1 files changed, 188 insertions, 41 deletions

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 25950422b085..4fcc3ba93004 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -450,6 +450,40 @@ static int cdns_parity_error_injection(void *data, u64 value)
 DEFINE_DEBUGFS_ATTRIBUTE(cdns_parity_error_fops, NULL,
 			 cdns_parity_error_injection, "%llu\n");
 
+static int cdns_set_pdi_loopback_source(void *data, u64 value)
+{
+	struct sdw_cdns *cdns = data;
+	unsigned int pdi_out_num = cdns->pcm.num_bd + cdns->pcm.num_out;
+
+	if (value > pdi_out_num)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	cdns->pdi_loopback_source = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_source_fops, NULL, cdns_set_pdi_loopback_source, "%llu\n");
+
+static int cdns_set_pdi_loopback_target(void *data, u64 value)
+{
+	struct sdw_cdns *cdns = data;
+	unsigned int pdi_in_num = cdns->pcm.num_bd + cdns->pcm.num_in;
+
+	if (value > pdi_in_num)
+		return -EINVAL;
+
+	/* Userspace changed the hardware state behind the kernel's back */
+	add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+	cdns->pdi_loopback_target = value;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_target_fops, NULL, cdns_set_pdi_loopback_target, "%llu\n");
+
 /**
  * sdw_cdns_debugfs_init() - Cadence debugfs init
  * @cdns: Cadence instance
@@ -464,6 +498,16 @@ void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
 
 	debugfs_create_file("cdns-parity-error-injection", 0200, root, cdns,
 			    &cdns_parity_error_fops);
+
+	cdns->pdi_loopback_source = -1;
+	cdns->pdi_loopback_target = -1;
+
+	debugfs_create_file("cdns-pdi-loopback-source", 0200, root, cdns,
+			    &cdns_pdi_loopback_source_fops);
+
+	debugfs_create_file("cdns-pdi-loopback-target", 0200, root, cdns,
+			    &cdns_pdi_loopback_target_fops);
+
 }
 EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);
 
@@ -822,7 +866,6 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id)
 {
 	struct sdw_cdns *cdns = dev_id;
 	u32 int_status;
-	int ret = IRQ_HANDLED;
 
 	/* Check if the link is up */
 	if (!cdns->link_up)
@@ -900,7 +943,7 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id)
 	}
 
 	cdns_writel(cdns, CDNS_MCP_INTSTAT, int_status);
-	return ret;
+	return IRQ_HANDLED;
 }
 EXPORT_SYMBOL(sdw_cdns_irq);
 
@@ -936,6 +979,49 @@ static void cdns_update_slave_status_work(struct work_struct *work)
 
 }
 
+/* paranoia check to make sure self-cleared bits are indeed cleared */
+void sdw_cdns_check_self_clearing_bits(struct sdw_cdns *cdns, const char *string,
+				       bool initial_delay, int reset_iterations)
+{
+	u32 mcp_control;
+	u32 mcp_config_update;
+	int i;
+
+	if (initial_delay)
+		usleep_range(1000, 1500);
+
+	mcp_control = cdns_readl(cdns, CDNS_MCP_CONTROL);
+
+	/* the following bits should be cleared immediately */
+	if (mcp_control & CDNS_MCP_CONTROL_CMD_RST)
+		dev_err(cdns->dev, "%s failed: MCP_CONTROL_CMD_RST is not cleared\n", string);
+	if (mcp_control & CDNS_MCP_CONTROL_SOFT_RST)
+		dev_err(cdns->dev, "%s failed: MCP_CONTROL_SOFT_RST is not cleared\n", string);
+	if (mcp_control & CDNS_MCP_CONTROL_SW_RST)
+		dev_err(cdns->dev, "%s failed: MCP_CONTROL_SW_RST is not cleared\n", string);
+	if (mcp_control & CDNS_MCP_CONTROL_CLK_STOP_CLR)
+		dev_err(cdns->dev, "%s failed: MCP_CONTROL_CLK_STOP_CLR is not cleared\n", string);
+	mcp_config_update = cdns_readl(cdns, CDNS_MCP_CONFIG_UPDATE);
+	if (mcp_config_update & CDNS_MCP_CONFIG_UPDATE_BIT)
+		dev_err(cdns->dev, "%s failed: MCP_CONFIG_UPDATE_BIT is not cleared\n", string);
+
+	i = 0;
+	while (mcp_control & CDNS_MCP_CONTROL_HW_RST) {
+		if (i == reset_iterations) {
+			dev_err(cdns->dev, "%s failed: MCP_CONTROL_HW_RST is not cleared\n", string);
+			break;
+		}
+
+		dev_dbg(cdns->dev, "%s: MCP_CONTROL_HW_RST is not cleared at iteration %d\n", string, i);
+		i++;
+
+		usleep_range(1000, 1500);
+		mcp_control = cdns_readl(cdns, CDNS_MCP_CONTROL);
+	}
+
+}
+EXPORT_SYMBOL(sdw_cdns_check_self_clearing_bits);
+
 /*
  * init routines
  */
@@ -946,10 +1032,7 @@ static void cdns_update_slave_status_work(struct work_struct *work)
  */
 int sdw_cdns_exit_reset(struct sdw_cdns *cdns)
 {
-	/* program maximum length reset to be safe */
-	cdns_updatel(cdns, CDNS_MCP_CONTROL,
-		     CDNS_MCP_CONTROL_RST_DELAY,
-		     CDNS_MCP_CONTROL_RST_DELAY);
+	/* keep reset delay unchanged to 4096 cycles */
 
 	/* use hardware generated reset */
 	cdns_updatel(cdns, CDNS_MCP_CONTROL,
@@ -1213,6 +1296,8 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
 
 	cdns_init_clock_ctrl(cdns);
 
+	sdw_cdns_check_self_clearing_bits(cdns, __func__, false, 0);
+
 	/* reset msg_count to default value of FIFOLEVEL */
 	cdns->msg_count = cdns_readl(cdns, CDNS_MCP_FIFOLEVEL);
 
@@ -1286,20 +1371,37 @@ static int cdns_port_params(struct sdw_bus *bus,
 			    struct sdw_port_params *p_params, unsigned int bank)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
-	int dpn_config = 0, dpn_config_off;
+	int dpn_config_off_source;
+	int dpn_config_off_target;
+	int target_num = p_params->num;
+	int source_num = p_params->num;
+	bool override = false;
+	int dpn_config;
+
+	if (target_num == cdns->pdi_loopback_target &&
+	    cdns->pdi_loopback_source != -1) {
+		source_num = cdns->pdi_loopback_source;
+		override = true;
+	}
 
-	if (bank)
-		dpn_config_off = CDNS_DPN_B1_CONFIG(p_params->num);
-	else
-		dpn_config_off = CDNS_DPN_B0_CONFIG(p_params->num);
+	if (bank) {
+		dpn_config_off_source = CDNS_DPN_B1_CONFIG(source_num);
+		dpn_config_off_target = CDNS_DPN_B1_CONFIG(target_num);
+	} else {
+		dpn_config_off_source = CDNS_DPN_B0_CONFIG(source_num);
+		dpn_config_off_target = CDNS_DPN_B0_CONFIG(target_num);
+	}
 
-	dpn_config = cdns_readl(cdns, dpn_config_off);
+	dpn_config = cdns_readl(cdns, dpn_config_off_source);
 
-	u32p_replace_bits(&dpn_config, (p_params->bps - 1), CDNS_DPN_CONFIG_WL);
-	u32p_replace_bits(&dpn_config, p_params->flow_mode, CDNS_DPN_CONFIG_PORT_FLOW);
-	u32p_replace_bits(&dpn_config, p_params->data_mode, CDNS_DPN_CONFIG_PORT_DAT);
+	/* use port params if there is no loopback, otherwise use source as is */
+	if (!override) {
+		u32p_replace_bits(&dpn_config, p_params->bps - 1, CDNS_DPN_CONFIG_WL);
+		u32p_replace_bits(&dpn_config, p_params->flow_mode, CDNS_DPN_CONFIG_PORT_FLOW);
+		u32p_replace_bits(&dpn_config, p_params->data_mode, CDNS_DPN_CONFIG_PORT_DAT);
+	}
 
-	cdns_writel(cdns, dpn_config_off, dpn_config);
+	cdns_writel(cdns, dpn_config_off_target, dpn_config);
 
 	return 0;
 }
@@ -1309,11 +1411,27 @@ static int cdns_transport_params(struct sdw_bus *bus,
 				 enum sdw_reg_bank bank)
 {
 	struct sdw_cdns *cdns = bus_to_cdns(bus);
-	int dpn_offsetctrl = 0, dpn_offsetctrl_off;
-	int dpn_config = 0, dpn_config_off;
-	int dpn_hctrl = 0, dpn_hctrl_off;
-	int num = t_params->port_num;
-	int dpn_samplectrl_off;
+	int dpn_config;
+	int dpn_config_off_source;
+	int dpn_config_off_target;
+	int dpn_hctrl;
+	int dpn_hctrl_off_source;
+	int dpn_hctrl_off_target;
+	int dpn_offsetctrl;
+	int dpn_offsetctrl_off_source;
+	int dpn_offsetctrl_off_target;
+	int dpn_samplectrl;
+	int dpn_samplectrl_off_source;
+	int dpn_samplectrl_off_target;
+	int source_num = t_params->port_num;
+	int target_num = t_params->port_num;
+	bool override = false;
+
+	if (target_num == cdns->pdi_loopback_target &&
+	    cdns->pdi_loopback_source != -1) {
+		source_num = cdns->pdi_loopback_source;
+		override = true;
+	}
 
 	/*
 	 * Note: Only full data port is supported on the Master side for
@@ -1321,32 +1439,59 @@ static int cdns_transport_params(struct sdw_bus *bus,
 	 */
 
 	if (bank) {
-		dpn_config_off = CDNS_DPN_B1_CONFIG(num);
-		dpn_samplectrl_off = CDNS_DPN_B1_SAMPLE_CTRL(num);
-		dpn_hctrl_off = CDNS_DPN_B1_HCTRL(num);
-		dpn_offsetctrl_off = CDNS_DPN_B1_OFFSET_CTRL(num);
+		dpn_config_off_source = CDNS_DPN_B1_CONFIG(source_num);
+		dpn_hctrl_off_source = CDNS_DPN_B1_HCTRL(source_num);
+		dpn_offsetctrl_off_source = CDNS_DPN_B1_OFFSET_CTRL(source_num);
+		dpn_samplectrl_off_source = CDNS_DPN_B1_SAMPLE_CTRL(source_num);
+
+		dpn_config_off_target = CDNS_DPN_B1_CONFIG(target_num);
+		dpn_hctrl_off_target = CDNS_DPN_B1_HCTRL(target_num);
+		dpn_offsetctrl_off_target = CDNS_DPN_B1_OFFSET_CTRL(target_num);
+		dpn_samplectrl_off_target = CDNS_DPN_B1_SAMPLE_CTRL(target_num);
+
 	} else {
-		dpn_config_off = CDNS_DPN_B0_CONFIG(num);
-		dpn_samplectrl_off = CDNS_DPN_B0_SAMPLE_CTRL(num);
-		dpn_hctrl_off = CDNS_DPN_B0_HCTRL(num);
-		dpn_offsetctrl_off = CDNS_DPN_B0_OFFSET_CTRL(num);
+		dpn_config_off_source = CDNS_DPN_B0_CONFIG(source_num);
+		dpn_hctrl_off_source = CDNS_DPN_B0_HCTRL(source_num);
+		dpn_offsetctrl_off_source = CDNS_DPN_B0_OFFSET_CTRL(source_num);
+		dpn_samplectrl_off_source = CDNS_DPN_B0_SAMPLE_CTRL(source_num);
+
+		dpn_config_off_target = CDNS_DPN_B0_CONFIG(target_num);
+		dpn_hctrl_off_target = CDNS_DPN_B0_HCTRL(target_num);
+		dpn_offsetctrl_off_target = CDNS_DPN_B0_OFFSET_CTRL(target_num);
+		dpn_samplectrl_off_target = CDNS_DPN_B0_SAMPLE_CTRL(target_num);
 	}
 
-	dpn_config = cdns_readl(cdns, dpn_config_off);
-	u32p_replace_bits(&dpn_config, t_params->blk_grp_ctrl, CDNS_DPN_CONFIG_BGC);
-	u32p_replace_bits(&dpn_config, t_params->blk_pkg_mode, CDNS_DPN_CONFIG_BPM);
-	cdns_writel(cdns, dpn_config_off, dpn_config);
+	dpn_config = cdns_readl(cdns, dpn_config_off_source);
+	if (!override) {
+		u32p_replace_bits(&dpn_config, t_params->blk_grp_ctrl, CDNS_DPN_CONFIG_BGC);
+		u32p_replace_bits(&dpn_config, t_params->blk_pkg_mode, CDNS_DPN_CONFIG_BPM);
+	}
+	cdns_writel(cdns, dpn_config_off_target, dpn_config);
 
-	u32p_replace_bits(&dpn_offsetctrl, t_params->offset1, CDNS_DPN_OFFSET_CTRL_1);
-	u32p_replace_bits(&dpn_offsetctrl, t_params->offset2, CDNS_DPN_OFFSET_CTRL_2);
-	cdns_writel(cdns, dpn_offsetctrl_off,  dpn_offsetctrl);
+	if (!override) {
+		dpn_offsetctrl = 0;
+		u32p_replace_bits(&dpn_offsetctrl, t_params->offset1, CDNS_DPN_OFFSET_CTRL_1);
+		u32p_replace_bits(&dpn_offsetctrl, t_params->offset2, CDNS_DPN_OFFSET_CTRL_2);
+	} else {
+		dpn_offsetctrl = cdns_readl(cdns, dpn_offsetctrl_off_source);
+	}
+	cdns_writel(cdns, dpn_offsetctrl_off_target,  dpn_offsetctrl);
 
-	u32p_replace_bits(&dpn_hctrl, t_params->hstart, CDNS_DPN_HCTRL_HSTART);
-	u32p_replace_bits(&dpn_hctrl, t_params->hstop, CDNS_DPN_HCTRL_HSTOP);
-	u32p_replace_bits(&dpn_hctrl, t_params->lane_ctrl, CDNS_DPN_HCTRL_LCTRL);
+	if (!override) {
+		dpn_hctrl = 0;
+		u32p_replace_bits(&dpn_hctrl, t_params->hstart, CDNS_DPN_HCTRL_HSTART);
+		u32p_replace_bits(&dpn_hctrl, t_params->hstop, CDNS_DPN_HCTRL_HSTOP);
+		u32p_replace_bits(&dpn_hctrl, t_params->lane_ctrl, CDNS_DPN_HCTRL_LCTRL);
+	} else {
+		dpn_hctrl = cdns_readl(cdns, dpn_hctrl_off_source);
+	}
+	cdns_writel(cdns, dpn_hctrl_off_target, dpn_hctrl);
 
-	cdns_writel(cdns, dpn_hctrl_off, dpn_hctrl);
-	cdns_writel(cdns, dpn_samplectrl_off, (t_params->sample_interval - 1));
+	if (!override)
+		dpn_samplectrl = t_params->sample_interval - 1;
+	else
+		dpn_samplectrl = cdns_readl(cdns, dpn_samplectrl_off_source);
+	cdns_writel(cdns, dpn_samplectrl_off_target, dpn_samplectrl);
 
 	return 0;
 }
@@ -1397,6 +1542,8 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake)
 	struct sdw_slave *slave;
 	int ret;
 
+	sdw_cdns_check_self_clearing_bits(cdns, __func__, false, 0);
+
 	/* Check suspend status */
 	if (sdw_cdns_is_clock_stop(cdns)) {
 		dev_dbg(cdns->dev, "Clock is already stopped\n");