diff options
Diffstat (limited to 'drivers/clk/samsung/clk.c')
| -rw-r--r-- | drivers/clk/samsung/clk.c | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/drivers/clk/samsung/clk.c b/drivers/clk/samsung/clk.c new file mode 100644 index 00000000000..cd3c40ab50f --- /dev/null +++ b/drivers/clk/samsung/clk.c @@ -0,0 +1,320 @@ +/* + * Copyright (c) 2013 Samsung Electronics Co., Ltd. + * Copyright (c) 2013 Linaro Ltd. + * Author: Thomas Abraham <thomas.ab@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This file includes utility functions to register clocks to common + * clock framework for Samsung platforms. +*/ + +#include <linux/syscore_ops.h> +#include "clk.h" + +static DEFINE_SPINLOCK(lock); +static struct clk **clk_table; +static void __iomem *reg_base; +#ifdef CONFIG_OF +static struct clk_onecell_data clk_data; +#endif + +#ifdef CONFIG_PM_SLEEP +static struct samsung_clk_reg_dump *reg_dump; +static unsigned long nr_reg_dump; + +static int samsung_clk_suspend(void) +{ + struct samsung_clk_reg_dump *rd = reg_dump; + unsigned long i; + + for (i = 0; i < nr_reg_dump; i++, rd++) + rd->value = __raw_readl(reg_base + rd->offset); + + return 0; +} + +static void samsung_clk_resume(void) +{ + struct samsung_clk_reg_dump *rd = reg_dump; + unsigned long i; + + for (i = 0; i < nr_reg_dump; i++, rd++) + __raw_writel(rd->value, reg_base + rd->offset); +} + +static struct syscore_ops samsung_clk_syscore_ops = { + .suspend = samsung_clk_suspend, + .resume = samsung_clk_resume, +}; +#endif /* CONFIG_PM_SLEEP */ + +/* setup the essentials required to support clock lookup using ccf */ +void __init samsung_clk_init(struct device_node *np, void __iomem *base, + unsigned long nr_clks, unsigned long *rdump, + unsigned long nr_rdump, unsigned long *soc_rdump, + unsigned long nr_soc_rdump) +{ + reg_base = base; + +#ifdef CONFIG_PM_SLEEP + if (rdump && nr_rdump) { + unsigned int idx; + reg_dump = kzalloc(sizeof(struct samsung_clk_reg_dump) + * (nr_rdump + nr_soc_rdump), GFP_KERNEL); + if (!reg_dump) { + pr_err("%s: memory alloc for register dump failed\n", + __func__); + return; + } + + for (idx = 0; idx < nr_rdump; idx++) + reg_dump[idx].offset = rdump[idx]; + for (idx = 0; idx < nr_soc_rdump; idx++) + reg_dump[nr_rdump + idx].offset = soc_rdump[idx]; + nr_reg_dump = nr_rdump + nr_soc_rdump; + register_syscore_ops(&samsung_clk_syscore_ops); + } +#endif + + clk_table = kzalloc(sizeof(struct clk *) * nr_clks, GFP_KERNEL); + if (!clk_table) + panic("could not allocate clock lookup table\n"); + + if (!np) + return; + +#ifdef CONFIG_OF + clk_data.clks = clk_table; + clk_data.clk_num = nr_clks; + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); +#endif +} + +/* add a clock instance to the clock lookup table used for dt based lookup */ +void samsung_clk_add_lookup(struct clk *clk, unsigned int id) +{ + if (clk_table && id) + clk_table[id] = clk; +} + +/* register a list of aliases */ +void __init samsung_clk_register_alias(struct samsung_clock_alias *list, + unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + if (!clk_table) { + pr_err("%s: clock table missing\n", __func__); + return; + } + + for (idx = 0; idx < nr_clk; idx++, list++) { + if (!list->id) { + pr_err("%s: clock id missing for index %d\n", __func__, + idx); + continue; + } + + clk = clk_table[list->id]; + if (!clk) { + pr_err("%s: failed to find clock %d\n", __func__, + list->id); + continue; + } + + ret = clk_register_clkdev(clk, list->alias, list->dev_name); + if (ret) + pr_err("%s: failed to register lookup %s\n", + __func__, list->alias); + } +} + +/* register a list of fixed clocks */ +void __init samsung_clk_register_fixed_rate( + struct samsung_fixed_rate_clock *list, unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + for (idx = 0; idx < nr_clk; idx++, list++) { + clk = clk_register_fixed_rate(NULL, list->name, + list->parent_name, list->flags, list->fixed_rate); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(clk, list->id); + + /* + * Unconditionally add a clock lookup for the fixed rate clocks. + * There are not many of these on any of Samsung platforms. + */ + ret = clk_register_clkdev(clk, list->name, NULL); + if (ret) + pr_err("%s: failed to register clock lookup for %s", + __func__, list->name); + } +} + +/* register a list of fixed factor clocks */ +void __init samsung_clk_register_fixed_factor( + struct samsung_fixed_factor_clock *list, unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx; + + for (idx = 0; idx < nr_clk; idx++, list++) { + clk = clk_register_fixed_factor(NULL, list->name, + list->parent_name, list->flags, list->mult, list->div); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(clk, list->id); + } +} + +/* register a list of mux clocks */ +void __init samsung_clk_register_mux(struct samsung_mux_clock *list, + unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + for (idx = 0; idx < nr_clk; idx++, list++) { + clk = clk_register_mux(NULL, list->name, list->parent_names, + list->num_parents, list->flags, reg_base + list->offset, + list->shift, list->width, list->mux_flags, &lock); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(clk, list->id); + + /* register a clock lookup only if a clock alias is specified */ + if (list->alias) { + ret = clk_register_clkdev(clk, list->alias, + list->dev_name); + if (ret) + pr_err("%s: failed to register lookup %s\n", + __func__, list->alias); + } + } +} + +/* register a list of div clocks */ +void __init samsung_clk_register_div(struct samsung_div_clock *list, + unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + for (idx = 0; idx < nr_clk; idx++, list++) { + if (list->table) + clk = clk_register_divider_table(NULL, list->name, + list->parent_name, list->flags, + reg_base + list->offset, list->shift, + list->width, list->div_flags, + list->table, &lock); + else + clk = clk_register_divider(NULL, list->name, + list->parent_name, list->flags, + reg_base + list->offset, list->shift, + list->width, list->div_flags, &lock); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(clk, list->id); + + /* register a clock lookup only if a clock alias is specified */ + if (list->alias) { + ret = clk_register_clkdev(clk, list->alias, + list->dev_name); + if (ret) + pr_err("%s: failed to register lookup %s\n", + __func__, list->alias); + } + } +} + +/* register a list of gate clocks */ +void __init samsung_clk_register_gate(struct samsung_gate_clock *list, + unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + for (idx = 0; idx < nr_clk; idx++, list++) { + clk = clk_register_gate(NULL, list->name, list->parent_name, + list->flags, reg_base + list->offset, + list->bit_idx, list->gate_flags, &lock); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + /* register a clock lookup only if a clock alias is specified */ + if (list->alias) { + ret = clk_register_clkdev(clk, list->alias, + list->dev_name); + if (ret) + pr_err("%s: failed to register lookup %s\n", + __func__, list->alias); + } + + samsung_clk_add_lookup(clk, list->id); + } +} + +/* + * obtain the clock speed of all external fixed clock sources from device + * tree and register it + */ +#ifdef CONFIG_OF +void __init samsung_clk_of_register_fixed_ext( + struct samsung_fixed_rate_clock *fixed_rate_clk, + unsigned int nr_fixed_rate_clk, + struct of_device_id *clk_matches) +{ + const struct of_device_id *match; + struct device_node *np; + u32 freq; + + for_each_matching_node_and_match(np, clk_matches, &match) { + if (of_property_read_u32(np, "clock-frequency", &freq)) + continue; + fixed_rate_clk[(u32)match->data].fixed_rate = freq; + } + samsung_clk_register_fixed_rate(fixed_rate_clk, nr_fixed_rate_clk); +} +#endif + +/* utility function to get the rate of a specified clock */ +unsigned long _get_rate(const char *clk_name) +{ + struct clk *clk; + unsigned long rate; + + clk = clk_get(NULL, clk_name); + if (IS_ERR(clk)) { + pr_err("%s: could not find clock %s\n", __func__, clk_name); + return 0; + } + rate = clk_get_rate(clk); + clk_put(clk); + return rate; +} |