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

Simon Glass sjg at chromium.org
Sun Nov 26 11:38:56 UTC 2017


Hi Philipp,

On 22 November 2017 at 14:13, Philipp Tomsich
<philipp.tomsich at theobroma-systems.com> wrote:
> 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

Reviewed-by: Simon Glass <sjg at chromium.org>

Nits below.

>
> 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.
> + */

struct comment?

> +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)

In this file en is only ever 1. How about using pmic_reg_write()?

> +{
> +       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)

pmic_reg_read()?

> +{
> +       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 cannot happen so this check is unnecessary, and I think it is
confusing too.

> +
> +       /* 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);

error check

> +       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);

more error checks here and below

> +       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;

Again, please drop this check

> +
> +       /* 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,
> +};
> --
> 2.1.4
>

Regards,
Simon


More information about the U-Boot mailing list