diff mbox series

[3/3] iio: accel: st_accel: Add support for Silan SC7A20

Message ID 20220130034441.15474-4-samuel@sholland.org (mailing list archive)
State Changes Requested
Headers show
Series iio: Silan SC7A20 accelerometer support | expand

Commit Message

Samuel Holland Jan. 30, 2022, 3:44 a.m. UTC
This chip appears to be a clone of the LIS2DH. The new description is a
copy of the LIS2DH's description with a different WAI value.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 drivers/iio/accel/st_accel.h      |  2 +
 drivers/iio/accel/st_accel_core.c | 79 +++++++++++++++++++++++++++++++
 drivers/iio/accel/st_accel_i2c.c  |  5 ++
 3 files changed, 86 insertions(+)

Comments

Jonathan Cameron Jan. 30, 2022, 2:10 p.m. UTC | #1
On Sat, 29 Jan 2022 21:44:41 -0600
Samuel Holland <samuel@sholland.org> wrote:

> This chip appears to be a clone of the LIS2DH. The new description is a
> copy of the LIS2DH's description with a different WAI value.
> 
> Signed-off-by: Samuel Holland <samuel@sholland.org>
Hi Samuel,

This is nasty as 0x11 is a valid who am I for an LIS3DHH which is a very
different device.

One request inline for a bit more info in the code about what this device
is etc.  I've found a Chinese data sheet on one of the datasheet aggregator
sites.

If you know of a stable location to add a
Datasheet:
tag to this patch that would also be helpful.

Thanks,

Jonathan

> ---
> 
>  drivers/iio/accel/st_accel.h      |  2 +
>  drivers/iio/accel/st_accel_core.c | 79 +++++++++++++++++++++++++++++++
>  drivers/iio/accel/st_accel_i2c.c  |  5 ++
>  3 files changed, 86 insertions(+)
> 
> diff --git a/drivers/iio/accel/st_accel.h b/drivers/iio/accel/st_accel.h
> index 8750dea56fcb..00e056c21bfc 100644
> --- a/drivers/iio/accel/st_accel.h
> +++ b/drivers/iio/accel/st_accel.h
> @@ -36,6 +36,7 @@ enum st_accel_type {
>  	LIS3DHH,
>  	LIS2DE12,
>  	LIS2HH12,
> +	SC7A20,
>  	ST_ACCEL_MAX,
>  };
>  
> @@ -61,6 +62,7 @@ enum st_accel_type {
>  #define LIS3DE_ACCEL_DEV_NAME		"lis3de"
>  #define LIS2DE12_ACCEL_DEV_NAME		"lis2de12"
>  #define LIS2HH12_ACCEL_DEV_NAME		"lis2hh12"
> +#define SC7A20_ACCEL_DEV_NAME		"sc7a20"
>  
>  #ifdef CONFIG_IIO_BUFFER
>  int st_accel_allocate_ring(struct iio_dev *indio_dev);
> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
> index 31ea19d0ba71..d9aa0ff1922b 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -1087,6 +1087,85 @@ static const struct st_sensor_settings st_accel_sensors_settings[] = {
>  		.multi_read_bit = true,
>  		.bootime = 2,
>  	},
> +	{

Please add a comment here about the fact it seems to be a clone of the LIS2DH
despite the wrong WAI.

It's worth noting that a good part of the maintenance of this driver is
done by ST employees who are probably less than happy with seeing
a clone (with bugs) supported.  So support is likely to be somewhat best
effort / not going to deliberately break support for this part but no
means to test it. Hopefully we'll remember to cc you to test anything new added to
the driver.  Clones aren't always perfect!

Jonathan

> +		.wai = 0x11,
> +		.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
> +		.sensors_supported = {
> +			[0] = SC7A20_ACCEL_DEV_NAME,
> +		},
> +		.ch = (struct iio_chan_spec *)st_accel_12bit_channels,
> +		.odr = {
> +			.addr = 0x20,
> +			.mask = 0xf0,
> +			.odr_avl = {
> +				{ .hz = 1, .value = 0x01, },
> +				{ .hz = 10, .value = 0x02, },
> +				{ .hz = 25, .value = 0x03, },
> +				{ .hz = 50, .value = 0x04, },
> +				{ .hz = 100, .value = 0x05, },
> +				{ .hz = 200, .value = 0x06, },
> +				{ .hz = 400, .value = 0x07, },
> +				{ .hz = 1600, .value = 0x08, },
> +			},
> +		},
> +		.pw = {
> +			.addr = 0x20,
> +			.mask = 0xf0,
> +			.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
> +		},
> +		.enable_axis = {
> +			.addr = ST_SENSORS_DEFAULT_AXIS_ADDR,
> +			.mask = ST_SENSORS_DEFAULT_AXIS_MASK,
> +		},
> +		.fs = {
> +			.addr = 0x23,
> +			.mask = 0x30,
> +			.fs_avl = {
> +				[0] = {
> +					.num = ST_ACCEL_FS_AVL_2G,
> +					.value = 0x00,
> +					.gain = IIO_G_TO_M_S_2(1000),
> +				},
> +				[1] = {
> +					.num = ST_ACCEL_FS_AVL_4G,
> +					.value = 0x01,
> +					.gain = IIO_G_TO_M_S_2(2000),
> +				},
> +				[2] = {
> +					.num = ST_ACCEL_FS_AVL_8G,
> +					.value = 0x02,
> +					.gain = IIO_G_TO_M_S_2(4000),
> +				},
> +				[3] = {
> +					.num = ST_ACCEL_FS_AVL_16G,
> +					.value = 0x03,
> +					.gain = IIO_G_TO_M_S_2(12000),
> +				},
> +			},
> +		},
> +		.bdu = {
> +			.addr = 0x23,
> +			.mask = 0x80,
> +		},
> +		.drdy_irq = {
> +			.int1 = {
> +				.addr = 0x22,
> +				.mask = 0x10,
> +			},
> +			.addr_ihl = 0x25,
> +			.mask_ihl = 0x02,
> +			.stat_drdy = {
> +				.addr = ST_SENSORS_DEFAULT_STAT_ADDR,
> +				.mask = 0x07,
> +			},
> +		},
> +		.sim = {
> +			.addr = 0x23,
> +			.value = BIT(0),
> +		},
> +		.multi_read_bit = true,
> +		.bootime = 2,
> +	},
>  };
>  
>  /* Default accel DRDY is available on INT1 pin */
> diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
> index c0ce78eebad9..7f5888570e87 100644
> --- a/drivers/iio/accel/st_accel_i2c.c
> +++ b/drivers/iio/accel/st_accel_i2c.c
> @@ -107,6 +107,10 @@ static const struct of_device_id st_accel_of_match[] = {
>  		.compatible = "st,lis2hh12",
>  		.data = LIS2HH12_ACCEL_DEV_NAME,
>  	},
> +	{
> +		.compatible = "silan,sc7a20",
> +		.data = SC7A20_ACCEL_DEV_NAME,
> +	},
>  	{},
>  };
>  MODULE_DEVICE_TABLE(of, st_accel_of_match);
> @@ -142,6 +146,7 @@ static const struct i2c_device_id st_accel_id_table[] = {
>  	{ LIS3DE_ACCEL_DEV_NAME },
>  	{ LIS2DE12_ACCEL_DEV_NAME },
>  	{ LIS2HH12_ACCEL_DEV_NAME },
> +	{ SC7A20_ACCEL_DEV_NAME },
>  	{},
>  };
>  MODULE_DEVICE_TABLE(i2c, st_accel_id_table);
Linus Walleij Jan. 31, 2022, 11:23 a.m. UTC | #2
On Sun, Jan 30, 2022 at 3:04 PM Jonathan Cameron <jic23@kernel.org> wrote:

> This is nasty as 0x11 is a valid who am I for an LIS3DHH which is a very
> different device.

The WAI value is just a second line check anyway, the device is probed
from the compatible, this is just checked to make sure the device is
what it says it is. Annoying, but it will do the job.

> It's worth noting that a good part of the maintenance of this driver is
> done by ST employees who are probably less than happy with seeing
> a clone (with bugs) supported.  So support is likely to be somewhat best
> effort / not going to deliberately break support for this part but no
> means to test it. Hopefully we'll remember to cc you to test anything new added to
> the driver.  Clones aren't always perfect!

Linux began with people running it on IBM PC clones... ;)

I would assume good faith, especially with the silicon shortage
plaguing us it is
perfectly possible that this is a fully licensed copy. I think the two
derivatives of the AK8974 magnetometer for example are
legally transferred IP, we just don't know the details behind the curtain.

Yours,
Linus Walleij
diff mbox series

Patch

diff --git a/drivers/iio/accel/st_accel.h b/drivers/iio/accel/st_accel.h
index 8750dea56fcb..00e056c21bfc 100644
--- a/drivers/iio/accel/st_accel.h
+++ b/drivers/iio/accel/st_accel.h
@@ -36,6 +36,7 @@  enum st_accel_type {
 	LIS3DHH,
 	LIS2DE12,
 	LIS2HH12,
+	SC7A20,
 	ST_ACCEL_MAX,
 };
 
@@ -61,6 +62,7 @@  enum st_accel_type {
 #define LIS3DE_ACCEL_DEV_NAME		"lis3de"
 #define LIS2DE12_ACCEL_DEV_NAME		"lis2de12"
 #define LIS2HH12_ACCEL_DEV_NAME		"lis2hh12"
+#define SC7A20_ACCEL_DEV_NAME		"sc7a20"
 
 #ifdef CONFIG_IIO_BUFFER
 int st_accel_allocate_ring(struct iio_dev *indio_dev);
diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
index 31ea19d0ba71..d9aa0ff1922b 100644
--- a/drivers/iio/accel/st_accel_core.c
+++ b/drivers/iio/accel/st_accel_core.c
@@ -1087,6 +1087,85 @@  static const struct st_sensor_settings st_accel_sensors_settings[] = {
 		.multi_read_bit = true,
 		.bootime = 2,
 	},
+	{
+		.wai = 0x11,
+		.wai_addr = ST_SENSORS_DEFAULT_WAI_ADDRESS,
+		.sensors_supported = {
+			[0] = SC7A20_ACCEL_DEV_NAME,
+		},
+		.ch = (struct iio_chan_spec *)st_accel_12bit_channels,
+		.odr = {
+			.addr = 0x20,
+			.mask = 0xf0,
+			.odr_avl = {
+				{ .hz = 1, .value = 0x01, },
+				{ .hz = 10, .value = 0x02, },
+				{ .hz = 25, .value = 0x03, },
+				{ .hz = 50, .value = 0x04, },
+				{ .hz = 100, .value = 0x05, },
+				{ .hz = 200, .value = 0x06, },
+				{ .hz = 400, .value = 0x07, },
+				{ .hz = 1600, .value = 0x08, },
+			},
+		},
+		.pw = {
+			.addr = 0x20,
+			.mask = 0xf0,
+			.value_off = ST_SENSORS_DEFAULT_POWER_OFF_VALUE,
+		},
+		.enable_axis = {
+			.addr = ST_SENSORS_DEFAULT_AXIS_ADDR,
+			.mask = ST_SENSORS_DEFAULT_AXIS_MASK,
+		},
+		.fs = {
+			.addr = 0x23,
+			.mask = 0x30,
+			.fs_avl = {
+				[0] = {
+					.num = ST_ACCEL_FS_AVL_2G,
+					.value = 0x00,
+					.gain = IIO_G_TO_M_S_2(1000),
+				},
+				[1] = {
+					.num = ST_ACCEL_FS_AVL_4G,
+					.value = 0x01,
+					.gain = IIO_G_TO_M_S_2(2000),
+				},
+				[2] = {
+					.num = ST_ACCEL_FS_AVL_8G,
+					.value = 0x02,
+					.gain = IIO_G_TO_M_S_2(4000),
+				},
+				[3] = {
+					.num = ST_ACCEL_FS_AVL_16G,
+					.value = 0x03,
+					.gain = IIO_G_TO_M_S_2(12000),
+				},
+			},
+		},
+		.bdu = {
+			.addr = 0x23,
+			.mask = 0x80,
+		},
+		.drdy_irq = {
+			.int1 = {
+				.addr = 0x22,
+				.mask = 0x10,
+			},
+			.addr_ihl = 0x25,
+			.mask_ihl = 0x02,
+			.stat_drdy = {
+				.addr = ST_SENSORS_DEFAULT_STAT_ADDR,
+				.mask = 0x07,
+			},
+		},
+		.sim = {
+			.addr = 0x23,
+			.value = BIT(0),
+		},
+		.multi_read_bit = true,
+		.bootime = 2,
+	},
 };
 
 /* Default accel DRDY is available on INT1 pin */
diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
index c0ce78eebad9..7f5888570e87 100644
--- a/drivers/iio/accel/st_accel_i2c.c
+++ b/drivers/iio/accel/st_accel_i2c.c
@@ -107,6 +107,10 @@  static const struct of_device_id st_accel_of_match[] = {
 		.compatible = "st,lis2hh12",
 		.data = LIS2HH12_ACCEL_DEV_NAME,
 	},
+	{
+		.compatible = "silan,sc7a20",
+		.data = SC7A20_ACCEL_DEV_NAME,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, st_accel_of_match);
@@ -142,6 +146,7 @@  static const struct i2c_device_id st_accel_id_table[] = {
 	{ LIS3DE_ACCEL_DEV_NAME },
 	{ LIS2DE12_ACCEL_DEV_NAME },
 	{ LIS2HH12_ACCEL_DEV_NAME },
+	{ SC7A20_ACCEL_DEV_NAME },
 	{},
 };
 MODULE_DEVICE_TABLE(i2c, st_accel_id_table);