serial: sh-sci: Add support for RZ/V2H(P) SoC

Add serial support for RZ/V2H(P) SoC with earlycon.

The SCIF interface in the Renesas RZ/V2H(P) is similar to that available
in the RZ/G2L (R9A07G044) SoC, with the following differences:

- RZ/V2H(P) SoC has three additional interrupts: one for Tx end/Rx ready
  and two for Rx and Tx buffer full, all of which are edge-triggered.
- RZ/V2H(P) supports asynchronous mode, whereas RZ/G2L supports both
  synchronous and asynchronous modes.
- There are differences in the configuration of certain registers such
  as SCSMR, SCFCR, and SCSPTR between the two SoCs.

To handle these differences on RZ/V2H(P) SoC SCIx_RZV2H_SCIF_REGTYPE
is added.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240604170513.522631-6-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/sh-sci.c

@@ -317,6 +317,37 @@ static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
 		.error_clear = SCIF_ERROR_CLEAR,
 	},
 
+	/*
+	 * The "SCIF" that is in RZ/V2H(P) SoC is similar to one found on RZ/G2L SoC
+	 * with below differences,
+	 * - Break out of interrupts are different: ERI, BRI, RXI, TXI, TEI, DRI,
+	 *   TEI-DRI, RXI-EDGE and TXI-EDGE.
+	 * - SCSMR register does not have CM bit (BIT(7)) ie it does not support synchronous mode.
+	 * - SCFCR register does not have SCFCR_MCE bit.
+	 * - SCSPTR register has only bits SCSPTR_SPB2DT and SCSPTR_SPB2IO.
+	 */
+	[SCIx_RZV2H_SCIF_REGTYPE] = {
+		.regs = {
+			[SCSMR]		= { 0x00, 16 },
+			[SCBRR]		= { 0x02,  8 },
+			[SCSCR]		= { 0x04, 16 },
+			[SCxTDR]	= { 0x06,  8 },
+			[SCxSR]		= { 0x08, 16 },
+			[SCxRDR]	= { 0x0a,  8 },
+			[SCFCR]		= { 0x0c, 16 },
+			[SCFDR]		= { 0x0e, 16 },
+			[SCSPTR]	= { 0x10, 16 },
+			[SCLSR]		= { 0x12, 16 },
+			[SEMR]		= { 0x14, 8 },
+		},
+		.fifosize = 16,
+		.overrun_reg = SCLSR,
+		.overrun_mask = SCLSR_ORER,
+		.sampling_rate_mask = SCI_SR(32),
+		.error_mask = SCIF_DEFAULT_ERROR_MASK,
+		.error_clear = SCIF_ERROR_CLEAR,
+	},
+
 	/*
 	 * Common SH-3 SCIF definitions.
 	 */
@@ -757,7 +788,7 @@ static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 		}
 		sci_serial_out(port, SCPDR, data);
 		sci_serial_out(port, SCPCR, ctrl);
-	} else if (sci_getreg(port, SCSPTR)->size) {
+	} else if (sci_getreg(port, SCSPTR)->size && s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE) {
 		u16 status = sci_serial_in(port, SCSPTR);
 
 		/* RTS# is always output; and active low, unless autorts */
@@ -2124,8 +2155,9 @@ static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	if (!(mctrl & TIOCM_RTS)) {
 		/* Disable Auto RTS */
-		sci_serial_out(port, SCFCR,
-			       sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
+		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
+			sci_serial_out(port, SCFCR,
+				       sci_serial_in(port, SCFCR) & ~SCFCR_MCE);
 
 		/* Clear RTS */
 		sci_set_rts(port, 0);
@@ -2137,8 +2169,9 @@ static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
 		}
 
 		/* Enable Auto RTS */
-		sci_serial_out(port, SCFCR,
-			       sci_serial_in(port, SCFCR) | SCFCR_MCE);
+		if (s->cfg->regtype != SCIx_RZV2H_SCIF_REGTYPE)
+			sci_serial_out(port, SCFCR,
+				       sci_serial_in(port, SCFCR) | SCFCR_MCE);
 	} else {
 		/* Set RTS */
 		sci_set_rts(port, 1);
@@ -3225,6 +3258,10 @@ static const struct of_device_id of_sci_match[] __maybe_unused = {
 		.compatible = "renesas,scif-r9a07g044",
 		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
 	},
+	{
+		.compatible = "renesas,scif-r9a09g057",
+		.data = SCI_OF_DATA(PORT_SCIF, SCIx_RZV2H_SCIF_REGTYPE),
+	},
 	/* Family-specific types */
 	{
 		.compatible = "renesas,rcar-gen1-scif",
@@ -3533,6 +3570,13 @@ static int __init rzscifa_early_console_setup(struct earlycon_device *device,
 	return early_console_setup(device, PORT_SCIF);
 }
 
+static int __init rzv2hscif_early_console_setup(struct earlycon_device *device,
+						const char *opt)
+{
+	port_cfg.regtype = SCIx_RZV2H_SCIF_REGTYPE;
+	return early_console_setup(device, PORT_SCIF);
+}
+
 static int __init scifa_early_console_setup(struct earlycon_device *device,
 					  const char *opt)
 {
@@ -3553,6 +3597,7 @@ OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
 OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a07g044", rzscifa_early_console_setup);
+OF_EARLYCON_DECLARE(scif, "renesas,scif-r9a09g057", rzv2hscif_early_console_setup);
 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);

include/linux/serial_sci.h

@@ -37,6 +37,7 @@ enum {
 	SCIx_SH7705_SCIF_REGTYPE,
 	SCIx_HSCIF_REGTYPE,
 	SCIx_RZ_SCIFA_REGTYPE,
+	SCIx_RZV2H_SCIF_REGTYPE,
 
 	SCIx_NR_REGTYPES,
 };