From e229197566f3f292c466c3c3fbbbacbcfc8d8343 Mon Sep 17 00:00:00 2001
From: Laxminath Kasam <lkasam@codeaurora.org>
Date: Fri, 8 Nov 2019 14:51:59 +0530
Subject: [PATCH] soc: soundwire: Handle command response sequence

In soundwire version 1.6 as AHB HCLK and MCLK
are decoupled, need to wait for clock stop
entry and exit scenarios to execute before
any further transactions. Keep monitor on
COMP status accordingly.

Change-Id: I03204526d7dd634a79193b55c6744edca8664d93
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>
---
 soc/swr-mstr-ctrl.c  | 33 +++++++++++++++++++++++++++++++++
 soc/swrm_registers.h |  1 +
 2 files changed, 34 insertions(+)

diff --git a/soc/swr-mstr-ctrl.c b/soc/swr-mstr-ctrl.c
index 008801fae779..c90e6b491b90 100644
--- a/soc/swr-mstr-ctrl.c
+++ b/soc/swr-mstr-ctrl.c
@@ -44,6 +44,7 @@
 #define ERR_AUTO_SUSPEND_TIMER_VAL 0x1
 
 #define SWRM_INTERRUPT_STATUS_MASK 0x1FDFD
+#define SWRM_LINK_STATUS_RETRY_CNT 0x5
 
 #define SWRM_ROW_48    48
 #define SWRM_ROW_50    50
@@ -494,6 +495,31 @@ static int swr_master_bulk_write(struct swr_mstr_ctrl *swrm, u32 *reg_addr,
 	return 0;
 }
 
+static bool swrm_check_link_status(struct swr_mstr_ctrl *swrm, bool active)
+{
+	int retry = SWRM_LINK_STATUS_RETRY_CNT;
+	int ret = false;
+	int status = active ? 0x1 : 0x0;
+
+	if ((swrm->version <= SWRM_VERSION_1_5_1))
+		return true;
+
+	do {
+		if (swr_master_read(swrm, SWRM_COMP_STATUS) & status) {
+			ret = true;
+			break;
+		}
+		retry--;
+		usleep_range(500, 510);
+	} while (retry);
+
+	if (retry == 0)
+		dev_err(swrm->dev, "%s: link status not %s\n", __func__,
+			active ? "connected" : "disconnected");
+
+	return ret;
+}
+
 static bool swrm_is_port_en(struct swr_master *mstr)
 {
 	return !!(mstr->num_port);
@@ -1795,6 +1821,7 @@ handle_irq:
 		case SWRM_INTERRUPT_STATUS_AUTO_ENUM_TABLE_IS_FULL_V2:
 			break;
 		case SWRM_INTERRUPT_STATUS_BUS_RESET_FINISHED_V2:
+			swrm_check_link_status(swrm, 0x1);
 			break;
 		case SWRM_INTERRUPT_STATUS_CLK_STOP_FINISHED_V2:
 			break;
@@ -2615,6 +2642,8 @@ static int swrm_runtime_resume(struct device *dev)
 			swrm_master_init(swrm);
 			/* wait for hw enumeration to complete */
 			usleep_range(100, 105);
+			if (!swrm_check_link_status(swrm, 0x1))
+				goto exit;
 			swrm_cmd_fifo_wr_cmd(swrm, 0x4, 0xF, 0x0,
 						SWRS_SCP_INT_STATUS_MASK_1);
 			if (swrm->state == SWR_MSTR_SSR) {
@@ -2626,6 +2655,8 @@ static int swrm_runtime_resume(struct device *dev)
 			/*wake up from clock stop*/
 			swr_master_write(swrm, SWRM_MCP_BUS_CTRL_ADDR, 0x2);
 			usleep_range(100, 105);
+			if (!swrm_check_link_status(swrm, 0x1))
+				goto exit;
 		}
 		swrm->state = SWR_MSTR_UP;
 	}
@@ -2726,6 +2757,8 @@ static int swrm_runtime_suspend(struct device *dev)
 					SWR_WAKE_IRQ_REGISTER, (void *)swrm);
 				swrm->ipc_wakeup_triggered = false;
 			}
+			if (!swrm_check_link_status(swrm, 0x0))
+				goto exit;
 		}
 
 	}
diff --git a/soc/swrm_registers.h b/soc/swrm_registers.h
index 6f2544b17744..63fe4ca744c4 100644
--- a/soc/swrm_registers.h
+++ b/soc/swrm_registers.h
@@ -17,6 +17,7 @@
 #define SWRM_COMP_CFG_ENABLE_SHFT			0x0
 
 #define SWRM_COMP_SW_RESET		(SWRM_BASE_ADDRESS+0x00000008)
+#define SWRM_COMP_STATUS		(SWRM_BASE_ADDRESS+0x00000014)
 
 #define SWRM_COMP_PARAMS		(SWRM_BASE_ADDRESS+0x100)
 #define SWRM_COMP_PARAMS_DOUT_PORTS_MASK	0x0000001F