diff options
Diffstat (limited to 'drivers/iio/dac')
-rw-r--r-- | drivers/iio/dac/Kconfig | 15 | ||||
-rw-r--r-- | drivers/iio/dac/Makefile | 2 | ||||
-rw-r--r-- | drivers/iio/dac/stm32-dac-core.c | 180 | ||||
-rw-r--r-- | drivers/iio/dac/stm32-dac-core.h | 51 | ||||
-rw-r--r-- | drivers/iio/dac/stm32-dac.c | 334 |
5 files changed, 582 insertions, 0 deletions
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig index 08f2f90..df5abc4 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 6e4d995..603587c 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 0000000..75e4878 --- /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 0000000..daf0993 --- /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 0000000..50f8ec0 --- /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"); |