfree(sclk1_gate);
> +free_sclk1_mux:
> + kfree(sclk1_mux);
> +free_sclk2d2:
> + clk_unregister(sclk2d2);
> +free_sclk2:
> + clk_unregister(sclk2);
> +free_sclk2_div:
> + kfree(sclk2_div);
> +free_sclk2_gate:
> + kfree(sclk2_gate);
> +free_sclk2_mux:
> + kfree(sclk2_mux);
> +}
> +
> +CLK_OF_DECLARE(sun4i_a10_tcon_ch1, "allwinner,sun4i-a10-tcon-ch1-clk",
> + sun4i_a10_tcon_ch1_setup);
> --
> 2.6.2
>
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