]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
iio: adc: ad7606: Add iio-backend support
authorGuillaume Stols <gstols@baylibre.com>
Tue, 15 Oct 2024 13:56:20 +0000 (13:56 +0000)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Mon, 21 Oct 2024 18:19:26 +0000 (19:19 +0100)
- 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>
Link: https://patch.msgid.link/20241015-ad7606_add_iio_backend_support-v5-7-654faf1ae08c@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/iio/adc/Kconfig
drivers/iio/adc/ad7606.c
drivers/iio/adc/ad7606.h
drivers/iio/adc/ad7606_par.c

index 179d83aafd8a6ff85636d93d9e22cfa0220ac127..fa076774d4368f8108163429d979f1522e2e9d71 100644 (file)
@@ -226,9 +226,11 @@ 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.
index b5dffacfcc8336b5ce13eb088bb3e175816242e1..7953ea56edd0980cfc03dfb11ebcd732e8f68899 100644 (file)
@@ -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);
 }
index b26a11b2eba1a9b291d2a46dad0c5acd66b84ca7..2c629a15cc3397b49548711c24847e08077c89f0 100644 (file)
 
 #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);
 };
 
index b87be2f1ca043e66c6917eb60660e0bd1369d917..4e729777d373ce86e205d716598120181aea2296 100644 (file)
@@ -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>
 #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)
 {
@@ -97,8 +171,20 @@ static int ad7606_par_probe(struct platform_device *pdev)
        resource_size_t remap_size;
        int irq;
 
+       /*
+        * 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 +210,7 @@ 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 +220,7 @@ 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 +240,4 @@ 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);