This is a test patch that should not be merged to any of the published
Linux source tree.
1. The result of the UART dummy target device is as follows:
# udevadm monitor --kernel --environment > ~/uart.uevents
# echo add > /sys/bus/uart/uevent
# echo add > /sys/bus/uart/devices/DUMMY/uevent
# cat ~/uart.uevents
monitor will print the received events for:
KERNEL - the kernel uevent
KERNEL[252.443458] add /bus/uart (bus)
ACTION=add
DEVPATH=/bus/uart
SEQNUM=1142
SUBSYSTEM=bus
KERNEL[268.491709] add /devices/platform/serial8250/DUMMY (uart)
ACTION=add
DEVPATH=/devices/platform/serial8250/DUMMY
DEVTYPE=uart_device
MODALIAS=uart:DUMMY
SEQNUM=1144
SUBSYSTEM=uart
# cat /sys/bus/uart/devices/DUMMY/modalias
uart:DUMMY
# cat /sys/bus/uart/devices/DUMMY/tty_dev
ttyS3
# cat /sys/bus/uart/devices/DUMMY/tty_attrs
115200 8N1 HW SW
# cat /sys/bus/uart/devices/DUMMY/modem_lines
LE:RTS,
# ls -l /sys/bus/uart/devices/
DUMMY -> ../../../devices/platform/serial8250/DUMMY
# ls -l /sys/devices/platform/serial8250/DUMMY/
subsystem -> ../../../../bus/uart
host_node -> ../tty/ttyS3
# ls -l /sys/devices/platform/serial8250/tty/ttyS3/
target_node -> ../../DUMMY
2. The result of the UART customized DSDT target device is as follows:
The test is based on the following customized DSDT (containing the dummy
uart host adapter INTF000 and target device INTF001):
Device (UA00)
{
Name (_HID, "INTF000") // _HID: Hardware ID
Name (RBUF, ResourceTemplate ()
{
Memory32Fixed (ReadWrite,
0x00000000, // Address Base
0x00001000) // Address Length
})
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Return (RBUF)
}
Method (_STA, 0, NotSerialized) // _STA: Status
{
Return (0x0F)
}
Device (BTH0)
{
Name (_HID, "INTF001") // _HID: Hardware ID
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Name (UBUF, ResourceTemplate ()
{
UartSerialBus (0x0001C200, DataBitsEight, StopBitsOne,
0xC0, LittleEndian, ParityTypeNone, FlowControlHardware,
0x0020, 0x0020, "\\_SB.PCI0.UA00",
0x00, ResourceConsumer, ,
)
})
Return (UBUF)
}
Method (_STA, 0, NotSerialized) // _STA: Status
{
Return (0x0F)
}
}
}
# udevadm monitor --kernel --environment > ~/uart.uevents
# echo add > /sys/bus/uart/uevent
# echo add > /sys/bus/uart/devices/INTF001/uevent
# cat ~/uart.uevents
monitor will print the received events for:
KERNEL - the kernel uevent
KERNEL[252.443458] add /bus/uart (bus)
ACTION=add
DEVPATH=/bus/uart
SEQNUM=1142
SUBSYSTEM=bus
KERNEL[268.491709] add /devices/platform/INTF000:00/INTF001:00 (uart)
ACTION=add
DEVPATH=/devices/platform/INTF000:00/INTF001:00
DEVTYPE=uart_device
MODALIAS=uart:INTF001:00
SEQNUM=1144
SUBSYSTEM=uart
# cat /sys/bus/uart/devices/INTF001:00/modalias
uart:INTF001:00
# cat /sys/bus/uart/devices/INTF001:00/tty_dev
ttyS0
# cat /sys/bus/uart/devices/INTF001:00/tty_attrs
115200 8N0 HW
# cat /sys/bus/uart/devices/INTF001:00/modem_lines
LE:RTS,CTS,
# ls -l /sys/bus/uart/devices/
INTF001:00 -> ../../../devices/platform/INTF000:00/INTF001:00
# ls -l /sys/devices/platform/INTF000:00/INTF001:00/
firmware_node -> ../../../LNXSYSTM:00/device:00/INTF000:00/INTF001:00
subsystem -> ../../../../bus/uart
host_node -> ../tty/ttyS0
# ls -l /sys/devices/platform/INTF000:00/tty/ttyS0/
target_node -> ../../INTF001:00
# ls -l /sys/bus/acpi/INTF001:00/
physical_node -> ../../../../pnp0/00:00
physical_node1 -> ../../../../platform/INTF000:00/INTF001:00
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
---
drivers/acpi/scan.c | 1 +
drivers/tty/serial/8250/8250.c | 12 ++++
drivers/tty/serial/8250/8250_dummy.c | 129 ++++++++++++++++++++++++++++++++++
drivers/tty/serial/8250/Kconfig | 10 +++
drivers/tty/serial/8250/Makefile | 1 +
drivers/tty/serial/serial_bus.c | 17 +++++
include/linux/serial_bus.h | 5 ++
7 files changed, 175 insertions(+)
create mode 100644 drivers/tty/serial/8250/8250_dummy.c
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 4dd13e4..95c7528 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -36,6 +36,7 @@ static const char *dummy_hid = "device";
static const struct acpi_device_id acpi_platform_device_ids[] = {
{ "PNP0D40" },
+ { "INTF000" },
{ }
};
diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index af78374..745e05d 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -35,6 +35,7 @@
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
+#include <linux/serial_bus.h>
#include <linux/nmi.h>
#include <linux/mutex.h>
#include <linux/slab.h>
@@ -2986,6 +2987,8 @@ void serial8250_resume_port(int line)
uart_resume_port(&serial8250_reg, port);
}
+struct uart_device *uart_dummy;
+
/*
* Register a set of serial devices attached to a platform device. The
* list is terminated with a zero flags entry, which means we expect
@@ -2996,6 +2999,7 @@ static int __devinit serial8250_probe(struct platform_device *dev)
struct plat_serial8250_port *p = dev->dev.platform_data;
struct uart_8250_port uart;
int ret, i, irqflag = 0;
+ unsigned int dummy_line;
memset(&uart, 0, sizeof(uart));
@@ -3031,6 +3035,13 @@ static int __devinit serial8250_probe(struct platform_device *dev)
p->irq, ret);
}
}
+
+ dummy_line = serial8250_ports[nr_uarts-1].port.line;
+ pr_info("registering DUMMY at line %d.\n", dummy_line);
+ uart_dummy = uart_register_dummy(&dev->dev,
+ serial8250_reg.tty_driver,
+ dummy_line);
+
return 0;
}
@@ -3041,6 +3052,7 @@ static int __devexit serial8250_remove(struct platform_device *dev)
{
int i;
+ uart_unregister_device(uart_dummy);
for (i = 0; i < nr_uarts; i++) {
struct uart_8250_port *up = &serial8250_ports[i];
diff --git a/drivers/tty/serial/8250/8250_dummy.c b/drivers/tty/serial/8250/8250_dummy.c
new file mode 100644
index 0000000..c5ec064
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dummy.c
@@ -0,0 +1,129 @@
+/*
+ * 8250_dummy.c: Dummy 8250 UART target device enumerator
+ *
+ * Copyright (c) 2012, Intel Corporation
+ * Author: Lv Zheng <lv.zheng@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_bus.h>
+#include <linux/acpi.h>
+#include <linux/acpi_uart.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+struct dummy8250_data {
+ int last_lcr;
+ int line;
+};
+
+static void dummy8250_serial_out(struct uart_port *p, int offset, int value)
+{
+}
+
+static unsigned int dummy8250_serial_in(struct uart_port *p, int offset)
+{
+ return 0;
+}
+
+struct klist *dummy8250_mgr;
+int dummy8250_num;
+
+static int __devinit dummy8250_probe(struct platform_device *pdev)
+{
+ struct uart_8250_port uart = {};
+ struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ struct dummy8250_data *data;
+#ifdef CONFIG_ACPI_UART
+ struct klist *mgr;
+#endif
+
+ dev_info(&pdev->dev, "1\n");
+ if (!regs) {
+ dev_err(&pdev->dev, "no registers defined\n");
+ return -EINVAL;
+ }
+
+ dev_info(&pdev->dev, "2\n");
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ uart.port.private_data = data;
+
+ spin_lock_init(&uart.port.lock);
+ uart.port.mapbase = regs->start;
+ uart.port.type = PORT_8250;
+ uart.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP |
+ UPF_FIXED_PORT | UPF_FIXED_TYPE;
+ uart.port.dev = &pdev->dev;
+
+ uart.port.iotype = UPIO_MEM;
+ uart.port.serial_in = dummy8250_serial_in;
+ uart.port.serial_out = dummy8250_serial_out;
+ uart.port.uartclk = 40000000;
+
+ dev_info(&pdev->dev, "3\n");
+ data->line = serial8250_register_8250_port(&uart);
+ if (data->line < 0)
+ return data->line;
+
+#ifdef CONFIG_ACPI_UART
+ dev_info(&pdev->dev, "4\n");
+ mgr = acpi_uart_register_devices(dummy8250_mgr,
+ &pdev->dev,
+ serial8250_reg.tty_driver,
+ data->line);
+ if (mgr) {
+ dummy8250_mgr = mgr;
+ dummy8250_num++;
+ }
+#endif
+ dev_info(&pdev->dev, "5\n");
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static int __devexit dummy8250_remove(struct platform_device *pdev)
+{
+ struct dummy8250_data *data = platform_get_drvdata(pdev);
+
+#ifdef CONFIG_ACPI_UART
+ dummy8250_num--;
+ if (!dummy8250_num)
+ acpi_uart_unregister_devices(dummy8250_mgr);
+#endif
+ serial8250_unregister_port(data->line);
+
+ return 0;
+}
+
+static const struct acpi_device_id dummy8250_match[] = {
+ { .id = "INTF000" },
+ { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, dummy8250_match);
+
+static struct platform_driver dummy8250_platform_driver = {
+ .driver = {
+ .name = "dummy-uart",
+ .owner = THIS_MODULE,
+ .acpi_match_table = dummy8250_match,
+ },
+ .probe = dummy8250_probe,
+ .remove = __devexit_p(dummy8250_remove),
+};
+
+module_platform_driver(dummy8250_platform_driver);
+
+MODULE_AUTHOR("Lv Zheng");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Dummy 8250 serial port driver");
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index f3d283f..3ba480a 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -270,6 +270,16 @@ config SERIAL_8250_DW
Selecting this option will enable handling of the extra features
present in the Synopsys DesignWare APB UART.
+config SERIAL_8250_DUMMY
+ tristate "Support for dummy ACPI 8250"
+ depends on SERIAL_8250 && ACPI
+ help
+ Selecting this option will enable a test UART target device DUMMY
+ under the ISA serial8250 and a test UART host adapter INTF000
+ as an platform device for the purpose of testing the ACPI UART
+ enumeration support.
+ If unsure, say "N" here.
+
config SERIAL_8250_EM
tristate "Support for Emma Mobile intergrated serial port"
depends on SERIAL_8250 && ARM && HAVE_CLK
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 108fe7f..fb82aa9 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -19,3 +19,4 @@ obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o
obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o
obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o
+obj-$(CONFIG_SERIAL_8250_DUMMY) += 8250_dummy.o
diff --git a/drivers/tty/serial/serial_bus.c b/drivers/tty/serial/serial_bus.c
index 66c112d..033dd37 100644
--- a/drivers/tty/serial/serial_bus.c
+++ b/drivers/tty/serial/serial_bus.c
@@ -393,6 +393,23 @@ void uart_del_adapter(struct klist *adap)
}
EXPORT_SYMBOL_GPL(uart_del_adapter);
+static struct uart_board_info dummy_target = {
+ .type = "DUMMY",
+ .baud = 115200,
+ .cflag = CS8 | CSTOPB | CRTSCTS,
+ .iflag = (IXON | IXOFF),
+ .mctrl = TIOCM_LE | TIOCM_RTS,
+};
+
+struct uart_device *uart_register_dummy(struct device *dev,
+ struct tty_driver *drv,
+ unsigned int line)
+{
+ dummy_target.line = line;
+ return uart_register_device(NULL, dev, drv, &dummy_target);
+}
+EXPORT_SYMBOL_GPL(uart_register_dummy);
+
struct bus_type uart_bus_type = {
.name = "uart",
};
diff --git a/include/linux/serial_bus.h b/include/linux/serial_bus.h
index 1955d3e..7eb74b9 100644
--- a/include/linux/serial_bus.h
+++ b/include/linux/serial_bus.h
@@ -118,4 +118,9 @@ struct device *uart_tty_find(struct tty_driver *drv, unsigned int line,
struct device *dev);
void uart_tty_name(struct tty_driver *driver, unsigned int line, char *p);
+/* Test dummy device registration */
+struct uart_device *uart_register_dummy(struct device *dev,
+ struct tty_driver *drv,
+ unsigned int line);
+
#endif /* LINUX_SERIAL_BUS_H */
--
1.7.10
--
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