drm/radeon/kms: use lcd pll limits when available

The bios has alternate pll output limits for LCD panels.
If available, use these for pll divider calculations.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -525,6 +525,7 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 				if (encoder->encoder_type == DRM_MODE_ENCODER_LVDS) {
 					struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 					pll->algo = dig->pll_algo;
+					pll->flags |= RADEON_PLL_IS_LCD;
 				}
 			} else {
 				if (encoder->encoder_type != DRM_MODE_ENCODER_DAC)

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -887,6 +887,20 @@ bool radeon_atom_get_clock_info(struct drm_device *dev)
 		p1pll->pll_out_max =
 		    le32_to_cpu(firmware_info->info.ulMaxPixelClockPLL_Output);
 
+		if (crev >= 4) {
+			p1pll->lcd_pll_out_min =
+				le16_to_cpu(firmware_info->info_14.usLcdMinPixelClockPLL_Output) * 100;
+			if (p1pll->lcd_pll_out_min == 0)
+				p1pll->lcd_pll_out_min = p1pll->pll_out_min;
+			p1pll->lcd_pll_out_max =
+				le16_to_cpu(firmware_info->info_14.usLcdMaxPixelClockPLL_Output) * 100;
+			if (p1pll->lcd_pll_out_max == 0)
+				p1pll->lcd_pll_out_max = p1pll->pll_out_max;
+		} else {
+			p1pll->lcd_pll_out_min = p1pll->pll_out_min;
+			p1pll->lcd_pll_out_max = p1pll->pll_out_max;
+		}
+
 		if (p1pll->pll_out_min == 0) {
 			if (ASIC_IS_AVIVO(rdev))
 				p1pll->pll_out_min = 64800;

drivers/gpu/drm/radeon/radeon_combios.c

@@ -633,6 +633,8 @@ bool radeon_combios_get_clock_info(struct drm_device *dev)
 		p1pll->reference_div = RBIOS16(pll_info + 0x10);
 		p1pll->pll_out_min = RBIOS32(pll_info + 0x12);
 		p1pll->pll_out_max = RBIOS32(pll_info + 0x16);
+		p1pll->lcd_pll_out_min = p1pll->pll_out_min;
+		p1pll->lcd_pll_out_max = p1pll->pll_out_max;
 
 		if (rev > 9) {
 			p1pll->pll_in_min = RBIOS32(pll_info + 0x36);

drivers/gpu/drm/radeon/radeon_display.c

@@ -469,10 +469,19 @@ static void radeon_compute_pll_legacy(struct radeon_pll *pll,
 	uint32_t best_error = 0xffffffff;
 	uint32_t best_vco_diff = 1;
 	uint32_t post_div;
+	u32 pll_out_min, pll_out_max;
 
 	DRM_DEBUG("PLL freq %llu %u %u\n", freq, pll->min_ref_div, pll->max_ref_div);
 	freq = freq * 1000;
 
+	if (pll->flags & RADEON_PLL_IS_LCD) {
+		pll_out_min = pll->lcd_pll_out_min;
+		pll_out_max = pll->lcd_pll_out_max;
+	} else {
+		pll_out_min = pll->pll_out_min;
+		pll_out_max = pll->pll_out_max;
+	}
+
 	if (pll->flags & RADEON_PLL_USE_REF_DIV)
 		min_ref_div = max_ref_div = pll->reference_div;
 	else {
@@ -536,10 +545,10 @@ static void radeon_compute_pll_legacy(struct radeon_pll *pll,
 				tmp = (uint64_t)pll->reference_freq * feedback_div;
 				vco = radeon_div(tmp, ref_div);
 
-				if (vco < pll->pll_out_min) {
+				if (vco < pll_out_min) {
 					min_feed_div = feedback_div + 1;
 					continue;
-				} else if (vco > pll->pll_out_max) {
+				} else if (vco > pll_out_max) {
 					max_feed_div = feedback_div;
 					continue;
 				}
@@ -675,6 +684,15 @@ calc_fb_ref_div(struct radeon_pll *pll,
 {
 	fixed20_12 ffreq, max_error, error, pll_out, a;
 	u32 vco;
+	u32 pll_out_min, pll_out_max;
+
+	if (pll->flags & RADEON_PLL_IS_LCD) {
+		pll_out_min = pll->lcd_pll_out_min;
+		pll_out_max = pll->lcd_pll_out_max;
+	} else {
+		pll_out_min = pll->pll_out_min;
+		pll_out_max = pll->pll_out_max;
+	}
 
 	ffreq.full = rfixed_const(freq);
 	/* max_error = ffreq * 0.0025; */
@@ -686,7 +704,7 @@ calc_fb_ref_div(struct radeon_pll *pll,
 			vco = pll->reference_freq * (((*fb_div) * 10) + (*fb_div_frac));
 			vco = vco / ((*ref_div) * 10);
 
-			if ((vco < pll->pll_out_min) || (vco > pll->pll_out_max))
+			if ((vco < pll_out_min) || (vco > pll_out_max))
 				continue;
 
 			/* pll_out = vco / post_div; */
@@ -714,6 +732,15 @@ static void radeon_compute_pll_new(struct radeon_pll *pll,
 {
 	u32 fb_div = 0, fb_div_frac = 0, post_div = 0, ref_div = 0;
 	u32 best_freq = 0, vco_frequency;
+	u32 pll_out_min, pll_out_max;
+
+	if (pll->flags & RADEON_PLL_IS_LCD) {
+		pll_out_min = pll->lcd_pll_out_min;
+		pll_out_max = pll->lcd_pll_out_max;
+	} else {
+		pll_out_min = pll->pll_out_min;
+		pll_out_max = pll->pll_out_max;
+	}
 
 	/* freq = freq / 10; */
 	do_div(freq, 10);
@@ -724,7 +751,7 @@ static void radeon_compute_pll_new(struct radeon_pll *pll,
 			goto done;
 
 		vco_frequency = freq * post_div;
-		if ((vco_frequency < pll->pll_out_min) || (vco_frequency > pll->pll_out_max))
+		if ((vco_frequency < pll_out_min) || (vco_frequency > pll_out_max))
 			goto done;
 
 		if (pll->flags & RADEON_PLL_USE_REF_DIV) {
@@ -749,7 +776,7 @@ static void radeon_compute_pll_new(struct radeon_pll *pll,
 				continue;
 
 			vco_frequency = freq * post_div;
-			if ((vco_frequency < pll->pll_out_min) || (vco_frequency > pll->pll_out_max))
+			if ((vco_frequency < pll_out_min) || (vco_frequency > pll_out_max))
 				continue;
 			if (pll->flags & RADEON_PLL_USE_REF_DIV) {
 				ref_div = pll->reference_div;

drivers/gpu/drm/radeon/radeon_mode.h

@@ -129,6 +129,7 @@ struct radeon_tmds_pll {
 #define RADEON_PLL_USE_FRAC_FB_DIV      (1 << 10)
 #define RADEON_PLL_PREFER_CLOSEST_LOWER (1 << 11)
 #define RADEON_PLL_USE_POST_DIV         (1 << 12)
+#define RADEON_PLL_IS_LCD               (1 << 13)
 
 /* pll algo */
 enum radeon_pll_algo {
@@ -149,6 +150,8 @@ struct radeon_pll {
 	uint32_t pll_in_max;
 	uint32_t pll_out_min;
 	uint32_t pll_out_max;
+	uint32_t lcd_pll_out_min;
+	uint32_t lcd_pll_out_max;
 	uint32_t best_vco;
 
 	/* divider limits */