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Commit c6cf4d32 authored by Gabriel Fernandez's avatar Gabriel Fernandez Committed by Michael Turquette
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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: default avatarGabriel Fernandez <gabriel.fernandez@st.com>
Signed-off-by: default avatarMichael Turquette <mturquette@baylibre.com>
parent dc32eaac
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+209 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
@@ -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 {