Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-26 06:02:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

tty: serial: sh-sci: Add support for tx end interrupt handling

Browse Source 
As per the RZ/G2L users hardware manual (Rev.1.20 Sep, 2022), section
23.3.7 Serial Data Transmission (Asynchronous Mode), it is mentioned
that, set the SCR.TIE bit to 0 and SCR.TEIE bit to 1, after the last
data to be transmitted are written to the TDR.

This will generate tx end interrupt and in the handler set SCR.TE and
SCR.TEIE to 0.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230412145053.114847-5-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Biju Das 2023-04-12 15:50:52 +01:00 committed by Greg Kroah-Hartman
parent 1707ce2d1e
commit d61ae331d6
2 changed files with 31 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
drivers/tty/serial/sh-sci.c
View File

@ -860,9 +860,16 @@ static void sci_transmit_chars(struct uart_port *port)
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (uart_circ_empty(xmit))
sci_stop_tx(port);
if (uart_circ_empty(xmit)) {
if (port->type == PORT_SCI) {
ctrl = serial_port_in(port, SCSCR);
ctrl &= ~SCSCR_TIE;
ctrl |= SCSCR_TEIE;
serial_port_out(port, SCSCR, ctrl);
}
sci_stop_tx(port);
}
}
static void sci_receive_chars(struct uart_port *port)
@ -1766,6 +1773,24 @@ static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
return IRQ_HANDLED;
}
static irqreturn_t sci_tx_end_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
unsigned long flags;
unsigned short ctrl;
if (port->type != PORT_SCI)
return sci_tx_interrupt(irq, ptr);
spin_lock_irqsave(&port->lock, flags);
ctrl = serial_port_in(port, SCSCR);
ctrl &= ~(SCSCR_TE | SCSCR_TEIE);
serial_port_out(port, SCSCR, ctrl);
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t sci_br_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
@ -1902,7 +1927,7 @@ static const struct sci_irq_desc {
[SCIx_TEI_IRQ] = {
.desc = "tx end",
.handler = sci_tx_interrupt,
.handler = sci_tx_end_interrupt,
},
/*

3
drivers/tty/serial/sh-sci.h
View File

@ -59,6 +59,9 @@ enum {
#define SCSMR_SRC_19 0x0600 /* Sampling rate 1/19 */
#define SCSMR_SRC_27 0x0700 /* Sampling rate 1/27 */
/* Serial Control Register, SCI only bits */
#define SCSCR_TEIE BIT(2) /* Transmit End Interrupt Enable */
/* Serial Control Register, SCIFA/SCIFB only bits */
#define SCSCR_TDRQE BIT(15) /* Tx Data Transfer Request Enable */
#define SCSCR_RDRQE BIT(14) /* Rx Data Transfer Request Enable */