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Commit d011411d authored by Feng Tang's avatar Feng Tang Committed by Greg Kroah-Hartman
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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: default avatarFeng Tang <feng.tang@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d3bda529

drivers/tty/serial/pch_uart.c

+84 −0
Original line number Diff line number Diff line
@@ -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);