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Subject[PATCH v2 05/12] clk: stm32mp1: add PLL clocks
Date
From: Gabriel Fernandez <gabriel.fernandez@st.com>

STMP32MP1 has 4 PLLs.
PLL supports integer and fractional mode.
Each PLL has 3 output dividers (p, q, r)

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
---
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 47984f3..d62a3a9 100644
--- a/drivers/clk/clk-stm32mp1.c
+++ b/drivers/clk/clk-stm32mp1.c
@@ -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 @@ static void mp1_gate_clk_disable(struct clk_hw *hw)
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 @@ static void mp1_gate_clk_disable(struct clk_hw *hw)
.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 void mp1_gate_clk_disable(struct clk_hw *hw)

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 {
--
1.9.1
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