iio: adc: adi-axi-adc: move to backend framework

Move to the IIO backend framework. Devices supported by adi-axi-adc now
register themselves as backend devices.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240210-iio-backend-v11-7-f5242a5fb42a@analog.com
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 6793faacb4dca15428bf3f97864a7a6310a456ff..02a55809cb6ab02ddd216e78622a285aa43667d1 100644 (file)
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -309,7 +309,7 @@ config ADI_AXI_ADC
        select IIO_BUFFER_HW_CONSUMER
        select IIO_BUFFER_DMAENGINE
        select REGMAP_MMIO
-       depends on OF
+       select IIO_BACKEND
        help
          Say yes here to build support for Analog Devices Generic
          AXI ADC IP core. The IP core is used for interfacing with

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 0f21d1d98b9fa50f71a5e6723c9f93dcc21d2ef9..4156639b3c8bdb5a4101dacc47dc665aa5db2166 100644 (file)
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -8,6 +8,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/clk.h>
+#include <linux/err.h>
 #include <linux/io.h>
 #include <linux/delay.h>
 #include <linux/module.h>
@@ -17,13 +18,12 @@
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
-#include <linux/iio/iio.h>
-#include <linux/iio/sysfs.h>
-#include <linux/iio/buffer.h>
-#include <linux/iio/buffer-dmaengine.h>
-
 #include <linux/fpga/adi-axi-common.h>
-#include <linux/iio/adc/adi-axi-adc.h>
+
+#include <linux/iio/backend.h>
+#include <linux/iio/buffer-dmaengine.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
 
 /*
  * Register definitions:
@@ -44,6 +44,7 @@
 #define   ADI_AXI_REG_CHAN_CTRL_PN_SEL_OWR     BIT(10)
 #define   ADI_AXI_REG_CHAN_CTRL_IQCOR_EN       BIT(9)
 #define   ADI_AXI_REG_CHAN_CTRL_DCFILT_EN      BIT(8)
+#define   ADI_AXI_REG_CHAN_CTRL_FMT_MASK       GENMASK(6, 4)
 #define   ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT    BIT(6)
 #define   ADI_AXI_REG_CHAN_CTRL_FMT_TYPE       BIT(5)
 #define   ADI_AXI_REG_CHAN_CTRL_FMT_EN         BIT(4)
@@ -55,286 +56,100 @@
         ADI_AXI_REG_CHAN_CTRL_FMT_EN |         \
         ADI_AXI_REG_CHAN_CTRL_ENABLE)
 
-struct adi_axi_adc_core_info {
-       unsigned int                            version;
-};
-
 struct adi_axi_adc_state {
-       struct mutex                            lock;
-
-       struct adi_axi_adc_client               *client;
        struct regmap                           *regmap;
-};
-
-struct adi_axi_adc_client {
-       struct list_head                        entry;
-       struct adi_axi_adc_conv                 conv;
-       struct adi_axi_adc_state                *state;
        struct device                           *dev;
-       const struct adi_axi_adc_core_info      *info;
 };
 
-static LIST_HEAD(registered_clients);
-static DEFINE_MUTEX(registered_clients_lock);
-
-static struct adi_axi_adc_client *conv_to_client(struct adi_axi_adc_conv *conv)
-{
-       return container_of(conv, struct adi_axi_adc_client, conv);
-}
-
-void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv)
-{
-       struct adi_axi_adc_client *cl = conv_to_client(conv);
-
-       return (char *)cl + ALIGN(sizeof(struct adi_axi_adc_client),
-                                 IIO_DMA_MINALIGN);
-}
-EXPORT_SYMBOL_NS_GPL(adi_axi_adc_conv_priv, IIO_ADI_AXI);
-
-static int adi_axi_adc_config_dma_buffer(struct device *dev,
-                                        struct iio_dev *indio_dev)
-{
-       const char *dma_name;
-
-       if (!device_property_present(dev, "dmas"))
-               return 0;
-
-       if (device_property_read_string(dev, "dma-names", &dma_name))
-               dma_name = "rx";
-
-       return devm_iio_dmaengine_buffer_setup(indio_dev->dev.parent,
-                                              indio_dev, dma_name);
-}
-
-static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
-                               struct iio_chan_spec const *chan,
-                               int *val, int *val2, long mask)
-{
-       struct adi_axi_adc_state *st = iio_priv(indio_dev);
-       struct adi_axi_adc_conv *conv = &st->client->conv;
-
-       if (!conv->read_raw)
-               return -EOPNOTSUPP;
-
-       return conv->read_raw(conv, chan, val, val2, mask);
-}
-
-static int adi_axi_adc_write_raw(struct iio_dev *indio_dev,
-                                struct iio_chan_spec const *chan,
-                                int val, int val2, long mask)
-{
-       struct adi_axi_adc_state *st = iio_priv(indio_dev);
-       struct adi_axi_adc_conv *conv = &st->client->conv;
-
-       if (!conv->write_raw)
-               return -EOPNOTSUPP;
-
-       return conv->write_raw(conv, chan, val, val2, mask);
-}
-
-static int adi_axi_adc_read_avail(struct iio_dev *indio_dev,
-                                 struct iio_chan_spec const *chan,
-                                 const int **vals, int *type, int *length,
-                                 long mask)
-{
-       struct adi_axi_adc_state *st = iio_priv(indio_dev);
-       struct adi_axi_adc_conv *conv = &st->client->conv;
-
-       if (!conv->read_avail)
-               return -EOPNOTSUPP;
-
-       return conv->read_avail(conv, chan, vals, type, length, mask);
-}
-
-static int adi_axi_adc_update_scan_mode(struct iio_dev *indio_dev,
-                                       const unsigned long *scan_mask)
+static int axi_adc_enable(struct iio_backend *back)
 {
-       struct adi_axi_adc_state *st = iio_priv(indio_dev);
-       struct adi_axi_adc_conv *conv = &st->client->conv;
-       unsigned int i;
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
        int ret;
 
-       for (i = 0; i < conv->chip_info->num_channels; i++) {
-               if (test_bit(i, scan_mask))
-                       ret = regmap_set_bits(st->regmap,
-                                             ADI_AXI_REG_CHAN_CTRL(i),
-                                             ADI_AXI_REG_CHAN_CTRL_ENABLE);
-               else
-                       ret = regmap_clear_bits(st->regmap,
-                                               ADI_AXI_REG_CHAN_CTRL(i),
-                                               ADI_AXI_REG_CHAN_CTRL_ENABLE);
-               if (ret)
-                       return ret;
-       }
-
-       return 0;
-}
-
-static struct adi_axi_adc_conv *adi_axi_adc_conv_register(struct device *dev,
-                                                         size_t sizeof_priv)
-{
-       struct adi_axi_adc_client *cl;
-       size_t alloc_size;
-
-       alloc_size = ALIGN(sizeof(struct adi_axi_adc_client), IIO_DMA_MINALIGN);
-       if (sizeof_priv)
-               alloc_size += ALIGN(sizeof_priv, IIO_DMA_MINALIGN);
-
-       cl = kzalloc(alloc_size, GFP_KERNEL);
-       if (!cl)
-               return ERR_PTR(-ENOMEM);
-
-       mutex_lock(&registered_clients_lock);
-
-       cl->dev = get_device(dev);
-
-       list_add_tail(&cl->entry, &registered_clients);
-
-       mutex_unlock(&registered_clients_lock);
+       ret = regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
+                             ADI_AXI_REG_RSTN_MMCM_RSTN);
+       if (ret)
+               return ret;
 
-       return &cl->conv;
+       fsleep(10000);
+       return regmap_set_bits(st->regmap, ADI_AXI_REG_RSTN,
+                              ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
 }
 
-static void adi_axi_adc_conv_unregister(struct adi_axi_adc_conv *conv)
+static void axi_adc_disable(struct iio_backend *back)
 {
-       struct adi_axi_adc_client *cl = conv_to_client(conv);
-
-       mutex_lock(&registered_clients_lock);
-
-       list_del(&cl->entry);
-       put_device(cl->dev);
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
 
-       mutex_unlock(&registered_clients_lock);
-
-       kfree(cl);
+       regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
 }
 
-static void devm_adi_axi_adc_conv_release(void *conv)
+static int axi_adc_data_format_set(struct iio_backend *back, unsigned int chan,
+                                  const struct iio_backend_data_fmt *data)
 {
-       adi_axi_adc_conv_unregister(conv);
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+       u32 val;
+
+       if (!data->enable)
+               return regmap_clear_bits(st->regmap,
+                                        ADI_AXI_REG_CHAN_CTRL(chan),
+                                        ADI_AXI_REG_CHAN_CTRL_FMT_EN);
+
+       val = FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_EN, true);
+       if (data->sign_extend)
+               val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_SIGNEXT, true);
+       if (data->type == IIO_BACKEND_OFFSET_BINARY)
+               val |= FIELD_PREP(ADI_AXI_REG_CHAN_CTRL_FMT_TYPE, true);
+
+       return regmap_update_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+                                 ADI_AXI_REG_CHAN_CTRL_FMT_MASK, val);
 }
 
-struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
-                                                       size_t sizeof_priv)
+static int axi_adc_chan_enable(struct iio_backend *back, unsigned int chan)
 {
-       struct adi_axi_adc_conv *conv;
-       int ret;
-
-       conv = adi_axi_adc_conv_register(dev, sizeof_priv);
-       if (IS_ERR(conv))
-               return conv;
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
 
-       ret = devm_add_action_or_reset(dev, devm_adi_axi_adc_conv_release,
-                                      conv);
-       if (ret)
-               return ERR_PTR(ret);
-
-       return conv;
+       return regmap_set_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+                              ADI_AXI_REG_CHAN_CTRL_ENABLE);
 }
-EXPORT_SYMBOL_NS_GPL(devm_adi_axi_adc_conv_register, IIO_ADI_AXI);
-
-static const struct iio_info adi_axi_adc_info = {
-       .read_raw = &adi_axi_adc_read_raw,
-       .write_raw = &adi_axi_adc_write_raw,
-       .update_scan_mode = &adi_axi_adc_update_scan_mode,
-       .read_avail = &adi_axi_adc_read_avail,
-};
-
-static const struct adi_axi_adc_core_info adi_axi_adc_10_0_a_info = {
-       .version = ADI_AXI_PCORE_VER(10, 0, 'a'),
-};
 
-static struct adi_axi_adc_client *adi_axi_adc_attach_client(struct device *dev)
+static int axi_adc_chan_disable(struct iio_backend *back, unsigned int chan)
 {
-       const struct adi_axi_adc_core_info *info;
-       struct adi_axi_adc_client *cl;
-       struct device_node *cln;
-
-       info = of_device_get_match_data(dev);
-       if (!info)
-               return ERR_PTR(-ENODEV);
-
-       cln = of_parse_phandle(dev->of_node, "adi,adc-dev", 0);
-       if (!cln) {
-               dev_err(dev, "No 'adi,adc-dev' node defined\n");
-               return ERR_PTR(-ENODEV);
-       }
-
-       mutex_lock(&registered_clients_lock);
-
-       list_for_each_entry(cl, &registered_clients, entry) {
-               if (!cl->dev)
-                       continue;
-
-               if (cl->dev->of_node != cln)
-                       continue;
-
-               if (!try_module_get(cl->dev->driver->owner)) {
-                       mutex_unlock(&registered_clients_lock);
-                       of_node_put(cln);
-                       return ERR_PTR(-ENODEV);
-               }
-
-               get_device(cl->dev);
-               cl->info = info;
-               mutex_unlock(&registered_clients_lock);
-               of_node_put(cln);
-               return cl;
-       }
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
 
-       mutex_unlock(&registered_clients_lock);
-       of_node_put(cln);
-
-       return ERR_PTR(-EPROBE_DEFER);
+       return regmap_clear_bits(st->regmap, ADI_AXI_REG_CHAN_CTRL(chan),
+                                ADI_AXI_REG_CHAN_CTRL_ENABLE);
 }
 
-static int adi_axi_adc_setup_channels(struct device *dev,
-                                     struct adi_axi_adc_state *st)
+static struct iio_buffer *axi_adc_request_buffer(struct iio_backend *back,
+                                                struct iio_dev *indio_dev)
 {
-       struct adi_axi_adc_conv *conv = &st->client->conv;
-       int i, ret;
+       struct adi_axi_adc_state *st = iio_backend_get_priv(back);
+       struct iio_buffer *buffer;
+       const char *dma_name;
+       int ret;
 
-       if (conv->preenable_setup) {
-               ret = conv->preenable_setup(conv);
-               if (ret)
-                       return ret;
-       }
+       if (device_property_read_string(st->dev, "dma-names", &dma_name))
+               dma_name = "rx";
 
-       for (i = 0; i < conv->chip_info->num_channels; i++) {
-               ret = regmap_write(st->regmap, ADI_AXI_REG_CHAN_CTRL(i),
-                                  ADI_AXI_REG_CHAN_CTRL_DEFAULTS);
-               if (ret)
-                       return ret;
+       buffer = iio_dmaengine_buffer_alloc(st->dev, dma_name);
+       if (IS_ERR(buffer)) {
+               dev_err(st->dev, "Could not get DMA buffer, %ld\n",
+                       PTR_ERR(buffer));
+               return ERR_CAST(buffer);
        }
 
-       return 0;
-}
-
-static int axi_adc_reset(struct adi_axi_adc_state *st)
-{
-       int ret;
-
-       ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
-       if (ret)
-               return ret;
-
-       mdelay(10);
-       ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN,
-                          ADI_AXI_REG_RSTN_MMCM_RSTN);
+       indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+       ret = iio_device_attach_buffer(indio_dev, buffer);
        if (ret)
-               return ret;
+               return ERR_PTR(ret);
 
-       mdelay(10);
-       return regmap_write(st->regmap, ADI_AXI_REG_RSTN,
-                           ADI_AXI_REG_RSTN_RSTN | ADI_AXI_REG_RSTN_MMCM_RSTN);
+       return buffer;
 }
 
-static void adi_axi_adc_cleanup(void *data)
+static void axi_adc_free_buffer(struct iio_backend *back,
+                               struct iio_buffer *buffer)
 {
-       struct adi_axi_adc_client *cl = data;
-
-       put_device(cl->dev);
-       module_put(cl->dev->driver->owner);
+       iio_dmaengine_buffer_free(buffer);
 }
 
 static const struct regmap_config axi_adc_regmap_config = {
@@ -344,45 +159,47 @@ static const struct regmap_config axi_adc_regmap_config = {
        .max_register = 0x0800,
 };
 
+static const struct iio_backend_ops adi_axi_adc_generic = {
+       .enable = axi_adc_enable,
+       .disable = axi_adc_disable,
+       .data_format_set = axi_adc_data_format_set,
+       .chan_enable = axi_adc_chan_enable,
+       .chan_disable = axi_adc_chan_disable,
+       .request_buffer = axi_adc_request_buffer,
+       .free_buffer = axi_adc_free_buffer,
+};
+
 static int adi_axi_adc_probe(struct platform_device *pdev)
 {
-       struct adi_axi_adc_conv *conv;
-       struct iio_dev *indio_dev;
-       struct adi_axi_adc_client *cl;
+       const unsigned int *expected_ver;
        struct adi_axi_adc_state *st;
        void __iomem *base;
        unsigned int ver;
        int ret;
 
-       cl = adi_axi_adc_attach_client(&pdev->dev);
-       if (IS_ERR(cl))
-               return PTR_ERR(cl);
-
-       ret = devm_add_action_or_reset(&pdev->dev, adi_axi_adc_cleanup, cl);
-       if (ret)
-               return ret;
-
-       indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
-       if (indio_dev == NULL)
+       st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
+       if (!st)
                return -ENOMEM;
 
-       st = iio_priv(indio_dev);
-       st->client = cl;
-       cl->state = st;
-       mutex_init(&st->lock);
-
        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);
 
+       st->dev = &pdev->dev;
        st->regmap = devm_regmap_init_mmio(&pdev->dev, base,
                                           &axi_adc_regmap_config);
        if (IS_ERR(st->regmap))
                return PTR_ERR(st->regmap);
 
-       conv = &st->client->conv;
+       expected_ver = device_get_match_data(&pdev->dev);
+       if (!expected_ver)
+               return -ENODEV;
 
-       ret = axi_adc_reset(st);
+       /*
+        * Force disable the core. Up to the frontend to enable us. And we can
+        * still read/write registers...
+        */
+       ret = regmap_write(st->regmap, ADI_AXI_REG_RSTN, 0);
        if (ret)
                return ret;
 
@@ -390,33 +207,19 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
-       if (cl->info->version > ver) {
+       if (*expected_ver > ver) {
                dev_err(&pdev->dev,
                        "IP core version is too old. Expected %d.%.2d.%c, Reported %d.%.2d.%c\n",
-                       ADI_AXI_PCORE_VER_MAJOR(cl->info->version),
-                       ADI_AXI_PCORE_VER_MINOR(cl->info->version),
-                       ADI_AXI_PCORE_VER_PATCH(cl->info->version),
+                       ADI_AXI_PCORE_VER_MAJOR(*expected_ver),
+                       ADI_AXI_PCORE_VER_MINOR(*expected_ver),
+                       ADI_AXI_PCORE_VER_PATCH(*expected_ver),
                        ADI_AXI_PCORE_VER_MAJOR(ver),
                        ADI_AXI_PCORE_VER_MINOR(ver),
                        ADI_AXI_PCORE_VER_PATCH(ver));
                return -ENODEV;
        }
 
-       indio_dev->info = &adi_axi_adc_info;
-       indio_dev->name = "adi-axi-adc";
-       indio_dev->modes = INDIO_DIRECT_MODE;
-       indio_dev->num_channels = conv->chip_info->num_channels;
-       indio_dev->channels = conv->chip_info->channels;
-
-       ret = adi_axi_adc_config_dma_buffer(&pdev->dev, indio_dev);
-       if (ret)
-               return ret;
-
-       ret = adi_axi_adc_setup_channels(&pdev->dev, st);
-       if (ret)
-               return ret;
-
-       ret = devm_iio_device_register(&pdev->dev, indio_dev);
+       ret = devm_iio_backend_register(&pdev->dev, &adi_axi_adc_generic, st);
        if (ret)
                return ret;
 
@@ -428,6 +231,8 @@ static int adi_axi_adc_probe(struct platform_device *pdev)
        return 0;
 }
 
+static unsigned int adi_axi_adc_10_0_a_info = ADI_AXI_PCORE_VER(10, 0, 'a');
+
 /* Match table for of_platform binding */
 static const struct of_device_id adi_axi_adc_of_match[] = {
        { .compatible = "adi,axi-adc-10.0.a", .data = &adi_axi_adc_10_0_a_info },
@@ -448,3 +253,4 @@ MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices Generic AXI ADC IP core driver");
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(IIO_DMAENGINE_BUFFER);
+MODULE_IMPORT_NS(IIO_BACKEND);

diff --git a/include/linux/iio/adc/adi-axi-adc.h b/include/linux/iio/adc/adi-axi-adc.h
deleted file mode 100644 (file)
index b790499..0000000
--- a/include/linux/iio/adc/adi-axi-adc.h
+++ /dev/null
@@ -1,68 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Analog Devices Generic AXI ADC IP core driver/library
- * Link: https://wiki.analog.com/resources/fpga/docs/axi_adc_ip
- *
- * Copyright 2012-2020 Analog Devices Inc.
- */
-#ifndef __ADI_AXI_ADC_H__
-#define __ADI_AXI_ADC_H__
-
-struct device;
-struct iio_chan_spec;
-
-/**
- * struct adi_axi_adc_chip_info - Chip specific information
- * @name               Chip name
- * @id                 Chip ID (usually product ID)
- * @channels           Channel specifications of type @struct iio_chan_spec
- * @num_channels       Number of @channels
- * @scale_table                Supported scales by the chip; tuples of 2 ints
- * @num_scales         Number of scales in the table
- * @max_rate           Maximum sampling rate supported by the device
- */
-struct adi_axi_adc_chip_info {
-       const char                      *name;
-       unsigned int                    id;
-
-       const struct iio_chan_spec      *channels;
-       unsigned int                    num_channels;
-
-       const unsigned int              (*scale_table)[2];
-       int                             num_scales;
-
-       unsigned long                   max_rate;
-};
-
-/**
- * struct adi_axi_adc_conv - data of the ADC attached to the AXI ADC
- * @chip_info          chip info details for the client ADC
- * @preenable_setup    op to run in the client before enabling the AXI ADC
- * @reg_access         IIO debugfs_reg_access hook for the client ADC
- * @read_raw           IIO read_raw hook for the client ADC
- * @write_raw          IIO write_raw hook for the client ADC
- * @read_avail         IIO read_avail hook for the client ADC
- */
-struct adi_axi_adc_conv {
-       const struct adi_axi_adc_chip_info              *chip_info;
-
-       int (*preenable_setup)(struct adi_axi_adc_conv *conv);
-       int (*reg_access)(struct adi_axi_adc_conv *conv, unsigned int reg,
-                         unsigned int writeval, unsigned int *readval);
-       int (*read_raw)(struct adi_axi_adc_conv *conv,
-                       struct iio_chan_spec const *chan,
-                       int *val, int *val2, long mask);
-       int (*write_raw)(struct adi_axi_adc_conv *conv,
-                        struct iio_chan_spec const *chan,
-                        int val, int val2, long mask);
-       int (*read_avail)(struct adi_axi_adc_conv *conv,
-                         struct iio_chan_spec const *chan,
-                         const int **val, int *type, int *length, long mask);
-};
-
-struct adi_axi_adc_conv *devm_adi_axi_adc_conv_register(struct device *dev,
-                                                       size_t sizeof_priv);
-
-void *adi_axi_adc_conv_priv(struct adi_axi_adc_conv *conv);
-
-#endif