[U-Boot] [RESEND][PATCH v1 0/4] Add STM32 VREFBUF regulator driver

[U-Boot] [RESEND][PATCH v1 0/4] Add STM32 VREFBUF regulator driver

[Patrice Chotard]

This series :
  _ adds STM32 VREFBUF regulator driver
  _ adds VREFBUF clock gating
  _ enables STM32_VREFBUF flag in stm32mp15_basic_defconfig
  _ adds VREFBUF DT node


Fabrice Gasnier (3):
  power: regulator: Add support for stm32-vrefbuf
  clk: stm32mp1: Add VREF clock gating
  configs: stm32mp15: Enable STM32_VREFBUF flag

Patrice Chotard (1):
  ARM: dts: stm32mp157: Add vrefbuf DT node

 arch/arm/dts/stm32mp157.dtsi                       |   9 ++
 configs/stm32mp15_basic_defconfig                  |   1 +
 .../regulator/st,stm32-vrefbuf.txt                 |  23 +++
 drivers/clk/clk_stm32mp1.c                         |   3 +
 drivers/power/regulator/Kconfig                    |   9 ++
 drivers/power/regulator/Makefile                   |   1 +
 drivers/power/regulator/stm32-vrefbuf.c            | 156 +++++++++++++++++++++
 7 files changed, 202 insertions(+)
 create mode 100644 doc/device-tree-bindings/regulator/st,stm32-vrefbuf.txt
 create mode 100644 drivers/power/regulator/stm32-vrefbuf.c

-- 
1.9.1

[U-Boot] [RESEND][PATCH v1 1/4] power: regulator: Add support for stm32-vrefbuf

[Patrice Chotard]

From: Fabrice Gasnier <fabrice.gasnier@st.com>

Add regulator driver for STM32 voltage reference buffer which can be
used as voltage reference for ADCs, DACs and external components through
dedicated VREF+ pin.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---

 .../regulator/st,stm32-vrefbuf.txt                 |  23 +++
 drivers/power/regulator/Kconfig                    |   9 ++
 drivers/power/regulator/Makefile                   |   1 +
 drivers/power/regulator/stm32-vrefbuf.c            | 156 +++++++++++++++++++++
 4 files changed, 189 insertions(+)
 create mode 100644 doc/device-tree-bindings/regulator/st,stm32-vrefbuf.txt
 create mode 100644 drivers/power/regulator/stm32-vrefbuf.c

diff --git a/doc/device-tree-bindings/regulator/st,stm32-vrefbuf.txt b/doc/device-tree-bindings/regulator/st,stm32-vrefbuf.txt
new file mode 100644
index 000000000000..0f6b6feda33f
--- /dev/null
+++ b/doc/device-tree-bindings/regulator/st,stm32-vrefbuf.txt
@@ -0,0 +1,23 @@
+STM32 VREFBUF - Voltage reference buffer
+
+Some STM32 devices embed a voltage reference buffer which can be used as
+voltage reference for ADCs, DACs and also as voltage reference for external
+components through the dedicated VREF+ pin.
+
+Required properties:
+- compatible:		Must be "st,stm32-vrefbuf".
+- reg:			Offset and length of VREFBUF register set.
+- clocks:		Must contain an entry for peripheral clock.
+
+Optional properties:
+- vdda-supply:		Phandle to the parent vdda supply regulator node.
+
+Example:
+	vrefbuf: regulator at 58003c00 {
+		compatible = "st,stm32-vrefbuf";
+		reg = <0x58003C00 0x8>;
+		clocks = <&rcc VREF_CK>;
+		regulator-min-microvolt = <1500000>;
+		regulator-max-microvolt = <2500000>;
+		vdda-supply = <&vdda>;
+	};
diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
index 822cff6608b8..414f4a53f786 100644
--- a/drivers/power/regulator/Kconfig
+++ b/drivers/power/regulator/Kconfig
@@ -197,6 +197,15 @@ config DM_REGULATOR_LP87565
 	be configured in multi phase modes. The driver implements
 	get/set api for value and enable.
 
+config DM_REGULATOR_STM32_VREFBUF
+	bool "Enable driver for STMicroelectronics STM32 VREFBUF"
+	depends on DM_REGULATOR && (STM32H7 || ARCH_STM32MP)
+	help
+	This driver supports STMicroelectronics STM32 VREFBUF (voltage
+	reference buffer) which can be used as voltage reference for
+	internal ADCs, DACs and also for external components through
+	dedicated Vref+ pin.
+
 config DM_REGULATOR_TPS65910
 	bool "Enable driver for TPS65910 PMIC regulators"
 	depends on DM_PMIC_TPS65910
diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
index d73a6e3577a9..16208af0694b 100644
--- a/drivers/power/regulator/Makefile
+++ b/drivers/power/regulator/Makefile
@@ -22,5 +22,6 @@ obj-$(CONFIG_$(SPL_)DM_REGULATOR_PALMAS) += palmas_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_PBIAS) += pbias_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_LP873X) += lp873x_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_LP87565) += lp87565_regulator.o
+obj-$(CONFIG_$(SPL_)DM_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
 obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o
 obj-$(CONFIG_$(SPL_)DM_REGULATOR_STPMU1) += stpmu1.o
diff --git a/drivers/power/regulator/stm32-vrefbuf.c b/drivers/power/regulator/stm32-vrefbuf.c
new file mode 100644
index 000000000000..eeb055cc6321
--- /dev/null
+++ b/drivers/power/regulator/stm32-vrefbuf.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
+ *
+ * Originally based on the Linux kernel v4.16 drivers/regulator/stm32-vrefbuf.c
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <power/regulator.h>
+
+/* STM32 VREFBUF registers */
+#define STM32_VREFBUF_CSR		0x00
+
+/* STM32 VREFBUF CSR bitfields */
+#define STM32_VRS			GENMASK(6, 4)
+#define STM32_VRS_SHIFT			4
+#define STM32_VRR			BIT(3)
+#define STM32_HIZ			BIT(1)
+#define STM32_ENVR			BIT(0)
+
+struct stm32_vrefbuf {
+	void __iomem *base;
+	struct clk clk;
+	struct udevice *vdda_supply;
+};
+
+static const unsigned int stm32_vrefbuf_voltages[] = {
+	/* Matches resp. VRS = 000b, 001b, 010b, 011b */
+	2500000, 2048000, 1800000, 1500000,
+};
+
+static int stm32_vrefbuf_set_enable(struct udevice *dev, bool enable)
+{
+	struct stm32_vrefbuf *priv = dev_get_priv(dev);
+	u32 val;
+	int ret;
+
+	clrsetbits_le32(priv->base + STM32_VREFBUF_CSR, STM32_HIZ | STM32_ENVR,
+			enable ? STM32_ENVR : STM32_HIZ);
+	if (!enable)
+		return 0;
+
+	/*
+	 * Vrefbuf startup time depends on external capacitor: wait here for
+	 * VRR to be set. That means output has reached expected value.
+	 * ~650us sleep should be enough for caps up to 1.5uF. Use 10ms as
+	 * arbitrary timeout.
+	 */
+	ret = readl_poll_timeout(priv->base + STM32_VREFBUF_CSR, val,
+				 val & STM32_VRR, 10000);
+	if (ret < 0) {
+		dev_err(dev, "stm32 vrefbuf timed out: %d\n", ret);
+		clrsetbits_le32(priv->base + STM32_VREFBUF_CSR, STM32_ENVR,
+				STM32_HIZ);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_vrefbuf_get_enable(struct udevice *dev)
+{
+	struct stm32_vrefbuf *priv = dev_get_priv(dev);
+
+	return readl(priv->base + STM32_VREFBUF_CSR) & STM32_ENVR;
+}
+
+static int stm32_vrefbuf_set_value(struct udevice *dev, int uV)
+{
+	struct stm32_vrefbuf *priv = dev_get_priv(dev);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(stm32_vrefbuf_voltages); i++) {
+		if (uV == stm32_vrefbuf_voltages[i]) {
+			clrsetbits_le32(priv->base + STM32_VREFBUF_CSR,
+					STM32_VRS, i << STM32_VRS_SHIFT);
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int stm32_vrefbuf_get_value(struct udevice *dev)
+{
+	struct stm32_vrefbuf *priv = dev_get_priv(dev);
+	u32 val;
+
+	val = readl(priv->base + STM32_VREFBUF_CSR) & STM32_VRS;
+	val >>= STM32_VRS_SHIFT;
+
+	return stm32_vrefbuf_voltages[val];
+}
+
+static const struct dm_regulator_ops stm32_vrefbuf_ops = {
+	.get_value  = stm32_vrefbuf_get_value,
+	.set_value  = stm32_vrefbuf_set_value,
+	.get_enable = stm32_vrefbuf_get_enable,
+	.set_enable = stm32_vrefbuf_set_enable,
+};
+
+static int stm32_vrefbuf_probe(struct udevice *dev)
+{
+	struct stm32_vrefbuf *priv = dev_get_priv(dev);
+	int ret;
+
+	priv->base = dev_read_addr_ptr(dev);
+
+	ret = clk_get_by_index(dev, 0, &priv->clk);
+	if (ret) {
+		dev_err(dev, "Can't get clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_enable(&priv->clk);
+	if (ret) {
+		dev_err(dev, "Can't enable clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = device_get_supply_regulator(dev, "vdda-supply",
+					  &priv->vdda_supply);
+	if (ret) {
+		dev_dbg(dev, "No vdda-supply: %d\n", ret);
+		return 0;
+	}
+
+	ret = regulator_set_enable(priv->vdda_supply, true);
+	if (ret) {
+		dev_err(dev, "Can't enable vdda-supply: %d\n", ret);
+		clk_disable(&priv->clk);
+	}
+
+	return ret;
+}
+
+static const struct udevice_id stm32_vrefbuf_ids[] = {
+	{ .compatible = "st,stm32-vrefbuf" },
+	{ }
+};
+
+U_BOOT_DRIVER(stm32_vrefbuf) = {
+	.name  = "stm32-vrefbuf",
+	.id = UCLASS_REGULATOR,
+	.of_match = stm32_vrefbuf_ids,
+	.probe = stm32_vrefbuf_probe,
+	.ops = &stm32_vrefbuf_ops,
+	.priv_auto_alloc_size = sizeof(struct stm32_vrefbuf),
+};
-- 
1.9.1

[U-Boot] [RESEND][PATCH v1 2/4] clk: stm32mp1: Add VREF clock gating

[Patrice Chotard]

From: Fabrice Gasnier <fabrice.gasnier@st.com>

Add VREF clock gating, that may be used by STM32 VREFBUF regulator.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---

 drivers/clk/clk_stm32mp1.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/clk/clk_stm32mp1.c b/drivers/clk/clk_stm32mp1.c
index c67aa444735a..97e9c12dd248 100644
--- a/drivers/clk/clk_stm32mp1.c
+++ b/drivers/clk/clk_stm32mp1.c
@@ -101,6 +101,7 @@
 #define RCC_USBCKSELR		0x91C
 #define RCC_MP_APB1ENSETR	0xA00
 #define RCC_MP_APB2ENSETR	0XA08
+#define RCC_MP_APB3ENSETR	0xA10
 #define RCC_MP_AHB2ENSETR	0xA18
 #define RCC_MP_AHB4ENSETR	0xA28
 
@@ -509,6 +510,8 @@ static const struct stm32mp1_clk_gate stm32mp1_clk_gate[] = {
 
 	STM32MP1_CLK_SET_CLR(RCC_MP_APB2ENSETR, 13, USART6_K, _UART6_SEL),
 
+	STM32MP1_CLK_SET_CLR_F(RCC_MP_APB3ENSETR, 13, VREF, _PCLK3),
+
 	STM32MP1_CLK_SET_CLR(RCC_MP_APB4ENSETR, 8, DDRPERFM, _UNKNOWN_SEL),
 	STM32MP1_CLK_SET_CLR(RCC_MP_APB4ENSETR, 15, IWDG2, _UNKNOWN_SEL),
 	STM32MP1_CLK_SET_CLR(RCC_MP_APB4ENSETR, 16, USBPHY_K, _USBPHY_SEL),
-- 
1.9.1

[U-Boot] [RESEND][PATCH v1 3/4] configs: stm32mp15: Enable STM32_VREFBUF flag

[Patrice Chotard]

From: Fabrice Gasnier <fabrice.gasnier@st.com>

Enable vrefbuf on stm32mp15, to be used by ADC.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---

 configs/stm32mp15_basic_defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index 195efa1ce06d..b1c3690c0094 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -36,6 +36,7 @@ CONFIG_DM_PMIC=y
 CONFIG_PMIC_STPMU1=y
 CONFIG_DM_REGULATOR=y
 CONFIG_DM_REGULATOR_GPIO=y
+CONFIG_DM_REGULATOR_STM32_VREFBUF=y
 CONFIG_DM_REGULATOR_STPMU1=y
 CONFIG_STM32_SERIAL=y
 # CONFIG_EFI_LOADER is not set
-- 
1.9.1

[U-Boot] [RESEND][PATCH v1 4/4] ARM: dts: stm32mp157: Add vrefbuf DT node

[Patrice Chotard]

Add vrefbuf device tree node. This allows to get
a voltage reference for ADCs.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
---

 arch/arm/dts/stm32mp157.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/dts/stm32mp157.dtsi b/arch/arm/dts/stm32mp157.dtsi
index b84899a1ea94..4b65d41f38cb 100644
--- a/arch/arm/dts/stm32mp157.dtsi
+++ b/arch/arm/dts/stm32mp157.dtsi
@@ -123,6 +123,15 @@
 			};
 		};
 
+		vrefbuf: vrefbuf at 50025000 {
+			compatible = "st,stm32-vrefbuf";
+			reg = <0x50025000 0x8>;
+			regulator-min-microvolt = <1500000>;
+			regulator-max-microvolt = <2500000>;
+			clocks = <&rcc_clk VREF>;
+			status = "disabled";
+		};
+
 		pinctrl: pin-controller {
 			compatible = "st,stm32mp157-pinctrl";
 			#address-cells = <1>;
-- 
1.9.1

[U-Boot] [U-Boot, RESEND, v1, 1/4] power: regulator: Add support for stm32-vrefbuf

[Tom Rini]

On Thu, Apr 26, 2018 at 05:00:46PM +0200, Patrice Chotard wrote:

> From: Fabrice Gasnier <fabrice.gasnier@st.com>
> 
> Add regulator driver for STM32 voltage reference buffer which can be
> used as voltage reference for ADCs, DACs and external components through
> dedicated VREF+ pin.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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[U-Boot] [U-Boot, RESEND, v1, 2/4] clk: stm32mp1: Add VREF clock gating

[Tom Rini]

On Thu, Apr 26, 2018 at 05:00:47PM +0200, Patrice Chotard wrote:

> From: Fabrice Gasnier <fabrice.gasnier@st.com>
> 
> Add VREF clock gating, that may be used by STM32 VREFBUF regulator.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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[U-Boot] [U-Boot, RESEND, v1, 3/4] configs: stm32mp15: Enable STM32_VREFBUF flag

[Tom Rini]

On Thu, Apr 26, 2018 at 05:00:48PM +0200, Patrice Chotard wrote:

> From: Fabrice Gasnier <fabrice.gasnier@st.com>
> 
> Enable vrefbuf on stm32mp15, to be used by ADC.
> 
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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[U-Boot] [U-Boot, RESEND, v1, 4/4] ARM: dts: stm32mp157: Add vrefbuf DT node

[Tom Rini]

On Thu, Apr 26, 2018 at 05:00:49PM +0200, Patrice Chotard wrote:

> Add vrefbuf device tree node. This allows to get
> a voltage reference for ADCs.
> 
> Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

Applied to u-boot/master, thanks!

-- 
Tom
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