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Add DAC driver support for Vybrid SoC

PATCH Superseded Sanchayan Maity 2 participants 5 messages Feb 15, 2016 – Feb 21, 2016

Subsystems (2)
Device tree bindings IIO

v2 of 3 Superseded Latest is v3 →

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Sanchayan Maity

author
#0 lore raw

v2 cover Add DAC driver support for Vybrid SoC

Hello,

This patchset adds support for the DAC peripheral on Vybrid SoC. Patchset is based on top of shawn's for-next branch and has been tested on a Toradex Colibri VF50 module.

@Jonathan
I kept the IIO_SHARED_BY_DIR instead of using IIO_SHARED_BY_ALL since this gives "out_conversion_mode" allowing me to distinguish this in the ABI documentation, that this is explicitly for the DAC.

Since 4.5-rc4 was released recently and assuming this makes it with this or next version, I assumed the target kernel version would be 4.6 and used that in ABI documentation.

Feedbacks and comments most welcome.

Changes since v1:
1. Fix return type of vf610_dac_init function
2. Document conversion modes in sysfs-bus-iio-vf610
3. Remove "indexed" specification from iio_chan_spec
4. Use "return" directly from default case in switch
5. Remove DRIVER_NAME
6. Call vf610_dac_init before iio device registration
7. Define and use vf610_dac_exit function in remove and suspend
8. Add sysfs ABI documentation

v1 of the patchset:
http://www.spinics.net/lists/arm-kernel/msg481190.html

Thanks & Regards,
Sanchayan Maity.

Sanchayan Maity (2):
ARM: dts: vfxxx: Add DAC node for Vybrid SoC
iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC

 Documentation/ABI/testing/sysfs-bus-iio-vf610      |   9 +
 .../devicetree/bindings/iio/dac/vf610-dac.txt      |  20 ++
 arch/arm/boot/dts/vfxxx.dtsi                       |  18 ++
 drivers/iio/dac/Kconfig                            |   8 +
 drivers/iio/dac/Makefile                           |   1 +
 drivers/iio/dac/vf610_dac.c                        | 298 +++++++++++++++++++++
 6 files changed, 354 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
 create mode 100644 drivers/iio/dac/vf610_dac.c
Signature · 1 line
2.7.1
author
#1 lore raw

PATCH v2 1/2 ARM: dts: vfxxx: Add DAC node for Vybrid SoC

Add a device tree node entry for DAC peripheral on Vybrid SoC.

Signed-off-by Sanchayan Maity <[email protected]>
---
 arch/arm/boot/dts/vfxxx.dtsi | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
arch/arm/boot/dts/vfxxx.dtsi +18 -0
index a5f07e3..8238069 100644
@@ -602,6 +602,24 @@
 				status = "disabled";
 			};
 
+			dac0: dac at 400cc000 {
+				compatible = "fsl,vf610-dac";
+				reg = <0x400cc000 1000>;
+				interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
+				clock-names = "dac";
+				clocks = <&clks VF610_CLK_DAC0>;
+				status = "disabled";
+			};
+
+			dac1: dac at 400cd000 {
+				compatible = "fsl,vf610-dac";
+				reg = <0x400cd000 1000>;
+				interrupts = <56 IRQ_TYPE_LEVEL_HIGH>;
+				clock-names = "dac";
+				clocks = <&clks VF610_CLK_DAC1>;
+				status = "disabled";
+			};
+
 			fec0: ethernet at 400d0000 {
 				compatible = "fsl,mvf600-fec";
 				reg = <0x400d0000 0x1000>;
Signature · 1 line
2.7.1
author
#2 lore raw

PATCH v2 2/2 iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC

In reply to Sanchayan Maity

Add driver support for DAC peripheral on Vybrid SoC.

Signed-off-by Sanchayan Maity <[email protected]>
Acked-by Rob Herring <[email protected]>
---
 Documentation/ABI/testing/sysfs-bus-iio-vf610      |   9 +
 .../devicetree/bindings/iio/dac/vf610-dac.txt      |  20 ++
 drivers/iio/dac/Kconfig                            |   8 +
 drivers/iio/dac/Makefile                           |   1 +
 drivers/iio/dac/vf610_dac.c                        | 298 +++++++++++++++++++++
 5 files changed, 336 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
 create mode 100644 drivers/iio/dac/vf610_dac.c
Documentation/ABI/testing/sysfs-bus-iio-vf610 +9 -0
index ecbc1f4..5ea809c 100644
@@ -5,3 +5,12 @@ Description:
 		Specifies the hardware conversion mode used. The three
 		available modes are "normal", "high-speed" and "low-power",
 		where the last is the default mode.
+
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_conversion_mode
+KernelVersion:	4.6
+Contact:	linux-iio at vger.kernel.org
+Description:
+		Specifies the hardware conversion mode used within DAC.
+		The two available modes are "high-power" and "low-power",
+		where "low-power" mode is the default mode.
\ No newline at end of file
Documentation/devicetree/bindings/iio/dac/vf610-dac.txt new file +20 -0
new file mode 100644
index 0000000..20c6c7a
@@ -0,0 +1,20 @@
+Freescale vf610 Digital to Analog Converter bindings
+
+The devicetree bindings are for the new DAC driver written for
+vf610 SoCs from Freescale.
+
+Required properties:
+- compatible: Should contain "fsl,vf610-dac"
+- reg: Offset and length of the register set for the device
+- interrupts: Should contain the interrupt for the device
+- clocks: The clock is needed by the DAC controller
+- clock-names: Must contain "dac" matching entry in the clocks property.
+
+Example:
+dac0: dac at 400cc000 {
+	compatible = "fsl,vf610-dac";
+	reg = <0x400cc000 0x1000>;
+	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
+	clock-names = "dac";
+	clocks = <&clks VF610_CLK_DAC0>;
+};
drivers/iio/dac/Kconfig +8 -0
index e701e28..8eb0502 100644
@@ -196,4 +196,12 @@ config MCP4922
 	  To compile this driver as a module, choose M here: the module
 	  will be called mcp4922.
 
+config VF610_DAC
+	tristate "Vybrid vf610 DAC driver"
+	help
+	  Say yes here to support Vybrid board digital-to-analog converter.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called vf610_dac.
+
 endmenu
drivers/iio/dac/Makefile +1 -0
index 63ae056..93feb27 100644
@@ -21,3 +21,4 @@ obj-$(CONFIG_MAX517) += max517.o
 obj-$(CONFIG_MAX5821) += max5821.o
 obj-$(CONFIG_MCP4725) += mcp4725.o
 obj-$(CONFIG_MCP4922) += mcp4922.o
+obj-$(CONFIG_VF610_DAC) += vf610_dac.o
drivers/iio/dac/vf610_dac.c new file +298 -0

298 lines not on this page · raw message

Signature · 1 line
2.7.1
maintainer
#3 lore raw

PATCH v2 2/2 iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC

Quoted 4 lines · Sanchayan Maity

Add driver support for DAC peripheral on Vybrid SoC.

Signed-off-by Sanchayan Maity <[email protected]>
Acked-by Rob Herring <[email protected]>

Ordering is wrong in remove. I may well fix this up and apply later today.
Otherwise looks good to me.

Quoted 332 lines

---

Documentation/ABI/testing/sysfs-bus-iio-vf610      |   9 +
.../devicetree/bindings/iio/dac/vf610-dac.txt      |  20 ++
drivers/iio/dac/Kconfig                            |   8 +
drivers/iio/dac/Makefile                           |   1 +
drivers/iio/dac/vf610_dac.c                        | 298
+++++++++++++++++++++
5 files changed, 336 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/dac/vf610-dac.txt create mode 100644 drivers/iio/dac/vf610_dac.c

Documentation/ABI/testing/sysfs-bus-iio-vf610 +9 -0
index ecbc1f4..5ea809c 100644
@@ -5,3 +5,12 @@ Description:
 		Specifies the hardware conversion mode used. The three
 		available modes are "normal", "high-speed" and "low-power",
 		where the last is the default mode.
+
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_conversion_mode
+KernelVersion:	4.6
+Contact:	linux-iio at vger.kernel.org
+Description:
+		Specifies the hardware conversion mode used within DAC.
+		The two available modes are "high-power" and "low-power",
+		where "low-power" mode is the default mode.
\ No newline at end of file
Documentation/devicetree/bindings/iio/dac/vf610-dac.txt new file +11 -0
new file mode 100644
index 0000000..20c6c7a
@@ -0,0 +1,20 @@
+Freescale vf610 Digital to Analog Converter bindings
+
+The devicetree bindings are for the new DAC driver written for
+vf610 SoCs from Freescale.
+
+Required properties:
+- compatible: Should contain "fsl,vf610-dac"
+- reg: Offset and length of the register set for the device
+- interrupts: Should contain the interrupt for the device
+- clocks: The clock is needed by the DAC controller
+- clock-names: Must contain "dac" matching entry in the clocks

property.

Documentation/devicetree/bindings/iio/dac/vf610-dac.txt new file +9 -0
+
+Example:
+dac0: dac at 400cc000 {
+	compatible = "fsl,vf610-dac";
+	reg = <0x400cc000 0x1000>;
+	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
+	clock-names = "dac";
+	clocks = <&clks VF610_CLK_DAC0>;
+};
drivers/iio/dac/Kconfig +8 -0
index e701e28..8eb0502 100644
@@ -196,4 +196,12 @@ config MCP4922
 	  To compile this driver as a module, choose M here: the module
 	  will be called mcp4922.
 
+config VF610_DAC
+	tristate "Vybrid vf610 DAC driver"
+	help
+	  Say yes here to support Vybrid board digital-to-analog converter.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called vf610_dac.
+

endmenu

drivers/iio/dac/Makefile +0 -0
index 63ae056..93feb27 100644
@@ -21,3 +21,4 @@ obj-$(CONFIG_MAX517) += max517.o

obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
obj-$(CONFIG_MCP4922) += mcp4922.o

drivers/iio/dac/Makefile +1 -0
+obj-$(CONFIG_VF610_DAC) += vf610_dac.o
drivers/iio/dac/vf610_dac.c new file +6 -0
new file mode 100644
index 0000000..3f70f96
@@ -0,0 +1,298 @@
+/*
+ * Freescale Vybrid vf610 DAC driver
+ *
+ * Copyright 2016 Toradex AG
+ *
+ * This program is free software; you can redistribute it and/or

modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */

drivers/iio/dac/vf610_dac.c new file +82 -0
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VF610_DACx_STATCTRL		0x20
+
+#define VF610_DAC_DACEN			BIT(15)
+#define VF610_DAC_DACRFS		BIT(14)
+#define VF610_DAC_LPEN			BIT(11)
+
+#define VF610_DAC_DAT0(x)		((x) & 0xFFF)
+
+enum vf610_conversion_mode_sel {
+	VF610_DAC_CONV_HIGH_POWER,
+	VF610_DAC_CONV_LOW_POWER,
+};
+
+struct vf610_dac {
+	struct clk *clk;
+	struct device *dev;
+	enum vf610_conversion_mode_sel conv_mode;
+	void __iomem *regs;
+};
+
+static void vf610_dac_init(struct vf610_dac *info)
+{
+	int val;
+
+	info->conv_mode = VF610_DAC_CONV_LOW_POWER;
+	val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
+		VF610_DAC_LPEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+}
+
+static void vf610_dac_exit(struct vf610_dac *info)
+{
+	int val;
+
+	val = readl(info->regs + VF610_DACx_STATCTRL);
+	val &= ~VF610_DAC_DACEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+}
+
+static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				unsigned int mode)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+	int val;
+
+	mutex_lock(&indio_dev->mlock);
+	info->conv_mode = mode;
+	val = readl(info->regs + VF610_DACx_STATCTRL);
+	if (mode)
+		val |= VF610_DAC_LPEN;
+	else
+		val &= ~VF610_DAC_LPEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+	mutex_unlock(&indio_dev->mlock);
+
+	return 0;
+}
+
+static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	return info->conv_mode;
+}
+
+static const char * const vf610_conv_modes[] = { "high-power",

"low-power" };

drivers/iio/dac/vf610_dac.c new file +141 -0
+
+static const struct iio_enum vf610_conversion_mode = {
+	.items = vf610_conv_modes,
+	.num_items = ARRAY_SIZE(vf610_conv_modes),
+	.get = vf610_get_conversion_mode,
+	.set = vf610_set_conversion_mode,
+};
+
+static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
+	IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
+		&vf610_conversion_mode),
+	{},
+};
+
+#define VF610_DAC_CHAN(_chan_type) { \
+	.type = (_chan_type), \
+	.output = 1, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.ext_info = vf610_ext_info, \
+}
+
+static const struct iio_chan_spec vf610_dac_iio_channels[] = {
+	VF610_DAC_CHAN(IIO_VOLTAGE),
+};
+
+static int vf610_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int *val, int *val2,
+			long mask)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*val = VF610_DAC_DAT0(readl(info->regs));
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * DACRFS is always 1 for valid reference and typical
+		 * reference voltage as per Vybrid datasheet is 3.3V
+		 * from section 9.1.2.1 of Vybrid datasheet
+		 */
+		*val = 3300 /* mV */;
+		*val2 = 12;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int vf610_write_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int val, int val2,
+			long mask)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		writel(VF610_DAC_DAT0(val), info->regs);
+		mutex_unlock(&indio_dev->mlock);
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info vf610_dac_iio_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &vf610_read_raw,
+	.write_raw = &vf610_write_raw,
+};
+
+static const struct of_device_id vf610_dac_match[] = {
+	{ .compatible = "fsl,vf610-dac", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vf610_dac_match);
+
+static int vf610_dac_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct vf610_dac *info;
+	struct resource *mem;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					sizeof(struct vf610_dac));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "Failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	info = iio_priv(indio_dev);
+	info->dev = &pdev->dev;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	info->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(info->regs))
+		return PTR_ERR(info->regs);
+
+	info->clk = devm_clk_get(&pdev->dev, "dac");
+	if (IS_ERR(info->clk)) {
+		dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
+			PTR_ERR(info->clk));
+		return PTR_ERR(info->clk);
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->info = &vf610_dac_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = vf610_dac_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Could not prepare or enable the clock\n");
+		return ret;
+	}
+
+	vf610_dac_init(info);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't register the device\n");
+		goto error_iio_device_register;
+	}
+
+	return 0;
+
+error_iio_device_register:
+	clk_disable_unprepare(info->clk);

drivers/iio/dac/vf610_dac.c line 248

Quoted 10 lines
drivers/iio/dac/vf610_dac.c new file +10 -0
+
+	return ret;
+}
+
+static int vf610_dac_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	vf610_dac_exit(info);

Should be reverse order of probe so exit after the unregister below. Right now you are disabling the hardware before removing the userspace interfaces.

Quoted 51 lines
drivers/iio/dac/vf610_dac.c new file +35 -0
+	iio_device_unregister(indio_dev);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int vf610_dac_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	vf610_dac_exit(info);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+static int vf610_dac_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+	int ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+
+	vf610_dac_init(info);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend,

vf610_dac_resume);

drivers/iio/dac/vf610_dac.c new file +15 -0
+
+static struct platform_driver vf610_dac_driver = {
+	.probe          = vf610_dac_probe,
+	.remove         = vf610_dac_remove,
+	.driver         = {
+		.name   = "vf610-dac",
+		.of_match_table = vf610_dac_match,
+		.pm     = &vf610_dac_pm_ops,
+	},
+};
+module_platform_driver(vf610_dac_driver);
+
+MODULE_AUTHOR("Sanchayan Maity <[email protected]");
+MODULE_DESCRIPTION("Freescale VF610 DAC driver");
+MODULE_LICENSE("GPL v2");
Signature · 1 line
Sent from my Android device with K-9 Mail. Please excuse my brevity.
maintainer
#4 lore raw

PATCH v2 2/2 iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC

Quoted 8 lines · Jonathan Cameron
Quoted 4 lines · Sanchayan Maity

Add driver support for DAC peripheral on Vybrid SoC.

Signed-off-by Sanchayan Maity <[email protected]>
Acked-by Rob Herring <[email protected]>

Ordering is wrong in remove. I may well fix this up and apply later today.

I also note that the Kconfig dependencies are rather sparse. Presumably needs depends on HAS_IOMEM at the very least. Anyhow, changes are getting less trivial so I'm not going to apply this without another revision.

Jonathan

Quoted 397 lines

Otherwise looks good to me.

Quoted 332 lines

---

Documentation/ABI/testing/sysfs-bus-iio-vf610      |   9 +
.../devicetree/bindings/iio/dac/vf610-dac.txt      |  20 ++
drivers/iio/dac/Kconfig                            |   8 +
drivers/iio/dac/Makefile                           |   1 +
drivers/iio/dac/vf610_dac.c                        | 298
+++++++++++++++++++++
5 files changed, 336 insertions(+)

create mode 100644 Documentation/devicetree/bindings/iio/dac/vf610-dac.txt create mode 100644 drivers/iio/dac/vf610_dac.c

Documentation/ABI/testing/sysfs-bus-iio-vf610 +9 -0
index ecbc1f4..5ea809c 100644
@@ -5,3 +5,12 @@ Description:
 		Specifies the hardware conversion mode used. The three
 		available modes are "normal", "high-speed" and "low-power",
 		where the last is the default mode.
+
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_conversion_mode
+KernelVersion:	4.6
+Contact:	linux-iio at vger.kernel.org
+Description:
+		Specifies the hardware conversion mode used within DAC.
+		The two available modes are "high-power" and "low-power",
+		where "low-power" mode is the default mode.
\ No newline at end of file
Documentation/devicetree/bindings/iio/dac/vf610-dac.txt new file +11 -0
new file mode 100644
index 0000000..20c6c7a
@@ -0,0 +1,20 @@
+Freescale vf610 Digital to Analog Converter bindings
+
+The devicetree bindings are for the new DAC driver written for
+vf610 SoCs from Freescale.
+
+Required properties:
+- compatible: Should contain "fsl,vf610-dac"
+- reg: Offset and length of the register set for the device
+- interrupts: Should contain the interrupt for the device
+- clocks: The clock is needed by the DAC controller
+- clock-names: Must contain "dac" matching entry in the clocks

property.

Documentation/devicetree/bindings/iio/dac/vf610-dac.txt new file +9 -0
+
+Example:
+dac0: dac at 400cc000 {
+	compatible = "fsl,vf610-dac";
+	reg = <0x400cc000 0x1000>;
+	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
+	clock-names = "dac";
+	clocks = <&clks VF610_CLK_DAC0>;
+};
drivers/iio/dac/Kconfig +8 -0
index e701e28..8eb0502 100644
@@ -196,4 +196,12 @@ config MCP4922
 	  To compile this driver as a module, choose M here: the module
 	  will be called mcp4922.
 
+config VF610_DAC
+	tristate "Vybrid vf610 DAC driver"
+	help
+	  Say yes here to support Vybrid board digital-to-analog converter.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called vf610_dac.
+

endmenu

drivers/iio/dac/Makefile +0 -0
index 63ae056..93feb27 100644
@@ -21,3 +21,4 @@ obj-$(CONFIG_MAX517) += max517.o

obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
obj-$(CONFIG_MCP4922) += mcp4922.o

drivers/iio/dac/Makefile +1 -0
+obj-$(CONFIG_VF610_DAC) += vf610_dac.o
drivers/iio/dac/vf610_dac.c new file +6 -0
new file mode 100644
index 0000000..3f70f96
@@ -0,0 +1,298 @@
+/*
+ * Freescale Vybrid vf610 DAC driver
+ *
+ * Copyright 2016 Toradex AG
+ *
+ * This program is free software; you can redistribute it and/or

modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */

drivers/iio/dac/vf610_dac.c new file +82 -0
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define VF610_DACx_STATCTRL		0x20
+
+#define VF610_DAC_DACEN			BIT(15)
+#define VF610_DAC_DACRFS		BIT(14)
+#define VF610_DAC_LPEN			BIT(11)
+
+#define VF610_DAC_DAT0(x)		((x) & 0xFFF)
+
+enum vf610_conversion_mode_sel {
+	VF610_DAC_CONV_HIGH_POWER,
+	VF610_DAC_CONV_LOW_POWER,
+};
+
+struct vf610_dac {
+	struct clk *clk;
+	struct device *dev;
+	enum vf610_conversion_mode_sel conv_mode;
+	void __iomem *regs;
+};
+
+static void vf610_dac_init(struct vf610_dac *info)
+{
+	int val;
+
+	info->conv_mode = VF610_DAC_CONV_LOW_POWER;
+	val = VF610_DAC_DACEN | VF610_DAC_DACRFS |
+		VF610_DAC_LPEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+}
+
+static void vf610_dac_exit(struct vf610_dac *info)
+{
+	int val;
+
+	val = readl(info->regs + VF610_DACx_STATCTRL);
+	val &= ~VF610_DAC_DACEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+}
+
+static int vf610_set_conversion_mode(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				unsigned int mode)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+	int val;
+
+	mutex_lock(&indio_dev->mlock);
+	info->conv_mode = mode;
+	val = readl(info->regs + VF610_DACx_STATCTRL);
+	if (mode)
+		val |= VF610_DAC_LPEN;
+	else
+		val &= ~VF610_DAC_LPEN;
+	writel(val, info->regs + VF610_DACx_STATCTRL);
+	mutex_unlock(&indio_dev->mlock);
+
+	return 0;
+}
+
+static int vf610_get_conversion_mode(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	return info->conv_mode;
+}
+
+static const char * const vf610_conv_modes[] = { "high-power",

"low-power" };

drivers/iio/dac/vf610_dac.c new file +141 -0
+
+static const struct iio_enum vf610_conversion_mode = {
+	.items = vf610_conv_modes,
+	.num_items = ARRAY_SIZE(vf610_conv_modes),
+	.get = vf610_get_conversion_mode,
+	.set = vf610_set_conversion_mode,
+};
+
+static const struct iio_chan_spec_ext_info vf610_ext_info[] = {
+	IIO_ENUM("conversion_mode", IIO_SHARED_BY_DIR,
+		&vf610_conversion_mode),
+	{},
+};
+
+#define VF610_DAC_CHAN(_chan_type) { \
+	.type = (_chan_type), \
+	.output = 1, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.ext_info = vf610_ext_info, \
+}
+
+static const struct iio_chan_spec vf610_dac_iio_channels[] = {
+	VF610_DAC_CHAN(IIO_VOLTAGE),
+};
+
+static int vf610_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int *val, int *val2,
+			long mask)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*val = VF610_DAC_DAT0(readl(info->regs));
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * DACRFS is always 1 for valid reference and typical
+		 * reference voltage as per Vybrid datasheet is 3.3V
+		 * from section 9.1.2.1 of Vybrid datasheet
+		 */
+		*val = 3300 /* mV */;
+		*val2 = 12;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int vf610_write_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int val, int val2,
+			long mask)
+{
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		writel(VF610_DAC_DAT0(val), info->regs);
+		mutex_unlock(&indio_dev->mlock);
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info vf610_dac_iio_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &vf610_read_raw,
+	.write_raw = &vf610_write_raw,
+};
+
+static const struct of_device_id vf610_dac_match[] = {
+	{ .compatible = "fsl,vf610-dac", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, vf610_dac_match);
+
+static int vf610_dac_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct vf610_dac *info;
+	struct resource *mem;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev,
+					sizeof(struct vf610_dac));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "Failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	info = iio_priv(indio_dev);
+	info->dev = &pdev->dev;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	info->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(info->regs))
+		return PTR_ERR(info->regs);
+
+	info->clk = devm_clk_get(&pdev->dev, "dac");
+	if (IS_ERR(info->clk)) {
+		dev_err(&pdev->dev, "Failed getting clock, err = %ld\n",
+			PTR_ERR(info->clk));
+		return PTR_ERR(info->clk);
+	}
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->info = &vf610_dac_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = vf610_dac_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(vf610_dac_iio_channels);
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Could not prepare or enable the clock\n");
+		return ret;
+	}
+
+	vf610_dac_init(info);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't register the device\n");
+		goto error_iio_device_register;
+	}
+
+	return 0;
+
+error_iio_device_register:
+	clk_disable_unprepare(info->clk);

drivers/iio/dac/vf610_dac.c line 248

Quoted 10 lines
drivers/iio/dac/vf610_dac.c new file +10 -0
+
+	return ret;
+}
+
+static int vf610_dac_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	vf610_dac_exit(info);

Should be reverse order of probe so exit after the unregister below. Right now you are disabling the hardware before removing the userspace interfaces.

Quoted 51 lines
drivers/iio/dac/vf610_dac.c new file +35 -0
+	iio_device_unregister(indio_dev);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int vf610_dac_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+
+	vf610_dac_exit(info);
+	clk_disable_unprepare(info->clk);
+
+	return 0;
+}
+
+static int vf610_dac_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct vf610_dac *info = iio_priv(indio_dev);
+	int ret;
+
+	ret = clk_prepare_enable(info->clk);
+	if (ret)
+		return ret;
+
+	vf610_dac_init(info);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(vf610_dac_pm_ops, vf610_dac_suspend,

vf610_dac_resume);

drivers/iio/dac/vf610_dac.c new file +15 -0
+
+static struct platform_driver vf610_dac_driver = {
+	.probe          = vf610_dac_probe,
+	.remove         = vf610_dac_remove,
+	.driver         = {
+		.name   = "vf610-dac",
+		.of_match_table = vf610_dac_match,
+		.pm     = &vf610_dac_pm_ops,
+	},
+};
+module_platform_driver(vf610_dac_driver);
+
+MODULE_AUTHOR("Sanchayan Maity <[email protected]");
+MODULE_DESCRIPTION("Freescale VF610 DAC driver");
+MODULE_LICENSE("GPL v2");