From 00bbbae41d304ad183fbba1be44a118056370956 Mon Sep 17 00:00:00 2001
From: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Date: Thu, 17 May 2018 17:46:52 +0200
Subject: [PATCH] drivers/serial: Add port 2 instance in ns16550 driver

Looks lik ARC arch snps_esmk can provide a 3rd port of this controller,
so let's add the necessary bits and pieces to get it instanciated if one
enable this port in DTS.

PCI settings are not introduced for that port as there is no known
arch/board exposing a 3rd port on PCI bus.

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
---
 drivers/serial/Kconfig.ns16550 | 25 +++++++++++++++++++
 drivers/serial/uart_ns16550.c  | 44 ++++++++++++++++++++++++++++++++++
 2 files changed, 69 insertions(+)

diff --git a/drivers/serial/Kconfig.ns16550 b/drivers/serial/Kconfig.ns16550
index fffb0ef5ec..81d7c45a7f 100644
--- a/drivers/serial/Kconfig.ns16550
+++ b/drivers/serial/Kconfig.ns16550
@@ -164,3 +164,28 @@ config UART_NS16550_PORT_1_DLF
 	depends on UART_NS16550_PORT_1 && UART_NS16550_DLF
 	help
 	  Value for DLF register.
+
+# ---------- Port 2 ----------
+
+menuconfig UART_NS16550_PORT_2
+	bool "Enable NS16550 Port 2"
+	default n
+	depends on UART_NS16550
+	help
+	  This tells the driver to configure the UART port at boot, depending on
+	  the additional configure options below.
+
+
+config UART_NS16550_PORT_2_OPTIONS
+	int "Port 2 Options"
+	default 0
+	depends on UART_NS16550_PORT_2
+	help
+	  Options used for port initialization.
+
+config UART_NS16550_PORT_2_DLF
+	hex "Port 2 DLF value"
+	default 0x0
+	depends on UART_NS16550_PORT_2 && UART_NS16550_DLF
+	help
+	  Value for DLF register.
diff --git a/drivers/serial/uart_ns16550.c b/drivers/serial/uart_ns16550.c
index 41088ad43c..5998b8905a 100644
--- a/drivers/serial/uart_ns16550.c
+++ b/drivers/serial/uart_ns16550.c
@@ -850,3 +850,47 @@ static void irq_config_func_1(struct device *dev)
 #endif
 
 #endif /* CONFIG_UART_NS16550_PORT_1 */
+
+#ifdef CONFIG_UART_NS16550_PORT_2
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+static void irq_config_func_2(struct device *port);
+#endif
+
+static const struct uart_ns16550_device_config uart_ns16550_dev_cfg_2 = {
+	.sys_clk_freq = CONFIG_UART_NS16550_PORT_2_CLK_FREQ,
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+	.irq_config_func = irq_config_func_2,
+#endif
+};
+
+static struct uart_ns16550_dev_data_t uart_ns16550_dev_data_2 = {
+	.port = CONFIG_UART_NS16550_PORT_2_BASE_ADDR,
+	.baud_rate = CONFIG_UART_NS16550_PORT_2_BAUD_RATE,
+	.options = CONFIG_UART_NS16550_PORT_2_OPTIONS,
+
+#ifdef CONFIG_UART_NS16550_PORT_2_DLF
+	.dlf = CONFIG_UART_NS16550_PORT_2_DLF,
+#endif
+};
+
+DEVICE_AND_API_INIT(uart_ns16550_2, CONFIG_UART_NS16550_PORT_2_NAME, &uart_ns16550_init,
+		    &uart_ns16550_dev_data_2, &uart_ns16550_dev_cfg_2,
+		    PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
+		    &uart_ns16550_driver_api);
+
+#ifdef CONFIG_UART_INTERRUPT_DRIVEN
+static void irq_config_func_2(struct device *dev)
+{
+	ARG_UNUSED(dev);
+
+	IRQ_CONNECT(CONFIG_UART_NS16550_PORT_2_IRQ,
+		    CONFIG_UART_NS16550_PORT_2_IRQ_PRI,
+		    uart_ns16550_isr, DEVICE_GET(uart_ns16550_2),
+		    CONFIG_UART_NS16550_PORT_2_IRQ_FLAGS);
+	irq_enable(CONFIG_UART_NS16550_PORT_2_IRQ);
+}
+#endif
+
+#endif /* CONFIG_UART_NS16550_PORT_2 */