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36971566ea
SAMA5D2 and SAMA7G5 have a special power saving mode (backup mode) where most of the SoC's components are powered off (including PMC). Resuming from this mode is done with the help of bootloader. Peripherals are not aware of the power saving mode thus most of them are disabling clocks in proper suspend API and re-enable them in resume API without taking into account the previously setup rate. Moreover some of the peripherals are acting as wakeup sources and are not disabling the clocks in this scenario, when suspending. Since backup mode cuts the power for peripherals, in resume part these clocks needs to be re-configured. The initial PMC suspend/resume code was designed only for SAMA5D2's PMC (as it was the only one supporting backup mode). SAMA7G supports also backup mode and its PMC is different (few new functionalities, different registers offsets, different offsets in registers for each functionalities). To address both SAMA5D2 and SAMA7G5 PMC add .save_context()/.resume_context() support to each clocks driver and call this from PMC driver. Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com> Link: https://lore.kernel.org/r/20211011112719.3951784-2-claudiu.beznea@microchip.com Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
140 lines
2.7 KiB
C
140 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
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*/
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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#include <linux/clk/at91_pmc.h>
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#include <linux/of.h>
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#include <linux/mfd/syscon.h>
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#include <linux/regmap.h>
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#include "pmc.h"
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#define SYSTEM_MAX_ID 31
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#define SYSTEM_MAX_NAME_SZ 32
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#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
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struct clk_system {
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struct clk_hw hw;
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struct regmap *regmap;
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struct at91_clk_pms pms;
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u8 id;
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};
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static inline int is_pck(int id)
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{
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return (id >= 8) && (id <= 15);
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}
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static inline bool clk_system_ready(struct regmap *regmap, int id)
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{
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unsigned int status;
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regmap_read(regmap, AT91_PMC_SR, &status);
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return !!(status & (1 << id));
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}
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static int clk_system_prepare(struct clk_hw *hw)
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{
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struct clk_system *sys = to_clk_system(hw);
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regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id);
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if (!is_pck(sys->id))
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return 0;
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while (!clk_system_ready(sys->regmap, sys->id))
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cpu_relax();
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return 0;
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}
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static void clk_system_unprepare(struct clk_hw *hw)
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{
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struct clk_system *sys = to_clk_system(hw);
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regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id);
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}
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static int clk_system_is_prepared(struct clk_hw *hw)
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{
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struct clk_system *sys = to_clk_system(hw);
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unsigned int status;
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regmap_read(sys->regmap, AT91_PMC_SCSR, &status);
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if (!(status & (1 << sys->id)))
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return 0;
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if (!is_pck(sys->id))
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return 1;
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regmap_read(sys->regmap, AT91_PMC_SR, &status);
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return !!(status & (1 << sys->id));
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}
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static int clk_system_save_context(struct clk_hw *hw)
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{
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struct clk_system *sys = to_clk_system(hw);
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sys->pms.status = clk_system_is_prepared(hw);
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return 0;
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}
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static void clk_system_restore_context(struct clk_hw *hw)
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{
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struct clk_system *sys = to_clk_system(hw);
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if (sys->pms.status)
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clk_system_prepare(&sys->hw);
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}
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static const struct clk_ops system_ops = {
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.prepare = clk_system_prepare,
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.unprepare = clk_system_unprepare,
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.is_prepared = clk_system_is_prepared,
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.save_context = clk_system_save_context,
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.restore_context = clk_system_restore_context,
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};
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struct clk_hw * __init
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at91_clk_register_system(struct regmap *regmap, const char *name,
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const char *parent_name, u8 id)
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{
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struct clk_system *sys;
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struct clk_hw *hw;
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struct clk_init_data init;
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int ret;
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if (!parent_name || id > SYSTEM_MAX_ID)
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return ERR_PTR(-EINVAL);
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sys = kzalloc(sizeof(*sys), GFP_KERNEL);
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if (!sys)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &system_ops;
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init.parent_names = &parent_name;
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init.num_parents = 1;
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init.flags = CLK_SET_RATE_PARENT;
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sys->id = id;
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sys->hw.init = &init;
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sys->regmap = regmap;
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hw = &sys->hw;
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ret = clk_hw_register(NULL, &sys->hw);
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if (ret) {
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kfree(sys);
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hw = ERR_PTR(ret);
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}
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return hw;
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}
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