[PATCH v5 08/14] clk: microchip: mpfs: add MSS pll's set & round rate

Conor Dooley
2022-09-09T12:32:21Z

The MSS pll is not a fixed frequency clock, so add set() & round_rate()
support.
Control is limited to a 7 bit output divider as other devices on the
FPGA occupy the other three outputs of the PLL & prevent changing
the multiplier.

Reviewed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
---
drivers/clk/microchip/clk-mpfs.c | 54 ++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
index 610c81ecc526..f40d22293539 100644
--- a/drivers/clk/microchip/clk-mpfs.c
+++ b/drivers/clk/microchip/clk-mpfs.c
@@ -129,8 +129,62 @@ static unsigned long mpfs_clk_msspll_recalc_rate(struct clk_hw *hw, unsigned lon
return prate * mult / (ref_div * MSSPLL_FIXED_DIV * postdiv);
}

+static long mpfs_clk_msspll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
+{
+ struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
+ void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
+ void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
+ u32 mult, ref_div;
+ unsigned long rate_before_ctrl;
+
+ mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
+ mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
+ ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
+ ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
+
+ rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
+
+ return divider_round_rate(hw, rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
+ msspll_hw->flags);
+}
+
+static int mpfs_clk_msspll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
+{
+ struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
+ void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
+ void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
+ void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
+ u32 mult, ref_div, postdiv;
+ int divider_setting;
+ unsigned long rate_before_ctrl, flags;
+
+ mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
+ mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
+ ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
+ ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
+
+ rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
+ divider_setting = divider_get_val(rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
+ msspll_hw->flags);
+
+ if (divider_setting < 0)
+ return divider_setting;
+
+ spin_lock_irqsave(&mpfs_clk_lock, flags);
+
+ postdiv = readl_relaxed(postdiv_addr);
+ postdiv &= ~(clk_div_mask(MSSPLL_POSTDIV_WIDTH) << MSSPLL_POSTDIV_SHIFT);
+ writel_relaxed(postdiv, postdiv_addr);
+
+ spin_unlock_irqrestore(&mpfs_clk_lock, flags);
+
+ return 0;
+}
+
static const struct clk_ops mpfs_clk_msspll_ops = {
.recalc_rate = mpfs_clk_msspll_recalc_rate,
+ .round_rate = mpfs_clk_msspll_round_rate,
+ .set_rate = mpfs_clk_msspll_set_rate,
};

#define CLK_PLL(_id, _name, _parent, _shift, _width, _flags, _offset) { \
--
2.36.1