drm/bridge: analogix_dp: add the PSR function support

The full name of PSR is Panel Self Refresh, panel device could refresh
itself with the hardware framebuffer in panel, this would make lots of
sense to save the power consumption.

This patch have exported two symbols for platform driver to implement
the PSR function in hardware side:
- analogix_dp_active_psr()
- analogix_dp_inactive_psr()
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>

drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

@@ -97,6 +97,83 @@ static int analogix_dp_detect_hpd(struct analogix_dp_device *dp)
 	return 0;
 }
 
+int analogix_dp_enable_psr(struct device *dev)
+{
+	struct analogix_dp_device *dp = dev_get_drvdata(dev);
+	struct edp_vsc_psr psr_vsc;
+
+	if (!dp->psr_support)
+		return -EINVAL;
+
+	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
+	memset(&psr_vsc, 0, sizeof(psr_vsc));
+	psr_vsc.sdp_header.HB0 = 0;
+	psr_vsc.sdp_header.HB1 = 0x7;
+	psr_vsc.sdp_header.HB2 = 0x2;
+	psr_vsc.sdp_header.HB3 = 0x8;
+
+	psr_vsc.DB0 = 0;
+	psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
+
+	analogix_dp_send_psr_spd(dp, &psr_vsc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
+
+int analogix_dp_disable_psr(struct device *dev)
+{
+	struct analogix_dp_device *dp = dev_get_drvdata(dev);
+	struct edp_vsc_psr psr_vsc;
+
+	if (!dp->psr_support)
+		return -EINVAL;
+
+	/* Prepare VSC packet as per EDP 1.4 spec, Table 6.9 */
+	memset(&psr_vsc, 0, sizeof(psr_vsc));
+	psr_vsc.sdp_header.HB0 = 0;
+	psr_vsc.sdp_header.HB1 = 0x7;
+	psr_vsc.sdp_header.HB2 = 0x2;
+	psr_vsc.sdp_header.HB3 = 0x8;
+
+	psr_vsc.DB0 = 0;
+	psr_vsc.DB1 = 0;
+
+	analogix_dp_send_psr_spd(dp, &psr_vsc);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
+
+static bool analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
+{
+	unsigned char psr_version;
+
+	analogix_dp_read_byte_from_dpcd(dp, DP_PSR_SUPPORT, &psr_version);
+	dev_dbg(dp->dev, "Panel PSR version : %x\n", psr_version);
+
+	return (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
+}
+
+static void analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
+{
+	unsigned char psr_en;
+
+	/* Disable psr function */
+	analogix_dp_read_byte_from_dpcd(dp, DP_PSR_EN_CFG, &psr_en);
+	psr_en &= ~DP_PSR_ENABLE;
+	analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
+
+	/* Main-Link transmitter remains active during PSR active states */
+	psr_en = DP_PSR_MAIN_LINK_ACTIVE | DP_PSR_CRC_VERIFICATION;
+	analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
+
+	/* Enable psr function */
+	psr_en = DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE |
+		 DP_PSR_CRC_VERIFICATION;
+	analogix_dp_write_byte_to_dpcd(dp, DP_PSR_EN_CFG, psr_en);
+
+	analogix_dp_enable_psr_crc(dp);
+}
+
 static unsigned char analogix_dp_calc_edid_check_sum(unsigned char *edid_data)
 {
 	int i;
@@ -921,6 +998,10 @@ static void analogix_dp_commit(struct analogix_dp_device *dp)
 
 	/* Enable video */
 	analogix_dp_start_video(dp);
+
+	dp->psr_support = analogix_dp_detect_sink_psr(dp);
+	if (dp->psr_support)
+		analogix_dp_enable_sink_psr(dp);
 }
 
 /*

drivers/gpu/drm/bridge/analogix/analogix_dp_core.h

@@ -177,6 +177,7 @@ struct analogix_dp_device {
 	int			hpd_gpio;
 	bool                    force_hpd;
 	unsigned char           edid[EDID_BLOCK_LENGTH * 2];
+	bool			psr_support;
 
 	struct mutex		panel_lock;
 	bool			panel_is_modeset;
@@ -281,4 +282,8 @@ int analogix_dp_is_video_stream_on(struct analogix_dp_device *dp);
 void analogix_dp_config_video_slave_mode(struct analogix_dp_device *dp);
 void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
 void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
+void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
+void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			      struct edp_vsc_psr *vsc);
+
 #endif /* _ANALOGIX_DP_CORE_H */

drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c

@@ -1322,3 +1322,54 @@ void analogix_dp_disable_scrambling(struct analogix_dp_device *dp)
 	reg |= SCRAMBLING_DISABLE;
 	writel(reg, dp->reg_base + ANALOGIX_DP_TRAINING_PTN_SET);
 }
+
+void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
+{
+	writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
+}
+
+void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
+			      struct edp_vsc_psr *vsc)
+{
+	unsigned int val;
+
+	/* don't send info frame */
+	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+	val &= ~IF_EN;
+	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+
+	/* configure single frame update mode */
+	writel(PSR_FRAME_UP_TYPE_BURST | PSR_CRC_SEL_HARDWARE,
+	       dp->reg_base + ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL);
+
+	/* configure VSC HB0~HB3 */
+	writel(vsc->sdp_header.HB0, dp->reg_base + ANALOGIX_DP_SPD_HB0);
+	writel(vsc->sdp_header.HB1, dp->reg_base + ANALOGIX_DP_SPD_HB1);
+	writel(vsc->sdp_header.HB2, dp->reg_base + ANALOGIX_DP_SPD_HB2);
+	writel(vsc->sdp_header.HB3, dp->reg_base + ANALOGIX_DP_SPD_HB3);
+
+	/* configure reused VSC PB0~PB3, magic number from vendor */
+	writel(0x00, dp->reg_base + ANALOGIX_DP_SPD_PB0);
+	writel(0x16, dp->reg_base + ANALOGIX_DP_SPD_PB1);
+	writel(0xCE, dp->reg_base + ANALOGIX_DP_SPD_PB2);
+	writel(0x5D, dp->reg_base + ANALOGIX_DP_SPD_PB3);
+
+	/* configure DB0 / DB1 values */
+	writel(vsc->DB0, dp->reg_base + ANALOGIX_DP_VSC_SHADOW_DB0);
+	writel(vsc->DB1, dp->reg_base + ANALOGIX_DP_VSC_SHADOW_DB1);
+
+	/* set reuse spd inforframe */
+	val = readl(dp->reg_base + ANALOGIX_DP_VIDEO_CTL_3);
+	val |= REUSE_SPD_EN;
+	writel(val, dp->reg_base + ANALOGIX_DP_VIDEO_CTL_3);
+
+	/* mark info frame update */
+	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+	val = (val | IF_UP) & ~IF_EN;
+	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+
+	/* send info frame */
+	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+	val |= IF_EN;
+	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
+}

drivers/gpu/drm/bridge/analogix/analogix_dp_reg.h

@@ -22,6 +22,8 @@
 #define ANALOGIX_DP_VIDEO_CTL_8			0x3C
 #define ANALOGIX_DP_VIDEO_CTL_10		0x44
 
+#define ANALOGIX_DP_SPDIF_AUDIO_CTL_0		0xD8
+
 #define ANALOGIX_DP_PLL_REG_1			0xfc
 #define ANALOGIX_DP_PLL_REG_2			0x9e4
 #define ANALOGIX_DP_PLL_REG_3			0x9e8
@@ -30,6 +32,21 @@
 
 #define ANALOGIX_DP_PD				0x12c
 
+#define ANALOGIX_DP_IF_TYPE			0x244
+#define ANALOGIX_DP_IF_PKT_DB1			0x254
+#define ANALOGIX_DP_IF_PKT_DB2			0x258
+#define ANALOGIX_DP_SPD_HB0			0x2F8
+#define ANALOGIX_DP_SPD_HB1			0x2FC
+#define ANALOGIX_DP_SPD_HB2			0x300
+#define ANALOGIX_DP_SPD_HB3			0x304
+#define ANALOGIX_DP_SPD_PB0			0x308
+#define ANALOGIX_DP_SPD_PB1			0x30C
+#define ANALOGIX_DP_SPD_PB2			0x310
+#define ANALOGIX_DP_SPD_PB3			0x314
+#define ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL	0x318
+#define ANALOGIX_DP_VSC_SHADOW_DB0		0x31C
+#define ANALOGIX_DP_VSC_SHADOW_DB1		0x320
+
 #define ANALOGIX_DP_LANE_MAP			0x35C
 
 #define ANALOGIX_DP_ANALOG_CTL_1		0x370
@@ -103,6 +120,8 @@
 
 #define ANALOGIX_DP_SOC_GENERAL_CTL		0x800
 
+#define ANALOGIX_DP_CRC_CON			0x890
+
 /* ANALOGIX_DP_TX_SW_RESET */
 #define RESET_DP_TX				(0x1 << 0)
 
@@ -151,6 +170,7 @@
 #define VID_CHK_UPDATE_TYPE_SHIFT		(4)
 #define VID_CHK_UPDATE_TYPE_1			(0x1 << 4)
 #define VID_CHK_UPDATE_TYPE_0			(0x0 << 4)
+#define REUSE_SPD_EN				(0x1 << 3)
 
 /* ANALOGIX_DP_VIDEO_CTL_8 */
 #define VID_HRES_TH(x)				(((x) & 0xf) << 4)
@@ -167,6 +187,12 @@
 #define REF_CLK_27M				(0x0 << 0)
 #define REF_CLK_MASK				(0x1 << 0)
 
+/* ANALOGIX_DP_PSR_FRAME_UPDATE_CTRL */
+#define PSR_FRAME_UP_TYPE_BURST			(0x1 << 0)
+#define PSR_FRAME_UP_TYPE_SINGLE		(0x0 << 0)
+#define PSR_CRC_SEL_HARDWARE			(0x1 << 1)
+#define PSR_CRC_SEL_MANUALLY			(0x0 << 1)
+
 /* ANALOGIX_DP_LANE_MAP */
 #define LANE3_MAP_LOGIC_LANE_0			(0x0 << 6)
 #define LANE3_MAP_LOGIC_LANE_1			(0x1 << 6)
@@ -376,4 +402,12 @@
 #define VIDEO_MODE_SLAVE_MODE			(0x1 << 0)
 #define VIDEO_MODE_MASTER_MODE			(0x0 << 0)
 
+/* ANALOGIX_DP_PKT_SEND_CTL */
+#define IF_UP					(0x1 << 4)
+#define IF_EN					(0x1 << 0)
+
+/* ANALOGIX_DP_CRC_CON */
+#define PSR_VID_CRC_FLUSH			(0x1 << 2)
+#define PSR_VID_CRC_ENABLE			(0x1 << 0)
+
 #endif /* _ANALOGIX_DP_REG_H */

include/drm/bridge/analogix_dp.h

@@ -38,6 +38,9 @@ struct analogix_dp_plat_data {
 			 struct drm_connector *);
 };
 
+int analogix_dp_enable_psr(struct device *dev);
+int analogix_dp_disable_psr(struct device *dev);
+
 int analogix_dp_resume(struct device *dev);
 int analogix_dp_suspend(struct device *dev);