usb: dwc3: debugfs: Dump internal LSP and ep registers

To dump internal LSP and endpoint state debug registers, we must write
to GDBGLSPMUX register. This patch correctly dump LSP and endpoint
states from the debug registers.

If the controller is in device mode, all LSP and endpoint state
registers will be dumped via the debugfs attribute "lsp_dump". In host
mode, the user has to write the LSP number to "lsp_dump" to dump a
specific LSP selection.

Fixes: 80b776340c78 ("usb: dwc3: Dump LSP and BMU debug info")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 141 insertions, 4 deletions

diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index bd3d75b2f8bc..1da012f105d7 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -25,6 +25,8 @@
 #include "io.h"
 #include "debug.h"
 
+#define DWC3_LSP_MUX_UNSELECTED 0xfffff
+
 #define dump_register(nm)				\
 {							\
 	.name	= __stringify(nm),			\
@@ -82,10 +84,6 @@ static const struct debugfs_reg32 dwc3_regs[] = {
 	dump_register(GDBGFIFOSPACE),
 	dump_register(GDBGLTSSM),
 	dump_register(GDBGBMU),
-	dump_register(GDBGLSPMUX),
-	dump_register(GDBGLSP),
-	dump_register(GDBGEPINFO0),
-	dump_register(GDBGEPINFO1),
 	dump_register(GPRTBIMAP_HS0),
 	dump_register(GPRTBIMAP_HS1),
 	dump_register(GPRTBIMAP_FS0),
@@ -279,6 +277,114 @@ static const struct debugfs_reg32 dwc3_regs[] = {
 	dump_register(OSTS),
 };
 
+static void dwc3_host_lsp(struct seq_file *s)
+{
+	struct dwc3		*dwc = s->private;
+	bool			dbc_enabled;
+	u32			sel;
+	u32			reg;
+	u32			val;
+
+	dbc_enabled = !!(dwc->hwparams.hwparams1 & DWC3_GHWPARAMS1_ENDBC);
+
+	sel = dwc->dbg_lsp_select;
+	if (sel == DWC3_LSP_MUX_UNSELECTED) {
+		seq_puts(s, "Write LSP selection to print for host\n");
+		return;
+	}
+
+	reg = DWC3_GDBGLSPMUX_HOSTSELECT(sel);
+
+	dwc3_writel(dwc->regs, DWC3_GDBGLSPMUX, reg);
+	val = dwc3_readl(dwc->regs, DWC3_GDBGLSP);
+	seq_printf(s, "GDBGLSP[%d] = 0x%08x\n", sel, val);
+
+	if (dbc_enabled && sel < 256) {
+		reg |= DWC3_GDBGLSPMUX_ENDBC;
+		dwc3_writel(dwc->regs, DWC3_GDBGLSPMUX, reg);
+		val = dwc3_readl(dwc->regs, DWC3_GDBGLSP);
+		seq_printf(s, "GDBGLSP_DBC[%d] = 0x%08x\n", sel, val);
+	}
+}
+
+static void dwc3_gadget_lsp(struct seq_file *s)
+{
+	struct dwc3		*dwc = s->private;
+	int			i;
+	u32			reg;
+
+	for (i = 0; i < 16; i++) {
+		reg = DWC3_GDBGLSPMUX_DEVSELECT(i);
+		dwc3_writel(dwc->regs, DWC3_GDBGLSPMUX, reg);
+		reg = dwc3_readl(dwc->regs, DWC3_GDBGLSP);
+		seq_printf(s, "GDBGLSP[%d] = 0x%08x\n", i, reg);
+	}
+}
+
+static int dwc3_lsp_show(struct seq_file *s, void *unused)
+{
+	struct dwc3		*dwc = s->private;
+	unsigned int		current_mode;
+	unsigned long		flags;
+	u32			reg;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
+	current_mode = DWC3_GSTS_CURMOD(reg);
+
+	switch (current_mode) {
+	case DWC3_GSTS_CURMOD_HOST:
+		dwc3_host_lsp(s);
+		break;
+	case DWC3_GSTS_CURMOD_DEVICE:
+		dwc3_gadget_lsp(s);
+		break;
+	default:
+		seq_puts(s, "Mode is unknown, no LSP register printed\n");
+		break;
+	}
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
+static int dwc3_lsp_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, dwc3_lsp_show, inode->i_private);
+}
+
+static ssize_t dwc3_lsp_write(struct file *file, const char __user *ubuf,
+			      size_t count, loff_t *ppos)
+{
+	struct seq_file		*s = file->private_data;
+	struct dwc3		*dwc = s->private;
+	unsigned long		flags;
+	char			buf[32] = { 0 };
+	u32			sel;
+	int			ret;
+
+	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	ret = kstrtouint(buf, 0, &sel);
+	if (ret)
+		return ret;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	dwc->dbg_lsp_select = sel;
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return count;
+}
+
+static const struct file_operations dwc3_lsp_fops = {
+	.open			= dwc3_lsp_open,
+	.write			= dwc3_lsp_write,
+	.read			= seq_read,
+	.llseek			= seq_lseek,
+	.release		= single_release,
+};
+
 static int dwc3_mode_show(struct seq_file *s, void *unused)
 {
 	struct dwc3		*dwc = s->private;
@@ -683,6 +789,30 @@ out:
 	return 0;
 }
 
+static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
+{
+	struct dwc3_ep		*dep = s->private;
+	struct dwc3		*dwc = dep->dwc;
+	unsigned long		flags;
+	u64			ep_info;
+	u32			lower_32_bits;
+	u32			upper_32_bits;
+	u32			reg;
+
+	spin_lock_irqsave(&dwc->lock, flags);
+	reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number);
+	dwc3_writel(dwc->regs, DWC3_GDBGLSPMUX, reg);
+
+	lower_32_bits = dwc3_readl(dwc->regs, DWC3_GDBGEPINFO0);
+	upper_32_bits = dwc3_readl(dwc->regs, DWC3_GDBGEPINFO1);
+
+	ep_info = ((u64)upper_32_bits << 32) | lower_32_bits;
+	seq_printf(s, "0x%016llx\n", ep_info);
+	spin_unlock_irqrestore(&dwc->lock, flags);
+
+	return 0;
+}
+
 DEFINE_SHOW_ATTRIBUTE(dwc3_tx_fifo_size);
 DEFINE_SHOW_ATTRIBUTE(dwc3_rx_fifo_size);
 DEFINE_SHOW_ATTRIBUTE(dwc3_tx_request_queue);
@@ -692,6 +822,7 @@ DEFINE_SHOW_ATTRIBUTE(dwc3_descriptor_fetch_queue);
 DEFINE_SHOW_ATTRIBUTE(dwc3_event_queue);
 DEFINE_SHOW_ATTRIBUTE(dwc3_transfer_type);
 DEFINE_SHOW_ATTRIBUTE(dwc3_trb_ring);
+DEFINE_SHOW_ATTRIBUTE(dwc3_ep_info_register);
 
 static const struct dwc3_ep_file_map dwc3_ep_file_map[] = {
 	{ "tx_fifo_size", &dwc3_tx_fifo_size_fops, },
@@ -703,6 +834,7 @@ static const struct dwc3_ep_file_map dwc3_ep_file_map[] = {
 	{ "event_queue", &dwc3_event_queue_fops, },
 	{ "transfer_type", &dwc3_transfer_type_fops, },
 	{ "trb_ring", &dwc3_trb_ring_fops, },
+	{ "GDBGEPINFO", &dwc3_ep_info_register_fops, },
 };
 
 static void dwc3_debugfs_create_endpoint_files(struct dwc3_ep *dep,
@@ -750,6 +882,8 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
 	if (!dwc->regset)
 		return;
 
+	dwc->dbg_lsp_select = DWC3_LSP_MUX_UNSELECTED;
+
 	dwc->regset->regs = dwc3_regs;
 	dwc->regset->nregs = ARRAY_SIZE(dwc3_regs);
 	dwc->regset->base = dwc->regs - DWC3_GLOBALS_REGS_START;
@@ -759,6 +893,9 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
 
 	debugfs_create_regset32("regdump", S_IRUGO, root, dwc->regset);
 
+	debugfs_create_file("lsp_dump", S_IRUGO | S_IWUSR, root, dwc,
+			    &dwc3_lsp_fops);
+
 	if (IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)) {
 		debugfs_create_file("mode", S_IRUGO | S_IWUSR, root, dwc,
 				    &dwc3_mode_fops);