mfd: rt4831: Adds support for Richtek RT4831

From: ChiYuan Huang <[email protected]>

Adds DT binding document for Richtek RT4831 backlight.

Signed-off-by ChiYuan Huang <[email protected]>

From: ChiYuan Huang <[email protected]>

Adds support for Richtek RT4831 backlight.

Signed-off-by ChiYuan Huang <[email protected]>

---
since v6
- Fix Kconfig typo.
- Remove internal mutex lock.
- Add the prefix for max brightness.
- rename init_device_properties to parse_backlight_properties.
- Remove some warning message if default value is adopted.
- Add backlight property scale to LINEAR mapping.
- Fix regmap get to check NULL not IS_ERR.

---
 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

drivers/video/backlight/Kconfig +0 -0

index d83c87b..de96441 100644

Quoted 29 lines

From: ChiYuan Huang <[email protected]>

Adds support for Richtek RT4831 backlight.

Signed-off-by ChiYuan Huang <[email protected]>

---
since v6
- Fix Kconfig typo.
- Remove internal mutex lock.
- Add the prefix for max brightness.
- rename init_device_properties to parse_backlight_properties.
- Remove some warning message if default value is adopted.
- Add backlight property scale to LINEAR mapping.
- Fix regmap get to check NULL not IS_ERR.

---
 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

drivers/video/backlight/Kconfig +0 -0

index d83c87b..de96441 100644
@@ -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.
 

drivers/video/backlight/Kconfig config BACKLIGHT_QCOM_WLED · line 297

Quoted 6 lines

drivers/video/backlight/Kconfig +6 -0

+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

Nitpicking but I was expecting the original typo be converted to "commonly".

With that addressed:

Reviewed-by Daniel Thompson <[email protected]>

Daniel.

From: ChiYuan Huang <[email protected]>

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

Signed-off-by ChiYuan Huang <[email protected]>

---
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

drivers/mfd/Kconfig +10 -0

index b74efa4..3f43834 100644
@@ -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

drivers/mfd/Makefile +1 -0

index 834f546..5986914 100644
@@ -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
 

drivers/mfd/rt4831.c new file +115 -1

new file mode 100644
index 00000000..b169781
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Richtek Technology Corp.
+ *
+ * Author: ChiYuan Huang <[email protected]>
+ */
+
+#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 <[email protected]>");
+MODULE_LICENSE("GPL v2");
--

2.7.4

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

cy_huang <[email protected]> 於 2021年3月28日 週日 下午11:24寫道：

Quoted 37 lines

From: ChiYuan Huang <[email protected]>

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

Signed-off-by ChiYuan Huang <[email protected]>

---
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

Quoted 4 lines · ChiYuan Huang

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

Couple of things:

First, if you think a patch had fallen through the gaps, which does happen sometimes, it is generally considered acceptable to submit a [RESEND] ~2 weeks after the initial submission. FYI: This was such a patch. It was not on, or had fallen off of my radar for some reason.

Secondly, we are really late in the release cycle. -rc8 has just been released. Quite a few maintainers slow down at ~-rc6. Particularly for new drivers.

No need to resubmit this driver this time. It is now on my to-review list and I will tend to it shortly.

Thanks for your patience.

Quoted 18 lines · Lee Jones

Quoted 4 lines · ChiYuan Huang

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

Couple of things:

First, if you think a patch had fallen through the gaps, which does happen sometimes, it is generally considered acceptable to submit a [RESEND] ~2 weeks after the initial submission. FYI: This was such a patch. It was not on, or had fallen off of my radar for some reason.

Secondly, we are really late in the release cycle. -rc8 has just been released. Quite a few maintainers slow down at ~-rc6. Particularly for new drivers.

Quoted 4 lines

No need to resubmit this driver this time. It is now on my to-review list and I will tend to it shortly.

Thanks for your patience.

Also you are missing a DT review on patch 4.

Quoted 21 lines · Lee Jones

Quoted 19 lines · ChiYuan Huang

Quoted 5 lines

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

Couple of things:

First, if you think a patch had fallen through the gaps, which does happen sometimes, it is generally considered acceptable to submit a [RESEND] ~2 weeks after the initial submission. FYI: This was such a patch. It was not on, or had fallen off of my radar for some reason.

Secondly, we are really late in the release cycle. -rc8 has just been released. Quite a few maintainers slow down at ~-rc6. Particularly for new drivers.

Quoted 6 lines

Quoted 4 lines

No need to resubmit this driver this time. It is now on my to-review list and I will tend to it shortly.

Thanks for your patience.

Also you are missing a DT review on patch 4.

... looks like you forgot to Cc them!

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services

Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Lee Jones <[email protected]> 於 2021年4月19日 週一 下午3:24寫道：

Quoted 26 lines · Lee Jones

Quoted 24 lines · Lee Jones

Quoted 22 lines · ChiYuan Huang

Quoted 5 lines

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

Couple of things:

First, if you think a patch had fallen through the gaps, which does happen sometimes, it is generally considered acceptable to submit a [RESEND] ~2 weeks after the initial submission. FYI: This was such a patch. It was not on, or had fallen off of my radar for some reason.

Secondly, we are really late in the release cycle. -rc8 has just been released. Quite a few maintainers slow down at ~-rc6. Particularly for new drivers.

No need to resubmit this driver this time. It is now on my to-review list and I will tend to it shortly.

Quoted 6 lines

Quoted 3 lines

Quoted 1 line

Thanks for your patience.

Also you are missing a DT review on patch 4.

... looks like you forgot to Cc them!

Yap, really. I''ll resend patch 4 and cc them. Thx.

Quoted 5 lines

--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services

Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Hi, Lee:

ChiYuan Huang <[email protected]> 於 2021年4月19日 週一 下午5:55寫道：

Quoted 30 lines

Lee Jones <[email protected]> 於 2021年4月19日 週一 下午3:24寫道：

Quoted 28 lines · Lee Jones

Quoted 26 lines · Lee Jones

Quoted 23 lines · ChiYuan Huang

Quoted 5 lines

Hi, Linux mfd reviewers:
It's been three weeks not to get any response from you.
Is there something wrong about this mfd patch?
If yes, please feel free to let me know.

Couple of things:

First, if you think a patch had fallen through the gaps, which does happen sometimes, it is generally considered acceptable to submit a [RESEND] ~2 weeks after the initial submission. FYI: This was such a patch. It was not on, or had fallen off of my radar for some reason.

Secondly, we are really late in the release cycle. -rc8 has just been released. Quite a few maintainers slow down at ~-rc6. Particularly for new drivers.

No need to resubmit this driver this time. It is now on my to-review list and I will tend to it shortly.

Thanks for your patience.

Quoted 5 lines

Quoted 4 lines

Quoted 1 line

Also you are missing a DT review on patch 4.

... looks like you forgot to Cc them!

Yap, really. I''ll resend patch 4 and cc them. Thx.

Should I resend the patch and loop DT reviewers?