tty: serial: samsung: Add ARTPEC-8 support

Add support for the UART block on the ARTPEC-8 SoC.  This is closely
related to the variants used on the Exynos chips.  The register layout
is identical to Exynos850 et al but the fifo size is different (64 bytes
in each direction for all instances).

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20220311094515.3223023-3-vincent.whitchurch@axis.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: vwax

drivers/tty/serial/Kconfig

@@ -237,7 +237,7 @@ config SERIAL_CLPS711X_CONSOLE
 
 config SERIAL_SAMSUNG
 	tristate "Samsung SoC serial support"
-	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_APPLE || COMPILE_TEST
+	depends on PLAT_SAMSUNG || ARCH_S5PV210 || ARCH_EXYNOS || ARCH_APPLE || ARCH_ARTPEC || COMPILE_TEST
 	select SERIAL_CORE
 	help
 	  Support for the on-chip UARTs on the Samsung

drivers/tty/serial/samsung_tty.c

@@ -2825,6 +2825,36 @@ static const struct s3c24xx_serial_drv_data s5l_serial_drv_data = {
 #define S5L_SERIAL_DRV_DATA NULL
 #endif
 
+#if defined(CONFIG_ARCH_ARTPEC)
+static const struct s3c24xx_serial_drv_data artpec8_serial_drv_data = {
+	.info = {
+		.name		= "Axis ARTPEC-8 UART",
+		.type		= TYPE_S3C6400,
+		.port_type	= PORT_S3C6400,
+		.fifosize	= 64,
+		.has_divslot	= 1,
+		.rx_fifomask	= S5PV210_UFSTAT_RXMASK,
+		.rx_fifoshift	= S5PV210_UFSTAT_RXSHIFT,
+		.rx_fifofull	= S5PV210_UFSTAT_RXFULL,
+		.tx_fifofull	= S5PV210_UFSTAT_TXFULL,
+		.tx_fifomask	= S5PV210_UFSTAT_TXMASK,
+		.tx_fifoshift	= S5PV210_UFSTAT_TXSHIFT,
+		.def_clk_sel	= S3C2410_UCON_CLKSEL0,
+		.num_clks	= 1,
+		.clksel_mask	= 0,
+		.clksel_shift	= 0,
+	},
+	.def_cfg = {
+		.ucon		= S5PV210_UCON_DEFAULT,
+		.ufcon		= S5PV210_UFCON_DEFAULT,
+		.has_fracval	= 1,
+	}
+};
+#define ARTPEC8_SERIAL_DRV_DATA (&artpec8_serial_drv_data)
+#else
+#define ARTPEC8_SERIAL_DRV_DATA (NULL)
+#endif
+
 static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
 	{
 		.name		= "s3c2410-uart",
@@ -2853,6 +2883,9 @@ static const struct platform_device_id s3c24xx_serial_driver_ids[] = {
 	}, {
 		.name		= "exynos850-uart",
 		.driver_data	= (kernel_ulong_t)EXYNOS850_SERIAL_DRV_DATA,
+	}, {
+		.name		= "artpec8-uart",
+		.driver_data	= (kernel_ulong_t)ARTPEC8_SERIAL_DRV_DATA,
 	},
 	{ },
 };
@@ -2878,6 +2911,8 @@ static const struct of_device_id s3c24xx_uart_dt_match[] = {
 		.data = S5L_SERIAL_DRV_DATA },
 	{ .compatible = "samsung,exynos850-uart",
 		.data = EXYNOS850_SERIAL_DRV_DATA },
+	{ .compatible = "axis,artpec8-uart",
+		.data = ARTPEC8_SERIAL_DRV_DATA },
 	{},
 };
 MODULE_DEVICE_TABLE(of, s3c24xx_uart_dt_match);
@@ -3056,6 +3091,8 @@ OF_EARLYCON_DECLARE(s5pv210, "samsung,s5pv210-uart",
 			s5pv210_early_console_setup);
 OF_EARLYCON_DECLARE(exynos4210, "samsung,exynos4210-uart",
 			s5pv210_early_console_setup);
+OF_EARLYCON_DECLARE(artpec8, "axis,artpec8-uart",
+			s5pv210_early_console_setup);
 
 /* Apple S5L */
 static int __init apple_s5l_early_console_setup(struct earlycon_device *device,