Hi Martin.
To an end user, writing "0" to enable the device & "1" to disable it
sounds counter-intuitive, especially when the sysfs entry is called
"cdpower". Is there a reason to not flip that?
Regards,
Karthik
On Tue, Jan 13, 2009 at 11:32 AM, Martin Lucina <mato@xxxxxxxxxx> wrote:
> Hello,
>
> attached is a patch to the panasonic-laptop driver to enable power
> management (i.e. on/off) of the built-in optical drive. It creates a
> sysfs interface /sys/devices/platform/panasonic/cdpower which can be
> either queried or written to. Writing "0" enables the device, "1"
> disables it.
>
> This code is based on reading the existing code[1][2],
> examining the DSDT on my CF-W4 system and experimentation.
>
> The presence of the CF-Y series in the DMI table is based on the
> assumption that this method works on recent CF-Yx models.
>
> I have a few questions I'd like to clear up before actually submitting
> this for inclusion:
>
> 1) Is a platform device the right way to do this?
>
> 2) Rather than checking the DMI system vendor and product name would it
> be a better approach to simply check for the presence of the \_SB.FBAY()
> and \_SB.STAT() ACPI methods and enable the platform device on any
> (Panasonic) system where these are present? This would seem like a
> more future-proof approach.
>
> 3) Please advise on the correct way to propagate an error result from
> the functions that call the ACPI methods {get,set}optd_power_state() to
> userspace in the sysfs interface. I couldn't find a straightforward
> example anywhere.
>
> Thanks!
>
> -mato
>
> [1] Referenced here http://www.da-cha.jp/letsnote as "A patch to handle
> CD on/off button(need to merge)" (now a dead link)
> [2] http://www.netlab.is.tsukuba.ac.jp/~yokota/izumi/panasonic_acpi/,
> see the 20070907 version ("includes small hack for CD-ROM drive")
>
> ---
>
> --- linux-2.6.28/drivers/misc/panasonic-laptop.c.orig 2009-01-13 17:01:53.327106958 +0100
> +++ linux-2.6.28/drivers/misc/panasonic-laptop.c 2009-01-13 17:04:04.911106197 +0100
> @@ -24,6 +24,8 @@
> *---------------------------------------------------------------------------
> *
> * ChangeLog:
> + * Jan.13, 2009 Martin Lucina <mato@xxxxxxxxxx>
> + * -v0.96 add support for optical drive power in Y and W series
> * Sep.23, 2008 Harald Welte <laforge@xxxxxxxxxxxx>
> * -v0.95 rename driver from drivers/acpi/pcc_acpi.c to
> * drivers/misc/panasonic-laptop.c
> @@ -127,6 +129,8 @@
> #include <acpi/acpi_bus.h>
> #include <acpi/acpi_drivers.h>
> #include <linux/input.h>
> +#include <linux/platform_device.h>
> +#include <linux/dmi.h>
>
>
> #ifndef ACPI_HOTKEY_COMPONENT
> @@ -219,6 +223,7 @@ struct pcc_acpi {
> struct acpi_device *device;
> struct input_dev *input_dev;
> struct backlight_device *backlight;
> + struct platform_device *platform;
> int keymap[KEYMAP_SIZE];
> };
>
> @@ -226,6 +231,27 @@ struct pcc_keyinput {
> struct acpi_hotkey *hotkey;
> };
>
> +/* known models with optical drive */
> +static struct dmi_system_id pcc_platform_dmi_table[] = {
> + {
> + .ident = "Panasonic Toughbook W Series",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR,
> + "Matsushita Electric Industrial Co.,Ltd."),
> + DMI_MATCH(DMI_PRODUCT_NAME, "CF-W"),
> + },
> + },
> + {
> + .ident = "Panasonic Toughbook Y Series",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR,
> + "Matsushita Electric Industrial Co.,Ltd."),
> + DMI_MATCH(DMI_PRODUCT_NAME, "CF-Y"),
> + },
> + },
> + { }
> +};
> +
> /* method access functions */
> static int acpi_pcc_write_sset(struct pcc_acpi *pcc, int func, int val)
> {
> @@ -360,6 +386,63 @@ static struct backlight_ops pcc_backligh
> .update_status = bl_set_status,
> };
>
> +/* get optical driver power state */
> +
> +static int get_optd_power_state(void)
> +{
> + acpi_status status;
> + unsigned long long state;
> + int result;
> +
> + status = acpi_evaluate_integer(NULL, "\\_SB.STAT", NULL, &state);
> + if (ACPI_FAILURE(status)) {
> + result = -EIO;
> + goto out;
> + }
> + switch (state) {
> + case 0: /* power off */
> + result = 1;
> + break;
> + case 0x0f: /* power on */
> + result = 0;
> + break;
> + default:
> + result = -EIO;
> + break;
> + }
> +out:
> + return result;
> +}
> +
> +/* set optical drive power state */
> +
> +static int set_optd_power_state(int new_state)
> +{
> + int state, result;
> + acpi_status status;
> +
> + state = get_optd_power_state();
> + if (new_state == state)
> + return 0;
> +
> + result = 0;
> + switch (new_state) {
> + case 0: /* power on */
> + status = acpi_evaluate_object (NULL, "\\_SB.FBAY", NULL, NULL);
> + if (ACPI_FAILURE(status))
> + result = -EIO;
> + break;
> + case 1: /* power off */
> + status = acpi_evaluate_object (NULL, "\\_SB.CDDI", NULL, NULL);
> + if (ACPI_FAILURE(status))
> + result = -EIO;
> + break;
> + default:
> + result = -EINVAL;
> + break;
> + }
> + return result;
> +}
>
> /* sysfs user interface functions */
>
> @@ -427,10 +510,29 @@ static ssize_t set_sticky(struct device
> return count;
> }
>
> +static ssize_t show_cdpower(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + return snprintf(buf, PAGE_SIZE, "%d\n", get_optd_power_state());
> +}
> +
> +static ssize_t set_cdpower(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + int value;
> +
> + if (count) {
> + value = simple_strtoul(buf, NULL, 10);
> + set_optd_power_state (value);
> + }
> + return count;
> +}
> +
> static DEVICE_ATTR(numbatt, S_IRUGO, show_numbatt, NULL);
> static DEVICE_ATTR(lcdtype, S_IRUGO, show_lcdtype, NULL);
> static DEVICE_ATTR(mute, S_IRUGO, show_mute, NULL);
> static DEVICE_ATTR(sticky_key, S_IRUGO | S_IWUSR, show_sticky, set_sticky);
> +static DEVICE_ATTR(cdpower, S_IRUGO | S_IWUSR, show_cdpower, set_cdpower);
>
> static struct attribute *pcc_sysfs_entries[] = {
> &dev_attr_numbatt.attr,
> @@ -691,8 +793,26 @@ static int acpi_pcc_hotkey_add(struct ac
> if (result)
> goto out_backlight;
>
> + /* platform device initialization */
> + if (!dmi_check_system(pcc_platform_dmi_table)) {
> + pcc->platform = NULL;
> + goto out_no_optd;
> + }
> + pcc->platform = platform_device_register_simple("panasonic", -1,
> + NULL, 0);
> + if (IS_ERR(pcc->platform)) {
> + result = PTR_ERR(pcc->platform);
> + goto out_backlight;
> + }
> + result = device_create_file(&pcc->platform->dev, &dev_attr_cdpower);
> + if (result)
> + goto out_platform;
> +
> +out_no_optd:
> return 0;
>
> +out_platform:
> + platform_device_unregister(pcc->platform);
> out_backlight:
> backlight_device_unregister(pcc->backlight);
> out_notify:
> @@ -738,6 +858,11 @@ static int acpi_pcc_hotkey_remove(struct
> if (!device || !pcc)
> return -EINVAL;
>
> + if (pcc->platform) {
> + device_remove_file(&pcc->platform->dev, &dev_attr_cdpower);
> + platform_device_unregister(pcc->platform);
> + }
> +
> sysfs_remove_group(&device->dev.kobj, &pcc_attr_group);
>
> backlight_device_unregister(pcc->backlight);
> --
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