On Wed, Apr 03, 2013 at 10:05:49AM +0800, Lv Zheng wrote:
> ACPI 5.0 specification introduces mechanisms of enumerating the peripherals
> connected on the serial buses. It will look like:
> Device (BTH0)
> {
> Name (_HID, "IBMF001") // _HID: Hardware ID
> Name (_CID, "PNPF001") // _CID: Compatible 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)
> }
> }
> This patch follows the specification, implementing such UART enumeration
> machanism by exporting current peripheral HID/CIDs for the UART devices.
> A userspace udev rule may look like:
> SUBSYSTEM=tty, ATTR{peripheral_type}=="*:IBMF001:*",
> RUN+="/bin/userprog --devpath=%p"
> Thanks for the internal composers:
> Mika Westerberg <mika.westerberg@xxxxxxxxx>
> Huang Ying <ying.huang@xxxxxxxxx>
> Zhang Rui <rui.zhang@xxxxxxxxx>
> Thanks for the internal reviewers:
> Alan Cox <alan@xxxxxxxxxxxxxxx>
> Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Heikki Krogerus <heikki.krogerus@xxxxxxxxx>
> Andriy Shevchenko <andriy.shevchenko@xxxxxxxxx>
> Fengguang Wu <fengguang.wu@xxxxxxxxx>
Why are these names not on the list below?
> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> Acked-by: Huang Ying <ying.huang@xxxxxxxxx>
> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> drivers/acpi/Kconfig | 6 ++
> drivers/acpi/Makefile | 1 +
> drivers/acpi/acpi_uart.c | 135 ++++++++++++++++++++++++++++++++++++++
> drivers/acpi/internal.h | 2 +
> drivers/acpi/scan.c | 8 +--
> drivers/tty/serial/serial_core.c | 15 +++++
> include/linux/tty.h | 11 ++++
> 7 files changed, 174 insertions(+), 4 deletions(-)
> create mode 100644 drivers/acpi/acpi_uart.c
>
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 92ed969..42233f6 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -186,6 +186,12 @@ config ACPI_I2C
> help
> ACPI I2C enumeration support.
>
> +config ACPI_UART
> + def_tristate TTY
> + depends on TTY
> + help
> + ACPI UART enumeration support.
Please provide more information here.
As this is primarily an ACPI patch, I need an ack from a ACPI maintainer
before I can take this.
> +
> config ACPI_PROCESSOR
> tristate "Processor"
> select THERMAL
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 474fcfe..4db5470 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -72,6 +72,7 @@ obj-$(CONFIG_ACPI_EC_DEBUGFS) += ec_sys.o
> obj-$(CONFIG_ACPI_CUSTOM_METHOD)+= custom_method.o
> obj-$(CONFIG_ACPI_BGRT) += bgrt.o
> obj-$(CONFIG_ACPI_I2C) += acpi_i2c.o
> +obj-$(CONFIG_ACPI_UART) += acpi_uart.o
>
> # processor has its own "processor." module_param namespace
> processor-y := processor_driver.o processor_throttling.o
> diff --git a/drivers/acpi/acpi_uart.c b/drivers/acpi/acpi_uart.c
> new file mode 100644
> index 0000000..dd5ac2e
> --- /dev/null
> +++ b/drivers/acpi/acpi_uart.c
> @@ -0,0 +1,135 @@
> +/*
> + * acpi_uart.c - ACPI UART enumeration support
> + *
> + * Copyright (c) 2013, 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/init.h>
> +#include <linux/tty.h>
> +#include <linux/module.h>
> +#include <linux/acpi.h>
> +
> +#include "internal.h"
> +
> +struct acpi_uart_buf {
> + char *buf;
> + size_t size;
> + int *len;
> +};
> +
> +struct acpi_uart_enum {
> + void *context;
> + acpi_status status;
> +
> + struct acpi_device *adev;
> +};
> +
> +static acpi_status
> +acpi_uart_enum_pnpids(struct acpi_device *adev,
> + struct acpi_resource_uart_serialbus *sb,
> + void *context);
> +
> +static int acpi_uart_enum_resources(struct acpi_resource *ares,
> + void *context)
> +{
> + struct acpi_uart_enum *ctx = context;
> + struct acpi_resource_uart_serialbus *sb;
> +
> + if (ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS)
> + return 1;
> + sb = &ares->data.uart_serial_bus;
> + if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_UART)
> + return 1;
> +
> + ctx->status = acpi_uart_enum_pnpids(ctx->adev, sb, ctx->context);
> + return 1;
> +}
> +
> +static acpi_status acpi_uart_enum_devices(acpi_handle handle, u32 level,
> + void *context,
> + void **return_value)
> +{
> + struct acpi_uart_enum *ctx = context;
> + struct acpi_device *adev;
> + struct list_head resource_list;
> +
> + if (acpi_bus_get_device(handle, &adev))
> + return AE_OK;
> + if (acpi_bus_get_status(adev) || !adev->status.present)
> + return AE_OK;
> +
> + /* Enumerate resources. */
> + ctx->adev = adev;
> + ctx->status = AE_OK;
> + INIT_LIST_HEAD(&resource_list);
> + acpi_dev_get_resources(adev, &resource_list,
> + acpi_uart_enum_resources, ctx);
> + acpi_dev_free_resource_list(&resource_list);
> +
> + return ctx->status;
> +}
> +
> +static int acpi_uart_walk_port(struct device *parent,
> + void *context)
> +{
> + acpi_handle handle;
> + acpi_status status;
> + struct acpi_uart_enum ctx;
> +
> + handle = parent ? ACPI_HANDLE(parent) : NULL;
> + if (!handle)
> + return -ENODEV;
> +
> + ctx.context = context;
> +
> + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
> + acpi_uart_enum_devices, NULL,
> + &ctx, NULL);
> + if (ACPI_FAILURE(status))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static acpi_status
> +acpi_uart_enum_pnpids(struct acpi_device *adev,
> + struct acpi_resource_uart_serialbus *sb,
> + void *context)
> +{
> + int len;
> + struct acpi_uart_buf *ctx = context;
> +
> + len = acpi_device_create_modalias(adev, ctx->buf, ctx->size);
> + *ctx->len = len;
> +
> + return len < 0 ? AE_CTRL_DEPTH : AE_OK;
> +}
> +
> +/**
> + * acpi_uart_get_peripheral_type - get peripheral HID/CIDs
> + * @dev: the tty class device
> + * @buf: the string buffer containing HID/CIDs
> + * @size: the size of the string buffer
> + *
> + * Obtain UART peripheral HID/CIDs. Return buffer size on success,
> + * -errno on failure.
> + */
> +int acpi_uart_get_peripheral_type(struct device *dev,
> + char *buf, size_t size)
> +{
> + int ret;
> + int len = 0;
> + struct acpi_uart_buf ctx = { buf, size, &len };
> +
> + ret = acpi_uart_walk_port(dev->parent, &ctx);
> + if (ret < 0)
> + return ret;
> +
> + return len;
> +}
> +EXPORT_SYMBOL_GPL(acpi_uart_get_peripheral_type);
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index 3c94a73..30d7440 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -61,6 +61,8 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
> int type, unsigned long long sta);
> void acpi_device_add_finalize(struct acpi_device *device);
> void acpi_free_ids(struct acpi_device *device);
> +int acpi_device_create_modalias(struct acpi_device *acpi_dev,
> + char *modalias, int size);
>
> /* --------------------------------------------------------------------------
> Power Resource
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 5e7e991..0d7d49f 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -68,8 +68,8 @@ int acpi_scan_add_handler(struct acpi_scan_handler *handler)
> * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
> * char *modalias: "acpi:IBM0001:ACPI0001"
> */
> -static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
> - int size)
> +int acpi_device_create_modalias(struct acpi_device *acpi_dev,
> + char *modalias, int size)
> {
> int len;
> int count;
> @@ -99,7 +99,7 @@ acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, cha
> int len;
>
> /* Device has no HID and no CID or string is >1024 */
> - len = create_modalias(acpi_dev, buf, 1024);
> + len = acpi_device_create_modalias(acpi_dev, buf, 1024);
> if (len <= 0)
> return 0;
> buf[len++] = '\n';
> @@ -567,7 +567,7 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
>
> if (add_uevent_var(env, "MODALIAS="))
> return -ENOMEM;
> - len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
> + len = acpi_device_create_modalias(acpi_dev, &env->buf[env->buflen - 1],
> sizeof(env->buf) - env->buflen);
> if (len >= (sizeof(env->buf) - env->buflen))
> return -ENOMEM;
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index a400002..17e104e 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -2515,6 +2515,19 @@ static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev,
> return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift);
> }
>
> +static ssize_t uart_get_attr_peripheral_type(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + int len;
> +
> + len = acpi_uart_get_peripheral_type(dev, buf, 1024);
> + if (len > 0) {
> + buf[len++] = '\n';
> + return len;
> + }
> + return snprintf(buf, PAGE_SIZE, "uart\n");
What is the "uart" part for? Isn't that kind of obvious?
> +}
You are creating a new sysfs file, you must create a new
Documentation/ABI entry as well.
> +
> static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL);
> static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL);
> static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL);
> @@ -2528,6 +2541,7 @@ static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divis
> static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL);
> static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL);
> static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL);
> +static DEVICE_ATTR(peripheral_type, S_IRUSR | S_IRGRP, uart_get_attr_peripheral_type, NULL);
>
> static struct attribute *tty_dev_attrs[] = {
> &dev_attr_type.attr,
> @@ -2543,6 +2557,7 @@ static struct attribute *tty_dev_attrs[] = {
> &dev_attr_io_type.attr,
> &dev_attr_iomem_base.attr,
> &dev_attr_iomem_reg_shift.attr,
> + &dev_attr_peripheral_type.attr,
> NULL,
> };
>
> diff --git a/include/linux/tty.h b/include/linux/tty.h
> index 367a9df..723fdd01 100644
> --- a/include/linux/tty.h
> +++ b/include/linux/tty.h
> @@ -692,4 +692,15 @@ do { \
> } while (0)
>
>
> +#ifdef CONFIG_ACPI_UART
> +int acpi_uart_get_peripheral_type(struct device *dev,
> + char *buf, size_t size);
> +#else
> +static inline int acpi_uart_get_peripheral_type(struct device *dev,
> + char *buf, size_t size)
> +{
> + return -ENODEV;
> +}
> +#endif
I see you never tested this code without the configuration option
enabled :(
{sigh}
greg k-h
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