summaryrefslogtreecommitdiff
path: root/drivers/iio
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/dac/Kconfig15
-rw-r--r--drivers/iio/dac/Makefile2
-rw-r--r--drivers/iio/dac/stm32-dac-core.c180
-rw-r--r--drivers/iio/dac/stm32-dac-core.h51
-rw-r--r--drivers/iio/dac/stm32-dac.c334
5 files changed, 582 insertions, 0 deletions
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 08f2f9037409..df5abc46cd3f 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -284,6 +284,21 @@ config MCP4922
To compile this driver as a module, choose M here: the module
will be called mcp4922.
+config STM32_DAC
+ tristate "STMicroelectronics STM32 DAC"
+ depends on (ARCH_STM32 && OF) || COMPILE_TEST
+ depends on REGULATOR
+ select STM32_DAC_CORE
+ help
+ Say yes here to build support for STMicroelectronics STM32 Digital
+ to Analog Converter (DAC).
+
+ This driver can also be built as a module. If so, the module
+ will be called stm32-dac.
+
+config STM32_DAC_CORE
+ tristate
+
config VF610_DAC
tristate "Vybrid vf610 DAC driver"
depends on OF
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 6e4d99557309..603587cc2f07 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -30,4 +30,6 @@ obj-$(CONFIG_MAX517) += max517.o
obj-$(CONFIG_MAX5821) += max5821.o
obj-$(CONFIG_MCP4725) += mcp4725.o
obj-$(CONFIG_MCP4922) += mcp4922.o
+obj-$(CONFIG_STM32_DAC_CORE) += stm32-dac-core.o
+obj-$(CONFIG_STM32_DAC) += stm32-dac.o
obj-$(CONFIG_VF610_DAC) += vf610_dac.o
diff --git a/drivers/iio/dac/stm32-dac-core.c b/drivers/iio/dac/stm32-dac-core.c
new file mode 100644
index 000000000000..75e48788c7ea
--- /dev/null
+++ b/drivers/iio/dac/stm32-dac-core.c
@@ -0,0 +1,180 @@
+/*
+ * This file is part of STM32 DAC driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
+ *
+ * License type: GPLv2
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#include "stm32-dac-core.h"
+
+/**
+ * struct stm32_dac_priv - stm32 DAC core private data
+ * @pclk: peripheral clock common for all DACs
+ * @rst: peripheral reset control
+ * @vref: regulator reference
+ * @common: Common data for all DAC instances
+ */
+struct stm32_dac_priv {
+ struct clk *pclk;
+ struct reset_control *rst;
+ struct regulator *vref;
+ struct stm32_dac_common common;
+};
+
+static struct stm32_dac_priv *to_stm32_dac_priv(struct stm32_dac_common *com)
+{
+ return container_of(com, struct stm32_dac_priv, common);
+}
+
+static const struct regmap_config stm32_dac_regmap_cfg = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = sizeof(u32),
+ .max_register = 0x3fc,
+};
+
+static int stm32_dac_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct stm32_dac_priv *priv;
+ struct regmap *regmap;
+ struct resource *res;
+ void __iomem *mmio;
+ int ret;
+
+ if (!dev->of_node)
+ return -ENODEV;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mmio = devm_ioremap_resource(dev, res);
+ if (IS_ERR(mmio))
+ return PTR_ERR(mmio);
+
+ regmap = devm_regmap_init_mmio(dev, mmio, &stm32_dac_regmap_cfg);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+ priv->common.regmap = regmap;
+
+ priv->vref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(priv->vref)) {
+ ret = PTR_ERR(priv->vref);
+ dev_err(dev, "vref get failed, %d\n", ret);
+ return ret;
+ }
+
+ ret = regulator_enable(priv->vref);
+ if (ret < 0) {
+ dev_err(dev, "vref enable failed\n");
+ return ret;
+ }
+
+ ret = regulator_get_voltage(priv->vref);
+ if (ret < 0) {
+ dev_err(dev, "vref get voltage failed, %d\n", ret);
+ goto err_vref;
+ }
+ priv->common.vref_mv = ret / 1000;
+ dev_dbg(dev, "vref+=%dmV\n", priv->common.vref_mv);
+
+ priv->pclk = devm_clk_get(dev, "pclk");
+ if (IS_ERR(priv->pclk)) {
+ ret = PTR_ERR(priv->pclk);
+ dev_err(dev, "pclk get failed\n");
+ goto err_vref;
+ }
+
+ ret = clk_prepare_enable(priv->pclk);
+ if (ret < 0) {
+ dev_err(dev, "pclk enable failed\n");
+ goto err_vref;
+ }
+
+ priv->rst = devm_reset_control_get(dev, NULL);
+ if (!IS_ERR(priv->rst)) {
+ reset_control_assert(priv->rst);
+ udelay(2);
+ reset_control_deassert(priv->rst);
+ }
+
+ /* When clock speed is higher than 80MHz, set HFSEL */
+ priv->common.hfsel = (clk_get_rate(priv->pclk) > 80000000UL);
+ ret = regmap_update_bits(regmap, STM32_DAC_CR, STM32H7_DAC_CR_HFSEL,
+ priv->common.hfsel ? STM32H7_DAC_CR_HFSEL : 0);
+ if (ret)
+ goto err_pclk;
+
+ platform_set_drvdata(pdev, &priv->common);
+
+ ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, dev);
+ if (ret < 0) {
+ dev_err(dev, "failed to populate DT children\n");
+ goto err_pclk;
+ }
+
+ return 0;
+
+err_pclk:
+ clk_disable_unprepare(priv->pclk);
+err_vref:
+ regulator_disable(priv->vref);
+
+ return ret;
+}
+
+static int stm32_dac_remove(struct platform_device *pdev)
+{
+ struct stm32_dac_common *common = platform_get_drvdata(pdev);
+ struct stm32_dac_priv *priv = to_stm32_dac_priv(common);
+
+ of_platform_depopulate(&pdev->dev);
+ clk_disable_unprepare(priv->pclk);
+ regulator_disable(priv->vref);
+
+ return 0;
+}
+
+static const struct of_device_id stm32_dac_of_match[] = {
+ { .compatible = "st,stm32h7-dac-core", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
+
+static struct platform_driver stm32_dac_driver = {
+ .probe = stm32_dac_probe,
+ .remove = stm32_dac_remove,
+ .driver = {
+ .name = "stm32-dac-core",
+ .of_match_table = stm32_dac_of_match,
+ },
+};
+module_platform_driver(stm32_dac_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 DAC core driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:stm32-dac-core");
diff --git a/drivers/iio/dac/stm32-dac-core.h b/drivers/iio/dac/stm32-dac-core.h
new file mode 100644
index 000000000000..daf09931857c
--- /dev/null
+++ b/drivers/iio/dac/stm32-dac-core.h
@@ -0,0 +1,51 @@
+/*
+ * This file is part of STM32 DAC driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
+ *
+ * License type: GPLv2
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __STM32_DAC_CORE_H
+#define __STM32_DAC_CORE_H
+
+#include <linux/regmap.h>
+
+/* STM32 DAC registers */
+#define STM32_DAC_CR 0x00
+#define STM32_DAC_DHR12R1 0x08
+#define STM32_DAC_DHR12R2 0x14
+#define STM32_DAC_DOR1 0x2C
+#define STM32_DAC_DOR2 0x30
+
+/* STM32_DAC_CR bit fields */
+#define STM32_DAC_CR_EN1 BIT(0)
+#define STM32H7_DAC_CR_HFSEL BIT(15)
+#define STM32_DAC_CR_EN2 BIT(16)
+
+/**
+ * struct stm32_dac_common - stm32 DAC driver common data (for all instances)
+ * @regmap: DAC registers shared via regmap
+ * @vref_mv: reference voltage (mv)
+ * @hfsel: high speed bus clock selected
+ */
+struct stm32_dac_common {
+ struct regmap *regmap;
+ int vref_mv;
+ bool hfsel;
+};
+
+#endif
diff --git a/drivers/iio/dac/stm32-dac.c b/drivers/iio/dac/stm32-dac.c
new file mode 100644
index 000000000000..50f8ec091058
--- /dev/null
+++ b/drivers/iio/dac/stm32-dac.c
@@ -0,0 +1,334 @@
+/*
+ * This file is part of STM32 DAC driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Authors: Amelie Delaunay <amelie.delaunay@st.com>
+ * Fabrice Gasnier <fabrice.gasnier@st.com>
+ *
+ * License type: GPLv2
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "stm32-dac-core.h"
+
+#define STM32_DAC_CHANNEL_1 1
+#define STM32_DAC_CHANNEL_2 2
+#define STM32_DAC_IS_CHAN_1(ch) ((ch) & STM32_DAC_CHANNEL_1)
+
+/**
+ * struct stm32_dac - private data of DAC driver
+ * @common: reference to DAC common data
+ */
+struct stm32_dac {
+ struct stm32_dac_common *common;
+};
+
+static int stm32_dac_is_enabled(struct iio_dev *indio_dev, int channel)
+{
+ struct stm32_dac *dac = iio_priv(indio_dev);
+ u32 en, val;
+ int ret;
+
+ ret = regmap_read(dac->common->regmap, STM32_DAC_CR, &val);
+ if (ret < 0)
+ return ret;
+ if (STM32_DAC_IS_CHAN_1(channel))
+ en = FIELD_GET(STM32_DAC_CR_EN1, val);
+ else
+ en = FIELD_GET(STM32_DAC_CR_EN2, val);
+
+ return !!en;
+}
+
+static int stm32_dac_set_enable_state(struct iio_dev *indio_dev, int ch,
+ bool enable)
+{
+ struct stm32_dac *dac = iio_priv(indio_dev);
+ u32 msk = STM32_DAC_IS_CHAN_1(ch) ? STM32_DAC_CR_EN1 : STM32_DAC_CR_EN2;
+ u32 en = enable ? msk : 0;
+ int ret;
+
+ ret = regmap_update_bits(dac->common->regmap, STM32_DAC_CR, msk, en);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "%s failed\n", en ?
+ "Enable" : "Disable");
+ return ret;
+ }
+
+ /*
+ * When HFSEL is set, it is not allowed to write the DHRx register
+ * during 8 clock cycles after the ENx bit is set. It is not allowed
+ * to make software/hardware trigger during this period either.
+ */
+ if (en && dac->common->hfsel)
+ udelay(1);
+
+ return 0;
+}
+
+static int stm32_dac_get_value(struct stm32_dac *dac, int channel, int *val)
+{
+ int ret;
+
+ if (STM32_DAC_IS_CHAN_1(channel))
+ ret = regmap_read(dac->common->regmap, STM32_DAC_DOR1, val);
+ else
+ ret = regmap_read(dac->common->regmap, STM32_DAC_DOR2, val);
+
+ return ret ? ret : IIO_VAL_INT;
+}
+
+static int stm32_dac_set_value(struct stm32_dac *dac, int channel, int val)
+{
+ int ret;
+
+ if (STM32_DAC_IS_CHAN_1(channel))
+ ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R1, val);
+ else
+ ret = regmap_write(dac->common->regmap, STM32_DAC_DHR12R2, val);
+
+ return ret;
+}
+
+static int stm32_dac_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct stm32_dac *dac = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return stm32_dac_get_value(dac, chan->channel, val);
+ case IIO_CHAN_INFO_SCALE:
+ *val = dac->common->vref_mv;
+ *val2 = chan->scan_type.realbits;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int stm32_dac_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct stm32_dac *dac = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return stm32_dac_set_value(dac, chan->channel, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int stm32_dac_debugfs_reg_access(struct iio_dev *indio_dev,
+ unsigned reg, unsigned writeval,
+ unsigned *readval)
+{
+ struct stm32_dac *dac = iio_priv(indio_dev);
+
+ if (!readval)
+ return regmap_write(dac->common->regmap, reg, writeval);
+ else
+ return regmap_read(dac->common->regmap, reg, readval);
+}
+
+static const struct iio_info stm32_dac_iio_info = {
+ .read_raw = stm32_dac_read_raw,
+ .write_raw = stm32_dac_write_raw,
+ .debugfs_reg_access = stm32_dac_debugfs_reg_access,
+ .driver_module = THIS_MODULE,
+};
+
+static const char * const stm32_dac_powerdown_modes[] = {
+ "three_state",
+};
+
+static int stm32_dac_get_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ return 0;
+}
+
+static int stm32_dac_set_powerdown_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ unsigned int type)
+{
+ return 0;
+}
+
+static ssize_t stm32_dac_read_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ char *buf)
+{
+ int ret = stm32_dac_is_enabled(indio_dev, chan->channel);
+
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", ret ? 0 : 1);
+}
+
+static ssize_t stm32_dac_write_powerdown(struct iio_dev *indio_dev,
+ uintptr_t private,
+ const struct iio_chan_spec *chan,
+ const char *buf, size_t len)
+{
+ bool powerdown;
+ int ret;
+
+ ret = strtobool(buf, &powerdown);
+ if (ret)
+ return ret;
+
+ ret = stm32_dac_set_enable_state(indio_dev, chan->channel, !powerdown);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static const struct iio_enum stm32_dac_powerdown_mode_en = {
+ .items = stm32_dac_powerdown_modes,
+ .num_items = ARRAY_SIZE(stm32_dac_powerdown_modes),
+ .get = stm32_dac_get_powerdown_mode,
+ .set = stm32_dac_set_powerdown_mode,
+};
+
+static const struct iio_chan_spec_ext_info stm32_dac_ext_info[] = {
+ {
+ .name = "powerdown",
+ .read = stm32_dac_read_powerdown,
+ .write = stm32_dac_write_powerdown,
+ .shared = IIO_SEPARATE,
+ },
+ IIO_ENUM("powerdown_mode", IIO_SEPARATE, &stm32_dac_powerdown_mode_en),
+ IIO_ENUM_AVAILABLE("powerdown_mode", &stm32_dac_powerdown_mode_en),
+ {},
+};
+
+#define STM32_DAC_CHANNEL(chan, name) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = chan, \
+ .info_mask_separate = \
+ BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ /* scan_index is always 0 as num_channels is 1 */ \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 12, \
+ .storagebits = 16, \
+ }, \
+ .datasheet_name = name, \
+ .ext_info = stm32_dac_ext_info \
+}
+
+static const struct iio_chan_spec stm32_dac_channels[] = {
+ STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_1, "out1"),
+ STM32_DAC_CHANNEL(STM32_DAC_CHANNEL_2, "out2"),
+};
+
+static int stm32_dac_chan_of_init(struct iio_dev *indio_dev)
+{
+ struct device_node *np = indio_dev->dev.of_node;
+ unsigned int i;
+ u32 channel;
+ int ret;
+
+ ret = of_property_read_u32(np, "reg", &channel);
+ if (ret) {
+ dev_err(&indio_dev->dev, "Failed to read reg property\n");
+ return ret;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(stm32_dac_channels); i++) {
+ if (stm32_dac_channels[i].channel == channel)
+ break;
+ }
+ if (i >= ARRAY_SIZE(stm32_dac_channels)) {
+ dev_err(&indio_dev->dev, "Invalid st,dac-channel\n");
+ return -EINVAL;
+ }
+
+ indio_dev->channels = &stm32_dac_channels[i];
+ /*
+ * Expose only one channel here, as they can be used independently,
+ * with separate trigger. Then separate IIO devices are instantiated
+ * to manage this.
+ */
+ indio_dev->num_channels = 1;
+
+ return 0;
+};
+
+static int stm32_dac_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct iio_dev *indio_dev;
+ struct stm32_dac *dac;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ 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);
+ dac->common = dev_get_drvdata(pdev->dev.parent);
+ 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 = &stm32_dac_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = stm32_dac_chan_of_init(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static const struct of_device_id stm32_dac_of_match[] = {
+ { .compatible = "st,stm32-dac", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm32_dac_of_match);
+
+static struct platform_driver stm32_dac_driver = {
+ .probe = stm32_dac_probe,
+ .driver = {
+ .name = "stm32-dac",
+ .of_match_table = stm32_dac_of_match,
+ },
+};
+module_platform_driver(stm32_dac_driver);
+
+MODULE_ALIAS("platform:stm32-dac");
+MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 DAC driver");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-25 06:02:52 +0000