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    Subject[PATCH v3 2/8] mfd / platform: cros_ec: move lightbar attributes to its own driver.
    Date
    The entire way how cros sysfs attibutes are created is broken.
    cros_ec_lightbar should be its own driver and its attributes should be
    associated with a lightbar driver not the mfd driver. In order to retain
    the path, the lightbar attributes are attached to the cros_class.

    The patch also adds the sysfs documentation.

    Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
    ---

    Changes in v3:
    - Removed unneded check for ec_dev.

    Changes in v2:
    - Removed the two exported functions to attach/detach to the cros_class.
    - Use dev_warn instead of dev_err when adding the lightbar.

    ...sfs-class-chromeos-driver-cros-ec-lightbar | 74 +++++++++++++++
    drivers/mfd/cros_ec_dev.c | 24 ++---
    drivers/mfd/cros_ec_dev.h | 6 --
    drivers/platform/chrome/Kconfig | 10 ++
    drivers/platform/chrome/Makefile | 3 +-
    drivers/platform/chrome/cros_ec_lightbar.c | 95 ++++++++++++++-----
    include/linux/mfd/cros_ec.h | 1 -
    7 files changed, 172 insertions(+), 41 deletions(-)
    create mode 100644 Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar

    diff --git a/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar b/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar
    new file mode 100644
    index 000000000000..4893fd2e956f
    --- /dev/null
    +++ b/Documentation/ABI/testing/sysfs-class-chromeos-driver-cros-ec-lightbar
    @@ -0,0 +1,74 @@
    +What: /sys/class/chromeos/<cros-ec>/lightbar/brightness
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + Writing to this file adjusts the overall brightness of
    + the lightbar, separate from any color intensity. The
    + valid range is 0 (off) to 255 (maximum brightness).
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/interval_msec
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + The lightbar is controlled by an embedded controller (EC),
    + which also manages the keyboard, battery charging, fans,
    + and other system hardware. To prevent unprivileged users
    + from interfering with the other EC functions, the rate at
    + which the lightbar control files can be read or written is
    + limited.
    +
    + Reading this file will return the number of milliseconds
    + that must elapse between accessing any of the lightbar
    + functions through this interface. Going faster will simply
    + block until the necessary interval has lapsed. The interval
    + applies uniformly to all accesses of any kind by any user.
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/led_rgb
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + This allows you to control each LED segment. If the
    + lightbar is already running one of the automatic
    + sequences, you probably won’t see anything change because
    + your color setting will be almost immediately replaced.
    + To get useful results, you should stop the lightbar
    + sequence first.
    +
    + The values written to this file are sets of four integers,
    + indicating LED, RED, GREEN, BLUE. The LED number is 0 to 3
    + to select a single segment, or 4 to set all four segments
    + to the same value at once. The RED, GREEN, and BLUE
    + numbers should be in the range 0 (off) to 255 (maximum).
    + You can update more than one segment at a time by writing
    + more than one set of four integers.
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/program
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + This allows you to upload and run custom lightbar sequences.
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/sequence
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + The Pixel lightbar has a number of built-in sequences
    + that it displays under various conditions, such as at
    + power on, shut down, or while running. Reading from this
    + file displays the current sequence that the lightbar is
    + displaying. Writing to this file allows you to change the
    + sequence.
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/userspace_control
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + This allows you to take the control of the lightbar. This
    + prevents the kernel from going through its normal
    + sequences.
    +
    +What: /sys/class/chromeos/<cros-ec>/lightbar/version
    +Date: August 2015
    +KernelVersion: 4.2
    +Description:
    + Show the information about the lightbar version.
    diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
    index ff788d3e6d5f..614f888c9d6d 100644
    --- a/drivers/mfd/cros_ec_dev.c
    +++ b/drivers/mfd/cros_ec_dev.c
    @@ -36,7 +36,6 @@ static int ec_major;

    static const struct attribute_group *cros_ec_groups[] = {
    &cros_ec_attr_group,
    - &cros_ec_lightbar_attr_group,
    &cros_ec_vbc_attr_group,
    NULL,
    };
    @@ -390,6 +389,10 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
    { .name = "cros-usbpd-charger" }
    };

    +static const struct mfd_cell cros_ec_platform_cells[] = {
    + { .name = "cros-ec-lightbar" },
    +};
    +
    static int ec_device_probe(struct platform_device *pdev)
    {
    int retval = -ENOMEM;
    @@ -464,9 +467,6 @@ static int ec_device_probe(struct platform_device *pdev)
    retval);
    }

    - /* Take control of the lightbar from the EC. */
    - lb_manual_suspend_ctrl(ec, 1);
    -
    /* We can now add the sysfs class, we know which parameter to show */
    retval = cdev_device_add(&ec->cdev, &ec->class_dev);
    if (retval) {
    @@ -474,6 +474,15 @@ static int ec_device_probe(struct platform_device *pdev)
    goto failed;
    }

    + retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
    + cros_ec_platform_cells,
    + ARRAY_SIZE(cros_ec_platform_cells),
    + NULL, 0, NULL);
    + if (retval)
    + dev_warn(ec->dev,
    + "failed to add cros-ec platform devices: %d\n",
    + retval);
    +
    if (cros_ec_debugfs_init(ec))
    dev_warn(dev, "failed to create debugfs directory\n");

    @@ -488,9 +497,6 @@ static int ec_device_remove(struct platform_device *pdev)
    {
    struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);

    - /* Let the EC take over the lightbar again. */
    - lb_manual_suspend_ctrl(ec, 0);
    -
    cros_ec_debugfs_remove(ec);

    mfd_remove_devices(ec->dev);
    @@ -519,8 +525,6 @@ static __maybe_unused int ec_device_suspend(struct device *dev)

    cros_ec_debugfs_suspend(ec);

    - lb_suspend(ec);
    -
    return 0;
    }

    @@ -530,8 +534,6 @@ static __maybe_unused int ec_device_resume(struct device *dev)

    cros_ec_debugfs_resume(ec);

    - lb_resume(ec);
    -
    return 0;
    }

    diff --git a/drivers/mfd/cros_ec_dev.h b/drivers/mfd/cros_ec_dev.h
    index 978d836a0248..ec750433455a 100644
    --- a/drivers/mfd/cros_ec_dev.h
    +++ b/drivers/mfd/cros_ec_dev.h
    @@ -44,10 +44,4 @@ struct cros_ec_readmem {
    #define CROS_EC_DEV_IOCXCMD _IOWR(CROS_EC_DEV_IOC, 0, struct cros_ec_command)
    #define CROS_EC_DEV_IOCRDMEM _IOWR(CROS_EC_DEV_IOC, 1, struct cros_ec_readmem)

    -/* Lightbar utilities */
    -extern bool ec_has_lightbar(struct cros_ec_dev *ec);
    -extern int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable);
    -extern int lb_suspend(struct cros_ec_dev *ec);
    -extern int lb_resume(struct cros_ec_dev *ec);
    -
    #endif /* _CROS_EC_DEV_H_ */
    diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
    index 16b1615958aa..05bcefbe1926 100644
    --- a/drivers/platform/chrome/Kconfig
    +++ b/drivers/platform/chrome/Kconfig
    @@ -111,4 +111,14 @@ config CROS_KBD_LED_BACKLIGHT
    To compile this driver as a module, choose M here: the
    module will be called cros_kbd_led_backlight.

    +config CROS_EC_LIGHTBAR
    + tristate "Chromebook Pixel's lightbar support"
    + depends on MFD_CROS_EC_CHARDEV
    + help
    + This option exposes the Chromebook Pixel's lightbar to
    + userspace.
    +
    + To compile this driver as a module, choose M here: the
    + module will be called cros_ec_lightbar.
    +
    endif # CHROMEOS_PLATFORMS
    diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
    index cd591bf872bb..3c29a4b405d5 100644
    --- a/drivers/platform/chrome/Makefile
    +++ b/drivers/platform/chrome/Makefile
    @@ -3,7 +3,7 @@
    obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o
    obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o
    obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o
    -cros_ec_ctl-objs := cros_ec_sysfs.o cros_ec_lightbar.o \
    +cros_ec_ctl-objs := cros_ec_sysfs.o \
    cros_ec_vbc.o cros_ec_debugfs.o
    obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
    obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
    @@ -13,3 +13,4 @@ cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
    obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
    obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o
    obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o
    +obj-$(CONFIG_CROS_EC_LIGHTBAR) += cros_ec_lightbar.o
    diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
    index 68193bb53383..80eed6317570 100644
    --- a/drivers/platform/chrome/cros_ec_lightbar.c
    +++ b/drivers/platform/chrome/cros_ec_lightbar.c
    @@ -33,6 +33,8 @@
    #include <linux/uaccess.h>
    #include <linux/slab.h>

    +#define DRV_NAME "cros-ec-lightbar"
    +
    /* Rate-limit the lightbar interface to prevent DoS. */
    static unsigned long lb_interval_jiffies = 50 * HZ / 1000;

    @@ -373,7 +375,7 @@ static int lb_send_empty_cmd(struct cros_ec_dev *ec, uint8_t cmd)
    return ret;
    }

    -int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
    +static int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
    {
    struct ec_params_lightbar *param;
    struct cros_ec_command *msg;
    @@ -408,25 +410,6 @@ int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)

    return ret;
    }
    -EXPORT_SYMBOL(lb_manual_suspend_ctrl);
    -
    -int lb_suspend(struct cros_ec_dev *ec)
    -{
    - if (userspace_control || ec != ec_with_lightbar)
    - return 0;
    -
    - return lb_send_empty_cmd(ec, LIGHTBAR_CMD_SUSPEND);
    -}
    -EXPORT_SYMBOL(lb_suspend);
    -
    -int lb_resume(struct cros_ec_dev *ec)
    -{
    - if (userspace_control || ec != ec_with_lightbar)
    - return 0;
    -
    - return lb_send_empty_cmd(ec, LIGHTBAR_CMD_RESUME);
    -}
    -EXPORT_SYMBOL(lb_resume);

    static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
    const char *buf, size_t count)
    @@ -584,7 +567,7 @@ static struct attribute *__lb_cmds_attrs[] = {
    NULL,
    };

    -bool ec_has_lightbar(struct cros_ec_dev *ec)
    +static bool ec_has_lightbar(struct cros_ec_dev *ec)
    {
    return !!get_lightbar_version(ec, NULL, NULL);
    }
    @@ -616,4 +599,72 @@ struct attribute_group cros_ec_lightbar_attr_group = {
    .attrs = __lb_cmds_attrs,
    .is_visible = cros_ec_lightbar_attrs_are_visible,
    };
    -EXPORT_SYMBOL(cros_ec_lightbar_attr_group);
    +
    +static int cros_ec_lightbar_probe(struct platform_device *pd)
    +{
    + struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
    + struct device *dev = &pd->dev;
    + int ret;
    +
    + /* Take control of the lightbar from the EC. */
    + lb_manual_suspend_ctrl(ec_dev, 1);
    +
    + ret = sysfs_create_group(&ec_dev->class_dev.kobj,
    + &cros_ec_lightbar_attr_group);
    + if (ret < 0)
    + dev_err(dev, "failed to create %s attributes. err=%d\n",
    + cros_ec_lightbar_attr_group.name, ret);
    +
    + return ret;
    +}
    +
    +static int cros_ec_lightbar_remove(struct platform_device *pd)
    +{
    + struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
    +
    + sysfs_remove_group(&ec_dev->class_dev.kobj,
    + &cros_ec_lightbar_attr_group);
    +
    + /* Let the EC take over the lightbar again. */
    + lb_manual_suspend_ctrl(ec_dev, 0);
    +
    + return 0;
    +}
    +
    +static int __maybe_unused cros_ec_lightbar_resume(struct device *dev)
    +{
    + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev);
    +
    + if (userspace_control || ec_dev != ec_with_lightbar)
    + return 0;
    +
    + return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_RESUME);
    +}
    +
    +static int __maybe_unused cros_ec_lightbar_suspend(struct device *dev)
    +{
    + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev);
    +
    + if (userspace_control || ec_dev != ec_with_lightbar)
    + return 0;
    +
    + return lb_send_empty_cmd(ec_dev, LIGHTBAR_CMD_SUSPEND);
    +}
    +
    +static SIMPLE_DEV_PM_OPS(cros_ec_lightbar_pm_ops,
    + cros_ec_lightbar_suspend, cros_ec_lightbar_resume);
    +
    +static struct platform_driver cros_ec_lightbar_driver = {
    + .driver = {
    + .name = DRV_NAME,
    + .pm = &cros_ec_lightbar_pm_ops,
    + },
    + .probe = cros_ec_lightbar_probe,
    + .remove = cros_ec_lightbar_remove,
    +};
    +
    +module_platform_driver(cros_ec_lightbar_driver);
    +
    +MODULE_LICENSE("GPL");
    +MODULE_DESCRIPTION("Expose the Chromebook Pixel's lightbar to userspace");
    +MODULE_ALIAS("platform:" DRV_NAME);
    diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
    index 706dd724de52..b6beba3031ba 100644
    --- a/include/linux/mfd/cros_ec.h
    +++ b/include/linux/mfd/cros_ec.h
    @@ -325,7 +325,6 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);

    /* sysfs stuff */
    extern struct attribute_group cros_ec_attr_group;
    -extern struct attribute_group cros_ec_lightbar_attr_group;
    extern struct attribute_group cros_ec_vbc_attr_group;

    /* debugfs stuff */
    --
    2.19.1
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      Last update: 2018-11-27 13:20    [W:3.392 / U:0.036 seconds]
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