[PATCH 3/4] serial: sh-sci: Add more register documentation

[Geert Uytterhoeven <geert@linux-m68k.org>]

From: Geert Uytterhoeven <geert+renesas@linux-m68k.org>

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
---
 drivers/tty/serial/sh-sci.c |   28 +++++++------
 include/linux/serial_sci.h  |   93 +++++++++++++++++++++++++++----------------
 2 files changed, 73 insertions(+), 48 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 4529dbca2287..e0c7db0027b7 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -911,7 +911,7 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 		/* Disable future Rx interrupts */
 		if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 			disable_irq_nosync(irq);
-			scr |= 0x4000;
+			scr |= SCSCR_RDRQE;
 		} else {
 			scr &= ~SCSCR_RIE;
 		}
@@ -1200,7 +1200,9 @@ static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		 */
 		reg = sci_getreg(port, SCFCR);
 		if (reg->size)
-			serial_port_out(port, SCFCR, serial_port_in(port, SCFCR) | 1);
+			serial_port_out(port, SCFCR,
+					serial_port_in(port, SCFCR) |
+					SCFCR_LOOP);
 	}
 }
 
@@ -1496,9 +1498,9 @@ static void sci_start_tx(struct uart_port *port)
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 		u16 new, scr = serial_port_in(port, SCSCR);
 		if (s->chan_tx)
-			new = scr | 0x8000;
+			new = scr | SCSCR_TDRQE;
 		else
-			new = scr & ~0x8000;
+			new = scr & ~SCSCR_TDRQE;
 		if (new != scr)
 			serial_port_out(port, SCSCR, new);
 	}
@@ -1525,7 +1527,7 @@ static void sci_stop_tx(struct uart_port *port)
 	ctrl = serial_port_in(port, SCSCR);
 
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
-		ctrl &= ~0x8000;
+		ctrl &= ~SCSCR_TDRQE;
 
 	ctrl &= ~SCSCR_TIE;
 
@@ -1539,7 +1541,7 @@ static void sci_start_rx(struct uart_port *port)
 	ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
-		ctrl &= ~0x4000;
+		ctrl &= ~SCSCR_RDRQE;
 
 	serial_port_out(port, SCSCR, ctrl);
 }
@@ -1551,7 +1553,7 @@ static void sci_stop_rx(struct uart_port *port)
 	ctrl = serial_port_in(port, SCSCR);
 
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
-		ctrl &= ~0x4000;
+		ctrl &= ~SCSCR_RDRQE;
 
 	ctrl &= ~port_rx_irq_mask(port);
 
@@ -1614,7 +1616,7 @@ static void rx_timer_fn(unsigned long arg)
 	u16 scr = serial_port_in(port, SCSCR);
 
 	if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
-		scr &= ~0x4000;
+		scr &= ~SCSCR_RDRQE;
 		enable_irq(s->irqs[SCIx_RXI_IRQ]);
 	}
 	serial_port_out(port, SCSCR, scr | SCSCR_RIE);
@@ -1871,13 +1873,13 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 	smr_val = serial_port_in(port, SCSMR) & 3;
 
 	if ((termios->c_cflag & CSIZE) == CS7)
-		smr_val |= 0x40;
+		smr_val |= SCSMR_CHR;
 	if (termios->c_cflag & PARENB)
-		smr_val |= 0x20;
+		smr_val |= SCSMR_PE;
 	if (termios->c_cflag & PARODD)
-		smr_val |= 0x30;
+		smr_val |= SCSMR_PE | SCSMR_ODD;
 	if (termios->c_cflag & CSTOPB)
-		smr_val |= 0x08;
+		smr_val |= SCSMR_STOP;
 
 	uart_update_timeout(port, termios->c_cflag, baud);
 
@@ -1885,7 +1887,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 		__func__, smr_val, cks, t, s->cfg->scscr);
 
 	if (t >= 0) {
-		serial_port_out(port, SCSMR, (smr_val & ~3) | cks);
+		serial_port_out(port, SCSMR, (smr_val & ~SCSMR_CKS) | cks);
 		serial_port_out(port, SCBRR, t);
 		reg = sci_getreg(port, HSSRR);
 		if (reg->size)
diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index 22b3640c9424..6c5e3bb282b0 100644
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -10,45 +10,59 @@
 
 #define SCIx_NOT_SUPPORTED	(-1)
 
-#define SCSCR_TIE	(1 << 7)
-#define SCSCR_RIE	(1 << 6)
-#define SCSCR_TE	(1 << 5)
-#define SCSCR_RE	(1 << 4)
-#define SCSCR_REIE	(1 << 3)	/* not supported by all parts */
-#define SCSCR_TOIE	(1 << 2)	/* not supported by all parts */
-#define SCSCR_CKE1	(1 << 1)
-#define SCSCR_CKE0	(1 << 0)
-
-/* SCxSR SCI */
-#define SCI_TDRE  0x80
-#define SCI_RDRF  0x40
-#define SCI_ORER  0x20
-#define SCI_FER   0x10
-#define SCI_PER   0x08
-#define SCI_TEND  0x04
+/* SCSMR (Serial Mode Register) */
+#define SCSMR_CHR	(1 << 6)	/* 7-bit Character Length */
+#define SCSMR_PE	(1 << 5)	/* Parity Enable */
+#define SCSMR_ODD	(1 << 4)	/* Odd Parity */
+#define SCSMR_STOP	(1 << 3)	/* Stop Bit Length */
+#define SCSMR_CKS	0x0003		/* Clock Select */
+
+/* Serial Control Register (@ = not supported by all parts) */
+#define SCSCR_TIE	(1 << 7)	/* Transmit Interrupt Enable */
+#define SCSCR_RIE	(1 << 6)	/* Receive Interrupt Enable */
+#define SCSCR_TE	(1 << 5)	/* Transmit Enable */
+#define SCSCR_RE	(1 << 4)	/* Receive Enable */
+#define SCSCR_REIE	(1 << 3)	/* Receive Error Interrupt Enable @ */
+#define SCSCR_TOIE	(1 << 2)	/* Timeout Interrupt Enable @ */
+#define SCSCR_CKE1	(1 << 1)	/* Clock Enable 1 */
+#define SCSCR_CKE0	(1 << 0)	/* Clock Enable 0 */
+/* SCIFA/SCIFB only */
+#define SCSCR_TDRQE	(1 << 15)	/* Tx Data Transfer Request Enable */
+#define SCSCR_RDRQE	(1 << 14)	/* Rx Data Transfer Request Enable */
+
+/* SCxSR (Serial Status Register) on SCI */
+#define SCI_TDRE  0x80			/* Transmit Data Register Empty */
+#define SCI_RDRF  0x40			/* Receive Data Register Full */
+#define SCI_ORER  0x20			/* Overrun Error */
+#define SCI_FER   0x10			/* Framing Error */
+#define SCI_PER   0x08			/* Parity Error */
+#define SCI_TEND  0x04			/* Transmit End */
 
 #define SCI_DEFAULT_ERROR_MASK (SCI_PER | SCI_FER)
 
-/* SCxSR SCIF, HSCIF */
-#define SCIF_ER    0x0080
-#define SCIF_TEND  0x0040
-#define SCIF_TDFE  0x0020
-#define SCIF_BRK   0x0010
-#define SCIF_FER   0x0008
-#define SCIF_PER   0x0004
-#define SCIF_RDF   0x0002
-#define SCIF_DR    0x0001
+/* SCxSR (Serial Status Register) on SCIF, HSCIF */
+#define SCIF_ER    0x0080		/* Receive Error */
+#define SCIF_TEND  0x0040		/* Transmission End */
+#define SCIF_TDFE  0x0020		/* Transmit FIFO Data Empty */
+#define SCIF_BRK   0x0010		/* Break Detect */
+#define SCIF_FER   0x0008		/* Framing Error */
+#define SCIF_PER   0x0004		/* Parity Error */
+#define SCIF_RDF   0x0002		/* Receive FIFO Data Full */
+#define SCIF_DR    0x0001		/* Receive Data Ready */
 
 #define SCIF_DEFAULT_ERROR_MASK (SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK)
 
-/* SCSPTR, optional */
-#define SCSPTR_RTSIO	(1 << 7)
-#define SCSPTR_CTSIO	(1 << 5)
-#define SCSPTR_SPB2IO	(1 << 1)
-#define SCSPTR_SPB2DT	(1 << 0)
+/* SCFCR (FIFO Control Register) */
+#define SCFCR_LOOP	(1 << 0)	/* Loopback Test */
+
+/* SCSPTR (Serial Port Register), optional */
+#define SCSPTR_RTSIO	(1 << 7)	/* Serial Port RTS Pin Input/Output */
+#define SCSPTR_CTSIO	(1 << 5)	/* Serial Port CTS Pin Input/Output */
+#define SCSPTR_SPB2IO	(1 << 1)	/* Serial Port Break Input/Output */
+#define SCSPTR_SPB2DT	(1 << 0)	/* Serial Port Break Data */
 
 /* HSSRR HSCIF */
-#define HSCIF_SRE	0x8000
+#define HSCIF_SRE	0x8000		/* Sampling Rate Register Enable */
 
 enum {
 	SCIx_PROBE_REGTYPE,
@@ -73,10 +87,19 @@ enum {
  * Not all registers will exist on all parts.
  */
 enum {
-	SCSMR, SCBRR, SCSCR, SCxSR,
-	SCFCR, SCFDR, SCxTDR, SCxRDR,
-	SCLSR, SCTFDR, SCRFDR, SCSPTR,
-	HSSRR,
+	SCSMR,				/* Serial Mode Register */
+	SCBRR,				/* Bit Rate Register */
+	SCSCR,				/* Serial Control Register */
+	SCxSR,				/* Serial Status Register */
+	SCFCR,				/* FIFO Control Register */
+	SCFDR,				/* FIFO Data Count Register */
+	SCxTDR,				/* Transmit (FIFO) Data Register */
+	SCxRDR,				/* Receive (FIFO) Data Register */
+	SCLSR,				/* Line Status Register */
+	SCTFDR,				/* Transmit FIFO Data Count Register */
+	SCRFDR,				/* Receive FIFO Data Count Register */
+	SCSPTR,				/* Serial Port Register */
+	HSSRR,				/* Sampling Rate Register */
 
 	SCIx_NR_REGS,
 };
-- 
1.7.9.5