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 platform devices 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: Kenneth Chan <kenneth.t.chan@xxxxxxxxx> --- drivers/platform/x86/panasonic-laptop.c | 109 ++++++++++++++++++++++++ 1 file changed, 109 insertions(+) diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c index 6355d60dc3eb..6388c3c705a6 100644 --- a/drivers/platform/x86/panasonic-laptop.c +++ b/drivers/platform/x86/panasonic-laptop.c @@ -13,6 +13,7 @@ * * ChangeLog: * Aug.18, 2020 Kenneth Chan <kenneth.t.chan@xxxxxxxxx> + * -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@xxxxxxxxxx>"); MODULE_AUTHOR("David Bronaugh <dbronaugh@xxxxxxxxxxxxxx>"); MODULE_AUTHOR("Harald Welte <laforge@xxxxxxxxxxxx>"); @@ -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); -- 2.17.5
