[U-Boot] [PATCH v2 1/2] power: regulator: add driver for the FAN53555 family

Lukasz Majewski lukma at denx.de
Thu Nov 23 09:57:00 UTC 2017


Hi Philipp,

> This adds a driver for the FAN53555 family of regulators.
> 
> While these devices support a 'normal' and 'suspend' mode (controlled
> via an external pin) to switch between two programmable voltages, this
> incarnation of the driver assumes that the device is always operating
> in 'normal' mode.
> 
> Only setting/reading the programmed voltage is supported at this time
> and the following device functionality remains unsupported:
>   - switching the selected voltage (via a GPIO)
>   - disabling the voltage output via software-control
> This matches the functionality of the Linux driver.
> 
> Tested on a RK3399-Q7 (with 'option 5' devices): setting voltages from
> the U-Boot shell and verifying output voltages on the board.
> 
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> Tested-by: Klaus Goger <klaus.goger at theobroma-systems.com>
> 
> ---
> 
> Changes in v2:
> - adapted documentation on the device-tree binding from Linux
> 
>  doc/device-tree-bindings/regulator/fan53555.txt |  23 +++
>  drivers/power/regulator/Kconfig                 |  14 ++
>  drivers/power/regulator/Makefile                |   1 +
>  drivers/power/regulator/fan53555.c              | 255
> ++++++++++++++++++++++++ 4 files changed, 293 insertions(+)
>  create mode 100644 doc/device-tree-bindings/regulator/fan53555.txt
>  create mode 100644 drivers/power/regulator/fan53555.c
> 
> diff --git a/doc/device-tree-bindings/regulator/fan53555.txt
> b/doc/device-tree-bindings/regulator/fan53555.txt new file mode 100644
> index 0000000..b183738
> --- /dev/null
> +++ b/doc/device-tree-bindings/regulator/fan53555.txt
> @@ -0,0 +1,23 @@
> +Binding for Fairchild FAN53555 regulators
> +
> +Required properties:
> +  - compatible: "fcs,fan53555"
> +  - reg: I2C address
> +
> +Optional properties:
> +  - fcs,suspend-voltage-selector: declare which of the two available
> +		voltage selector registers should be used for the
> suspend
> +		voltage. The other one is used for the runtime
> voltage setting
> +		Possible values are either <0> or <1>
> +  - vin-supply: regulator supplying the vin pin
> +
> +Example:
> +
> +	regulator at 40 {
> +		compatible = "fcs,fan53555";
> +		regulator-name = "fan53555";
> +		regulator-min-microvolt = <1000000>;
> +		regulator-max-microvolt = <1800000>;
> +		vin-supply = <&parent_reg>;
> +		fcs,suspend-voltage-selector = <1>;
> +	};
> diff --git a/drivers/power/regulator/Kconfig
> b/drivers/power/regulator/Kconfig index 8892fa1..c26a765 100644
> --- a/drivers/power/regulator/Kconfig
> +++ b/drivers/power/regulator/Kconfig
> @@ -69,6 +69,20 @@ config DM_REGULATOR_MAX77686
>  	features for REGULATOR MAX77686. The driver implements
> get/set api for: value, enable and mode.
>  
> +config DM_REGULATOR_FAN53555
> +	bool "Enable Driver Model for REGULATOR FAN53555"
> +	depends on DM_REGULATOR && DM_I2C
> +	---help---
> +	This config enables implementation of driver-model regulator
> uclass
> +	features for the FAN53555 regulator. The FAN53555 is a
> (family of)
> +	single-output regulators that supports transitioning between
> two
> +	different output voltages based on an voltage selection pin.
> +
> +	The driver implements a get/set api for the voltage of the
> 'normal
> +	mode' voltage only. Switching to 'suspend mode' (i.e. the
> alternate
> +	voltage), disabling output via software, or switching the
> mode is
> +	not supported by this driver (at this time).
> +
>  config DM_REGULATOR_FIXED
>  	bool "Enable Driver Model for REGULATOR Fixed value"
>  	depends on DM_REGULATOR
> diff --git a/drivers/power/regulator/Makefile
> b/drivers/power/regulator/Makefile index 6c149a9..21040ea 100644
> --- a/drivers/power/regulator/Makefile
> +++ b/drivers/power/regulator/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_REGULATOR_AS3722)	+=
> as3722_regulator.o obj-$(CONFIG_DM_REGULATOR_MAX77686) += max77686.o
>  obj-$(CONFIG_DM_REGULATOR_PFUZE100) += pfuze100.o
>  obj-$(CONFIG_REGULATOR_PWM) += pwm_regulator.o
> +obj-$(CONFIG_$(SPL_)DM_REGULATOR_FAN53555) += fan53555.o
>  obj-$(CONFIG_$(SPL_)DM_REGULATOR_FIXED) += fixed.o
>  obj-$(CONFIG_$(SPL_)DM_REGULATOR_GPIO) += gpio-regulator.o
>  obj-$(CONFIG_REGULATOR_RK8XX) += rk8xx.o
> diff --git a/drivers/power/regulator/fan53555.c
> b/drivers/power/regulator/fan53555.c new file mode 100644
> index 0000000..3f0b4e9
> --- /dev/null
> +++ b/drivers/power/regulator/fan53555.c
> @@ -0,0 +1,255 @@
> +/*
> + * (C) 2017 Theobroma Systems Design und Consulting GmbH
> + *
> + * SPDX-License-Identifier:     GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <bitfield.h>
> +#include <errno.h>
> +#include <dm.h>
> +#include <fdtdec.h>
> +#include <i2c.h>
> +#include <asm/gpio.h>
> +#include <power/pmic.h>
> +#include <power/regulator.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +/*
> + * The voltage ramp (i.e. minimum voltage and step) is defined by the
> + * combination of 2 nibbles: DIE_ID and DIE_REV.
> + *
> + * See http://www.onsemi.com/pub/Collateral/FAN53555-D.pdf for
> details.
> + */
> +static const struct {
> +	u8 die_id;
> +	u8 die_rev;
> +	u32 vsel_min;
> +	u32 vsel_step;
> +} ic_types[] = {
> +	{ 0x0, 0x3, 600000, 10000 },  /* Option 00 */
> +	{ 0x0, 0xf, 800000, 10000 },  /* Option 13 */
> +	{ 0x0, 0xc, 600000, 12500 },  /* Option 23 */
> +	{ 0x1, 0x3, 600000, 10000 },  /* Option 01 */
> +	{ 0x3, 0x3, 600000, 10000 },  /* Option 03 */
> +	{ 0x4, 0xf, 603000, 12826 },  /* Option 04 */
> +	{ 0x5, 0x3, 600000, 10000 },  /* Option 05 */
> +	{ 0x8, 0x1, 600000, 10000 },  /* Option 08 */
> +	{ 0x8, 0xf, 600000, 10000 },  /* Option 08 */
> +	{ 0xc, 0xf, 603000, 12826 },  /* Option 09 */
> +};
> +
> +/* I2C-accessible byte-sized registers */
> +enum {
> +	/* Voltage setting */
> +	FAN53555_VSEL0 = 0x00,
> +	FAN53555_VSEL1,
> +	/* Control register */
> +	FAN53555_CONTROL,
> +	/* IC Type */
> +	FAN53555_ID1,
> +	/* IC mask version */
> +	FAN53555_ID2,
> +	/* Monitor register */
> +	FAN53555_MONITOR,
> +};
> +
> +struct fan53555_platdata {
> +	/* Voltage setting register */
> +	unsigned int vol_reg;
> +	unsigned int sleep_reg;
> +
> +};
> +
> +struct fan53555_priv {
> +	/* IC Vendor */
> +	unsigned int vendor;
> +	/* IC Type and Rev */
> +	unsigned int die_id;
> +	unsigned int die_rev;
> +	/* Voltage range and step(linear) */
> +	unsigned int vsel_min;
> +	unsigned int vsel_step;
> +	/* Voltage slew rate limiting */
> +	unsigned int slew_rate;
> +	/* Sleep voltage cache */
> +	unsigned int sleep_vol_cache;
> +};
> +
> +static int fan53555_write(struct udevice *dev, uint reg, u8 *buff,
> int len) +{
> +	int ret;
> +
> +	ret = dm_i2c_write(dev, reg, buff, len);
> +	if (ret) {
> +		debug("%s: %s() failed to read reg %d\n",
> +		      dev->name, __func__, reg);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int fan53555_read(struct udevice *dev, uint reg, u8 *buff,
> int len) +{
> +	int ret;
> +
> +	ret = dm_i2c_read(dev, reg, buff, len);
> +	if (ret) {
> +		debug("%s: %s() failed to read reg %d\n",
> +		      dev->name, __func__, reg);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int fan53555_regulator_ofdata_to_platdata(struct udevice *dev)
> +{
> +	struct fan53555_platdata *dev_pdata = dev_get_platdata(dev);
> +	struct dm_regulator_uclass_platdata *uc_pdata;
> +	u32 sleep_vsel;
> +
> +	uc_pdata = dev_get_uclass_platdata(dev);
> +	if (!uc_pdata)
> +		return -ENXIO;
> +
> +	/* This is a buck regulator */
> +	uc_pdata->type = REGULATOR_TYPE_BUCK;
> +
> +	sleep_vsel = dev_read_u32_default(dev,
> "fcs,suspend-voltage-selector",
> +					  FAN53555_VSEL1);
> +
> +	/*
> +	 * Depending on the device-tree settings, the 'normal mode'
> +	 * voltage is either controlled by VSEL0 or VSEL1.
> +	 */
> +	switch (sleep_vsel) {
> +	case FAN53555_VSEL0:
> +		dev_pdata->sleep_reg = FAN53555_VSEL0;
> +		dev_pdata->vol_reg = FAN53555_VSEL1;
> +		break;
> +	case FAN53555_VSEL1:
> +		dev_pdata->sleep_reg = FAN53555_VSEL1;
> +		dev_pdata->vol_reg = FAN53555_VSEL0;
> +		break;
> +	default:
> +		pr_err("%s: invalid vsel id %d\n", dev->name,
> sleep_vsel);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int fan53555_regulator_get_value(struct udevice *dev)
> +{
> +	struct fan53555_platdata *pdata = dev_get_platdata(dev);
> +	struct fan53555_priv *priv = dev_get_priv(dev);
> +	u8 vol;
> +	int voltage;
> +
> +	/* We only support a single voltage selector (i.e. 'normal'
> mode). */
> +	fan53555_read(dev, pdata->vol_reg, &vol, 1);
> +	voltage = priv->vsel_min + (vol & 0x3f) * priv->vsel_step;
> +
> +	debug("%s: %d uV\n", __func__, voltage);
> +	return voltage;
> +}
> +
> +static int fan53555_regulator_set_value(struct udevice *dev, int uV)
> +{
> +	struct fan53555_platdata *pdata = dev_get_platdata(dev);
> +	struct fan53555_priv *priv = dev_get_priv(dev);
> +	u8 vol, oldbits, newbits;
> +
> +	vol = (uV - priv->vsel_min) / priv->vsel_step;
> +	fan53555_read(dev, pdata->vol_reg, &oldbits, 1);
> +	newbits = bitfield_replace(oldbits, 0, 6, vol);
> +	fan53555_write(dev, pdata->vol_reg, &newbits, 1);
> +
> +	debug("%s: uV=%d; reg %d: %02x -> %02x\n",
> +	      __func__, uV, pdata->vol_reg, oldbits, newbits);
> +
> +	return 0;
> +}
> +
> +static int fan53555_voltages_setup(struct udevice *dev)
> +{
> +	struct fan53555_priv *priv = dev_get_priv(dev);
> +	struct dm_regulator_uclass_platdata *uc_pdata;
> +	int i;
> +
> +	uc_pdata = dev_get_uclass_platdata(dev);
> +	if (!uc_pdata)
> +		return -ENXIO;
> +
> +	/* Init voltage range and step */
> +	for (i = 0; i < ARRAY_SIZE(ic_types); ++i) {
> +		if (ic_types[i].die_id != priv->die_id)
> +			continue;
> +
> +		if (ic_types[i].die_rev != priv->die_rev)
> +			continue;
> +
> +		priv->vsel_min = ic_types[i].vsel_min;
> +		priv->vsel_step = ic_types[i].vsel_step;
> +
> +		return 0;
> +	}
> +
> +	pr_err("%s: %s: die id %d rev %d not supported!\n",
> +	       dev->name, __func__, priv->die_id, priv->die_rev);
> +	return -EINVAL;
> +}
> +
> +enum {
> +	DIE_ID_SHIFT = 0,
> +	DIE_ID_WIDTH = 4,
> +	DIE_REV_SHIFT = 0,
> +	DIE_REV_WIDTH = 4,
> +};
> +
> +
> +static int fan53555_probe(struct udevice *dev)
> +{
> +	struct fan53555_priv *priv = dev_get_priv(dev);
> +	u8 id1, id2;
> +
> +	/* read chip id: vendor, die-id and die-revision */
> +	fan53555_read(dev, FAN53555_ID1, &id1, 1);
> +	fan53555_read(dev, FAN53555_ID2, &id2, 1);
> +
> +	priv->vendor = bitfield_extract(id1, 5, 3);
> +	priv->die_id = id1 & GENMASK(3, 0);
> +	priv->die_rev = id2 & GENMASK(3, 0);
> +
> +	if (fan53555_voltages_setup(dev) < 0)
> +		return -ENODATA;
> +
> +	debug("%s: FAN53555 option %d rev %d detected\n",
> +	      __func__, priv->die_id, priv->die_rev);
> +
> +	return 0;
> +}
> +
> +static const struct dm_regulator_ops fan53555_regulator_ops = {
> +	.get_value	= fan53555_regulator_get_value,
> +	.set_value	= fan53555_regulator_set_value,
> +};
> +
> +static const struct udevice_id fan53555_regulator_ids[] = {
> +	{ .compatible = "fcs,fan53555" },
> +	{ },
> +};
> +
> +U_BOOT_DRIVER(fan53555_regulator) = {
> +	.name = "fan53555 regulator",
> +	.id = UCLASS_REGULATOR,
> +	.ops = &fan53555_regulator_ops,
> +	.of_match = fan53555_regulator_ids,
> +	.ofdata_to_platdata = fan53555_regulator_ofdata_to_platdata,
> +	.platdata_auto_alloc_size = sizeof(struct fan53555_platdata),
> +	.priv_auto_alloc_size = sizeof(struct fan53555_priv),
> +	.probe = fan53555_probe,
> +};

Reviewed-by: Lukasz Majewski <lukma at denx.de>

Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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