[PATCH v2 2/2] iio: dac: vf610_dac: Add IIO DAC driver for Vybrid SoC
Sanchayan Maity
maitysanchayan at gmail.com
Sun Feb 14 22:42:33 PST 2016
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>
---
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);
+ 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");
--
2.7.1
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