linux-kernel - [PATCH v2] phy: mediatek: rework the floating point comparisons to fixed point

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Message-Id: <20230502145005.2927101-1-trix@redhat.com>
Date:   Tue,  2 May 2023 10:50:05 -0400
From:   Tom Rix <trix@...hat.com>
To:     chunkuang.hu@...nel.org, p.zabel@...gutronix.de,
        chunfeng.yun@...iatek.com, vkoul@...nel.org, kishon@...nel.org,
        matthias.bgg@...il.com, angelogioacchino.delregno@...labora.com
Cc:     dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-phy@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Tom Rix <trix@...hat.com>
Subject: [PATCH v2] phy: mediatek: rework the floating point comparisons to fixed point

gcc on aarch64 reports
drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c: In function ‘mtk_hdmi_pll_set_rate’:
drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c:240:52: error: ‘-mgeneral-regs-only’
  is incompatible with the use of floating-point types
  240 |         else if (tmds_clk >= 54 * MEGA && tmds_clk < 148.35 * MEGA)

Floating point should not be used, so rework the floating point comparisons
to fixed point.

Signed-off-by: Tom Rix <trix@...hat.com>
---
v2: silence robot by casting types to u64

---
drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c b/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
index abfc077fb0a8..093c4d1da557 100644
--- a/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
+++ b/drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c
@@ -237,11 +237,11 @@ static int mtk_hdmi_pll_calc(struct mtk_hdmi_phy *hdmi_phy, struct clk_hw *hw,
 	 */
 	if (tmds_clk < 54 * MEGA)
 		txposdiv = 8;
-	else if (tmds_clk >= 54 * MEGA && tmds_clk < 148.35 * MEGA)
+	else if (tmds_clk >= 54 * MEGA && (tmds_clk * 100) < 14835 * MEGA)
 		txposdiv = 4;
-	else if (tmds_clk >= 148.35 * MEGA && tmds_clk < 296.7 * MEGA)
+	else if ((tmds_clk * 100) >= 14835 * MEGA && (tmds_clk * 10) < 2967 * MEGA)
 		txposdiv = 2;
-	else if (tmds_clk >= 296.7 * MEGA && tmds_clk <= 594 * MEGA)
+	else if ((tmds_clk * 10) >= 2967 * MEGA && tmds_clk <= 594 * MEGA)
 		txposdiv = 1;
 	else
 		return -EINVAL;
@@ -328,12 +328,12 @@ static int mtk_hdmi_pll_drv_setting(struct clk_hw *hw)
 		clk_channel_bias = 0x34; /* 20mA */
 		impedance_en = 0xf;
 		impedance = 0x36; /* 100ohm */
-	} else if (pixel_clk >= 74.175 * MEGA && pixel_clk <= 300 * MEGA) {
+	} else if (((u64)pixel_clk * 1000) >= 74175 * MEGA && pixel_clk <= 300 * MEGA) {
 		data_channel_bias = 0x34; /* 20mA */
 		clk_channel_bias = 0x2c; /* 16mA */
 		impedance_en = 0xf;
 		impedance = 0x36; /* 100ohm */
-	} else if (pixel_clk >= 27 * MEGA && pixel_clk < 74.175 * MEGA) {
+	} else if (pixel_clk >= 27 * MEGA && ((u64)pixel_clk * 1000) < 74175 * MEGA) {
 		data_channel_bias = 0x14; /* 10mA */
 		clk_channel_bias = 0x14; /* 10mA */
 		impedance_en = 0x0;
-- 
2.27.0