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>
This commit is contained in:
Feng Tang 2012-02-06 17:24:43 +08:00 committed by Greg Kroah-Hartman
parent d3bda5298a
commit d011411ddb

View file

@ -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 @@ enum {
#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 @@ struct eg20t_port {
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_64[4] = { 1, 16, 32, 56 };
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 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
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 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
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 @@ init_port_alloc_err:
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);