From c6cf4d3248980c5e1998ce21f3c2d86502f7e1a9 Mon Sep 17 00:00:00 2001 From: Gabriel Fernandez Date: Thu, 8 Mar 2018 17:53:58 +0100 Subject: [PATCH] clk: stm32mp1: add PLL clocks STMP32MP1 has 4 PLLs. PLL supports integer and fractional mode. Each PLL has 3 output dividers (p, q, r) Signed-off-by: Gabriel Fernandez Signed-off-by: Michael Turquette --- drivers/clk/clk-stm32mp1.c | 209 +++++++++++++++++++++++++++++++++++++ 1 file changed, 209 insertions(+) diff --git a/drivers/clk/clk-stm32mp1.c b/drivers/clk/clk-stm32mp1.c index 47984f36494b..d62a3a94cc67 100644 --- a/drivers/clk/clk-stm32mp1.c +++ b/drivers/clk/clk-stm32mp1.c @@ -7,6 +7,7 @@ #include #include +#include #include #include #include @@ -321,6 +322,196 @@ clk_stm32_register_gate_ops(struct device *dev, return hw; } +/* STM32 PLL */ + +struct stm32_pll_obj { + /* lock pll enable/disable registers */ + spinlock_t *lock; + void __iomem *reg; + struct clk_hw hw; +}; + +#define to_pll(_hw) container_of(_hw, struct stm32_pll_obj, hw) + +#define PLL_ON BIT(0) +#define PLL_RDY BIT(1) +#define DIVN_MASK 0x1FF +#define DIVM_MASK 0x3F +#define DIVM_SHIFT 16 +#define DIVN_SHIFT 0 +#define FRAC_OFFSET 0xC +#define FRAC_MASK 0x1FFF +#define FRAC_SHIFT 3 +#define FRACLE BIT(16) + +static int __pll_is_enabled(struct clk_hw *hw) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + + return readl_relaxed(clk_elem->reg) & PLL_ON; +} + +#define TIMEOUT 5 + +static int pll_enable(struct clk_hw *hw) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + u32 reg; + unsigned long flags = 0; + unsigned int timeout = TIMEOUT; + int bit_status = 0; + + spin_lock_irqsave(clk_elem->lock, flags); + + if (__pll_is_enabled(hw)) + goto unlock; + + reg = readl_relaxed(clk_elem->reg); + reg |= PLL_ON; + writel_relaxed(reg, clk_elem->reg); + + /* We can't use readl_poll_timeout() because we can be blocked if + * someone enables this clock before clocksource changes. + * Only jiffies counter is available. Jiffies are incremented by + * interruptions and enable op does not allow to be interrupted. + */ + do { + bit_status = !(readl_relaxed(clk_elem->reg) & PLL_RDY); + + if (bit_status) + udelay(120); + + } while (bit_status && --timeout); + +unlock: + spin_unlock_irqrestore(clk_elem->lock, flags); + + return bit_status; +} + +static void pll_disable(struct clk_hw *hw) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + u32 reg; + unsigned long flags = 0; + + spin_lock_irqsave(clk_elem->lock, flags); + + reg = readl_relaxed(clk_elem->reg); + reg &= ~PLL_ON; + writel_relaxed(reg, clk_elem->reg); + + spin_unlock_irqrestore(clk_elem->lock, flags); +} + +static u32 pll_frac_val(struct clk_hw *hw) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + u32 reg, frac = 0; + + reg = readl_relaxed(clk_elem->reg + FRAC_OFFSET); + if (reg & FRACLE) + frac = (reg >> FRAC_SHIFT) & FRAC_MASK; + + return frac; +} + +static unsigned long pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + u32 reg; + u32 frac, divm, divn; + u64 rate, rate_frac = 0; + + reg = readl_relaxed(clk_elem->reg + 4); + + divm = ((reg >> DIVM_SHIFT) & DIVM_MASK) + 1; + divn = ((reg >> DIVN_SHIFT) & DIVN_MASK) + 1; + rate = (u64)parent_rate * divn; + + do_div(rate, divm); + + frac = pll_frac_val(hw); + if (frac) { + rate_frac = (u64)parent_rate * (u64)frac; + do_div(rate_frac, (divm * 8192)); + } + + return rate + rate_frac; +} + +static int pll_is_enabled(struct clk_hw *hw) +{ + struct stm32_pll_obj *clk_elem = to_pll(hw); + unsigned long flags = 0; + int ret; + + spin_lock_irqsave(clk_elem->lock, flags); + ret = __pll_is_enabled(hw); + spin_unlock_irqrestore(clk_elem->lock, flags); + + return ret; +} + +static const struct clk_ops pll_ops = { + .enable = pll_enable, + .disable = pll_disable, + .recalc_rate = pll_recalc_rate, + .is_enabled = pll_is_enabled, +}; + +static struct clk_hw *clk_register_pll(struct device *dev, const char *name, + const char *parent_name, + void __iomem *reg, + unsigned long flags, + spinlock_t *lock) +{ + struct stm32_pll_obj *element; + struct clk_init_data init; + struct clk_hw *hw; + int err; + + element = kzalloc(sizeof(*element), GFP_KERNEL); + if (!element) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &pll_ops; + init.flags = flags; + init.parent_names = &parent_name; + init.num_parents = 1; + + element->hw.init = &init; + element->reg = reg; + element->lock = lock; + + hw = &element->hw; + err = clk_hw_register(dev, hw); + + if (err) { + kfree(element); + return ERR_PTR(err); + } + + return hw; +} + +struct stm32_pll_cfg { + u32 offset; +}; + +struct clk_hw *_clk_register_pll(struct device *dev, + struct clk_hw_onecell_data *clk_data, + void __iomem *base, spinlock_t *lock, + const struct clock_config *cfg) +{ + struct stm32_pll_cfg *stm_pll_cfg = cfg->cfg; + + return clk_register_pll(dev, cfg->name, cfg->parent_name, + base + stm_pll_cfg->offset, cfg->flags, lock); +} + static struct clk_hw * _clk_stm32_register_gate(struct device *dev, struct clk_hw_onecell_data *clk_data, @@ -400,6 +591,18 @@ _clk_stm32_register_gate(struct device *dev, .func = _clk_hw_register_mux,\ } +#define PLL(_id, _name, _parent, _flags, _offset)\ +{\ + .id = _id,\ + .name = _name,\ + .parent_name = _parent,\ + .flags = _flags,\ + .cfg = &(struct stm32_pll_cfg) {\ + .offset = _offset,\ + },\ + .func = _clk_register_pll,\ +} + /* STM32 GATE */ #define STM32_GATE(_id, _name, _parent, _flags, _gate)\ {\ @@ -452,6 +655,12 @@ static const struct clock_config stm32mp1_clock_cfg[] = { MUX(NO_ID, "ref4", ref4_parents, CLK_OPS_PARENT_ENABLE, RCC_RCK4SELR, 0, 2, CLK_MUX_READ_ONLY), + + /* PLLs */ + PLL(PLL1, "pll1", "ref1", CLK_IGNORE_UNUSED, RCC_PLL1CR), + PLL(PLL2, "pll2", "ref1", CLK_IGNORE_UNUSED, RCC_PLL2CR), + PLL(PLL3, "pll3", "ref3", CLK_IGNORE_UNUSED, RCC_PLL3CR), + PLL(PLL4, "pll4", "ref4", CLK_IGNORE_UNUSED, RCC_PLL4CR), }; struct stm32_clock_match_data {