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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/video/backlight/rt4831-backlight.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'drivers/video/backlight/rt4831-backlight.c')
| -rw-r--r-- | drivers/video/backlight/rt4831-backlight.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/video/backlight/rt4831-backlight.c b/drivers/video/backlight/rt4831-backlight.c new file mode 100644 index 000000000..7ead75929 --- /dev/null +++ b/drivers/video/backlight/rt4831-backlight.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <dt-bindings/leds/rt4831-backlight.h> +#include <linux/backlight.h> +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/regmap.h> + +#define RT4831_REG_BLCFG 0x02 +#define RT4831_REG_BLDIML 0x04 +#define RT4831_REG_ENABLE 0x08 +#define RT4831_REG_BLOPT2 0x11 + +#define RT4831_BLMAX_BRIGHTNESS 2048 + +#define RT4831_BLOVP_MASK GENMASK(7, 5) +#define RT4831_BLOVP_SHIFT 5 +#define RT4831_BLPWMEN_MASK BIT(0) +#define RT4831_BLEN_MASK BIT(4) +#define RT4831_BLCH_MASK GENMASK(3, 0) +#define RT4831_BLDIML_MASK GENMASK(2, 0) +#define RT4831_BLDIMH_MASK GENMASK(10, 3) +#define RT4831_BLDIMH_SHIFT 3 +#define RT4831_BLOCP_MASK GENMASK(1, 0) + +#define RT4831_BLOCP_MINUA 900000 +#define RT4831_BLOCP_MAXUA 1800000 +#define RT4831_BLOCP_STEPUA 300000 + +struct rt4831_priv { + struct device *dev; + struct regmap *regmap; + struct backlight_device *bl; +}; + +static int rt4831_bl_update_status(struct backlight_device *bl_dev) +{ + struct rt4831_priv *priv = bl_get_data(bl_dev); + int brightness = backlight_get_brightness(bl_dev); + unsigned int enable = brightness ? RT4831_BLEN_MASK : 0; + u8 v[2]; + int ret; + + if (brightness) { + v[0] = (brightness - 1) & RT4831_BLDIML_MASK; + v[1] = ((brightness - 1) & RT4831_BLDIMH_MASK) >> RT4831_BLDIMH_SHIFT; + + ret = regmap_raw_write(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v)); + if (ret) + return ret; + } + + return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLEN_MASK, enable); + +} + +static int rt4831_bl_get_brightness(struct backlight_device *bl_dev) +{ + struct rt4831_priv *priv = bl_get_data(bl_dev); + unsigned int val; + u8 v[2]; + int ret; + + ret = regmap_read(priv->regmap, RT4831_REG_ENABLE, &val); + if (ret) + return ret; + + if (!(val & RT4831_BLEN_MASK)) + return 0; + + ret = regmap_raw_read(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v)); + if (ret) + return ret; + + ret = (v[1] << RT4831_BLDIMH_SHIFT) + (v[0] & RT4831_BLDIML_MASK) + 1; + + return ret; +} + +static const struct backlight_ops rt4831_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = rt4831_bl_update_status, + .get_brightness = rt4831_bl_get_brightness, +}; + +static int rt4831_parse_backlight_properties(struct rt4831_priv *priv, + struct backlight_properties *bl_props) +{ + struct device *dev = priv->dev; + u8 propval; + u32 brightness, ocp_uA; + unsigned int val = 0; + int ret; + + /* common properties */ + ret = device_property_read_u32(dev, "max-brightness", &brightness); + if (ret) + brightness = RT4831_BLMAX_BRIGHTNESS; + + bl_props->max_brightness = min_t(u32, brightness, RT4831_BLMAX_BRIGHTNESS); + + ret = device_property_read_u32(dev, "default-brightness", &brightness); + if (ret) + brightness = bl_props->max_brightness; + + bl_props->brightness = min_t(u32, brightness, bl_props->max_brightness); + + /* vendor properties */ + if (device_property_read_bool(dev, "richtek,pwm-enable")) + val = RT4831_BLPWMEN_MASK; + + ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLPWMEN_MASK, val); + if (ret) + return ret; + + ret = device_property_read_u8(dev, "richtek,bled-ovp-sel", &propval); + if (ret) + propval = RT4831_BLOVPLVL_21V; + + propval = min_t(u8, propval, RT4831_BLOVPLVL_29V); + ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLOVP_MASK, + propval << RT4831_BLOVP_SHIFT); + if (ret) + return ret; + + /* + * This OCP level is used to protect and limit the inductor current. + * If inductor peak current reach the level, low-side MOSFET will be + * turned off. Meanwhile, the output channel current may be limited. + * To match the configured channel current, the inductor chosen must + * be higher than the OCP level. + * + * Not like the OVP level, the default 21V can be used in the most + * application. But if the chosen OCP level is smaller than needed, + * it will also affect the backlight channel output current to be + * smaller than the register setting. + */ + ret = device_property_read_u32(dev, "richtek,bled-ocp-microamp", + &ocp_uA); + if (!ret) { + ocp_uA = clamp_val(ocp_uA, RT4831_BLOCP_MINUA, + RT4831_BLOCP_MAXUA); + val = DIV_ROUND_UP(ocp_uA - RT4831_BLOCP_MINUA, + RT4831_BLOCP_STEPUA); + ret = regmap_update_bits(priv->regmap, RT4831_REG_BLOPT2, + RT4831_BLOCP_MASK, val); + if (ret) + return ret; + } + + ret = device_property_read_u8(dev, "richtek,channel-use", &propval); + if (ret) { + dev_err(dev, "richtek,channel-use DT property missing\n"); + return ret; + } + + if (!(propval & RT4831_BLCH_MASK)) { + dev_err(dev, "No channel specified\n"); + return -EINVAL; + } + + return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLCH_MASK, propval); +} + +static int rt4831_bl_probe(struct platform_device *pdev) +{ + struct rt4831_priv *priv; + struct backlight_properties bl_props = { .type = BACKLIGHT_RAW, + .scale = BACKLIGHT_SCALE_LINEAR }; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = &pdev->dev; + + priv->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!priv->regmap) { + dev_err(&pdev->dev, "Failed to init regmap\n"); + return -ENODEV; + } + + ret = rt4831_parse_backlight_properties(priv, &bl_props); + if (ret) { + dev_err(&pdev->dev, "Failed to parse backlight properties\n"); + return ret; + } + + priv->bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev, priv, + &rt4831_bl_ops, &bl_props); + if (IS_ERR(priv->bl)) { + dev_err(&pdev->dev, "Failed to register backlight\n"); + return PTR_ERR(priv->bl); + } + + backlight_update_status(priv->bl); + platform_set_drvdata(pdev, priv); + + return 0; +} + +static void rt4831_bl_remove(struct platform_device *pdev) +{ + struct rt4831_priv *priv = platform_get_drvdata(pdev); + struct backlight_device *bl_dev = priv->bl; + + bl_dev->props.brightness = 0; + backlight_update_status(priv->bl); +} + +static const struct of_device_id __maybe_unused rt4831_bl_of_match[] = { + { .compatible = "richtek,rt4831-backlight", }, + {} +}; +MODULE_DEVICE_TABLE(of, rt4831_bl_of_match); + +static struct platform_driver rt4831_bl_driver = { + .driver = { + .name = "rt4831-backlight", + .of_match_table = rt4831_bl_of_match, + }, + .probe = rt4831_bl_probe, + .remove = rt4831_bl_remove, +}; +module_platform_driver(rt4831_bl_driver); + +MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>"); +MODULE_DESCRIPTION("Richtek RT4831 Backlight Driver"); +MODULE_LICENSE("GPL v2"); |
