diff options
| -rw-r--r-- | drivers/clk/Makefile | 3 | ||||
| -rw-r--r-- | drivers/clk/clk-gate-shared.c | 123 | ||||
| -rw-r--r-- | include/linux/clk.h | 3 |
3 files changed, 128 insertions, 1 deletions
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index a4e4ed0241..5811d28b88 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_COMMON_CLK) += clk.o clk-fixed.o clk-divider.o clk-fixed-factor.o \ clk-mux.o clk-gate.o clk-composite.o \ - clk-fractional-divider.o clk-conf.o + clk-fractional-divider.o clk-conf.o \ + clk-gate-shared.o obj-$(CONFIG_CLKDEV_LOOKUP) += clkdev.o obj-$(CONFIG_ARCH_MVEBU) += mvebu/ diff --git a/drivers/clk/clk-gate-shared.c b/drivers/clk/clk-gate-shared.c new file mode 100644 index 0000000000..a95f940dd2 --- /dev/null +++ b/drivers/clk/clk-gate-shared.c @@ -0,0 +1,123 @@ +/* + * clk-gate-shared.c - generic barebox clock support. Based on Linux clk support + * + * Copyright (c) 2017 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix + * + * 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 <common.h> +#include <io.h> +#include <malloc.h> +#include <linux/clk.h> +#include <linux/err.h> + +struct clk_gate_shared { + struct clk clk; + const char *parent; + const char *companion_gate; + struct clk *companion_clk; +}; + +#define to_clk_gate_shared(_clk) container_of(_clk, struct clk_gate_shared, clk) + +static struct clk *lookup_companion(struct clk_gate_shared *g) +{ + if (IS_ERR(g->companion_clk)) + g->companion_clk = clk_lookup(g->companion_gate); + + if (IS_ERR(g->companion_clk)) + return NULL; + + return g->companion_clk; +} + +static int clk_gate_shared_enable(struct clk *clk) +{ + struct clk_gate_shared *g = to_clk_gate_shared(clk); + + return clk_enable(lookup_companion(g)); +} + +static void clk_gate_shared_disable(struct clk *clk) +{ + struct clk_gate_shared *g = to_clk_gate_shared(clk); + + clk_disable(lookup_companion(g)); +} + +static int clk_gate_shared_is_enabled(struct clk *clk) +{ + struct clk_gate_shared *g = to_clk_gate_shared(clk); + + return clk_is_enabled(lookup_companion(g)); +} + +static struct clk_ops clk_gate_shared_ops = { + .set_rate = clk_parent_set_rate, + .round_rate = clk_parent_round_rate, + .enable = clk_gate_shared_enable, + .disable = clk_gate_shared_disable, + .is_enabled = clk_gate_shared_is_enabled, +}; + +struct clk *clk_gate_shared_alloc(const char *name, const char *parent, const char *companion, + unsigned flags) +{ + struct clk_gate_shared *g = xzalloc(sizeof(*g)); + + g->parent = parent; + g->companion_gate = companion; + g->companion_clk = ERR_PTR(-EINVAL); + g->clk.ops = &clk_gate_shared_ops; + g->clk.name = name; + g->clk.flags = flags; + g->clk.parent_names = &g->parent; + g->clk.num_parents = 1; + + return &g->clk; +} + +void clk_gate_shared_free(struct clk *clk) +{ + struct clk_gate_shared *g = to_clk_gate_shared(clk); + + free(g); +} + +/* + * clk_gate_shared - register a gate controlled by another gate + * @name: The name of the new clock gate + * @parent: The parent name of the new clock + * companion: The hardware gate this clock is controlled by + * @flags: common CLK_* flags + * + * This gate clock is used when a single software control knob controls multiple + * gates in hardware. The first gate is then registered as the real hardware gate, + * the others are registered with this function. This gate has no hardware control + * itself, but only enables/disabled its companion hardware gate. + */ +struct clk *clk_gate_shared(const char *name, const char *parent, const char *companion, + unsigned flags) +{ + struct clk *clk; + int ret; + + clk = clk_gate_shared_alloc(name , parent, companion, flags); + + ret = clk_register(clk); + if (ret) { + clk_gate_shared_free(clk); + return ERR_PTR(ret); + } + + return clk; +} diff --git a/include/linux/clk.h b/include/linux/clk.h index 697ab4ff4a..7dd52388c5 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -296,6 +296,9 @@ struct clk *clk_gate(const char *name, const char *parent, void __iomem *reg, u8 shift, unsigned flags, u8 clk_gate_flags); struct clk *clk_gate_inverted(const char *name, const char *parent, void __iomem *reg, u8 shift, unsigned flags); +struct clk *clk_gate_shared(const char *name, const char *parent, const char *shared, + unsigned flags); + int clk_is_enabled(struct clk *clk); int clk_is_enabled_always(struct clk *clk); |