diff options
Diffstat (limited to 'kernel/drivers/clk/samsung/clk.c')
| -rw-r--r-- | kernel/drivers/clk/samsung/clk.c | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/kernel/drivers/clk/samsung/clk.c b/kernel/drivers/clk/samsung/clk.c new file mode 100644 index 000000000..9e1f88c04 --- /dev/null +++ b/kernel/drivers/clk/samsung/clk.c @@ -0,0 +1,420 @@ +/* + * 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/of_address.h> +#include <linux/syscore_ops.h> + +#include "clk.h" + +static LIST_HEAD(clock_reg_cache_list); + +void samsung_clk_save(void __iomem *base, + struct samsung_clk_reg_dump *rd, + unsigned int num_regs) +{ + for (; num_regs > 0; --num_regs, ++rd) + rd->value = readl(base + rd->offset); +} + +void samsung_clk_restore(void __iomem *base, + const struct samsung_clk_reg_dump *rd, + unsigned int num_regs) +{ + for (; num_regs > 0; --num_regs, ++rd) + writel(rd->value, base + rd->offset); +} + +struct samsung_clk_reg_dump *samsung_clk_alloc_reg_dump( + const unsigned long *rdump, + unsigned long nr_rdump) +{ + struct samsung_clk_reg_dump *rd; + unsigned int i; + + rd = kcalloc(nr_rdump, sizeof(*rd), GFP_KERNEL); + if (!rd) + return NULL; + + for (i = 0; i < nr_rdump; ++i) + rd[i].offset = rdump[i]; + + return rd; +} + +/* setup the essentials required to support clock lookup using ccf */ +struct samsung_clk_provider *__init samsung_clk_init(struct device_node *np, + void __iomem *base, unsigned long nr_clks) +{ + struct samsung_clk_provider *ctx; + struct clk **clk_table; + int i; + + ctx = kzalloc(sizeof(struct samsung_clk_provider), GFP_KERNEL); + if (!ctx) + panic("could not allocate clock provider context.\n"); + + clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL); + if (!clk_table) + panic("could not allocate clock lookup table\n"); + + for (i = 0; i < nr_clks; ++i) + clk_table[i] = ERR_PTR(-ENOENT); + + ctx->reg_base = base; + ctx->clk_data.clks = clk_table; + ctx->clk_data.clk_num = nr_clks; + spin_lock_init(&ctx->lock); + + return ctx; +} + +void __init samsung_clk_of_add_provider(struct device_node *np, + struct samsung_clk_provider *ctx) +{ + if (np) { + if (of_clk_add_provider(np, of_clk_src_onecell_get, + &ctx->clk_data)) + panic("could not register clk provider\n"); + } +} + +/* add a clock instance to the clock lookup table used for dt based lookup */ +void samsung_clk_add_lookup(struct samsung_clk_provider *ctx, struct clk *clk, + unsigned int id) +{ + if (ctx->clk_data.clks && id) + ctx->clk_data.clks[id] = clk; +} + +/* register a list of aliases */ +void __init samsung_clk_register_alias(struct samsung_clk_provider *ctx, + struct samsung_clock_alias *list, + unsigned int nr_clk) +{ + struct clk *clk; + unsigned int idx, ret; + + if (!ctx->clk_data.clks) { + 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 = ctx->clk_data.clks[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_clk_provider *ctx, + 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(ctx, 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_clk_provider *ctx, + 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(ctx, clk, list->id); + } +} + +/* register a list of mux clocks */ +void __init samsung_clk_register_mux(struct samsung_clk_provider *ctx, + 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, + ctx->reg_base + list->offset, + list->shift, list->width, list->mux_flags, &ctx->lock); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(ctx, 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_clk_provider *ctx, + 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, + ctx->reg_base + list->offset, + list->shift, list->width, list->div_flags, + list->table, &ctx->lock); + else + clk = clk_register_divider(NULL, list->name, + list->parent_name, list->flags, + ctx->reg_base + list->offset, list->shift, + list->width, list->div_flags, &ctx->lock); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock %s\n", __func__, + list->name); + continue; + } + + samsung_clk_add_lookup(ctx, 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_clk_provider *ctx, + 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, ctx->reg_base + list->offset, + list->bit_idx, list->gate_flags, &ctx->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(ctx, clk, list->id); + } +} + +/* + * obtain the clock speed of all external fixed clock sources from device + * tree and register it + */ +void __init samsung_clk_of_register_fixed_ext(struct samsung_clk_provider *ctx, + struct samsung_fixed_rate_clock *fixed_rate_clk, + unsigned int nr_fixed_rate_clk, + const struct of_device_id *clk_matches) +{ + const struct of_device_id *match; + struct device_node *clk_np; + u32 freq; + + for_each_matching_node_and_match(clk_np, clk_matches, &match) { + if (of_property_read_u32(clk_np, "clock-frequency", &freq)) + continue; + fixed_rate_clk[(unsigned long)match->data].fixed_rate = freq; + } + samsung_clk_register_fixed_rate(ctx, fixed_rate_clk, nr_fixed_rate_clk); +} + +/* utility function to get the rate of a specified clock */ +unsigned long _get_rate(const char *clk_name) +{ + struct clk *clk; + + clk = __clk_lookup(clk_name); + if (!clk) { + pr_err("%s: could not find clock %s\n", __func__, clk_name); + return 0; + } + + return clk_get_rate(clk); +} + +#ifdef CONFIG_PM_SLEEP +static int samsung_clk_suspend(void) +{ + struct samsung_clock_reg_cache *reg_cache; + + list_for_each_entry(reg_cache, &clock_reg_cache_list, node) + samsung_clk_save(reg_cache->reg_base, reg_cache->rdump, + reg_cache->rd_num); + return 0; +} + +static void samsung_clk_resume(void) +{ + struct samsung_clock_reg_cache *reg_cache; + + list_for_each_entry(reg_cache, &clock_reg_cache_list, node) + samsung_clk_restore(reg_cache->reg_base, reg_cache->rdump, + reg_cache->rd_num); +} + +static struct syscore_ops samsung_clk_syscore_ops = { + .suspend = samsung_clk_suspend, + .resume = samsung_clk_resume, +}; + +static void samsung_clk_sleep_init(void __iomem *reg_base, + const unsigned long *rdump, + unsigned long nr_rdump) +{ + struct samsung_clock_reg_cache *reg_cache; + + reg_cache = kzalloc(sizeof(struct samsung_clock_reg_cache), + GFP_KERNEL); + if (!reg_cache) + panic("could not allocate register reg_cache.\n"); + reg_cache->rdump = samsung_clk_alloc_reg_dump(rdump, nr_rdump); + + if (!reg_cache->rdump) + panic("could not allocate register dump storage.\n"); + + if (list_empty(&clock_reg_cache_list)) + register_syscore_ops(&samsung_clk_syscore_ops); + + reg_cache->reg_base = reg_base; + reg_cache->rd_num = nr_rdump; + list_add_tail(®_cache->node, &clock_reg_cache_list); +} + +#else +static void samsung_clk_sleep_init(void __iomem *reg_base, + const unsigned long *rdump, + unsigned long nr_rdump) {} +#endif + +/* + * Common function which registers plls, muxes, dividers and gates + * for each CMU. It also add CMU register list to register cache. + */ +struct samsung_clk_provider * __init samsung_cmu_register_one( + struct device_node *np, + struct samsung_cmu_info *cmu) +{ + void __iomem *reg_base; + struct samsung_clk_provider *ctx; + + reg_base = of_iomap(np, 0); + if (!reg_base) { + panic("%s: failed to map registers\n", __func__); + return NULL; + } + + ctx = samsung_clk_init(np, reg_base, cmu->nr_clk_ids); + if (!ctx) { + panic("%s: unable to alllocate ctx\n", __func__); + return ctx; + } + + if (cmu->pll_clks) + samsung_clk_register_pll(ctx, cmu->pll_clks, cmu->nr_pll_clks, + reg_base); + if (cmu->mux_clks) + samsung_clk_register_mux(ctx, cmu->mux_clks, + cmu->nr_mux_clks); + if (cmu->div_clks) + samsung_clk_register_div(ctx, cmu->div_clks, cmu->nr_div_clks); + if (cmu->gate_clks) + samsung_clk_register_gate(ctx, cmu->gate_clks, + cmu->nr_gate_clks); + if (cmu->fixed_clks) + samsung_clk_register_fixed_rate(ctx, cmu->fixed_clks, + cmu->nr_fixed_clks); + if (cmu->fixed_factor_clks) + samsung_clk_register_fixed_factor(ctx, cmu->fixed_factor_clks, + cmu->nr_fixed_factor_clks); + if (cmu->clk_regs) + samsung_clk_sleep_init(reg_base, cmu->clk_regs, + cmu->nr_clk_regs); + + samsung_clk_of_add_provider(np, ctx); + + return ctx; +} |