Re: [PATCH v5 4/5] mfd: sm5703: Add support for SM5703 MFD

From: Markuss Broks
Date: Sat Jul 09 2022 - 07:07:21 EST

Hi Lee,

On 6/15/22 00:32, Lee Jones wrote:
On Sat, 23 Apr 2022, Markuss Broks wrote:

Silicon Mitus SM5703 is a multi-function device, meant to be
Please avoid using the term MFD.

How is the device described in the data-sheet?
I don't have a data-sheet for this device. The only reference I have is downstream Linux driver. Maybe a better way to call it would be PMIC?

What do you mean by "meant to be"?
"designed to be", it appears that this part is almost exclusively used by Samsung in its mobile phones.

used in mobile devices. It has several modules: LDO, BUCK regulators,
Modules or functions?

Some of "modules" are quite separate, so I decided to call it that way. How should it be called?


charger circuit, flash LED driver, a fuel gauge for monitoring the battery
and a MUIC USB switcher. The MUIC and fuel gauge parts are separate in that
they use separate i2c lines to communicate with the device, while charger
"I2C"

circuit, LED driver and regulators are on the main i2c line the device is
controlled with.

Signed-off-by: Markuss Broks <markuss.broks@xxxxxxxxx>
---
MAINTAINERS | 8 +++
drivers/mfd/Kconfig | 13 +++++
drivers/mfd/Makefile | 1 +
drivers/mfd/sm5703.c | 78 +++++++++++++++++++++++++++
include/linux/mfd/sm5703.h | 105 +++++++++++++++++++++++++++++++++++++
5 files changed, 205 insertions(+)
create mode 100644 drivers/mfd/sm5703.c
create mode 100644 include/linux/mfd/sm5703.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 6157e706ed02..6125ed1a3be4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18172,6 +18172,14 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev
F: include/linux/srcu*.h
F: kernel/rcu/srcu*.c
+SM5703 MFD DRIVER
+M: Markuss Broks <markuss.broks@xxxxxxxxx>
+S: Maintained
+F: Documentation/devicetree/bindings/mfd/siliconmitus,sm5703.yaml
+F: Documentation/devicetree/bindings/regulator/siliconmitus,sm5703-regulator.yaml
+F: drivers/mfd/sm5703.c
+F: drivers/regulator/sm5703-regulator.c
+
SMACK SECURITY MODULE
M: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
L: linux-security-module@xxxxxxxxxxxxxxx
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 3b59456f5545..c13a99ceae99 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1237,6 +1237,19 @@ config MFD_SM501
interface. The device may be connected by PCI or local bus with
varying functions enabled.
+config MFD_SM5703
+ tristate "Silicon Mitus SM5703 MFD"
+ depends on I2C
+ depends on OF
+ select MFD_CORE
+ select REGMAP_I2C
+ help
+ This is the core driver for the Silicon Mitus SM5703 multi-function
Please drop the MFD term, as above.

+ device. This device is meant to be used in phones and it has numerous
"meant to be"?

+ modules, including LED controller, regulators, fuel gauge, MUIC and
Either "an LED controller" or "LED controllers"

Same with "charger circuit" below.

+ charger circuit. It also support muxing a serial interface over USB
"supports"

What kind of serial?
UART as a standard Samsung debug port interface (619K Ohm resistor between data lines is Samsung's debug cable).

+ data lines.
+
config MFD_SM501_GPIO
bool "Export GPIO via GPIO layer"
depends on MFD_SM501 && GPIOLIB
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 858cacf659d6..ca8b86736a36 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -275,3 +275,4 @@ rsmu-i2c-objs := rsmu_core.o rsmu_i2c.o
rsmu-spi-objs := rsmu_core.o rsmu_spi.o
obj-$(CONFIG_MFD_RSMU_I2C) += rsmu-i2c.o
obj-$(CONFIG_MFD_RSMU_SPI) += rsmu-spi.o
+obj-$(CONFIG_MFD_SM5703) += sm5703.o
diff --git a/drivers/mfd/sm5703.c b/drivers/mfd/sm5703.c
new file mode 100644
index 000000000000..7f9838149051
--- /dev/null
+++ b/drivers/mfd/sm5703.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/sm5703.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+static const struct mfd_cell sm5703_devs[] = {
+ { .name = "sm5703-regulator", },
+};
Where are the rest of the child drivers?

+static const struct regmap_config sm5703_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
Tabbing looks odd. Just use a space.

+};
+
+static int sm5703_i2c_probe(struct i2c_client *i2c,
+ const struct i2c_device_id *id)
+{
+ struct sm5703_dev *sm5703;
+ struct device *dev = &i2c->dev;
+ unsigned int dev_id;
+ int ret;
+
+ sm5703 = devm_kzalloc(dev, sizeof(*sm5703), GFP_KERNEL);
+ if (!sm5703)
+ return -ENOMEM;
+
+ i2c_set_clientdata(i2c, sm5703);
+ sm5703->dev = dev;
+
+ sm5703->regmap = devm_regmap_init_i2c(i2c, &sm5703_regmap_config);
+ if (IS_ERR(sm5703->regmap))
+ return dev_err_probe(dev, PTR_ERR(sm5703->regmap),
+ "Failed to allocate the register map\n");
+
+ sm5703->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(sm5703->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(sm5703->reset_gpio), "Cannot get reset GPIO\n");
+
+ gpiod_set_value_cansleep(sm5703->reset_gpio, 1);
+ msleep(20);
+
+ ret = regmap_read(sm5703->regmap, SM5703_DEVICE_ID, &dev_id);
+ if (ret)
+ return dev_err_probe(dev, -ENODEV, "Device not found\n");
+
+ ret = devm_mfd_add_devices(sm5703->dev, -1, sm5703_devs,
Not -1. Please use the defines provided.

+ ARRAY_SIZE(sm5703_devs), NULL, 0, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to add child devices\n");
+
+ return 0;
+}
+
+static const struct of_device_id sm5703_of_match[] = {
+ { .compatible = "siliconmitus,sm5703", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sm5703_of_match);
+
+static struct i2c_driver sm5703_driver = {
+ .driver = {
+ .name = "sm5703",
+ .of_match_table = sm5703_of_match,
+ },
+ .probe = sm5703_i2c_probe,
+};
+module_i2c_driver(sm5703_driver);
+
+MODULE_DESCRIPTION("Silicon Mitus SM5703 multi-function device driver");
There is no such thing as an MFD.

+MODULE_AUTHOR("Markuss Broks <markuss.broks@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/sm5703.h b/include/linux/mfd/sm5703.h
new file mode 100644
index 000000000000..c62affa0d3f1
--- /dev/null
+++ b/include/linux/mfd/sm5703.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SM5703_H
+#define _SM5703_H
+
+struct sm5703_dev {
+ struct device *dev;
+ struct regmap *regmap;
+ struct gpio_desc *reset_gpio;
+};
+
+// Regulator-related defines
No C++ style comments.

+#define SM5703_REG_LDO1 0x1A
I'd drop the REG parts from these.

What are these registers called in the data-sheet?
No data-sheet, sadly.

+#define SM5703_REG_LDO2 0x1B
+#define SM5703_REG_LDO3 0x1C
+#define SM5703_LDO_EN BIT(3)
Some people like to space out the bits to differentiate them from the
register addresses.

+#define SM5703_LDO_VOLT_MASK 0x7
Please keep the bit length consistent, so 0x07 here if these are Byte
length registers.

+#define SM5703_BUCK_VOLT_MASK 0x1F
+#define SM5703_REG_USBLDO12 0x1C
+#define SM5703_REG_EN_USBLDO1 BIT(6)
+#define SM5703_REG_EN_USBLDO2 BIT(7)
+#define SM5703_REG_BUCK 0x1D
Please place these in order.

+#define SM5703_REG_EN_BUCK BIT(6)
+#define SM5703_USBLDO_MICROVOLT 4800000
+#define SM5703_VBUS_MICROVOLT 5000000
+
+// Fuel-Gauge-related defines
+
+#define SM5703_FG_REG_DEVICE_ID 0x00
+#define SM5703_FG_REG_CNTL 0x01
+#define SM5703_FG_REG_INTFG 0x02
+#define SM5703_FG_REG_INTFG_MASK 0x03
+#define SM5703_FG_REG_STATUS 0x04
+#define SM5703_FG_REG_SOC 0x05
+#define SM5703_FG_REG_OCV 0x06
+#define SM5703_FG_REG_VOLTAGE 0x07
+#define SM5703_FG_REG_CURRENT 0x08
+#define SM5703_FG_REG_TEMPERATURE 0x09
+#define SM5703_FG_REG_CURRENT_EST 0x85
+#define SM5703_FG_REG_FG_OP_STATUS 0x10
+
+// Flash LED driver-related defines
+
+#define SM5703_FLEDCNTL1 0x14
+#define SM5703_FLEDCNTL2 0x15
+#define SM5703_FLEDCNTL3 0x16
+#define SM5703_FLEDCNTL4 0x17
+#define SM5703_FLEDCNTL5 0x18
+#define SM5703_FLEDCNTL6 0x19
+
+#define SM5703_FLEDEN_MASK 0x03
+#define SM5703_FLEDEN_DISABLE 0x00
+#define SM5703_FLEDEN_MOVIE_MODE 0x01
+#define SM5703_FLEDEN_FLASH_MODE 0x02
+#define SM5703_FLEDEN_EXTERNAL 0x03
+
+#define SM5703_IFLED_MASK 0x1F
+#define SM5703_IMLED_MASK 0x1F
+
+// Charger-related, IRQ and device ID defines
+
+#define SM5703_REG_CNTL 0x0C
+#define SM5703_VBUSCNTL 0x0D
+#define SM5703_CHGCNTL1 0x0E
+#define SM5703_CHGCNTL2 0x0F
+#define SM5703_CHGCNTL3 0x10
+#define SM5703_CHGCNTL4 0x11
+#define SM5703_CHGCNTL5 0x12
+#define SM5703_CHGCNTL6 0x13
+#define SM5703_OTGCURRENTCNTL 0x60
+#define SM5703_Q3LIMITCNTL 0x66
+#define SM5703_DEVICE_ID 0x1E
+#define SM5703_OPERATION_MODE 0x07
+#define SM5703_OPERATION_MODE_MASK 0x07
+
+#define SM5703_OPERATION_MODE_SUSPEND 0x00
+#define SM5703_OPERATION_MODE_CHARGING_OFF 0x04
+#define SM5703_OPERATION_MODE_CHARGING_ON 0x05
+#define SM5703_OPERATION_MODE_FLASH_BOOST_MODE 0x06
+#define SM5703_OPERATION_MODE_USB_OTG_MODE 0x07
+
+#define SM5703_BSTOUT 0x0F
+#define SM5703_BSTOUT_MASK 0x0F
+#define SM5703_BSTOUT_SHIFT 0
+
+#define SM5703_BSTOUT_4P5 0x05
+#define SM5703_BSTOUT_5P0 0x0A
+#define SM5703_BSTOUT_5P1 0x0B
+
+#define SM5703_IRQ_STATUS1 0x08
+#define SM5703_IRQ_STATUS2 0x09
+#define SM5703_IRQ_STATUS3 0x0A
+#define SM5703_IRQ_STATUS4 0x0B
+#define SM5703_IRQ_STATUS5 0x6B
+
+#define SM5703_STATUS1_OTGFAIL 0x80
+#define SM5703_STATUS3_DONE 0x08
+#define SM5703_STATUS3_TOPOFF 0x04
+#define SM5703_STATUS3_CHGON 0x01
+#define SM5703_STATUS5_VBUSOVP 0x80
+#define SM5703_STATUS5_VBUSUVLO 0x40
+#define SM5703_STATUS5_VBUSOK 0x20
+
+#endif
- Markuss