// 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.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> #include "pmc.h" #define MASTER_PRES_MASK 0x7 #define MASTER_PRES_MAX MASTER_PRES_MASK #define MASTER_DIV_SHIFT 8 #define MASTER_DIV_MASK 0x7 #define PMC_MCR_CSS_SHIFT (16) #define MASTER_MAX_ID 4 #define to_clk_master(hw) container_of(hw, struct clk_master, hw) struct clk_master { struct clk_hw hw; struct regmap *regmap; spinlock_t *lock; const struct clk_master_layout *layout; const struct clk_master_characteristics *characteristics; struct at91_clk_pms pms; u32 *mux_table; u32 mckr; int chg_pid; u8 id; u8 parent; u8 div; u32 safe_div; }; /* MCK div reference to be used by notifier. */ static struct clk_master *master_div; static inline bool clk_master_ready(struct clk_master *master) { unsigned int bit = master->id ? AT91_PMC_MCKXRDY : AT91_PMC_MCKRDY; unsigned int status; regmap_read(master->regmap, AT91_PMC_SR, &status); return !!(status & bit); } static int clk_master_prepare(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; spin_lock_irqsave(master->lock, flags); while (!clk_master_ready(master)) cpu_relax(); spin_unlock_irqrestore(master->lock, flags); return 0; } static int clk_master_is_prepared(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; bool status; spin_lock_irqsave(master->lock, flags); status = clk_master_ready(master); spin_unlock_irqrestore(master->lock, flags); return status; } static unsigned long clk_master_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { u8 div; unsigned long flags, rate = parent_rate; struct clk_master *master = to_clk_master(hw); const struct clk_master_layout *layout = master->layout; const struct clk_master_characteristics *characteristics = master->characteristics; unsigned int mckr; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &mckr); spin_unlock_irqrestore(master->lock, flags); mckr &= layout->mask; div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; rate /= characteristics->divisors[div]; if (rate < characteristics->output.min) pr_warn("master clk div is underclocked"); else if (rate > characteristics->output.max) pr_warn("master clk div is overclocked"); return rate; } static int clk_master_div_save_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); struct clk_hw *parent_hw = clk_hw_get_parent(hw); unsigned long flags; unsigned int mckr, div; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &mckr); spin_unlock_irqrestore(master->lock, flags); mckr &= master->layout->mask; div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; div = master->characteristics->divisors[div]; master->pms.parent_rate = clk_hw_get_rate(parent_hw); master->pms.rate = DIV_ROUND_CLOSEST(master->pms.parent_rate, div); return 0; } static void clk_master_div_restore_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; unsigned int mckr; u8 div; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &mckr); spin_unlock_irqrestore(master->lock, flags); mckr &= master->layout->mask; div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; div = master->characteristics->divisors[div]; if (div != DIV_ROUND_CLOSEST(master->pms.parent_rate, master->pms.rate)) pr_warn("MCKR DIV not configured properly by firmware!\n"); } static const struct clk_ops master_div_ops = { .prepare = clk_master_prepare, .is_prepared = clk_master_is_prepared, .recalc_rate = clk_master_div_recalc_rate, .save_context = clk_master_div_save_context, .restore_context = clk_master_div_restore_context, }; /* This function must be called with lock acquired. */ static int clk_master_div_set(struct clk_master *master, unsigned long parent_rate, int div) { const struct clk_master_characteristics *characteristics = master->characteristics; unsigned long rate = parent_rate; unsigned int max_div = 0, div_index = 0, max_div_index = 0; unsigned int i, mckr, tmp; int ret; for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) { if (!characteristics->divisors[i]) break; if (div == characteristics->divisors[i]) div_index = i; if (max_div < characteristics->divisors[i]) { max_div = characteristics->divisors[i]; max_div_index = i; } } if (div > max_div) div_index = max_div_index; ret = regmap_read(master->regmap, master->layout->offset, &mckr); if (ret) return ret; mckr &= master->layout->mask; tmp = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; if (tmp == div_index) return 0; rate /= characteristics->divisors[div_index]; if (rate < characteristics->output.min) pr_warn("master clk div is underclocked"); else if (rate > characteristics->output.max) pr_warn("master clk div is overclocked"); mckr &= ~(MASTER_DIV_MASK << MASTER_DIV_SHIFT); mckr |= (div_index << MASTER_DIV_SHIFT); ret = regmap_write(master->regmap, master->layout->offset, mckr); if (ret) return ret; while (!clk_master_ready(master)) cpu_relax(); master->div = characteristics->divisors[div_index]; return 0; } static unsigned long clk_master_div_recalc_rate_chg(struct clk_hw *hw, unsigned long parent_rate) { struct clk_master *master = to_clk_master(hw); return DIV_ROUND_CLOSEST_ULL(parent_rate, master->div); } static void clk_master_div_restore_context_chg(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; int ret; spin_lock_irqsave(master->lock, flags); ret = clk_master_div_set(master, master->pms.parent_rate, DIV_ROUND_CLOSEST(master->pms.parent_rate, master->pms.rate)); spin_unlock_irqrestore(master->lock, flags); if (ret) pr_warn("Failed to restore MCK DIV clock\n"); } static const struct clk_ops master_div_ops_chg = { .prepare = clk_master_prepare, .is_prepared = clk_master_is_prepared, .recalc_rate = clk_master_div_recalc_rate_chg, .save_context = clk_master_div_save_context, .restore_context = clk_master_div_restore_context_chg, }; static int clk_master_div_notifier_fn(struct notifier_block *notifier, unsigned long code, void *data) { const struct clk_master_characteristics *characteristics = master_div->characteristics; struct clk_notifier_data *cnd = data; unsigned long flags, new_parent_rate, new_rate; unsigned int mckr, div, new_div = 0; int ret, i; long tmp_diff; long best_diff = -1; spin_lock_irqsave(master_div->lock, flags); switch (code) { case PRE_RATE_CHANGE: /* * We want to avoid any overclocking of MCK DIV domain. To do * this we set a safe divider (the underclocking is not of * interest as we can go as low as 32KHz). The relation * b/w this clock and its parents are as follows: * * FRAC PLL -> DIV PLL -> MCK DIV * * With the proper safe divider we should be good even with FRAC * PLL at its maximum value. */ ret = regmap_read(master_div->regmap, master_div->layout->offset, &mckr); if (ret) { ret = NOTIFY_STOP_MASK; goto unlock; } mckr &= master_div->layout->mask; div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; /* Switch to safe divider. */ clk_master_div_set(master_div, cnd->old_rate * characteristics->divisors[div], master_div->safe_div); break; case POST_RATE_CHANGE: /* * At this point we want to restore MCK DIV domain to its maximum * allowed rate. */ ret = regmap_read(master_div->regmap, master_div->layout->offset, &mckr); if (ret) { ret = NOTIFY_STOP_MASK; goto unlock; } mckr &= master_div->layout->mask; div = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; new_parent_rate = cnd->new_rate * characteristics->divisors[div]; for (i = 0; i < ARRAY_SIZE(characteristics->divisors); i++) { if (!characteristics->divisors[i]) break; new_rate = DIV_ROUND_CLOSEST_ULL(new_parent_rate, characteristics->divisors[i]); tmp_diff = characteristics->output.max - new_rate; if (tmp_diff < 0) continue; if (best_diff < 0 || best_diff > tmp_diff) { new_div = characteristics->divisors[i]; best_diff = tmp_diff; } if (!tmp_diff) break; } if (!new_div) { ret = NOTIFY_STOP_MASK; goto unlock; } /* Update the div to preserve MCK DIV clock rate. */ clk_master_div_set(master_div, new_parent_rate, new_div); ret = NOTIFY_OK; break; default: ret = NOTIFY_DONE; break; } unlock: spin_unlock_irqrestore(master_div->lock, flags); return ret; } static struct notifier_block clk_master_div_notifier = { .notifier_call = clk_master_div_notifier_fn, }; static void clk_sama7g5_master_best_diff(struct clk_rate_request *req, struct clk_hw *parent, unsigned long parent_rate, long *best_rate, long *best_diff, u32 div) { unsigned long tmp_rate, tmp_diff; if (div == MASTER_PRES_MAX) tmp_rate = parent_rate / 3; else tmp_rate = parent_rate >> div; tmp_diff = abs(req->rate - tmp_rate); if (*best_diff < 0 || *best_diff >= tmp_diff) { *best_rate = tmp_rate; *best_diff = tmp_diff; req->best_parent_rate = parent_rate; req->best_parent_hw = parent; } } static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_master *master = to_clk_master(hw); const struct clk_master_characteristics *characteristics = master->characteristics; unsigned long flags; unsigned int val, pres; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &val); spin_unlock_irqrestore(master->lock, flags); val &= master->layout->mask; pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK; if (pres == MASTER_PRES_MAX && characteristics->have_div3_pres) pres = 3; else pres = (1 << pres); return DIV_ROUND_CLOSEST_ULL(parent_rate, pres); } static u8 clk_master_pres_get_parent(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; unsigned int mckr; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &mckr); spin_unlock_irqrestore(master->lock, flags); mckr &= master->layout->mask; return mckr & AT91_PMC_CSS; } static int clk_master_pres_save_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); struct clk_hw *parent_hw = clk_hw_get_parent(hw); unsigned long flags; unsigned int val, pres; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &val); spin_unlock_irqrestore(master->lock, flags); val &= master->layout->mask; pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK; if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres) pres = 3; else pres = (1 << pres); master->pms.parent = val & AT91_PMC_CSS; master->pms.parent_rate = clk_hw_get_rate(parent_hw); master->pms.rate = DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres); return 0; } static void clk_master_pres_restore_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; unsigned int val, pres; spin_lock_irqsave(master->lock, flags); regmap_read(master->regmap, master->layout->offset, &val); spin_unlock_irqrestore(master->lock, flags); val &= master->layout->mask; pres = (val >> master->layout->pres_shift) & MASTER_PRES_MASK; if (pres == MASTER_PRES_MAX && master->characteristics->have_div3_pres) pres = 3; else pres = (1 << pres); if (master->pms.rate != DIV_ROUND_CLOSEST_ULL(master->pms.parent_rate, pres) || (master->pms.parent != (val & AT91_PMC_CSS))) pr_warn("MCKR PRES was not configured properly by firmware!\n"); } static const struct clk_ops master_pres_ops = { .prepare = clk_master_prepare, .is_prepared = clk_master_is_prepared, .recalc_rate = clk_master_pres_recalc_rate, .get_parent = clk_master_pres_get_parent, .save_context = clk_master_pres_save_context, .restore_context = clk_master_pres_restore_context, }; static struct clk_hw * __init at91_clk_register_master_internal(struct regmap *regmap, const char *name, int num_parents, const char **parent_names, struct clk_hw **parent_hws, const struct clk_master_layout *layout, const struct clk_master_characteristics *characteristics, const struct clk_ops *ops, spinlock_t *lock, u32 flags) { struct clk_master *master; struct clk_init_data init = {}; struct clk_hw *hw; unsigned int mckr; unsigned long irqflags; int ret; if (!name || !num_parents || !(parent_names || parent_hws) || !lock) return ERR_PTR(-EINVAL); master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return ERR_PTR(-ENOMEM); init.name = name; init.ops = ops; if (parent_hws) init.parent_hws = (const struct clk_hw **)parent_hws; else init.parent_names = parent_names; init.num_parents = num_parents; init.flags = flags; master->hw.init = &init; master->layout = layout; master->characteristics = characteristics; master->regmap = regmap; master->lock = lock; if (ops == &master_div_ops_chg) { spin_lock_irqsave(master->lock, irqflags); regmap_read(master->regmap, master->layout->offset, &mckr); spin_unlock_irqrestore(master->lock, irqflags); mckr &= layout->mask; mckr = (mckr >> MASTER_DIV_SHIFT) & MASTER_DIV_MASK; master->div = characteristics->divisors[mckr]; } hw = &master->hw; ret = clk_hw_register(NULL, &master->hw); if (ret) { kfree(master); hw = ERR_PTR(ret); } return hw; } struct clk_hw * __init at91_clk_register_master_pres(struct regmap *regmap, const char *name, int num_parents, const char **parent_names, struct clk_hw **parent_hws, const struct clk_master_layout *layout, const struct clk_master_characteristics *characteristics, spinlock_t *lock) { return at91_clk_register_master_internal(regmap, name, num_parents, parent_names, parent_hws, layout, characteristics, &master_pres_ops, lock, CLK_SET_RATE_GATE); } struct clk_hw * __init at91_clk_register_master_div(struct regmap *regmap, const char *name, const char *parent_name, struct clk_hw *parent_hw, const struct clk_master_layout *layout, const struct clk_master_characteristics *characteristics, spinlock_t *lock, u32 flags, u32 safe_div) { const struct clk_ops *ops; struct clk_hw *hw; if (flags & CLK_SET_RATE_GATE) ops = &master_div_ops; else ops = &master_div_ops_chg; hw = at91_clk_register_master_internal(regmap, name, 1, parent_name ? &parent_name : NULL, parent_hw ? &parent_hw : NULL, layout, characteristics, ops, lock, flags); if (!IS_ERR(hw) && safe_div) { master_div = to_clk_master(hw); master_div->safe_div = safe_div; clk_notifier_register(hw->clk, &clk_master_div_notifier); } return hw; } static unsigned long clk_sama7g5_master_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct clk_master *master = to_clk_master(hw); return DIV_ROUND_CLOSEST_ULL(parent_rate, (1 << master->div)); } static int clk_sama7g5_master_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { struct clk_master *master = to_clk_master(hw); struct clk_hw *parent; long best_rate = LONG_MIN, best_diff = LONG_MIN; unsigned long parent_rate; unsigned int div, i; /* First: check the dividers of MCR. */ for (i = 0; i < clk_hw_get_num_parents(hw); i++) { parent = clk_hw_get_parent_by_index(hw, i); if (!parent) continue; parent_rate = clk_hw_get_rate(parent); if (!parent_rate) continue; for (div = 0; div < MASTER_PRES_MAX + 1; div++) { clk_sama7g5_master_best_diff(req, parent, parent_rate, &best_rate, &best_diff, div); if (!best_diff) break; } if (!best_diff) break; } /* Second: try to request rate form changeable parent. */ if (master->chg_pid < 0) goto end; parent = clk_hw_get_parent_by_index(hw, master->chg_pid); if (!parent) goto end; for (div = 0; div < MASTER_PRES_MAX + 1; div++) { struct clk_rate_request req_parent; unsigned long req_rate; if (div == MASTER_PRES_MAX) req_rate = req->rate * 3; else req_rate = req->rate << div; clk_hw_forward_rate_request(hw, req, parent, &req_parent, req_rate); if (__clk_determine_rate(parent, &req_parent)) continue; clk_sama7g5_master_best_diff(req, parent, req_parent.rate, &best_rate, &best_diff, div); if (!best_diff) break; } end: pr_debug("MCK: %s, best_rate = %ld, parent clk: %s @ %ld\n", __func__, best_rate, __clk_get_name((req->best_parent_hw)->clk), req->best_parent_rate); if (best_rate < 0) return -EINVAL; req->rate = best_rate; return 0; } static u8 clk_sama7g5_master_get_parent(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; u8 index; spin_lock_irqsave(master->lock, flags); index = clk_mux_val_to_index(&master->hw, master->mux_table, 0, master->parent); spin_unlock_irqrestore(master->lock, flags); return index; } static int clk_sama7g5_master_set_parent(struct clk_hw *hw, u8 index) { struct clk_master *master = to_clk_master(hw); unsigned long flags; if (index >= clk_hw_get_num_parents(hw)) return -EINVAL; spin_lock_irqsave(master->lock, flags); master->parent = clk_mux_index_to_val(master->mux_table, 0, index); spin_unlock_irqrestore(master->lock, flags); return 0; } static void clk_sama7g5_master_set(struct clk_master *master, unsigned int status) { unsigned long flags; unsigned int val, cparent; unsigned int enable = status ? AT91_PMC_MCR_V2_EN : 0; unsigned int parent = master->parent << PMC_MCR_CSS_SHIFT; unsigned int div = master->div << MASTER_DIV_SHIFT; spin_lock_irqsave(master->lock, flags); regmap_write(master->regmap, AT91_PMC_MCR_V2, AT91_PMC_MCR_V2_ID(master->id)); regmap_read(master->regmap, AT91_PMC_MCR_V2, &val); regmap_update_bits(master->regmap, AT91_PMC_MCR_V2, enable | AT91_PMC_MCR_V2_CSS | AT91_PMC_MCR_V2_DIV | AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID_MSK, enable | parent | div | AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID(master->id)); cparent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT; /* Wait here only if parent is being changed. */ while ((cparent != master->parent) && !clk_master_ready(master)) cpu_relax(); spin_unlock_irqrestore(master->lock, flags); } static int clk_sama7g5_master_enable(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); clk_sama7g5_master_set(master, 1); return 0; } static void clk_sama7g5_master_disable(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; spin_lock_irqsave(master->lock, flags); regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id); regmap_update_bits(master->regmap, AT91_PMC_MCR_V2, AT91_PMC_MCR_V2_EN | AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID_MSK, AT91_PMC_MCR_V2_CMD | AT91_PMC_MCR_V2_ID(master->id)); spin_unlock_irqrestore(master->lock, flags); } static int clk_sama7g5_master_is_enabled(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); unsigned long flags; unsigned int val; spin_lock_irqsave(master->lock, flags); regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id); regmap_read(master->regmap, AT91_PMC_MCR_V2, &val); spin_unlock_irqrestore(master->lock, flags); return !!(val & AT91_PMC_MCR_V2_EN); } static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct clk_master *master = to_clk_master(hw); unsigned long div, flags; div = DIV_ROUND_CLOSEST(parent_rate, rate); if ((div > (1 << (MASTER_PRES_MAX - 1))) || (div & (div - 1))) return -EINVAL; if (div == 3) div = MASTER_PRES_MAX; else if (div) div = ffs(div) - 1; spin_lock_irqsave(master->lock, flags); master->div = div; spin_unlock_irqrestore(master->lock, flags); return 0; } static int clk_sama7g5_master_save_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); master->pms.status = clk_sama7g5_master_is_enabled(hw); return 0; } static void clk_sama7g5_master_restore_context(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); if (master->pms.status) clk_sama7g5_master_set(master, master->pms.status); } static const struct clk_ops sama7g5_master_ops = { .enable = clk_sama7g5_master_enable, .disable = clk_sama7g5_master_disable, .is_enabled = clk_sama7g5_master_is_enabled, .recalc_rate = clk_sama7g5_master_recalc_rate, .determine_rate = clk_sama7g5_master_determine_rate, .set_rate = clk_sama7g5_master_set_rate, .get_parent = clk_sama7g5_master_get_parent, .set_parent = clk_sama7g5_master_set_parent, .save_context = clk_sama7g5_master_save_context, .restore_context = clk_sama7g5_master_restore_context, }; struct clk_hw * __init at91_clk_sama7g5_register_master(struct regmap *regmap, const char *name, int num_parents, const char **parent_names, struct clk_hw **parent_hws, u32 *mux_table, spinlock_t *lock, u8 id, bool critical, int chg_pid) { struct clk_master *master; struct clk_hw *hw; struct clk_init_data init = {}; unsigned long flags; unsigned int val; int ret; if (!name || !num_parents || !(parent_names || parent_hws) || !mux_table || !lock || id > MASTER_MAX_ID) return ERR_PTR(-EINVAL); master = kzalloc(sizeof(*master), GFP_KERNEL); if (!master) return ERR_PTR(-ENOMEM); init.name = name; init.ops = &sama7g5_master_ops; if (parent_hws) init.parent_hws = (const struct clk_hw **)parent_hws; else init.parent_names = parent_names; init.num_parents = num_parents; init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; if (chg_pid >= 0) init.flags |= CLK_SET_RATE_PARENT; if (critical) init.flags |= CLK_IS_CRITICAL; master->hw.init = &init; master->regmap = regmap; master->id = id; master->chg_pid = chg_pid; master->lock = lock; master->mux_table = mux_table; spin_lock_irqsave(master->lock, flags); regmap_write(master->regmap, AT91_PMC_MCR_V2, master->id); regmap_read(master->regmap, AT91_PMC_MCR_V2, &val); master->parent = (val & AT91_PMC_MCR_V2_CSS) >> PMC_MCR_CSS_SHIFT; master->div = (val & AT91_PMC_MCR_V2_DIV) >> MASTER_DIV_SHIFT; spin_unlock_irqrestore(master->lock, flags); hw = &master->hw; ret = clk_hw_register(NULL, &master->hw); if (ret) { kfree(master); hw = ERR_PTR(ret); } return hw; } const struct clk_master_layout at91rm9200_master_layout = { .mask = 0x31F, .pres_shift = 2, .offset = AT91_PMC_MCKR, }; const struct clk_master_layout at91sam9x5_master_layout = { .mask = 0x373, .pres_shift = 4, .offset = AT91_PMC_MCKR, };