[TEST] Soundwire/multi link support

drivers/soundwire/cadence_master.c

@@ -184,7 +184,6 @@ MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask");
 #define CDNS_PDI_CONFIG_PORT			GENMASK(4, 0)
 
 /* Driver defaults */
-#define CDNS_DEFAULT_SSP_INTERVAL		0x18
 #define CDNS_TX_TIMEOUT				2000
 
 #define CDNS_SCP_RX_FIFOLEVEL			0x2
@@ -212,26 +211,6 @@ static inline void cdns_updatel(struct sdw_cdns *cdns,
 	cdns_writel(cdns, offset, tmp);
 }
 
-static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
-{
-	int timeout = 10;
-	u32 reg_read;
-
-	writel(value, cdns->registers + offset);
-
-	/* Wait for bit to be self cleared */
-	do {
-		reg_read = readl(cdns->registers + offset);
-		if ((reg_read & value) == 0)
-			return 0;
-
-		timeout--;
-		usleep_range(50, 100);
-	} while (timeout != 0);
-
-	return -EAGAIN;
-}
-
 static int cdns_set_wait(struct sdw_cdns *cdns, int offset, u32 mask, u32 value)
 {
 	int timeout = 10;
@@ -250,14 +229,27 @@ static int cdns_set_wait(struct sdw_cdns *cdns, int offset, u32 mask, u32 value)
 	return -ETIMEDOUT;
 }
 
+static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
+{
+	writel(value, cdns->registers + offset);
+
+	/* Wait for bit to be self cleared */
+	return cdns_set_wait(cdns, offset, value, 0);
+}
+
 /*
  * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL
  * need to be confirmed with a write to MCP_CONFIG_UPDATE
  */
-static int cdns_update_config(struct sdw_cdns *cdns)
+static int cdns_config_update(struct sdw_cdns *cdns)
 {
 	int ret;
 
+	if (sdw_cdns_is_clock_stop(cdns)) {
+		dev_err(cdns->dev, "Cannot program MCP_CONFIG_UPDATE in ClockStopMode\n");
+		return -EINVAL;
+	}
+
 	ret = cdns_clear_bit(cdns, CDNS_MCP_CONFIG_UPDATE,
 			     CDNS_MCP_CONFIG_UPDATE_BIT);
 	if (ret < 0)
@@ -851,13 +843,14 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns)
 		     CDNS_MCP_CONTROL_HW_RST,
 		     CDNS_MCP_CONTROL_HW_RST);
 
-	/* enable bus operations with clock and data */
-	cdns_updatel(cdns, CDNS_MCP_CONFIG,
-		     CDNS_MCP_CONFIG_OP,
-		     CDNS_MCP_CONFIG_OP_NORMAL);
-
 	/* commit changes */
-	return cdns_update_config(cdns);
+	cdns_updatel(cdns, CDNS_MCP_CONFIG_UPDATE,
+		     CDNS_MCP_CONFIG_UPDATE_BIT,
+		     CDNS_MCP_CONFIG_UPDATE_BIT);
+
+	/* don't wait here */
+	return 0;
+
 }
 EXPORT_SYMBOL(sdw_cdns_exit_reset);
 
@@ -1051,15 +1044,12 @@ static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols)
 	return val;
 }
 
-/**
- * sdw_cdns_init() - Cadence initialization
- * @cdns: Cadence instance
- */
-int sdw_cdns_init(struct sdw_cdns *cdns)
+static void cdns_init_clock_ctrl(struct sdw_cdns *cdns)
 {
 	struct sdw_bus *bus = &cdns->bus;
 	struct sdw_master_prop *prop = &bus->prop;
 	u32 val;
+	u32 ssp_interval;
 	int divider;
 
 	/* Set clock divider */
@@ -1079,8 +1069,20 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
 	cdns_writel(cdns, CDNS_MCP_FRAME_SHAPE_INIT, val);
 
 	/* Set SSP interval to default value */
-	cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, CDNS_DEFAULT_SSP_INTERVAL);
-	cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, CDNS_DEFAULT_SSP_INTERVAL);
+	ssp_interval = prop->default_frame_rate / SDW_CADENCE_GSYNC_HZ;
+	cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, ssp_interval);
+	cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, ssp_interval);
+}
+
+/**
+ * sdw_cdns_init() - Cadence initialization
+ * @cdns: Cadence instance
+ */
+int sdw_cdns_init(struct sdw_cdns *cdns)
+{
+	u32 val;
+
+	cdns_init_clock_ctrl(cdns);
 
 	/* reset msg_count to default value of FIFOLEVEL */
 	cdns->msg_count = cdns_readl(cdns, CDNS_MCP_FIFOLEVEL);
@@ -1096,25 +1098,31 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
 	/* Configure mcp config */
 	val = cdns_readl(cdns, CDNS_MCP_CONFIG);
 
-	/* Set Max cmd retry to 15 */
-	val |= CDNS_MCP_CONFIG_MCMD_RETRY;
+	/* enable bus operations with clock and data */
+	val &= ~CDNS_MCP_CONFIG_OP;
+	val |= CDNS_MCP_CONFIG_OP_NORMAL;
 
-	/* Set frame delay between PREQ and ping frame to 15 frames */
-	val |= 0xF << SDW_REG_SHIFT(CDNS_MCP_CONFIG_MPREQ_DELAY);
+	/* Set cmd mode for Tx and Rx cmds */
+	val &= ~CDNS_MCP_CONFIG_CMD;
+
+	/* Disable sniffer mode */
+	val &= ~CDNS_MCP_CONFIG_SNIFFER;
 
 	/* Disable auto bus release */
 	val &= ~CDNS_MCP_CONFIG_BUS_REL;
 
-	/* Disable sniffer mode */
-	val &= ~CDNS_MCP_CONFIG_SNIFFER;
+	if (cdns->bus.multi_link)
+		/* Set Multi-master mode to take gsync into account */
+		val |= CDNS_MCP_CONFIG_MMASTER;
 
-	/* Set cmd mode for Tx and Rx cmds */
-	val &= ~CDNS_MCP_CONFIG_CMD;
+	/* leave frame delay to hardware default of 0x1F */
+
+	/* leave command retry to hardware default of 0 */
 
 	cdns_writel(cdns, CDNS_MCP_CONFIG, val);
 
-	/* commit changes */
-	return cdns_update_config(cdns);
+	/* changes will be committed later */
+	return 0;
 }
 EXPORT_SYMBOL(sdw_cdns_init);
 
@@ -1326,7 +1334,11 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake)
 			     CDNS_MCP_CONTROL_CMD_ACCEPT, 0);
 
 	/* commit changes */
-	cdns_update_config(cdns);
+	ret = cdns_config_update(cdns);
+	if (ret < 0) {
+		dev_err(cdns->dev, "%s: config_update failed\n", __func__);
+		return ret;
+	}
 
 	/* Prepare slaves for clock stop */
 	ret = sdw_bus_prep_clk_stop(&cdns->bus);
@@ -1391,26 +1403,19 @@ int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset)
 	 */
 	cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, 0);
 
-	if (bus_reset) {
-		/* program maximum length reset to be safe */
-		cdns_updatel(cdns, CDNS_MCP_CONTROL,
-			     CDNS_MCP_CONTROL_RST_DELAY,
-			     CDNS_MCP_CONTROL_RST_DELAY);
+	if (!bus_reset) {
 
-		/* use hardware generated reset */
-		cdns_updatel(cdns, CDNS_MCP_CONTROL,
-			     CDNS_MCP_CONTROL_HW_RST,
-			     CDNS_MCP_CONTROL_HW_RST);
-	}
+		/* enable bus operations with clock and data */
+		cdns_updatel(cdns, CDNS_MCP_CONFIG,
+			     CDNS_MCP_CONFIG_OP,
+			     CDNS_MCP_CONFIG_OP_NORMAL);
 
-	/* enable bus operations with clock and data */
-	cdns_updatel(cdns, CDNS_MCP_CONFIG,
-		     CDNS_MCP_CONFIG_OP,
-		     CDNS_MCP_CONFIG_OP_NORMAL);
-
-	cdns_update_config(cdns);
+		ret = cdns_config_update(cdns);
+		if (ret < 0) {
+			dev_err(cdns->dev, "%s: config_update failed\n", __func__);
+			return ret;
+		}
 
-	if (!bus_reset) {
 		ret = sdw_bus_exit_clk_stop(&cdns->bus);
 		if (ret < 0)
 			dev_err(cdns->dev, "bus failed to exit clock stop %d\n", ret);

drivers/soundwire/cadence_master.h

@@ -5,6 +5,9 @@
 #ifndef __SDW_CADENCE_H
 #define __SDW_CADENCE_H
 
+#define SDW_CADENCE_GSYNC_KHZ		4 /* 4 kHz */
+#define SDW_CADENCE_GSYNC_HZ		(SDW_CADENCE_GSYNC_KHZ * 1000)
+
 /**
  * struct sdw_cdns_pdi: PDI (Physical Data Interface) instance
  *