[PATCH RFC 1/2] clk: sunxi: Add sun8i display support
Maxime Ripard
maxime.ripard at free-electrons.com
Mon Jan 18 11:09:04 PST 2016
Hi,
On Tue, Jan 05, 2016 at 07:28:25PM +0100, Jean-Francois Moine wrote:
> Add the clock types which are used by the sun8i family for video.
>
> Signed-off-by: Jean-Francois Moine <moinejf at free.fr>
> ---
> drivers/clk/sunxi/Makefile | 1 +
> drivers/clk/sunxi/clk-sun8i-display.c | 247 ++++++++++++++++++++++++++++++++++
> 2 files changed, 258 insertions(+)
> create mode 100644 drivers/clk/sunxi/clk-sun8i-display.c
>
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> index cb4c299..145c078 100644
> --- a/drivers/clk/sunxi/Makefile
> +++ b/drivers/clk/sunxi/Makefile
> @@ -10,6 +10,7 @@ obj-y += clk-a10-pll2.o
> obj-y += clk-a20-gmac.o
> obj-y += clk-mod0.o
> obj-y += clk-simple-gates.o
> +obj-y += clk-sun8i-display.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-sun8i-display.c b/drivers/clk/sunxi/clk-sun8i-display.c
> new file mode 100644
> index 0000000..eded572
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-sun8i-display.c
> @@ -0,0 +1,247 @@
> +/*
> + * Copyright 2015 Jean-Francois Moine <moinejf at free.fr>
> + *
> + * 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>
> +#include <linux/rational.h>
> +#include <linux/delay.h>
> +
> +static DEFINE_SPINLOCK(sun8i_display_lock);
> +
> +/* PLL3 (video) and PLL10 (de) */
> +struct clk_fact {
> + struct clk_hw hw;
> + void __iomem *reg;
> +};
> +#define to_clk_fact(_hw) container_of(_hw, struct clk_fact, hw)
> +
> +#define SUN8I_PLL3_MSHIFT 0
> +#define SUN8I_PLL3_MMASK 0x0f
> +#define SUN8I_PLL3_NSHIFT 8
> +#define SUN8I_PLL3_NMASK 0x7f
> +#define SUN8I_PLL3_MODE_SEL 0x01000000
> +#define SUN8I_PLL3_FRAC_CLK 0x02000000
> +
> +static int sun8i_pll3_get_fact(unsigned long rate,
> + unsigned long parent_rate,
> + unsigned long *n, unsigned long *m)
> +{
> + if (rate == 297000000)
> + return 1;
> + if (rate == 270000000)
> + return 0;
> + rational_best_approximation(rate, parent_rate,
> + SUN8I_PLL3_NMASK + 1, SUN8I_PLL3_MMASK + 1,
> + n, m);
> + return -1;
> +}
> +
> +static unsigned long sun8i_pll3_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct clk_fact *fact = to_clk_fact(hw);
> + u32 reg;
> + u32 n, m;
> +
> + reg = readl(fact->reg);
> + if (reg & SUN8I_PLL3_MODE_SEL) {
> + n = (reg >> SUN8I_PLL3_NSHIFT) & SUN8I_PLL3_NMASK;
> + m = (reg >> SUN8I_PLL3_MSHIFT) & SUN8I_PLL3_MMASK;
> + return parent_rate / (m + 1) * (n + 1);
> + }
> + if (reg & SUN8I_PLL3_FRAC_CLK)
> + return 297000000;
> + return 270000000;
> +}
> +
> +static long sun8i_pll3_round_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long *parent_rate)
> +{
> + int frac;
> + unsigned long n, m;
> +
> + frac = sun8i_pll3_get_fact(rate, *parent_rate, &n, &m);
> + if (frac == 1)
> + return 297000000;
> + if (frac == 0)
> + return 270000000;
> + return (*parent_rate * n) / m;
> +}
> +
> +static int sun8i_pll3_set_rate(struct clk_hw *hw, unsigned long rate,
> + unsigned long parent_rate)
> +{
> + struct clk_fact *fact = to_clk_fact(hw);
> + u32 reg;
> + int frac;
> + unsigned long n, m;
> +
> + reg = readl(fact->reg) &
> + ~(SUN8I_PLL3_MODE_SEL |
> + SUN8I_PLL3_FRAC_CLK |
> + (SUN8I_PLL3_NMASK << SUN8I_PLL3_NSHIFT) |
> + (SUN8I_PLL3_MMASK << SUN8I_PLL3_MSHIFT));
> +
> + frac = sun8i_pll3_get_fact(rate, parent_rate, &n, &m);
> + if (frac == 1)
> + reg |= SUN8I_PLL3_FRAC_CLK; /* 297MHz */
> + else if (frac == 0)
> + ; /* 270MHz */
> + else
> + reg |= SUN8I_PLL3_MODE_SEL |
> + ((n - 1) << SUN8I_PLL3_NSHIFT) |
> + ((m - 1) << SUN8I_PLL3_MSHIFT);
> +
> + writel(reg, fact->reg);
> +
> + /* delay 500us so pll stabilizes */
> + __delay(500);
> +
> + return 0;
> +}
> +
> +static const struct clk_ops clk_sun8i_pll3_fact_ops = {
> + .recalc_rate = sun8i_pll3_recalc_rate,
> + .round_rate = sun8i_pll3_round_rate,
> + .set_rate = sun8i_pll3_set_rate,
> +};
We have the clk-factors stuff to handle this easily, could you use
that instead ?
> +
> +static void __init sun8i_pll3_setup(struct device_node *node)
> +{
> + const char *clk_name = node->name, *parent;
> + struct clk_fact *fact;
> + struct clk_gate *gate;
> + void __iomem *reg;
> + struct clk *clk;
> +
> + of_property_read_string(node, "clock-output-names", &clk_name);
> + parent = of_clk_get_parent_name(node, 0);
> +
> + 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", clk_name);
> + return;
> + }
> +
> + gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> + if (!gate)
> + return;
> +
> + gate->reg = reg;
> + gate->bit_idx = 31;
> + gate->lock = &sun8i_display_lock;
> +
> + fact = kzalloc(sizeof(*fact), GFP_KERNEL);
> + if (!fact)
> + goto free_gate;
> +
> + fact->reg = reg;
> +
> + clk = clk_register_composite(NULL, clk_name,
> + &parent, 1,
> + NULL, NULL,
> + &fact->hw, &clk_sun8i_pll3_fact_ops,
> + &gate->hw, &clk_gate_ops,
> + 0);
> + if (IS_ERR(clk)) {
> + pr_err("%s: Couldn't register the clock\n", clk_name);
> + goto free_fact;
> + }
> +
> + of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +
> + return;
> +
> +free_fact:
> + kfree(fact);
> +free_gate:
> + kfree(gate);
> +}
> +
> +CLK_OF_DECLARE(sun8i_pll3, "allwinner,sun8i-pll3-clk", sun8i_pll3_setup);
> +
> +/* DE, TCON0, TVE, HDMI, DEINTERLACE */
> +static void __init sun8i_display_setup(struct device_node *node)
> +{
> + const char *clk_name = node->name;
> + const char *parents[2];
> + struct clk_mux *mux = NULL;
> + struct clk_divider *div;
> + struct clk_gate *gate;
> + void __iomem *reg;
> + struct clk *clk;
> + int n;
> +
> + of_property_read_string(node, "clock-output-names", &clk_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", clk_name);
> + return;
> + }
> +
> + n = of_clk_parent_fill(node, parents, ARRAY_SIZE(parents));
> +
> + if (n > 1) { /* many possible sources */
> + mux = kzalloc(sizeof(*mux), GFP_KERNEL);
> + if (!mux)
> + return;
> + mux->reg = reg;
> + mux->shift = 24;
> + mux->mask = 0x07;
> + mux->lock = &sun8i_display_lock;
> + }
> +
> + gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> + if (!gate)
> + goto free_gate;
> +
> + gate->reg = reg;
> + gate->bit_idx = 31;
> + gate->lock = &sun8i_display_lock;
> +
> + div = kzalloc(sizeof(*div), GFP_KERNEL);
> + if (!div)
> + goto free_gate;
> +
> + div->reg = reg;
> + div->shift = 0;
> + div->width = 4;
> + div->lock = &sun8i_display_lock;
> +
> + clk = clk_register_composite(NULL, clk_name,
> + parents, n,
> + mux ? &mux->hw : NULL, &clk_mux_ops,
> + &div->hw, &clk_divider_ops,
> + &gate->hw, &clk_gate_ops,
> + 0);
> + if (IS_ERR(clk)) {
> + pr_err("%s: Couldn't register the clock\n", clk_name);
> + goto free_div;
> + }
> +
> + of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +
> + return;
> +
> +free_div:
> + kfree(div);
> +free_gate:
> + kfree(gate);
> + kfree(mux);
> +}
> +
> +CLK_OF_DECLARE(sun8i_display, "allwinner,sun8i-display-clk", sun8i_display_setup);
As part of my DRM patches, I've added a clk-display clock that can
handle that easily.
And actually, as part of bringing up the display engine on the A33, I
already did it:
https://github.com/mripard/linux/commit/92b6843b5ee5b70cb2be3638df31d3eca28a4dba
https://github.com/mripard/linux/commit/81e8ea74be5e72124eb584432bb79ff75f90d9ed
Thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20160118/190d887b/attachment.sig>
More information about the dri-devel
mailing list