[PATCH v2 0/2] Add DAC driver support for Vybrid SoC

[PATCH v2 0/2] Add DAC driver support for Vybrid SoC

[Sanchayan Maity]

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

-- 
2.7.1

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

[Sanchayan Maity]

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

Signed-off-by: Sanchayan Maity <maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 arch/arm/boot/dts/vfxxx.dtsi | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/arm/boot/dts/vfxxx.dtsi b/arch/arm/boot/dts/vfxxx.dtsi
index a5f07e3..8238069 100644
--- a/arch/arm/boot/dts/vfxxx.dtsi
+++ b/arch/arm/boot/dts/vfxxx.dtsi
@@ -602,6 +602,24 @@
 				status = "disabled";
 			};
 
+			dac0: dac@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@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@400d0000 {
 				compatible = "fsl,mvf600-fec";
 				reg = <0x400d0000 0x1000>;
-- 
2.7.1

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

[Sanchayan Maity]

Add driver support for DAC peripheral on Vybrid SoC.

Signed-off-by: Sanchayan Maity <maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 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

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-vf610 b/Documentation/ABI/testing/sysfs-bus-iio-vf610
index ecbc1f4..5ea809c 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio-vf610
+++ b/Documentation/ABI/testing/sysfs-bus-iio-vf610
@@ -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-u79uwXL29TY76Z2rM5mHXA@public.gmane.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
diff --git a/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
new file mode 100644
index 0000000..20c6c7a
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
@@ -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@400cc000 {
+	compatible = "fsl,vf610-dac";
+	reg = <0x400cc000 0x1000>;
+	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
+	clock-names = "dac";
+	clocks = <&clks VF610_CLK_DAC0>;
+};
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index e701e28..8eb0502 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -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
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 63ae056..93feb27 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -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
diff --git a/drivers/iio/dac/vf610_dac.c b/drivers/iio/dac/vf610_dac.c
new file mode 100644
index 0000000..3f70f96
--- /dev/null
+++ b/drivers/iio/dac/vf610_dac.c
@@ -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.
+ */
+
+#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" };
+
+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);
+
+	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);
+	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);
+
+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 <sanchayan.maity-2KBjVHiyJgBBDgjK7y7TUQ@public.gmane.org");
+MODULE_DESCRIPTION("Freescale VF610 DAC driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.1

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

[Jonathan Cameron]

On 15 February 2016 06:42:33 GMT+00:00, Sanchayan Maity <maitysanchayan@gmail.com> wrote:
>Add driver support for DAC peripheral on Vybrid SoC.
>
>Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
>Acked-by: Rob Herring <robh@kernel.org>
Ordering is wrong in remove. I may well fix this up and apply later today. 
 Otherwise looks good to me.
>---
> 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
>
>diff --git a/Documentation/ABI/testing/sysfs-bus-iio-vf610
>b/Documentation/ABI/testing/sysfs-bus-iio-vf610
>index ecbc1f4..5ea809c 100644
>--- a/Documentation/ABI/testing/sysfs-bus-iio-vf610
>+++ b/Documentation/ABI/testing/sysfs-bus-iio-vf610
>@@ -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@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
>diff --git a/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>new file mode 100644
>index 0000000..20c6c7a
>--- /dev/null
>+++ b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>@@ -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@400cc000 {
>+	compatible = "fsl,vf610-dac";
>+	reg = <0x400cc000 0x1000>;
>+	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
>+	clock-names = "dac";
>+	clocks = <&clks VF610_CLK_DAC0>;
>+};
>diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
>index e701e28..8eb0502 100644
>--- a/drivers/iio/dac/Kconfig
>+++ b/drivers/iio/dac/Kconfig
>@@ -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
>diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
>index 63ae056..93feb27 100644
>--- a/drivers/iio/dac/Makefile
>+++ b/drivers/iio/dac/Makefile
>@@ -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
>diff --git a/drivers/iio/dac/vf610_dac.c b/drivers/iio/dac/vf610_dac.c
>new file mode 100644
>index 0000000..3f70f96
>--- /dev/null
>+++ b/drivers/iio/dac/vf610_dac.c
>@@ -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.
>+ */
>+
>+#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" };
>+
>+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);
>+
>+	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.
>+	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);
>+
>+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 <sanchayan.maity@toradex.com");
>+MODULE_DESCRIPTION("Freescale VF610 DAC driver");
>+MODULE_LICENSE("GPL v2");

-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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

[Jonathan Cameron]

On 21/02/16 16:48, Jonathan Cameron wrote:
> 
> 
> On 15 February 2016 06:42:33 GMT+00:00, Sanchayan Maity <maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
>> Add driver support for DAC peripheral on Vybrid SoC.
>>
>> Signed-off-by: Sanchayan Maity <maitysanchayan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> 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
>  Otherwise looks good to me.
>> ---
>> 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
>>
>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-vf610
>> b/Documentation/ABI/testing/sysfs-bus-iio-vf610
>> index ecbc1f4..5ea809c 100644
>> --- a/Documentation/ABI/testing/sysfs-bus-iio-vf610
>> +++ b/Documentation/ABI/testing/sysfs-bus-iio-vf610
>> @@ -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-u79uwXL29TY76Z2rM5mHXA@public.gmane.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
>> diff --git a/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>> b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>> new file mode 100644
>> index 0000000..20c6c7a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/dac/vf610-dac.txt
>> @@ -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@400cc000 {
>> +	compatible = "fsl,vf610-dac";
>> +	reg = <0x400cc000 0x1000>;
>> +	interrupts = <55 IRQ_TYPE_LEVEL_HIGH>;
>> +	clock-names = "dac";
>> +	clocks = <&clks VF610_CLK_DAC0>;
>> +};
>> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
>> index e701e28..8eb0502 100644
>> --- a/drivers/iio/dac/Kconfig
>> +++ b/drivers/iio/dac/Kconfig
>> @@ -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
>> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
>> index 63ae056..93feb27 100644
>> --- a/drivers/iio/dac/Makefile
>> +++ b/drivers/iio/dac/Makefile
>> @@ -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
>> diff --git a/drivers/iio/dac/vf610_dac.c b/drivers/iio/dac/vf610_dac.c
>> new file mode 100644
>> index 0000000..3f70f96
>> --- /dev/null
>> +++ b/drivers/iio/dac/vf610_dac.c
>> @@ -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.
>> + */
>> +
>> +#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" };
>> +
>> +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);
>> +
>> +	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.
>> +	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);
>> +
>> +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 <sanchayan.maity-2KBjVHiyJgBBDgjK7y7TUQ@public.gmane.org");
>> +MODULE_DESCRIPTION("Freescale VF610 DAC driver");
>> +MODULE_LICENSE("GPL v2");
>