iio: adc: ltc2497: split protocol independent part in a separate module
authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Mon, 9 Dec 2019 20:32:47 +0000 (21:32 +0100)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Sun, 15 Dec 2019 12:15:19 +0000 (12:15 +0000)
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@pengutronix.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
drivers/iio/adc/Makefile
drivers/iio/adc/ltc2497-core.c [new file with mode: 0644]
drivers/iio/adc/ltc2497.c
drivers/iio/adc/ltc2497.h [new file with mode: 0644]

index bf8354c..5f8d7ac 100644 (file)
@@ -51,7 +51,7 @@ 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 (file)
index 0000000..f5f7039
--- /dev/null
@@ -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 = &ltc2497core_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");
index 4704060..5db63d7 100644 (file)
@@ -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 = &ltc2497_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 (file)
index 0000000..d0b42dd
--- /dev/null
@@ -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);