[PATCH v3 0/4] Match data improvements for mcp4725 driver

[PATCH v3 0/4] Match data improvements for mcp4725 driver

[Biju Das]

This patch series aims to add match data improvements for mcp4725 driver.

This patch series is only compile tested.

v2->v3:
 * Added struct mcp4725_chip_info with chan_spec and chip_id variable and
   used that as OF/ID table match data.
 * Added variables use_ext_ref_voltage and dac_reg_offset to struct
   mcp4725_chip_info to handle hw differences between mcp4725 and
   mcp4726.
v1->v2:
 * Update commit description with reason for change.

Biju Das (4):
  iio: dac: mcp4725: Replace variable 'id' from struct mcp4725_data
  iio: dac: mcp4725: Use i2c_get_match_data()
  iio: dac: mcp4725: Add use_ext_ref_voltage to struct mcp4725_chip_info
  iio: dac: mcp4725: Add dac_reg_offset to struct mcp4725_chip_info

 drivers/iio/dac/mcp4725.c | 42 ++++++++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 14 deletions(-)

-- 
2.25.1

[PATCH v3 1/4] iio: dac: mcp4725: Replace variable 'id' from struct mcp4725_data

[Biju Das]

Replace the variable 'id' from struct mcp4725_data with local variable
chip_id in probe() as the id variable is not used elsewhere in the
driver.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * No change.
v1->v2:
 * Update commit description with reason for change.
---
 drivers/iio/dac/mcp4725.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index f4a3124d29f2..33a61f65bc25 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -32,7 +32,6 @@
 
 struct mcp4725_data {
 	struct i2c_client *client;
-	int id;
 	unsigned ref_mode;
 	bool vref_buffered;
 	u16 dac_value;
@@ -387,6 +386,7 @@ static int mcp4725_probe(struct i2c_client *client)
 	struct mcp4725_data *data;
 	struct iio_dev *indio_dev;
 	struct mcp4725_platform_data *pdata, pdata_dt;
+	int chip_id;
 	u8 inbuf[4];
 	u8 pd;
 	u8 ref;
@@ -399,9 +399,9 @@ static int mcp4725_probe(struct i2c_client *client)
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
 	if (dev_fwnode(&client->dev))
-		data->id = (uintptr_t)device_get_match_data(&client->dev);
+		chip_id = (uintptr_t)device_get_match_data(&client->dev);
 	else
-		data->id = id->driver_data;
+		chip_id = id->driver_data;
 	pdata = dev_get_platdata(&client->dev);
 
 	if (!pdata) {
@@ -414,7 +414,7 @@ static int mcp4725_probe(struct i2c_client *client)
 		pdata = &pdata_dt;
 	}
 
-	if (data->id == MCP4725 && pdata->use_vref) {
+	if (chip_id == MCP4725 && pdata->use_vref) {
 		dev_err(&client->dev,
 			"external reference is unavailable on MCP4725");
 		return -EINVAL;
@@ -455,12 +455,12 @@ static int mcp4725_probe(struct i2c_client *client)
 
 	indio_dev->name = id->name;
 	indio_dev->info = &mcp4725_info;
-	indio_dev->channels = &mcp472x_channel[id->driver_data];
+	indio_dev->channels = &mcp472x_channel[chip_id];
 	indio_dev->num_channels = 1;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	/* read current DAC value and settings */
-	err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
+	err = i2c_master_recv(client, inbuf, chip_id == MCP4725 ? 3 : 4);
 
 	if (err < 0) {
 		dev_err(&client->dev, "failed to read DAC value");
@@ -470,10 +470,10 @@ static int mcp4725_probe(struct i2c_client *client)
 	data->powerdown = pd > 0;
 	data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
 	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
-	if (data->id == MCP4726)
+	if (chip_id == MCP4726)
 		ref = (inbuf[3] >> 3) & 0x3;
 
-	if (data->id == MCP4726 && ref != data->ref_mode) {
+	if (chip_id == MCP4726 && ref != data->ref_mode) {
 		dev_info(&client->dev,
 			"voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
 			data->ref_mode, ref, data->ref_mode);
-- 
2.25.1

[PATCH v3 2/4] iio: dac: mcp4725: Use i2c_get_match_data()

[Biju Das]

Add struct mcp4725_chip_info with chan_spec and chip_id variable.
After this simplify probe() by replacing device_get_match_data() and id
lookup for retrieving match data by i2c_get_match_data() by converting
enum->pointer for data in the match table.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Added struct mcp4725_chip_info with chan_spec and chip_id variable and
   used that as OF/ID table match data.
v2:
 * New patch
---
 drivers/iio/dac/mcp4725.c | 40 +++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index 33a61f65bc25..fe8981ec7923 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -30,6 +30,11 @@
 #define MCP472X_REF_VREF_UNBUFFERED	0x02
 #define MCP472X_REF_VREF_BUFFERED	0x03
 
+struct mcp4725_chip_info {
+	const struct iio_chan_spec *chan_spec;
+	unsigned int chip_id;
+};
+
 struct mcp4725_data {
 	struct i2c_client *client;
 	unsigned ref_mode;
@@ -383,10 +388,10 @@ static int mcp4725_probe_dt(struct device *dev,
 static int mcp4725_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
+	const struct mcp4725_chip_info *info;
 	struct mcp4725_data *data;
 	struct iio_dev *indio_dev;
 	struct mcp4725_platform_data *pdata, pdata_dt;
-	int chip_id;
 	u8 inbuf[4];
 	u8 pd;
 	u8 ref;
@@ -398,10 +403,7 @@ static int mcp4725_probe(struct i2c_client *client)
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
-	if (dev_fwnode(&client->dev))
-		chip_id = (uintptr_t)device_get_match_data(&client->dev);
-	else
-		chip_id = id->driver_data;
+	info = i2c_get_match_data(client);
 	pdata = dev_get_platdata(&client->dev);
 
 	if (!pdata) {
@@ -414,7 +416,7 @@ static int mcp4725_probe(struct i2c_client *client)
 		pdata = &pdata_dt;
 	}
 
-	if (chip_id == MCP4725 && pdata->use_vref) {
+	if (info->chip_id == MCP4725 && pdata->use_vref) {
 		dev_err(&client->dev,
 			"external reference is unavailable on MCP4725");
 		return -EINVAL;
@@ -455,12 +457,12 @@ static int mcp4725_probe(struct i2c_client *client)
 
 	indio_dev->name = id->name;
 	indio_dev->info = &mcp4725_info;
-	indio_dev->channels = &mcp472x_channel[chip_id];
+	indio_dev->channels = info->chan_spec;
 	indio_dev->num_channels = 1;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	/* read current DAC value and settings */
-	err = i2c_master_recv(client, inbuf, chip_id == MCP4725 ? 3 : 4);
+	err = i2c_master_recv(client, inbuf, info->chip_id == MCP4725 ? 3 : 4);
 
 	if (err < 0) {
 		dev_err(&client->dev, "failed to read DAC value");
@@ -470,10 +472,10 @@ static int mcp4725_probe(struct i2c_client *client)
 	data->powerdown = pd > 0;
 	data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
 	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
-	if (chip_id == MCP4726)
+	if (info->chip_id == MCP4726)
 		ref = (inbuf[3] >> 3) & 0x3;
 
-	if (chip_id == MCP4726 && ref != data->ref_mode) {
+	if (info->chip_id == MCP4726 && ref != data->ref_mode) {
 		dev_info(&client->dev,
 			"voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
 			data->ref_mode, ref, data->ref_mode);
@@ -510,9 +512,19 @@ static void mcp4725_remove(struct i2c_client *client)
 	regulator_disable(data->vdd_reg);
 }
 
+static const struct mcp4725_chip_info mcp4725 = {
+	.chan_spec = &mcp472x_channel[MCP4725],
+	.chip_id = MCP4725,
+};
+
+static const struct mcp4725_chip_info mcp4726 = {
+	.chan_spec = &mcp472x_channel[MCP4726],
+	.chip_id = MCP4726,
+};
+
 static const struct i2c_device_id mcp4725_id[] = {
-	{ "mcp4725", MCP4725 },
-	{ "mcp4726", MCP4726 },
+	{ "mcp4725", (kernel_ulong_t)&mcp4725 },
+	{ "mcp4726", (kernel_ulong_t)&mcp4726 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, mcp4725_id);
@@ -520,11 +532,11 @@ MODULE_DEVICE_TABLE(i2c, mcp4725_id);
 static const struct of_device_id mcp4725_of_match[] = {
 	{
 		.compatible = "microchip,mcp4725",
-		.data = (void *)MCP4725
+		.data = &mcp4725
 	},
 	{
 		.compatible = "microchip,mcp4726",
-		.data = (void *)MCP4726
+		.data = &mcp4726
 	},
 	{ }
 };
-- 
2.25.1

[PATCH v3 3/4] iio: dac: mcp4725: Add use_ext_ref_voltage to struct mcp4725_chip_info

[Biju Das]

The MCP4725 has external voltage reference compared MCP4725 which
has reference embeedded in eeprom. Add use_ext_ref_voltage variable
to struct mcp4725_chip_info to handle this difference.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v3:
 * New patch
---
 drivers/iio/dac/mcp4725.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index fe8981ec7923..9cbea6f223e4 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -33,6 +33,7 @@
 struct mcp4725_chip_info {
 	const struct iio_chan_spec *chan_spec;
 	unsigned int chip_id;
+	bool use_ext_ref_voltage;
 };
 
 struct mcp4725_data {
@@ -416,7 +417,7 @@ static int mcp4725_probe(struct i2c_client *client)
 		pdata = &pdata_dt;
 	}
 
-	if (info->chip_id == MCP4725 && pdata->use_vref) {
+	if (info->use_ext_ref_voltage && pdata->use_vref) {
 		dev_err(&client->dev,
 			"external reference is unavailable on MCP4725");
 		return -EINVAL;
@@ -472,10 +473,10 @@ static int mcp4725_probe(struct i2c_client *client)
 	data->powerdown = pd > 0;
 	data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
 	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
-	if (info->chip_id == MCP4726)
+	if (!info->use_ext_ref_voltage)
 		ref = (inbuf[3] >> 3) & 0x3;
 
-	if (info->chip_id == MCP4726 && ref != data->ref_mode) {
+	if (!info->use_ext_ref_voltage && ref != data->ref_mode) {
 		dev_info(&client->dev,
 			"voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
 			data->ref_mode, ref, data->ref_mode);
@@ -515,6 +516,7 @@ static void mcp4725_remove(struct i2c_client *client)
 static const struct mcp4725_chip_info mcp4725 = {
 	.chan_spec = &mcp472x_channel[MCP4725],
 	.chip_id = MCP4725,
+	.use_ext_ref_voltage = true,
 };
 
 static const struct mcp4725_chip_info mcp4726 = {
-- 
2.25.1

[PATCH v3 4/4] iio: dac: mcp4725: Add dac_reg_offset to struct mcp4725_chip_info

[Biju Das]

The MCP4725 has a register offset '3' for reading DAC value compared to
'4' for MCP4726. Add dac_reg_offset variable to struct mcp4725_chip_info
to handle this difference.

Drop chip_id from struct mcp4725_chip_info as it is unused.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v3:
 * New patch.
---
 drivers/iio/dac/mcp4725.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index 9cbea6f223e4..25bb1c0490af 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -32,7 +32,7 @@
 
 struct mcp4725_chip_info {
 	const struct iio_chan_spec *chan_spec;
-	unsigned int chip_id;
+	u8 dac_reg_offset;
 	bool use_ext_ref_voltage;
 };
 
@@ -463,7 +463,7 @@ static int mcp4725_probe(struct i2c_client *client)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 
 	/* read current DAC value and settings */
-	err = i2c_master_recv(client, inbuf, info->chip_id == MCP4725 ? 3 : 4);
+	err = i2c_master_recv(client, inbuf, info->dac_reg_offset);
 
 	if (err < 0) {
 		dev_err(&client->dev, "failed to read DAC value");
@@ -515,13 +515,13 @@ static void mcp4725_remove(struct i2c_client *client)
 
 static const struct mcp4725_chip_info mcp4725 = {
 	.chan_spec = &mcp472x_channel[MCP4725],
-	.chip_id = MCP4725,
+	.dac_reg_offset = 3,
 	.use_ext_ref_voltage = true,
 };
 
 static const struct mcp4725_chip_info mcp4726 = {
 	.chan_spec = &mcp472x_channel[MCP4726],
-	.chip_id = MCP4726,
+	.dac_reg_offset = 4,
 };
 
 static const struct i2c_device_id mcp4725_id[] = {
-- 
2.25.1

Re: [PATCH v3 0/4] Match data improvements for mcp4725 driver

[Jonathan Cameron]

On Sun,  3 Sep 2023 12:55:44 +0100
Biju Das <biju.das.jz@bp.renesas.com> wrote:

> This patch series aims to add match data improvements for mcp4725 driver.
> 
> This patch series is only compile tested.
> 
> v2->v3:
>  * Added struct mcp4725_chip_info with chan_spec and chip_id variable and
>    used that as OF/ID table match data.
>  * Added variables use_ext_ref_voltage and dac_reg_offset to struct
>    mcp4725_chip_info to handle hw differences between mcp4725 and
>    mcp4726.
> v1->v2:
>  * Update commit description with reason for change.
> 
> Biju Das (4):
>   iio: dac: mcp4725: Replace variable 'id' from struct mcp4725_data
>   iio: dac: mcp4725: Use i2c_get_match_data()
>   iio: dac: mcp4725: Add use_ext_ref_voltage to struct mcp4725_chip_info
>   iio: dac: mcp4725: Add dac_reg_offset to struct mcp4725_chip_info
> 
>  drivers/iio/dac/mcp4725.c | 42 ++++++++++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 14 deletions(-)
> 

I've applied this, but still plenty of time for more comments as I'll only
be pushing it out as a non rebasing tree after rc1.

Thanks,

Jonathan