linux-kernel - [PATCH v3 07/13] clk: microchip: mpfs: add MSS pll's set & round rate

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Message-ID: <20220819095320.40006-8-conor.dooley@microchip.com>
Date:   Fri, 19 Aug 2022 10:53:15 +0100
From:   Conor Dooley <conor.dooley@...rochip.com>
To:     Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Palmer Dabbelt <palmer@...belt.com>,
        Conor Dooley <conor.dooley@...rochip.com>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Daire McNamara <daire.mcnamara@...rochip.com>
CC:     Paul Walmsley <paul.walmsley@...ive.com>,
        Albert Ou <aou@...s.berkeley.edu>, <linux-clk@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-riscv@...ts.infradead.org>
Subject: [PATCH v3 07/13] clk: microchip: mpfs: add MSS pll's set & round rate

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@...rochip.com>
Signed-off-by: Conor Dooley <conor.dooley@...rochip.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 1034f7d69660..3c8cd0094143 100644
--- a/drivers/clk/microchip/clk-mpfs.c
+++ b/drivers/clk/microchip/clk-mpfs.c
@@ -131,8 +131,62 @@ 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