mfd: ioc3: Add driver for SGI IOC3 chip

SGI IOC3 chip has integrated ethernet, keyboard and mouse interface.
It also supports connecting a SuperIO chip for serial and parallel
interfaces. IOC3 is used inside various SGI systemboards and add-on
cards with different equipped external interfaces.

Support for ethernet and serial interfaces were implemented inside
the network driver. This patchset moves out the not network related
parts to a new MFD driver, which takes care of card detection,
setup of platform devices and interrupt distribution for the subdevices.

Serial portion: Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>
Network part: Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Network part: Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-serial@vger.kernel.org

arch/mips/sgi-ip27/ip27-timer.c

@@ -168,23 +168,3 @@ void hub_rtc_init(nasid_t nasid)
 		LOCAL_HUB_S(PI_RT_PEND_B, 0);
 	}
 }
-
-static int __init sgi_ip27_rtc_devinit(void)
-{
-	struct resource res;
-
-	memset(&res, 0, sizeof(res));
-	res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
-			      IOC3_BYTEBUS_DEV0);
-	res.end = res.start + 32767;
-	res.flags = IORESOURCE_MEM;
-
-	return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
-						      &res, 1));
-}
-
-/*
- * kludge make this a device_initcall after ioc3 resource conflicts
- * are resolved
- */
-late_initcall(sgi_ip27_rtc_devinit);

drivers/mfd/Kconfig

@@ -2004,5 +2004,18 @@ config RAVE_SP_CORE
 	  Select this to get support for the Supervisory Processor
 	  device found on several devices in RAVE line of hardware.
 
+config SGI_MFD_IOC3
+	tristate "SGI IOC3 core driver"
+	depends on PCI && MIPS && 64BIT
+	select MFD_CORE
+	help
+	  This option enables basic support for the SGI IOC3-based
+	  controller cards.  This option does not enable any specific
+	  functions on such a card, but provides necessary infrastructure
+	  for other drivers to utilize.
+
+	  If you have an SGI Origin, Octane, or a PCI IOC3 card,
+	  then say Y. Otherwise say N.
+
 endmenu
 endif

drivers/mfd/Makefile

@@ -255,3 +255,4 @@ obj-$(CONFIG_MFD_ROHM_BD70528)	+= rohm-bd70528.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
 obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 
+obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o

drivers/net/ethernet/sgi/Kconfig

@@ -6,7 +6,7 @@
 config NET_VENDOR_SGI
 	bool "SGI devices"
 	default y
-	depends on (PCI && SGI_IP27) || SGI_IP32
+	depends on (PCI && SGI_MFD_IOC3) ||  SGI_IP32
 	---help---
 	  If you have a network (Ethernet) card belonging to this class, say Y.
 
@@ -19,7 +19,8 @@ if NET_VENDOR_SGI
 
 config SGI_IOC3_ETH
 	bool "SGI IOC3 Ethernet"
-	depends on PCI && SGI_IP27
+	depends on PCI && SGI_MFD_IOC3
+	select CRC16
 	select CRC32
 	select MII
 	---help---

drivers/tty/serial/8250/8250_ioc3.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SGI IOC3 8250 UART driver
+ *
+ * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
+ *
+ * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
+ *               Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org>
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+
+#include "8250.h"
+
+#define IOC3_UARTCLK (22000000 / 3)
+
+struct ioc3_8250_data {
+	int line;
+};
+
+static unsigned int ioc3_serial_in(struct uart_port *p, int offset)
+{
+	return readb(p->membase + (offset ^ 3));
+}
+
+static void ioc3_serial_out(struct uart_port *p, int offset, int value)
+{
+	writeb(value, p->membase + (offset ^ 3));
+}
+
+static int serial8250_ioc3_probe(struct platform_device *pdev)
+{
+	struct ioc3_8250_data *data;
+	struct uart_8250_port up;
+	struct resource *r;
+	void __iomem *membase;
+	int irq, line;
+
+	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!r)
+		return -ENODEV;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	membase = devm_ioremap_nocache(&pdev->dev, r->start, resource_size(r));
+	if (!membase)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		irq = 0; /* no interrupt -> use polling */
+
+	/* Register serial ports with 8250.c */
+	memset(&up, 0, sizeof(struct uart_8250_port));
+	up.port.iotype = UPIO_MEM;
+	up.port.uartclk = IOC3_UARTCLK;
+	up.port.type = PORT_16550A;
+	up.port.irq = irq;
+	up.port.flags = (UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ);
+	up.port.dev = &pdev->dev;
+	up.port.membase = membase;
+	up.port.mapbase = r->start;
+	up.port.serial_in = ioc3_serial_in;
+	up.port.serial_out = ioc3_serial_out;
+	line = serial8250_register_8250_port(&up);
+	if (line < 0)
+		return line;
+
+	platform_set_drvdata(pdev, data);
+	return 0;
+}
+
+static int serial8250_ioc3_remove(struct platform_device *pdev)
+{
+	struct ioc3_8250_data *data = platform_get_drvdata(pdev);
+
+	serial8250_unregister_port(data->line);
+	return 0;
+}
+
+static struct platform_driver serial8250_ioc3_driver = {
+	.probe  = serial8250_ioc3_probe,
+	.remove = serial8250_ioc3_remove,
+	.driver = {
+		.name = "ioc3-serial8250",
+	}
+};
+
+module_platform_driver(serial8250_ioc3_driver);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
+MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");
+MODULE_LICENSE("GPL");

drivers/tty/serial/8250/Kconfig

@@ -371,6 +371,17 @@ config SERIAL_8250_EM
 	  port hardware found on the Emma Mobile line of processors.
 	  If unsure, say N.
 
+config SERIAL_8250_IOC3
+	tristate "SGI IOC3 8250 UART support"
+	depends on SGI_MFD_IOC3 && SERIAL_8250
+	select SERIAL_8250_EXTENDED
+	select SERIAL_8250_SHARE_IRQ
+	help
+	  Enable this if you have a SGI Origin or Octane machine. This module
+	  provides basic serial support by directly driving the UART chip
+	  behind the IOC3 device on those systems.  Maximum baud speed is
+	  38400bps using this driver.
+
 config SERIAL_8250_RT288X
 	bool "Ralink RT288x/RT305x/RT3662/RT3883 serial port support"
 	depends on SERIAL_8250

drivers/tty/serial/8250/Makefile

@@ -28,6 +28,7 @@ obj-$(CONFIG_SERIAL_8250_FSL)		+= 8250_fsl.o
 obj-$(CONFIG_SERIAL_8250_MEN_MCB)	+= 8250_men_mcb.o
 obj-$(CONFIG_SERIAL_8250_DW)		+= 8250_dw.o
 obj-$(CONFIG_SERIAL_8250_EM)		+= 8250_em.o
+obj-$(CONFIG_SERIAL_8250_IOC3)		+= 8250_ioc3.o
 obj-$(CONFIG_SERIAL_8250_OMAP)		+= 8250_omap.o
 obj-$(CONFIG_SERIAL_8250_LPC18XX)	+= 8250_lpc18xx.o
 obj-$(CONFIG_SERIAL_8250_MT6577)	+= 8250_mtk.o