[alsa-devel] Applied "IIO: ADC: add STM32 DFSDM sigma delta ADC support" to the asoc tree
Mark Brown
broonie at kernel.org
Wed Jan 10 12:13:02 CET 2018
The patch
IIO: ADC: add STM32 DFSDM sigma delta ADC support
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
>From e2e6771c646251657fafb2a78db566d5c2c70635 Mon Sep 17 00:00:00 2001
From: Arnaud Pouliquen <arnaud.pouliquen at st.com>
Date: Wed, 10 Jan 2018 11:13:11 +0100
Subject: [PATCH] IIO: ADC: add STM32 DFSDM sigma delta ADC support
Add DFSDM driver to handle sigma delta ADC.
Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen at st.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron at huawei.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
drivers/iio/adc/Kconfig | 13 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/stm32-dfsdm-adc.c | 728 ++++++++++++++++++++++++++++++++++++++
3 files changed, 742 insertions(+)
create mode 100644 drivers/iio/adc/stm32-dfsdm-adc.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 776192e68ad5..39e3b345a6c8 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -680,6 +680,19 @@ config STM32_DFSDM_CORE
This driver can also be built as a module. If so, the module
will be called stm32-dfsdm-core.
+config STM32_DFSDM_ADC
+ tristate "STMicroelectronics STM32 dfsdm adc"
+ depends on (ARCH_STM32 && OF) || COMPILE_TEST
+ select STM32_DFSDM_CORE
+ select REGMAP_MMIO
+ select IIO_BUFFER_HW_CONSUMER
+ help
+ Select this option to support ADCSigma delta modulator for
+ STMicroelectronics STM32 digital filter for sigma delta converter.
+
+ This driver can also be built as a module. If so, the module
+ will be called stm32-dfsdm-adc.
+
config STX104
tristate "Apex Embedded Systems STX104 driver"
depends on PC104 && X86 && ISA_BUS_API
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 8dda348f1920..28a9423997f3 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_SUN4I_GPADC) += sun4i-gpadc-iio.o
obj-$(CONFIG_STM32_ADC_CORE) += stm32-adc-core.o
obj-$(CONFIG_STM32_ADC) += stm32-adc.o
obj-$(CONFIG_STM32_DFSDM_CORE) += stm32-dfsdm-core.o
+obj-$(CONFIG_STM32_DFSDM_ADC) += stm32-dfsdm-adc.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
obj-$(CONFIG_TI_ADC0832) += ti-adc0832.o
obj-$(CONFIG_TI_ADC084S021) += ti-adc084s021.o
diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
new file mode 100644
index 000000000000..68b5920e92cb
--- /dev/null
+++ b/drivers/iio/adc/stm32-dfsdm-adc.c
@@ -0,0 +1,728 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file is the ADC part of the STM32 DFSDM driver
+ *
+ * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
+ * Author: Arnaud Pouliquen <arnaud.pouliquen at st.com>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/hw-consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "stm32-dfsdm.h"
+
+/* Conversion timeout */
+#define DFSDM_TIMEOUT_US 100000
+#define DFSDM_TIMEOUT (msecs_to_jiffies(DFSDM_TIMEOUT_US / 1000))
+
+/* Oversampling attribute default */
+#define DFSDM_DEFAULT_OVERSAMPLING 100
+
+/* Oversampling max values */
+#define DFSDM_MAX_INT_OVERSAMPLING 256
+#define DFSDM_MAX_FL_OVERSAMPLING 1024
+
+/* Max sample resolutions */
+#define DFSDM_MAX_RES BIT(31)
+#define DFSDM_DATA_RES BIT(23)
+
+enum sd_converter_type {
+ DFSDM_AUDIO,
+ DFSDM_IIO,
+};
+
+struct stm32_dfsdm_dev_data {
+ int type;
+ int (*init)(struct iio_dev *indio_dev);
+ unsigned int num_channels;
+ const struct regmap_config *regmap_cfg;
+};
+
+struct stm32_dfsdm_adc {
+ struct stm32_dfsdm *dfsdm;
+ const struct stm32_dfsdm_dev_data *dev_data;
+ unsigned int fl_id;
+ unsigned int ch_id;
+
+ /* ADC specific */
+ unsigned int oversamp;
+ struct iio_hw_consumer *hwc;
+ struct completion completion;
+ u32 *buffer;
+
+};
+
+struct stm32_dfsdm_str2field {
+ const char *name;
+ unsigned int val;
+};
+
+/* DFSDM channel serial interface type */
+static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_type[] = {
+ { "SPI_R", 0 }, /* SPI with data on rising edge */
+ { "SPI_F", 1 }, /* SPI with data on falling edge */
+ { "MANCH_R", 2 }, /* Manchester codec, rising edge = logic 0 */
+ { "MANCH_F", 3 }, /* Manchester codec, falling edge = logic 1 */
+ {},
+};
+
+/* DFSDM channel clock source */
+static const struct stm32_dfsdm_str2field stm32_dfsdm_chan_src[] = {
+ /* External SPI clock (CLKIN x) */
+ { "CLKIN", DFSDM_CHANNEL_SPI_CLOCK_EXTERNAL },
+ /* Internal SPI clock (CLKOUT) */
+ { "CLKOUT", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL },
+ /* Internal SPI clock divided by 2 (falling edge) */
+ { "CLKOUT_F", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_FALLING },
+ /* Internal SPI clock divided by 2 (falling edge) */
+ { "CLKOUT_R", DFSDM_CHANNEL_SPI_CLOCK_INTERNAL_DIV2_RISING },
+ {},
+};
+
+static int stm32_dfsdm_str2val(const char *str,
+ const struct stm32_dfsdm_str2field *list)
+{
+ const struct stm32_dfsdm_str2field *p = list;
+
+ for (p = list; p && p->name; p++)
+ if (!strcmp(p->name, str))
+ return p->val;
+
+ return -EINVAL;
+}
+
+static int stm32_dfsdm_set_osrs(struct stm32_dfsdm_filter *fl,
+ unsigned int fast, unsigned int oversamp)
+{
+ unsigned int i, d, fosr, iosr;
+ u64 res;
+ s64 delta;
+ unsigned int m = 1; /* multiplication factor */
+ unsigned int p = fl->ford; /* filter order (ford) */
+
+ pr_debug("%s: Requested oversampling: %d\n", __func__, oversamp);
+ /*
+ * This function tries to compute filter oversampling and integrator
+ * oversampling, base on oversampling ratio requested by user.
+ *
+ * Decimation d depends on the filter order and the oversampling ratios.
+ * ford: filter order
+ * fosr: filter over sampling ratio
+ * iosr: integrator over sampling ratio
+ */
+ if (fl->ford == DFSDM_FASTSINC_ORDER) {
+ m = 2;
+ p = 2;
+ }
+
+ /*
+ * Look for filter and integrator oversampling ratios which allows
+ * to reach 24 bits data output resolution.
+ * Leave as soon as if exact resolution if reached.
+ * Otherwise the higher resolution below 32 bits is kept.
+ */
+ for (fosr = 1; fosr <= DFSDM_MAX_FL_OVERSAMPLING; fosr++) {
+ for (iosr = 1; iosr <= DFSDM_MAX_INT_OVERSAMPLING; iosr++) {
+ if (fast)
+ d = fosr * iosr;
+ else if (fl->ford == DFSDM_FASTSINC_ORDER)
+ d = fosr * (iosr + 3) + 2;
+ else
+ d = fosr * (iosr - 1 + p) + p;
+
+ if (d > oversamp)
+ break;
+ else if (d != oversamp)
+ continue;
+ /*
+ * Check resolution (limited to signed 32 bits)
+ * res <= 2^31
+ * Sincx filters:
+ * res = m * fosr^p x iosr (with m=1, p=ford)
+ * FastSinc filter
+ * res = m * fosr^p x iosr (with m=2, p=2)
+ */
+ res = fosr;
+ for (i = p - 1; i > 0; i--) {
+ res = res * (u64)fosr;
+ if (res > DFSDM_MAX_RES)
+ break;
+ }
+ if (res > DFSDM_MAX_RES)
+ continue;
+ res = res * (u64)m * (u64)iosr;
+ if (res > DFSDM_MAX_RES)
+ continue;
+
+ delta = res - DFSDM_DATA_RES;
+
+ if (res >= fl->res) {
+ fl->res = res;
+ fl->fosr = fosr;
+ fl->iosr = iosr;
+ fl->fast = fast;
+ pr_debug("%s: fosr = %d, iosr = %d\n",
+ __func__, fl->fosr, fl->iosr);
+ }
+
+ if (!delta)
+ return 0;
+ }
+ }
+
+ if (!fl->fosr)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int stm32_dfsdm_start_channel(struct stm32_dfsdm *dfsdm,
+ unsigned int ch_id)
+{
+ return regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
+ DFSDM_CHCFGR1_CHEN_MASK,
+ DFSDM_CHCFGR1_CHEN(1));
+}
+
+static void stm32_dfsdm_stop_channel(struct stm32_dfsdm *dfsdm,
+ unsigned int ch_id)
+{
+ regmap_update_bits(dfsdm->regmap, DFSDM_CHCFGR1(ch_id),
+ DFSDM_CHCFGR1_CHEN_MASK, DFSDM_CHCFGR1_CHEN(0));
+}
+
+static int stm32_dfsdm_chan_configure(struct stm32_dfsdm *dfsdm,
+ struct stm32_dfsdm_channel *ch)
+{
+ unsigned int id = ch->id;
+ struct regmap *regmap = dfsdm->regmap;
+ int ret;
+
+ ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+ DFSDM_CHCFGR1_SITP_MASK,
+ DFSDM_CHCFGR1_SITP(ch->type));
+ if (ret < 0)
+ return ret;
+ ret = regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+ DFSDM_CHCFGR1_SPICKSEL_MASK,
+ DFSDM_CHCFGR1_SPICKSEL(ch->src));
+ if (ret < 0)
+ return ret;
+ return regmap_update_bits(regmap, DFSDM_CHCFGR1(id),
+ DFSDM_CHCFGR1_CHINSEL_MASK,
+ DFSDM_CHCFGR1_CHINSEL(ch->alt_si));
+}
+
+static int stm32_dfsdm_start_filter(struct stm32_dfsdm *dfsdm,
+ unsigned int fl_id)
+{
+ int ret;
+
+ /* Enable filter */
+ ret = regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(1));
+ if (ret < 0)
+ return ret;
+
+ /* Start conversion */
+ return regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_RSWSTART_MASK,
+ DFSDM_CR1_RSWSTART(1));
+}
+
+void stm32_dfsdm_stop_filter(struct stm32_dfsdm *dfsdm, unsigned int fl_id)
+{
+ /* Disable conversion */
+ regmap_update_bits(dfsdm->regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_DFEN_MASK, DFSDM_CR1_DFEN(0));
+}
+
+static int stm32_dfsdm_filter_configure(struct stm32_dfsdm *dfsdm,
+ unsigned int fl_id, unsigned int ch_id)
+{
+ struct regmap *regmap = dfsdm->regmap;
+ struct stm32_dfsdm_filter *fl = &dfsdm->fl_list[fl_id];
+ int ret;
+
+ /* Average integrator oversampling */
+ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_IOSR_MASK,
+ DFSDM_FCR_IOSR(fl->iosr - 1));
+ if (ret)
+ return ret;
+
+ /* Filter order and Oversampling */
+ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FOSR_MASK,
+ DFSDM_FCR_FOSR(fl->fosr - 1));
+ if (ret)
+ return ret;
+
+ ret = regmap_update_bits(regmap, DFSDM_FCR(fl_id), DFSDM_FCR_FORD_MASK,
+ DFSDM_FCR_FORD(fl->ford));
+ if (ret)
+ return ret;
+
+ /* No scan mode supported for the moment */
+ ret = regmap_update_bits(regmap, DFSDM_CR1(fl_id), DFSDM_CR1_RCH_MASK,
+ DFSDM_CR1_RCH(ch_id));
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(regmap, DFSDM_CR1(fl_id),
+ DFSDM_CR1_RSYNC_MASK,
+ DFSDM_CR1_RSYNC(fl->sync_mode));
+}
+
+int stm32_dfsdm_channel_parse_of(struct stm32_dfsdm *dfsdm,
+ struct iio_dev *indio_dev,
+ struct iio_chan_spec *ch)
+{
+ struct stm32_dfsdm_channel *df_ch;
+ const char *of_str;
+ int chan_idx = ch->scan_index;
+ int ret, val;
+
+ ret = of_property_read_u32_index(indio_dev->dev.of_node,
+ "st,adc-channels", chan_idx,
+ &ch->channel);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ " Error parsing 'st,adc-channels' for idx %d\n",
+ chan_idx);
+ return ret;
+ }
+ if (ch->channel >= dfsdm->num_chs) {
+ dev_err(&indio_dev->dev,
+ " Error bad channel number %d (max = %d)\n",
+ ch->channel, dfsdm->num_chs);
+ return -EINVAL;
+ }
+
+ ret = of_property_read_string_index(indio_dev->dev.of_node,
+ "st,adc-channel-names", chan_idx,
+ &ch->datasheet_name);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ " Error parsing 'st,adc-channel-names' for idx %d\n",
+ chan_idx);
+ return ret;
+ }
+
+ df_ch = &dfsdm->ch_list[ch->channel];
+ df_ch->id = ch->channel;
+
+ ret = of_property_read_string_index(indio_dev->dev.of_node,
+ "st,adc-channel-types", chan_idx,
+ &of_str);
+ if (!ret) {
+ val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_type);
+ if (val < 0)
+ return val;
+ } else {
+ val = 0;
+ }
+ df_ch->type = val;
+
+ ret = of_property_read_string_index(indio_dev->dev.of_node,
+ "st,adc-channel-clk-src", chan_idx,
+ &of_str);
+ if (!ret) {
+ val = stm32_dfsdm_str2val(of_str, stm32_dfsdm_chan_src);
+ if (val < 0)
+ return val;
+ } else {
+ val = 0;
+ }
+ df_ch->src = val;
+
+ ret = of_property_read_u32_index(indio_dev->dev.of_node,
+ "st,adc-alt-channel", chan_idx,
+ &df_ch->alt_si);
+ if (ret < 0)
+ df_ch->alt_si = 0;
+
+ return 0;
+}
+
+static int stm32_dfsdm_start_conv(struct stm32_dfsdm_adc *adc, bool dma)
+{
+ struct regmap *regmap = adc->dfsdm->regmap;
+ int ret;
+
+ ret = stm32_dfsdm_start_channel(adc->dfsdm, adc->ch_id);
+ if (ret < 0)
+ return ret;
+
+ ret = stm32_dfsdm_filter_configure(adc->dfsdm, adc->fl_id,
+ adc->ch_id);
+ if (ret < 0)
+ goto stop_channels;
+
+ ret = stm32_dfsdm_start_filter(adc->dfsdm, adc->fl_id);
+ if (ret < 0)
+ goto stop_channels;
+
+ return 0;
+
+stop_channels:
+ regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+ DFSDM_CR1_RDMAEN_MASK, 0);
+
+ regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+ DFSDM_CR1_RCONT_MASK, 0);
+ stm32_dfsdm_stop_channel(adc->dfsdm, adc->fl_id);
+
+ return ret;
+}
+
+static void stm32_dfsdm_stop_conv(struct stm32_dfsdm_adc *adc)
+{
+ struct regmap *regmap = adc->dfsdm->regmap;
+
+ stm32_dfsdm_stop_filter(adc->dfsdm, adc->fl_id);
+
+ /* Clean conversion options */
+ regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+ DFSDM_CR1_RDMAEN_MASK, 0);
+
+ regmap_update_bits(regmap, DFSDM_CR1(adc->fl_id),
+ DFSDM_CR1_RCONT_MASK, 0);
+
+ stm32_dfsdm_stop_channel(adc->dfsdm, adc->ch_id);
+}
+
+static int stm32_dfsdm_single_conv(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, int *res)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ long timeout;
+ int ret;
+
+ reinit_completion(&adc->completion);
+
+ adc->buffer = res;
+
+ ret = stm32_dfsdm_start_dfsdm(adc->dfsdm);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+ DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(1));
+ if (ret < 0)
+ goto stop_dfsdm;
+
+ ret = stm32_dfsdm_start_conv(adc, false);
+ if (ret < 0) {
+ regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+ DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
+ goto stop_dfsdm;
+ }
+
+ timeout = wait_for_completion_interruptible_timeout(&adc->completion,
+ DFSDM_TIMEOUT);
+
+ /* Mask IRQ for regular conversion achievement*/
+ regmap_update_bits(adc->dfsdm->regmap, DFSDM_CR2(adc->fl_id),
+ DFSDM_CR2_REOCIE_MASK, DFSDM_CR2_REOCIE(0));
+
+ if (timeout == 0)
+ ret = -ETIMEDOUT;
+ else if (timeout < 0)
+ ret = timeout;
+ else
+ ret = IIO_VAL_INT;
+
+ stm32_dfsdm_stop_conv(adc);
+
+stop_dfsdm:
+ stm32_dfsdm_stop_dfsdm(adc->dfsdm);
+
+ return ret;
+}
+
+static int stm32_dfsdm_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ struct stm32_dfsdm_filter *fl = &adc->dfsdm->fl_list[adc->fl_id];
+ int ret = -EINVAL;
+
+ if (mask == IIO_CHAN_INFO_OVERSAMPLING_RATIO) {
+ ret = stm32_dfsdm_set_osrs(fl, 0, val);
+ if (!ret)
+ adc->oversamp = val;
+ }
+
+ return ret;
+}
+
+static int stm32_dfsdm_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_hw_consumer_enable(adc->hwc);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ "%s: IIO enable failed (channel %d)\n",
+ __func__, chan->channel);
+ return ret;
+ }
+ ret = stm32_dfsdm_single_conv(indio_dev, chan, val);
+ iio_hw_consumer_disable(adc->hwc);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev,
+ "%s: Conversion failed (channel %d)\n",
+ __func__, chan->channel);
+ return ret;
+ }
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ *val = adc->oversamp;
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info stm32_dfsdm_info_adc = {
+ .read_raw = stm32_dfsdm_read_raw,
+ .write_raw = stm32_dfsdm_write_raw,
+};
+
+static irqreturn_t stm32_dfsdm_irq(int irq, void *arg)
+{
+ struct stm32_dfsdm_adc *adc = arg;
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+ struct regmap *regmap = adc->dfsdm->regmap;
+ unsigned int status, int_en;
+
+ regmap_read(regmap, DFSDM_ISR(adc->fl_id), &status);
+ regmap_read(regmap, DFSDM_CR2(adc->fl_id), &int_en);
+
+ if (status & DFSDM_ISR_REOCF_MASK) {
+ /* Read the data register clean the IRQ status */
+ regmap_read(regmap, DFSDM_RDATAR(adc->fl_id), adc->buffer);
+ complete(&adc->completion);
+ }
+
+ if (status & DFSDM_ISR_ROVRF_MASK) {
+ if (int_en & DFSDM_CR2_ROVRIE_MASK)
+ dev_warn(&indio_dev->dev, "Overrun detected\n");
+ regmap_update_bits(regmap, DFSDM_ICR(adc->fl_id),
+ DFSDM_ICR_CLRROVRF_MASK,
+ DFSDM_ICR_CLRROVRF_MASK);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int stm32_dfsdm_adc_chan_init_one(struct iio_dev *indio_dev,
+ struct iio_chan_spec *ch)
+{
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ int ret;
+
+ ret = stm32_dfsdm_channel_parse_of(adc->dfsdm, indio_dev, ch);
+ if (ret < 0)
+ return ret;
+
+ ch->type = IIO_VOLTAGE;
+ ch->indexed = 1;
+
+ /*
+ * IIO_CHAN_INFO_RAW: used to compute regular conversion
+ * IIO_CHAN_INFO_OVERSAMPLING_RATIO: used to set oversampling
+ */
+ ch->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+ ch->info_mask_shared_by_all = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO);
+
+ ch->scan_type.sign = 'u';
+ ch->scan_type.realbits = 24;
+ ch->scan_type.storagebits = 32;
+ adc->ch_id = ch->channel;
+
+ return stm32_dfsdm_chan_configure(adc->dfsdm,
+ &adc->dfsdm->ch_list[ch->channel]);
+}
+
+static int stm32_dfsdm_adc_init(struct iio_dev *indio_dev)
+{
+ struct iio_chan_spec *ch;
+ struct stm32_dfsdm_adc *adc = iio_priv(indio_dev);
+ int num_ch;
+ int ret, chan_idx;
+
+ adc->oversamp = DFSDM_DEFAULT_OVERSAMPLING;
+ ret = stm32_dfsdm_set_osrs(&adc->dfsdm->fl_list[adc->fl_id], 0,
+ adc->oversamp);
+ if (ret < 0)
+ return ret;
+
+ num_ch = of_property_count_u32_elems(indio_dev->dev.of_node,
+ "st,adc-channels");
+ if (num_ch < 0 || num_ch > adc->dfsdm->num_chs) {
+ dev_err(&indio_dev->dev, "Bad st,adc-channels\n");
+ return num_ch < 0 ? num_ch : -EINVAL;
+ }
+
+ /* Bind to SD modulator IIO device */
+ adc->hwc = devm_iio_hw_consumer_alloc(&indio_dev->dev);
+ if (IS_ERR(adc->hwc))
+ return -EPROBE_DEFER;
+
+ ch = devm_kcalloc(&indio_dev->dev, num_ch, sizeof(*ch),
+ GFP_KERNEL);
+ if (!ch)
+ return -ENOMEM;
+
+ for (chan_idx = 0; chan_idx < num_ch; chan_idx++) {
+ ch->scan_index = chan_idx;
+ ret = stm32_dfsdm_adc_chan_init_one(indio_dev, ch);
+ if (ret < 0) {
+ dev_err(&indio_dev->dev, "Channels init failed\n");
+ return ret;
+ }
+ }
+
+ indio_dev->num_channels = num_ch;
+ indio_dev->channels = ch;
+
+ init_completion(&adc->completion);
+
+ return 0;
+}
+
+static const struct stm32_dfsdm_dev_data stm32h7_dfsdm_adc_data = {
+ .type = DFSDM_IIO,
+ .init = stm32_dfsdm_adc_init,
+};
+
+static const struct of_device_id stm32_dfsdm_adc_match[] = {
+ {
+ .compatible = "st,stm32-dfsdm-adc",
+ .data = &stm32h7_dfsdm_adc_data,
+ },
+ {}
+};
+
+static int stm32_dfsdm_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct stm32_dfsdm_adc *adc;
+ struct device_node *np = dev->of_node;
+ const struct stm32_dfsdm_dev_data *dev_data;
+ struct iio_dev *iio;
+ const struct of_device_id *of_id;
+ char *name;
+ int ret, irq, val;
+
+ of_id = of_match_node(stm32_dfsdm_adc_match, np);
+ if (!of_id->data) {
+ dev_err(&pdev->dev, "Data associated to device is missing\n");
+ return -EINVAL;
+ }
+
+ dev_data = (const struct stm32_dfsdm_dev_data *)of_id->data;
+
+ iio = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (IS_ERR(iio)) {
+ dev_err(dev, "%s: Failed to allocate IIO\n", __func__);
+ return PTR_ERR(iio);
+ }
+
+ adc = iio_priv(iio);
+ if (IS_ERR(adc)) {
+ dev_err(dev, "%s: Failed to allocate ADC\n", __func__);
+ return PTR_ERR(adc);
+ }
+ adc->dfsdm = dev_get_drvdata(dev->parent);
+
+ iio->dev.parent = dev;
+ iio->dev.of_node = np;
+ iio->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+
+ platform_set_drvdata(pdev, adc);
+
+ ret = of_property_read_u32(dev->of_node, "reg", &adc->fl_id);
+ if (ret != 0) {
+ dev_err(dev, "Missing reg property\n");
+ return -EINVAL;
+ }
+
+ name = devm_kzalloc(dev, sizeof("dfsdm-adc0"), GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+ iio->info = &stm32_dfsdm_info_adc;
+ snprintf(name, sizeof("dfsdm-adc0"), "dfsdm-adc%d", adc->fl_id);
+ iio->name = name;
+
+ /*
+ * In a first step IRQs generated for channels are not treated.
+ * So IRQ associated to filter instance 0 is dedicated to the Filter 0.
+ */
+ irq = platform_get_irq(pdev, 0);
+ ret = devm_request_irq(dev, irq, stm32_dfsdm_irq,
+ 0, pdev->name, adc);
+ if (ret < 0) {
+ dev_err(dev, "Failed to request IRQ\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(dev->of_node, "st,filter-order", &val);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set filter order\n");
+ return ret;
+ }
+
+ adc->dfsdm->fl_list[adc->fl_id].ford = val;
+
+ ret = of_property_read_u32(dev->of_node, "st,filter0-sync", &val);
+ if (!ret)
+ adc->dfsdm->fl_list[adc->fl_id].sync_mode = val;
+
+ adc->dev_data = dev_data;
+ ret = dev_data->init(iio);
+ if (ret < 0)
+ return ret;
+
+ return iio_device_register(iio);
+}
+
+static int stm32_dfsdm_adc_remove(struct platform_device *pdev)
+{
+ struct stm32_dfsdm_adc *adc = platform_get_drvdata(pdev);
+ struct iio_dev *indio_dev = iio_priv_to_dev(adc);
+
+ iio_device_unregister(indio_dev);
+
+ return 0;
+}
+
+static struct platform_driver stm32_dfsdm_adc_driver = {
+ .driver = {
+ .name = "stm32-dfsdm-adc",
+ .of_match_table = stm32_dfsdm_adc_match,
+ },
+ .probe = stm32_dfsdm_adc_probe,
+ .remove = stm32_dfsdm_adc_remove,
+};
+module_platform_driver(stm32_dfsdm_adc_driver);
+
+MODULE_DESCRIPTION("STM32 sigma delta ADC");
+MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen at st.com>");
+MODULE_LICENSE("GPL v2");
--
2.15.1
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