rockchip: rk3399: check vop status when we wait dma finish flag

When vop is disabled and we read the vop register the system will
hang, so check vop status when we wait for the DMA finish flag to
avoid this sitiuation. This is done by checking for standby, DMA stop
mode, and disabled window states. Any one of these will prevent the
DMA finish flag from triggering.
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: Derek Basehore <dbasehore@chromium.org>

plat/rockchip/rk3399/drivers/m0/src/dram.c

@@ -86,12 +86,17 @@
 /* VOP */
 #define VOP_SYS_CTRL		0x8
 #define VOP_SYS_CTRL1		0xc
+#define VOP_WIN0_CTRL0		0x30
 #define	VOP_INTR_CLEAR0		0x284
 #define VOP_INTR_RAW_STATUS0	0x28c
 
 /* VOP_SYS_CTRL */
+#define VOP_DMA_STOP_EN		(1 << 21)
 #define VOP_STANDBY_EN		(1 << 22)
 
+/* VOP_WIN0_CTRL0 */
+#define WB_ENABLE		(1 << 0)
+
 /* VOP_INTR_CLEAR0 */
 #define	INT_CLR_DMA_FINISH	(1 << 15)
 #define INT_CLR_LINE_FLAG1	(1 << 4)
@@ -107,65 +112,72 @@
 #define CIC_CTRL1		0x4
 #define CIC_STATUS0		0x10
 
-struct ddr_freq_param {
-	uint32_t vop_big_en;
-	uint32_t vop_lit_en;
-	uint32_t dclk0_div;
-	uint32_t dclk1_div;
-};
-
-static struct ddr_freq_param rk3399_ddr_arg;
-
-static void get_vop_status(void)
+static inline int check_dma_status(uint32_t vop_addr, uint32_t *clr_dma_flag)
 {
-	rk3399_ddr_arg.vop_big_en = 0;
-	rk3399_ddr_arg.vop_lit_en = 0;
-
-	if ((mmio_read_32(PMU_BASE + PMU_PWRDN_ST) & PD_VOP_PWR_STAT) == 0) {
-		/* get vop0 status */
-		if ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE10_CON) &
-				  (DCLK_VOP0_SRC_EN | ACLK_VOP0_PRE_SRC_EN |
-				   HCLK_VOP0_PRE_EN)) == 0)
-			if ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE28_CON) &
-					 (HCLK_VOP0_EN | ACLK_VOP0_EN)) == 0)
-				if ((mmio_read_32(VOP_BIG_BASE_ADDR +
-						  VOP_SYS_CTRL) &
-						  VOP_STANDBY_EN) == 0)
-					rk3399_ddr_arg.vop_big_en = 1;
-
-		/* get vop1 satus */
-		if ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE10_CON) &
-				  (DCLK_VOP1_SRC_EN | ACLK_VOP1_PRE_SRC_EN |
-				   HCLK_VOP1_PRE_EN)) == 0)
-			if ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE28_CON) &
-					  (HCLK_VOP1_EN | ACLK_VOP1_EN)) == 0)
-				if ((mmio_read_32(VOP_LITE_BASE_ADDR +
-						  VOP_SYS_CTRL) &
-						  VOP_STANDBY_EN) == 0)
-					rk3399_ddr_arg.vop_lit_en = 1;
+	if (*clr_dma_flag) {
+		mmio_write_32(vop_addr + VOP_INTR_CLEAR0, 0x80008000);
+		*clr_dma_flag = 0;
 	}
-}
 
-static void wait_vop_dma_finish(void)
-{
-	uint32_t vop_adr;
+	if ((mmio_read_32(vop_addr + VOP_SYS_CTRL) &
+	     (VOP_STANDBY_EN | VOP_DMA_STOP_EN)) ||
+	    !(mmio_read_32(vop_addr + VOP_WIN0_CTRL0) & WB_ENABLE) ||
+	    (mmio_read_32(vop_addr + VOP_INTR_RAW_STATUS0) &
+	    INT_RAW_STATUS_DMA_FINISH))
+		return 1;
 
-	get_vop_status();
+	return 0;
+}
 
-	if (rk3399_ddr_arg.vop_big_en)
-		vop_adr = VOP_BIG_BASE_ADDR;
-	else if (rk3399_ddr_arg.vop_lit_en)
-		vop_adr = VOP_LITE_BASE_ADDR;
-	else
+static int wait_vop_dma_finish(void)
+{
+	uint32_t clr_dma_flag = 1;
+	uint32_t ret = 0;
+
+	stopwatch_init_usecs_expire(60000);
+	while (((mmio_read_32(PMU_BASE + PMU_PWRDN_ST) &
+		PD_VOP_PWR_STAT) == 0)) {
+		/*
+		 * VOPL case:
+		 * CRU_CLKGATE10_CON(bit10): ACLK_VOP1_PRE_SRC_EN
+		 * CRU_CLKGATE10_CON(bit11): HCLK_VOP1_PRE_EN
+		 * CRU_CLKGATE10_CON(bit13): DCLK_VOP1_SRC_EN
+		 * CRU_CLKGATE28_CON(bit7): ACLK_VOP1_EN
+		 * CRU_CLKGATE28_CON(bit6): HCLK_VOP1_EN
+		 *
+		 * VOPB case:
+		 * CRU_CLKGATE10_CON(bit8): ACLK_VOP0_PRE_SRC_EN
+		 * CRU_CLKGATE10_CON(bit9): HCLK_VOP0_PRE_EN
+		 * CRU_CLKGATE10_CON(bit12): DCLK_VOP0_SRC_EN
+		 * CRU_CLKGATE28_CON(bit3): ACLK_VOP0_EN
+		 * CRU_CLKGATE28_CON(bit2): HCLK_VOP0_EN
+		 */
+		if (((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE10_CON) &
+		      0x2c00) == 0) &&
+		    ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE28_CON) &
+		      0xc0) == 0)) {
+			if (check_dma_status(VOP_LITE_BASE_ADDR, &clr_dma_flag))
+				return;
+		} else if (((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE10_CON) &
+			     0x1300) == 0) &&
+			   ((mmio_read_32(CRU_BASE_ADDR + CRU_CLKGATE28_CON) &
+			     0x0c) == 0)) {
+			if (check_dma_status(VOP_BIG_BASE_ADDR, &clr_dma_flag))
 				return;
+		} else {
+			/* No VOPs are enabled, so don't wait. */
+			return;
+		}
 
-	/* clean dma finish irq and wait for it */
-	mmio_write_32(vop_adr + VOP_INTR_CLEAR0,
-		      INT_CLR_DMA_FINISH | (INT_CLR_DMA_FINISH << 16));
+		if (stopwatch_expired()) {
+			ret = 1;
+			goto out;
+		}
+	}
 
-	while ((mmio_read_32(vop_adr + VOP_INTR_RAW_STATUS0) &
-		INT_RAW_STATUS_DMA_FINISH) == 0)
-		;
+out:
+	stopwatch_reset();
+	return ret;
 }
 
 static void idle_port(void)
@@ -207,6 +219,7 @@ static void ddr_set_pll(void)
 void handle_dram(void)
 {
 	wait_vop_dma_finish();
+
 	idle_port();
 
 	mmio_write_32(CIC_BASE_ADDR + CIC_CTRL0,