This patch adds 8250 IOC3 platform driver for serial ports connected via
a SuperIO chip to a SGI IOC3 chip.
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
---
drivers/tty/serial/8250/8250_ioc3.c | 98 +++++++++++++++++++++++++++++++++++++
drivers/tty/serial/8250/Kconfig | 11 +++++
drivers/tty/serial/8250/Makefile | 1 +
3 files changed, 110 insertions(+)
create mode 100644 drivers/tty/serial/8250/8250_ioc3.c
diff --git a/drivers/tty/serial/8250/8250_ioc3.c b/drivers/tty/serial/8250/8250_ioc3.c
new file mode 100644
index 000000000000..4c405f1b9c67
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_ioc3.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SGI IOC3 8250 UART driver
+ *
+ * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
+ *
+ * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@xxxxxxxxxxxxx>
+ * Copyright (C) 2014 Joshua Kinard <kumba@xxxxxxxxxx>
+ */
+
+#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@xxxxxxx>");
+MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 15c2c5463835..9d24615aabfb 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -364,6 +364,17 @@ 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
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 18751bc63a84..79f74b4d57e5 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -27,6 +27,7 @@ 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
--
2.13.7
