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From:   Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
To:     paul@crapouillou.net, mturquette@baylibre.com, sboyd@kernel.org,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org
Cc:     zhouyu@wanyeetech.com, linux-mips@vger.kernel.org,
        linux-clk@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v1 1/5] clk: ingenic: Make PLL clock "od" field optional
Date:   Sun, 23 Oct 2022 15:56:49 +0100
Message-Id: <20221023145653.177234-2-aidanmacdonald.0x0@gmail.com>
In-Reply-To: <20221023145653.177234-1-aidanmacdonald.0x0@gmail.com>
References: <20221023145653.177234-1-aidanmacdonald.0x0@gmail.com>
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Add support for defining PLL clocks with od_bits = 0, meaning that
OD is fixed to 1 and there is no OD field in the register.

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
---
 drivers/clk/ingenic/cgu.c | 28 +++++++++++++++++++---------
 drivers/clk/ingenic/cgu.h |  3 ++-
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/clk/ingenic/cgu.c b/drivers/clk/ingenic/cgu.c
index 861c50d6cb24..7dc2e2567d53 100644
--- a/drivers/clk/ingenic/cgu.c
+++ b/drivers/clk/ingenic/cgu.c
@@ -96,8 +96,11 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 	m += pll_info->m_offset;
 	n = (ctl >> pll_info->n_shift) & GENMASK(pll_info->n_bits - 1, 0);
 	n += pll_info->n_offset;
-	od_enc = ctl >> pll_info->od_shift;
-	od_enc &= GENMASK(pll_info->od_bits - 1, 0);
+
+	if (pll_info->od_bits > 0) {
+		od_enc = ctl >> pll_info->od_shift;
+		od_enc &= GENMASK(pll_info->od_bits - 1, 0);
+	}
 
 	if (pll_info->bypass_bit >= 0) {
 		ctl = readl(cgu->base + pll_info->bypass_reg);
@@ -108,12 +111,17 @@ ingenic_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 			return parent_rate;
 	}
 
-	for (od = 0; od < pll_info->od_max; od++) {
-		if (pll_info->od_encoding[od] == od_enc)
-			break;
+	if (pll_info->od_bits > 0) {
+		for (od = 0; od < pll_info->od_max; od++) {
+			if (pll_info->od_encoding[od] == od_enc)
+				break;
+		}
+		BUG_ON(od == pll_info->od_max);
+		od++;
+	} else {
+		/* OD is fixed to 1 if no OD field is present. */
+		od = 1;
 	}
-	BUG_ON(od == pll_info->od_max);
-	od++;
 
 	return div_u64((u64)parent_rate * m * pll_info->rate_multiplier,
 		n * od);
@@ -215,8 +223,10 @@ ingenic_pll_set_rate(struct clk_hw *hw, unsigned long req_rate,
 	ctl &= ~(GENMASK(pll_info->n_bits - 1, 0) << pll_info->n_shift);
 	ctl |= (n - pll_info->n_offset) << pll_info->n_shift;
 
-	ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
-	ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;
+	if (pll_info->od_bits > 0) {
+		ctl &= ~(GENMASK(pll_info->od_bits - 1, 0) << pll_info->od_shift);
+		ctl |= pll_info->od_encoding[od - 1] << pll_info->od_shift;
+	}
 
 	writel(ctl, cgu->base + pll_info->reg);
 
diff --git a/drivers/clk/ingenic/cgu.h b/drivers/clk/ingenic/cgu.h
index 147b7df0d657..567142b584bb 100644
--- a/drivers/clk/ingenic/cgu.h
+++ b/drivers/clk/ingenic/cgu.h
@@ -33,7 +33,8 @@
  * @od_shift: the number of bits to shift the post-VCO divider value by (ie.
  *            the index of the lowest bit of the post-VCO divider value in
  *            the PLL's control register)
- * @od_bits: the size of the post-VCO divider field in bits
+ * @od_bits: the size of the post-VCO divider field in bits, or 0 if no
+ *	     OD field exists (then the OD is fixed to 1)
  * @od_max: the maximum post-VCO divider value
  * @od_encoding: a pointer to an array mapping post-VCO divider values to
  *               their encoded values in the PLL control register, or -1 for
-- 
2.38.1