Thread (14 messages) 14 messages, 3 authors, 2024-08-08

Re: [PATCH v2 6/7] clk: samsung: clk-pll: Add support for pll_1418x

From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2024-08-08 09:39:28
Also in: linux-clk, linux-devicetree, linux-samsung-soc, lkml

On 06/08/2024 14:11, David Virag wrote:
quoted hunk ↗ jump to hunk
pll1418x is used in Exynos7885 SoC for USB PHY clock.
Operation-wise it is very similar to pll0822x, except that MDIV is only
9 bits wide instead of 10, and we use the CON1 register in the PLL
macro's "con" parameter instead of CON3 like this:

	PLL(pll_1418x, CLK_FOUT_USB_PLL, "fout_usb_pll", "oscclk",
	    PLL_LOCKTIME_PLL_USB, PLL_CON0_PLL_USB,
	    pll_usb_rate_table),

Technically the PLL should work fine with pll0822x code if the PLL
tables are correct, but it's more "correct" to actually update the mask.

Signed-off-by: David Virag <redacted>
---
 drivers/clk/samsung/clk-pll.c | 20 ++++++++++++++++----
 drivers/clk/samsung/clk-pll.h |  1 +
 2 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/samsung/clk-pll.c b/drivers/clk/samsung/clk-pll.c
index 4be879ab917e..c61a2810737c 100644
--- a/drivers/clk/samsung/clk-pll.c
+++ b/drivers/clk/samsung/clk-pll.c
@@ -430,6 +430,9 @@ static const struct clk_ops samsung_pll36xx_clk_min_ops = {
 #define PLL0822X_LOCK_STAT_SHIFT	(29)
 #define PLL0822X_ENABLE_SHIFT		(31)
 
+/* PLL1418x is similar to PLL0822x, except that MDIV is one bit smaller */
+#define PLL1418X_MDIV_MASK		(0x1FF)
+
 static unsigned long samsung_pll0822x_recalc_rate(struct clk_hw *hw,
 						  unsigned long parent_rate)
 {
@@ -438,7 +441,10 @@ static unsigned long samsung_pll0822x_recalc_rate(struct clk_hw *hw,
 	u64 fvco = parent_rate;
 
 	pll_con3 = readl_relaxed(pll->con_reg);
-	mdiv = (pll_con3 >> PLL0822X_MDIV_SHIFT) & PLL0822X_MDIV_MASK;
+	if (pll->type != pll_1418x)
+		mdiv = (pll_con3 >> PLL0822X_MDIV_SHIFT) & PLL0822X_MDIV_MASK;
+	else
+		mdiv = (pll_con3 >> PLL0822X_MDIV_SHIFT) & PLL1418X_MDIV_MASK;
 	pdiv = (pll_con3 >> PLL0822X_PDIV_SHIFT) & PLL0822X_PDIV_MASK;
 	sdiv = (pll_con3 >> PLL0822X_SDIV_SHIFT) & PLL0822X_SDIV_MASK;
 
@@ -468,9 +474,14 @@ static int samsung_pll0822x_set_rate(struct clk_hw *hw, unsigned long drate,
 
 	/* Change PLL PMS values */
 	pll_con3 = readl_relaxed(pll->con_reg);
-	pll_con3 &= ~((PLL0822X_MDIV_MASK << PLL0822X_MDIV_SHIFT) |
-			(PLL0822X_PDIV_MASK << PLL0822X_PDIV_SHIFT) |
-			(PLL0822X_SDIV_MASK << PLL0822X_SDIV_SHIFT));
+	if (pll->type != pll_1418x)
+		pll_con3 &= ~((PLL0822X_MDIV_MASK << PLL0822X_MDIV_SHIFT) |
+				(PLL0822X_PDIV_MASK << PLL0822X_PDIV_SHIFT) |
+				(PLL0822X_SDIV_MASK << PLL0822X_SDIV_SHIFT));
I think this part could be simpler. If I read it correctly, only mdiv
mask is different, so create local variable mdiv_mask and set it in
if-else block accordingly to the type. Then here you have
non-conditional code:
pll_con3 &= ~((mdiv_mask << PLL0822X_MDIV_SHIFT) |



Best regards,
Krzysztof

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