[PATCH v3 0/4] Support for analog peripherals on LPC18xx familiy

[PATCH v3 0/4] Support for analog peripherals on LPC18xx familiy

[Joachim Eastwood]

This patch set adds support for the analog (ADC and DAC) peripherals
found on NXP LPC18xx/43xx SoCs. The ADC is a SAR converter with 10-bit
resolution and 8 muxed inputs. The DAC is a simple single channel 10-
bit DAC.

Note that these drivers do not support all the features found on the
peripherals. DMA and interrupts are not supported in either drivers.
The ADC driver also lack 'burst-mode' and hardware triggers. So for
now the ADC is limited to single shot samples.

Both drivers tested on Embedded Artists' LPC4357 Developer's Kit.

Based on iio/testing branch.

This version address the comments from Jonathan Cameron and fix the
locking in both the adc and dac driver.

Changes since v2:
 - replace iio dev mlock with a local lock in adc driver
 - add locking to lpc18xx_dac_write_raw() in dac driver
 - rebase on iio/testing

Changes since v1:
 - Fix nits on adc/dac from Peter Meerwald-Stadler
 - Add locking around lpc18xx_adc_read_chan()

Joachim Eastwood (4):
  iio: adc: add NXP LPC18xx ADC driver
  dt: document NXP LPC1850 ADC driver bindings
  iio: dac: add NXP LPC18xx DAC driver
  dt: document NXP LPC1850 DAC driver bindings

 .../devicetree/bindings/iio/adc/lpc1850-adc.txt    |  21 ++
 .../devicetree/bindings/iio/dac/lpc1850-dac.txt    |  20 ++
 drivers/iio/adc/Kconfig                            |  10 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/lpc18xx_adc.c                      | 231 +++++++++++++++++++++
 drivers/iio/dac/Kconfig                            |  10 +
 drivers/iio/dac/Makefile                           |   1 +
 drivers/iio/dac/lpc18xx_dac.c                      | 210 +++++++++++++++++++
 8 files changed, 504 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
 create mode 100644 Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
 create mode 100644 drivers/iio/adc/lpc18xx_adc.c
 create mode 100644 drivers/iio/dac/lpc18xx_dac.c

-- 
1.8.0

[PATCH v3 1/4] iio: adc: add NXP LPC18xx ADC driver

[Joachim Eastwood]

Add base support for the 10-bit SAR ADC peripheral found
on NXP LPC18xx/43xx SoCs.

This is a minimal driver that does not support burst mode,
interrupts, DMA or hardware triggers.

User manual with register description can be found on:
LPC18xx: www.nxp.com/documents/user_manual/UM10430.pdf
LPC43xx: www.nxp.com/documents/user_manual/UM10503.pdf

Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/iio/adc/Kconfig       |  10 ++
 drivers/iio/adc/Makefile      |   1 +
 drivers/iio/adc/lpc18xx_adc.c | 231 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 242 insertions(+)
 create mode 100644 drivers/iio/adc/lpc18xx_adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a8819a08a828..9ddcd5db039b 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -235,6 +235,16 @@ config LP8788_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called lp8788_adc.
 
+config LPC18XX_ADC
+	tristate "NXP LPC18xx ADC driver"
+	depends on ARCH_LPC18XX || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  Say yes here to build support for NXP LPC18XX ADC.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called lpc18xx_adc.
+
 config MAX1027
 	tristate "Maxim max1027 ADC driver"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index b1aa456e6af3..1a4ac4590857 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
 obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
 obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
+obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
 obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
new file mode 100644
index 000000000000..3ef18f4b27f0
--- /dev/null
+++ b/drivers/iio/adc/lpc18xx_adc.c
@@ -0,0 +1,231 @@
+/*
+ * IIO ADC driver for NXP LPC18xx ADC
+ *
+ * Copyright (C) 2016 Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * UNSUPPORTED hardware features:
+ *  - Hardware triggers
+ *  - Burst mode
+ *  - Interrupts
+ *  - DMA
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+/* LPC18XX ADC registers and bits */
+#define LPC18XX_ADC_CR			0x000
+#define  LPC18XX_ADC_CR_CLKDIV_SHIFT	8
+#define  LPC18XX_ADC_CR_PDN		BIT(21)
+#define  LPC18XX_ADC_CR_START_NOW	(0x1 << 24)
+#define LPC18XX_ADC_GDR			0x004
+
+/* Data register bits */
+#define LPC18XX_ADC_SAMPLE_SHIFT	6
+#define LPC18XX_ADC_SAMPLE_MASK		0x3ff
+#define LPC18XX_ADC_CONV_DONE		BIT(31)
+
+/* Clock should be 4.5 MHz or less */
+#define LPC18XX_ADC_CLK_TARGET		4500000
+
+struct lpc18xx_adc {
+	struct regulator *vref;
+	void __iomem *base;
+	struct device *dev;
+	struct mutex lock;
+	struct clk *clk;
+	u32 cr_reg;
+};
+
+#define LPC18XX_ADC_CHAN(_idx) {				\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.channel = _idx,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec lpc18xx_adc_iio_channels[] = {
+	LPC18XX_ADC_CHAN(0),
+	LPC18XX_ADC_CHAN(1),
+	LPC18XX_ADC_CHAN(2),
+	LPC18XX_ADC_CHAN(3),
+	LPC18XX_ADC_CHAN(4),
+	LPC18XX_ADC_CHAN(5),
+	LPC18XX_ADC_CHAN(6),
+	LPC18XX_ADC_CHAN(7),
+};
+
+static int lpc18xx_adc_read_chan(struct lpc18xx_adc *adc, unsigned int ch)
+{
+	int ret;
+	u32 reg;
+
+	reg = adc->cr_reg | BIT(ch) | LPC18XX_ADC_CR_START_NOW;
+	writel(reg, adc->base + LPC18XX_ADC_CR);
+
+	ret = readl_poll_timeout(adc->base + LPC18XX_ADC_GDR, reg,
+				 reg & LPC18XX_ADC_CONV_DONE, 3, 9);
+	if (ret) {
+		dev_warn(adc->dev, "adc read timed out\n");
+		return ret;
+	}
+
+	return (reg >> LPC18XX_ADC_SAMPLE_SHIFT) & LPC18XX_ADC_SAMPLE_MASK;
+}
+
+static int lpc18xx_adc_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct lpc18xx_adc *adc = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&adc->lock);
+		*val = lpc18xx_adc_read_chan(adc, chan->channel);
+		mutex_unlock(&adc->lock);
+		if (*val < 0)
+			return *val;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = regulator_get_voltage(adc->vref) / 1000;
+		*val2 = 10;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info lpc18xx_adc_info = {
+	.read_raw = lpc18xx_adc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int lpc18xx_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct lpc18xx_adc *adc;
+	struct resource *res;
+	unsigned int clkdiv;
+	unsigned long rate;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, indio_dev);
+	adc = iio_priv(indio_dev);
+	adc->dev = &pdev->dev;
+	mutex_init(&adc->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	adc->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(adc->base))
+		return PTR_ERR(adc->base);
+
+	adc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(adc->clk)) {
+		dev_err(&pdev->dev, "error getting clock\n");
+		return PTR_ERR(adc->clk);
+	}
+
+	rate = clk_get_rate(adc->clk);
+	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
+
+	adc->vref = devm_regulator_get(&pdev->dev, "vref");
+	if (IS_ERR(adc->vref)) {
+		dev_err(&pdev->dev, "error getting regulator\n");
+		return PTR_ERR(adc->vref);
+	}
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &lpc18xx_adc_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = lpc18xx_adc_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(lpc18xx_adc_iio_channels);
+
+	ret = regulator_enable(adc->vref);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable regulator\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(adc->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		goto dis_reg;
+	}
+
+	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
+			LPC18XX_ADC_CR_PDN;
+	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to register device\n");
+		goto dis_clk;
+	}
+
+	return 0;
+
+dis_clk:
+	writel(0, adc->base + LPC18XX_ADC_CR);
+	clk_disable_unprepare(adc->clk);
+dis_reg:
+	regulator_disable(adc->vref);
+	return ret;
+}
+
+static int lpc18xx_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct lpc18xx_adc *adc = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	writel(0, adc->base + LPC18XX_ADC_CR);
+	clk_disable_unprepare(adc->clk);
+	regulator_disable(adc->vref);
+
+	return 0;
+}
+
+static const struct of_device_id lpc18xx_adc_match[] = {
+	{ .compatible = "nxp,lpc1850-adc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_adc_match);
+
+static struct platform_driver lpc18xx_adc_driver = {
+	.probe	= lpc18xx_adc_probe,
+	.remove	= lpc18xx_adc_remove,
+	.driver	= {
+		.name = "lpc18xx-adc",
+		.of_match_table = lpc18xx_adc_match,
+	},
+};
+module_platform_driver(lpc18xx_adc_driver);
+
+MODULE_DESCRIPTION("LPC18xx ADC driver");
+MODULE_AUTHOR("Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
-- 
1.8.0

[PATCH v3 2/4] dt: document NXP LPC1850 ADC driver bindings

[Joachim Eastwood]

Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/iio/adc/lpc1850-adc.txt     | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt

diff --git a/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt b/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
new file mode 100644
index 000000000000..0bcae5140bc5
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
@@ -0,0 +1,21 @@
+NXP LPC1850 ADC bindings
+
+Required properties:
+- compatible: Should be "nxp,lpc1850-adc"
+- reg: Offset and length of the register set for the ADC device
+- interrupts: The interrupt number for the ADC device
+- clocks: The root clock of the ADC controller
+- vref-supply: The regulator supply ADC reference voltage
+- resets: phandle to reset controller and line specifier
+
+Example:
+
+adc0: adc@400e3000 {
+	compatible = "nxp,lpc1850-adc";
+	reg = <0x400e3000 0x1000>;
+	interrupts = <17>;
+	clocks = <&ccu1 CLK_APB3_ADC0>;
+	vref-supply = <&reg_vdda>;
+	resets = <&rgu 40>;
+	status = "disabled";
+};
-- 
1.8.0

[PATCH v3 3/4] iio: dac: add NXP LPC18xx DAC driver

[Joachim Eastwood]

Add base support for the 10-bit DAC peripheral found
on NXP LPC18xx/43xx SoCs.

This is a minimal driver that does not support DMA or
interrupts.

User manual with register description can be found on:
LPC18xx: www.nxp.com/documents/user_manual/UM10430.pdf
LPC43xx: www.nxp.com/documents/user_manual/UM10503.pdf

Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/iio/dac/Kconfig       |  10 ++
 drivers/iio/dac/Makefile      |   1 +
 drivers/iio/dac/lpc18xx_dac.c | 210 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 221 insertions(+)
 create mode 100644 drivers/iio/dac/lpc18xx_dac.c

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index a995139f907c..210db81ca144 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -154,6 +154,16 @@ config AD7303
 	  To compile this driver as module choose M here: the module will be called
 	  ad7303.
 
+config LPC18XX_DAC
+	tristate "NXP LPC18xx DAC driver"
+	depends on ARCH_LPC18XX || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	help
+	  Say yes here to build support for NXP LPC18XX DAC.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called lpc18xx_dac.
+
 config M62332
 	tristate "Mitsubishi M62332 DAC driver"
 	depends on I2C
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 67b48429686d..420a15cdaa53 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o
 obj-$(CONFIG_AD7303) += ad7303.o
+obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
 obj-$(CONFIG_M62332) += m62332.o
 obj-$(CONFIG_MAX517) += max517.o
 obj-$(CONFIG_MAX5821) += max5821.o
diff --git a/drivers/iio/dac/lpc18xx_dac.c b/drivers/iio/dac/lpc18xx_dac.c
new file mode 100644
index 000000000000..55d1456a059d
--- /dev/null
+++ b/drivers/iio/dac/lpc18xx_dac.c
@@ -0,0 +1,210 @@
+/*
+ * IIO DAC driver for NXP LPC18xx DAC
+ *
+ * Copyright (C) 2016 Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * UNSUPPORTED hardware features:
+ *  - Interrupts
+ *  - DMA
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+/* LPC18XX DAC registers and bits */
+#define LPC18XX_DAC_CR			0x000
+#define  LPC18XX_DAC_CR_VALUE_SHIFT	6
+#define  LPC18XX_DAC_CR_VALUE_MASK	0x3ff
+#define  LPC18XX_DAC_CR_BIAS		BIT(16)
+#define LPC18XX_DAC_CTRL		0x004
+#define  LPC18XX_DAC_CTRL_DMA_ENA	BIT(3)
+
+struct lpc18xx_dac {
+	struct regulator *vref;
+	void __iomem *base;
+	struct mutex lock;
+	struct clk *clk;
+};
+
+static const struct iio_chan_spec lpc18xx_dac_iio_channels[] = {
+	{
+		.type = IIO_VOLTAGE,
+		.output = 1,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static int lpc18xx_dac_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct lpc18xx_dac *dac = iio_priv(indio_dev);
+	u32 reg;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		reg = readl(dac->base + LPC18XX_DAC_CR);
+		*val = reg >> LPC18XX_DAC_CR_VALUE_SHIFT;
+		*val &= LPC18XX_DAC_CR_VALUE_MASK;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = regulator_get_voltage(dac->vref) / 1000;
+		*val2 = 10;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+
+	return -EINVAL;
+}
+
+static int lpc18xx_dac_write_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int val, int val2, long mask)
+{
+	struct lpc18xx_dac *dac = iio_priv(indio_dev);
+	u32 reg;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (val < 0 || val > LPC18XX_DAC_CR_VALUE_MASK)
+			return -EINVAL;
+
+		reg = LPC18XX_DAC_CR_BIAS;
+		reg |= val << LPC18XX_DAC_CR_VALUE_SHIFT;
+
+		mutex_lock(&dac->lock);
+		writel(reg, dac->base + LPC18XX_DAC_CR);
+		writel(LPC18XX_DAC_CTRL_DMA_ENA, dac->base + LPC18XX_DAC_CTRL);
+		mutex_unlock(&dac->lock);
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info lpc18xx_dac_info = {
+	.read_raw = lpc18xx_dac_read_raw,
+	.write_raw = lpc18xx_dac_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int lpc18xx_dac_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct lpc18xx_dac *dac;
+	struct resource *res;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*dac));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, indio_dev);
+	dac = iio_priv(indio_dev);
+	mutex_init(&dac->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dac->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dac->base))
+		return PTR_ERR(dac->base);
+
+	dac->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dac->clk)) {
+		dev_err(&pdev->dev, "error getting clock\n");
+		return PTR_ERR(dac->clk);
+	}
+
+	dac->vref = devm_regulator_get(&pdev->dev, "vref");
+	if (IS_ERR(dac->vref)) {
+		dev_err(&pdev->dev, "error getting regulator\n");
+		return PTR_ERR(dac->vref);
+	}
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &lpc18xx_dac_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = lpc18xx_dac_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(lpc18xx_dac_iio_channels);
+
+	ret = regulator_enable(dac->vref);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable regulator\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(dac->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to enable clock\n");
+		goto dis_reg;
+	}
+
+	writel(0, dac->base + LPC18XX_DAC_CTRL);
+	writel(0, dac->base + LPC18XX_DAC_CR);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to register device\n");
+		goto dis_clk;
+	}
+
+	return 0;
+
+dis_clk:
+	clk_disable_unprepare(dac->clk);
+dis_reg:
+	regulator_disable(dac->vref);
+	return ret;
+}
+
+static int lpc18xx_dac_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct lpc18xx_dac *dac = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	writel(0, dac->base + LPC18XX_DAC_CTRL);
+	clk_disable_unprepare(dac->clk);
+	regulator_disable(dac->vref);
+
+	return 0;
+}
+
+static const struct of_device_id lpc18xx_dac_match[] = {
+	{ .compatible = "nxp,lpc1850-dac" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_dac_match);
+
+static struct platform_driver lpc18xx_dac_driver = {
+	.probe	= lpc18xx_dac_probe,
+	.remove	= lpc18xx_dac_remove,
+	.driver	= {
+		.name = "lpc18xx-dac",
+		.of_match_table = lpc18xx_dac_match,
+	},
+};
+module_platform_driver(lpc18xx_dac_driver);
+
+MODULE_DESCRIPTION("LPC18xx DAC driver");
+MODULE_AUTHOR("Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
-- 
1.8.0

[PATCH v3 4/4] dt: document NXP LPC1850 DAC driver bindings

[Joachim Eastwood]

Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/iio/dac/lpc1850-dac.txt      | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt

diff --git a/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt b/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
new file mode 100644
index 000000000000..7d6647d4af5e
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
@@ -0,0 +1,20 @@
+NXP LPC1850 DAC bindings
+
+Required properties:
+- compatible: Should be "nxp,lpc1850-dac"
+- reg: Offset and length of the register set for the ADC device
+- interrupts: The interrupt number for the ADC device
+- clocks: The root clock of the ADC controller
+- vref-supply: The regulator supply ADC reference voltage
+- resets: phandle to reset controller and line specifier
+
+Example:
+dac: dac@400e1000 {
+	compatible = "nxp,lpc1850-dac";
+	reg = <0x400e1000 0x1000>;
+	interrupts = <0>;
+	clocks = <&ccu1 CLK_APB3_DAC>;
+	vref-supply = <&reg_vdda>;
+	resets = <&rgu 42>;
+	status = "disabled";
+};
-- 
1.8.0

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Re: [PATCH v3 1/4] iio: adc: add NXP LPC18xx ADC driver

[Jonathan Cameron]

On 12/03/16 12:30, Joachim Eastwood wrote:
> Add base support for the 10-bit SAR ADC peripheral found
> on NXP LPC18xx/43xx SoCs.
> 
> This is a minimal driver that does not support burst mode,
> interrupts, DMA or hardware triggers.
> 
> User manual with register description can be found on:
> LPC18xx: www.nxp.com/documents/user_manual/UM10430.pdf
> LPC43xx: www.nxp.com/documents/user_manual/UM10503.pdf
> 
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Applied to the togreg branch of iio.git - initially pushed out as
testing for the autobuilders to play with it.

Thanks,

Jonathan
> ---
>  drivers/iio/adc/Kconfig       |  10 ++
>  drivers/iio/adc/Makefile      |   1 +
>  drivers/iio/adc/lpc18xx_adc.c | 231 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 242 insertions(+)
>  create mode 100644 drivers/iio/adc/lpc18xx_adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index a8819a08a828..9ddcd5db039b 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -235,6 +235,16 @@ config LP8788_ADC
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called lp8788_adc.
>  
> +config LPC18XX_ADC
> +	tristate "NXP LPC18xx ADC driver"
> +	depends on ARCH_LPC18XX || COMPILE_TEST
> +	depends on OF && HAS_IOMEM
> +	help
> +	  Say yes here to build support for NXP LPC18XX ADC.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called lpc18xx_adc.
> +
>  config MAX1027
>  	tristate "Maxim max1027 ADC driver"
>  	depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index b1aa456e6af3..1a4ac4590857 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
>  obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
>  obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
>  obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
> +obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
>  obj-$(CONFIG_MAX1027) += max1027.o
>  obj-$(CONFIG_MAX1363) += max1363.o
>  obj-$(CONFIG_MCP320X) += mcp320x.o
> diff --git a/drivers/iio/adc/lpc18xx_adc.c b/drivers/iio/adc/lpc18xx_adc.c
> new file mode 100644
> index 000000000000..3ef18f4b27f0
> --- /dev/null
> +++ b/drivers/iio/adc/lpc18xx_adc.c
> @@ -0,0 +1,231 @@
> +/*
> + * IIO ADC driver for NXP LPC18xx ADC
> + *
> + * Copyright (C) 2016 Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * UNSUPPORTED hardware features:
> + *  - Hardware triggers
> + *  - Burst mode
> + *  - Interrupts
> + *  - DMA
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +
> +/* LPC18XX ADC registers and bits */
> +#define LPC18XX_ADC_CR			0x000
> +#define  LPC18XX_ADC_CR_CLKDIV_SHIFT	8
> +#define  LPC18XX_ADC_CR_PDN		BIT(21)
> +#define  LPC18XX_ADC_CR_START_NOW	(0x1 << 24)
> +#define LPC18XX_ADC_GDR			0x004
> +
> +/* Data register bits */
> +#define LPC18XX_ADC_SAMPLE_SHIFT	6
> +#define LPC18XX_ADC_SAMPLE_MASK		0x3ff
> +#define LPC18XX_ADC_CONV_DONE		BIT(31)
> +
> +/* Clock should be 4.5 MHz or less */
> +#define LPC18XX_ADC_CLK_TARGET		4500000
> +
> +struct lpc18xx_adc {
> +	struct regulator *vref;
> +	void __iomem *base;
> +	struct device *dev;
> +	struct mutex lock;
> +	struct clk *clk;
> +	u32 cr_reg;
> +};
> +
> +#define LPC18XX_ADC_CHAN(_idx) {				\
> +	.type = IIO_VOLTAGE,					\
> +	.indexed = 1,						\
> +	.channel = _idx,					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +}
> +
> +static const struct iio_chan_spec lpc18xx_adc_iio_channels[] = {
> +	LPC18XX_ADC_CHAN(0),
> +	LPC18XX_ADC_CHAN(1),
> +	LPC18XX_ADC_CHAN(2),
> +	LPC18XX_ADC_CHAN(3),
> +	LPC18XX_ADC_CHAN(4),
> +	LPC18XX_ADC_CHAN(5),
> +	LPC18XX_ADC_CHAN(6),
> +	LPC18XX_ADC_CHAN(7),
> +};
> +
> +static int lpc18xx_adc_read_chan(struct lpc18xx_adc *adc, unsigned int ch)
> +{
> +	int ret;
> +	u32 reg;
> +
> +	reg = adc->cr_reg | BIT(ch) | LPC18XX_ADC_CR_START_NOW;
> +	writel(reg, adc->base + LPC18XX_ADC_CR);
> +
> +	ret = readl_poll_timeout(adc->base + LPC18XX_ADC_GDR, reg,
> +				 reg & LPC18XX_ADC_CONV_DONE, 3, 9);
> +	if (ret) {
> +		dev_warn(adc->dev, "adc read timed out\n");
> +		return ret;
> +	}
> +
> +	return (reg >> LPC18XX_ADC_SAMPLE_SHIFT) & LPC18XX_ADC_SAMPLE_MASK;
> +}
> +
> +static int lpc18xx_adc_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	struct lpc18xx_adc *adc = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&adc->lock);
> +		*val = lpc18xx_adc_read_chan(adc, chan->channel);
> +		mutex_unlock(&adc->lock);
> +		if (*val < 0)
> +			return *val;
> +
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = regulator_get_voltage(adc->vref) / 1000;
> +		*val2 = 10;
> +
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info lpc18xx_adc_info = {
> +	.read_raw = lpc18xx_adc_read_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int lpc18xx_adc_probe(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev;
> +	struct lpc18xx_adc *adc;
> +	struct resource *res;
> +	unsigned int clkdiv;
> +	unsigned long rate;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +	adc = iio_priv(indio_dev);
> +	adc->dev = &pdev->dev;
> +	mutex_init(&adc->lock);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	adc->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(adc->base))
> +		return PTR_ERR(adc->base);
> +
> +	adc->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(adc->clk)) {
> +		dev_err(&pdev->dev, "error getting clock\n");
> +		return PTR_ERR(adc->clk);
> +	}
> +
> +	rate = clk_get_rate(adc->clk);
> +	clkdiv = DIV_ROUND_UP(rate, LPC18XX_ADC_CLK_TARGET);
> +
> +	adc->vref = devm_regulator_get(&pdev->dev, "vref");
> +	if (IS_ERR(adc->vref)) {
> +		dev_err(&pdev->dev, "error getting regulator\n");
> +		return PTR_ERR(adc->vref);
> +	}
> +
> +	indio_dev->name = dev_name(&pdev->dev);
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &lpc18xx_adc_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = lpc18xx_adc_iio_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(lpc18xx_adc_iio_channels);
> +
> +	ret = regulator_enable(adc->vref);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to enable regulator\n");
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(adc->clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to enable clock\n");
> +		goto dis_reg;
> +	}
> +
> +	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |
> +			LPC18XX_ADC_CR_PDN;
> +	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to register device\n");
> +		goto dis_clk;
> +	}
> +
> +	return 0;
> +
> +dis_clk:
> +	writel(0, adc->base + LPC18XX_ADC_CR);
> +	clk_disable_unprepare(adc->clk);
> +dis_reg:
> +	regulator_disable(adc->vref);
> +	return ret;
> +}
> +
> +static int lpc18xx_adc_remove(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +	struct lpc18xx_adc *adc = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	writel(0, adc->base + LPC18XX_ADC_CR);
> +	clk_disable_unprepare(adc->clk);
> +	regulator_disable(adc->vref);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id lpc18xx_adc_match[] = {
> +	{ .compatible = "nxp,lpc1850-adc" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, lpc18xx_adc_match);
> +
> +static struct platform_driver lpc18xx_adc_driver = {
> +	.probe	= lpc18xx_adc_probe,
> +	.remove	= lpc18xx_adc_remove,
> +	.driver	= {
> +		.name = "lpc18xx-adc",
> +		.of_match_table = lpc18xx_adc_match,
> +	},
> +};
> +module_platform_driver(lpc18xx_adc_driver);
> +
> +MODULE_DESCRIPTION("LPC18xx ADC driver");
> +MODULE_AUTHOR("Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v3 2/4] dt: document NXP LPC1850 ADC driver bindings

[Jonathan Cameron]

On 12/03/16 12:30, Joachim Eastwood wrote:
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Applied.
> ---
>  .../devicetree/bindings/iio/adc/lpc1850-adc.txt     | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt b/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
> new file mode 100644
> index 000000000000..0bcae5140bc5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/lpc1850-adc.txt
> @@ -0,0 +1,21 @@
> +NXP LPC1850 ADC bindings
> +
> +Required properties:
> +- compatible: Should be "nxp,lpc1850-adc"
> +- reg: Offset and length of the register set for the ADC device
> +- interrupts: The interrupt number for the ADC device
> +- clocks: The root clock of the ADC controller
> +- vref-supply: The regulator supply ADC reference voltage
> +- resets: phandle to reset controller and line specifier
> +
> +Example:
> +
> +adc0: adc@400e3000 {
> +	compatible = "nxp,lpc1850-adc";
> +	reg = <0x400e3000 0x1000>;
> +	interrupts = <17>;
> +	clocks = <&ccu1 CLK_APB3_ADC0>;
> +	vref-supply = <&reg_vdda>;
> +	resets = <&rgu 40>;
> +	status = "disabled";
> +};
> 

Re: [PATCH v3 3/4] iio: dac: add NXP LPC18xx DAC driver

[Jonathan Cameron]

On 12/03/16 12:30, Joachim Eastwood wrote:
> Add base support for the 10-bit DAC peripheral found
> on NXP LPC18xx/43xx SoCs.
> 
> This is a minimal driver that does not support DMA or
> interrupts.
> 
> User manual with register description can be found on:
> LPC18xx: www.nxp.com/documents/user_manual/UM10430.pdf
> LPC43xx: www.nxp.com/documents/user_manual/UM10503.pdf
> 
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Applied.
> ---
>  drivers/iio/dac/Kconfig       |  10 ++
>  drivers/iio/dac/Makefile      |   1 +
>  drivers/iio/dac/lpc18xx_dac.c | 210 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 221 insertions(+)
>  create mode 100644 drivers/iio/dac/lpc18xx_dac.c
> 
> diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
> index a995139f907c..210db81ca144 100644
> --- a/drivers/iio/dac/Kconfig
> +++ b/drivers/iio/dac/Kconfig
> @@ -154,6 +154,16 @@ config AD7303
>  	  To compile this driver as module choose M here: the module will be called
>  	  ad7303.
>  
> +config LPC18XX_DAC
> +	tristate "NXP LPC18xx DAC driver"
> +	depends on ARCH_LPC18XX || COMPILE_TEST
> +	depends on OF && HAS_IOMEM
> +	help
> +	  Say yes here to build support for NXP LPC18XX DAC.
> +
> +	  To compile this driver as a module, choose M here: the module will be
> +	  called lpc18xx_dac.
> +
>  config M62332
>  	tristate "Mitsubishi M62332 DAC driver"
>  	depends on I2C
> diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
> index 67b48429686d..420a15cdaa53 100644
> --- a/drivers/iio/dac/Makefile
> +++ b/drivers/iio/dac/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_AD5764) += ad5764.o
>  obj-$(CONFIG_AD5791) += ad5791.o
>  obj-$(CONFIG_AD5686) += ad5686.o
>  obj-$(CONFIG_AD7303) += ad7303.o
> +obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
>  obj-$(CONFIG_M62332) += m62332.o
>  obj-$(CONFIG_MAX517) += max517.o
>  obj-$(CONFIG_MAX5821) += max5821.o
> diff --git a/drivers/iio/dac/lpc18xx_dac.c b/drivers/iio/dac/lpc18xx_dac.c
> new file mode 100644
> index 000000000000..55d1456a059d
> --- /dev/null
> +++ b/drivers/iio/dac/lpc18xx_dac.c
> @@ -0,0 +1,210 @@
> +/*
> + * IIO DAC driver for NXP LPC18xx DAC
> + *
> + * Copyright (C) 2016 Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * UNSUPPORTED hardware features:
> + *  - Interrupts
> + *  - DMA
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/driver.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> +
> +/* LPC18XX DAC registers and bits */
> +#define LPC18XX_DAC_CR			0x000
> +#define  LPC18XX_DAC_CR_VALUE_SHIFT	6
> +#define  LPC18XX_DAC_CR_VALUE_MASK	0x3ff
> +#define  LPC18XX_DAC_CR_BIAS		BIT(16)
> +#define LPC18XX_DAC_CTRL		0x004
> +#define  LPC18XX_DAC_CTRL_DMA_ENA	BIT(3)
> +
> +struct lpc18xx_dac {
> +	struct regulator *vref;
> +	void __iomem *base;
> +	struct mutex lock;
> +	struct clk *clk;
> +};
> +
> +static const struct iio_chan_spec lpc18xx_dac_iio_channels[] = {
> +	{
> +		.type = IIO_VOLTAGE,
> +		.output = 1,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE),
> +	},
> +};
> +
> +static int lpc18xx_dac_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	struct lpc18xx_dac *dac = iio_priv(indio_dev);
> +	u32 reg;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		reg = readl(dac->base + LPC18XX_DAC_CR);
> +		*val = reg >> LPC18XX_DAC_CR_VALUE_SHIFT;
> +		*val &= LPC18XX_DAC_CR_VALUE_MASK;
> +
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = regulator_get_voltage(dac->vref) / 1000;
> +		*val2 = 10;
> +
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int lpc18xx_dac_write_raw(struct iio_dev *indio_dev,
> +				 struct iio_chan_spec const *chan,
> +				 int val, int val2, long mask)
> +{
> +	struct lpc18xx_dac *dac = iio_priv(indio_dev);
> +	u32 reg;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (val < 0 || val > LPC18XX_DAC_CR_VALUE_MASK)
> +			return -EINVAL;
> +
> +		reg = LPC18XX_DAC_CR_BIAS;
> +		reg |= val << LPC18XX_DAC_CR_VALUE_SHIFT;
> +
> +		mutex_lock(&dac->lock);
> +		writel(reg, dac->base + LPC18XX_DAC_CR);
> +		writel(LPC18XX_DAC_CTRL_DMA_ENA, dac->base + LPC18XX_DAC_CTRL);
> +		mutex_unlock(&dac->lock);
> +
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info lpc18xx_dac_info = {
> +	.read_raw = lpc18xx_dac_read_raw,
> +	.write_raw = lpc18xx_dac_write_raw,
> +	.driver_module = THIS_MODULE,
> +};
> +
> +static int lpc18xx_dac_probe(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev;
> +	struct lpc18xx_dac *dac;
> +	struct resource *res;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*dac));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, indio_dev);
> +	dac = iio_priv(indio_dev);
> +	mutex_init(&dac->lock);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	dac->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(dac->base))
> +		return PTR_ERR(dac->base);
> +
> +	dac->clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(dac->clk)) {
> +		dev_err(&pdev->dev, "error getting clock\n");
> +		return PTR_ERR(dac->clk);
> +	}
> +
> +	dac->vref = devm_regulator_get(&pdev->dev, "vref");
> +	if (IS_ERR(dac->vref)) {
> +		dev_err(&pdev->dev, "error getting regulator\n");
> +		return PTR_ERR(dac->vref);
> +	}
> +
> +	indio_dev->name = dev_name(&pdev->dev);
> +	indio_dev->dev.parent = &pdev->dev;
> +	indio_dev->info = &lpc18xx_dac_info;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = lpc18xx_dac_iio_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(lpc18xx_dac_iio_channels);
> +
> +	ret = regulator_enable(dac->vref);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to enable regulator\n");
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(dac->clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to enable clock\n");
> +		goto dis_reg;
> +	}
> +
> +	writel(0, dac->base + LPC18XX_DAC_CTRL);
> +	writel(0, dac->base + LPC18XX_DAC_CR);
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "unable to register device\n");
> +		goto dis_clk;
> +	}
> +
> +	return 0;
> +
> +dis_clk:
> +	clk_disable_unprepare(dac->clk);
> +dis_reg:
> +	regulator_disable(dac->vref);
> +	return ret;
> +}
> +
> +static int lpc18xx_dac_remove(struct platform_device *pdev)
> +{
> +	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> +	struct lpc18xx_dac *dac = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	writel(0, dac->base + LPC18XX_DAC_CTRL);
> +	clk_disable_unprepare(dac->clk);
> +	regulator_disable(dac->vref);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id lpc18xx_dac_match[] = {
> +	{ .compatible = "nxp,lpc1850-dac" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, lpc18xx_dac_match);
> +
> +static struct platform_driver lpc18xx_dac_driver = {
> +	.probe	= lpc18xx_dac_probe,
> +	.remove	= lpc18xx_dac_remove,
> +	.driver	= {
> +		.name = "lpc18xx-dac",
> +		.of_match_table = lpc18xx_dac_match,
> +	},
> +};
> +module_platform_driver(lpc18xx_dac_driver);
> +
> +MODULE_DESCRIPTION("LPC18xx DAC driver");
> +MODULE_AUTHOR("Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
> +MODULE_LICENSE("GPL v2");
> 

Re: [PATCH v3 4/4] dt: document NXP LPC1850 DAC driver bindings

[Jonathan Cameron]

On 12/03/16 12:30, Joachim Eastwood wrote:
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
A very straight forward binding so I'm happy to apply this without
a devicetree ack (still time if anyone does want to take a look though as
it won't be in my non rebasing tree until probably next weekend now.)

Applied to the togreg branch of iio.git - initially pushed out as testing
for the autobuilders to play with it.

We have unfortunately missed the merge window that will probably open tomorrow
(as IIO stuff must be in a few weeks before that) so this is looking at the
next merge window in 3 months time.  Will be in linux-next in about 3-4 weeks
though after I send a pull request to Greg KH post merge window closing.

Thanks,

Jonathan
> ---
>  .../devicetree/bindings/iio/dac/lpc1850-dac.txt      | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
> 
> diff --git a/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt b/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
> new file mode 100644
> index 000000000000..7d6647d4af5e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt
> @@ -0,0 +1,20 @@
> +NXP LPC1850 DAC bindings
> +
> +Required properties:
> +- compatible: Should be "nxp,lpc1850-dac"
> +- reg: Offset and length of the register set for the ADC device
> +- interrupts: The interrupt number for the ADC device
> +- clocks: The root clock of the ADC controller
> +- vref-supply: The regulator supply ADC reference voltage
> +- resets: phandle to reset controller and line specifier
> +
> +Example:
> +dac: dac@400e1000 {
> +	compatible = "nxp,lpc1850-dac";
> +	reg = <0x400e1000 0x1000>;
> +	interrupts = <0>;
> +	clocks = <&ccu1 CLK_APB3_DAC>;
> +	vref-supply = <&reg_vdda>;
> +	resets = <&rgu 42>;
> +	status = "disabled";
> +};
> 

Re: [PATCH v3 4/4] dt: document NXP LPC1850 DAC driver bindings

[Joachim Eastwood]

Hi Jonathan,

On 12 March 2016 at 19:17, Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> On 12/03/16 12:30, Joachim Eastwood wrote:
>> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> A very straight forward binding so I'm happy to apply this without
> a devicetree ack (still time if anyone does want to take a look though as
> it won't be in my non rebasing tree until probably next weekend now.)
>
> Applied to the togreg branch of iio.git - initially pushed out as testing
> for the autobuilders to play with it.

Thanks!

> We have unfortunately missed the merge window that will probably open tomorrow
> (as IIO stuff must be in a few weeks before that) so this is looking at the
> next merge window in 3 months time.  Will be in linux-next in about 3-4 weeks
> though after I send a pull request to Greg KH post merge window closing.
I wasn't expecting it to go upstream in the upcoming window. But I
will be good to get it into next after the window closes so I can get
the DT bits for lpc18xx upstream as well.


regards,
Joachim Eastwood

Re: [PATCH v3 4/4] dt: document NXP LPC1850 DAC driver bindings

[Rob Herring]

On Sat, Mar 12, 2016 at 01:30:17PM +0100, Joachim Eastwood wrote:
> Signed-off-by: Joachim Eastwood <manabian-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> ---
>  .../devicetree/bindings/iio/dac/lpc1850-dac.txt      | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/dac/lpc1850-dac.txt

Acked-by: Rob Herring <robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>