- Basic support for iio backend.
- Supports IIO_CHAN_INFO_SAMP_FREQ R/W.
- Only hardware mode is available, and that IIO_CHAN_INFO_RAW is not
supported if iio-backend mode is selected.
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
---
drivers/iio/adc/Kconfig | 2 +
drivers/iio/adc/ad7606.c | 154 ++++++++++++++++++++++++++++++++++---------
drivers/iio/adc/ad7606.h | 15 +++++
drivers/iio/adc/ad7606_par.c | 92 +++++++++++++++++++++++++-
4 files changed, 231 insertions(+), 32 deletions(-)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 91873f60322d..a57b5f0bc070 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -224,9 +224,11 @@ config AD7606_IFACE_PARALLEL
tristate "Analog Devices AD7606 ADC driver with parallel interface support"
depends on HAS_IOPORT
select AD7606
+ select IIO_BACKEND
help
Say yes here to build parallel interface support for Analog Devices:
ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
+ It also support iio_backended devices for AD7606B.
To compile this driver as a module, choose M here: the
module will be called ad7606_par.
diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 34d377e9ac79..7871552ce5ac 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -21,6 +21,7 @@
#include <linux/units.h>
#include <linux/util_macros.h>
+#include <linux/iio/backend.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -191,6 +192,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606_4_info, IIO_AD7606);
const struct ad7606_chip_info ad7606b_info = {
.channels = ad7606_channels_16bit,
+ .max_samplerate = 800 * KILO,
.name = "ad7606b",
.num_adc_channels = 8,
.num_channels = 9,
@@ -490,6 +492,17 @@ static int ad7606_pwm_set_low(struct ad7606_state *st)
return ret;
}
+static int ad7606_pwm_set_swing(struct ad7606_state *st)
+{
+ struct pwm_state cnvst_pwm_state;
+
+ pwm_get_state(st->cnvst_pwm, &cnvst_pwm_state);
+ cnvst_pwm_state.enabled = true;
+ cnvst_pwm_state.duty_cycle = cnvst_pwm_state.period / 2;
+
+ return pwm_apply_might_sleep(st->cnvst_pwm, &cnvst_pwm_state);
+}
+
static bool ad7606_pwm_is_swinging(struct ad7606_state *st)
{
struct pwm_state cnvst_pwm_state;
@@ -576,11 +589,22 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch,
if (ret < 0)
return ret;
}
- ret = wait_for_completion_timeout(&st->completion,
- msecs_to_jiffies(1000));
- if (!ret) {
- ret = -ETIMEDOUT;
- goto error_ret;
+
+ /*
+ * If no backend, wait for the interruption on busy pin, otherwise just add
+ * a delay to leave time for the data to be available. For now, the latter
+ * will not happen because IIO_CHAN_INFO_RAW is not supported for the backend.
+ * TODO: Add support for reading a single value when the backend is used.
+ */
+ if (!st->back) {
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(1000));
+ if (!ret) {
+ ret = -ETIMEDOUT;
+ goto error_ret;
+ }
+ } else {
+ fsleep(1);
}
ret = ad7606_read_samples(st);
@@ -620,6 +644,7 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
int ret, ch = 0;
struct ad7606_state *st = iio_priv(indio_dev);
struct ad7606_chan_scale *cs;
+ struct pwm_state cnvst_pwm_state;
switch (m) {
case IIO_CHAN_INFO_RAW:
@@ -640,6 +665,14 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = st->oversampling;
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ /*
+ * TODO: return the real frequency intead of the requested one once
+ * pwm_get_state_hw comes upstream.
+ */
+ pwm_get_state(st->cnvst_pwm, &cnvst_pwm_state);
+ *val = DIV_ROUND_CLOSEST_ULL(NSEC_PER_SEC, cnvst_pwm_state.period);
+ return IIO_VAL_INT;
}
return -EINVAL;
}
@@ -732,6 +765,10 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
return ret;
return 0;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (val < 0 && val2 != 0)
+ return -EINVAL;
+ return ad7606_set_sampling_freq(st, val);
default:
return -EINVAL;
}
@@ -914,14 +951,50 @@ static int ad7606_read_avail(struct iio_dev *indio_dev,
return -EINVAL;
}
+static int ad7606_backend_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct ad7606_state *st = iio_priv(indio_dev);
+
+ return ad7606_pwm_set_swing(st);
+}
+
+static int ad7606_backend_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct ad7606_state *st = iio_priv(indio_dev);
+
+ return ad7606_pwm_set_low(st);
+}
+
+static int ad7606_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct ad7606_state *st = iio_priv(indio_dev);
+
+ /*
+ * The update scan mode is only for iio backend compatible drivers.
+ * If the specific update_scan_mode is not defined in the bus ops,
+ * just do nothing and return 0.
+ */
+ if (!st->bops->update_scan_mode)
+ return 0;
+
+ return st->bops->update_scan_mode(indio_dev, scan_mask);
+}
+
static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
.postenable = &ad7606_buffer_postenable,
.predisable = &ad7606_buffer_predisable,
};
+static const struct iio_buffer_setup_ops ad7606_backend_buffer_ops = {
+ .postenable = &ad7606_backend_buffer_postenable,
+ .predisable = &ad7606_backend_buffer_predisable,
+};
+
static const struct iio_info ad7606_info_no_os_or_range = {
.read_raw = &ad7606_read_raw,
.validate_trigger = &ad7606_validate_trigger,
+ .update_scan_mode = &ad7606_update_scan_mode,
};
static const struct iio_info ad7606_info_os_and_range = {
@@ -929,6 +1002,7 @@ static const struct iio_info ad7606_info_os_and_range = {
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_os_and_range,
.validate_trigger = &ad7606_validate_trigger,
+ .update_scan_mode = &ad7606_update_scan_mode,
};
static const struct iio_info ad7606_info_sw_mode = {
@@ -937,6 +1011,7 @@ static const struct iio_info ad7606_info_sw_mode = {
.read_avail = &ad7606_read_avail,
.debugfs_reg_access = &ad7606_reg_access,
.validate_trigger = &ad7606_validate_trigger,
+ .update_scan_mode = &ad7606_update_scan_mode,
};
static const struct iio_info ad7606_info_os = {
@@ -944,6 +1019,7 @@ static const struct iio_info ad7606_info_os = {
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_os,
.validate_trigger = &ad7606_validate_trigger,
+ .update_scan_mode = &ad7606_update_scan_mode,
};
static const struct iio_info ad7606_info_range = {
@@ -951,6 +1027,7 @@ static const struct iio_info ad7606_info_range = {
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_range,
.validate_trigger = &ad7606_validate_trigger,
+ .update_scan_mode = &ad7606_update_scan_mode,
};
static const struct iio_trigger_ops ad7606_trigger_ops = {
@@ -1070,8 +1147,6 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
- init_completion(&st->completion);
-
ret = ad7606_reset(st);
if (ret)
dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
@@ -1118,34 +1193,51 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
if (ret)
return ret;
}
- st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
- indio_dev->name,
- iio_device_id(indio_dev));
- if (!st->trig)
- return -ENOMEM;
- st->trig->ops = &ad7606_trigger_ops;
- iio_trigger_set_drvdata(st->trig, indio_dev);
- ret = devm_iio_trigger_register(dev, st->trig);
- if (ret)
- return ret;
+ if (st->bops->iio_backend_config) {
+ /*
+ * If there is a backend, the PWM should not overpass the maximum sampling
+ * frequency the chip supports.
+ */
+ ret = ad7606_set_sampling_freq(st,
+ chip_info->max_samplerate ? : 2 * KILO);
+ if (ret)
+ return ret;
+
+ ret = st->bops->iio_backend_config(dev, indio_dev);
+ if (ret)
+ return ret;
- indio_dev->trig = iio_trigger_get(st->trig);
+ indio_dev->setup_ops = &ad7606_backend_buffer_ops;
+ } else {
+ init_completion(&st->completion);
+ st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!st->trig)
+ return -ENOMEM;
+
+ st->trig->ops = &ad7606_trigger_ops;
+ iio_trigger_set_drvdata(st->trig, indio_dev);
+ ret = devm_iio_trigger_register(dev, st->trig);
+ if (ret)
+ return ret;
- ret = devm_request_threaded_irq(dev, irq,
- NULL,
- &ad7606_interrupt,
- IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
- chip_info->name, indio_dev);
- if (ret)
- return ret;
+ indio_dev->trig = iio_trigger_get(st->trig);
- ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
- &iio_pollfunc_store_time,
- &ad7606_trigger_handler,
- &ad7606_buffer_ops);
- if (ret)
- return ret;
+ ret = devm_request_threaded_irq(dev, irq, NULL, &ad7606_interrupt,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ chip_info->name, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ &iio_pollfunc_store_time,
+ &ad7606_trigger_handler,
+ &ad7606_buffer_ops);
+ if (ret)
+ return ret;
+ }
return devm_iio_device_register(dev, indio_dev);
}
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index b26a11b2eba1..2c629a15cc33 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -61,6 +61,12 @@
#define AD7616_CHANNEL(num) AD7606_SW_CHANNEL(num, 16)
+#define AD7606_BI_CHANNEL(num) \
+ AD760X_CHANNEL(num, 0, \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 16)
+
struct ad7606_state;
typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
@@ -69,6 +75,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
/**
* struct ad7606_chip_info - chip specific information
* @channels: channel specification
+ * @max_samplerate: maximum supported samplerate
* @name device name
* @num_channels: number of channels
* @num_adc_channels the number of channels the ADC actually inputs.
@@ -82,6 +89,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
*/
struct ad7606_chip_info {
const struct iio_chan_spec *channels;
+ unsigned int max_samplerate;
const char *name;
unsigned int num_adc_channels;
unsigned int num_channels;
@@ -152,6 +160,7 @@ struct ad7606_state {
bool sw_mode_en;
const unsigned int *oversampling_avail;
unsigned int num_os_ratios;
+ struct iio_backend *back;
int (*write_scale)(struct iio_dev *indio_dev, int ch, int val);
int (*write_os)(struct iio_dev *indio_dev, int val);
@@ -180,16 +189,21 @@ struct ad7606_state {
/**
* struct ad7606_bus_ops - driver bus operations
+ * @iio_backend_config function pointer for configuring the iio_backend for
+ * the compatibles that use it
* @read_block function pointer for reading blocks of data
* @sw_mode_config: pointer to a function which configured the device
* for software mode
* @reg_read function pointer for reading spi register
* @reg_write function pointer for writing spi register
* @write_mask function pointer for write spi register with mask
+ * @update_scan_mode function pointer for handling the calls to iio_info's update_scan
+ * mode when enabling/disabling channels.
* @rd_wr_cmd pointer to the function which calculates the spi address
*/
struct ad7606_bus_ops {
/* more methods added in future? */
+ int (*iio_backend_config)(struct device *dev, struct iio_dev *indio_dev);
int (*read_block)(struct device *dev, int num, void *data);
int (*sw_mode_config)(struct iio_dev *indio_dev);
int (*reg_read)(struct ad7606_state *st, unsigned int addr);
@@ -200,6 +214,7 @@ struct ad7606_bus_ops {
unsigned int addr,
unsigned long mask,
unsigned int val);
+ int (*update_scan_mode)(struct iio_dev *indio_dev, const unsigned long *scan_mask);
u16 (*rd_wr_cmd)(int addr, char isWriteOp);
};
diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
index b87be2f1ca04..6946ff00e4cb 100644
--- a/drivers/iio/adc/ad7606_par.c
+++ b/drivers/iio/adc/ad7606_par.c
@@ -2,7 +2,8 @@
/*
* AD7606 Parallel Interface ADC driver
*
- * Copyright 2011 Analog Devices Inc.
+ * Copyright 2011 - 2024 Analog Devices Inc.
+ * Copyright 2024 BayLibre SAS.
*/
#include <linux/err.h>
@@ -14,9 +15,82 @@
#include <linux/property.h>
#include <linux/types.h>
+#include <linux/iio/backend.h>
#include <linux/iio/iio.h>
+
#include "ad7606.h"
+static const struct iio_chan_spec ad7606b_bi_channels[] = {
+ AD7606_BI_CHANNEL(0),
+ AD7606_BI_CHANNEL(1),
+ AD7606_BI_CHANNEL(2),
+ AD7606_BI_CHANNEL(3),
+ AD7606_BI_CHANNEL(4),
+ AD7606_BI_CHANNEL(5),
+ AD7606_BI_CHANNEL(6),
+ AD7606_BI_CHANNEL(7),
+};
+
+static int ad7606_bi_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask)
+{
+ struct ad7606_state *st = iio_priv(indio_dev);
+ unsigned int c, ret;
+
+ for (c = 0; c < indio_dev->num_channels; c++) {
+ if (test_bit(c, scan_mask))
+ ret = iio_backend_chan_enable(st->back, c);
+ else
+ ret = iio_backend_chan_disable(st->back, c);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ad7606_bi_setup_iio_backend(struct device *dev, struct iio_dev *indio_dev)
+{
+ struct ad7606_state *st = iio_priv(indio_dev);
+ unsigned int ret, c;
+ struct iio_backend_data_fmt data = {
+ .sign_extend = true,
+ .enable = true,
+ };
+
+ st->back = devm_iio_backend_get(dev, NULL);
+ if (IS_ERR(st->back))
+ return PTR_ERR(st->back);
+
+ /* If the device is iio_backend powered the PWM is mandatory */
+ if (!st->cnvst_pwm)
+ return dev_err_probe(st->dev, -EINVAL,
+ "A PWM is mandatory when using backend.\n");
+
+ ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_backend_enable(dev, st->back);
+ if (ret)
+ return ret;
+
+ for (c = 0; c < indio_dev->num_channels; c++) {
+ ret = iio_backend_data_format_set(st->back, c, &data);
+ if (ret)
+ return ret;
+ }
+
+ indio_dev->channels = ad7606b_bi_channels;
+ indio_dev->num_channels = 8;
+
+ return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_bi_bops = {
+ .iio_backend_config = ad7606_bi_setup_iio_backend,
+ .update_scan_mode = ad7606_bi_update_scan_mode,
+};
+
static int ad7606_par16_read_block(struct device *dev,
int count, void *buf)
{
@@ -96,9 +170,22 @@ static int ad7606_par_probe(struct platform_device *pdev)
void __iomem *addr;
resource_size_t remap_size;
int irq;
+ struct iio_backend *back;
+ /*
+ * If a firmware node is available (ACPI or DT), platform_device_id is null
+ * and we must use get_match_data.
+ */
if (dev_fwnode(&pdev->dev)) {
chip_info = device_get_match_data(&pdev->dev);
+ if (device_property_present(&pdev->dev, "io-backends"))
+ /*
+ * If a backend is available ,call the core probe with backend
+ * bops, otherwise use the former bops.
+ */
+ return ad7606_probe(&pdev->dev, 0, NULL,
+ chip_info,
+ &ad7606_bi_bops);
} else {
id = platform_get_device_id(pdev);
chip_info = (const struct ad7606_chip_info *)id->driver_data;
@@ -124,6 +211,7 @@ static const struct platform_device_id ad7606_driver_ids[] = {
{ .name = "ad7606-4", .driver_data = (kernel_ulong_t)&ad7606_4_info, },
{ .name = "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
{ .name = "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
+ { .name = "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
{ }
};
MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
@@ -133,6 +221,7 @@ static const struct of_device_id ad7606_of_match[] = {
{ .compatible = "adi,ad7606-4", .data = &ad7606_4_info },
{ .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
{ .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
+ { .compatible = "adi,ad7606b", .data = &ad7606b_info },
{ }
};
MODULE_DEVICE_TABLE(of, ad7606_of_match);
@@ -152,3 +241,4 @@ MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS(IIO_AD7606);
+MODULE_IMPORT_NS(IIO_BACKEND);
--
2.34.1On Tue, Oct 15, 2024 at 01:56:20PM +0000, Guillaume Stols wrote: > @@ -640,6 +665,14 @@ static int ad7606_read_raw(struct iio_dev *indio_dev, > case IIO_CHAN_INFO_OVERSAMPLING_RATIO: > *val = st->oversampling; > return IIO_VAL_INT; > + case IIO_CHAN_INFO_SAMP_FREQ: > + /* > + * TODO: return the real frequency intead of the requested one once > + * pwm_get_state_hw comes upstream. > + */ > + pwm_get_state(st->cnvst_pwm, &cnvst_pwm_state); > + *val = DIV_ROUND_CLOSEST_ULL(NSEC_PER_SEC, cnvst_pwm_state.period); > + return IIO_VAL_INT; > } > return -EINVAL; > } Being late to the party as the patch is already applied: ad7606_set_sampling_freq() uses DIV_ROUND_UP_ULL to determine the period from freq. So I guess you should a down-rounding div here to calculate freq from period. Having said that, pwm_get_state_hw() is in mainline and will be included in v6.13-rc1. Best regards Uwe
Hi Guillaume,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 465644ac29536d10178b5ca4684d0b84765b9fa4]
url: https://github.com/intel-lab-lkp/linux/commits/Guillaume-Stols/dt-bindings-iio-adc-ad7606-Remove-spi-cpha-from-required/20241015-215831
base: 465644ac29536d10178b5ca4684d0b84765b9fa4
patch link: https://lore.kernel.org/r/20241015-ad7606_add_iio_backend_support-v5-7-654faf1ae08c%40baylibre.com
patch subject: [PATCH v5 7/8] iio: adc: ad7606: Add iio-backend support
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20241019/202410190802.CLaySBOq-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241019/202410190802.CLaySBOq-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202410190802.CLaySBOq-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/iio/adc/ad7606_par.c:173:22: warning: unused variable 'back' [-Wunused-variable]
173 | struct iio_backend *back;
| ^~~~
1 warning generated.
vim +/back +173 drivers/iio/adc/ad7606_par.c
164
165 static int ad7606_par_probe(struct platform_device *pdev)
166 {
167 const struct ad7606_chip_info *chip_info;
168 const struct platform_device_id *id;
169 struct resource *res;
170 void __iomem *addr;
171 resource_size_t remap_size;
172 int irq;
> 173 struct iio_backend *back;
174
175 /*
176 * If a firmware node is available (ACPI or DT), platform_device_id is null
177 * and we must use get_match_data.
178 */
179 if (dev_fwnode(&pdev->dev)) {
180 chip_info = device_get_match_data(&pdev->dev);
181 if (device_property_present(&pdev->dev, "io-backends"))
182 /*
183 * If a backend is available ,call the core probe with backend
184 * bops, otherwise use the former bops.
185 */
186 return ad7606_probe(&pdev->dev, 0, NULL,
187 chip_info,
188 &ad7606_bi_bops);
189 } else {
190 id = platform_get_device_id(pdev);
191 chip_info = (const struct ad7606_chip_info *)id->driver_data;
192 }
193
194 irq = platform_get_irq(pdev, 0);
195 if (irq < 0)
196 return irq;
197
198 addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
199 if (IS_ERR(addr))
200 return PTR_ERR(addr);
201
202 remap_size = resource_size(res);
203
204 return ad7606_probe(&pdev->dev, irq, addr, chip_info,
205 remap_size > 1 ? &ad7606_par16_bops :
206 &ad7606_par8_bops);
207 }
208
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
On 10/15/24 15:56, Guillaume Stols wrote:
> - Basic support for iio backend.
> - Supports IIO_CHAN_INFO_SAMP_FREQ R/W.
> - Only hardware mode is available, and that IIO_CHAN_INFO_RAW is not
> supported if iio-backend mode is selected.
>
> Signed-off-by: Guillaume Stols <gstols@baylibre.com>
> ---
> drivers/iio/adc/Kconfig | 2 +
> drivers/iio/adc/ad7606.c | 154 ++++++++++++++++++++++++++++++++++---------
> drivers/iio/adc/ad7606.h | 15 +++++
> drivers/iio/adc/ad7606_par.c | 92 +++++++++++++++++++++++++-
> 4 files changed, 231 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 91873f60322d..a57b5f0bc070 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -224,9 +224,11 @@ config AD7606_IFACE_PARALLEL
> tristate "Analog Devices AD7606 ADC driver with parallel interface support"
> depends on HAS_IOPORT
> select AD7606
> + select IIO_BACKEND
> help
> Say yes here to build parallel interface support for Analog Devices:
> ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
> + It also support iio_backended devices for AD7606B.
>
> To compile this driver as a module, choose M here: the
> module will be called ad7606_par.
> diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> index 34d377e9ac79..7871552ce5ac 100644
> --- a/drivers/iio/adc/ad7606.c
> +++ b/drivers/iio/adc/ad7606.c
> @@ -21,6 +21,7 @@
> #include <linux/units.h>
> #include <linux/util_macros.h>
>
> +#include <linux/iio/backend.h>
> #include <linux/iio/buffer.h>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> @@ -191,6 +192,7 @@ EXPORT_SYMBOL_NS_GPL(ad7606_4_info, IIO_AD7606);
>
> const struct ad7606_chip_info ad7606b_info = {
> .channels = ad7606_channels_16bit,
> + .max_samplerate = 800 * KILO,
> .name = "ad7606b",
> .num_adc_channels = 8,
> .num_channels = 9,
> @@ -490,6 +492,17 @@ static int ad7606_pwm_set_low(struct ad7606_state *st)
> return ret;
> }
>
> +static int ad7606_pwm_set_swing(struct ad7606_state *st)
> +{
> + struct pwm_state cnvst_pwm_state;
> +
> + pwm_get_state(st->cnvst_pwm, &cnvst_pwm_state);
> + cnvst_pwm_state.enabled = true;
> + cnvst_pwm_state.duty_cycle = cnvst_pwm_state.period / 2;
> +
> + return pwm_apply_might_sleep(st->cnvst_pwm, &cnvst_pwm_state);
> +}
> +
> static bool ad7606_pwm_is_swinging(struct ad7606_state *st)
> {
> struct pwm_state cnvst_pwm_state;
> @@ -576,11 +589,22 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch,
> if (ret < 0)
> return ret;
> }
> - ret = wait_for_completion_timeout(&st->completion,
> - msecs_to_jiffies(1000));
> - if (!ret) {
> - ret = -ETIMEDOUT;
> - goto error_ret;
> +
> + /*
> + * If no backend, wait for the interruption on busy pin, otherwise just add
> + * a delay to leave time for the data to be available. For now, the latter
> + * will not happen because IIO_CHAN_INFO_RAW is not supported for the backend.
> + * TODO: Add support for reading a single value when the backend is used.
> + */
> + if (!st->back) {
> + ret = wait_for_completion_timeout(&st->completion,
> + msecs_to_jiffies(1000));
> + if (!ret) {
> + ret = -ETIMEDOUT;
> + goto error_ret;
> + }
> + } else {
> + fsleep(1);
> }
>
> ret = ad7606_read_samples(st);
> @@ -620,6 +644,7 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
> int ret, ch = 0;
> struct ad7606_state *st = iio_priv(indio_dev);
> struct ad7606_chan_scale *cs;
> + struct pwm_state cnvst_pwm_state;
>
> switch (m) {
> case IIO_CHAN_INFO_RAW:
> @@ -640,6 +665,14 @@ static int ad7606_read_raw(struct iio_dev *indio_dev,
> case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> *val = st->oversampling;
> return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + /*
> + * TODO: return the real frequency intead of the requested one once
> + * pwm_get_state_hw comes upstream.
> + */
> + pwm_get_state(st->cnvst_pwm, &cnvst_pwm_state);
> + *val = DIV_ROUND_CLOSEST_ULL(NSEC_PER_SEC, cnvst_pwm_state.period);
> + return IIO_VAL_INT;
> }
> return -EINVAL;
> }
> @@ -732,6 +765,10 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
> return ret;
>
> return 0;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + if (val < 0 && val2 != 0)
> + return -EINVAL;
> + return ad7606_set_sampling_freq(st, val);
> default:
> return -EINVAL;
> }
> @@ -914,14 +951,50 @@ static int ad7606_read_avail(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> +static int ad7606_backend_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + return ad7606_pwm_set_swing(st);
> +}
> +
> +static int ad7606_backend_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + return ad7606_pwm_set_low(st);
> +}
> +
> +static int ad7606_update_scan_mode(struct iio_dev *indio_dev,
> + const unsigned long *scan_mask)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + /*
> + * The update scan mode is only for iio backend compatible drivers.
> + * If the specific update_scan_mode is not defined in the bus ops,
> + * just do nothing and return 0.
> + */
> + if (!st->bops->update_scan_mode)
> + return 0;
> +
> + return st->bops->update_scan_mode(indio_dev, scan_mask);
> +}
> +
> static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
> .postenable = &ad7606_buffer_postenable,
> .predisable = &ad7606_buffer_predisable,
> };
>
> +static const struct iio_buffer_setup_ops ad7606_backend_buffer_ops = {
> + .postenable = &ad7606_backend_buffer_postenable,
> + .predisable = &ad7606_backend_buffer_predisable,
> +};
> +
> static const struct iio_info ad7606_info_no_os_or_range = {
> .read_raw = &ad7606_read_raw,
> .validate_trigger = &ad7606_validate_trigger,
> + .update_scan_mode = &ad7606_update_scan_mode,
> };
>
> static const struct iio_info ad7606_info_os_and_range = {
> @@ -929,6 +1002,7 @@ static const struct iio_info ad7606_info_os_and_range = {
> .write_raw = &ad7606_write_raw,
> .attrs = &ad7606_attribute_group_os_and_range,
> .validate_trigger = &ad7606_validate_trigger,
> + .update_scan_mode = &ad7606_update_scan_mode,
> };
>
> static const struct iio_info ad7606_info_sw_mode = {
> @@ -937,6 +1011,7 @@ static const struct iio_info ad7606_info_sw_mode = {
> .read_avail = &ad7606_read_avail,
> .debugfs_reg_access = &ad7606_reg_access,
> .validate_trigger = &ad7606_validate_trigger,
> + .update_scan_mode = &ad7606_update_scan_mode,
> };
>
> static const struct iio_info ad7606_info_os = {
> @@ -944,6 +1019,7 @@ static const struct iio_info ad7606_info_os = {
> .write_raw = &ad7606_write_raw,
> .attrs = &ad7606_attribute_group_os,
> .validate_trigger = &ad7606_validate_trigger,
> + .update_scan_mode = &ad7606_update_scan_mode,
> };
>
> static const struct iio_info ad7606_info_range = {
> @@ -951,6 +1027,7 @@ static const struct iio_info ad7606_info_range = {
> .write_raw = &ad7606_write_raw,
> .attrs = &ad7606_attribute_group_range,
> .validate_trigger = &ad7606_validate_trigger,
> + .update_scan_mode = &ad7606_update_scan_mode,
> };
>
> static const struct iio_trigger_ops ad7606_trigger_ops = {
> @@ -1070,8 +1147,6 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> indio_dev->channels = st->chip_info->channels;
> indio_dev->num_channels = st->chip_info->num_channels;
>
> - init_completion(&st->completion);
> -
> ret = ad7606_reset(st);
> if (ret)
> dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
> @@ -1118,34 +1193,51 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> if (ret)
> return ret;
> }
> - st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
> - indio_dev->name,
> - iio_device_id(indio_dev));
> - if (!st->trig)
> - return -ENOMEM;
>
> - st->trig->ops = &ad7606_trigger_ops;
> - iio_trigger_set_drvdata(st->trig, indio_dev);
> - ret = devm_iio_trigger_register(dev, st->trig);
> - if (ret)
> - return ret;
> + if (st->bops->iio_backend_config) {
> + /*
> + * If there is a backend, the PWM should not overpass the maximum sampling
> + * frequency the chip supports.
> + */
> + ret = ad7606_set_sampling_freq(st,
> + chip_info->max_samplerate ? : 2 * KILO);
> + if (ret)
> + return ret;
> +
> + ret = st->bops->iio_backend_config(dev, indio_dev);
> + if (ret)
> + return ret;
>
> - indio_dev->trig = iio_trigger_get(st->trig);
> + indio_dev->setup_ops = &ad7606_backend_buffer_ops;
> + } else {
> + init_completion(&st->completion);
> + st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
> + indio_dev->name,
> + iio_device_id(indio_dev));
> + if (!st->trig)
> + return -ENOMEM;
> +
> + st->trig->ops = &ad7606_trigger_ops;
> + iio_trigger_set_drvdata(st->trig, indio_dev);
> + ret = devm_iio_trigger_register(dev, st->trig);
> + if (ret)
> + return ret;
>
> - ret = devm_request_threaded_irq(dev, irq,
> - NULL,
> - &ad7606_interrupt,
> - IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> - chip_info->name, indio_dev);
> - if (ret)
> - return ret;
> + indio_dev->trig = iio_trigger_get(st->trig);
>
> - ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
> - &iio_pollfunc_store_time,
> - &ad7606_trigger_handler,
> - &ad7606_buffer_ops);
> - if (ret)
> - return ret;
> + ret = devm_request_threaded_irq(dev, irq, NULL, &ad7606_interrupt,
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + chip_info->name, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
> + &iio_pollfunc_store_time,
> + &ad7606_trigger_handler,
> + &ad7606_buffer_ops);
> + if (ret)
> + return ret;
> + }
>
> return devm_iio_device_register(dev, indio_dev);
> }
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> index b26a11b2eba1..2c629a15cc33 100644
> --- a/drivers/iio/adc/ad7606.h
> +++ b/drivers/iio/adc/ad7606.h
> @@ -61,6 +61,12 @@
>
> #define AD7616_CHANNEL(num) AD7606_SW_CHANNEL(num, 16)
>
> +#define AD7606_BI_CHANNEL(num) \
> + AD760X_CHANNEL(num, 0, \
> + BIT(IIO_CHAN_INFO_SCALE), \
> + BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
> + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 16)
> +
> struct ad7606_state;
>
> typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
> @@ -69,6 +75,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
> /**
> * struct ad7606_chip_info - chip specific information
> * @channels: channel specification
> + * @max_samplerate: maximum supported samplerate
> * @name device name
> * @num_channels: number of channels
> * @num_adc_channels the number of channels the ADC actually inputs.
> @@ -82,6 +89,7 @@ typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st,
> */
> struct ad7606_chip_info {
> const struct iio_chan_spec *channels;
> + unsigned int max_samplerate;
> const char *name;
> unsigned int num_adc_channels;
> unsigned int num_channels;
> @@ -152,6 +160,7 @@ struct ad7606_state {
> bool sw_mode_en;
> const unsigned int *oversampling_avail;
> unsigned int num_os_ratios;
> + struct iio_backend *back;
> int (*write_scale)(struct iio_dev *indio_dev, int ch, int val);
> int (*write_os)(struct iio_dev *indio_dev, int val);
>
> @@ -180,16 +189,21 @@ struct ad7606_state {
>
> /**
> * struct ad7606_bus_ops - driver bus operations
> + * @iio_backend_config function pointer for configuring the iio_backend for
> + * the compatibles that use it
> * @read_block function pointer for reading blocks of data
> * @sw_mode_config: pointer to a function which configured the device
> * for software mode
> * @reg_read function pointer for reading spi register
> * @reg_write function pointer for writing spi register
> * @write_mask function pointer for write spi register with mask
> + * @update_scan_mode function pointer for handling the calls to iio_info's update_scan
> + * mode when enabling/disabling channels.
> * @rd_wr_cmd pointer to the function which calculates the spi address
> */
> struct ad7606_bus_ops {
> /* more methods added in future? */
> + int (*iio_backend_config)(struct device *dev, struct iio_dev *indio_dev);
> int (*read_block)(struct device *dev, int num, void *data);
> int (*sw_mode_config)(struct iio_dev *indio_dev);
> int (*reg_read)(struct ad7606_state *st, unsigned int addr);
> @@ -200,6 +214,7 @@ struct ad7606_bus_ops {
> unsigned int addr,
> unsigned long mask,
> unsigned int val);
> + int (*update_scan_mode)(struct iio_dev *indio_dev, const unsigned long *scan_mask);
> u16 (*rd_wr_cmd)(int addr, char isWriteOp);
> };
>
> diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
> index b87be2f1ca04..6946ff00e4cb 100644
> --- a/drivers/iio/adc/ad7606_par.c
> +++ b/drivers/iio/adc/ad7606_par.c
> @@ -2,7 +2,8 @@
> /*
> * AD7606 Parallel Interface ADC driver
> *
> - * Copyright 2011 Analog Devices Inc.
> + * Copyright 2011 - 2024 Analog Devices Inc.
> + * Copyright 2024 BayLibre SAS.
> */
>
> #include <linux/err.h>
> @@ -14,9 +15,82 @@
> #include <linux/property.h>
> #include <linux/types.h>
>
> +#include <linux/iio/backend.h>
> #include <linux/iio/iio.h>
> +
> #include "ad7606.h"
>
> +static const struct iio_chan_spec ad7606b_bi_channels[] = {
> + AD7606_BI_CHANNEL(0),
> + AD7606_BI_CHANNEL(1),
> + AD7606_BI_CHANNEL(2),
> + AD7606_BI_CHANNEL(3),
> + AD7606_BI_CHANNEL(4),
> + AD7606_BI_CHANNEL(5),
> + AD7606_BI_CHANNEL(6),
> + AD7606_BI_CHANNEL(7),
> +};
> +
> +static int ad7606_bi_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + unsigned int c, ret;
> +
> + for (c = 0; c < indio_dev->num_channels; c++) {
> + if (test_bit(c, scan_mask))
> + ret = iio_backend_chan_enable(st->back, c);
> + else
> + ret = iio_backend_chan_disable(st->back, c);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ad7606_bi_setup_iio_backend(struct device *dev, struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + unsigned int ret, c;
> + struct iio_backend_data_fmt data = {
> + .sign_extend = true,
> + .enable = true,
> + };
> +
> + st->back = devm_iio_backend_get(dev, NULL);
> + if (IS_ERR(st->back))
> + return PTR_ERR(st->back);
> +
> + /* If the device is iio_backend powered the PWM is mandatory */
> + if (!st->cnvst_pwm)
> + return dev_err_probe(st->dev, -EINVAL,
> + "A PWM is mandatory when using backend.\n");
> +
> + ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_iio_backend_enable(dev, st->back);
> + if (ret)
> + return ret;
> +
> + for (c = 0; c < indio_dev->num_channels; c++) {
> + ret = iio_backend_data_format_set(st->back, c, &data);
> + if (ret)
> + return ret;
> + }
> +
> + indio_dev->channels = ad7606b_bi_channels;
> + indio_dev->num_channels = 8;
> +
> + return 0;
> +}
> +
> +static const struct ad7606_bus_ops ad7606_bi_bops = {
> + .iio_backend_config = ad7606_bi_setup_iio_backend,
> + .update_scan_mode = ad7606_bi_update_scan_mode,
> +};
> +
> static int ad7606_par16_read_block(struct device *dev,
> int count, void *buf)
> {
> @@ -96,9 +170,22 @@ static int ad7606_par_probe(struct platform_device *pdev)
> void __iomem *addr;
> resource_size_t remap_size;
> int irq;
> + struct iio_backend *back;
Just spotted that I forgot to remove the declaration. Shall I send
another series with this correction ?
>
> + /*
> + * If a firmware node is available (ACPI or DT), platform_device_id is null
> + * and we must use get_match_data.
> + */
> if (dev_fwnode(&pdev->dev)) {
> chip_info = device_get_match_data(&pdev->dev);
> + if (device_property_present(&pdev->dev, "io-backends"))
> + /*
> + * If a backend is available ,call the core probe with backend
> + * bops, otherwise use the former bops.
> + */
> + return ad7606_probe(&pdev->dev, 0, NULL,
> + chip_info,
> + &ad7606_bi_bops);
> } else {
> id = platform_get_device_id(pdev);
> chip_info = (const struct ad7606_chip_info *)id->driver_data;
> @@ -124,6 +211,7 @@ static const struct platform_device_id ad7606_driver_ids[] = {
> { .name = "ad7606-4", .driver_data = (kernel_ulong_t)&ad7606_4_info, },
> { .name = "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
> { .name = "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
> + { .name = "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
> { }
> };
> MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
> @@ -133,6 +221,7 @@ static const struct of_device_id ad7606_of_match[] = {
> { .compatible = "adi,ad7606-4", .data = &ad7606_4_info },
> { .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
> { .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
> + { .compatible = "adi,ad7606b", .data = &ad7606b_info },
> { }
> };
> MODULE_DEVICE_TABLE(of, ad7606_of_match);
> @@ -152,3 +241,4 @@ MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
> MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
> MODULE_LICENSE("GPL v2");
> MODULE_IMPORT_NS(IIO_AD7606);
> +MODULE_IMPORT_NS(IIO_BACKEND);
>
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