diff options
Diffstat (limited to 'drivers/clk/at91/clk-sam9x60-pll.c')
| -rw-r--r-- | drivers/clk/at91/clk-sam9x60-pll.c | 174 |
1 files changed, 145 insertions, 29 deletions
diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c index 34e3ab13741a..d757003004cb 100644 --- a/drivers/clk/at91/clk-sam9x60-pll.c +++ b/drivers/clk/at91/clk-sam9x60-pll.c @@ -5,6 +5,7 @@ */ #include <linux/bitfield.h> +#include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> @@ -38,19 +39,24 @@ struct sam9x60_pll_core { struct sam9x60_frac { struct sam9x60_pll_core core; + struct at91_clk_pms pms; u32 frac; u16 mul; }; struct sam9x60_div { struct sam9x60_pll_core core; + struct at91_clk_pms pms; u8 div; + u8 safe_div; }; #define to_sam9x60_pll_core(hw) container_of(hw, struct sam9x60_pll_core, hw) #define to_sam9x60_frac(core) container_of(core, struct sam9x60_frac, core) #define to_sam9x60_div(core) container_of(core, struct sam9x60_div, core) +static struct sam9x60_div *notifier_div; + static inline bool sam9x60_pll_ready(struct regmap *regmap, int id) { unsigned int status; @@ -71,13 +77,12 @@ static unsigned long sam9x60_frac_pll_recalc_rate(struct clk_hw *hw, struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); struct sam9x60_frac *frac = to_sam9x60_frac(core); - return (parent_rate * (frac->mul + 1) + - ((u64)parent_rate * frac->frac >> 22)); + return parent_rate * (frac->mul + 1) + + DIV_ROUND_CLOSEST_ULL((u64)parent_rate * frac->frac, (1 << 22)); } -static int sam9x60_frac_pll_prepare(struct clk_hw *hw) +static int sam9x60_frac_pll_set(struct sam9x60_pll_core *core) { - struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); struct sam9x60_frac *frac = to_sam9x60_frac(core); struct regmap *regmap = core->regmap; unsigned int val, cfrac, cmul; @@ -141,6 +146,13 @@ unlock: return 0; } +static int sam9x60_frac_pll_prepare(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_frac_pll_set(core); +} + static void sam9x60_frac_pll_unprepare(struct clk_hw *hw) { struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); @@ -280,6 +292,25 @@ unlock: return ret; } +static int sam9x60_frac_pll_save_context(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_frac *frac = to_sam9x60_frac(core); + + frac->pms.status = sam9x60_pll_ready(core->regmap, core->id); + + return 0; +} + +static void sam9x60_frac_pll_restore_context(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_frac *frac = to_sam9x60_frac(core); + + if (frac->pms.status) + sam9x60_frac_pll_set(core); +} + static const struct clk_ops sam9x60_frac_pll_ops = { .prepare = sam9x60_frac_pll_prepare, .unprepare = sam9x60_frac_pll_unprepare, @@ -287,6 +318,8 @@ static const struct clk_ops sam9x60_frac_pll_ops = { .recalc_rate = sam9x60_frac_pll_recalc_rate, .round_rate = sam9x60_frac_pll_round_rate, .set_rate = sam9x60_frac_pll_set_rate, + .save_context = sam9x60_frac_pll_save_context, + .restore_context = sam9x60_frac_pll_restore_context, }; static const struct clk_ops sam9x60_frac_pll_ops_chg = { @@ -296,11 +329,32 @@ static const struct clk_ops sam9x60_frac_pll_ops_chg = { .recalc_rate = sam9x60_frac_pll_recalc_rate, .round_rate = sam9x60_frac_pll_round_rate, .set_rate = sam9x60_frac_pll_set_rate_chg, + .save_context = sam9x60_frac_pll_save_context, + .restore_context = sam9x60_frac_pll_restore_context, }; -static int sam9x60_div_pll_prepare(struct clk_hw *hw) +/* This function should be called with spinlock acquired. */ +static void sam9x60_div_pll_set_div(struct sam9x60_pll_core *core, u32 div, + bool enable) +{ + struct regmap *regmap = core->regmap; + u32 ena_msk = enable ? core->layout->endiv_mask : 0; + u32 ena_val = enable ? (1 << core->layout->endiv_shift) : 0; + + regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, + core->layout->div_mask | ena_msk, + (div << core->layout->div_shift) | ena_val); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK, + AT91_PMC_PLL_UPDT_UPDATE | core->id); + + while (!sam9x60_pll_ready(regmap, core->id)) + cpu_relax(); +} + +static int sam9x60_div_pll_set(struct sam9x60_pll_core *core) { - struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); struct sam9x60_div *div = to_sam9x60_div(core); struct regmap *regmap = core->regmap; unsigned long flags; @@ -316,17 +370,7 @@ static int sam9x60_div_pll_prepare(struct clk_hw *hw) if (!!(val & core->layout->endiv_mask) && cdiv == div->div) goto unlock; - regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, - core->layout->div_mask | core->layout->endiv_mask, - (div->div << core->layout->div_shift) | - (1 << core->layout->endiv_shift)); - - regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, - AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK, - AT91_PMC_PLL_UPDT_UPDATE | core->id); - - while (!sam9x60_pll_ready(regmap, core->id)) - cpu_relax(); + sam9x60_div_pll_set_div(core, div->div, 1); unlock: spin_unlock_irqrestore(core->lock, flags); @@ -334,6 +378,13 @@ unlock: return 0; } +static int sam9x60_div_pll_prepare(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_div_pll_set(core); +} + static void sam9x60_div_pll_unprepare(struct clk_hw *hw) { struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); @@ -465,16 +516,7 @@ static int sam9x60_div_pll_set_rate_chg(struct clk_hw *hw, unsigned long rate, if (cdiv == div->div) goto unlock; - regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, - core->layout->div_mask, - (div->div << core->layout->div_shift)); - - regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, - AT91_PMC_PLL_UPDT_UPDATE | AT91_PMC_PLL_UPDT_ID_MSK, - AT91_PMC_PLL_UPDT_UPDATE | core->id); - - while (!sam9x60_pll_ready(regmap, core->id)) - cpu_relax(); + sam9x60_div_pll_set_div(core, div->div, 0); unlock: spin_unlock_irqrestore(core->lock, irqflags); @@ -482,6 +524,67 @@ unlock: return 0; } +static int sam9x60_div_pll_save_context(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_div *div = to_sam9x60_div(core); + + div->pms.status = sam9x60_div_pll_is_prepared(hw); + + return 0; +} + +static void sam9x60_div_pll_restore_context(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_div *div = to_sam9x60_div(core); + + if (div->pms.status) + sam9x60_div_pll_set(core); +} + +static int sam9x60_div_pll_notifier_fn(struct notifier_block *notifier, + unsigned long code, void *data) +{ + struct sam9x60_div *div = notifier_div; + struct sam9x60_pll_core core = div->core; + struct regmap *regmap = core.regmap; + unsigned long irqflags; + u32 val, cdiv; + int ret = NOTIFY_DONE; + + if (code != PRE_RATE_CHANGE) + return ret; + + /* + * We switch to safe divider to avoid overclocking of other domains + * feed by us while the frac PLL (our parent) is changed. + */ + div->div = div->safe_div; + + spin_lock_irqsave(core.lock, irqflags); + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, AT91_PMC_PLL_UPDT_ID_MSK, + core.id); + regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val); + cdiv = (val & core.layout->div_mask) >> core.layout->div_shift; + + /* Stop if nothing changed. */ + if (cdiv == div->safe_div) + goto unlock; + + sam9x60_div_pll_set_div(&core, div->div, 0); + ret = NOTIFY_OK; + +unlock: + spin_unlock_irqrestore(core.lock, irqflags); + + return ret; +} + +static struct notifier_block sam9x60_div_pll_notifier = { + .notifier_call = sam9x60_div_pll_notifier_fn, +}; + static const struct clk_ops sam9x60_div_pll_ops = { .prepare = sam9x60_div_pll_prepare, .unprepare = sam9x60_div_pll_unprepare, @@ -489,6 +592,8 @@ static const struct clk_ops sam9x60_div_pll_ops = { .recalc_rate = sam9x60_div_pll_recalc_rate, .round_rate = sam9x60_div_pll_round_rate, .set_rate = sam9x60_div_pll_set_rate, + .save_context = sam9x60_div_pll_save_context, + .restore_context = sam9x60_div_pll_restore_context, }; static const struct clk_ops sam9x60_div_pll_ops_chg = { @@ -498,6 +603,8 @@ static const struct clk_ops sam9x60_div_pll_ops_chg = { .recalc_rate = sam9x60_div_pll_recalc_rate, .round_rate = sam9x60_div_pll_round_rate, .set_rate = sam9x60_div_pll_set_rate_chg, + .save_context = sam9x60_div_pll_save_context, + .restore_context = sam9x60_div_pll_restore_context, }; struct clk_hw * __init @@ -587,7 +694,8 @@ struct clk_hw * __init sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock, const char *name, const char *parent_name, u8 id, const struct clk_pll_characteristics *characteristics, - const struct clk_pll_layout *layout, u32 flags) + const struct clk_pll_layout *layout, u32 flags, + u32 safe_div) { struct sam9x60_div *div; struct clk_hw *hw; @@ -596,9 +704,13 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock, unsigned int val; int ret; - if (id > PLL_MAX_ID || !lock) + /* We only support one changeable PLL. */ + if (id > PLL_MAX_ID || !lock || (safe_div && notifier_div)) return ERR_PTR(-EINVAL); + if (safe_div >= PLL_DIV_MAX) + safe_div = PLL_DIV_MAX - 1; + div = kzalloc(sizeof(*div), GFP_KERNEL); if (!div) return ERR_PTR(-ENOMEM); @@ -618,6 +730,7 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock, div->core.layout = layout; div->core.regmap = regmap; div->core.lock = lock; + div->safe_div = safe_div; spin_lock_irqsave(div->core.lock, irqflags); @@ -633,6 +746,9 @@ sam9x60_clk_register_div_pll(struct regmap *regmap, spinlock_t *lock, if (ret) { kfree(div); hw = ERR_PTR(ret); + } else if (div->safe_div) { + notifier_div = div; + clk_notifier_register(hw->clk, &sam9x60_div_pll_notifier); } return hw; |