diff mbox series

[RESEND,v6,1/4] mfd: rt4831: Adds support for Richtek RT4831

Message ID 1619421491-31494-1-git-send-email-u0084500@gmail.com
State Superseded
Headers show
Series [RESEND,v6,1/4] mfd: rt4831: Adds support for Richtek RT4831 | expand

Commit Message

cy_huang April 26, 2021, 7:18 a.m. UTC
From: ChiYuan Huang <cy_huang@richtek.com>

This adds support Richtek RT4831 core. It includes four channel WLED driver
and Display Bias Voltage outputs.

Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
---
Resend this v6 patch series to loop devicetree reviewers.

The RT4831 regulator patches are already on main stream, and can be referred to
9351ab8b0cb6 regulator: rt4831: Adds support for Richtek RT4831 DSV regulator
934b05e81862 regulator: rt4831: Adds DT binding document for Richtek RT4831 DSV regulator

since v6
- Respin the date from 2020 to 2021.
- Rmove the shutdown routine.
- Change the macro OF_MFD_CELL to MFD_CELL_OF.


since v5
- Rename file name from rt4831-core.c to rt4831.c
- Change RICHTEK_VID to RICHTEK_VENDOR_ID.
- Change gpio_desc nameing from 'enable' to 'enable_gpio' in probe.
- Change variable 'val' to the meaningful name 'chip_id'.
- Refine the error log when vendor id is not matched.
- Remove of_match_ptr.

since v2
- Refine Kconfig descriptions.
- Add copyright.
- Refine error logs in probe.
- Refine comment lines in remove and shutdown.
---
 drivers/mfd/Kconfig  |  10 +++++
 drivers/mfd/Makefile |   1 +
 drivers/mfd/rt4831.c | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 126 insertions(+)
 create mode 100644 drivers/mfd/rt4831.c

Comments

cy_huang April 26, 2021, 10:50 a.m. UTC | #1
Hi,

Daniel Thompson <daniel.thompson@linaro.org> 於 2021年4月26日 週一 下午6:19寫道:
>
> On Mon, Apr 26, 2021 at 03:18:11PM +0800, cy_huang wrote:
> > From: ChiYuan Huang <cy_huang@richtek.com>
> >
> > Adds support for Richtek RT4831 backlight.
> >
> > Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> > ---
> > Resend this v6 patch series to loop devicetree reviewers.
> >
> > For next, if the typo in Kconfig 'common' to 'commonly' can be added the below line
> > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> > ---
>
> This isn't the best way to handle feedback from multiple maintainers.
>
> It is great to see you are keeping track of feedback. However it doesn't
> make sense to RESEND an old patchset and acknowledge that you haven't
> fixed a typo yet.
>
> It would be better to fix the typo and to resend a v7.
>
You can refer to the below reply
https://lkml.org/lkml/2021/4/23/229

>
> Daniel.
>
>
> >  drivers/video/backlight/Kconfig            |   8 ++
> >  drivers/video/backlight/Makefile           |   1 +
> >  drivers/video/backlight/rt4831-backlight.c | 203 +++++++++++++++++++++++++++++
> >  3 files changed, 212 insertions(+)
> >  create mode 100644 drivers/video/backlight/rt4831-backlight.c
> >
> > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> > index d83c87b..de96441 100644
> > --- a/drivers/video/backlight/Kconfig
> > +++ b/drivers/video/backlight/Kconfig
> > @@ -289,6 +289,14 @@ config BACKLIGHT_QCOM_WLED
> >         If you have the Qualcomm PMIC, say Y to enable a driver for the
> >         WLED block. Currently it supports PM8941 and PMI8998.
> >
> > +config BACKLIGHT_RT4831
> > +     tristate "Richtek RT4831 Backlight Driver"
> > +     depends on MFD_RT4831
> > +     help
> > +       This enables support for Richtek RT4831 Backlight driver.
> > +       It's common used to drive the display WLED. There're four channels
> > +       inisde, and each channel can provide up to 30mA current.
> > +
> >  config BACKLIGHT_SAHARA
> >       tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
> >       depends on X86
> > diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile
> > index 685f3f1..cae2c83 100644
> > --- a/drivers/video/backlight/Makefile
> > +++ b/drivers/video/backlight/Makefile
> > @@ -49,6 +49,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA)             += pandora_bl.o
> >  obj-$(CONFIG_BACKLIGHT_PCF50633)     += pcf50633-backlight.o
> >  obj-$(CONFIG_BACKLIGHT_PWM)          += pwm_bl.o
> >  obj-$(CONFIG_BACKLIGHT_QCOM_WLED)    += qcom-wled.o
> > +obj-$(CONFIG_BACKLIGHT_RT4831)               += rt4831-backlight.o
> >  obj-$(CONFIG_BACKLIGHT_SAHARA)               += kb3886_bl.o
> >  obj-$(CONFIG_BACKLIGHT_SKY81452)     += sky81452-backlight.o
> >  obj-$(CONFIG_BACKLIGHT_TOSA)         += tosa_bl.o
> > diff --git a/drivers/video/backlight/rt4831-backlight.c b/drivers/video/backlight/rt4831-backlight.c
> > new file mode 100644
> > index 00000000..42155c7
> > --- /dev/null
> > +++ b/drivers/video/backlight/rt4831-backlight.c
> > @@ -0,0 +1,203 @@
> > +// 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_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
> > +
> > +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;
> > +     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;
> > +
> > +     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 int 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);
> > +
> > +     return 0;
> > +}
> > +
> > +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_LICENSE("GPL v2");
> > --
> > 2.7.4
> >
diff mbox series

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b74efa4..3f43834 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1065,6 +1065,16 @@  config MFD_RDC321X
 	  southbridge which provides access to GPIOs and Watchdog using the
 	  southbridge PCI device configuration space.
 
+config MFD_RT4831
+	tristate "Richtek RT4831 four channel WLED and Display Bias Voltage"
+	depends on I2C
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  This enables support for the Richtek RT4831 that includes 4 channel
+	  WLED driving and Display Bias Voltage. It's commonly used to provide
+	  power to the LCD display and LCD backlight.
+
 config MFD_RT5033
 	tristate "Richtek RT5033 Power Management IC"
 	depends on I2C
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 834f546..5986914 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -235,6 +235,7 @@  obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 obj-$(CONFIG_MFD_HI655X_PMIC)   += hi655x-pmic.o
 obj-$(CONFIG_MFD_DLN2)		+= dln2.o
+obj-$(CONFIG_MFD_RT4831)	+= rt4831.o
 obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
 obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
 
diff --git a/drivers/mfd/rt4831.c b/drivers/mfd/rt4831.c
new file mode 100644
index 00000000..b169781
--- /dev/null
+++ b/drivers/mfd/rt4831.c
@@ -0,0 +1,115 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Richtek Technology Corp.
+ *
+ * Author: ChiYuan Huang <cy_huang@richtek.com>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define RT4831_REG_REVISION	0x01
+#define RT4831_REG_ENABLE	0x08
+#define RT4831_REG_I2CPROT	0x15
+
+#define RICHTEK_VENDOR_ID	0x03
+#define RT4831_VID_MASK		GENMASK(1, 0)
+#define RT4831_RESET_MASK	BIT(7)
+#define RT4831_I2CSAFETMR_MASK	BIT(0)
+
+static const struct mfd_cell rt4831_subdevs[] = {
+	MFD_CELL_OF("rt4831-backlight", NULL, NULL, 0, 0, "richtek,rt4831-backlight"),
+	MFD_CELL_NAME("rt4831-regulator")
+};
+
+static bool rt4831_is_accessible_reg(struct device *dev, unsigned int reg)
+{
+	if (reg >= RT4831_REG_REVISION && reg <= RT4831_REG_I2CPROT)
+		return true;
+	return false;
+}
+
+static const struct regmap_config rt4831_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RT4831_REG_I2CPROT,
+
+	.readable_reg = rt4831_is_accessible_reg,
+	.writeable_reg = rt4831_is_accessible_reg,
+};
+
+static int rt4831_probe(struct i2c_client *client)
+{
+	struct gpio_desc *enable_gpio;
+	struct regmap *regmap;
+	unsigned int chip_id;
+	int ret;
+
+	enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(enable_gpio)) {
+		dev_err(&client->dev, "Failed to get 'enable' GPIO\n");
+		return PTR_ERR(enable_gpio);
+	}
+
+	regmap = devm_regmap_init_i2c(client, &rt4831_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Failed to initialize regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	ret = regmap_read(regmap, RT4831_REG_REVISION, &chip_id);
+	if (ret) {
+		dev_err(&client->dev, "Failed to get H/W revision\n");
+		return ret;
+	}
+
+	if ((chip_id & RT4831_VID_MASK) != RICHTEK_VENDOR_ID) {
+		dev_err(&client->dev, "Chip vendor ID 0x%02x not matched\n", chip_id);
+		return -ENODEV;
+	}
+
+	/*
+	 * Used to prevent the abnormal shutdown.
+	 * If SCL/SDA both keep low for one second to reset HW.
+	 */
+	ret = regmap_update_bits(regmap, RT4831_REG_I2CPROT, RT4831_I2CSAFETMR_MASK,
+				 RT4831_I2CSAFETMR_MASK);
+	if (ret) {
+		dev_err(&client->dev, "Failed to enable I2C safety timer\n");
+		return ret;
+	}
+
+	return devm_mfd_add_devices(&client->dev, PLATFORM_DEVID_AUTO, rt4831_subdevs,
+				    ARRAY_SIZE(rt4831_subdevs), NULL, 0, NULL);
+}
+
+static int rt4831_remove(struct i2c_client *client)
+{
+	struct regmap *regmap = dev_get_regmap(&client->dev, NULL);
+
+	/* Disable WLED and DSV outputs */
+	return regmap_update_bits(regmap, RT4831_REG_ENABLE, RT4831_RESET_MASK, RT4831_RESET_MASK);
+}
+
+static const struct of_device_id __maybe_unused rt4831_of_match[] = {
+	{ .compatible = "richtek,rt4831", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt4831_of_match);
+
+static struct i2c_driver rt4831_driver = {
+	.driver = {
+		.name = "rt4831",
+		.of_match_table = rt4831_of_match,
+	},
+	.probe_new = rt4831_probe,
+	.remove = rt4831_remove,
+};
+module_i2c_driver(rt4831_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_LICENSE("GPL v2");