[PATCH v2 2/2] iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC
Jonathan Cameron
jic23 at kernel.org
Sun Feb 21 11:37:16 PST 2016
On 21/02/16 16:48, Jonathan Cameron wrote:
>
>
> 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.
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 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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