drm: zte: add function to configure vou_ctrl dividers

The clock control module (CRM) cannot always provide desired frequency
for all VOU output devices.  That's why VOU integrates a few dividers
to further divide the clocks from CRM.  Let's add an interface for
configuring these dividers.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>

3 files changed, 120 insertions, 0 deletions

diff --git a/drivers/gpu/drm/zte/zx_vou.c b/drivers/gpu/drm/zte/zx_vou.c
index b5cbb5075b0b..2552d72708d9 100644
--- a/drivers/gpu/drm/zte/zx_vou.c
+++ b/drivers/gpu/drm/zte/zx_vou.c
@@ -72,6 +72,13 @@ struct zx_crtc_bits {
 	u32 sec_vactive_mask;
 	u32 interlace_select;
 	u32 pi_enable;
+	u32 div_vga_shift;
+	u32 div_pic_shift;
+	u32 div_tvenc_shift;
+	u32 div_hdmi_pnx_shift;
+	u32 div_hdmi_shift;
+	u32 div_inf_shift;
+	u32 div_layer_shift;
 };
 
 static const struct zx_crtc_bits main_crtc_bits = {
@@ -83,6 +90,13 @@ static const struct zx_crtc_bits main_crtc_bits = {
 	.sec_vactive_mask = SEC_VACT_MAIN_MASK,
 	.interlace_select = MAIN_INTERLACE_SEL,
 	.pi_enable = MAIN_PI_EN,
+	.div_vga_shift = VGA_MAIN_DIV_SHIFT,
+	.div_pic_shift = PIC_MAIN_DIV_SHIFT,
+	.div_tvenc_shift = TVENC_MAIN_DIV_SHIFT,
+	.div_hdmi_pnx_shift = HDMI_MAIN_PNX_DIV_SHIFT,
+	.div_hdmi_shift = HDMI_MAIN_DIV_SHIFT,
+	.div_inf_shift = INF_MAIN_DIV_SHIFT,
+	.div_layer_shift = LAYER_MAIN_DIV_SHIFT,
 };
 
 static const struct zx_crtc_bits aux_crtc_bits = {
@@ -94,6 +108,13 @@ static const struct zx_crtc_bits aux_crtc_bits = {
 	.sec_vactive_mask = SEC_VACT_AUX_MASK,
 	.interlace_select = AUX_INTERLACE_SEL,
 	.pi_enable = AUX_PI_EN,
+	.div_vga_shift = VGA_AUX_DIV_SHIFT,
+	.div_pic_shift = PIC_AUX_DIV_SHIFT,
+	.div_tvenc_shift = TVENC_AUX_DIV_SHIFT,
+	.div_hdmi_pnx_shift = HDMI_AUX_PNX_DIV_SHIFT,
+	.div_hdmi_shift = HDMI_AUX_DIV_SHIFT,
+	.div_inf_shift = INF_AUX_DIV_SHIFT,
+	.div_layer_shift = LAYER_AUX_DIV_SHIFT,
 };
 
 struct zx_crtc {
@@ -236,6 +257,64 @@ void vou_inf_disable(enum vou_inf_id id, struct drm_crtc *crtc)
 	zx_writel_mask(vou->vouctl + VOU_CLK_EN, inf->clocks_en_bits, 0);
 }
 
+void zx_vou_config_dividers(struct drm_crtc *crtc,
+			    struct vou_div_config *configs, int num)
+{
+	struct zx_crtc *zcrtc = to_zx_crtc(crtc);
+	struct zx_vou_hw *vou = zcrtc->vou;
+	const struct zx_crtc_bits *bits = zcrtc->bits;
+	int i;
+
+	/* Clear update flag bit */
+	zx_writel_mask(vou->vouctl + VOU_DIV_PARA, DIV_PARA_UPDATE, 0);
+
+	for (i = 0; i < num; i++) {
+		struct vou_div_config *cfg = configs + i;
+		u32 reg, shift;
+
+		switch (cfg->id) {
+		case VOU_DIV_VGA:
+			reg = VOU_CLK_SEL;
+			shift = bits->div_vga_shift;
+			break;
+		case VOU_DIV_PIC:
+			reg = VOU_CLK_SEL;
+			shift = bits->div_pic_shift;
+			break;
+		case VOU_DIV_TVENC:
+			reg = VOU_DIV_PARA;
+			shift = bits->div_tvenc_shift;
+			break;
+		case VOU_DIV_HDMI_PNX:
+			reg = VOU_DIV_PARA;
+			shift = bits->div_hdmi_pnx_shift;
+			break;
+		case VOU_DIV_HDMI:
+			reg = VOU_DIV_PARA;
+			shift = bits->div_hdmi_shift;
+			break;
+		case VOU_DIV_INF:
+			reg = VOU_DIV_PARA;
+			shift = bits->div_inf_shift;
+			break;
+		case VOU_DIV_LAYER:
+			reg = VOU_DIV_PARA;
+			shift = bits->div_layer_shift;
+			break;
+		default:
+			continue;
+		}
+
+		/* Each divider occupies 3 bits */
+		zx_writel_mask(vou->vouctl + reg, 0x7 << shift,
+			       cfg->val << shift);
+	}
+
+	/* Set update flag bit to get dividers effected */
+	zx_writel_mask(vou->vouctl + VOU_DIV_PARA, DIV_PARA_UPDATE,
+		       DIV_PARA_UPDATE);
+}
+
 static inline void vou_chn_set_update(struct zx_crtc *zcrtc)
 {
 	zx_writel(zcrtc->chnreg + CHN_UPDATE, 1);
diff --git a/drivers/gpu/drm/zte/zx_vou.h b/drivers/gpu/drm/zte/zx_vou.h
index 688c203d90b6..57e3c31ee6a5 100644
--- a/drivers/gpu/drm/zte/zx_vou.h
+++ b/drivers/gpu/drm/zte/zx_vou.h
@@ -36,6 +36,31 @@ void vou_inf_hdmi_audio_sel(struct drm_crtc *crtc,
 void vou_inf_enable(enum vou_inf_id id, struct drm_crtc *crtc);
 void vou_inf_disable(enum vou_inf_id id, struct drm_crtc *crtc);
 
+enum vou_div_id {
+	VOU_DIV_VGA,
+	VOU_DIV_PIC,
+	VOU_DIV_TVENC,
+	VOU_DIV_HDMI_PNX,
+	VOU_DIV_HDMI,
+	VOU_DIV_INF,
+	VOU_DIV_LAYER,
+};
+
+enum vou_div_val {
+	VOU_DIV_1 = 0,
+	VOU_DIV_2 = 1,
+	VOU_DIV_4 = 3,
+	VOU_DIV_8 = 7,
+};
+
+struct vou_div_config {
+	enum vou_div_id id;
+	enum vou_div_val val;
+};
+
+void zx_vou_config_dividers(struct drm_crtc *crtc,
+			    struct vou_div_config *configs, int num);
+
 int zx_vou_enable_vblank(struct drm_device *drm, unsigned int pipe);
 void zx_vou_disable_vblank(struct drm_device *drm, unsigned int pipe);
 
diff --git a/drivers/gpu/drm/zte/zx_vou_regs.h b/drivers/gpu/drm/zte/zx_vou_regs.h
index ae5cbce2a7a1..c066ef123434 100644
--- a/drivers/gpu/drm/zte/zx_vou_regs.h
+++ b/drivers/gpu/drm/zte/zx_vou_regs.h
@@ -176,11 +176,27 @@
 #define VOU_INF_DATA_SEL		0x08
 #define VOU_SOFT_RST			0x14
 #define VOU_CLK_SEL			0x18
+#define VGA_AUX_DIV_SHIFT		29
+#define VGA_MAIN_DIV_SHIFT		26
+#define PIC_MAIN_DIV_SHIFT		23
+#define PIC_AUX_DIV_SHIFT		20
 #define VOU_CLK_VL2_SEL			BIT(8)
 #define VOU_CLK_VL1_SEL			BIT(7)
 #define VOU_CLK_VL0_SEL			BIT(6)
 #define VOU_CLK_GL1_SEL			BIT(5)
 #define VOU_CLK_GL0_SEL			BIT(4)
+#define VOU_DIV_PARA			0x1c
+#define DIV_PARA_UPDATE			BIT(31)
+#define TVENC_AUX_DIV_SHIFT		28
+#define HDMI_AUX_PNX_DIV_SHIFT		25
+#define HDMI_MAIN_PNX_DIV_SHIFT		22
+#define HDMI_AUX_DIV_SHIFT		19
+#define HDMI_MAIN_DIV_SHIFT		16
+#define TVENC_MAIN_DIV_SHIFT		13
+#define INF_AUX_DIV_SHIFT		9
+#define INF_MAIN_DIV_SHIFT		6
+#define LAYER_AUX_DIV_SHIFT		3
+#define LAYER_MAIN_DIV_SHIFT		0
 #define VOU_CLK_REQEN			0x20
 #define VOU_CLK_EN			0x24
 #define VOU_INF_HDMI_CTRL		0x30