Re: [PATCH v2 3/5] iio: accel: kionix-kx022a: Refactor driver and add chip_info structure

From: Matti Vaittinen
Date: Fri Apr 21 2023 - 02:20:11 EST


Hi Mehdi,

Thanks for working on this driver :) Much appreciated!

On 4/20/23 23:22, Mehdi Djait wrote:
Refactor the kx022a driver implementation to make it more generic and
extensible.
Introduce an i2c_device_id table.
Add the chip_info structure to the driver's private data to hold all
the device specific infos.

Signed-off-by: Mehdi Djait <mehdi.djait.k@xxxxxxxxx>
---
v2:
- mentioned the introduction of the i2c_device_id table in the commit

Maybe adding the i2c_device_id table could be done in a separate patch with a Fixes tag? That would help backporting (and I think changes like this are worth it).

- get i2c_/spi_get_device_id only with device get match fails
- removed the generic KX_define
- removed the kx022a_device_type enum
- added comments for the chip_info struct elements
- fixed errors pointed out by the kernel test robot

drivers/iio/accel/kionix-kx022a-i2c.c | 20 ++++-
drivers/iio/accel/kionix-kx022a-spi.c | 21 ++++--
drivers/iio/accel/kionix-kx022a.c | 102 ++++++++++++++++----------
drivers/iio/accel/kionix-kx022a.h | 54 +++++++++++++-
4 files changed, 146 insertions(+), 51 deletions(-)

diff --git a/drivers/iio/accel/kionix-kx022a-i2c.c b/drivers/iio/accel/kionix-kx022a-i2c.c
index e6fd02d931b6..ce299d0446f7 100644
--- a/drivers/iio/accel/kionix-kx022a-i2c.c
+++ b/drivers/iio/accel/kionix-kx022a-i2c.c
@@ -15,6 +15,7 @@
static int kx022a_i2c_probe(struct i2c_client *i2c)
{
struct device *dev = &i2c->dev;
+ const struct kx022a_chip_info *chip_info;
struct regmap *regmap;
if (!i2c->irq) {
@@ -22,16 +23,28 @@ static int kx022a_i2c_probe(struct i2c_client *i2c)
return -EINVAL;
}
- regmap = devm_regmap_init_i2c(i2c, &kx022a_regmap);
+ chip_info = device_get_match_data(&i2c->dev);
+ if (!chip_info) {
+ const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
+ chip_info = (const struct kx022a_chip_info *)id->driver_data;
+ }
+
+ regmap = devm_regmap_init_i2c(i2c, chip_info->regmap_config);
if (IS_ERR(regmap))
return dev_err_probe(dev, PTR_ERR(regmap),
"Failed to initialize Regmap\n");
- return kx022a_probe_internal(dev);
+ return kx022a_probe_internal(dev, chip_info);
}
+static const struct i2c_device_id kx022a_i2c_id[] = {
+ { .name = "kx022a", .driver_data = (kernel_ulong_t)&kx022a_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, kx022a_i2c_id);
+
static const struct of_device_id kx022a_of_match[] = {
- { .compatible = "kionix,kx022a", },
+ { .compatible = "kionix,kx022a", .data = &kx022a_chip_info },
{ }
};
MODULE_DEVICE_TABLE(of, kx022a_of_match);
@@ -42,6 +55,7 @@ static struct i2c_driver kx022a_i2c_driver = {
.of_match_table = kx022a_of_match,
},
.probe_new = kx022a_i2c_probe,
+ .id_table = kx022a_i2c_id,
};
module_i2c_driver(kx022a_i2c_driver);
diff --git a/drivers/iio/accel/kionix-kx022a-spi.c b/drivers/iio/accel/kionix-kx022a-spi.c
index 9cd047f7b346..7bc81588e40e 100644
--- a/drivers/iio/accel/kionix-kx022a-spi.c
+++ b/drivers/iio/accel/kionix-kx022a-spi.c
@@ -15,6 +15,7 @@
static int kx022a_spi_probe(struct spi_device *spi)
{
struct device *dev = &spi->dev;
+ const struct kx022a_chip_info *chip_info;
struct regmap *regmap;
if (!spi->irq) {
@@ -22,22 +23,28 @@ static int kx022a_spi_probe(struct spi_device *spi)
return -EINVAL;
}
- regmap = devm_regmap_init_spi(spi, &kx022a_regmap);
+ chip_info = device_get_match_data(&spi->dev);
+ if (!chip_info) {
+ const struct spi_device_id *id = spi_get_device_id(spi);
+ chip_info = (const struct kx022a_chip_info *)id->driver_data;
+ }
+
+ regmap = devm_regmap_init_spi(spi, chip_info->regmap_config);
if (IS_ERR(regmap))
return dev_err_probe(dev, PTR_ERR(regmap),
"Failed to initialize Regmap\n");
- return kx022a_probe_internal(dev);
+ return kx022a_probe_internal(dev, chip_info);
}
-static const struct spi_device_id kx022a_id[] = {
- { "kx022a" },
+static const struct spi_device_id kx022a_spi_id[] = {

Did you have a reason to change the struct name? Please, keep the original name if there is no reason to change, it helps decreasing the size of the patch...

+ { .name = "kx022a", .driver_data = (kernel_ulong_t)&kx022a_chip_info },
{ }
};
-MODULE_DEVICE_TABLE(spi, kx022a_id);
+MODULE_DEVICE_TABLE(spi, kx022a_spi_id);

...this would not need to be changed if original name was kept...

static const struct of_device_id kx022a_of_match[] = {
- { .compatible = "kionix,kx022a", },
+ { .compatible = "kionix,kx022a", .data = &kx022a_chip_info },
{ }
};
MODULE_DEVICE_TABLE(of, kx022a_of_match);
@@ -48,7 +55,7 @@ static struct spi_driver kx022a_spi_driver = {
.of_match_table = kx022a_of_match,
},
.probe = kx022a_spi_probe,
- .id_table = kx022a_id,
+ .id_table = kx022a_spi_id,

...and this neither.

};
module_spi_driver(kx022a_spi_driver);
diff --git a/drivers/iio/accel/kionix-kx022a.c b/drivers/iio/accel/kionix-kx022a.c
index 70530005cad3..7f9a2c29790b 100644
--- a/drivers/iio/accel/kionix-kx022a.c
+++ b/drivers/iio/accel/kionix-kx022a.c
@@ -48,7 +48,7 @@ enum {
KX022A_STATE_FIFO,
};
-/* Regmap configs */
+/* kx022a Regmap configs */
static const struct regmap_range kx022a_volatile_ranges[] = {
{
.range_min = KX022A_REG_XHP_L,
@@ -138,7 +138,7 @@ static const struct regmap_access_table kx022a_nir_regs = {
.n_yes_ranges = ARRAY_SIZE(kx022a_noinc_read_ranges),
};
-const struct regmap_config kx022a_regmap = {
+static const struct regmap_config kx022a_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.volatile_table = &kx022a_volatile_regs,
@@ -149,7 +149,6 @@ const struct regmap_config kx022a_regmap = {
.max_register = KX022A_MAX_REGISTER,
.cache_type = REGCACHE_RBTREE,
};
-EXPORT_SYMBOL_NS_GPL(kx022a_regmap, IIO_KX022A);
struct kx022a_data {
struct regmap *regmap;
@@ -208,7 +207,7 @@ static const struct iio_chan_spec_ext_info kx022a_ext_info[] = {
{ }
};

Does this compile? Shouldn't the chip_info be added in the struct kx022a_data?

-#define KX022A_ACCEL_CHAN(axis, index) \
+#define KX022A_ACCEL_CHAN(axis, reg, index) \
{ \
.type = IIO_ACCEL, \
.modified = 1, \
@@ -220,7 +219,7 @@ static const struct iio_chan_spec_ext_info kx022a_ext_info[] = {
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.ext_info = kx022a_ext_info, \
- .address = KX022A_REG_##axis##OUT_L, \
+ .address = reg, \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
@@ -231,9 +230,9 @@ static const struct iio_chan_spec_ext_info kx022a_ext_info[] = {
}
static const struct iio_chan_spec kx022a_channels[] = {
- KX022A_ACCEL_CHAN(X, 0),
- KX022A_ACCEL_CHAN(Y, 1),
- KX022A_ACCEL_CHAN(Z, 2),
+ KX022A_ACCEL_CHAN(X, KX022A_REG_XOUT_L, 0),
+ KX022A_ACCEL_CHAN(Y, KX022A_REG_YOUT_L, 1),
+ KX022A_ACCEL_CHAN(Z, KX022A_REG_ZOUT_L, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
@@ -332,10 +331,10 @@ static int kx022a_turn_on_off_unlocked(struct kx022a_data *data, bool on)
int ret;
if (on)
- ret = regmap_set_bits(data->regmap, KX022A_REG_CNTL,
+ ret = regmap_set_bits(data->regmap, data->chip_info->cntl,
KX022A_MASK_PC1);

Hm, do you have the "chip_info" member added in kx022a_data? I didn't spot it from this patch.

Yours,
-- Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

~~ When things go utterly wrong vim users can always type :help! ~~