Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1918 insertions, 0 deletions

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
new file mode 100644
index 000000000..abff1c647
--- /dev/null
+++ b/drivers/tty/serial/pch_uart.c
@@ -0,0 +1,1918 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *Copyright (C) 2011 LAPIS Semiconductor Co., Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/serial.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/console.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/dmi.h>
+#include <linux/nmi.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+
+#include <linux/debugfs.h>
+#include <linux/dmaengine.h>
+#include <linux/pch_dma.h>
+
+enum {
+	PCH_UART_HANDLED_RX_INT_SHIFT,
+	PCH_UART_HANDLED_TX_INT_SHIFT,
+	PCH_UART_HANDLED_RX_ERR_INT_SHIFT,
+	PCH_UART_HANDLED_RX_TRG_INT_SHIFT,
+	PCH_UART_HANDLED_MS_INT_SHIFT,
+	PCH_UART_HANDLED_LS_INT_SHIFT,
+};
+
+#define PCH_UART_DRIVER_DEVICE "ttyPCH"
+
+/* Set the max number of UART port
+ * Intel EG20T PCH: 4 port
+ * LAPIS Semiconductor ML7213 IOH: 3 port
+ * LAPIS Semiconductor ML7223 IOH: 2 port
+*/
+#define PCH_UART_NR	4
+
+#define PCH_UART_HANDLED_RX_INT	(1<<((PCH_UART_HANDLED_RX_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_TX_INT	(1<<((PCH_UART_HANDLED_TX_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_RX_ERR_INT	(1<<((\
+					PCH_UART_HANDLED_RX_ERR_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_RX_TRG_INT	(1<<((\
+					PCH_UART_HANDLED_RX_TRG_INT_SHIFT)<<1))
+#define PCH_UART_HANDLED_MS_INT	(1<<((PCH_UART_HANDLED_MS_INT_SHIFT)<<1))
+
+#define PCH_UART_HANDLED_LS_INT	(1<<((PCH_UART_HANDLED_LS_INT_SHIFT)<<1))
+
+#define PCH_UART_RBR		0x00
+#define PCH_UART_THR		0x00
+
+#define PCH_UART_IER_MASK	(PCH_UART_IER_ERBFI|PCH_UART_IER_ETBEI|\
+				PCH_UART_IER_ELSI|PCH_UART_IER_EDSSI)
+#define PCH_UART_IER_ERBFI	0x00000001
+#define PCH_UART_IER_ETBEI	0x00000002
+#define PCH_UART_IER_ELSI	0x00000004
+#define PCH_UART_IER_EDSSI	0x00000008
+
+#define PCH_UART_IIR_IP			0x00000001
+#define PCH_UART_IIR_IID		0x00000006
+#define PCH_UART_IIR_MSI		0x00000000
+#define PCH_UART_IIR_TRI		0x00000002
+#define PCH_UART_IIR_RRI		0x00000004
+#define PCH_UART_IIR_REI		0x00000006
+#define PCH_UART_IIR_TOI		0x00000008
+#define PCH_UART_IIR_FIFO256		0x00000020
+#define PCH_UART_IIR_FIFO64		PCH_UART_IIR_FIFO256
+#define PCH_UART_IIR_FE			0x000000C0
+
+#define PCH_UART_FCR_FIFOE		0x00000001
+#define PCH_UART_FCR_RFR		0x00000002
+#define PCH_UART_FCR_TFR		0x00000004
+#define PCH_UART_FCR_DMS		0x00000008
+#define PCH_UART_FCR_FIFO256		0x00000020
+#define PCH_UART_FCR_RFTL		0x000000C0
+
+#define PCH_UART_FCR_RFTL1		0x00000000
+#define PCH_UART_FCR_RFTL64		0x00000040
+#define PCH_UART_FCR_RFTL128		0x00000080
+#define PCH_UART_FCR_RFTL224		0x000000C0
+#define PCH_UART_FCR_RFTL16		PCH_UART_FCR_RFTL64
+#define PCH_UART_FCR_RFTL32		PCH_UART_FCR_RFTL128
+#define PCH_UART_FCR_RFTL56		PCH_UART_FCR_RFTL224
+#define PCH_UART_FCR_RFTL4		PCH_UART_FCR_RFTL64
+#define PCH_UART_FCR_RFTL8		PCH_UART_FCR_RFTL128
+#define PCH_UART_FCR_RFTL14		PCH_UART_FCR_RFTL224
+#define PCH_UART_FCR_RFTL_SHIFT		6
+
+#define PCH_UART_LCR_WLS	0x00000003
+#define PCH_UART_LCR_STB	0x00000004
+#define PCH_UART_LCR_PEN	0x00000008
+#define PCH_UART_LCR_EPS	0x00000010
+#define PCH_UART_LCR_SP		0x00000020
+#define PCH_UART_LCR_SB		0x00000040
+#define PCH_UART_LCR_DLAB	0x00000080
+#define PCH_UART_LCR_NP		0x00000000
+#define PCH_UART_LCR_OP		PCH_UART_LCR_PEN
+#define PCH_UART_LCR_EP		(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS)
+#define PCH_UART_LCR_1P		(PCH_UART_LCR_PEN | PCH_UART_LCR_SP)
+#define PCH_UART_LCR_0P		(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS |\
+				PCH_UART_LCR_SP)
+
+#define PCH_UART_LCR_5BIT	0x00000000
+#define PCH_UART_LCR_6BIT	0x00000001
+#define PCH_UART_LCR_7BIT	0x00000002
+#define PCH_UART_LCR_8BIT	0x00000003
+
+#define PCH_UART_MCR_DTR	0x00000001
+#define PCH_UART_MCR_RTS	0x00000002
+#define PCH_UART_MCR_OUT	0x0000000C
+#define PCH_UART_MCR_LOOP	0x00000010
+#define PCH_UART_MCR_AFE	0x00000020
+
+#define PCH_UART_LSR_DR		0x00000001
+#define PCH_UART_LSR_ERR	(1<<7)
+
+#define PCH_UART_MSR_DCTS	0x00000001
+#define PCH_UART_MSR_DDSR	0x00000002
+#define PCH_UART_MSR_TERI	0x00000004
+#define PCH_UART_MSR_DDCD	0x00000008
+#define PCH_UART_MSR_CTS	0x00000010
+#define PCH_UART_MSR_DSR	0x00000020
+#define PCH_UART_MSR_RI		0x00000040
+#define PCH_UART_MSR_DCD	0x00000080
+#define PCH_UART_MSR_DELTA	(PCH_UART_MSR_DCTS | PCH_UART_MSR_DDSR |\
+				PCH_UART_MSR_TERI | PCH_UART_MSR_DDCD)
+
+#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)
+#define PCH_UART_IID_THRE	(PCH_UART_IIR_TRI)
+#define PCH_UART_IID_MS		(PCH_UART_IIR_MSI)
+
+#define PCH_UART_HAL_PARITY_NONE	(PCH_UART_LCR_NP)
+#define PCH_UART_HAL_PARITY_ODD		(PCH_UART_LCR_OP)
+#define PCH_UART_HAL_PARITY_EVEN	(PCH_UART_LCR_EP)
+#define PCH_UART_HAL_PARITY_FIX1	(PCH_UART_LCR_1P)
+#define PCH_UART_HAL_PARITY_FIX0	(PCH_UART_LCR_0P)
+#define PCH_UART_HAL_5BIT		(PCH_UART_LCR_5BIT)
+#define PCH_UART_HAL_6BIT		(PCH_UART_LCR_6BIT)
+#define PCH_UART_HAL_7BIT		(PCH_UART_LCR_7BIT)
+#define PCH_UART_HAL_8BIT		(PCH_UART_LCR_8BIT)
+#define PCH_UART_HAL_STB1		0
+#define PCH_UART_HAL_STB2		(PCH_UART_LCR_STB)
+
+#define PCH_UART_HAL_CLR_TX_FIFO	(PCH_UART_FCR_TFR)
+#define PCH_UART_HAL_CLR_RX_FIFO	(PCH_UART_FCR_RFR)
+#define PCH_UART_HAL_CLR_ALL_FIFO	(PCH_UART_HAL_CLR_TX_FIFO | \
+					PCH_UART_HAL_CLR_RX_FIFO)
+
+#define PCH_UART_HAL_DMA_MODE0		0
+#define PCH_UART_HAL_FIFO_DIS		0
+#define PCH_UART_HAL_FIFO16		(PCH_UART_FCR_FIFOE)
+#define PCH_UART_HAL_FIFO256		(PCH_UART_FCR_FIFOE | \
+					PCH_UART_FCR_FIFO256)
+#define PCH_UART_HAL_FIFO64		(PCH_UART_HAL_FIFO256)
+#define PCH_UART_HAL_TRIGGER1		(PCH_UART_FCR_RFTL1)
+#define PCH_UART_HAL_TRIGGER64		(PCH_UART_FCR_RFTL64)
+#define PCH_UART_HAL_TRIGGER128		(PCH_UART_FCR_RFTL128)
+#define PCH_UART_HAL_TRIGGER224		(PCH_UART_FCR_RFTL224)
+#define PCH_UART_HAL_TRIGGER16		(PCH_UART_FCR_RFTL16)
+#define PCH_UART_HAL_TRIGGER32		(PCH_UART_FCR_RFTL32)
+#define PCH_UART_HAL_TRIGGER56		(PCH_UART_FCR_RFTL56)
+#define PCH_UART_HAL_TRIGGER4		(PCH_UART_FCR_RFTL4)
+#define PCH_UART_HAL_TRIGGER8		(PCH_UART_FCR_RFTL8)
+#define PCH_UART_HAL_TRIGGER14		(PCH_UART_FCR_RFTL14)
+#define PCH_UART_HAL_TRIGGER_L		(PCH_UART_FCR_RFTL64)
+#define PCH_UART_HAL_TRIGGER_M		(PCH_UART_FCR_RFTL128)
+#define PCH_UART_HAL_TRIGGER_H		(PCH_UART_FCR_RFTL224)
+
+#define PCH_UART_HAL_RX_INT		(PCH_UART_IER_ERBFI)
+#define PCH_UART_HAL_TX_INT		(PCH_UART_IER_ETBEI)
+#define PCH_UART_HAL_RX_ERR_INT		(PCH_UART_IER_ELSI)
+#define PCH_UART_HAL_MS_INT		(PCH_UART_IER_EDSSI)
+#define PCH_UART_HAL_ALL_INT		(PCH_UART_IER_MASK)
+
+#define PCH_UART_HAL_DTR		(PCH_UART_MCR_DTR)
+#define PCH_UART_HAL_RTS		(PCH_UART_MCR_RTS)
+#define PCH_UART_HAL_OUT		(PCH_UART_MCR_OUT)
+#define PCH_UART_HAL_LOOP		(PCH_UART_MCR_LOOP)
+#define PCH_UART_HAL_AFE		(PCH_UART_MCR_AFE)
+
+#define DEFAULT_UARTCLK   1843200 /*   1.8432 MHz */
+#define CMITC_UARTCLK   192000000 /* 192.0000 MHz */
+#define FRI2_64_UARTCLK  64000000 /*  64.0000 MHz */
+#define FRI2_48_UARTCLK  48000000 /*  48.0000 MHz */
+#define NTC1_UARTCLK     64000000 /*  64.0000 MHz */
+#define MINNOW_UARTCLK   50000000 /*  50.0000 MHz */
+
+struct pch_uart_buffer {
+	unsigned char *buf;
+	int size;
+};
+
+struct eg20t_port {
+	struct uart_port port;
+	int port_type;
+	void __iomem *membase;
+	resource_size_t mapbase;
+	unsigned int iobase;
+	struct pci_dev *pdev;
+	int fifo_size;
+	unsigned int uartclk;
+	int start_tx;
+	int start_rx;
+	int tx_empty;
+	int trigger;
+	int trigger_level;
+	struct pch_uart_buffer rxbuf;
+	unsigned int dmsr;
+	unsigned int fcr;
+	unsigned int mcr;
+	unsigned int use_dma;
+	struct dma_async_tx_descriptor	*desc_tx;
+	struct dma_async_tx_descriptor	*desc_rx;
+	struct pch_dma_slave		param_tx;
+	struct pch_dma_slave		param_rx;
+	struct dma_chan			*chan_tx;
+	struct dma_chan			*chan_rx;
+	struct scatterlist		*sg_tx_p;
+	int				nent;
+	int				orig_nent;
+	struct scatterlist		sg_rx;
+	int				tx_dma_use;
+	void				*rx_buf_virt;
+	dma_addr_t			rx_buf_dma;
+
+#define IRQ_NAME_SIZE 17
+	char				irq_name[IRQ_NAME_SIZE];
+
+	/* protect the eg20t_port private structure and io access to membase */
+	spinlock_t lock;
+};
+
+/**
+ * struct pch_uart_driver_data - private data structure for UART-DMA
+ * @port_type:			The type of UART port
+ * @line_no:			UART port line number (0, 1, 2...)
+ */
+struct pch_uart_driver_data {
+	int port_type;
+	int line_no;
+};
+
+enum pch_uart_num_t {
+	pch_et20t_uart0 = 0,
+	pch_et20t_uart1,
+	pch_et20t_uart2,
+	pch_et20t_uart3,
+	pch_ml7213_uart0,
+	pch_ml7213_uart1,
+	pch_ml7213_uart2,
+	pch_ml7223_uart0,
+	pch_ml7223_uart1,
+	pch_ml7831_uart0,
+	pch_ml7831_uart1,
+};
+
+static struct pch_uart_driver_data drv_dat[] = {
+	[pch_et20t_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_et20t_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_et20t_uart2] = {PORT_PCH_2LINE, 2},
+	[pch_et20t_uart3] = {PORT_PCH_2LINE, 3},
+	[pch_ml7213_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7213_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_ml7213_uart2] = {PORT_PCH_2LINE, 2},
+	[pch_ml7223_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7223_uart1] = {PORT_PCH_2LINE, 1},
+	[pch_ml7831_uart0] = {PORT_PCH_8LINE, 0},
+	[pch_ml7831_uart1] = {PORT_PCH_2LINE, 1},
+};
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+static struct eg20t_port *pch_uart_ports[PCH_UART_NR];
+#endif
+static unsigned int default_baud = 9600;
+static unsigned int user_uartclk = 0;
+static const int trigger_level_256[4] = { 1, 64, 128, 224 };
+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 };
+
+#define PCH_REGS_BUFSIZE	1024
+
+
+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 += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"PCH EG20T port[%d] regs:\n", priv->port.line);
+
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IER: \t0x%02x\n", ioread8(priv->membase + UART_IER));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IIR: \t0x%02x\n", ioread8(priv->membase + UART_IIR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LCR: \t0x%02x\n", ioread8(priv->membase + UART_LCR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MCR: \t0x%02x\n", ioread8(priv->membase + UART_MCR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LSR: \t0x%02x\n", ioread8(priv->membase + UART_LSR));
+	len += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MSR: \t0x%02x\n", ioread8(priv->membase + UART_MSR));
+	len += scnprintf(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 += scnprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"DLL: \t0x%02x\n", ioread8(priv->membase + UART_DLL));
+	len += scnprintf(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		= simple_open,
+	.read		= port_show_regs,
+	.llseek		= default_llseek,
+};
+
+static const struct dmi_system_id pch_uart_dmi_table[] = {
+	{
+		.ident = "CM-iTC",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "CM-iTC"),
+		},
+		(void *)CMITC_UARTCLK,
+	},
+	{
+		.ident = "FRI2",
+		{
+			DMI_MATCH(DMI_BIOS_VERSION, "FRI2"),
+		},
+		(void *)FRI2_64_UARTCLK,
+	},
+	{
+		.ident = "Fish River Island II",
+		{
+			DMI_MATCH(DMI_PRODUCT_NAME, "Fish River Island II"),
+		},
+		(void *)FRI2_48_UARTCLK,
+	},
+	{
+		.ident = "COMe-mTT",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "COMe-mTT"),
+		},
+		(void *)NTC1_UARTCLK,
+	},
+	{
+		.ident = "nanoETXexpress-TT",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-TT"),
+		},
+		(void *)NTC1_UARTCLK,
+	},
+	{
+		.ident = "MinnowBoard",
+		{
+			DMI_MATCH(DMI_BOARD_NAME, "MinnowBoard"),
+		},
+		(void *)MINNOW_UARTCLK,
+	},
+	{ }
+};
+
+/* Return UART clock, checking for board specific clocks. */
+static unsigned int pch_uart_get_uartclk(void)
+{
+	const struct dmi_system_id *d;
+
+	if (user_uartclk)
+		return user_uartclk;
+
+	d = dmi_first_match(pch_uart_dmi_table);
+	if (d)
+		return (unsigned long)d->driver_data;
+
+	return DEFAULT_UARTCLK;
+}
+
+static void pch_uart_hal_enable_interrupt(struct eg20t_port *priv,
+					  unsigned int flag)
+{
+	u8 ier = ioread8(priv->membase + UART_IER);
+	ier |= flag & PCH_UART_IER_MASK;
+	iowrite8(ier, priv->membase + UART_IER);
+}
+
+static void pch_uart_hal_disable_interrupt(struct eg20t_port *priv,
+					   unsigned int flag)
+{
+	u8 ier = ioread8(priv->membase + UART_IER);
+	ier &= ~(flag & PCH_UART_IER_MASK);
+	iowrite8(ier, priv->membase + UART_IER);
+}
+
+static int pch_uart_hal_set_line(struct eg20t_port *priv, unsigned int baud,
+				 unsigned int parity, unsigned int bits,
+				 unsigned int stb)
+{
+	unsigned int dll, dlm, lcr;
+	int div;
+
+	div = DIV_ROUND_CLOSEST(priv->uartclk / 16, baud);
+	if (div < 0 || USHRT_MAX <= div) {
+		dev_err(priv->port.dev, "Invalid Baud(div=0x%x)\n", div);
+		return -EINVAL;
+	}
+
+	dll = (unsigned int)div & 0x00FFU;
+	dlm = ((unsigned int)div >> 8) & 0x00FFU;
+
+	if (parity & ~(PCH_UART_LCR_PEN | PCH_UART_LCR_EPS | PCH_UART_LCR_SP)) {
+		dev_err(priv->port.dev, "Invalid parity(0x%x)\n", parity);
+		return -EINVAL;
+	}
+
+	if (bits & ~PCH_UART_LCR_WLS) {
+		dev_err(priv->port.dev, "Invalid bits(0x%x)\n", bits);
+		return -EINVAL;
+	}
+
+	if (stb & ~PCH_UART_LCR_STB) {
+		dev_err(priv->port.dev, "Invalid STB(0x%x)\n", stb);
+		return -EINVAL;
+	}
+
+	lcr = parity;
+	lcr |= bits;
+	lcr |= stb;
+
+	dev_dbg(priv->port.dev, "%s:baud = %u, div = %04x, lcr = %02x (%lu)\n",
+		 __func__, baud, div, lcr, jiffies);
+	iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
+	iowrite8(dll, priv->membase + PCH_UART_DLL);
+	iowrite8(dlm, priv->membase + PCH_UART_DLM);
+	iowrite8(lcr, priv->membase + UART_LCR);
+
+	return 0;
+}
+
+static int pch_uart_hal_fifo_reset(struct eg20t_port *priv,
+				    unsigned int flag)
+{
+	if (flag & ~(PCH_UART_FCR_TFR | PCH_UART_FCR_RFR)) {
+		dev_err(priv->port.dev, "%s:Invalid flag(0x%x)\n",
+			__func__, flag);
+		return -EINVAL;
+	}
+
+	iowrite8(PCH_UART_FCR_FIFOE | priv->fcr, priv->membase + UART_FCR);
+	iowrite8(PCH_UART_FCR_FIFOE | priv->fcr | flag,
+		 priv->membase + UART_FCR);
+	iowrite8(priv->fcr, priv->membase + UART_FCR);
+
+	return 0;
+}
+
+static int pch_uart_hal_set_fifo(struct eg20t_port *priv,
+				 unsigned int dmamode,
+				 unsigned int fifo_size, unsigned int trigger)
+{
+	u8 fcr;
+
+	if (dmamode & ~PCH_UART_FCR_DMS) {
+		dev_err(priv->port.dev, "%s:Invalid DMA Mode(0x%x)\n",
+			__func__, dmamode);
+		return -EINVAL;
+	}
+
+	if (fifo_size & ~(PCH_UART_FCR_FIFOE | PCH_UART_FCR_FIFO256)) {
+		dev_err(priv->port.dev, "%s:Invalid FIFO SIZE(0x%x)\n",
+			__func__, fifo_size);
+		return -EINVAL;
+	}
+
+	if (trigger & ~PCH_UART_FCR_RFTL) {
+		dev_err(priv->port.dev, "%s:Invalid TRIGGER(0x%x)\n",
+			__func__, trigger);
+		return -EINVAL;
+	}
+
+	switch (priv->fifo_size) {
+	case 256:
+		priv->trigger_level =
+		    trigger_level_256[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	case 64:
+		priv->trigger_level =
+		    trigger_level_64[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	case 16:
+		priv->trigger_level =
+		    trigger_level_16[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	default:
+		priv->trigger_level =
+		    trigger_level_1[trigger >> PCH_UART_FCR_RFTL_SHIFT];
+		break;
+	}
+	fcr =
+	    dmamode | fifo_size | trigger | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR;
+	iowrite8(PCH_UART_FCR_FIFOE, priv->membase + UART_FCR);
+	iowrite8(PCH_UART_FCR_FIFOE | PCH_UART_FCR_RFR | PCH_UART_FCR_TFR,
+		 priv->membase + UART_FCR);
+	iowrite8(fcr, priv->membase + UART_FCR);
+	priv->fcr = fcr;
+
+	return 0;
+}
+
+static u8 pch_uart_hal_get_modem(struct eg20t_port *priv)
+{
+	unsigned int msr = ioread8(priv->membase + UART_MSR);
+	priv->dmsr = msr & PCH_UART_MSR_DELTA;
+	return (u8)msr;
+}
+
+static int pch_uart_hal_read(struct eg20t_port *priv, unsigned char *buf,
+			     int rx_size)
+{
+	int i;
+	u8 rbr, lsr;
+	struct uart_port *port = &priv->port;
+
+	lsr = ioread8(priv->membase + UART_LSR);
+	for (i = 0, lsr = ioread8(priv->membase + UART_LSR);
+	     i < rx_size && lsr & (UART_LSR_DR | UART_LSR_BI);
+	     lsr = ioread8(priv->membase + UART_LSR)) {
+		rbr = ioread8(priv->membase + PCH_UART_RBR);
+
+		if (lsr & UART_LSR_BI) {
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		}
+		if (uart_handle_sysrq_char(port, rbr))
+			continue;
+
+		buf[i++] = rbr;
+	}
+	return i;
+}
+
+static unsigned char pch_uart_hal_get_iid(struct eg20t_port *priv)
+{
+	return ioread8(priv->membase + UART_IIR) &\
+		      (PCH_UART_IIR_IID | PCH_UART_IIR_TOI | PCH_UART_IIR_IP);
+}
+
+static u8 pch_uart_hal_get_line_status(struct eg20t_port *priv)
+{
+	return ioread8(priv->membase + UART_LSR);
+}
+
+static void pch_uart_hal_set_break(struct eg20t_port *priv, int on)
+{
+	unsigned int lcr;
+
+	lcr = ioread8(priv->membase + UART_LCR);
+	if (on)
+		lcr |= PCH_UART_LCR_SB;
+	else
+		lcr &= ~PCH_UART_LCR_SB;
+
+	iowrite8(lcr, priv->membase + UART_LCR);
+}
+
+static int push_rx(struct eg20t_port *priv, const unsigned char *buf,
+		   int size)
+{
+	struct uart_port *port = &priv->port;
+	struct tty_port *tport = &port->state->port;
+
+	tty_insert_flip_string(tport, buf, size);
+	tty_flip_buffer_push(tport);
+
+	return 0;
+}
+
+static int dma_push_rx(struct eg20t_port *priv, int size)
+{
+	int room;
+	struct uart_port *port = &priv->port;
+	struct tty_port *tport = &port->state->port;
+
+	room = tty_buffer_request_room(tport, size);
+
+	if (room < size)
+		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",
+			 size - room);
+	if (!room)
+		return 0;
+
+	tty_insert_flip_string(tport, sg_virt(&priv->sg_rx), size);
+
+	port->icount.rx += room;
+
+	return room;
+}
+
+static void pch_free_dma(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+
+	if (priv->chan_tx) {
+		dma_release_channel(priv->chan_tx);
+		priv->chan_tx = NULL;
+	}
+	if (priv->chan_rx) {
+		dma_release_channel(priv->chan_rx);
+		priv->chan_rx = NULL;
+	}
+
+	if (priv->rx_buf_dma) {
+		dma_free_coherent(port->dev, port->fifosize, priv->rx_buf_virt,
+				  priv->rx_buf_dma);
+		priv->rx_buf_virt = NULL;
+		priv->rx_buf_dma = 0;
+	}
+
+	return;
+}
+
+static bool filter(struct dma_chan *chan, void *slave)
+{
+	struct pch_dma_slave *param = slave;
+
+	if ((chan->chan_id == param->chan_id) && (param->dma_dev ==
+						  chan->device->dev)) {
+		chan->private = param;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static void pch_request_dma(struct uart_port *port)
+{
+	dma_cap_mask_t mask;
+	struct dma_chan *chan;
+	struct pci_dev *dma_dev;
+	struct pch_dma_slave *param;
+	struct eg20t_port *priv =
+				container_of(port, struct eg20t_port, port);
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	/* Get DMA's dev information */
+	dma_dev = pci_get_slot(priv->pdev->bus,
+			PCI_DEVFN(PCI_SLOT(priv->pdev->devfn), 0));
+
+	/* Set Tx DMA */
+	param = &priv->param_tx;
+	param->dma_dev = &dma_dev->dev;
+	param->chan_id = priv->port.line * 2; /* Tx = 0, 2, 4, ... */
+
+	param->tx_reg = port->mapbase + UART_TX;
+	chan = dma_request_channel(mask, filter, param);
+	if (!chan) {
+		dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Tx)\n",
+			__func__);
+		pci_dev_put(dma_dev);
+		return;
+	}
+	priv->chan_tx = chan;
+
+	/* Set Rx DMA */
+	param = &priv->param_rx;
+	param->dma_dev = &dma_dev->dev;
+	param->chan_id = priv->port.line * 2 + 1; /* Rx = Tx + 1 */
+
+	param->rx_reg = port->mapbase + UART_RX;
+	chan = dma_request_channel(mask, filter, param);
+	if (!chan) {
+		dev_err(priv->port.dev, "%s:dma_request_channel FAILS(Rx)\n",
+			__func__);
+		dma_release_channel(priv->chan_tx);
+		priv->chan_tx = NULL;
+		pci_dev_put(dma_dev);
+		return;
+	}
+
+	/* Get Consistent memory for DMA */
+	priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize,
+				    &priv->rx_buf_dma, GFP_KERNEL);
+	priv->chan_rx = chan;
+
+	pci_dev_put(dma_dev);
+}
+
+static void pch_dma_rx_complete(void *arg)
+{
+	struct eg20t_port *priv = arg;
+	struct uart_port *port = &priv->port;
+	int count;
+
+	dma_sync_sg_for_cpu(port->dev, &priv->sg_rx, 1, DMA_FROM_DEVICE);
+	count = dma_push_rx(priv, priv->trigger_level);
+	if (count)
+		tty_flip_buffer_push(&port->state->port);
+	async_tx_ack(priv->desc_rx);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					    PCH_UART_HAL_RX_ERR_INT);
+}
+
+static void pch_dma_tx_complete(void *arg)
+{
+	struct eg20t_port *priv = arg;
+	struct uart_port *port = &priv->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct scatterlist *sg = priv->sg_tx_p;
+	int i;
+
+	for (i = 0; i < priv->nent; i++, sg++) {
+		xmit->tail += sg_dma_len(sg);
+		port->icount.tx += sg_dma_len(sg);
+	}
+	xmit->tail &= UART_XMIT_SIZE - 1;
+	async_tx_ack(priv->desc_tx);
+	dma_unmap_sg(port->dev, priv->sg_tx_p, priv->orig_nent, DMA_TO_DEVICE);
+	priv->tx_dma_use = 0;
+	priv->nent = 0;
+	priv->orig_nent = 0;
+	kfree(priv->sg_tx_p);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
+}
+
+static int handle_rx_to(struct eg20t_port *priv)
+{
+	struct pch_uart_buffer *buf;
+	int rx_size;
+	int ret;
+	if (!priv->start_rx) {
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_RX_INT |
+						     PCH_UART_HAL_RX_ERR_INT);
+		return 0;
+	}
+	buf = &priv->rxbuf;
+	do {
+		rx_size = pch_uart_hal_read(priv, buf->buf, buf->size);
+		ret = push_rx(priv, buf->buf, rx_size);
+		if (ret)
+			return 0;
+	} while (rx_size == buf->size);
+
+	return PCH_UART_HANDLED_RX_INT;
+}
+
+static int handle_rx(struct eg20t_port *priv)
+{
+	return handle_rx_to(priv);
+}
+
+static int dma_handle_rx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct dma_async_tx_descriptor *desc;
+	struct scatterlist *sg;
+
+	priv = container_of(port, struct eg20t_port, port);
+	sg = &priv->sg_rx;
+
+	sg_init_table(&priv->sg_rx, 1); /* Initialize SG table */
+
+	sg_dma_len(sg) = priv->trigger_level;
+
+	sg_set_page(&priv->sg_rx, virt_to_page(priv->rx_buf_virt),
+		     sg_dma_len(sg), offset_in_page(priv->rx_buf_virt));
+
+	sg_dma_address(sg) = priv->rx_buf_dma;
+
+	desc = dmaengine_prep_slave_sg(priv->chan_rx,
+			sg, 1, DMA_DEV_TO_MEM,
+			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+
+	if (!desc)
+		return 0;
+
+	priv->desc_rx = desc;
+	desc->callback = pch_dma_rx_complete;
+	desc->callback_param = priv;
+	desc->tx_submit(desc);
+	dma_async_issue_pending(priv->chan_rx);
+
+	return PCH_UART_HANDLED_RX_INT;
+}
+
+static unsigned int handle_tx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	int fifo_size;
+	int tx_empty;
+
+	if (!priv->start_tx) {
+		dev_info(priv->port.dev, "%s:Tx isn't started. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	fifo_size = max(priv->fifo_size, 1);
+	tx_empty = 1;
+	if (port->x_char) {
+		iowrite8(port->x_char, priv->membase + PCH_UART_THR);
+		port->icount.tx++;
+		port->x_char = 0;
+		tx_empty = 0;
+		fifo_size--;
+	}
+
+	while (!uart_tx_stopped(port) && !uart_circ_empty(xmit) && fifo_size) {
+		iowrite8(xmit->buf[xmit->tail], priv->membase + PCH_UART_THR);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		fifo_size--;
+		tx_empty = 0;
+	}
+
+	priv->tx_empty = tx_empty;
+
+	if (tx_empty) {
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		uart_write_wakeup(port);
+	}
+
+	return PCH_UART_HANDLED_TX_INT;
+}
+
+static unsigned int dma_handle_tx(struct eg20t_port *priv)
+{
+	struct uart_port *port = &priv->port;
+	struct circ_buf *xmit = &port->state->xmit;
+	struct scatterlist *sg;
+	int nent;
+	int fifo_size;
+	struct dma_async_tx_descriptor *desc;
+	int num;
+	int i;
+	int bytes;
+	int size;
+	int rem;
+
+	if (!priv->start_tx) {
+		dev_info(priv->port.dev, "%s:Tx isn't started. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	if (priv->tx_dma_use) {
+		dev_dbg(priv->port.dev, "%s:Tx is not completed. (%lu)\n",
+			__func__, jiffies);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		priv->tx_empty = 1;
+		return 0;
+	}
+
+	fifo_size = max(priv->fifo_size, 1);
+
+	if (port->x_char) {
+		iowrite8(port->x_char, priv->membase + PCH_UART_THR);
+		port->icount.tx++;
+		port->x_char = 0;
+		fifo_size--;
+	}
+
+	bytes = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+	if (!bytes) {
+		dev_dbg(priv->port.dev, "%s 0 bytes return\n", __func__);
+		pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_TX_INT);
+		uart_write_wakeup(port);
+		return 0;
+	}
+
+	if (bytes > fifo_size) {
+		num = bytes / fifo_size + 1;
+		size = fifo_size;
+		rem = bytes % fifo_size;
+	} else {
+		num = 1;
+		size = bytes;
+		rem = bytes;
+	}
+
+	dev_dbg(priv->port.dev, "%s num=%d size=%d rem=%d\n",
+		__func__, num, size, rem);
+
+	priv->tx_dma_use = 1;
+
+	priv->sg_tx_p = kmalloc_array(num, sizeof(struct scatterlist), GFP_ATOMIC);
+	if (!priv->sg_tx_p) {
+		dev_err(priv->port.dev, "%s:kzalloc Failed\n", __func__);
+		return 0;
+	}
+
+	sg_init_table(priv->sg_tx_p, num); /* Initialize SG table */
+	sg = priv->sg_tx_p;
+
+	for (i = 0; i < num; i++, sg++) {
+		if (i == (num - 1))
+			sg_set_page(sg, virt_to_page(xmit->buf),
+				    rem, fifo_size * i);
+		else
+			sg_set_page(sg, virt_to_page(xmit->buf),
+				    size, fifo_size * i);
+	}
+
+	sg = priv->sg_tx_p;
+	nent = dma_map_sg(port->dev, sg, num, DMA_TO_DEVICE);
+	if (!nent) {
+		dev_err(priv->port.dev, "%s:dma_map_sg Failed\n", __func__);
+		return 0;
+	}
+	priv->orig_nent = num;
+	priv->nent = nent;
+
+	for (i = 0; i < nent; i++, sg++) {
+		sg->offset = (xmit->tail & (UART_XMIT_SIZE - 1)) +
+			      fifo_size * i;
+		sg_dma_address(sg) = (sg_dma_address(sg) &
+				    ~(UART_XMIT_SIZE - 1)) + sg->offset;
+		if (i == (nent - 1))
+			sg_dma_len(sg) = rem;
+		else
+			sg_dma_len(sg) = size;
+	}
+
+	desc = dmaengine_prep_slave_sg(priv->chan_tx,
+					priv->sg_tx_p, nent, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	if (!desc) {
+		dev_err(priv->port.dev, "%s:dmaengine_prep_slave_sg Failed\n",
+			__func__);
+		return 0;
+	}
+	dma_sync_sg_for_device(port->dev, priv->sg_tx_p, nent, DMA_TO_DEVICE);
+	priv->desc_tx = desc;
+	desc->callback = pch_dma_tx_complete;
+	desc->callback_param = priv;
+
+	desc->tx_submit(desc);
+
+	dma_async_issue_pending(priv->chan_tx);
+
+	return PCH_UART_HANDLED_TX_INT;
+}
+
+static void pch_uart_err_ir(struct eg20t_port *priv, unsigned int lsr)
+{
+	struct uart_port *port = &priv->port;
+	struct tty_struct *tty = tty_port_tty_get(&port->state->port);
+	char   *error_msg[5] = {};
+	int    i = 0;
+
+	if (lsr & PCH_UART_LSR_ERR)
+		error_msg[i++] = "Error data in FIFO\n";
+
+	if (lsr & UART_LSR_FE) {
+		port->icount.frame++;
+		error_msg[i++] = "  Framing Error\n";
+	}
+
+	if (lsr & UART_LSR_PE) {
+		port->icount.parity++;
+		error_msg[i++] = "  Parity Error\n";
+	}
+
+	if (lsr & UART_LSR_OE) {
+		port->icount.overrun++;
+		error_msg[i++] = "  Overrun Error\n";
+	}
+
+	if (tty == NULL) {
+		for (i = 0; error_msg[i] != NULL; i++)
+			dev_err(&priv->pdev->dev, error_msg[i]);
+	} else {
+		tty_kref_put(tty);
+	}
+}
+
+static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
+{
+	struct eg20t_port *priv = dev_id;
+	unsigned int handled;
+	u8 lsr;
+	int ret = 0;
+	unsigned char iid;
+	unsigned long flags;
+	int next = 1;
+	u8 msr;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	handled = 0;
+	while (next) {
+		iid = pch_uart_hal_get_iid(priv);
+		if (iid & PCH_UART_IIR_IP) /* No Interrupt */
+			break;
+		switch (iid) {
+		case PCH_UART_IID_RLS:	/* Receiver Line Status */
+			lsr = pch_uart_hal_get_line_status(priv);
+			if (lsr & (PCH_UART_LSR_ERR | UART_LSR_FE |
+						UART_LSR_PE | UART_LSR_OE)) {
+				pch_uart_err_ir(priv, lsr);
+				ret = PCH_UART_HANDLED_RX_ERR_INT;
+			} else {
+				ret = PCH_UART_HANDLED_LS_INT;
+			}
+			break;
+		case PCH_UART_IID_RDR:	/* Received Data Ready */
+			if (priv->use_dma) {
+				pch_uart_hal_disable_interrupt(priv,
+						PCH_UART_HAL_RX_INT |
+						PCH_UART_HAL_RX_ERR_INT);
+				ret = dma_handle_rx(priv);
+				if (!ret)
+					pch_uart_hal_enable_interrupt(priv,
+						PCH_UART_HAL_RX_INT |
+						PCH_UART_HAL_RX_ERR_INT);
+			} else {
+				ret = handle_rx(priv);
+			}
+			break;
+		case PCH_UART_IID_RDR_TO:	/* Received Data Ready
+						   (FIFO Timeout) */
+			ret = handle_rx_to(priv);
+			break;
+		case PCH_UART_IID_THRE:	/* Transmitter Holding Register
+						   Empty */
+			if (priv->use_dma)
+				ret = dma_handle_tx(priv);
+			else
+				ret = handle_tx(priv);
+			break;
+		case PCH_UART_IID_MS:	/* Modem Status */
+			msr = pch_uart_hal_get_modem(priv);
+			next = 0; /* MS ir prioirty is the lowest. So, MS ir
+				     means final interrupt */
+			if ((msr & UART_MSR_ANY_DELTA) == 0)
+				break;
+			ret |= PCH_UART_HANDLED_MS_INT;
+			break;
+		default:	/* Never junp to this label */
+			dev_err(priv->port.dev, "%s:iid=%02x (%lu)\n", __func__,
+				iid, jiffies);
+			ret = -1;
+			next = 0;
+			break;
+		}
+		handled |= (unsigned int)ret;
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return IRQ_RETVAL(handled);
+}
+
+/* This function tests whether the transmitter fifo and shifter for the port
+						described by 'port' is empty. */
+static unsigned int pch_uart_tx_empty(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (priv->tx_empty)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+/* Returns the current state of modem control inputs. */
+static unsigned int pch_uart_get_mctrl(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	u8 modem;
+	unsigned int ret = 0;
+
+	priv = container_of(port, struct eg20t_port, port);
+	modem = pch_uart_hal_get_modem(priv);
+
+	if (modem & UART_MSR_DCD)
+		ret |= TIOCM_CAR;
+
+	if (modem & UART_MSR_RI)
+		ret |= TIOCM_RNG;
+
+	if (modem & UART_MSR_DSR)
+		ret |= TIOCM_DSR;
+
+	if (modem & UART_MSR_CTS)
+		ret |= TIOCM_CTS;
+
+	return ret;
+}
+
+static void pch_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	u32 mcr = 0;
+	struct eg20t_port *priv = container_of(port, struct eg20t_port, port);
+
+	if (mctrl & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (mctrl & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (mctrl & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	if (priv->mcr & UART_MCR_AFE)
+		mcr |= UART_MCR_AFE;
+
+	if (mctrl)
+		iowrite8(mcr, priv->membase + UART_MCR);
+}
+
+static void pch_uart_stop_tx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	priv->start_tx = 0;
+	priv->tx_dma_use = 0;
+}
+
+static void pch_uart_start_tx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+
+	if (priv->use_dma) {
+		if (priv->tx_dma_use) {
+			dev_dbg(priv->port.dev, "%s : Tx DMA is NOT empty.\n",
+				__func__);
+			return;
+		}
+	}
+
+	priv->start_tx = 1;
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_TX_INT);
+}
+
+static void pch_uart_stop_rx(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	priv->start_rx = 0;
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					     PCH_UART_HAL_RX_ERR_INT);
+}
+
+/* Enable the modem status interrupts. */
+static void pch_uart_enable_ms(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	priv = container_of(port, struct eg20t_port, port);
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_MS_INT);
+}
+
+/* Control the transmission of a break signal. */
+static void pch_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	struct eg20t_port *priv;
+	unsigned long flags;
+
+	priv = container_of(port, struct eg20t_port, port);
+	spin_lock_irqsave(&priv->lock, flags);
+	pch_uart_hal_set_break(priv, ctl);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+/* Grab any interrupt resources and initialise any low level driver state. */
+static int pch_uart_startup(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+	int fifo_size;
+	int trigger_level;
+
+	priv = container_of(port, struct eg20t_port, port);
+	priv->tx_empty = 1;
+
+	if (port->uartclk)
+		priv->uartclk = port->uartclk;
+	else
+		port->uartclk = priv->uartclk;
+
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+	ret = pch_uart_hal_set_line(priv, default_baud,
+			      PCH_UART_HAL_PARITY_NONE, PCH_UART_HAL_8BIT,
+			      PCH_UART_HAL_STB1);
+	if (ret)
+		return ret;
+
+	switch (priv->fifo_size) {
+	case 256:
+		fifo_size = PCH_UART_HAL_FIFO256;
+		break;
+	case 64:
+		fifo_size = PCH_UART_HAL_FIFO64;
+		break;
+	case 16:
+		fifo_size = PCH_UART_HAL_FIFO16;
+		break;
+	case 1:
+	default:
+		fifo_size = PCH_UART_HAL_FIFO_DIS;
+		break;
+	}
+
+	switch (priv->trigger) {
+	case PCH_UART_HAL_TRIGGER1:
+		trigger_level = 1;
+		break;
+	case PCH_UART_HAL_TRIGGER_L:
+		trigger_level = priv->fifo_size / 4;
+		break;
+	case PCH_UART_HAL_TRIGGER_M:
+		trigger_level = priv->fifo_size / 2;
+		break;
+	case PCH_UART_HAL_TRIGGER_H:
+	default:
+		trigger_level = priv->fifo_size - (priv->fifo_size / 8);
+		break;
+	}
+
+	priv->trigger_level = trigger_level;
+	ret = pch_uart_hal_set_fifo(priv, PCH_UART_HAL_DMA_MODE0,
+				    fifo_size, priv->trigger);
+	if (ret < 0)
+		return ret;
+
+	ret = request_irq(priv->port.irq, pch_uart_interrupt, IRQF_SHARED,
+			priv->irq_name, priv);
+	if (ret < 0)
+		return ret;
+
+	if (priv->use_dma)
+		pch_request_dma(port);
+
+	priv->start_rx = 1;
+	pch_uart_hal_enable_interrupt(priv, PCH_UART_HAL_RX_INT |
+					    PCH_UART_HAL_RX_ERR_INT);
+	uart_update_timeout(port, CS8, default_baud);
+
+	return 0;
+}
+
+static void pch_uart_shutdown(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+
+	priv = container_of(port, struct eg20t_port, port);
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+	pch_uart_hal_fifo_reset(priv, PCH_UART_HAL_CLR_ALL_FIFO);
+	ret = pch_uart_hal_set_fifo(priv, PCH_UART_HAL_DMA_MODE0,
+			      PCH_UART_HAL_FIFO_DIS, PCH_UART_HAL_TRIGGER1);
+	if (ret)
+		dev_err(priv->port.dev,
+			"pch_uart_hal_set_fifo Failed(ret=%d)\n", ret);
+
+	pch_free_dma(port);
+
+	free_irq(priv->port.irq, priv);
+}
+
+/* Change the port parameters, including word length, parity, stop
+ *bits.  Update read_status_mask and ignore_status_mask to indicate
+ *the types of events we are interested in receiving.  */
+static void pch_uart_set_termios(struct uart_port *port,
+				 struct ktermios *termios,
+				 const struct ktermios *old)
+{
+	int rtn;
+	unsigned int baud, parity, bits, stb;
+	struct eg20t_port *priv;
+	unsigned long flags;
+
+	priv = container_of(port, struct eg20t_port, port);
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		bits = PCH_UART_HAL_5BIT;
+		break;
+	case CS6:
+		bits = PCH_UART_HAL_6BIT;
+		break;
+	case CS7:
+		bits = PCH_UART_HAL_7BIT;
+		break;
+	default:		/* CS8 */
+		bits = PCH_UART_HAL_8BIT;
+		break;
+	}
+	if (termios->c_cflag & CSTOPB)
+		stb = PCH_UART_HAL_STB2;
+	else
+		stb = PCH_UART_HAL_STB1;
+
+	if (termios->c_cflag & PARENB) {
+		if (termios->c_cflag & PARODD)
+			parity = PCH_UART_HAL_PARITY_ODD;
+		else
+			parity = PCH_UART_HAL_PARITY_EVEN;
+
+	} else
+		parity = PCH_UART_HAL_PARITY_NONE;
+
+	/* Only UART0 has auto hardware flow function */
+	if ((termios->c_cflag & CRTSCTS) && (priv->fifo_size == 256))
+		priv->mcr |= UART_MCR_AFE;
+	else
+		priv->mcr &= ~UART_MCR_AFE;
+
+	termios->c_cflag &= ~CMSPAR; /* Mark/Space parity is not supported */
+
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	spin_lock(&port->lock);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+	rtn = pch_uart_hal_set_line(priv, baud, parity, bits, stb);
+	if (rtn)
+		goto out;
+
+	pch_uart_set_mctrl(&priv->port, priv->port.mctrl);
+	/* Don't rewrite B0 */
+	if (tty_termios_baud_rate(termios))
+		tty_termios_encode_baud_rate(termios, baud, baud);
+
+out:
+	spin_unlock(&port->lock);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static const char *pch_uart_type(struct uart_port *port)
+{
+	return KBUILD_MODNAME;
+}
+
+static void pch_uart_release_port(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	pci_iounmap(priv->pdev, priv->membase);
+	pci_release_regions(priv->pdev);
+}
+
+static int pch_uart_request_port(struct uart_port *port)
+{
+	struct eg20t_port *priv;
+	int ret;
+	void __iomem *membase;
+
+	priv = container_of(port, struct eg20t_port, port);
+	ret = pci_request_regions(priv->pdev, KBUILD_MODNAME);
+	if (ret < 0)
+		return -EBUSY;
+
+	membase = pci_iomap(priv->pdev, 1, 0);
+	if (!membase) {
+		pci_release_regions(priv->pdev);
+		return -EBUSY;
+	}
+	priv->membase = port->membase = membase;
+
+	return 0;
+}
+
+static void pch_uart_config_port(struct uart_port *port, int type)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (type & UART_CONFIG_TYPE) {
+		port->type = priv->port_type;
+		pch_uart_request_port(port);
+	}
+}
+
+static int pch_uart_verify_port(struct uart_port *port,
+				struct serial_struct *serinfo)
+{
+	struct eg20t_port *priv;
+
+	priv = container_of(port, struct eg20t_port, port);
+	if (serinfo->flags & UPF_LOW_LATENCY) {
+		dev_info(priv->port.dev,
+			"PCH UART : Use PIO Mode (without DMA)\n");
+		priv->use_dma = 0;
+		serinfo->flags &= ~UPF_LOW_LATENCY;
+	} else {
+#ifndef CONFIG_PCH_DMA
+		dev_err(priv->port.dev, "%s : PCH DMA is not Loaded.\n",
+			__func__);
+		return -EOPNOTSUPP;
+#endif
+		if (!priv->use_dma) {
+			pch_request_dma(port);
+			if (priv->chan_rx)
+				priv->use_dma = 1;
+		}
+		dev_info(priv->port.dev, "PCH UART: %s\n",
+				priv->use_dma ?
+				"Use DMA Mode" : "No DMA");
+	}
+
+	return 0;
+}
+
+#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_PCH_UART_CONSOLE)
+/*
+ *	Wait for transmitter & holding register to empty
+ */
+static void wait_for_xmitr(struct eg20t_port *up, int bits)
+{
+	unsigned int status, tmout = 10000;
+
+	/* Wait up to 10ms for the character(s) to be sent. */
+	for (;;) {
+		status = ioread8(up->membase + UART_LSR);
+
+		if ((status & bits) == bits)
+			break;
+		if (--tmout == 0)
+			break;
+		udelay(1);
+	}
+
+	/* Wait up to 1s for flow control if necessary */
+	if (up->port.flags & UPF_CONS_FLOW) {
+		unsigned int tmout;
+		for (tmout = 1000000; tmout; tmout--) {
+			unsigned int msr = ioread8(up->membase + UART_MSR);
+			if (msr & UART_MSR_CTS)
+				break;
+			udelay(1);
+			touch_nmi_watchdog();
+		}
+	}
+}
+#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_PCH_UART_CONSOLE */
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for communicate via uart while
+ * in an interrupt or debug context.
+ */
+static int pch_uart_get_poll_char(struct uart_port *port)
+{
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+	u8 lsr = ioread8(priv->membase + UART_LSR);
+
+	if (!(lsr & UART_LSR_DR))
+		return NO_POLL_CHAR;
+
+	return ioread8(priv->membase + PCH_UART_RBR);
+}
+
+
+static void pch_uart_put_poll_char(struct uart_port *port,
+			 unsigned char c)
+{
+	unsigned int ier;
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+
+	/*
+	 * First save the IER then disable the interrupts
+	 */
+	ier = ioread8(priv->membase + UART_IER);
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+
+	wait_for_xmitr(priv, UART_LSR_THRE);
+	/*
+	 * Send the character out.
+	 */
+	iowrite8(c, priv->membase + PCH_UART_THR);
+
+	/*
+	 * Finally, wait for transmitter to become empty
+	 * and restore the IER
+	 */
+	wait_for_xmitr(priv, UART_LSR_BOTH_EMPTY);
+	iowrite8(ier, priv->membase + UART_IER);
+}
+#endif /* CONFIG_CONSOLE_POLL */
+
+static const struct uart_ops pch_uart_ops = {
+	.tx_empty = pch_uart_tx_empty,
+	.set_mctrl = pch_uart_set_mctrl,
+	.get_mctrl = pch_uart_get_mctrl,
+	.stop_tx = pch_uart_stop_tx,
+	.start_tx = pch_uart_start_tx,
+	.stop_rx = pch_uart_stop_rx,
+	.enable_ms = pch_uart_enable_ms,
+	.break_ctl = pch_uart_break_ctl,
+	.startup = pch_uart_startup,
+	.shutdown = pch_uart_shutdown,
+	.set_termios = pch_uart_set_termios,
+/*	.pm		= pch_uart_pm,		Not supported yet */
+	.type = pch_uart_type,
+	.release_port = pch_uart_release_port,
+	.request_port = pch_uart_request_port,
+	.config_port = pch_uart_config_port,
+	.verify_port = pch_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char = pch_uart_get_poll_char,
+	.poll_put_char = pch_uart_put_poll_char,
+#endif
+};
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+
+static void pch_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	struct eg20t_port *priv =
+		container_of(port, struct eg20t_port, port);
+
+	wait_for_xmitr(priv, UART_LSR_THRE);
+	iowrite8(ch, priv->membase + PCH_UART_THR);
+}
+
+/*
+ *	Print a string to the serial port trying not to disturb
+ *	any possible real use of the port...
+ *
+ *	The console_lock must be held when we get here.
+ */
+static void
+pch_console_write(struct console *co, const char *s, unsigned int count)
+{
+	struct eg20t_port *priv;
+	unsigned long flags;
+	int priv_locked = 1;
+	int port_locked = 1;
+	u8 ier;
+
+	priv = pch_uart_ports[co->index];
+
+	touch_nmi_watchdog();
+
+	local_irq_save(flags);
+	if (priv->port.sysrq) {
+		/* call to uart_handle_sysrq_char already took the priv lock */
+		priv_locked = 0;
+		/* serial8250_handle_port() already took the port lock */
+		port_locked = 0;
+	} else if (oops_in_progress) {
+		priv_locked = spin_trylock(&priv->lock);
+		port_locked = spin_trylock(&priv->port.lock);
+	} else {
+		spin_lock(&priv->lock);
+		spin_lock(&priv->port.lock);
+	}
+
+	/*
+	 *	First save the IER then disable the interrupts
+	 */
+	ier = ioread8(priv->membase + UART_IER);
+
+	pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT);
+
+	uart_console_write(&priv->port, s, count, pch_console_putchar);
+
+	/*
+	 *	Finally, wait for transmitter to become empty
+	 *	and restore the IER
+	 */
+	wait_for_xmitr(priv, UART_LSR_BOTH_EMPTY);
+	iowrite8(ier, priv->membase + UART_IER);
+
+	if (port_locked)
+		spin_unlock(&priv->port.lock);
+	if (priv_locked)
+		spin_unlock(&priv->lock);
+	local_irq_restore(flags);
+}
+
+static int __init pch_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port;
+	int baud = default_baud;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (co->index >= PCH_UART_NR)
+		co->index = 0;
+	port = &pch_uart_ports[co->index]->port;
+
+	if (!port || (!port->iobase && !port->membase))
+		return -ENODEV;
+
+	port->uartclk = pch_uart_get_uartclk();
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver pch_uart_driver;
+
+static struct console pch_console = {
+	.name		= PCH_UART_DRIVER_DEVICE,
+	.write		= pch_console_write,
+	.device		= uart_console_device,
+	.setup		= pch_console_setup,
+	.flags		= CON_PRINTBUFFER | CON_ANYTIME,
+	.index		= -1,
+	.data		= &pch_uart_driver,
+};
+
+#define PCH_CONSOLE	(&pch_console)
+#else
+#define PCH_CONSOLE	NULL
+#endif	/* CONFIG_SERIAL_PCH_UART_CONSOLE */
+
+static struct uart_driver pch_uart_driver = {
+	.owner = THIS_MODULE,
+	.driver_name = KBUILD_MODNAME,
+	.dev_name = PCH_UART_DRIVER_DEVICE,
+	.major = 0,
+	.minor = 0,
+	.nr = PCH_UART_NR,
+	.cons = PCH_CONSOLE,
+};
+
+static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
+					     const struct pci_device_id *id)
+{
+	struct eg20t_port *priv;
+	int ret;
+	unsigned int iobase;
+	unsigned int mapbase;
+	unsigned char *rxbuf;
+	int fifosize;
+	int port_type;
+	struct pch_uart_driver_data *board;
+	char name[32];
+
+	board = &drv_dat[id->driver_data];
+	port_type = board->port_type;
+
+	priv = kzalloc(sizeof(struct eg20t_port), GFP_KERNEL);
+	if (priv == NULL)
+		goto init_port_alloc_err;
+
+	rxbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
+	if (!rxbuf)
+		goto init_port_free_txbuf;
+
+	switch (port_type) {
+	case PORT_PCH_8LINE:
+		fifosize = 256; /* EG20T/ML7213: UART0 */
+		break;
+	case PORT_PCH_2LINE:
+		fifosize = 64; /* EG20T:UART1~3  ML7213: UART1~2*/
+		break;
+	default:
+		dev_err(&pdev->dev, "Invalid Port Type(=%d)\n", port_type);
+		goto init_port_hal_free;
+	}
+
+	pci_enable_msi(pdev);
+	pci_set_master(pdev);
+
+	spin_lock_init(&priv->lock);
+
+	iobase = pci_resource_start(pdev, 0);
+	mapbase = pci_resource_start(pdev, 1);
+	priv->mapbase = mapbase;
+	priv->iobase = iobase;
+	priv->pdev = pdev;
+	priv->tx_empty = 1;
+	priv->rxbuf.buf = rxbuf;
+	priv->rxbuf.size = PAGE_SIZE;
+
+	priv->fifo_size = fifosize;
+	priv->uartclk = pch_uart_get_uartclk();
+	priv->port_type = port_type;
+	priv->port.dev = &pdev->dev;
+	priv->port.iobase = iobase;
+	priv->port.membase = NULL;
+	priv->port.mapbase = mapbase;
+	priv->port.irq = pdev->irq;
+	priv->port.iotype = UPIO_PORT;
+	priv->port.ops = &pch_uart_ops;
+	priv->port.flags = UPF_BOOT_AUTOCONF;
+	priv->port.fifosize = fifosize;
+	priv->port.line = board->line_no;
+	priv->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PCH_UART_CONSOLE);
+	priv->trigger = PCH_UART_HAL_TRIGGER_M;
+
+	snprintf(priv->irq_name, IRQ_NAME_SIZE,
+		 KBUILD_MODNAME ":" PCH_UART_DRIVER_DEVICE "%d",
+		 priv->port.line);
+
+	spin_lock_init(&priv->port.lock);
+
+	pci_set_drvdata(pdev, priv);
+	priv->trigger_level = 1;
+	priv->fcr = 0;
+
+	if (pdev->dev.of_node)
+		of_property_read_u32(pdev->dev.of_node, "clock-frequency"
+					 , &user_uartclk);
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[board->line_no] = priv;
+#endif
+	ret = uart_add_one_port(&pch_uart_driver, &priv->port);
+	if (ret < 0)
+		goto init_port_hal_free;
+
+	snprintf(name, sizeof(name), "uart%d_regs", priv->port.line);
+	debugfs_create_file(name, S_IFREG | S_IRUGO, NULL, priv,
+			    &port_regs_ops);
+
+	return priv;
+
+init_port_hal_free:
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[board->line_no] = NULL;
+#endif
+	free_page((unsigned long)rxbuf);
+init_port_free_txbuf:
+	kfree(priv);
+init_port_alloc_err:
+
+	return NULL;
+}
+
+static void pch_uart_exit_port(struct eg20t_port *priv)
+{
+	char name[32];
+
+	snprintf(name, sizeof(name), "uart%d_regs", priv->port.line);
+	debugfs_lookup_and_remove(name, NULL);
+	uart_remove_one_port(&pch_uart_driver, &priv->port);
+	free_page((unsigned long)priv->rxbuf.buf);
+}
+
+static void pch_uart_pci_remove(struct pci_dev *pdev)
+{
+	struct eg20t_port *priv = pci_get_drvdata(pdev);
+
+	pci_disable_msi(pdev);
+
+#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
+	pch_uart_ports[priv->port.line] = NULL;
+#endif
+	pch_uart_exit_port(priv);
+	pci_disable_device(pdev);
+	kfree(priv);
+	return;
+}
+
+static int __maybe_unused pch_uart_pci_suspend(struct device *dev)
+{
+	struct eg20t_port *priv = dev_get_drvdata(dev);
+
+	uart_suspend_port(&pch_uart_driver, &priv->port);
+
+	return 0;
+}
+
+static int __maybe_unused pch_uart_pci_resume(struct device *dev)
+{
+	struct eg20t_port *priv = dev_get_drvdata(dev);
+
+	uart_resume_port(&pch_uart_driver, &priv->port);
+
+	return 0;
+}
+
+static const struct pci_device_id pch_uart_pci_id[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8811),
+	 .driver_data = pch_et20t_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8812),
+	 .driver_data = pch_et20t_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8813),
+	 .driver_data = pch_et20t_uart2},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8814),
+	 .driver_data = pch_et20t_uart3},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8027),
+	 .driver_data = pch_ml7213_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8028),
+	 .driver_data = pch_ml7213_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8029),
+	 .driver_data = pch_ml7213_uart2},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x800C),
+	 .driver_data = pch_ml7223_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x800D),
+	 .driver_data = pch_ml7223_uart1},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8811),
+	 .driver_data = pch_ml7831_uart0},
+	{PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8812),
+	 .driver_data = pch_ml7831_uart1},
+	{0,},
+};
+
+static int pch_uart_pci_probe(struct pci_dev *pdev,
+					const struct pci_device_id *id)
+{
+	int ret;
+	struct eg20t_port *priv;
+
+	ret = pci_enable_device(pdev);
+	if (ret < 0)
+		goto probe_error;
+
+	priv = pch_uart_init_port(pdev, id);
+	if (!priv) {
+		ret = -EBUSY;
+		goto probe_disable_device;
+	}
+	pci_set_drvdata(pdev, priv);
+
+	return ret;
+
+probe_disable_device:
+	pci_disable_msi(pdev);
+	pci_disable_device(pdev);
+probe_error:
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(pch_uart_pci_pm_ops,
+			 pch_uart_pci_suspend,
+			 pch_uart_pci_resume);
+
+static struct pci_driver pch_uart_pci_driver = {
+	.name = "pch_uart",
+	.id_table = pch_uart_pci_id,
+	.probe = pch_uart_pci_probe,
+	.remove = pch_uart_pci_remove,
+	.driver.pm = &pch_uart_pci_pm_ops,
+};
+
+static int __init pch_uart_module_init(void)
+{
+	int ret;
+
+	/* register as UART driver */
+	ret = uart_register_driver(&pch_uart_driver);
+	if (ret < 0)
+		return ret;
+
+	/* register as PCI driver */
+	ret = pci_register_driver(&pch_uart_pci_driver);
+	if (ret < 0)
+		uart_unregister_driver(&pch_uart_driver);
+
+	return ret;
+}
+module_init(pch_uart_module_init);
+
+static void __exit pch_uart_module_exit(void)
+{
+	pci_unregister_driver(&pch_uart_pci_driver);
+	uart_unregister_driver(&pch_uart_driver);
+}
+module_exit(pch_uart_module_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel EG20T PCH UART PCI Driver");
+MODULE_DEVICE_TABLE(pci, pch_uart_pci_id);
+
+module_param(default_baud, uint, S_IRUGO);
+MODULE_PARM_DESC(default_baud,
+                 "Default BAUD for initial driver state and console (default 9600)");
+module_param(user_uartclk, uint, S_IRUGO);
+MODULE_PARM_DESC(user_uartclk,
+                 "Override UART default or board specific UART clock");