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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/clk/at91/clk-system.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/clk/at91/clk-system.c')
-rw-r--r-- | drivers/clk/at91/clk-system.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-system.c b/drivers/clk/at91/clk-system.c new file mode 100644 index 000000000..80720fd1a --- /dev/null +++ b/drivers/clk/at91/clk-system.c @@ -0,0 +1,140 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> + +#include "pmc.h" + +#define SYSTEM_MAX_ID 31 + +#define SYSTEM_MAX_NAME_SZ 32 + +#define to_clk_system(hw) container_of(hw, struct clk_system, hw) +struct clk_system { + struct clk_hw hw; + struct regmap *regmap; + struct at91_clk_pms pms; + u8 id; +}; + +static inline int is_pck(int id) +{ + return (id >= 8) && (id <= 15); +} + +static inline bool clk_system_ready(struct regmap *regmap, int id) +{ + unsigned int status; + + regmap_read(regmap, AT91_PMC_SR, &status); + + return !!(status & (1 << id)); +} + +static int clk_system_prepare(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + + regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id); + + if (!is_pck(sys->id)) + return 0; + + while (!clk_system_ready(sys->regmap, sys->id)) + cpu_relax(); + + return 0; +} + +static void clk_system_unprepare(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + + regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id); +} + +static int clk_system_is_prepared(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + unsigned int status; + + regmap_read(sys->regmap, AT91_PMC_SCSR, &status); + + if (!(status & (1 << sys->id))) + return 0; + + if (!is_pck(sys->id)) + return 1; + + regmap_read(sys->regmap, AT91_PMC_SR, &status); + + return !!(status & (1 << sys->id)); +} + +static int clk_system_save_context(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + + sys->pms.status = clk_system_is_prepared(hw); + + return 0; +} + +static void clk_system_restore_context(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + + if (sys->pms.status) + clk_system_prepare(&sys->hw); +} + +static const struct clk_ops system_ops = { + .prepare = clk_system_prepare, + .unprepare = clk_system_unprepare, + .is_prepared = clk_system_is_prepared, + .save_context = clk_system_save_context, + .restore_context = clk_system_restore_context, +}; + +struct clk_hw * __init +at91_clk_register_system(struct regmap *regmap, const char *name, + const char *parent_name, u8 id) +{ + struct clk_system *sys; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + if (!parent_name || id > SYSTEM_MAX_ID) + return ERR_PTR(-EINVAL); + + sys = kzalloc(sizeof(*sys), GFP_KERNEL); + if (!sys) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &system_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = CLK_SET_RATE_PARENT; + + sys->id = id; + sys->hw.init = &init; + sys->regmap = regmap; + + hw = &sys->hw; + ret = clk_hw_register(NULL, &sys->hw); + if (ret) { + kfree(sys); + hw = ERR_PTR(ret); + } + + return hw; +} |