diff options
Diffstat (limited to 'drivers/clk/at91/clk-sam9x60-pll.c')
| -rw-r--r-- | drivers/clk/at91/clk-sam9x60-pll.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c new file mode 100644 index 000000000..5fe50ba17 --- /dev/null +++ b/drivers/clk/at91/clk-sam9x60-pll.c @@ -0,0 +1,531 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microchip Technology Inc. + * + */ + +#include <linux/bitfield.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> + +#include "pmc.h" + +#define PMC_PLL_CTRL0_DIV_MSK GENMASK(7, 0) +#define PMC_PLL_CTRL1_MUL_MSK GENMASK(31, 24) +#define PMC_PLL_CTRL1_FRACR_MSK GENMASK(21, 0) + +#define PLL_DIV_MAX (FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, UINT_MAX) + 1) +#define UPLL_DIV 2 +#define PLL_MUL_MAX (FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, UINT_MAX) + 1) + +#define FCORE_MIN (600000000) +#define FCORE_MAX (1200000000) + +#define PLL_MAX_ID 7 + +struct sam9x60_pll_core { + struct regmap *regmap; + spinlock_t *lock; + const struct clk_pll_characteristics *characteristics; + const struct clk_pll_layout *layout; + struct clk_hw hw; + u8 id; +}; + +struct sam9x60_frac { + struct sam9x60_pll_core core; + u32 frac; + u16 mul; +}; + +struct sam9x60_div { + struct sam9x60_pll_core core; + u8 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 inline bool sam9x60_pll_ready(struct regmap *regmap, int id) +{ + unsigned int status; + + regmap_read(regmap, AT91_PMC_PLL_ISR0, &status); + + return !!(status & BIT(id)); +} + +static bool sam9x60_frac_pll_ready(struct regmap *regmap, u8 id) +{ + return sam9x60_pll_ready(regmap, id); +} + +static unsigned long sam9x60_frac_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_frac *frac = to_sam9x60_frac(core); + + 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) +{ + 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; + unsigned long flags; + + spin_lock_irqsave(core->lock, flags); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, core->id); + regmap_read(regmap, AT91_PMC_PLL_CTRL1, &val); + cmul = (val & core->layout->mul_mask) >> core->layout->mul_shift; + cfrac = (val & core->layout->frac_mask) >> core->layout->frac_shift; + + if (sam9x60_frac_pll_ready(regmap, core->id) && + (cmul == frac->mul && cfrac == frac->frac)) + goto unlock; + + /* Recommended value for PMC_PLL_ACR */ + if (core->characteristics->upll) + val = AT91_PMC_PLL_ACR_DEFAULT_UPLL; + else + val = AT91_PMC_PLL_ACR_DEFAULT_PLLA; + regmap_write(regmap, AT91_PMC_PLL_ACR, val); + + regmap_write(regmap, AT91_PMC_PLL_CTRL1, + (frac->mul << core->layout->mul_shift) | + (frac->frac << core->layout->frac_shift)); + + if (core->characteristics->upll) { + /* Enable the UTMI internal bandgap */ + val |= AT91_PMC_PLL_ACR_UTMIBG; + regmap_write(regmap, AT91_PMC_PLL_ACR, val); + + udelay(10); + + /* Enable the UTMI internal regulator */ + val |= AT91_PMC_PLL_ACR_UTMIVR; + regmap_write(regmap, AT91_PMC_PLL_ACR, val); + + udelay(10); + } + + 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); + + regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, + AT91_PMC_PLL_CTRL0_ENLOCK | AT91_PMC_PLL_CTRL0_ENPLL, + AT91_PMC_PLL_CTRL0_ENLOCK | AT91_PMC_PLL_CTRL0_ENPLL); + + 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(); + +unlock: + spin_unlock_irqrestore(core->lock, flags); + + return 0; +} + +static void sam9x60_frac_pll_unprepare(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct regmap *regmap = core->regmap; + unsigned long flags; + + spin_lock_irqsave(core->lock, flags); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, core->id); + + regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, AT91_PMC_PLL_CTRL0_ENPLL, 0); + + if (core->characteristics->upll) + regmap_update_bits(regmap, AT91_PMC_PLL_ACR, + AT91_PMC_PLL_ACR_UTMIBG | AT91_PMC_PLL_ACR_UTMIVR, 0); + + 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); + + spin_unlock_irqrestore(core->lock, flags); +} + +static int sam9x60_frac_pll_is_prepared(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_pll_ready(core->regmap, core->id); +} + +static long sam9x60_frac_pll_compute_mul_frac(struct sam9x60_pll_core *core, + unsigned long rate, + unsigned long parent_rate, + bool update) +{ + struct sam9x60_frac *frac = to_sam9x60_frac(core); + unsigned long tmprate, remainder; + unsigned long nmul = 0; + unsigned long nfrac = 0; + + if (rate < FCORE_MIN || rate > FCORE_MAX) + return -ERANGE; + + /* + * Calculate the multiplier associated with the current + * divider that provide the closest rate to the requested one. + */ + nmul = mult_frac(rate, 1, parent_rate); + tmprate = mult_frac(parent_rate, nmul, 1); + remainder = rate - tmprate; + + if (remainder) { + nfrac = DIV_ROUND_CLOSEST_ULL((u64)remainder * (1 << 22), + parent_rate); + + tmprate += DIV_ROUND_CLOSEST_ULL((u64)nfrac * parent_rate, + (1 << 22)); + } + + /* Check if resulted rate is a valid. */ + if (tmprate < FCORE_MIN || tmprate > FCORE_MAX) + return -ERANGE; + + if (update) { + frac->mul = nmul - 1; + frac->frac = nfrac; + } + + return tmprate; +} + +static long sam9x60_frac_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_frac_pll_compute_mul_frac(core, rate, *parent_rate, false); +} + +static int sam9x60_frac_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_frac_pll_compute_mul_frac(core, rate, parent_rate, true); +} + +static const struct clk_ops sam9x60_frac_pll_ops = { + .prepare = sam9x60_frac_pll_prepare, + .unprepare = sam9x60_frac_pll_unprepare, + .is_prepared = sam9x60_frac_pll_is_prepared, + .recalc_rate = sam9x60_frac_pll_recalc_rate, + .round_rate = sam9x60_frac_pll_round_rate, + .set_rate = sam9x60_frac_pll_set_rate, +}; + +static int sam9x60_div_pll_prepare(struct clk_hw *hw) +{ + 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; + unsigned int val, cdiv; + + spin_lock_irqsave(core->lock, flags); + 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 enabled an nothing changed. */ + 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(); + +unlock: + spin_unlock_irqrestore(core->lock, flags); + + return 0; +} + +static void sam9x60_div_pll_unprepare(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct regmap *regmap = core->regmap; + unsigned long flags; + + spin_lock_irqsave(core->lock, flags); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, core->id); + + regmap_update_bits(regmap, AT91_PMC_PLL_CTRL0, + core->layout->endiv_mask, 0); + + 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); + + spin_unlock_irqrestore(core->lock, flags); +} + +static int sam9x60_div_pll_is_prepared(struct clk_hw *hw) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct regmap *regmap = core->regmap; + unsigned long flags; + unsigned int val; + + spin_lock_irqsave(core->lock, flags); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, core->id); + regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val); + + spin_unlock_irqrestore(core->lock, flags); + + return !!(val & core->layout->endiv_mask); +} + +static unsigned long sam9x60_div_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_div *div = to_sam9x60_div(core); + + return DIV_ROUND_CLOSEST_ULL(parent_rate, (div->div + 1)); +} + +static long sam9x60_div_pll_compute_div(struct sam9x60_pll_core *core, + unsigned long *parent_rate, + unsigned long rate) +{ + const struct clk_pll_characteristics *characteristics = + core->characteristics; + struct clk_hw *parent = clk_hw_get_parent(&core->hw); + unsigned long tmp_rate, tmp_parent_rate, tmp_diff; + long best_diff = -1, best_rate = -EINVAL; + u32 divid; + + if (!rate) + return 0; + + if (rate < characteristics->output[0].min || + rate > characteristics->output[0].max) + return -ERANGE; + + for (divid = 1; divid < core->layout->div_mask; divid++) { + tmp_parent_rate = clk_hw_round_rate(parent, rate * divid); + if (!tmp_parent_rate) + continue; + + tmp_rate = DIV_ROUND_CLOSEST_ULL(tmp_parent_rate, divid); + tmp_diff = abs(rate - tmp_rate); + + if (best_diff < 0 || best_diff > tmp_diff) { + *parent_rate = tmp_parent_rate; + best_rate = tmp_rate; + best_diff = tmp_diff; + } + + if (!best_diff) + break; + } + + if (best_rate < characteristics->output[0].min || + best_rate > characteristics->output[0].max) + return -ERANGE; + + return best_rate; +} + +static long sam9x60_div_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + + return sam9x60_div_pll_compute_div(core, parent_rate, rate); +} + +static int sam9x60_div_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sam9x60_pll_core *core = to_sam9x60_pll_core(hw); + struct sam9x60_div *div = to_sam9x60_div(core); + + div->div = DIV_ROUND_CLOSEST(parent_rate, rate) - 1; + + return 0; +} + +static const struct clk_ops sam9x60_div_pll_ops = { + .prepare = sam9x60_div_pll_prepare, + .unprepare = sam9x60_div_pll_unprepare, + .is_prepared = sam9x60_div_pll_is_prepared, + .recalc_rate = sam9x60_div_pll_recalc_rate, + .round_rate = sam9x60_div_pll_round_rate, + .set_rate = sam9x60_div_pll_set_rate, +}; + +struct clk_hw * __init +sam9x60_clk_register_frac_pll(struct regmap *regmap, spinlock_t *lock, + const char *name, const char *parent_name, + struct clk_hw *parent_hw, u8 id, + const struct clk_pll_characteristics *characteristics, + const struct clk_pll_layout *layout, bool critical) +{ + struct sam9x60_frac *frac; + struct clk_hw *hw; + struct clk_init_data init; + unsigned long parent_rate, flags; + unsigned int val; + int ret; + + if (id > PLL_MAX_ID || !lock || !parent_hw) + return ERR_PTR(-EINVAL); + + frac = kzalloc(sizeof(*frac), GFP_KERNEL); + if (!frac) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.parent_names = &parent_name; + init.num_parents = 1; + init.ops = &sam9x60_frac_pll_ops; + init.flags = CLK_SET_RATE_GATE; + if (critical) + init.flags |= CLK_IS_CRITICAL; + + frac->core.id = id; + frac->core.hw.init = &init; + frac->core.characteristics = characteristics; + frac->core.layout = layout; + frac->core.regmap = regmap; + frac->core.lock = lock; + + spin_lock_irqsave(frac->core.lock, flags); + if (sam9x60_pll_ready(regmap, id)) { + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, id); + regmap_read(regmap, AT91_PMC_PLL_CTRL1, &val); + frac->mul = FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, val); + frac->frac = FIELD_GET(PMC_PLL_CTRL1_FRACR_MSK, val); + } else { + /* + * This means the PLL is not setup by bootloaders. In this + * case we need to set the minimum rate for it. Otherwise + * a clock child of this PLL may be enabled before setting + * its rate leading to enabling this PLL with unsupported + * rate. This will lead to PLL not being locked at all. + */ + parent_rate = clk_hw_get_rate(parent_hw); + if (!parent_rate) { + hw = ERR_PTR(-EINVAL); + goto free; + } + + ret = sam9x60_frac_pll_compute_mul_frac(&frac->core, FCORE_MIN, + parent_rate, true); + if (ret < 0) { + hw = ERR_PTR(ret); + goto free; + } + } + spin_unlock_irqrestore(frac->core.lock, flags); + + hw = &frac->core.hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(frac); + hw = ERR_PTR(ret); + } + + return hw; + +free: + spin_unlock_irqrestore(frac->core.lock, flags); + kfree(frac); + return hw; +} + +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, bool critical) +{ + struct sam9x60_div *div; + struct clk_hw *hw; + struct clk_init_data init; + unsigned long flags; + unsigned int val; + int ret; + + if (id > PLL_MAX_ID || !lock) + return ERR_PTR(-EINVAL); + + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.parent_names = &parent_name; + init.num_parents = 1; + init.ops = &sam9x60_div_pll_ops; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE | + CLK_SET_RATE_PARENT; + if (critical) + init.flags |= CLK_IS_CRITICAL; + + div->core.id = id; + div->core.hw.init = &init; + div->core.characteristics = characteristics; + div->core.layout = layout; + div->core.regmap = regmap; + div->core.lock = lock; + + spin_lock_irqsave(div->core.lock, flags); + + regmap_update_bits(regmap, AT91_PMC_PLL_UPDT, + AT91_PMC_PLL_UPDT_ID_MSK, id); + regmap_read(regmap, AT91_PMC_PLL_CTRL0, &val); + div->div = FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, val); + + spin_unlock_irqrestore(div->core.lock, flags); + + hw = &div->core.hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(div); + hw = ERR_PTR(ret); + } + + return hw; +} + |