diff options
Diffstat (limited to 'drivers/clk/at91/clk-master.c')
-rw-r--r-- | drivers/clk/at91/clk-master.c | 463 |
1 files changed, 368 insertions, 95 deletions
diff --git a/drivers/clk/at91/clk-master.c b/drivers/clk/at91/clk-master.c index a80427980bf7..b2d0a7f4f7f9 100644 --- a/drivers/clk/at91/clk-master.c +++ b/drivers/clk/at91/clk-master.c @@ -5,6 +5,7 @@ #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> @@ -17,15 +18,7 @@ #define MASTER_DIV_SHIFT 8 #define MASTER_DIV_MASK 0x7 -#define PMC_MCR 0x30 -#define PMC_MCR_ID_MSK GENMASK(3, 0) -#define PMC_MCR_CMD BIT(7) -#define PMC_MCR_DIV GENMASK(10, 8) -#define PMC_MCR_CSS GENMASK(20, 16) #define PMC_MCR_CSS_SHIFT (16) -#define PMC_MCR_EN BIT(28) - -#define PMC_MCR_ID(x) ((x) & PMC_MCR_ID_MSK) #define MASTER_MAX_ID 4 @@ -37,14 +30,19 @@ struct clk_master { 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; @@ -112,97 +110,244 @@ static unsigned long clk_master_div_recalc_rate(struct clk_hw *hw, 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, }; -static int clk_master_div_set_rate(struct clk_hw *hw, unsigned long rate, - unsigned long parent_rate) +/* This function must be called with lock acquired. */ +static int clk_master_div_set(struct clk_master *master, + unsigned long parent_rate, int div) { - struct clk_master *master = to_clk_master(hw); const struct clk_master_characteristics *characteristics = master->characteristics; - unsigned long flags; - int div, i; - - div = DIV_ROUND_CLOSEST(parent_rate, rate); - if (div > ARRAY_SIZE(characteristics->divisors)) - return -EINVAL; + 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 = 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 (i == ARRAY_SIZE(characteristics->divisors)) - return -EINVAL; + 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; - spin_lock_irqsave(master->lock, flags); - regmap_update_bits(master->regmap, master->layout->offset, - (MASTER_DIV_MASK << MASTER_DIV_SHIFT), - (div << MASTER_DIV_SHIFT)); while (!clk_master_ready(master)) cpu_relax(); - spin_unlock_irqrestore(master->lock, flags); + + master->div = characteristics->divisors[div_index]; return 0; } -static int clk_master_div_determine_rate(struct clk_hw *hw, - struct clk_rate_request *req) +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->characteristics; - struct clk_hw *parent; - unsigned long parent_rate, tmp_rate, best_rate = 0; - int i, best_diff = INT_MIN, tmp_diff; + 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; + } - parent = clk_hw_get_parent(hw); - if (!parent) - return -EINVAL; + 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; + } - parent_rate = clk_hw_get_rate(parent); - if (!parent_rate) - return -EINVAL; + 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; + 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_rate = DIV_ROUND_CLOSEST_ULL(parent_rate, - characteristics->divisors[i]); - tmp_diff = abs(tmp_rate - req->rate); + tmp_diff = characteristics->output.max - new_rate; + if (tmp_diff < 0) + continue; - if (!best_rate || best_diff > tmp_diff) { - best_diff = tmp_diff; - best_rate = tmp_rate; + if (best_diff < 0 || best_diff > tmp_diff) { + new_div = characteristics->divisors[i]; + best_diff = tmp_diff; + } + + if (!tmp_diff) + break; } - if (!best_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; } - req->best_parent_rate = best_rate; - req->best_parent_hw = parent; - req->rate = best_rate; +unlock: + spin_unlock_irqrestore(master_div->lock, flags); - return 0; + return ret; } -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, - .determine_rate = clk_master_div_determine_rate, - .set_rate = clk_master_div_set_rate, +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, @@ -272,7 +417,8 @@ static int clk_master_pres_set_rate(struct clk_hw *hw, unsigned long rate, { struct clk_master *master = to_clk_master(hw); unsigned long flags; - unsigned int pres; + unsigned int pres, mckr, tmp; + int ret; pres = DIV_ROUND_CLOSEST(parent_rate, rate); if (pres > MASTER_PRES_MAX) @@ -280,19 +426,31 @@ static int clk_master_pres_set_rate(struct clk_hw *hw, unsigned long rate, else if (pres == 3) pres = MASTER_PRES_MAX; - else + else if (pres) pres = ffs(pres) - 1; spin_lock_irqsave(master->lock, flags); - regmap_update_bits(master->regmap, master->layout->offset, - (MASTER_PRES_MASK << master->layout->pres_shift), - (pres << master->layout->pres_shift)); + ret = regmap_read(master->regmap, master->layout->offset, &mckr); + if (ret) + goto unlock; + + mckr &= master->layout->mask; + tmp = (mckr >> master->layout->pres_shift) & MASTER_PRES_MASK; + if (pres == tmp) + goto unlock; + + mckr &= ~(MASTER_PRES_MASK << master->layout->pres_shift); + mckr |= (pres << master->layout->pres_shift); + ret = regmap_write(master->regmap, master->layout->offset, mckr); + if (ret) + goto unlock; while (!clk_master_ready(master)) cpu_relax(); +unlock: spin_unlock_irqrestore(master->lock, flags); - return 0; + return ret; } static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw, @@ -308,8 +466,9 @@ static unsigned long clk_master_pres_recalc_rate(struct clk_hw *hw, 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 == 3 && characteristics->have_div3_pres) + if (pres == MASTER_PRES_MAX && characteristics->have_div3_pres) pres = 3; else pres = (1 << pres); @@ -327,14 +486,73 @@ static u8 clk_master_pres_get_parent(struct clk_hw *hw) 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 void clk_master_pres_restore_context_chg(struct clk_hw *hw) +{ + struct clk_master *master = to_clk_master(hw); + + clk_master_pres_set_rate(hw, master->pms.rate, master->pms.parent_rate); +} + 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 const struct clk_ops master_pres_ops_chg = { @@ -344,6 +562,8 @@ static const struct clk_ops master_pres_ops_chg = { .recalc_rate = clk_master_pres_recalc_rate, .get_parent = clk_master_pres_get_parent, .set_rate = clk_master_pres_set_rate, + .save_context = clk_master_pres_save_context, + .restore_context = clk_master_pres_restore_context_chg, }; static struct clk_hw * __init @@ -358,6 +578,8 @@ at91_clk_register_master_internal(struct regmap *regmap, 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 || !lock) @@ -380,6 +602,16 @@ at91_clk_register_master_internal(struct regmap *regmap, master->chg_pid = chg_pid; 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) { @@ -416,19 +648,29 @@ at91_clk_register_master_div(struct regmap *regmap, const char *name, const char *parent_name, const struct clk_master_layout *layout, const struct clk_master_characteristics *characteristics, - spinlock_t *lock, u32 flags) + 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; - return at91_clk_register_master_internal(regmap, name, 1, - &parent_name, layout, - characteristics, ops, - lock, flags, -EINVAL); + hw = at91_clk_register_master_internal(regmap, name, 1, + &parent_name, layout, + characteristics, ops, + lock, flags, -EINVAL); + + 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 @@ -539,30 +781,40 @@ static int clk_sama7g5_master_set_parent(struct clk_hw *hw, u8 index) return 0; } -static int clk_sama7g5_master_enable(struct clk_hw *hw) +static void clk_sama7g5_master_set(struct clk_master *master, + unsigned int status) { - struct clk_master *master = to_clk_master(hw); 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, PMC_MCR, PMC_MCR_ID(master->id)); - regmap_read(master->regmap, PMC_MCR, &val); - regmap_update_bits(master->regmap, PMC_MCR, - PMC_MCR_EN | PMC_MCR_CSS | PMC_MCR_DIV | - PMC_MCR_CMD | PMC_MCR_ID_MSK, - PMC_MCR_EN | (master->parent << PMC_MCR_CSS_SHIFT) | - (master->div << MASTER_DIV_SHIFT) | - PMC_MCR_CMD | PMC_MCR_ID(master->id)); + 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 & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT; + 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; } @@ -574,10 +826,12 @@ static void clk_sama7g5_master_disable(struct clk_hw *hw) spin_lock_irqsave(master->lock, flags); - regmap_write(master->regmap, PMC_MCR, master->id); - regmap_update_bits(master->regmap, PMC_MCR, - PMC_MCR_EN | PMC_MCR_CMD | PMC_MCR_ID_MSK, - PMC_MCR_CMD | PMC_MCR_ID(master->id)); + 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); } @@ -590,12 +844,12 @@ static int clk_sama7g5_master_is_enabled(struct clk_hw *hw) spin_lock_irqsave(master->lock, flags); - regmap_write(master->regmap, PMC_MCR, master->id); - regmap_read(master->regmap, PMC_MCR, &val); + 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 & PMC_MCR_EN); + return !!(val & AT91_PMC_MCR_V2_EN); } static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate, @@ -610,7 +864,7 @@ static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate, if (div == 3) div = MASTER_PRES_MAX; - else + else if (div) div = ffs(div) - 1; spin_lock_irqsave(master->lock, flags); @@ -620,6 +874,23 @@ static int clk_sama7g5_master_set_rate(struct clk_hw *hw, unsigned long rate, 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, @@ -629,6 +900,8 @@ static const struct clk_ops sama7g5_master_ops = { .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 @@ -672,10 +945,10 @@ at91_clk_sama7g5_register_master(struct regmap *regmap, master->mux_table = mux_table; spin_lock_irqsave(master->lock, flags); - regmap_write(master->regmap, PMC_MCR, master->id); - regmap_read(master->regmap, PMC_MCR, &val); - master->parent = (val & PMC_MCR_CSS) >> PMC_MCR_CSS_SHIFT; - master->div = (val & PMC_MCR_DIV) >> MASTER_DIV_SHIFT; + 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; |