diff options
Diffstat (limited to 'drivers/iio/dac/vf610_dac.c')
| -rw-r--r-- | drivers/iio/dac/vf610_dac.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/drivers/iio/dac/vf610_dac.c b/drivers/iio/dac/vf610_dac.c new file mode 100644 index 000000000..636b4009f --- /dev/null +++ b/drivers/iio/dac/vf610_dac.c @@ -0,0 +1,288 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Freescale Vybrid vf610 DAC driver + * + * Copyright 2016 Toradex AG + */ + +#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; + struct mutex lock; +}; + +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(&info->lock); + 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(&info->lock); + + 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(&info->lock); + writel(VF610_DAC_DAT0(val), info->regs); + mutex_unlock(&info->lock); + return 0; + + default: + return -EINVAL; + } +} + +static const struct iio_info vf610_dac_iio_info = { + .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; + 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; + + info->regs = devm_platform_ioremap_resource(pdev, 0); + 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->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); + + mutex_init(&info->lock); + + 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: + vf610_dac_exit(info); + 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); + + iio_device_unregister(indio_dev); + vf610_dac_exit(info); + 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"); |