e8dd920776
Add a driver to control the output of the sample clock generator found in the axg audio clock controller. The goal of this driver is to coherently control the phase provided to the different element using the sample clock generator. This simplify the usage of the sample clock generator a lot, without comprising the ability of the SoC. Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
69 lines
2.1 KiB
C
69 lines
2.1 KiB
C
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
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/*
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* Copyright (c) 2018 BayLibre, SAS.
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* Author: Jerome Brunet <jbrunet@baylibre.com>
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*/
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#include <linux/clk-provider.h>
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#include "clkc-audio.h"
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/*
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* This is a special clock for the audio controller.
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* The phase of mst_sclk clock output can be controlled independently
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* for the outside world (ph0), the tdmout (ph1) and tdmin (ph2).
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* Controlling these 3 phases as just one makes things simpler and
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* give the same clock view to all the element on the i2s bus.
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* If necessary, we can still control the phase in the tdm block
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* which makes these independent control redundant.
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*/
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static inline struct meson_clk_triphase_data *
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meson_clk_triphase_data(struct clk_regmap *clk)
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{
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return (struct meson_clk_triphase_data *)clk->data;
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}
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static void meson_clk_triphase_sync(struct clk_hw *hw)
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{
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struct clk_regmap *clk = to_clk_regmap(hw);
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struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
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unsigned int val;
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/* Get phase 0 and sync it to phase 1 and 2 */
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val = meson_parm_read(clk->map, &tph->ph0);
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meson_parm_write(clk->map, &tph->ph1, val);
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meson_parm_write(clk->map, &tph->ph2, val);
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}
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static int meson_clk_triphase_get_phase(struct clk_hw *hw)
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{
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struct clk_regmap *clk = to_clk_regmap(hw);
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struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
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unsigned int val;
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/* Phase are in sync, reading phase 0 is enough */
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val = meson_parm_read(clk->map, &tph->ph0);
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return meson_clk_degrees_from_val(val, tph->ph0.width);
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}
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static int meson_clk_triphase_set_phase(struct clk_hw *hw, int degrees)
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{
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struct clk_regmap *clk = to_clk_regmap(hw);
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struct meson_clk_triphase_data *tph = meson_clk_triphase_data(clk);
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unsigned int val;
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val = meson_clk_degrees_to_val(degrees, tph->ph0.width);
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meson_parm_write(clk->map, &tph->ph0, val);
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meson_parm_write(clk->map, &tph->ph1, val);
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meson_parm_write(clk->map, &tph->ph2, val);
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return 0;
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}
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const struct clk_ops meson_clk_triphase_ops = {
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.init = meson_clk_triphase_sync,
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.get_phase = meson_clk_triphase_get_phase,
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.set_phase = meson_clk_triphase_set_phase,
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};
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EXPORT_SYMBOL_GPL(meson_clk_triphase_ops);
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