serial: pch_uart: add debugfs hook for register dump
This driver will be use as interfaces for multiple kinds of
devices like Bluetooth/GPS etc, this debug hook will make driver
debugging much easier.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 17ae657..6d9ca293 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -29,6 +29,7 @@
#include <linux/nmi.h>
#include <linux/delay.h>
+#include <linux/debugfs.h>
#include <linux/dmaengine.h>
#include <linux/pch_dma.h>
@@ -144,6 +145,8 @@
#define PCH_UART_DLL 0x00
#define PCH_UART_DLM 0x01
+#define PCH_UART_BRCSR 0x0E
+
#define PCH_UART_IID_RLS (PCH_UART_IIR_REI)
#define PCH_UART_IID_RDR (PCH_UART_IIR_RRI)
#define PCH_UART_IID_RDR_TO (PCH_UART_IIR_RRI | PCH_UART_IIR_TOI)
@@ -243,6 +246,8 @@
int tx_dma_use;
void *rx_buf_virt;
dma_addr_t rx_buf_dma;
+
+ struct dentry *debugfs;
};
/**
@@ -292,6 +297,73 @@
static const int trigger_level_16[4] = { 1, 4, 8, 14 };
static const int trigger_level_1[4] = { 1, 1, 1, 1 };
+#ifdef CONFIG_DEBUG_FS
+
+#define PCH_REGS_BUFSIZE 1024
+static int pch_show_regs_open(struct inode *inode, struct file *file)
+{
+ file->private_data = inode->i_private;
+ return 0;
+}
+
+static ssize_t port_show_regs(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct eg20t_port *priv = file->private_data;
+ char *buf;
+ u32 len = 0;
+ ssize_t ret;
+ unsigned char lcr;
+
+ buf = kzalloc(PCH_REGS_BUFSIZE, GFP_KERNEL);
+ if (!buf)
+ return 0;
+
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "PCH EG20T port[%d] regs:\n", priv->port.line);
+
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "=================================\n");
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "IER: \t0x%02x\n", ioread8(priv->membase + UART_IER));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "IIR: \t0x%02x\n", ioread8(priv->membase + UART_IIR));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "LCR: \t0x%02x\n", ioread8(priv->membase + UART_LCR));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "MCR: \t0x%02x\n", ioread8(priv->membase + UART_MCR));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "LSR: \t0x%02x\n", ioread8(priv->membase + UART_LSR));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "MSR: \t0x%02x\n", ioread8(priv->membase + UART_MSR));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "BRCSR: \t0x%02x\n",
+ ioread8(priv->membase + PCH_UART_BRCSR));
+
+ lcr = ioread8(priv->membase + UART_LCR);
+ iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "DLL: \t0x%02x\n", ioread8(priv->membase + UART_DLL));
+ len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+ "DLM: \t0x%02x\n", ioread8(priv->membase + UART_DLM));
+ iowrite8(lcr, priv->membase + UART_LCR);
+
+ if (len > PCH_REGS_BUFSIZE)
+ len = PCH_REGS_BUFSIZE;
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations port_regs_ops = {
+ .owner = THIS_MODULE,
+ .open = pch_show_regs_open,
+ .read = port_show_regs,
+ .llseek = default_llseek,
+};
+#endif /* CONFIG_DEBUG_FS */
+
static void pch_uart_hal_request(struct pci_dev *pdev, int fifosize,
int base_baud)
{
@@ -1554,6 +1626,7 @@
int port_type;
struct pch_uart_driver_data *board;
const char *board_name;
+ char name[32]; /* for debugfs file name */
board = &drv_dat[id->driver_data];
port_type = board->port_type;
@@ -1623,6 +1696,12 @@
if (ret < 0)
goto init_port_hal_free;
+#ifdef CONFIG_DEBUG_FS
+ snprintf(name, sizeof(name), "uart%d_regs", board->line_no);
+ priv->debugfs = debugfs_create_file(name, S_IFREG | S_IRUGO,
+ NULL, priv, &port_regs_ops);
+#endif
+
return priv;
init_port_hal_free:
@@ -1639,6 +1718,11 @@
static void pch_uart_exit_port(struct eg20t_port *priv)
{
+
+#ifdef CONFIG_DEBUG_FS
+ if (priv->debugfs)
+ debugfs_remove(priv->debugfs);
+#endif
uart_remove_one_port(&pch_uart_driver, &priv->port);
pci_set_drvdata(priv->pdev, NULL);
free_page((unsigned long)priv->rxbuf.buf);