Commit 25dd390c authored by Kenneth Chan's avatar Kenneth Chan Committed by Hans de Goede
Browse files

platform/x86: panasonic-laptop: Add sysfs attributes for firmware brightness registers 

Panasonic laptops (at least from CF-W4 onwards) have dedicated firmware
registers for saving ac/dc and current brightness. They are a bit confusing
so here's some explanations:

AC_MIN_BRIGHT, AC_MAX_BRIGHT, DC_MIN_BRIGHT, DC_MAX_BRIGHT:
Read-only. Values: 0x01 and 0x15 respectively.

AC_CUR_BRIGHT, DC_CUR_BRIGHT:
Read-Write. 0x00-0xFF. Store user-defined AC/DC brightness. However,
they do not represent current brightness so they should be named AC_BRIGHT
and DC_BRIGHT instead.

CUR_BRIGHT (present since CF-W4):
Read-Write. 0x00-0xFF. It sets the current brightness. It won't update
itself if brightness is changed via other means, e.g. acpi_video0.

Another CUR_BRIGHT (added since CF-W5):
Read-Write. 0x01-0x15. Its value always synchronizes with current
brightness. Not implemented in this version.

Currently the backlight API interacts with AC_CUR_BRIGHT (probably because
it's the only bl register available in earlier models?). This patch adds
sysfs attributes for AC_CUR_BRIGHT, DC_CUR_BRIGHT and CUR_BRIGHT.

It also fixes the error of https://lkml.org/lkml/2020/8/19/1264

.

PS: I think the backlight API should interact with CUR_BRIGHT instead of
AC_CUR_BRIGHT. But it involves complications like mapping between 0x01-0x15
or 0x00-0x14 (the backlight API) and 0x00-0xFF (CUR_BRIGHT). I'll leave the
discussion for a later version.

Signed-off-by: default avatarKenneth Chan <kenneth.t.chan@gmail.com>
Link: https://lore.kernel.org/r/20200821181433.17653-10-kenneth.t.chan@gmail.com


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 468f96bf

drivers/platform/x86/panasonic-laptop.c

+109 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
 *

 * ChangeLog:

 *	Aug.18, 2020	Kenneth Chan <kenneth.t.chan@gmail.com>

 *		-v0.98	add platform devices for firmware brightness registers

 *			add support for battery charging threshold (eco mode)

 *			resolve hotkey double trigger

 *			add write support to mute
@@ -132,6 +133,7 @@ 
#include <linux/input/sparse-keymap.h>

#include <linux/platform_device.h>





MODULE_AUTHOR("Hiroshi Miura <miura@da-cha.org>");

MODULE_AUTHOR("David Bronaugh <dbronaugh@linuxboxen.org>");

MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
@@ -173,6 +175,7 @@ enum SINF_BITS { SINF_NUM_BATTERIES = 0, 
		 SINF_MUTE,

		 SINF_RESERVED,

		 SINF_ECO_MODE = 0x0A,

		 SINF_CUR_BRIGHT = 0x0D,

		 SINF_STICKY_KEY = 0x80,

	};

/* R1 handles SINF_AC_CUR_BRIGHT as SINF_CUR_BRIGHT, doesn't know AC state */
@@ -228,6 +231,9 @@ struct pcc_acpi { 
	int			sticky_key;

	int			eco_mode;

	int			mute;

	int			ac_brightness;

	int			dc_brightness;

	int			current_brightness;

	u32			*sinf;

	struct acpi_device	*device;

	struct input_dev	*input_dev;
@@ -610,6 +616,97 @@ static ssize_t eco_mode_store(struct device *dev, struct device_attribute *attr, 
	return count;

}



static ssize_t ac_brightness_show(struct device *dev, struct device_attribute *attr,

				  char *buf)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);



	if (!acpi_pcc_retrieve_biosdata(pcc))

		return -EIO;



	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_AC_CUR_BRIGHT]);

}



static ssize_t ac_brightness_store(struct device *dev, struct device_attribute *attr,

				   const char *buf, size_t count)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	int err, val;



	err = kstrtoint(buf, 0, &val);

	if (err)

		return err;

	if (val >= 0 && val <= 255) {

		acpi_pcc_write_sset(pcc, SINF_AC_CUR_BRIGHT, val);

		pcc->ac_brightness = val;

	}



	return count;

}



static ssize_t dc_brightness_show(struct device *dev, struct device_attribute *attr,

				  char *buf)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);



	if (!acpi_pcc_retrieve_biosdata(pcc))

		return -EIO;



	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_DC_CUR_BRIGHT]);

}



static ssize_t dc_brightness_store(struct device *dev, struct device_attribute *attr,

				   const char *buf, size_t count)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	int err, val;



	err = kstrtoint(buf, 0, &val);

	if (err)

		return err;

	if (val >= 0 && val <= 255) {

		acpi_pcc_write_sset(pcc, SINF_DC_CUR_BRIGHT, val);

		pcc->dc_brightness = val;

	}



	return count;

}



static ssize_t current_brightness_show(struct device *dev, struct device_attribute *attr,

				       char *buf)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);



	if (!acpi_pcc_retrieve_biosdata(pcc))

		return -EIO;



	return snprintf(buf, PAGE_SIZE, "%u\n", pcc->sinf[SINF_CUR_BRIGHT]);

}



static ssize_t current_brightness_store(struct device *dev, struct device_attribute *attr,

					const char *buf, size_t count)

{

	struct acpi_device *acpi = to_acpi_device(dev);

	struct pcc_acpi *pcc = acpi_driver_data(acpi);

	int err, val;



	err = kstrtoint(buf, 0, &val);

	if (err)

		return err;



	if (val >= 0 && val <= 255) {

		err = acpi_pcc_write_sset(pcc, SINF_CUR_BRIGHT, val);

		pcc->current_brightness = val;

	}



	return count;

}



static ssize_t cdpower_show(struct device *dev, struct device_attribute *attr,

			    char *buf)

{
@@ -633,6 +730,9 @@ static DEVICE_ATTR_RO(lcdtype); 
static DEVICE_ATTR_RW(mute);

static DEVICE_ATTR_RW(sticky_key);

static DEVICE_ATTR_RW(eco_mode);

static DEVICE_ATTR_RW(ac_brightness);

static DEVICE_ATTR_RW(dc_brightness);

static DEVICE_ATTR_RW(current_brightness);

static DEVICE_ATTR_RW(cdpower);



static struct attribute *pcc_sysfs_entries[] = {
@@ -641,6 +741,9 @@ static struct attribute *pcc_sysfs_entries[] = { 
	&dev_attr_mute.attr,

	&dev_attr_sticky_key.attr,

	&dev_attr_eco_mode.attr,

	&dev_attr_ac_brightness.attr,

	&dev_attr_dc_brightness.attr,

	&dev_attr_current_brightness.attr,

	&dev_attr_cdpower.attr,

	NULL,

};
@@ -794,6 +897,9 @@ static int acpi_pcc_hotkey_resume(struct device *dev) 
	acpi_pcc_write_sset(pcc, SINF_MUTE, pcc->mute);

	acpi_pcc_write_sset(pcc, SINF_ECO_MODE, pcc->eco_mode);

	acpi_pcc_write_sset(pcc, SINF_STICKY_KEY, pcc->sticky_key);

	acpi_pcc_write_sset(pcc, SINF_AC_CUR_BRIGHT, pcc->ac_brightness);

	acpi_pcc_write_sset(pcc, SINF_DC_CUR_BRIGHT, pcc->dc_brightness);

	acpi_pcc_write_sset(pcc, SINF_CUR_BRIGHT, pcc->current_brightness);



	return 0;

}
@@ -865,6 +971,9 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device) 


	pcc->eco_mode = pcc->sinf[SINF_ECO_MODE];

	pcc->mute = pcc->sinf[SINF_MUTE];

	pcc->ac_brightness = pcc->sinf[SINF_AC_CUR_BRIGHT];

	pcc->dc_brightness = pcc->sinf[SINF_DC_CUR_BRIGHT];

	result = pcc->current_brightness = pcc->sinf[SINF_CUR_BRIGHT];



	/* add sysfs attributes */

	result = sysfs_create_group(&device->dev.kobj, &pcc_attr_group);