drm: bridge/dw_hdmi: clean up phy configuration

The phy configuration is dependent on the SoC, and we look up values for
some of the registers in SoC specific data.  However, we had partially
programmed the phy before we had successfully looked up the clock rate.
Also, we were only checking that we had a valid configuration for the
currctrl register.

Move all these lookups to the start of this function instead, so we can
check that all lookups were successful before beginning to program the
phy.

Tested-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/gpu/drm/bridge/dw_hdmi.c

@@ -753,12 +753,12 @@ static void dw_hdmi_phy_sel_interface_control(struct dw_hdmi *hdmi, u8 enable)
 static int hdmi_phy_configure(struct dw_hdmi *hdmi, unsigned char prep,
 			      unsigned char res, int cscon)
 {
-	unsigned res_idx, i;
+	unsigned res_idx;
 	u8 val, msec;
-	const struct dw_hdmi_plat_data *plat_data = hdmi->plat_data;
-	const struct dw_hdmi_mpll_config *mpll_config = plat_data->mpll_cfg;
-	const struct dw_hdmi_curr_ctrl *curr_ctrl = plat_data->cur_ctr;
-	const struct dw_hdmi_phy_config *phy_config = plat_data->phy_config;
+	const struct dw_hdmi_plat_data *pdata = hdmi->plat_data;
+	const struct dw_hdmi_mpll_config *mpll_config = pdata->mpll_cfg;
+	const struct dw_hdmi_curr_ctrl *curr_ctrl = pdata->cur_ctr;
+	const struct dw_hdmi_phy_config *phy_config = pdata->phy_config;
 
 	if (prep)
 		return -EINVAL;
@@ -778,6 +778,30 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi, unsigned char prep,
 		return -EINVAL;
 	}
 
+	/* PLL/MPLL Cfg - always match on final entry */
+	for (; mpll_config->mpixelclock != ~0UL; mpll_config++)
+		if (hdmi->hdmi_data.video_mode.mpixelclock <=
+		    mpll_config->mpixelclock)
+			break;
+
+	for (; curr_ctrl->mpixelclock != ~0UL; curr_ctrl++)
+		if (hdmi->hdmi_data.video_mode.mpixelclock <=
+		    curr_ctrl->mpixelclock)
+			break;
+
+	for (; phy_config->mpixelclock != ~0UL; phy_config++)
+		if (hdmi->hdmi_data.video_mode.mpixelclock <=
+		    phy_config->mpixelclock)
+			break;
+
+	if (mpll_config->mpixelclock == ~0UL ||
+	    curr_ctrl->mpixelclock == ~0UL ||
+	    phy_config->mpixelclock == ~0UL) {
+		dev_err(hdmi->dev, "Pixel clock %d - unsupported by HDMI\n",
+			hdmi->hdmi_data.video_mode.mpixelclock);
+		return -EINVAL;
+	}
+
 	/* Enable csc path */
 	if (cscon)
 		val = HDMI_MC_FLOWCTRL_FEED_THROUGH_OFF_CSC_IN_PATH;
@@ -803,40 +827,18 @@ static int hdmi_phy_configure(struct dw_hdmi *hdmi, unsigned char prep,
 		    HDMI_PHY_I2CM_SLAVE_ADDR);
 	hdmi_phy_test_clear(hdmi, 0);
 
-	/* PLL/MPLL Cfg - always match on final entry */
-	for (i = 0; mpll_config[i].mpixelclock != (~0UL); i++)
-		if (hdmi->hdmi_data.video_mode.mpixelclock <=
-		    mpll_config[i].mpixelclock)
-			break;
-
-	hdmi_phy_i2c_write(hdmi, mpll_config[i].res[res_idx].cpce, 0x06);
-	hdmi_phy_i2c_write(hdmi, mpll_config[i].res[res_idx].gmp, 0x15);
-
-	for (i = 0; curr_ctrl[i].mpixelclock != (~0UL); i++)
-		if (hdmi->hdmi_data.video_mode.mpixelclock <=
-		    curr_ctrl[i].mpixelclock)
-			break;
-
-	if (curr_ctrl[i].mpixelclock == (~0UL)) {
-		dev_err(hdmi->dev, "Pixel clock %d - unsupported by HDMI\n",
-			hdmi->hdmi_data.video_mode.mpixelclock);
-		return -EINVAL;
-	}
+	hdmi_phy_i2c_write(hdmi, mpll_config->res[res_idx].cpce, 0x06);
+	hdmi_phy_i2c_write(hdmi, mpll_config->res[res_idx].gmp, 0x15);
 
 	/* CURRCTRL */
-	hdmi_phy_i2c_write(hdmi, curr_ctrl[i].curr[res_idx], 0x10);
+	hdmi_phy_i2c_write(hdmi, curr_ctrl->curr[res_idx], 0x10);
 
 	hdmi_phy_i2c_write(hdmi, 0x0000, 0x13);  /* PLLPHBYCTRL */
 	hdmi_phy_i2c_write(hdmi, 0x0006, 0x17);
 
-	for (i = 0; phy_config[i].mpixelclock != (~0UL); i++)
-		if (hdmi->hdmi_data.video_mode.mpixelclock <=
-		    phy_config[i].mpixelclock)
-			break;
-
-	hdmi_phy_i2c_write(hdmi, phy_config[i].term, 0x19);  /* TXTERM */
-	hdmi_phy_i2c_write(hdmi, phy_config[i].sym_ctr, 0x09); /* CKSYMTXCTRL */
-	hdmi_phy_i2c_write(hdmi, phy_config[i].vlev_ctr, 0x0E); /* VLEVCTRL */
+	hdmi_phy_i2c_write(hdmi, phy_config->term, 0x19);  /* TXTERM */
+	hdmi_phy_i2c_write(hdmi, phy_config->sym_ctr, 0x09); /* CKSYMTXCTRL */
+	hdmi_phy_i2c_write(hdmi, phy_config->vlev_ctr, 0x0E); /* VLEVCTRL */
 
 	/* REMOVE CLK TERM */
 	hdmi_phy_i2c_write(hdmi, 0x8000, 0x05);  /* CKCALCTRL */