serial, mfd: don't hardcode the console

Add support to specify which HSU port to use as an early console. This can
be selected by passing "earlyprintk=hsu<n>" on the kernel command line. By
default port 0 is still used.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/include/asm/mrst.h

@@ -51,7 +51,7 @@ extern struct console early_mrst_console;
 extern void mrst_early_console_init(void);
 
 extern struct console early_hsu_console;
-extern void hsu_early_console_init(void);
+extern void hsu_early_console_init(const char *);
 
 extern void intel_scu_devices_create(void);
 extern void intel_scu_devices_destroy(void);

arch/x86/kernel/early_printk.c

@@ -247,7 +247,7 @@ static int __init setup_early_printk(char *buf)
 		}
 
 		if (!strncmp(buf, "hsu", 3)) {
-			hsu_early_console_init();
+			hsu_early_console_init(buf + 3);
 			early_console_register(&early_hsu_console, keep);
 		}
 #endif

arch/x86/platform/mrst/early_printk_mrst.c

@@ -245,16 +245,24 @@ struct console early_mrst_console = {
  * Following is the early console based on Medfield HSU (High
  * Speed UART) device.
  */
-#define HSU_PORT2_PADDR		0xffa28180
+#define HSU_PORT_BASE		0xffa28080
 
 static void __iomem *phsu;
 
-void hsu_early_console_init(void)
+void hsu_early_console_init(const char *s)
 {
+	unsigned long paddr, port = 0;
 	u8 lcr;
 
-	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-							HSU_PORT2_PADDR);
+	/*
+	 * Select the early HSU console port if specified by user in the
+	 * kernel command line.
+	 */
+	if (*s && !kstrtoul(s, 10, &port))
+		port = clamp_val(port, 0, 2);
+
+	paddr = HSU_PORT_BASE + port * 0x80;
+	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
 
 	/* Disable FIFO */
 	writeb(0x0, phsu + UART_FCR);

drivers/tty/serial/mfd.c

@@ -1156,7 +1156,6 @@ serial_hsu_console_setup(struct console *co, char *options)
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';
-	int ret;
 
 	if (co->index == -1 || co->index >= serial_hsu_reg.nr)
 		co->index = 0;
@@ -1167,9 +1166,7 @@ serial_hsu_console_setup(struct console *co, char *options)
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 
-	ret = uart_set_options(&up->port, co, baud, parity, bits, flow);
-
-	return ret;
+	return uart_set_options(&up->port, co, baud, parity, bits, flow);
 }
 
 static struct console serial_hsu_console = {
@@ -1178,9 +1175,13 @@ static struct console serial_hsu_console = {
 	.device		= uart_console_device,
 	.setup		= serial_hsu_console_setup,
 	.flags		= CON_PRINTBUFFER,
-	.index		= 2,
+	.index		= -1,
 	.data		= &serial_hsu_reg,
 };
+
+#define SERIAL_HSU_CONSOLE	(&serial_hsu_console)
+#else
+#define SERIAL_HSU_CONSOLE	NULL
 #endif
 
 struct uart_ops serial_hsu_pops = {
@@ -1210,6 +1211,7 @@ static struct uart_driver serial_hsu_reg = {
 	.major		= TTY_MAJOR,
 	.minor		= 128,
 	.nr		= 3,
+	.cons		= SERIAL_HSU_CONSOLE,
 };
 
 #ifdef CONFIG_PM
@@ -1344,12 +1346,6 @@ static int serial_hsu_probe(struct pci_dev *pdev,
 		}
 		uart_add_one_port(&serial_hsu_reg, &uport->port);
 
-#ifdef CONFIG_SERIAL_MFD_HSU_CONSOLE
-		if (index == 2) {
-			register_console(&serial_hsu_console);
-			uport->port.cons = &serial_hsu_console;
-		}
-#endif
 		pci_set_drvdata(pdev, uport);
 	}