Revert "serial: Airoha SoC UART and HSUART support"

This reverts commit e12ebf14fa3654f68589292e645ae1ef74786638.

It causes build errors in linux-next.

Cc: Benjamin Larsson <benjamin.larsson@genexis.eu>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20250206135328.4bad1401@canb.auug.org.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

6 files changed, 0 insertions, 135 deletions

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 2ebfd94a5818..11e05aa014e5 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -314,21 +314,6 @@ static inline int serial8250_in_MCR(struct uart_8250_port *up)
 	return mctrl;
 }
 
-/* uart_config[] table port type defines */
-/* Airoha UART */
-#define PORT_AIROHA	124
-
-/* Airoha HSUART */
-#define PORT_AIROHA_HS	125
-
-#ifdef CONFIG_SERIAL_8250_AIROHA
-void airoha8250_set_baud_rate(struct uart_port *port,
-			     unsigned int baud, unsigned int hs);
-#else
-static inline void airoha8250_set_baud_rate(struct uart_port *port,
-			     unsigned int baud, unsigned int hs) { }
-#endif
-
 #ifdef CONFIG_SERIAL_8250_PNP
 int serial8250_pnp_init(void);
 void serial8250_pnp_exit(void);
diff --git a/drivers/tty/serial/8250/8250_airoha.c b/drivers/tty/serial/8250/8250_airoha.c
deleted file mode 100644
index 51e675605741..000000000000
--- a/drivers/tty/serial/8250/8250_airoha.c
+++ /dev/null
@@ -1,81 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-
-/*
- * Airoha UART baud rate calculation function
- *
- * Copyright (c) 2025 Genexis Sweden AB
- * Author: Benjamin Larsson <benjamin.larsson@genexis.eu>
- */
-
-#include "8250.h"
-
-/* The Airoha UART is 16550-compatible except for the baud rate calculation. */
-
-/* Airoha UART registers */
-#define UART_AIROHA_BRDL	0
-#define UART_AIROHA_BRDH	1
-#define UART_AIROHA_XINCLKDR	10
-#define UART_AIROHA_XYD		11
-
-#define XYD_Y 65000
-#define XINDIV_CLOCK 20000000
-#define UART_BRDL_20M 0x01
-#define UART_BRDH_20M 0x00
-
-static const int clock_div_tab[] = { 10, 4, 2};
-static const int clock_div_reg[] = {  4, 2, 1};
-
-/**
- * airoha8250_set_baud_rate() - baud rate calculation routine
- * @port: uart port
- * @baud: requested uart baud rate
- * @hs: uart type selector, 0 for regular uart and 1 for high-speed uart
- *
- * crystal_clock = 20 MHz (fixed frequency)
- * xindiv_clock = crystal_clock / clock_div
- * (x/y) = XYD, 32 bit register with 16 bits of x and then 16 bits of y
- * clock_div = XINCLK_DIVCNT (default set to 10 (0x4)),
- *           - 3 bit register [ 1, 2, 4, 8, 10, 12, 16, 20 ]
- *
- * baud_rate = ((xindiv_clock) * (x/y)) / ([BRDH,BRDL] * 16)
- *
- * Selecting divider needs to fulfill
- * 1.8432 MHz <= xindiv_clk <= APB clock / 2
- * The clocks are unknown but a divider of value 1 did not result in a valid
- * waveform.
- *
- * XYD_y seems to need to be larger then XYD_x for proper waveform generation.
- * Setting [BRDH,BRDL] to [0,1] and XYD_y to 65000 gives even values
- * for usual baud rates.
- */
-
-void airoha8250_set_baud_rate(struct uart_port *port,
-			     unsigned int baud, unsigned int hs)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned int xyd_x, nom, denom;
-	int i;
-
-	/* set DLAB to access the baud rate divider registers (BRDH, BRDL) */
-	serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB);
-	/* set baud rate calculation defaults */
-	/* set BRDIV ([BRDH,BRDL]) to 1 */
-	serial_port_out(port, UART_AIROHA_BRDL, UART_BRDL_20M);
-	serial_port_out(port, UART_AIROHA_BRDH, UART_BRDH_20M);
-	/* calculate XYD_x and XINCLKDR register by searching
-	 * through a table of crystal_clock divisors
-	 *
-	 * for the HSUART xyd_x needs to be scaled by a factor of 2
-	 */
-	for (i = 0 ; i < ARRAY_SIZE(clock_div_tab) ; i++) {
-		denom = (XINDIV_CLOCK/40) / clock_div_tab[i];
-		nom = baud * (XYD_Y/40);
-		xyd_x = ((nom/denom) << 4) >> hs;
-		if (xyd_x < XYD_Y)
-			break;
-	}
-	serial_port_out(port, UART_AIROHA_XINCLKDR, clock_div_reg[i]);
-	serial_port_out(port, UART_AIROHA_XYD, (xyd_x<<16) | XYD_Y);
-	/* unset DLAB */
-	serial_port_out(port, UART_LCR, up->lcr);
-}
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 5315bc1bc06d..64aed7efc569 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -341,8 +341,6 @@ static const struct of_device_id of_platform_serial_table[] = {
 	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
 	{ .compatible = "nuvoton,wpcm450-uart", .data = (void *)PORT_NPCM, },
 	{ .compatible = "nuvoton,npcm750-uart", .data = (void *)PORT_NPCM, },
-	{ .compatible = "airoha,airoha-uart", .data = (void *)PORT_AIROHA, },
-	{ .compatible = "airoha,airoha-hsuart", .data = (void *)PORT_AIROHA_HS, },
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(of, of_platform_serial_table);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 5afbc988dcc3..d7976a21cca9 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -319,24 +319,6 @@ static const struct serial8250_config uart_config[] = {
 		.rxtrig_bytes	= {1, 8, 16, 30},
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
-	/* From here on after additional uart config port defines are placed in 8250.h
-	 */
-	[PORT_AIROHA] = {
-		.name		= "Airoha UART",
-		.fifo_size	= 8,
-		.tx_loadsz	= 1,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_CLEAR_RCVR,
-		.rxtrig_bytes	= {1, 4},
-		.flags		= UART_CAP_FIFO,
-	},
-	[PORT_AIROHA_HS] = {
-		.name		= "Airoha HSUART",
-		.fifo_size	= 128,
-		.tx_loadsz	= 128,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01 | UART_FCR_CLEAR_RCVR,
-		.rxtrig_bytes	= {1, 4},
-		.flags		= UART_CAP_FIFO,
-	},
 };
 
 /* Uart divisor latch read */
@@ -2884,14 +2866,6 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	serial8250_set_divisor(port, baud, quot, frac);
 
 	/*
-	 * Airoha SoCs have custom registers for baud rate settings
-	 */
-	if (port->type == PORT_AIROHA)
-		airoha8250_set_baud_rate(port, baud, 0);
-	if (port->type == PORT_AIROHA_HS)
-		airoha8250_set_baud_rate(port, baud, 1);
-
-	/*
 	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
 	 * is written without DLAB set, this mode will be disabled.
 	 */
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 97fe6ea9393d..55d26d16df9b 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -356,16 +356,6 @@ config SERIAL_8250_ACORN
 	  system, say Y to this option.  The driver can handle 1, 2, or 3 port
 	  cards.  If unsure, say N.
 
-config SERIAL_8250_AIROHA
-	tristate "Airoha UART support"
-	depends on (ARCH_AIROHA || COMPILE_TEST) && OF && SERIAL_8250
-	help
-	  Selecting this option enables an Airoha SoC specific baud rate
-	  calculation routine on an otherwise 16550 compatible UART hardware.
-
-	  If you have an Airoha based board and want to use the serial port,
-	  say Y to this option. If unsure, say N.
-
 config SERIAL_8250_BCM2835AUX
 	tristate "BCM2835 auxiliar mini UART support"
 	depends on ARCH_BCM2835 || COMPILE_TEST
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index b7f07d5c4cca..1516de629b61 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -20,7 +20,6 @@ obj-$(CONFIG_SERIAL_8250_CONSOLE)	+= 8250_early.o
 
 obj-$(CONFIG_SERIAL_8250_ACCENT)	+= 8250_accent.o
 obj-$(CONFIG_SERIAL_8250_ACORN)		+= 8250_acorn.o
-obj-$(CONFIG_SERIAL_8250_AIROHA)	+= 8250_airoha.o
 obj-$(CONFIG_SERIAL_8250_ASPEED_VUART)	+= 8250_aspeed_vuart.o
 obj-$(CONFIG_SERIAL_8250_BCM2835AUX)	+= 8250_bcm2835aux.o
 obj-$(CONFIG_SERIAL_8250_BCM7271)	+= 8250_bcm7271.o