iio: accel: bma220: add i2c module

Add the bma220_i2c module.

Note that this kernel module transparently shifts all register addresses
1 bit to the left, so all functions will operate based on the SPI memory
map.

Signed-off-by: Petre Rodan <petre.rodan@subdimension.ro>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 988fe4b1f9a52c2e671ea30d8590f25ee1685ac7..76911278fb217bd3e429c427b873fb7eae26420e 100644 (file)
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -218,10 +218,11 @@ config BMA180
 
 config BMA220
        tristate "Bosch BMA220 3-Axis Accelerometer Driver"
-       depends on SPI
+       depends on I2C || SPI
        select REGMAP
        select IIO_BUFFER
        select IIO_TRIGGERED_BUFFER
+       select BMA220_I2C if I2C
        select BMA220_SPI if SPI
        help
          Say yes here to add support for the Bosch BMA220 triaxial
@@ -229,7 +230,13 @@ config BMA220
 
          To compile this driver as a module, choose M here: the
          module will be called bma220_core and you will also get
-         bma220_spi if SPI is enabled.
+         bma220_i2c if I2C is enabled and bma220_spi if SPI is
+         enabled.
+
+config BMA220_I2C
+       tristate
+       select REGMAP_I2C
+       depends on BMA220
 
 config BMA220_SPI
        tristate

diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 56a9f848f7f913633bc2a628c1ac5c9190774b9d..fa440a85928398fee927081f605595ba9fbc4ad9 100644 (file)
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_ADXL380_I2C) += adxl380_i2c.o
 obj-$(CONFIG_ADXL380_SPI) += adxl380_spi.o
 obj-$(CONFIG_BMA180) += bma180.o
 obj-$(CONFIG_BMA220) += bma220_core.o
+obj-$(CONFIG_BMA220_I2C) += bma220_i2c.o
 obj-$(CONFIG_BMA220_SPI) += bma220_spi.o
 obj-$(CONFIG_BMA400) += bma400_core.o
 obj-$(CONFIG_BMA400_I2C) += bma400_i2c.o

diff --git a/drivers/iio/accel/bma220.h b/drivers/iio/accel/bma220.h
index 695f491bc5a03008f26fe8602ba633456159fb1d..e53ca63de54b4e81df0908b11d0fb7f03a86dbdc 100644 (file)
--- a/drivers/iio/accel/bma220.h
+++ b/drivers/iio/accel/bma220.h
@@ -13,6 +13,7 @@
 
 struct device;
 
+extern const struct regmap_config bma220_i2c_regmap_config;
 extern const struct regmap_config bma220_spi_regmap_config;
 extern const struct dev_pm_ops bma220_pm_ops;
 

diff --git a/drivers/iio/accel/bma220_core.c b/drivers/iio/accel/bma220_core.c
index 404fea26e3f7271d28151b6a2087a19d3cea9fb1..050827bfb9e67e9fe386ebb99c831cb5ec02f586 100644 (file)
--- a/drivers/iio/accel/bma220_core.c
+++ b/drivers/iio/accel/bma220_core.c
@@ -173,6 +173,24 @@ const struct regmap_config bma220_spi_regmap_config = {
 };
 EXPORT_SYMBOL_NS_GPL(bma220_spi_regmap_config, "IIO_BOSCH_BMA220");
 
+/*
+ * Based on the datasheet the memory map differs between the SPI and the I2C
+ * implementations. I2C register addresses are simply shifted to the left
+ * by 1 bit yet the register size remains unchanged.
+ * This driver employs the SPI memory map to correlate register names to
+ * addresses regardless of the bus type.
+ */
+
+const struct regmap_config bma220_i2c_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .reg_shift = -1,
+       .max_register = BMA220_REG_SOFTRESET,
+       .cache_type = REGCACHE_NONE,
+       .writeable_reg = bma220_is_writable_reg,
+};
+EXPORT_SYMBOL_NS_GPL(bma220_i2c_regmap_config, "IIO_BOSCH_BMA220");
+
 static irqreturn_t bma220_trigger_handler(int irq, void *p)
 {
        int ret;

diff --git a/drivers/iio/accel/bma220_i2c.c b/drivers/iio/accel/bma220_i2c.c
new file mode 100644 (file)
index 0000000..5dc7c38
--- /dev/null
+++ b/drivers/iio/accel/bma220_i2c.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Bosch triaxial acceleration sensor
+ *
+ * Copyright (c) 2025 Petre Rodan <petre.rodan@subdimension.ro>
+ *
+ * Datasheet: https://media.digikey.com/pdf/Data%20Sheets/Bosch/BMA220.pdf
+ * I2C address is either 0x0b or 0x0a depending on CSB (pin 10)
+ */
+
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include "bma220.h"
+
+static int bma220_i2c_probe(struct i2c_client *client)
+{
+       struct regmap *regmap;
+
+       regmap = devm_regmap_init_i2c(client, &bma220_i2c_regmap_config);
+       if (IS_ERR(regmap))
+               return dev_err_probe(&client->dev, PTR_ERR(regmap),
+                                    "failed to create regmap\n");
+
+       return bma220_common_probe(&client->dev, regmap, client->irq);
+}
+
+static const struct of_device_id bma220_i2c_match[] = {
+       { .compatible = "bosch,bma220" },
+       { }
+};
+MODULE_DEVICE_TABLE(of, bma220_i2c_match);
+
+static const struct i2c_device_id bma220_i2c_id[] = {
+       { "bma220" },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, bma220_i2c_id);
+
+static struct i2c_driver bma220_i2c_driver = {
+       .driver = {
+               .name = "bma220_i2c",
+               .pm = pm_sleep_ptr(&bma220_pm_ops),
+               .of_match_table = bma220_i2c_match,
+       },
+       .probe = bma220_i2c_probe,
+       .id_table = bma220_i2c_id,
+};
+module_i2c_driver(bma220_i2c_driver);
+
+MODULE_AUTHOR("Petre Rodan <petre.rodan@subdimension.ro>");
+MODULE_DESCRIPTION("Bosch triaxial acceleration sensor i2c driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_BOSCH_BMA220");