diff options
Diffstat (limited to 'drivers/clk/at91/clk-master.c')
-rw-r--r-- | drivers/clk/at91/clk-master.c | 310 |
1 files changed, 305 insertions, 5 deletions
diff --git a/drivers/clk/at91/clk-master.c b/drivers/clk/at91/clk-master.c index 88d545b1698c..bd0d8a69a2cf 100644 --- a/drivers/clk/at91/clk-master.c +++ b/drivers/clk/at91/clk-master.c @@ -17,30 +17,49 @@ #define MASTER_DIV_SHIFT 8 #define MASTER_DIV_MASK 0x3 +#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 + #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; + u32 *mux_table; u32 mckr; + int chg_pid; + u8 id; + u8 parent; + u8 div; }; -static inline bool clk_master_ready(struct regmap *regmap) +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(regmap, AT91_PMC_SR, &status); + regmap_read(master->regmap, AT91_PMC_SR, &status); - return !!(status & AT91_PMC_MCKRDY); + return !!(status & bit); } static int clk_master_prepare(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); - while (!clk_master_ready(master->regmap)) + while (!clk_master_ready(master)) cpu_relax(); return 0; @@ -50,7 +69,7 @@ static int clk_master_is_prepared(struct clk_hw *hw) { struct clk_master *master = to_clk_master(hw); - return clk_master_ready(master->regmap); + return clk_master_ready(master); } static unsigned long clk_master_recalc_rate(struct clk_hw *hw, @@ -143,6 +162,287 @@ at91_clk_register_master(struct regmap *regmap, 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 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 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_rate_request req_parent = *req; + 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++) { + if (div == MASTER_PRES_MAX) + req_parent.rate = req->rate * 3; + else + req_parent.rate = req->rate << div; + + 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 int clk_sama7g5_master_enable(struct clk_hw *hw) +{ + struct clk_master *master = to_clk_master(hw); + unsigned long flags; + unsigned int val, cparent; + + 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)); + + cparent = (val & PMC_MCR_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); + + 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, 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)); + + 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, PMC_MCR, master->id); + regmap_read(master->regmap, PMC_MCR, &val); + + spin_unlock_irqrestore(master->lock, flags); + + return !!(val & PMC_MCR_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 + div = ffs(div) - 1; + + spin_lock_irqsave(master->lock, flags); + master->div = div; + spin_unlock_irqrestore(master->lock, flags); + + return 0; +} + +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, +}; + +struct clk_hw * __init +at91_clk_sama7g5_register_master(struct regmap *regmap, + const char *name, int num_parents, + const char **parent_names, + 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 || !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; + 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, 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; + 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, |