phy: freescale: fsl-samsung-hdmi: Limit PLL lock detection clock divider to valid range

FIELD_PREP() checks that a value fits into the available bitfield,
but the index div equals to 4,is out of range.

which gcc complains about:
In function ‘fsl_samsung_hdmi_phy_configure_pll_lock_det’,
inlined from ‘fsl_samsung_hdmi_phy_configure’ at
drivers/phy/freescale/phy-fsl-samsung-hdmi.c :470:2:
././include/linux/compiler_types.h:542:38: error: call to ‘__compiletime_assert_538’
declared with attribute error: FIELD_PREP: value too large for the field
  542 |  _compiletime_assert(condition, msg, __compiletime_assert_,
__COUNTER__)
      |                                      ^
././include/linux/compiler_types.h:523:4: note: in definition of
macro ‘__compiletime_assert’ 523 |    prefix ## suffix();
      |    ^~~~~~
././include/linux/compiler_types.h:542:2: note: in expansion of macro
‘_compiletime_assert’
  542 |  _compiletime_assert(condition, msg, __compiletime_assert_,
 __COUNTER__)

REG12_CK_DIV_MASK only two bit, limit div to range 0~3,
so build error will fix.

Fixes: d567679 ("phy: freescale: fsl-samsung-hdmi: Clean up fld_tg_code calculation")
Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>

Changlog:

Reviewed-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/tencent_6F503D43467AA99DD8CC59B8F645F0725B0A@qq.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: Pei Xiao

drivers/phy/freescale/phy-fsl-samsung-hdmi.c

@@ -325,7 +325,7 @@ to_fsl_samsung_hdmi_phy(struct clk_hw *hw)
 	return container_of(hw, struct fsl_samsung_hdmi_phy, hw);
 }
 
-static void
+static int
 fsl_samsung_hdmi_phy_configure_pll_lock_det(struct fsl_samsung_hdmi_phy *phy,
 					    const struct phy_config *cfg)
 {
@@ -341,6 +341,9 @@ fsl_samsung_hdmi_phy_configure_pll_lock_det(struct fsl_samsung_hdmi_phy *phy,
 			break;
 	}
 
+	if (unlikely(div == 4))
+		return -EINVAL;
+
 	writeb(FIELD_PREP(REG12_CK_DIV_MASK, div), phy->regs + PHY_REG(12));
 
 	/*
@@ -364,6 +367,8 @@ fsl_samsung_hdmi_phy_configure_pll_lock_det(struct fsl_samsung_hdmi_phy *phy,
 	       FIELD_PREP(REG14_RP_CODE_MASK, 2) |
 	       FIELD_PREP(REG14_TG_CODE_HIGH_MASK, fld_tg_code >> 8),
 	       phy->regs + PHY_REG(14));
+
+	return 0;
 }
 
 static unsigned long fsl_samsung_hdmi_phy_find_pms(unsigned long fout, u8 *p, u16 *m, u8 *s)
@@ -466,7 +471,11 @@ static int fsl_samsung_hdmi_phy_configure(struct fsl_samsung_hdmi_phy *phy,
 	writeb(REG21_SEL_TX_CK_INV | FIELD_PREP(REG21_PMS_S_MASK,
 	       cfg->pll_div_regs[2] >> 4), phy->regs + PHY_REG(21));
 
-	fsl_samsung_hdmi_phy_configure_pll_lock_det(phy, cfg);
+	ret = fsl_samsung_hdmi_phy_configure_pll_lock_det(phy, cfg);
+	if (ret) {
+		dev_err(phy->dev, "pixclock too large\n");
+		return ret;
+	}
 
 	writeb(REG33_FIX_DA | REG33_MODE_SET_DONE, phy->regs + PHY_REG(33));