regulator: add driver for ncv6336 regulator

This commit adds support for the Onsemi NCV6336 buck down converter.

The IC supports interrupts to handle error events, but this driver
does not support it since my board has the interrupt pin unconnected.

Signed-off-by: Fabien Parent <fabien.parent@linaro.org>

drivers/regulator/Kconfig

@@ -934,6 +934,13 @@ config REGULATOR_MTK_DVFSRC
 	  of Mediatek. It allows for voting on regulator state
 	  between multiple users.
 
+config REGULATOR_NCV6336
+	tristate "Onsemi NCV6336 regulator driver"
+	depends on RUST
+	select REGMAP_I2C
+	help
+	  Say y here to support the Onsemi NCV6336 buck converter.
+
 config REGULATOR_PALMAS
 	tristate "TI Palmas PMIC Regulators"
 	depends on MFD_PALMAS

drivers/regulator/Makefile

@@ -111,6 +111,7 @@ obj-$(CONFIG_REGULATOR_MT6370) += mt6370-regulator.o
 obj-$(CONFIG_REGULATOR_MT6380)	+= mt6380-regulator.o
 obj-$(CONFIG_REGULATOR_MT6397)	+= mt6397-regulator.o
 obj-$(CONFIG_REGULATOR_MTK_DVFSRC) += mtk-dvfsrc-regulator.o
+obj-$(CONFIG_REGULATOR_NCV6336) += ncv6336.o
 obj-$(CONFIG_REGULATOR_QCOM_LABIBB) += qcom-labibb-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_REFGEN) += qcom-refgen-regulator.o
 obj-$(CONFIG_REGULATOR_QCOM_RPM) += qcom_rpm-regulator.o

drivers/regulator/ncv6336.rs

@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Driver for the Onsemi Buck Converter NCV6336
+//!
+//! Datasheet: https://www.onsemi.com/pdf/datasheet/ncv6336bm-d.pdf
+
+use kernel::{
+    b_str, c_str, i2c, of,
+    prelude::*,
+    regmap::{self, BitFieldReadOps, BitFieldWriteOps, RawFieldReadOps, RawFieldWriteOps},
+    regulator::{
+        driver::{Config, Desc, Driver, Registration, RegmapHelpers, Regulator, Status, Type},
+        Mode,
+    },
+    sync::Arc,
+};
+use register::*;
+
+kernel::module_i2c_id_table!(I2C_MOD_TABLE, NCV6336_I2C_ID_TABLE);
+kernel::define_i2c_id_table! {NCV6336_I2C_ID_TABLE, (), [
+    (i2c::DeviceId(b_str!("ncv6336")), None),
+]}
+
+kernel::module_of_id_table!(OF_MOD_TABLE, NCV6336_OF_ID_TABLE);
+kernel::define_of_id_table! {NCV6336_OF_ID_TABLE, (), [
+    (of::DeviceId::Compatible(b_str!("onnn,ncv6336")), None),
+]}
+
+kernel::module_i2c_driver! {
+    type: Ncv6336,
+    name: "ncv6336",
+    author: "Fabien Parent <fabien.parent@linaro.org>",
+    license: "GPL",
+}
+
+regmap::define_regmap_field_descs!(FIELD_DESCS, {
+    (pid, 0x3, READ, { value => raw([7:0], ro) }),
+    (rid, 0x4, READ, { value => raw([7:0], ro) }),
+    (fid, 0x5, READ, { value => raw([7:0], ro) }),
+    (progvsel1, 0x10, RW, {
+        voutvsel1 => raw([6:0], rw),
+        envsel1   => bit(7, rw),
+    }),
+    (progvsel0, 0x11, RW, {
+        voutvsel0 => raw([6:0], rw),
+        envsel0   => bit(7, rw),
+    }),
+    (pgood, 0x12, RW, { dischg => bit(4, rw) }),
+    (command, 0x14, RW, {
+        vselgt   => bit(0, rw),
+        pwmvsel1 => bit(6, rw),
+        pwmvsel0 => bit(7, rw),
+    }),
+    (limconf, 0x16, RW, {
+        rearm     => bit(0, rw),
+        rststatus => bit(1, rw),
+        tpwth     => enum([5:4], rw, {
+            Temp83C  = 0x0,
+            Temp94C  = 0x1,
+            Temp105C = 0x2,
+            Temp116C = 0x3,
+        }),
+        ipeak     => enum([7:6], rw, {
+            Peak3p5A = 0x0,
+            Peak4p0A = 0x1,
+            Peak4p5A = 0x2,
+            Peak5p0A = 0x3,
+        }),
+    })
+});
+
+static NCV6336_DESC: Desc = Desc::new::<Ncv6336>(c_str!("ncv6336"), Type::Voltage)
+    .with_owner(&THIS_MODULE)
+    .with_active_discharge(
+        pgood::addr(),
+        pgood::dischg::mask(),
+        pgood::dischg::mask(),
+        0,
+    )
+    .with_csel(
+        limconf::addr(),
+        limconf::ipeak::mask(),
+        &[3500000, 4000000, 4500000, 5000000],
+    )
+    .with_enable(
+        progvsel0::addr(),
+        progvsel0::envsel0::mask(),
+        progvsel0::envsel0::mask(),
+        0,
+    )
+    .with_linear_mapping(
+        progvsel0::addr(),
+        progvsel0::voutvsel0::mask(),
+        600000,
+        6250,
+        128,
+        0,
+    );
+
+type RegulatorData = kernel::device::Data<Registrations, (), ()>;
+
+struct Registrations {
+    fields: regmap::Fields<{ FIELD_DESCS.count() }>,
+    regulator: Option<Registration>,
+}
+
+struct Ncv6336;
+impl i2c::Driver for Ncv6336 {
+    type Data = Arc<RegulatorData>;
+
+    kernel::driver_i2c_id_table!(NCV6336_I2C_ID_TABLE);
+    kernel::driver_of_id_table!(NCV6336_OF_ID_TABLE);
+
+    fn probe(client: &mut i2c::Client) -> Result<Self::Data> {
+        let config = regmap::Config::<AccessOps>::new(8, 8)
+            .with_max_register(0x16)
+            .with_cache_type(regmap::CacheType::RbTree);
+        let regmap = Arc::try_new(regmap::Regmap::init_i2c(client, &config))?;
+        let mut fields = regmap.alloc_fields(&FIELD_DESCS)?;
+
+        let pid = pid::value::read(&mut fields)?;
+        let rid = rid::value::read(&mut fields)?;
+        let fid = fid::value::read(&mut fields)?;
+
+        let data: Arc<RegulatorData> = kernel::new_device_data!(
+            Registrations {
+                fields,
+                regulator: None
+            },
+            (),
+            (),
+            "Ncv6336::Registrations"
+        )?
+        .into();
+
+        let config = Config::new(client, data.clone()).with_regmap(regmap.clone());
+        let reg = Registration::register(client, &NCV6336_DESC, config)?;
+        data.registrations().ok_or(EINVAL)?.regulator = Some(reg);
+
+        dev_info!(client, "PID: {pid:#x}, RID: {rid:#x}, FID: {fid:#x}");
+
+        Ok(data)
+    }
+}
+
+#[vtable]
+impl Driver for Ncv6336 {
+    type Data = Arc<RegulatorData>;
+
+    fn list_voltage(reg: &Regulator, selector: u32) -> Result<i32> {
+        reg.list_voltage_linear(selector)
+    }
+
+    fn enable(reg: &Regulator) -> Result {
+        reg.enable_regmap()
+    }
+
+    fn disable(reg: &Regulator) -> Result {
+        reg.disable_regmap()
+    }
+
+    fn is_enabled(reg: &Regulator) -> Result<bool> {
+        reg.is_enabled_regmap()
+    }
+
+    fn set_active_discharge(reg: &Regulator, enable: bool) -> Result {
+        reg.set_active_discharge_regmap(enable)
+    }
+
+    fn set_current_limit(reg: &Regulator, min_ua: i32, max_ua: i32) -> Result {
+        reg.set_current_limit_regmap(min_ua, max_ua)
+    }
+
+    fn get_current_limit(reg: &Regulator) -> Result<i32> {
+        reg.get_current_limit_regmap()
+    }
+
+    fn set_voltage_sel(reg: &Regulator, selector: u32) -> Result {
+        reg.set_voltage_sel_regmap(selector)
+    }
+
+    fn get_voltage_sel(reg: &Regulator) -> Result<i32> {
+        reg.get_voltage_sel_regmap()
+    }
+
+    fn set_mode(reg: &Regulator, mode: Mode) -> Result {
+        let data = reg.data::<Self::Data>();
+        let fields = &mut data.registrations().ok_or(EINVAL)?.fields;
+
+        match mode {
+            Mode::Normal => command::pwmvsel0::clear(fields),
+            Mode::Fast => command::pwmvsel0::set(fields),
+            _ => Err(ENOTSUPP),
+        }
+    }
+
+    fn get_mode(reg: &Regulator) -> Mode {
+        if let Some(mut registrations) = reg.data::<Self::Data>().registrations() {
+            match command::pwmvsel0::is_set(&mut registrations.fields) {
+                Ok(true) => Mode::Fast,
+                Ok(false) => Mode::Normal,
+                Err(_) => Mode::Invalid,
+            }
+        } else {
+            Mode::Invalid
+        }
+    }
+
+    fn get_status(reg: &Regulator) -> Result<Status> {
+        if !Self::is_enabled(reg)? {
+            return Ok(Status::Off);
+        }
+
+        Ok(Self::get_mode(reg).into())
+    }
+
+    fn set_suspend_voltage(reg: &Regulator, uv: i32) -> Result {
+        let data = reg.data::<Self::Data>();
+        let fields = &mut data.registrations().ok_or(EINVAL)?.fields;
+
+        let quot = (uv - 600000) / 6250;
+        let rem = (uv - 600000) % 6250;
+        let selector = if rem > 0 { quot + 1 } else { quot };
+
+        progvsel1::voutvsel1::write(fields, selector as _)
+    }
+
+    fn set_suspend_enable(reg: &Regulator) -> Result {
+        let data = reg.data::<Self::Data>();
+        let fields = &mut data.registrations().ok_or(EINVAL)?.fields;
+
+        progvsel1::envsel1::set(fields)?;
+        command::vselgt::clear(fields)
+    }
+
+    fn set_suspend_disable(reg: &Regulator) -> Result {
+        let data = reg.data::<Self::Data>();
+        let fields = &mut data.registrations().ok_or(EINVAL)?.fields;
+
+        progvsel1::envsel1::clear(fields)?;
+        command::vselgt::set(fields)
+    }
+
+    fn set_suspend_mode(reg: &Regulator, mode: Mode) -> Result {
+        let data = reg.data::<Self::Data>();
+        let fields = &mut data.registrations().ok_or(EINVAL)?.fields;
+
+        match mode {
+            Mode::Normal => command::pwmvsel1::clear(fields),
+            Mode::Fast => command::pwmvsel1::set(fields),
+            _ => Err(ENOTSUPP),
+        }
+    }
+}