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auxdisplay: vk2c21: add sysfs brightness control #501

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01a2f67
input: remotectl: rockchip-pwm: prefer dedicated channel-3 IRQ
rpardini Jun 12, 2026
48e2ace
auxdisplay: vk2c21: add sysfs brightness control
rpardini Jun 14, 2026
7585a63
video: rockchip: mpp: report zero load for idle devices
rpardini Jul 14, 2026
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62 changes: 61 additions & 1 deletion drivers/auxdisplay/lcd-vk2c21.c
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,23 @@
#define VK2C21_SYS_OFF_LCD_OFF 0x00 /* System + LCD off */
#define VK2C21_FRAME_80HZ 0x00 /* 80 Hz frame rate */
#define VK2C21_BLINK_OFF 0x00 /* Blinking off */
#define VK2C21_IVA_DEFAULT 0x0F /* VLCD selected, IVA off, R1 */
#define VK2C21_IVA_DEFAULT 0x0F /* VLCD selected, IVA off, R1 (external VR) */

/*
* IVA on, SEG mode: 16 internal bias-voltage levels.
* 0x30 = level 0 = 1.000 x VDD (highest contrast / "brightest")
* 0x3F = level 15 = 0.529 x VDD (lowest contrast / "dimmest")
* SEG mode (vs. VLCD-output mode at 0x10..0x1F) is used because the R58X-Pro
* has an external resistor on the VLCD pin: in VLCD-output mode the external
* resistor dominates the chip's internal driver and the brightness register
* has no visible effect. SEG mode tells the chip to ignore the VLCD pin and
* generate the bias voltage purely internally.
* Userspace brightness is inverted (0 = dimmest, 15 = brightest) so that
* higher numbers look brighter, matching the usual convention.
*/
#define VK2C21_IVA_ON_BASE 0x30
#define VK2C21_BRIGHTNESS_MAX 15
#define VK2C21_BRIGHTNESS_DEFAULT (-1) /* IVA off, external VR in use */

/* Display RAM has 10 addressable bytes (SEG/COM matrix) */
#define VK2C21_RAM_SIZE 10
Expand Down Expand Up @@ -185,6 +201,7 @@ struct vk2c21_data {
unsigned int half_period_ns;
u8 dispram[VK2C21_RAM_SIZE];
char display_text[VK2C21_MAX_DIGITS + 1];
int brightness; /* -1 = IVA off / "default", 0..15 = IVA level */
};

/* ------------------------------------------------------------------ */
Expand Down Expand Up @@ -414,9 +431,51 @@ static ssize_t clear_store(struct device *dev,
}
static DEVICE_ATTR_WO(clear);

static ssize_t brightness_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct vk2c21_data *d = dev_get_drvdata(dev);

if (d->brightness == VK2C21_BRIGHTNESS_DEFAULT)
return sysfs_emit(buf, "default\n");
return sysfs_emit(buf, "%d\n", d->brightness);
}

static ssize_t brightness_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct vk2c21_data *d = dev_get_drvdata(dev);
int ret, level;
u8 iva;

if (sysfs_streq(buf, "default")) {
level = VK2C21_BRIGHTNESS_DEFAULT;
iva = VK2C21_IVA_DEFAULT;
} else {
ret = kstrtoint(buf, 0, &level);
if (ret)
return ret;
if (level < 0 || level > VK2C21_BRIGHTNESS_MAX)
return -EINVAL;
/* Invert: userspace 15 = brightest = IVA level 0 = 0x30 */
iva = VK2C21_IVA_ON_BASE + (VK2C21_BRIGHTNESS_MAX - level);
}

mutex_lock(&d->lock);
ret = vk2c21_send_cmd(d, VK2C21_IVASET, iva);
if (!ret)
d->brightness = level;
mutex_unlock(&d->lock);

return ret ? ret : count;
}
static DEVICE_ATTR_RW(brightness);

static struct attribute *vk2c21_sysfs_attrs[] = {
&dev_attr_display.attr,
&dev_attr_clear.attr,
&dev_attr_brightness.attr,
NULL,
};

Expand Down Expand Up @@ -445,6 +504,7 @@ static int vk2c21_probe(struct platform_device *pdev)
return -ENOMEM;

d->dev = dev;
d->brightness = VK2C21_BRIGHTNESS_DEFAULT;
mutex_init(&d->lock);
platform_set_drvdata(pdev, d);

Expand Down
12 changes: 11 additions & 1 deletion drivers/input/remotectl/rockchip_pwm_remotectl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -932,7 +932,17 @@ static int rk_pwm_probe(struct platform_device *pdev)
input->id.product = 0x0006;
input->id.version = 0x0100;
ddata->input = input;
irq = platform_get_irq(pdev, 0);
/*
* On PWM v4 (RK3588), channel 3 has a dedicated capture IRQ at
* index 1, separate from the group IRQ at index 0 that is shared
* with the other channels in the same PWM controller. Prefer the
* dedicated one so we don't collide with the pwm-rockchip driver
* bound to another channel (which claims the group IRQ without
* IRQF_SHARED on v4). Fall back to index 0 for older PWM v1-v3.
*/
irq = platform_get_irq(pdev, 1);
if (irq < 0)
irq = platform_get_irq(pdev, 0);
Comment on lines +943 to +945

@coderabbitai coderabbitai Bot Jul 14, 2026

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🩺 Stability & Availability | 🟠 Major | ⚡ Quick win

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
set -eu

platform_c="$(rg --files | rg '(^|/)drivers/base/platform\.c$' | head -n1)"
test -n "$platform_c"

rg -n -A35 'int platform_get_irq_optional' "$platform_c" |
  rg -- '-EPROBE_DEFER|-ENXIO|platform_get_irq'

Repository: armbian/linux-rockchip

Length of output: 2137

Don’t fall back on all IRQ errors here. platform_get_irq(pdev, 1) can return -EPROBE_DEFER; this "< 0" check would drop to IRQ 0 instead of deferring probe. Use platform_get_irq_optional(pdev, 1) and fall back only on -ENXIO.

🤖 Prompt for AI Agents 
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@drivers/input/remotectl/rockchip_pwm_remotectl.c` around lines 943 - 945,
Update the IRQ lookup around platform_get_irq in the probe path to use
platform_get_irq_optional(pdev, 1), preserving -EPROBE_DEFER and other errors.
Fall back to platform_get_irq_optional(pdev, 0) only when the first lookup
returns -ENXIO, rather than for every negative result.

Source: MCP tools

if (irq < 0) {
dev_err(&pdev->dev, "cannot find IRQ\n");
goto error_pclk;
Expand Down
24 changes: 22 additions & 2 deletions drivers/video/rockchip/mpp/mpp_service.c
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Original file line number Diff line number Diff line change
Expand Up @@ -329,13 +329,33 @@ static int mpp_show_device_load(struct seq_file *file, void *v)

for (j = 0; j < MPP_MAX_CORE_NUM; j++) {
struct mpp_dev *mpp = queue->cores[j];
struct mpp_load_info *load_info;
u32 load, load_frac, util, util_frac;

if (!mpp)
continue;

load_info = &mpp->load_info;
load = load_info->load;
load_frac = load_info->load_frac;
util = load_info->utilization;
util_frac = load_info->utilization_frac;

/*
* load_info is only refreshed by mpp_dev_load() on task
* completion, so an idle device keeps reporting the last
* busy interval forever. If no task has updated the stats
* for more than one load_interval, the device has gone
* idle: report zero instead of the stale snapshot.
*/
if (!mpp->load_en ||
ktime_us_delta(ktime_get(), load_info->load_time) >
(s64)srv->load_interval * 1000 * 2)
load = load_frac = util = util_frac = 0;

seq_printf(file, "%-25s load: %3d.%02d%% utilization: %3d.%02d%%\n",
dev_name(mpp->dev),
mpp->load_info.load, mpp->load_info.load_frac,
mpp->load_info.utilization, mpp->load_info.utilization_frac);
load, load_frac, util, util_frac);
}
}

Expand Down
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