[RFC PATCH] iio: adc: ti-ads1015: Refactor code to support SPI

From: Georgiana Chelu
Date: Fri Feb 09 2018 - 12:38:33 EST

We want to add support for ads1118 which uses SPI interface.
In order to do that we first refactor existing code into a core
part (bus independent) and an I2C part for current supported
devices.

Next patch will introduce support for ADS1118 which uses
SPI bus for communication.

Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
Signed-off-by: Georgiana Chelu <georgiana.chelu93@xxxxxxxxx>
---
We are sending this as a RFC for now to get your opinion on the
split. Still working on testing the SPI part.

drivers/iio/adc/Kconfig | 12 ++-
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads1015.c | 194 +++++++++++----------------------------
drivers/iio/adc/ti-ads1015.h | 63 +++++++++++++
drivers/iio/adc/ti-ads1015_i2c.c | 80 ++++++++++++++++
5 files changed, 204 insertions(+), 146 deletions(-)
create mode 100644 drivers/iio/adc/ti-ads1015.h
create mode 100644 drivers/iio/adc/ti-ads1015_i2c.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 10f3ede91d3a..846793a0e827 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -774,17 +774,21 @@ config TI_ADC161S626
called ti-adc161s626.

config TI_ADS1015
- tristate "Texas Instruments ADS1015 ADC"
- depends on I2C && !SENSORS_ADS1015
- select REGMAP_I2C
+ tristate
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
+
+config TI_ADS1015_I2C
+ tristate "Texas Instruments ADS1015 I2C ADC"
+ depends on I2C && !SENSORS_ADS1015
+ select REGMAP_I2C
+ select TI_ADS1015
help
If you say yes here you get support for Texas Instruments ADS1015
ADC chip.

This driver can also be built as a module. If so, the module will be
- called ti-ads1015.
+ called ti-ads1015_i2c.

config TI_ADS7950
tristate "Texas Instruments ADS7950 ADC driver"
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 9572c1090f35..c5c30b7cda64 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_TI_ADC108S102) += ti-adc108s102.o
obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
+obj-$(CONFIG_TI_ADS1015_I2C) += ti-ads1015_i2c.o
obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 6a114dcb4a3a..62898a0da4dd 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -6,19 +6,12 @@
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
- *
- * IIO driver for ADS1015 ADC 7-bit I2C slave address:
- * * 0x48 - ADDR connected to Ground
- * * 0x49 - ADDR connected to Vdd
- * * 0x4A - ADDR connected to SDA
- * * 0x4B - ADDR connected to SCL
*/

#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/init.h>
#include <linux/irq.h>
-#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/pm_runtime.h>
#include <linux/mutex.h>
@@ -34,55 +27,7 @@
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>

-#define ADS1015_DRV_NAME "ads1015"
-
-#define ADS1015_CONV_REG 0x00
-#define ADS1015_CFG_REG 0x01
-#define ADS1015_LO_THRESH_REG 0x02
-#define ADS1015_HI_THRESH_REG 0x03
-
-#define ADS1015_CFG_COMP_QUE_SHIFT 0
-#define ADS1015_CFG_COMP_LAT_SHIFT 2
-#define ADS1015_CFG_COMP_POL_SHIFT 3
-#define ADS1015_CFG_COMP_MODE_SHIFT 4
-#define ADS1015_CFG_DR_SHIFT 5
-#define ADS1015_CFG_MOD_SHIFT 8
-#define ADS1015_CFG_PGA_SHIFT 9
-#define ADS1015_CFG_MUX_SHIFT 12
-
-#define ADS1015_CFG_COMP_QUE_MASK GENMASK(1, 0)
-#define ADS1015_CFG_COMP_LAT_MASK BIT(2)
-#define ADS1015_CFG_COMP_POL_MASK BIT(3)
-#define ADS1015_CFG_COMP_MODE_MASK BIT(4)
-#define ADS1015_CFG_DR_MASK GENMASK(7, 5)
-#define ADS1015_CFG_MOD_MASK BIT(8)
-#define ADS1015_CFG_PGA_MASK GENMASK(11, 9)
-#define ADS1015_CFG_MUX_MASK GENMASK(14, 12)
-
-/* Comparator queue and disable field */
-#define ADS1015_CFG_COMP_DISABLE 3
-
-/* Comparator polarity field */
-#define ADS1015_CFG_COMP_POL_LOW 0
-#define ADS1015_CFG_COMP_POL_HIGH 1
-
-/* Comparator mode field */
-#define ADS1015_CFG_COMP_MODE_TRAD 0
-#define ADS1015_CFG_COMP_MODE_WINDOW 1
-
-/* device operating modes */
-#define ADS1015_CONTINUOUS 0
-#define ADS1015_SINGLESHOT 1
-
-#define ADS1015_SLEEP_DELAY_MS 2000
-#define ADS1015_DEFAULT_PGA 2
-#define ADS1015_DEFAULT_DATA_RATE 4
-#define ADS1015_DEFAULT_CHAN 0
-
-enum chip_ids {
- ADS1015,
- ADS1115,
-};
+#include "ti-ads1015.h"

enum ads1015_channels {
ADS1015_AIN0_AIN1 = 0,
@@ -229,6 +174,8 @@ struct ads1015_thresh_data {
};

struct ads1015_data {
+ enum chip_ids chip_id;
+ struct device *dev;
struct regmap *regmap;
/*
* Protects ADC ops, e.g: concurrent sysfs/buffered
@@ -281,12 +228,13 @@ static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
}
}

-static const struct regmap_config ads1015_regmap_config = {
+const struct regmap_config ads1015_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.max_register = ADS1015_HI_THRESH_REG,
.writeable_reg = ads1015_is_writeable_reg,
};
+EXPORT_SYMBOL(ads1015_regmap_config);

static const struct iio_chan_spec ads1015_channels[] = {
ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
@@ -841,31 +789,29 @@ static const struct iio_info ads1115_info = {
};

#ifdef CONFIG_OF
-static int ads1015_get_channels_config_of(struct i2c_client *client)
+static int ads1015_get_channels_config_of(struct ads1015_data *data)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(client);
- struct ads1015_data *data = iio_priv(indio_dev);
struct device_node *node;

- if (!client->dev.of_node ||
- !of_get_next_child(client->dev.of_node, NULL))
+ if (!data->dev->of_node ||
+ !of_get_next_child(data->dev->of_node, NULL))
return -EINVAL;

- for_each_child_of_node(client->dev.of_node, node) {
+ for_each_child_of_node(data->dev->of_node, node) {
u32 pval;
unsigned int channel;
unsigned int pga = ADS1015_DEFAULT_PGA;
unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;

if (of_property_read_u32(node, "reg", &pval)) {
- dev_err(&client->dev, "invalid reg on %pOF\n",
+ dev_err(data->dev, "invalid reg on %pOF\n",
node);
continue;
}

channel = pval;
if (channel >= ADS1015_CHANNELS) {
- dev_err(&client->dev,
+ dev_err(data->dev,
"invalid channel index %d on %pOF\n",
channel, node);
continue;
@@ -874,7 +820,7 @@ static int ads1015_get_channels_config_of(struct i2c_client *client)
if (!of_property_read_u32(node, "ti,gain", &pval)) {
pga = pval;
if (pga > 6) {
- dev_err(&client->dev, "invalid gain on %pOF\n",
+ dev_err(data->dev, "invalid gain on %pOF\n",
node);
of_node_put(node);
return -EINVAL;
@@ -884,7 +830,7 @@ static int ads1015_get_channels_config_of(struct i2c_client *client)
if (!of_property_read_u32(node, "ti,datarate", &pval)) {
data_rate = pval;
if (data_rate > 7) {
- dev_err(&client->dev,
+ dev_err(data->dev,
"invalid data_rate on %pOF\n",
node);
of_node_put(node);
@@ -900,13 +846,12 @@ static int ads1015_get_channels_config_of(struct i2c_client *client)
}
#endif

-static void ads1015_get_channels_config(struct i2c_client *client)
+static void ads1015_get_channels_config(struct ads1015_data *data)
{
unsigned int k;
+ struct ads1015_platform_data *pdata;

- struct iio_dev *indio_dev = i2c_get_clientdata(client);
- struct ads1015_data *data = iio_priv(indio_dev);
- struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
+ pdata = dev_get_platdata(data->dev);

/* prefer platform data */
if (pdata) {
@@ -916,7 +861,7 @@ static void ads1015_get_channels_config(struct i2c_client *client)
}

#ifdef CONFIG_OF
- if (!ads1015_get_channels_config_of(client))
+ if (!ads1015_get_channels_config_of(data))
return;
#endif
/* fallback on default configuration */
@@ -933,33 +878,32 @@ static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
mode << ADS1015_CFG_MOD_SHIFT);
}

-static int ads1015_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+int ads1015_core_probe(struct device *dev, struct regmap *regmap,
+ const char *name, int irq, unsigned int chip_id)
{
struct iio_dev *indio_dev;
struct ads1015_data *data;
- int ret;
+ int ret, i;
enum chip_ids chip;
- int i;

- indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;

data = iio_priv(indio_dev);
- i2c_set_clientdata(client, indio_dev);
+ dev_set_drvdata(dev, data);

mutex_init(&data->lock);

- indio_dev->dev.parent = &client->dev;
- indio_dev->dev.of_node = client->dev.of_node;
- indio_dev->name = ADS1015_DRV_NAME;
+ indio_dev->dev.parent = dev;
+ indio_dev->dev.of_node = dev->of_node;
+ indio_dev->name = name;
indio_dev->modes = INDIO_DIRECT_MODE;

- if (client->dev.of_node)
- chip = (enum chip_ids)of_device_get_match_data(&client->dev);
+ if (dev->of_node)
+ chip = (enum chip_ids)of_device_get_match_data(dev);
else
- chip = id->driver_data;
+ chip = chip_id;
switch (chip) {
case ADS1015:
indio_dev->channels = ads1015_channels;
@@ -988,25 +932,21 @@ static int ads1015_probe(struct i2c_client *client,
}

/* we need to keep this ABI the same as used by hwmon ADS1015 driver */
- ads1015_get_channels_config(client);
+ ads1015_get_channels_config(data);

- data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
- if (IS_ERR(data->regmap)) {
- dev_err(&client->dev, "Failed to allocate register map\n");
- return PTR_ERR(data->regmap);
- }
+ data->regmap = regmap;

- ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
ads1015_trigger_handler,
&ads1015_buffer_setup_ops);
if (ret < 0) {
- dev_err(&client->dev, "iio triggered buffer setup failed\n");
+ dev_err(dev, "iio triggered buffer setup failed\n");
return ret;
}

- if (client->irq) {
+ if (irq) {
unsigned long irq_trig =
- irqd_get_trigger_type(irq_get_irq_data(client->irq));
+ irqd_get_trigger_type(irq_get_irq_data(irq));
unsigned int cfg_comp_mask = ADS1015_CFG_COMP_QUE_MASK |
ADS1015_CFG_COMP_LAT_MASK | ADS1015_CFG_COMP_POL_MASK;
unsigned int cfg_comp =
@@ -1031,10 +971,10 @@ static int ads1015_probe(struct i2c_client *client,
if (ret)
return ret;

- ret = devm_request_threaded_irq(&client->dev, client->irq,
+ ret = devm_request_threaded_irq(dev, irq,
NULL, ads1015_event_handler,
irq_trig | IRQF_ONESHOT,
- client->name, indio_dev);
+ name, indio_dev);
if (ret)
return ret;
}
@@ -1045,41 +985,43 @@ static int ads1015_probe(struct i2c_client *client,

data->conv_invalid = true;

- ret = pm_runtime_set_active(&client->dev);
+ ret = pm_runtime_set_active(dev);
if (ret)
return ret;
- pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
- pm_runtime_use_autosuspend(&client->dev);
- pm_runtime_enable(&client->dev);
+ pm_runtime_set_autosuspend_delay(dev, ADS1015_SLEEP_DELAY_MS);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_enable(dev);

ret = iio_device_register(indio_dev);
if (ret < 0) {
- dev_err(&client->dev, "Failed to register IIO device\n");
+ dev_err(dev, "Failed to register IIO device\n");
return ret;
}

return 0;
}
+EXPORT_SYMBOL(ads1015_core_probe);

-static int ads1015_remove(struct i2c_client *client)
+int ads1015_core_remove(struct device *dev)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ads1015_data *data = iio_priv(indio_dev);

iio_device_unregister(indio_dev);

- pm_runtime_disable(&client->dev);
- pm_runtime_set_suspended(&client->dev);
- pm_runtime_put_noidle(&client->dev);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);

/* power down single shot mode */
return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
}
+EXPORT_SYMBOL(ads1015_core_remove);

#ifdef CONFIG_PM
static int ads1015_runtime_suspend(struct device *dev)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ads1015_data *data = iio_priv(indio_dev);

return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
@@ -1087,7 +1029,7 @@ static int ads1015_runtime_suspend(struct device *dev)

static int ads1015_runtime_resume(struct device *dev)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ads1015_data *data = iio_priv(indio_dev);
int ret;

@@ -1099,43 +1041,11 @@ static int ads1015_runtime_resume(struct device *dev)
}
#endif

-static const struct dev_pm_ops ads1015_pm_ops = {
+const struct dev_pm_ops ads1015_pm_ops = {
SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
ads1015_runtime_resume, NULL)
};
-
-static const struct i2c_device_id ads1015_id[] = {
- {"ads1015", ADS1015},
- {"ads1115", ADS1115},
- {}
-};
-MODULE_DEVICE_TABLE(i2c, ads1015_id);
-
-static const struct of_device_id ads1015_of_match[] = {
- {
- .compatible = "ti,ads1015",
- .data = (void *)ADS1015
- },
- {
- .compatible = "ti,ads1115",
- .data = (void *)ADS1115
- },
- {}
-};
-MODULE_DEVICE_TABLE(of, ads1015_of_match);
-
-static struct i2c_driver ads1015_driver = {
- .driver = {
- .name = ADS1015_DRV_NAME,
- .of_match_table = ads1015_of_match,
- .pm = &ads1015_pm_ops,
- },
- .probe = ads1015_probe,
- .remove = ads1015_remove,
- .id_table = ads1015_id,
-};
-
-module_i2c_driver(ads1015_driver);
+EXPORT_SYMBOL_GPL(ads1015_pm_ops);

MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx>");
MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
diff --git a/drivers/iio/adc/ti-ads1015.h b/drivers/iio/adc/ti-ads1015.h
new file mode 100644
index 000000000000..746f4cdc7637
--- /dev/null
+++ b/drivers/iio/adc/ti-ads1015.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TI_ADS1015_H_
+#define _TI_ADS1015_H_
+
+#define ADS1015_DRV_NAME "ads1015"
+
+#define ADS1015_CONV_REG 0x00
+#define ADS1015_CFG_REG 0x01
+#define ADS1015_LO_THRESH_REG 0x02
+#define ADS1015_HI_THRESH_REG 0x03
+
+#define ADS1015_CFG_COMP_QUE_SHIFT 0
+#define ADS1015_CFG_COMP_LAT_SHIFT 2
+#define ADS1015_CFG_COMP_POL_SHIFT 3
+#define ADS1015_CFG_COMP_MODE_SHIFT 4
+#define ADS1015_CFG_DR_SHIFT 5
+#define ADS1015_CFG_MOD_SHIFT 8
+#define ADS1015_CFG_PGA_SHIFT 9
+#define ADS1015_CFG_MUX_SHIFT 12
+
+#define ADS1015_CFG_COMP_QUE_MASK GENMASK(1, 0)
+#define ADS1015_CFG_COMP_LAT_MASK BIT(2)
+#define ADS1015_CFG_COMP_POL_MASK BIT(3)
+#define ADS1015_CFG_COMP_MODE_MASK BIT(4)
+#define ADS1015_CFG_DR_MASK GENMASK(7, 5)
+#define ADS1015_CFG_MOD_MASK BIT(8)
+#define ADS1015_CFG_PGA_MASK GENMASK(11, 9)
+#define ADS1015_CFG_MUX_MASK GENMASK(14, 12)
+
+/* Comparator queue and disable field */
+#define ADS1015_CFG_COMP_DISABLE 3
+
+/* Comparator polarity field */
+#define ADS1015_CFG_COMP_POL_LOW 0
+#define ADS1015_CFG_COMP_POL_HIGH 1
+
+/* Comparator mode field */
+#define ADS1015_CFG_COMP_MODE_TRAD 0
+#define ADS1015_CFG_COMP_MODE_WINDOW 1
+
+/* device operating modes */
+#define ADS1015_CONTINUOUS 0
+#define ADS1015_SINGLESHOT 1
+
+#define ADS1015_SLEEP_DELAY_MS 2000
+#define ADS1015_DEFAULT_PGA 21
+#define ADS1015_DEFAULT_DATA_RATE 4
+#define ADS1015_DEFAULT_CHAN 0
+
+enum chip_ids {
+ ADS1015,
+ ADS1115,
+};
+
+extern const struct regmap_config ads1015_regmap_config;
+
+int ads1015_core_probe(struct device *dev, struct regmap *regmap,
+ const char *name, int irq, unsigned int chip);
+int ads1015_core_remove(struct device *dev);
+
+extern const struct dev_pm_ops ads1015_pm_ops;
+
+#endif /* _TI_ADS1015_H_ */
diff --git a/drivers/iio/adc/ti-ads1015_i2c.c b/drivers/iio/adc/ti-ads1015_i2c.c
new file mode 100644
index 000000000000..68db9983a37f
--- /dev/null
+++ b/drivers/iio/adc/ti-ads1015_i2c.c
@@ -0,0 +1,80 @@
+/*
+ * ADS1015 Texas Instruments ADC, I2C bits
+ *
+ * Copyright (C) 2018 Georgiana Chelu <georgiana.chelu93@xxxxxxxxx>
+ *
+ * IIO driver for ADS1015 ADC 7-bit I2C slave address:
+ * * 0x48 - ADDR connected to Ground
+ * * 0x49 - ADDR connected to Vdd
+ * * 0x4A - ADDR connected to SDA
+ * * 0x4B - ADDR connected to SCL
+ */
+
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+#include "ti-ads1015.h"
+
+static int ads1015_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct regmap *regmap;
+ const char *name = NULL;
+
+ regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(&client->dev, "failed to allocate i2c register map\n");
+ return PTR_ERR(regmap);
+ }
+
+ if (id)
+ name = id->name;
+
+ return ads1015_core_probe(&client->dev, regmap, name,
+ client->irq, id->driver_data);
+}
+
+static int ads1015_i2c_remove(struct i2c_client *client)
+{
+ return ads1015_core_remove(&client->dev);
+}
+
+static const struct i2c_device_id ads1015_i2c_id[] = {
+ {"ads1015", ADS1015},
+ {"ads1115", ADS1115},
+ {},
+};
+MODULE_DEVICE_TABLE(i2c, ads1015_i2c_id);
+
+static const struct of_device_id ads1015_of_i2c_match[] = {
+ {
+ .compatible = "ti,ads1015",
+ .data = (void *)ADS1015
+ },
+ {
+ .compatible = "ti,ads1115",
+ .data = (void *)ADS1115
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ads1015_of_i2c_match);
+
+static struct i2c_driver ads1015_i2c_driver = {
+ .driver = {
+ .name = ADS1015_DRV_NAME,
+ .of_match_table = of_match_ptr(ads1015_of_i2c_match),
+ .pm = &ads1015_pm_ops,
+ },
+ .probe = ads1015_i2c_probe,
+ .remove = ads1015_i2c_remove,
+ .id_table = ads1015_i2c_id,
+};
+
+module_i2c_driver(ads1015_i2c_driver);
+
+MODULE_AUTHOR("Georgiana Chelu <georgiana.chelu93@xxxxxxxxx>");
+MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver I2C");
+MODULE_LICENSE("GPL v2");
--
2.14.1