[PATCH 6/9] clk: sunxi: mod1 clock support

Maxime Ripard
2014-08-04T19:52:06Z

On Sun, Aug 03, 2014 at 07:11:36PM -0300, Emilio L?pez wrote:
> Hi,
>
> El 03/08/14 a las 09:47, Maxime Ripard escibi?:
> >On Thu, Jul 31, 2014 at 06:28:09PM -0300, Emilio L?pez wrote:
> >>The module 1 type of clocks consist of a gate and a mux and are used on
> >>the audio blocks to mux and gate the PLL2 outputs for AC97, IIS or
> >>SPDIF. This commit adds support for them on the sunxi clock driver.
> >>
> >>Not-signed-off-by: Emilio L?pez <emilio@elopez.com.ar>
> >
> >Why so?
> >
> >It looks quite good.
>
> Because I have not tested this with any actual mod1 clients. Once
> Jon or Marcus report it's ok I'll be happy to s/Not-s/S/; same with
> the DT bindings.

Ok.

>
> >>---
> >>
> >>Changes from RFC:
> >> * Document compatible used
> >>
> >> Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
> >> drivers/clk/sunxi/Makefile | 1 +
> >> drivers/clk/sunxi/clk-a10-mod1.c | 69 +++++++++++++++++++++++
> >> 3 files changed, 71 insertions(+)
> >> create mode 100644 drivers/clk/sunxi/clk-a10-mod1.c
> >>
> >>diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>index d18b89b..b028ee2 100644
> >>--- a/Documentation/devicetree/bindings/clock/sunxi.txt
> >>+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> >>@@ -50,6 +50,7 @@ Required properties:
> >> "allwinner,sun8i-a23-apb2-gates-clk" - for the APB2 gates on A23
> >> "allwinner,sun4i-a10-codec-clk" - for the codec clock on A10
> >> "allwinner,sun4i-a10-mod0-clk" - for the module 0 family of clocks
> >>+ "allwinner,sun4i-a10-mod1-clk" - for the module 1 family of clocks
> >> "allwinner,sun7i-a20-out-clk" - for the external output clocks
> >> "allwinner,sun7i-a20-gmac-clk" - for the GMAC clock module on A20/A31
> >> "allwinner,sun4i-a10-usb-clk" - for usb gates + resets on A10 / A20
> >>diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> >>index a7a96f8..75d113d 100644
> >>--- a/drivers/clk/sunxi/Makefile
> >>+++ b/drivers/clk/sunxi/Makefile
> >>@@ -5,6 +5,7 @@
> >> obj-y += clk-sunxi.o clk-factors.o
> >> obj-y += clk-a10-codec.o
> >> obj-y += clk-a10-hosc.o
> >>+obj-y += clk-a10-mod1.o
> >> obj-y += clk-a10-pll2.o
> >> obj-y += clk-a20-gmac.o
> >>
> >>diff --git a/drivers/clk/sunxi/clk-a10-mod1.c b/drivers/clk/sunxi/clk-a10-mod1.c
> >>new file mode 100644
> >>index 0000000..09afd54
> >>--- /dev/null
> >>+++ b/drivers/clk/sunxi/clk-a10-mod1.c
> >>@@ -0,0 +1,69 @@
> >>+/*
> >>+ * Copyright 2014 Emilio L?pez
> >>+ *
> >>+ * Emilio L?pez <emilio@elopez.com.ar>
> >>+ *
> >>+ * 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/clkdev.h>
> >>+#include <linux/of.h>
> >>+#include <linux/of_address.h>
> >>+
> >>+static DEFINE_SPINLOCK(mod1_lock);
> >>+
> >>+#define SUN4I_MOD1_ENABLE 31
> >>+#define SUN4I_MOD1_MUX 16
> >>+#define SUN4I_MOD1_MUX_WIDTH 2
> >>+#define SUN4I_MOD1_MAX_PARENTS 4
> >>+
> >>+static void __init sun4i_mod1_clk_setup(struct device_node *node)
> >>+{
> >>+ struct clk *clk;
> >>+ struct clk_mux *mux;
> >>+ struct clk_gate *gate;
> >>+ const char *parents[4];
> >>+ const char *clk_name = node->name;
> >>+ void __iomem *reg;
> >>+ int i = 0;
> >>+
> >>+ mux = kzalloc(sizeof(*mux), GFP_KERNEL);
> >>+ gate = kzalloc(sizeof(*gate), GFP_KERNEL);
> >>+ if (!mux || !gate) {
> >>+ kfree(mux);
> >>+ kfree(gate);
> >>+ return;
> >>+ }
> >>+
> >>+ of_property_read_string(node, "clock-output-names", &clk_name);
> >>+ reg = of_iomap(node, 0);
> >>+
> >>+ while (i < SUN4I_MOD1_MAX_PARENTS &&
> >>+ (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
> >>+ i++;
> >>+
> >>+ gate->reg = reg;
> >>+ gate->bit_idx = SUN4I_MOD1_ENABLE;
> >>+ gate->lock = &mod1_lock;
> >>+ mux->reg = reg;
> >>+ mux->shift = SUN4I_MOD1_MUX;
> >>+ mux->mask = BIT(SUN4I_MOD1_MUX_WIDTH) - 1;
> >>+ mux->lock = &mod1_lock;
> >>+
> >>+ clk = clk_register_composite(NULL, clk_name, parents, i,
> >>+ &mux->hw, &clk_mux_ops,
> >>+ NULL, NULL,
> >>+ &gate->hw, &clk_gate_ops, 0);
>
> We'll probably need SET_RATE_PARENT here as well
>
> >>+ if (!IS_ERR(clk))
> >>+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
> >>+}
> >>+CLK_OF_DECLARE(sun4i_mod1, "allwinner,sun4i-a10-mod1-clk", sun4i_mod1_clk_setup);
> >
> >Why are you not using clk-sunxi for this? It has pretty much
> >everything in place to do so already.
>
> If this were to have a rate component we could reuse the factors
> infrastructure, but it doesn't, as it's just a gate and a mux.

Ah, yes, we have nothing that combines mux and gate. My bad :)

Maxime

--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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