This allows to share most of this driver for the ltc2496 driver added in
the next commit that is an SPI variant of the ltc2497. Initially I named
the generic part ltc249x, but wild card names are frowned upon, so the
generic part is called ltc2497-core even though it's not obvious that
this is then to be reused for the ltc2496 driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/iio/adc/Makefile | 2 +-
drivers/iio/adc/ltc2497-core.c | 243 +++++++++++++++++++++++++++++++++
drivers/iio/adc/ltc2497.c | 234 ++++---------------------------
drivers/iio/adc/ltc2497.h | 18 +++
4 files changed, 288 insertions(+), 209 deletions(-)
create mode 100644 drivers/iio/adc/ltc2497-core.c
create mode 100644 drivers/iio/adc/ltc2497.h
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index ef9cc485fb67..ee0c8dcfb501 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -47,7 +47,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
obj-$(CONFIG_LTC2471) += ltc2471.o
obj-$(CONFIG_LTC2485) += ltc2485.o
-obj-$(CONFIG_LTC2497) += ltc2497.o
+obj-$(CONFIG_LTC2497) += ltc2497.o ltc2497-core.o
obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX11100) += max11100.o
obj-$(CONFIG_MAX1118) += max1118.o
diff --git a/drivers/iio/adc/ltc2497-core.c b/drivers/iio/adc/ltc2497-core.c
new file mode 100644
index 000000000000..f5f7039caacc
--- /dev/null
+++ b/drivers/iio/adc/ltc2497-core.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ltc2497-core.c - Common code for Analog Devices/Linear Technology
+ * LTC2496 and LTC2497 ADCs
+ *
+ * Copyright (C) 2017 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+
+#include "ltc2497.h"
+
+#define LTC2497_SGL BIT(4)
+#define LTC2497_DIFF 0
+#define LTC2497_SIGN BIT(3)
+
+static int ltc2497core_wait_conv(struct ltc2497core_driverdata *ddata)
+{
+ s64 time_elapsed;
+
+ time_elapsed = ktime_ms_delta(ktime_get(), ddata->time_prev);
+
+ if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
+ /* delay if conversion time not passed
+ * since last read or write
+ */
+ if (msleep_interruptible(
+ LTC2497_CONVERSION_TIME_MS - time_elapsed))
+ return -ERESTARTSYS;
+
+ return 0;
+ }
+
+ if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
+ /* We're in automatic mode -
+ * so the last reading is still not outdated
+ */
+ return 0;
+ }
+
+ return 1;
+}
+
+static int ltc2497core_read(struct ltc2497core_driverdata *ddata, u8 address, int *val)
+{
+ int ret;
+
+ ret = ltc2497core_wait_conv(ddata);
+ if (ret < 0)
+ return ret;
+
+ if (ret || ddata->addr_prev != address) {
+ ret = ddata->result_and_measure(ddata, address, NULL);
+ if (ret < 0)
+ return ret;
+ ddata->addr_prev = address;
+
+ if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
+ return -ERESTARTSYS;
+ }
+
+ ret = ddata->result_and_measure(ddata, address, val);
+ if (ret < 0)
+ return ret;
+
+ ddata->time_prev = ktime_get();
+
+ return ret;
+}
+
+static int ltc2497core_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&indio_dev->mlock);
+ ret = ltc2497core_read(ddata, chan->address, val);
+ mutex_unlock(&indio_dev->mlock);
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = regulator_get_voltage(ddata->ref);
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
+ *val2 = 17;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (_chan), \
+ .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .datasheet_name = (_ds_name), \
+}
+
+#define LTC2497_CHAN_DIFF(_chan, _addr) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
+ .channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
+ .address = (_addr | _chan), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .differential = 1, \
+}
+
+static const struct iio_chan_spec ltc2497core_channel[] = {
+ LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
+ LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
+ LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
+ LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
+ LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
+ LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
+ LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
+ LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
+ LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
+ LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
+ LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
+ LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
+ LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
+ LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
+ LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
+ LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
+ LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
+ LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
+ LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
+};
+
+static const struct iio_info ltc2497core_info = {
+ .read_raw = ltc2497core_read_raw,
+};
+
+int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
+{
+ struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
+ int ret;
+
+ indio_dev->dev.parent = dev;
+ indio_dev->name = dev_name(dev);
+ indio_dev->info = <c2497core_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = ltc2497core_channel;
+ indio_dev->num_channels = ARRAY_SIZE(ltc2497core_channel);
+
+ ret = ddata->result_and_measure(ddata, LTC2497_CONFIG_DEFAULT, NULL);
+ if (ret < 0)
+ return ret;
+
+ ddata->ref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(ddata->ref)) {
+ if (PTR_ERR(ddata->ref) != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get vref regulator: %pe\n",
+ ddata->ref);
+
+ return PTR_ERR(ddata->ref);
+ }
+
+ ret = regulator_enable(ddata->ref);
+ if (ret < 0) {
+ dev_err(dev, "Failed to enable vref regulator: %pe\n",
+ ERR_PTR(ret));
+ return ret;
+ }
+
+ if (dev->platform_data) {
+ struct iio_map *plat_data;
+
+ plat_data = (struct iio_map *)dev->platform_data;
+
+ ret = iio_map_array_register(indio_dev, plat_data);
+ if (ret) {
+ dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
+ goto err_regulator_disable;
+ }
+ }
+
+ ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
+ ddata->time_prev = ktime_get();
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0)
+ goto err_array_unregister;
+
+ return 0;
+
+err_array_unregister:
+ iio_map_array_unregister(indio_dev);
+
+err_regulator_disable:
+ regulator_disable(ddata->ref);
+
+ return ret;
+}
+EXPORT_SYMBOL_NS(ltc2497core_probe, LTC2497);
+
+void ltc2497core_remove(struct iio_dev *indio_dev)
+{
+ struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ iio_map_array_unregister(indio_dev);
+
+ regulator_disable(ddata->ref);
+}
+EXPORT_SYMBOL_NS(ltc2497core_remove, LTC2497);
+
+MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c
index 470406032720..5db63d7c6bc5 100644
--- a/drivers/iio/adc/ltc2497.c
+++ b/drivers/iio/adc/ltc2497.c
@@ -7,27 +7,18 @@
* Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf
*/
-#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
-#include <linux/iio/sysfs.h>
#include <linux/module.h>
#include <linux/of.h>
-#include <linux/regulator/consumer.h>
-#define LTC2497_ENABLE 0xA0
-#define LTC2497_SGL BIT(4)
-#define LTC2497_DIFF 0
-#define LTC2497_SIGN BIT(3)
-#define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE
-#define LTC2497_CONVERSION_TIME_MS 150ULL
+#include "ltc2497.h"
-struct ltc2497_st {
+struct ltc2497_driverdata {
+ /* this must be the first member */
+ struct ltc2497core_driverdata common_ddata;
struct i2c_client *client;
- struct regulator *ref;
- ktime_t time_prev;
- u8 addr_prev;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
@@ -35,232 +26,59 @@ struct ltc2497_st {
__be32 buf ____cacheline_aligned;
};
-static int ltc2497_wait_conv(struct ltc2497_st *st)
+static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,
+ u8 address, int *val)
{
- s64 time_elapsed;
-
- time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev);
-
- if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
- /* delay if conversion time not passed
- * since last read or write
- */
- if (msleep_interruptible(
- LTC2497_CONVERSION_TIME_MS - time_elapsed))
- return -ERESTARTSYS;
-
- return 0;
- }
-
- if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
- /* We're in automatic mode -
- * so the last reading is stil not outdated
- */
- return 0;
- }
-
- return 1;
-}
-
-static int ltc2497_read(struct ltc2497_st *st, u8 address, int *val)
-{
- struct i2c_client *client = st->client;
- int ret;
-
- ret = ltc2497_wait_conv(st);
- if (ret < 0)
- return ret;
-
- if (ret || st->addr_prev != address) {
- ret = i2c_smbus_write_byte(st->client,
- LTC2497_ENABLE | address);
- if (ret < 0)
- return ret;
- st->addr_prev = address;
- if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
- return -ERESTARTSYS;
- }
- ret = i2c_master_recv(client, (char *)&st->buf, 3);
- if (ret < 0) {
- dev_err(&client->dev, "i2c_master_recv failed\n");
- return ret;
- }
- st->time_prev = ktime_get();
-
- /* convert and shift the result,
- * and finally convert from offset binary to signed integer
- */
- *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
-
- return ret;
-}
-
-static int ltc2497_read_raw(struct iio_dev *indio_dev,
- struct iio_chan_spec const *chan,
- int *val, int *val2, long mask)
-{
- struct ltc2497_st *st = iio_priv(indio_dev);
+ struct ltc2497_driverdata *st =
+ container_of(ddata, struct ltc2497_driverdata, common_ddata);
int ret;
- switch (mask) {
- case IIO_CHAN_INFO_RAW:
- mutex_lock(&indio_dev->mlock);
- ret = ltc2497_read(st, chan->address, val);
- mutex_unlock(&indio_dev->mlock);
- if (ret < 0)
- return ret;
-
- return IIO_VAL_INT;
-
- case IIO_CHAN_INFO_SCALE:
- ret = regulator_get_voltage(st->ref);
- if (ret < 0)
+ if (val) {
+ ret = i2c_master_recv(st->client, (char *)&st->buf, 3);
+ if (ret < 0) {
+ dev_err(&st->client->dev, "i2c_master_recv failed\n");
return ret;
+ }
- *val = ret / 1000;
- *val2 = 17;
-
- return IIO_VAL_FRACTIONAL_LOG2;
-
- default:
- return -EINVAL;
+ *val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
}
-}
-#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
- .type = IIO_VOLTAGE, \
- .indexed = 1, \
- .channel = (_chan), \
- .address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
- .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
- .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
- .datasheet_name = (_ds_name), \
-}
-
-#define LTC2497_CHAN_DIFF(_chan, _addr) { \
- .type = IIO_VOLTAGE, \
- .indexed = 1, \
- .channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
- .channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
- .address = (_addr | _chan), \
- .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
- .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
- .differential = 1, \
+ ret = i2c_smbus_write_byte(st->client,
+ LTC2497_ENABLE | address);
+ if (ret)
+ dev_err(&st->client->dev, "i2c transfer failed: %pe\n",
+ ERR_PTR(ret));
+ return ret;
}
-static const struct iio_chan_spec ltc2497_channel[] = {
- LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
- LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
- LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
- LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
- LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
- LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
- LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
- LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
- LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
- LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
- LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
- LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
- LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
- LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
- LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
- LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
- LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
- LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
- LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
-};
-
-static const struct iio_info ltc2497_info = {
- .read_raw = ltc2497_read_raw,
-};
-
static int ltc2497_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
- struct ltc2497_st *st;
- struct iio_map *plat_data;
- int ret;
+ struct ltc2497_driverdata *st;
+ struct device *dev = &client->dev;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_WRITE_BYTE))
return -EOPNOTSUPP;
- indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
st->client = client;
+ st->common_ddata.result_and_measure = ltc2497_result_and_measure;
- indio_dev->dev.parent = &client->dev;
- indio_dev->name = id->name;
- indio_dev->info = <c2497_info;
- indio_dev->modes = INDIO_DIRECT_MODE;
- indio_dev->channels = ltc2497_channel;
- indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel);
-
- st->ref = devm_regulator_get(&client->dev, "vref");
- if (IS_ERR(st->ref))
- return PTR_ERR(st->ref);
-
- ret = regulator_enable(st->ref);
- if (ret < 0)
- return ret;
-
- if (client->dev.platform_data) {
- plat_data = ((struct iio_map *)client->dev.platform_data);
- ret = iio_map_array_register(indio_dev, plat_data);
- if (ret) {
- dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
- goto err_regulator_disable;
- }
- }
-
- ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT);
- if (ret < 0)
- goto err_array_unregister;
-
- st->addr_prev = LTC2497_CONFIG_DEFAULT;
- st->time_prev = ktime_get();
-
- ret = iio_device_register(indio_dev);
- if (ret < 0)
- goto err_array_unregister;
-
- return 0;
-
-err_array_unregister:
- iio_map_array_unregister(indio_dev);
-
-err_regulator_disable:
- regulator_disable(st->ref);
-
- return ret;
+ return ltc2497core_probe(dev, indio_dev);
}
static int ltc2497_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
- struct ltc2497_st *st = iio_priv(indio_dev);
- iio_map_array_unregister(indio_dev);
- iio_device_unregister(indio_dev);
- regulator_disable(st->ref);
+ ltc2497core_remove(indio_dev);
return 0;
}
diff --git a/drivers/iio/adc/ltc2497.h b/drivers/iio/adc/ltc2497.h
new file mode 100644
index 000000000000..d0b42dd6b8ad
--- /dev/null
+++ b/drivers/iio/adc/ltc2497.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#define LTC2497_ENABLE 0xA0
+#define LTC2497_CONFIG_DEFAULT LTC2497_ENABLE
+#define LTC2497_CONVERSION_TIME_MS 150ULL
+
+struct ltc2497core_driverdata {
+ struct regulator *ref;
+ ktime_t time_prev;
+ u8 addr_prev;
+ int (*result_and_measure)(struct ltc2497core_driverdata *ddata,
+ u8 address, int *val);
+};
+
+int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev);
+void ltc2497core_remove(struct iio_dev *indio_dev);
+
+MODULE_IMPORT_NS(LTC2497);
--
2.24.0
