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

* [U-Boot] [PATCH v2 1/2] power: regulator: add driver for the FAN53555 family
@ 2017-11-22 21:13 Philipp Tomsich
  2017-11-22 21:13 ` [U-Boot] [PATCH v2 2/2] rockchip: defconfig: puma-rk3399: enable FAN53555 regulator driver Philipp Tomsich
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Philipp Tomsich @ 2017-11-22 21:13 UTC (permalink / raw)
  To: u-boot

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@theobroma-systems.com>
Tested-by: Klaus Goger <klaus.goger@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,
+};
-- 
2.1.4

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