diff --git a/arch/alpha/kernel/srmcons.c b/arch/alpha/kernel/srmcons.c
index 6dc952b0df4a..dea39008d93e 100644
--- a/arch/alpha/kernel/srmcons.c
+++ b/arch/alpha/kernel/srmcons.c
@@ -130,8 +130,7 @@ srmcons_do_write(struct tty_port *port, const char *buf, int count)
 }
 
 static int
-srmcons_write(struct tty_struct *tty,
-	      const unsigned char *buf, int count)
+srmcons_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	unsigned long flags;
 
diff --git a/arch/m68k/emu/nfcon.c b/arch/m68k/emu/nfcon.c
index 6fdc13610565..e7a21234b481 100644
--- a/arch/m68k/emu/nfcon.c
+++ b/arch/m68k/emu/nfcon.c
@@ -70,8 +70,7 @@ static void nfcon_tty_close(struct tty_struct *tty, struct file *filp)
 {
 }
 
-static int nfcon_tty_write(struct tty_struct *tty, const unsigned char *buf,
-			   int count)
+static int nfcon_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	nfputs(buf, count);
 	return count;
diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 02b0befd6763..e5393b4ba9f8 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -184,7 +184,7 @@ void line_flush_chars(struct tty_struct *tty)
 	line_flush_buffer(tty);
 }
 
-int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
+int line_write(struct tty_struct *tty, const u8 *buf, int len)
 {
 	struct line *line = tty->driver_data;
 	unsigned long flags;
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index f15be75a3bf3..8354024b6b35 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -64,8 +64,7 @@ extern void line_cleanup(struct tty_struct *tty);
 extern void line_hangup(struct tty_struct *tty);
 extern int line_setup(char **conf, unsigned nlines, char **def,
 		      char *init, char *name);
-extern int line_write(struct tty_struct *tty, const unsigned char *buf,
-		      int len);
+extern int line_write(struct tty_struct *tty, const u8 *buf, int len);
 extern unsigned int line_chars_in_buffer(struct tty_struct *tty);
 extern void line_flush_buffer(struct tty_struct *tty);
 extern void line_flush_chars(struct tty_struct *tty);
diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c
index b40b73809dd8..182ec57e2d5c 100644
--- a/arch/xtensa/platforms/iss/console.c
+++ b/arch/xtensa/platforms/iss/console.c
@@ -52,8 +52,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp)
 }
 
 
-static int rs_write(struct tty_struct * tty,
-		    const unsigned char *buf, int count)
+static int rs_write(struct tty_struct * tty, const u8 *buf, int count)
 {
 	/* see drivers/char/serialX.c to reference original version */
 
diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c
index ed45d04905c2..4f3dd93f1fd8 100644
--- a/drivers/char/ttyprintk.c
+++ b/drivers/char/ttyprintk.c
@@ -51,7 +51,7 @@ static void tpk_flush(void)
 	}
 }
 
-static int tpk_printk(const unsigned char *buf, int count)
+static int tpk_printk(const u8 *buf, int count)
 {
 	int i;
 
@@ -103,8 +103,7 @@ static void tpk_close(struct tty_struct *tty, struct file *filp)
 /*
  * TTY operations write function.
  */
-static int tpk_write(struct tty_struct *tty,
-		const unsigned char *buf, int count)
+static int tpk_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct ttyprintk_port *tpkp = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/ipack/devices/ipoctal.c b/drivers/ipack/devices/ipoctal.c
index a01c15812b70..c3cf086e7e36 100644
--- a/drivers/ipack/devices/ipoctal.c
+++ b/drivers/ipack/devices/ipoctal.c
@@ -437,8 +437,7 @@ static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
 }
 
 static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
-					    const unsigned char *buf,
-					    int count)
+					    const u8 *buf, int count)
 {
 	unsigned long flags;
 	int i;
@@ -459,8 +458,7 @@ static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
 	return i;
 }
 
-static int ipoctal_write_tty(struct tty_struct *tty,
-			     const unsigned char *buf, int count)
+static int ipoctal_write_tty(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct ipoctal_channel *channel = tty->driver_data;
 	unsigned int char_copied;
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index 45a4043c5042..cf6daf79c1a2 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1077,8 +1077,7 @@ static void capinc_tty_close(struct tty_struct *tty, struct file *filp)
 	tty_port_close(&mp->port, tty, filp);
 }
 
-static int capinc_tty_write(struct tty_struct *tty,
-			    const unsigned char *buf, int count)
+static int capinc_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct capiminor *mp = tty->driver_data;
 	struct sk_buff *skb;
diff --git a/drivers/misc/bcm-vk/bcm_vk_tty.c b/drivers/misc/bcm-vk/bcm_vk_tty.c
index 6669625ba4c8..44851b607cce 100644
--- a/drivers/misc/bcm-vk/bcm_vk_tty.c
+++ b/drivers/misc/bcm-vk/bcm_vk_tty.c
@@ -186,9 +186,7 @@ static void bcm_vk_tty_doorbell(struct bcm_vk *vk, u32 db_val)
 		  VK_BAR0_REGSEG_DB_BASE + VK_BAR0_REGSEG_TTY_DB_OFFSET);
 }
 
-static int bcm_vk_tty_write(struct tty_struct *tty,
-			    const unsigned char *buffer,
-			    int count)
+static int bcm_vk_tty_write(struct tty_struct *tty, const u8 *buffer, int count)
 {
 	int index;
 	struct bcm_vk *vk;
diff --git a/drivers/mmc/core/sdio_uart.c b/drivers/mmc/core/sdio_uart.c
index aa659758563f..90d2fe00c0b9 100644
--- a/drivers/mmc/core/sdio_uart.c
+++ b/drivers/mmc/core/sdio_uart.c
@@ -760,8 +760,7 @@ static void sdio_uart_hangup(struct tty_struct *tty)
 	tty_port_hangup(&port->port);
 }
 
-static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
-			   int count)
+static int sdio_uart_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct sdio_uart_port *port = tty->driver_data;
 	int ret;
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index ce1f6081d582..014a9d29bab5 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -1322,8 +1322,7 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
 }
 
 /* close the requested serial port */
-static int hso_serial_write(struct tty_struct *tty, const unsigned char *buf,
-			    int count)
+static int hso_serial_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct hso_serial *serial = tty->driver_data;
 	int space, tx_bytes;
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index a1fef666c9b0..16b6f430dfd3 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -1021,8 +1021,7 @@ static unsigned int tty3215_write_room(struct tty_struct *tty)
 /*
  * String write routine for 3215 ttys
  */
-static int tty3215_write(struct tty_struct *tty,
-			 const unsigned char *buf, int count)
+static int tty3215_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	handle_write(tty->driver_data, buf, count);
 	return count;
diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c
index d9983550062d..123524bff734 100644
--- a/drivers/s390/char/con3270.c
+++ b/drivers/s390/char/con3270.c
@@ -1803,8 +1803,7 @@ static void tty3270_do_write(struct tty3270 *tp, struct tty_struct *tty,
 /*
  * String write routine for 3270 ttys
  */
-static int tty3270_write(struct tty_struct *tty,
-			 const unsigned char *buf, int count)
+static int tty3270_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct tty3270 *tp;
 
diff --git a/drivers/s390/char/sclp_tty.c b/drivers/s390/char/sclp_tty.c
index 971fbb52740b..cc0f6a97124e 100644
--- a/drivers/s390/char/sclp_tty.c
+++ b/drivers/s390/char/sclp_tty.c
@@ -230,7 +230,7 @@ static int sclp_tty_write_string(const unsigned char *str, int count, int may_fa
  * routine will return the number of characters actually accepted for writing.
  */
 static int
-sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+sclp_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	if (sclp_tty_chars_count > 0) {
 		sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c
index a32f34a1c6d2..44974d801c1e 100644
--- a/drivers/s390/char/sclp_vt220.c
+++ b/drivers/s390/char/sclp_vt220.c
@@ -463,7 +463,7 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
  * number of characters actually accepted for writing.
  */
 static int
-sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
+sclp_vt220_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	return __sclp_vt220_write(buf, count, 1, 0, 1);
 }
diff --git a/drivers/staging/gdm724x/gdm_tty.c b/drivers/staging/gdm724x/gdm_tty.c
index e1a84d6020f4..ae9978b73d9b 100644
--- a/drivers/staging/gdm724x/gdm_tty.c
+++ b/drivers/staging/gdm724x/gdm_tty.c
@@ -149,8 +149,7 @@ static void gdm_tty_send_complete(void *arg)
 	tty_port_tty_wakeup(&gdm->port);
 }
 
-static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf,
-			 int len)
+static int gdm_tty_write(struct tty_struct *tty, const u8 *buf, int len)
 {
 	struct gdm *gdm = tty->driver_data;
 	int remain = len;
diff --git a/drivers/staging/greybus/uart.c b/drivers/staging/greybus/uart.c
index 20a34599859f..97c7ddd0f53e 100644
--- a/drivers/staging/greybus/uart.c
+++ b/drivers/staging/greybus/uart.c
@@ -427,8 +427,7 @@ static void gb_tty_hangup(struct tty_struct *tty)
 	tty_port_hangup(&gb_tty->port);
 }
 
-static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf,
-			int count)
+static int gb_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct gb_tty *gb_tty = tty->driver_data;
 
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index c06ad0a0744b..1dd8b86f4a32 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -741,7 +741,7 @@ static void rs_flush_chars(struct tty_struct *tty)
 	local_irq_restore(flags);
 }
 
-static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
+static int rs_write(struct tty_struct * tty, const u8 *buf, int count)
 {
 	int	c, ret = 0;
 	struct serial_state *info = tty->driver_data;
diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
index 8595483f4697..de36347e2145 100644
--- a/drivers/tty/ehv_bytechan.c
+++ b/drivers/tty/ehv_bytechan.c
@@ -466,8 +466,7 @@ static irqreturn_t ehv_bc_tty_tx_isr(int irq, void *data)
  * ehv_bc_tty_write_room() will never lie, so the tty layer will never send us
  * too much data.
  */
-static int ehv_bc_tty_write(struct tty_struct *ttys, const unsigned char *s,
-			    int count)
+static int ehv_bc_tty_write(struct tty_struct *ttys, const u8 *s, int count)
 {
 	struct ehv_bc_data *bc = ttys->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
index d02de3f0326f..faa597ffbaf9 100644
--- a/drivers/tty/goldfish.c
+++ b/drivers/tty/goldfish.c
@@ -125,8 +125,7 @@ static void goldfish_tty_rw(struct goldfish_tty *qtty,
 	}
 }
 
-static void goldfish_tty_do_write(int line, const char *buf,
-				  unsigned int count)
+static void goldfish_tty_do_write(int line, const u8 *buf, unsigned int count)
 {
 	struct goldfish_tty *qtty = &goldfish_ttys[line];
 	unsigned long address = (unsigned long)(void *)buf;
@@ -186,8 +185,7 @@ static void goldfish_tty_hangup(struct tty_struct *tty)
 	tty_port_hangup(tty->port);
 }
 
-static int goldfish_tty_write(struct tty_struct *tty, const unsigned char *buf,
-								int count)
+static int goldfish_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	goldfish_tty_do_write(tty->index, buf, count);
 	return count;
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index 10c10cfdf92a..4c60d15c7a6f 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -496,7 +496,7 @@ static int hvc_push(struct hvc_struct *hp)
 	return n;
 }
 
-static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int hvc_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct hvc_struct *hp = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 1de1a09bf82d..2465d61b4e76 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1257,8 +1257,7 @@ static void hvcs_hangup(struct tty_struct * tty)
  * tty_hangup will allow hvcs_write time to complete execution before it
  * terminates our device.
  */
-static int hvcs_write(struct tty_struct *tty,
-		const unsigned char *buf, int count)
+static int hvcs_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct hvcs_struct *hvcsd = tty->driver_data;
 	unsigned int unit_address;
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index c1b8a4fd8b1e..46dd62df2442 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -904,8 +904,7 @@ static unsigned int hvsi_chars_in_buffer(struct tty_struct *tty)
 	return hp->n_outbuf;
 }
 
-static int hvsi_write(struct tty_struct *tty,
-		     const unsigned char *source, int count)
+static int hvsi_write(struct tty_struct *tty, const u8 *source, int count)
 {
 	struct hvsi_struct *hp = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/ipwireless/hardware.c b/drivers/tty/ipwireless/hardware.c
index f5d3e68f5750..001ec318a918 100644
--- a/drivers/tty/ipwireless/hardware.c
+++ b/drivers/tty/ipwireless/hardware.c
@@ -1292,7 +1292,7 @@ static void *alloc_ctrl_packet(int header_size,
 }
 
 int ipwireless_send_packet(struct ipw_hardware *hw, unsigned int channel_idx,
-			    const unsigned char *data, unsigned int length,
+			    const u8 *data, unsigned int length,
 			    void (*callback) (void *cb, unsigned int length),
 			    void *callback_data)
 {
diff --git a/drivers/tty/ipwireless/tty.c b/drivers/tty/ipwireless/tty.c
index 9edd5ae17580..cd43208c523c 100644
--- a/drivers/tty/ipwireless/tty.c
+++ b/drivers/tty/ipwireless/tty.c
@@ -186,8 +186,7 @@ static void ipw_write_packet_sent_callback(void *callback_data,
 	tty->tx_bytes_queued -= packet_length;
 }
 
-static int ipw_write(struct tty_struct *linux_tty,
-		     const unsigned char *buf, int count)
+static int ipw_write(struct tty_struct *linux_tty, const u8 *buf, int count)
 {
 	struct ipw_tty *tty = linux_tty->driver_data;
 	int room, ret;
diff --git a/drivers/tty/mips_ejtag_fdc.c b/drivers/tty/mips_ejtag_fdc.c
index e81701a66429..cf4ef0c38624 100644
--- a/drivers/tty/mips_ejtag_fdc.c
+++ b/drivers/tty/mips_ejtag_fdc.c
@@ -796,8 +796,8 @@ static void mips_ejtag_fdc_tty_hangup(struct tty_struct *tty)
 	tty_port_hangup(tty->port);
 }
 
-static int mips_ejtag_fdc_tty_write(struct tty_struct *tty,
-				    const unsigned char *buf, int total)
+static int mips_ejtag_fdc_tty_write(struct tty_struct *tty, const u8 *buf,
+				    int total)
 {
 	int count, block;
 	struct mips_ejtag_fdc_tty_port *dport = tty->driver_data;
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index 42fa4c878b2e..d94cf1be651b 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -487,7 +487,7 @@ module_param(ttymajor, int, 0);
  */
 static int moxa_open(struct tty_struct *, struct file *);
 static void moxa_close(struct tty_struct *, struct file *);
-static int moxa_write(struct tty_struct *, const unsigned char *, int);
+static int moxa_write(struct tty_struct *, const u8 *, int);
 static unsigned int moxa_write_room(struct tty_struct *);
 static void moxa_flush_buffer(struct tty_struct *);
 static unsigned int moxa_chars_in_buffer(struct tty_struct *);
@@ -1499,8 +1499,7 @@ static void moxa_close(struct tty_struct *tty, struct file *filp)
 	tty_port_close(&ch->port, tty, filp);
 }
 
-static int moxa_write(struct tty_struct *tty,
-		      const unsigned char *buf, int count)
+static int moxa_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct moxa_port *ch = tty->driver_data;
 	unsigned long flags;
@@ -2164,8 +2163,7 @@ static int MoxaPortLineStatus(struct moxa_port *port)
 	return val;
 }
 
-static int MoxaPortWriteData(struct tty_struct *tty,
-		const unsigned char *buffer, int len)
+static int MoxaPortWriteData(struct tty_struct *tty, const u8 *buffer, int len)
 {
 	struct moxa_port *port = tty->driver_data;
 	void __iomem *baseAddr, *ofsAddr, *ofs;
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 10855e66fda1..8b4b8493fed5 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -901,7 +901,7 @@ static void mxser_close(struct tty_struct *tty, struct file *filp)
 	tty_port_close(tty->port, tty, filp);
 }
 
-static int mxser_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int mxser_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct mxser_port *info = tty->driver_data;
 	unsigned long flags;
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index a3bd1fc52aed..d167e36873fe 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -4256,8 +4256,7 @@ static void gsmtty_hangup(struct tty_struct *tty)
 	gsm_dlci_begin_close(dlci);
 }
 
-static int gsmtty_write(struct tty_struct *tty, const unsigned char *buf,
-								    int len)
+static int gsmtty_write(struct tty_struct *tty, const u8 *buf, int len)
 {
 	int sent;
 	struct gsm_dlci *dlci = tty->driver_data;
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index 0454c78deee6..b3756402f5d9 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -1599,8 +1599,7 @@ static void ntty_hangup(struct tty_struct *tty)
  * called when the userspace process writes to the tty (/dev/noz*).
  * Data is inserted into a fifo, which is then read and transferred to the modem.
  */
-static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
-		      int count)
+static int ntty_write(struct tty_struct *tty, const u8 *buffer, int count)
 {
 	int rval = -EINVAL;
 	struct nozomi *dc = get_dc_by_tty(tty);
@@ -1610,7 +1609,7 @@ static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
 	if (!dc || !port)
 		return -ENODEV;
 
-	rval = kfifo_in(&port->fifo_ul, (unsigned char *)buffer, count);
+	rval = kfifo_in(&port->fifo_ul, buffer, count);
 
 	spin_lock_irqsave(&dc->spin_mutex, flags);
 	/* CTS is only valid on the modem channel */
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 2b1c8ab99dba..335f5744f320 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -108,7 +108,7 @@ static void pty_unthrottle(struct tty_struct *tty)
  *	the other side of the pty/tty pair.
  */
 
-static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
+static int pty_write(struct tty_struct *tty, const u8 *buf, int c)
 {
 	struct tty_struct *to = tty->link;
 
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
index 55c3c9db7462..2a04d19d5ec0 100644
--- a/drivers/tty/serial/kgdb_nmi.c
+++ b/drivers/tty/serial/kgdb_nmi.c
@@ -304,7 +304,7 @@ static unsigned int kgdb_nmi_tty_write_room(struct tty_struct *tty)
 	return 2048;
 }
 
-static int kgdb_nmi_tty_write(struct tty_struct *tty, const unchar *buf, int c)
+static int kgdb_nmi_tty_write(struct tty_struct *tty, const u8 *buf, int c)
 {
 	int i;
 
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index e31c9b6bd8ab..33df5b08d992 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -580,8 +580,7 @@ static void uart_flush_chars(struct tty_struct *tty)
 	uart_start(tty);
 }
 
-static int uart_write(struct tty_struct *tty,
-					const unsigned char *buf, int count)
+static int uart_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port;
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index 4c6366fe015c..c7cecea38ca8 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -431,7 +431,7 @@ static void tx_set_idle(struct slgt_info *info);
 static unsigned int tbuf_bytes(struct slgt_info *info);
 static void reset_tbufs(struct slgt_info *info);
 static void tdma_reset(struct slgt_info *info);
-static bool tx_load(struct slgt_info *info, const char *buf, unsigned int count);
+static bool tx_load(struct slgt_info *info, const u8 *buf, unsigned int count);
 
 static void get_gtsignals(struct slgt_info *info);
 static void set_gtsignals(struct slgt_info *info);
@@ -745,8 +745,7 @@ static void update_tx_timer(struct slgt_info *info)
 	}
 }
 
-static int write(struct tty_struct *tty,
-		 const unsigned char *buf, int count)
+static int write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	int ret = 0;
 	struct slgt_info *info = tty->driver_data;
@@ -4767,7 +4766,7 @@ static unsigned int tbuf_bytes(struct slgt_info *info)
  * load data into transmit DMA buffer ring and start transmitter if needed
  * return true if data accepted, otherwise false (buffers full)
  */
-static bool tx_load(struct slgt_info *info, const char *buf, unsigned int size)
+static bool tx_load(struct slgt_info *info, const u8 *buf, unsigned int size)
 {
 	unsigned short count;
 	unsigned int i;
diff --git a/drivers/tty/ttynull.c b/drivers/tty/ttynull.c
index 1d4438472442..6b74ebaa0f2d 100644
--- a/drivers/tty/ttynull.c
+++ b/drivers/tty/ttynull.c
@@ -29,8 +29,7 @@ static void ttynull_hangup(struct tty_struct *tty)
 	tty_port_hangup(&ttynull_port);
 }
 
-static int ttynull_write(struct tty_struct *tty, const unsigned char *buf,
-			 int count)
+static int ttynull_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	return count;
 }
diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
index 34ba6e54789a..c223879039b8 100644
--- a/drivers/tty/vcc.c
+++ b/drivers/tty/vcc.c
@@ -804,8 +804,7 @@ static void vcc_hangup(struct tty_struct *tty)
 	tty_port_hangup(tty->port);
 }
 
-static int vcc_write(struct tty_struct *tty, const unsigned char *buf,
-		     int count)
+static int vcc_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct vcc_port *port;
 	struct vio_vcc *pkt;
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index cf77011a8f4e..2f28612aee91 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -2845,7 +2845,7 @@ static int vc_con_write_normal(struct vc_data *vc, int tc, int c,
 }
 
 /* acquires console_lock */
-static int do_con_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int do_con_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct vc_draw_region draw = {
 		.x = -1,
@@ -3238,7 +3238,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg)
  * /dev/ttyN handling
  */
 
-static int con_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int con_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	int	retval;
 
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 11da5fb284d0..913b07b30d33 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -789,8 +789,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 	tty_port_close(&acm->port, tty, filp);
 }
 
-static int acm_tty_write(struct tty_struct *tty,
-					const unsigned char *buf, int count)
+static int acm_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct acm *acm = tty->driver_data;
 	int stat;
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 1115396b46a0..1d08a1d8d3cd 100644
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -734,7 +734,7 @@ static void gs_close(struct tty_struct *tty, struct file *file)
 	spin_unlock_irq(&port->port_lock);
 }
 
-static int gs_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int gs_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct gs_port	*port = tty->driver_data;
 	unsigned long	flags;
diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index d3acc0829ee5..f5f2d0e12e69 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -208,9 +208,7 @@ static void dbc_tty_close(struct tty_struct *tty, struct file *file)
 	tty_port_close(&port->port, tty, file);
 }
 
-static int dbc_tty_write(struct tty_struct *tty,
-			 const unsigned char *buf,
-			 int count)
+static int dbc_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct dbc_port		*port = tty->driver_data;
 	unsigned long		flags;
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 7b4805c1004d..51f738ea3f77 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -361,8 +361,7 @@ static void serial_cleanup(struct tty_struct *tty)
 	module_put(owner);
 }
 
-static int serial_write(struct tty_struct *tty, const unsigned char *buf,
-								int count)
+static int serial_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct usb_serial_port *port = tty->driver_data;
 	int retval = -ENODEV;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index e00034118c7b..a7bd8060ac96 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -356,8 +356,7 @@ struct tty_operations {
 	void (*close)(struct tty_struct * tty, struct file * filp);
 	void (*shutdown)(struct tty_struct *tty);
 	void (*cleanup)(struct tty_struct *tty);
-	int  (*write)(struct tty_struct * tty,
-		      const unsigned char *buf, int count);
+	int  (*write)(struct tty_struct *tty, const u8 *buf, int count);
 	int  (*put_char)(struct tty_struct *tty, unsigned char ch);
 	void (*flush_chars)(struct tty_struct *tty);
 	unsigned int (*write_room)(struct tty_struct *tty);
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index d73eec146529..3b5f8404dc84 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -779,7 +779,7 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 	tty_port_close(&dev->port, tty, filp);
 }
 
-static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
+static int rfcomm_tty_write(struct tty_struct *tty, const u8 *buf, int count)
 {
 	struct rfcomm_dev *dev = tty->driver_data;
 	struct rfcomm_dlc *dlc = dev->dlc;
