[PATCH v6 07/13] power: regulator: Add AB8500 AUX3 support

Add regulator support for LDO AUX3 on AB8500 and AB8505 PMICs.
AUX3 supplies the removable SD card on the upstream Ux500 Samsung
device trees.

Support the AB8505-specific 3.05 V selector override and clear it after
programming an ordinary voltage. Treat both normal and low-power modes
as enabled and select the supported voltage closest to a requested
target. AB8500 cut 2.0 or later is assumed.

Imply the regulator core for ARCH_U8500 so the driver can instantiate
from the upstream device trees.

Signed-off-by: Linus Walleij <[email protected]>
---
 MAINTAINERS                      |   1 +
 arch/arm/Kconfig                 |   2 +
 drivers/power/pmic/ab8500.c      |   1 +
 drivers/power/regulator/Kconfig  |   7 ++
 drivers/power/regulator/Makefile |   1 +
 drivers/power/regulator/ab8500.c | 171 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 183 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index a5d6b5be29dc..8e78a7f224fa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -790,6 +790,7 @@ F:	drivers/gpio/nmk_gpio.c
 F:	drivers/pinctrl/pinctrl-nomadik.c
 F:	drivers/phy/phy-ab8500-usb.c
 F:	drivers/power/pmic/ab8500.c
+F:	drivers/power/regulator/ab8500.c
 F:	drivers/timer/nomadik-mtu-timer.c
 F:	drivers/usb/musb-new/ux500.c
 F:	drivers/video/mcde_simple.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5b02ff18bd0e..62aa9e8cc565 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1275,6 +1275,7 @@ config ARCH_U8500
 	imply ARM_PL180_MMCI
 	imply CLK
 	imply DM_PMIC
+	imply DM_REGULATOR
 	imply DM_RTC
 	imply NOMADIK_GPIO
 	imply NOMADIK_MTU_TIMER
@@ -1283,6 +1284,7 @@ config ARCH_U8500
 	imply PHY
 	imply PL01X_SERIAL
 	imply PMIC_AB8500
+	imply REGULATOR_AB8500
 	imply RTC_PL031
 	imply SYS_THUMB_BUILD
 	imply SYSRESET_SYSCON
diff --git a/drivers/power/pmic/ab8500.c b/drivers/power/pmic/ab8500.c
index 9ba096711e14..b9fae7000b78 100644
--- a/drivers/power/pmic/ab8500.c
+++ b/drivers/power/pmic/ab8500.c
@@ -253,6 +253,7 @@ static int ab8500_probe(struct udevice *dev)
 
 static const struct udevice_id ab8500_ids[] = {
 	{ .compatible = "stericsson,ab8500" },
+	{ .compatible = "stericsson,ab8505" },
 	{ }
 };
 
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 00a25acfdf99..a27fe4925cf9 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -16,6 +16,13 @@ config DM_REGULATOR
 	  for this purpose if PMIC I/O driver is implemented or dm_scan_fdt_dev()
 	  otherwise. Detailed information can be found in the header file.
 
+config REGULATOR_AB8500
+	bool "ST-Ericsson AB8500/AB8505 regulator support"
+	depends on DM_REGULATOR && PMIC_AB8500
+	help
+	  Enable LDO AUX3 regulator support for AB8500 and AB8505 PMICs.
+	  This supply is used to power removable SD cards on Ux500 boards.
+
 config SPL_DM_REGULATOR
 	bool "Enable regulators for SPL"
 	depends on DM_REGULATOR && SPL_POWER
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index a40c9d340d98..a500a3da98d4 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -5,6 +5,7 @@
 #
 
 obj-$(CONFIG_$(PHASE_)DM_REGULATOR) += regulator-uclass.o
+obj-$(CONFIG_REGULATOR_AB8500) += ab8500.o
 obj-$(CONFIG_REGULATOR_ACT8846) += act8846.o
 obj-$(CONFIG_REGULATOR_AS3722)	+= as3722_regulator.o
 obj-$(CONFIG_$(PHASE_)REGULATOR_AXP) += axp_regulator.o
diff --git a/drivers/power/regulator/ab8500.c b/drivers/power/regulator/ab8500.c
new file mode 100644
index 000000000000..4cd15c5fcf86
--- /dev/null
+++ b/drivers/power/regulator/ab8500.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* ST-Ericsson AB8500/AB8505 LDO AUX3 regulator */
+
+#include <dm.h>
+#include <dm/lists.h>
+#include <linux/errno.h>
+#include <power/ab8500.h>
+#include <power/pmic.h>
+#include <power/regulator.h>
+
+#define AB8500_VAUX3_REGU		AB8500_REGU_CTRL2(0x0a)
+#define AB8500_VAUX3_REGU_EN_MASK	GENMASK(1, 0)
+#define AB8500_VAUX3_REGU_EN		BIT(0)
+
+#define AB8500_VAUX3_SEL	AB8500_REGU_CTRL2(0x21)
+#define AB8500_VAUX3_SEL_MASK	GENMASK(2, 0)
+
+#define AB8505_VAUX3_SEL3	AB8500_REGU_CTRL2(0x01)
+
+#define AB8505_VAUX3_SEL3_MASK	BIT(4)
+#define AB8505_VAUX3_SEL3_UV	3050000
+
+static const int ab8500_vaux3_voltages[] = {
+	1200000, 1500000, 1800000, 2100000,
+	2500000, 2750000, 2790000, 2910000,
+};
+
+static struct udevice *ab8500_regulator_pmic(struct udevice *dev)
+{
+	return dev->parent->parent;
+}
+
+static int ab8500_regulator_get_value(struct udevice *dev)
+{
+	struct udevice *pmic = ab8500_regulator_pmic(dev);
+	int ret;
+
+	if (device_is_compatible(pmic, "stericsson,ab8505")) {
+		ret = pmic_reg_read(pmic, AB8505_VAUX3_SEL3);
+		if (ret < 0)
+			return ret;
+		if (ret & AB8505_VAUX3_SEL3_MASK)
+			return AB8505_VAUX3_SEL3_UV;
+	}
+
+	ret = pmic_reg_read(pmic, AB8500_VAUX3_SEL);
+	if (ret < 0)
+		return ret;
+	ret &= AB8500_VAUX3_SEL_MASK;
+
+	return ab8500_vaux3_voltages[ret];
+}
+
+static int ab8500_regulator_set_value(struct udevice *dev, int uV)
+{
+	struct udevice *pmic = ab8500_regulator_pmic(dev);
+	bool is_ab8505 = device_is_compatible(pmic, "stericsson,ab8505");
+	int ret;
+	int i;
+
+	if (uV == AB8505_VAUX3_SEL3_UV) {
+		if (!is_ab8505)
+			return -EINVAL;
+
+		return pmic_clrsetbits(pmic, AB8505_VAUX3_SEL3,
+				       AB8505_VAUX3_SEL3_MASK,
+				       AB8505_VAUX3_SEL3_MASK);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_vaux3_voltages); i++) {
+		if (ab8500_vaux3_voltages[i] != uV)
+			continue;
+
+		ret = pmic_clrsetbits(pmic, AB8500_VAUX3_SEL,
+				      AB8500_VAUX3_SEL_MASK, i);
+		if (ret || !is_ab8505)
+			return ret;
+
+		return pmic_clrsetbits(pmic, AB8505_VAUX3_SEL3,
+				       AB8505_VAUX3_SEL3_MASK, 0);
+	}
+
+	return -EINVAL;
+}
+
+static int ab8500_regulator_set_value_clamp(struct udevice *dev, int min_uV,
+					    int target_uV, int max_uV)
+{
+	struct udevice *pmic = ab8500_regulator_pmic(dev);
+	int best_uV = -EINVAL;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ab8500_vaux3_voltages); i++) {
+		int uV = ab8500_vaux3_voltages[i];
+
+		if (uV < min_uV || uV > max_uV)
+			continue;
+		if (best_uV < 0 || abs(uV - target_uV) <
+				   abs(best_uV - target_uV))
+			best_uV = uV;
+	}
+
+	if (device_is_compatible(pmic, "stericsson,ab8505") &&
+	    min_uV <= AB8505_VAUX3_SEL3_UV &&
+	    max_uV >= AB8505_VAUX3_SEL3_UV &&
+	    (best_uV < 0 || abs(AB8505_VAUX3_SEL3_UV - target_uV) <
+	     abs(best_uV - target_uV)))
+		best_uV = AB8505_VAUX3_SEL3_UV;
+
+	if (best_uV < 0)
+		return best_uV;
+
+	return ab8500_regulator_set_value(dev, best_uV);
+}
+
+static int ab8500_regulator_get_enable(struct udevice *dev)
+{
+	int ret;
+
+	ret = pmic_reg_read(ab8500_regulator_pmic(dev), AB8500_VAUX3_REGU);
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & AB8500_VAUX3_REGU_EN_MASK);
+}
+
+static int ab8500_regulator_set_enable(struct udevice *dev, bool enable)
+{
+	return pmic_clrsetbits(ab8500_regulator_pmic(dev), AB8500_VAUX3_REGU,
+			       AB8500_VAUX3_REGU_EN_MASK,
+			       enable ? AB8500_VAUX3_REGU_EN : 0);
+}
+
+static const struct dm_regulator_ops ab8500_regulator_ops = {
+	.get_value = ab8500_regulator_get_value,
+	.set_value = ab8500_regulator_set_value,
+	.set_value_clamp = ab8500_regulator_set_value_clamp,
+	.get_enable = ab8500_regulator_get_enable,
+	.set_enable = ab8500_regulator_set_enable,
+};
+
+U_BOOT_DRIVER(ab8500_ldo_aux3) = {
+	.name = "ab8500_ldo_aux3",
+	.id = UCLASS_REGULATOR,
+	.ops = &ab8500_regulator_ops,
+};
+
+static int ab8500_regulators_bind(struct udevice *dev)
+{
+	ofnode node;
+
+	node = dev_read_subnode(dev, "ab8500_ldo_aux3");
+	if (!ofnode_valid(node))
+		return -ENODEV;
+
+	return device_bind_driver_to_node(dev, "ab8500_ldo_aux3",
+					  ofnode_get_name(node), node, NULL);
+}
+
+static const struct udevice_id ab8500_regulator_ids[] = {
+	{ .compatible = "stericsson,ab8500-regulator" },
+	{ .compatible = "stericsson,ab8505-regulator" },
+	{ }
+};
+
+U_BOOT_DRIVER(ab8500_regulators) = {
+	.name = "ab8500_regulators",
+	.id = UCLASS_NOP,
+	.of_match = ab8500_regulator_ids,
+	.bind = ab8500_regulators_bind,
+};

-- 
2.55.0