2022-07-27 18:15:50

by Potin Lai

Subject: [PATCH v3 2/2] iio: humidity: hdc100x: add manufacturer and device ID check

Add manufacturer and device ID checking during probe, and skip the
checking if chip model not supported.

Supported:
- HDC1000
- HDC1010
- HDC1050
- HDC1080

Not supported:
- HDC1008

Signed-off-by: Potin Lai <[email protected]>
---
drivers/iio/humidity/hdc100x.c | 70 ++++++++++++++++++++++++++++------
1 file changed, 59 insertions(+), 11 deletions(-)

diff --git a/drivers/iio/humidity/hdc100x.c b/drivers/iio/humidity/hdc100x.c
index 0d514818635cb..593a9d3caf229 100644
--- a/drivers/iio/humidity/hdc100x.c
+++ b/drivers/iio/humidity/hdc100x.c
@@ -34,6 +34,23 @@
#define HDC100X_REG_CONFIG_ACQ_MODE BIT(12)
#define HDC100X_REG_CONFIG_HEATER_EN BIT(13)

+#define HDC100X_REG_MFR_ID 0xFE
+#define HDC100X_REG_DEV_ID 0xFF
+
+#define HDC100X_MFR_ID 0x5449
+
+struct hdc100x_chip_data {
+ bool support_mfr_check;
+};
+
+static const struct hdc100x_chip_data hdc100x_chip_data = {
+ .support_mfr_check = true,
+};
+
+static const struct hdc100x_chip_data hdc1008_chip_data = {
+ .support_mfr_check = false,
+};
+
struct hdc100x_data {
struct i2c_client *client;
struct mutex lock;
@@ -351,6 +368,34 @@ static const struct iio_info hdc100x_info = {
.attrs = &hdc100x_attribute_group,
};

+static int hdc100x_read_mfr_id(struct i2c_client *client)
+{
+ return i2c_smbus_read_word_swapped(client, HDC100X_REG_MFR_ID);
+}
+
+static int hdc100x_read_dev_id(struct i2c_client *client)
+{
+ return i2c_smbus_read_word_swapped(client, HDC100X_REG_DEV_ID);
+}
+
+static bool is_valid_hdc100x(struct i2c_client *client)
+{
+ const struct hdc100x_chip_data *data;
+ int mfr_id, dev_id;
+
+ data = device_get_match_data(&client->dev);
+ if (!data->support_mfr_check)
+ return true;
+
+ mfr_id = hdc100x_read_mfr_id(client);
+ dev_id = hdc100x_read_dev_id(client);
+ if (mfr_id == HDC100X_MFR_ID &&
+ (dev_id == 0x1000 || dev_id == 0x1050))
+ return true;
+
+ return false;
+}
+
static int hdc100x_probe(struct i2c_client *client)
{
struct iio_dev *indio_dev;
@@ -361,6 +406,9 @@ static int hdc100x_probe(struct i2c_client *client)
I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
return -EOPNOTSUPP;

+ if (!is_valid_hdc100x(client))
+ return -EINVAL;
+
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
@@ -396,22 +444,22 @@ static int hdc100x_probe(struct i2c_client *client)
}

static const struct i2c_device_id hdc100x_id[] = {
- { "hdc100x", 0 },
- { "hdc1000", 0 },
- { "hdc1008", 0 },
- { "hdc1010", 0 },
- { "hdc1050", 0 },
- { "hdc1080", 0 },
+ { "hdc100X", (kernel_ulong_t)&hdc100x_chip_data },
+ { "hdc1000", (kernel_ulong_t)&hdc100x_chip_data },
+ { "hdc1008", (kernel_ulong_t)&hdc1008_chip_data },
+ { "hdc1010", (kernel_ulong_t)&hdc100x_chip_data },
+ { "hdc1050", (kernel_ulong_t)&hdc100x_chip_data },
+ { "hdc1080", (kernel_ulong_t)&hdc100x_chip_data },
{ }
};
MODULE_DEVICE_TABLE(i2c, hdc100x_id);

static const struct of_device_id hdc100x_dt_ids[] = {
- { .compatible = "ti,hdc1000" },
- { .compatible = "ti,hdc1008" },
- { .compatible = "ti,hdc1010" },
- { .compatible = "ti,hdc1050" },
- { .compatible = "ti,hdc1080" },
+ { .compatible = "ti,hdc1000", .data = &hdc100x_chip_data },
+ { .compatible = "ti,hdc1008", .data = &hdc1008_chip_data },
+ { .compatible = "ti,hdc1010", .data = &hdc100x_chip_data },
+ { .compatible = "ti,hdc1050", .data = &hdc100x_chip_data },
+ { .compatible = "ti,hdc1080", .data = &hdc100x_chip_data },
{ }
};
MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
--
2.31.1

2022-07-27 18:34:32

by Andy Shevchenko

Subject: Re: [PATCH v3 2/2] iio: humidity: hdc100x: add manufacturer and device ID check

On Wed, Jul 27, 2022 at 6:43 PM Potin Lai <[email protected]> wrote:
>
> Add manufacturer and device ID checking during probe, and skip the
> checking if chip model not supported.
>
> Supported:
> - HDC1000
> - HDC1010
> - HDC1050
> - HDC1080
>
> Not supported:
> - HDC1008

Almost there!

...

> +static bool is_valid_hdc100x(struct i2c_client *client)
> +{
> + const struct hdc100x_chip_data *data;
> + int mfr_id, dev_id;

> + data = device_get_match_data(&client->dev);
> + if (!data->support_mfr_check)
> + return true;

Logically this part does belong to ->probe() and doesn't here (too
wide for this specific helper).

> + mfr_id = hdc100x_read_mfr_id(client);
> + dev_id = hdc100x_read_dev_id(client);
> + if (mfr_id == HDC100X_MFR_ID &&
> + (dev_id == 0x1000 || dev_id == 0x1050))
> + return true;
> +
> + return false;
> +}

...

> + if (!is_valid_hdc100x(client))
> + return -EINVAL;

Means here you add

const struct hdc100x_chip_data *data;
struct device *dev = &client->dev;
...
data = device_get_match_data(dev);
if (data->support_mfr_check && !is_valid_hdc100x(client))
return -EINVAL;

(Introducing a temporary variable for struct device pointer might also
help in future to refactor to make code neater.)

--
With Best Regards,
Andy Shevchenko