[PATCH v2 2/2] iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC
Jonathan Cameron
jic23 at kernel.org
Sun Feb 21 08:48:20 PST 2016
On 15 February 2016 06:42:33 GMT+00:00, Sanchayan Maity <maitysanchayan at gmail.com> wrote:
>Add driver support for DAC peripheral on Vybrid SoC.
>
>Signed-off-by: Sanchayan Maity <maitysanchayan at gmail.com>
>Acked-by: Rob Herring <robh at 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 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
>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 at 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 at toradex.com");
>+MODULE_DESCRIPTION("Freescale VF610 DAC driver");
>+MODULE_LICENSE("GPL v2");
--
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