linux-kernel - [RFC V3 2/3] phy: freescale: fsl-samsung-hdmi: Simplify REG21_PMS_S

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Message-ID: <20240830032442.226031-2-aford173@gmail.com>
Date: Thu, 29 Aug 2024 22:24:26 -0500
From: Adam Ford <aford173@...il.com>
To: linux-phy@...ts.infradead.org
Cc: dominique.martinet@...ark-techno.com,
	linux-imx@....com,
	festevam@...il.com,
	frieder.schrempf@...tron.de,
	aford@...conembedded.com,
	Adam Ford <aford173@...il.com>,
	Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	Lucas Stach <l.stach@...gutronix.de>,
	Marco Felsch <m.felsch@...gutronix.de>,
	Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
	linux-kernel@...r.kernel.org
Subject: [RFC V3 2/3] phy: freescale: fsl-samsung-hdmi: Simplify REG21_PMS_S_MASK lookup

The value of 'S' is writen to two places, PHY_REG3[7:4] and
PHY_REG21[3:0].  There is a lookup table which contains
the value of PHY_REG3.  Rather than using a switch statement
based on the pixel clock to search for the value of 'S' again,
just shift the contents of PHY_REG3[7:4] >> 4 and place the value
in PHY_REG21[3:0].  Doing this can eliminate an entire function.

Signed-off-by: Adam Ford <aford173@...il.com>
---
V3: New to series

diff --git a/drivers/phy/freescale/phy-fsl-samsung-hdmi.c b/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
index bc5d3625ece6..a700a300dc6f 100644
--- a/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
+++ b/drivers/phy/freescale/phy-fsl-samsung-hdmi.c
@@ -355,40 +355,6 @@ to_fsl_samsung_hdmi_phy(struct clk_hw *hw)
 	return container_of(hw, struct fsl_samsung_hdmi_phy, hw);
 }
 
-static void
-fsl_samsung_hdmi_phy_configure_pixclk(struct fsl_samsung_hdmi_phy *phy,
-				      const struct phy_config *cfg)
-{
-	u8 div = 0x1;
-
-	switch (cfg->pixclk) {
-	case  22250000 ...  33750000:
-		div = 0xf;
-		break;
-	case  35000000 ...  40000000:
-		div = 0xb;
-		break;
-	case  43200000 ...  47500000:
-		div = 0x9;
-		break;
-	case  50349650 ...  63500000:
-		div = 0x7;
-		break;
-	case  67500000 ...  90000000:
-		div = 0x5;
-		break;
-	case  94000000 ... 148500000:
-		div = 0x3;
-		break;
-	case 154000000 ... 297000000:
-		div = 0x1;
-		break;
-	}
-
-	writeb(REG21_SEL_TX_CK_INV | FIELD_PREP(REG21_PMS_S_MASK, div),
-	       phy->regs + PHY_REG(21));
-}
-
 static void
 fsl_samsung_hdmi_phy_configure_pll_lock_det(struct fsl_samsung_hdmi_phy *phy,
 					    const struct phy_config *cfg)
@@ -457,7 +423,10 @@ static int fsl_samsung_hdmi_phy_configure(struct fsl_samsung_hdmi_phy *phy,
 	for (i = 0; i < PHY_PLL_DIV_REGS_NUM; i++)
 		writeb(cfg->pll_div_regs[i], phy->regs + PHY_REG(2) + i * 4);
 
-	fsl_samsung_hdmi_phy_configure_pixclk(phy, cfg);
+	/* High nibble of pll_div_regs[1] contains S which also gets written to REG21 */
+	writeb(REG21_SEL_TX_CK_INV | FIELD_PREP(REG21_PMS_S_MASK,
+	       cfg->pll_div_regs[1] >> 4), phy->regs + PHY_REG(21));
+
 	fsl_samsung_hdmi_phy_configure_pll_lock_det(phy, cfg);
 
 	writeb(REG33_FIX_DA | REG33_MODE_SET_DONE, phy->regs + PHY_REG(33));
-- 
2.43.0