* [PATCH v2 1/2] i2c: add i2c_get_device_id() to get the standard i2c device id
2018-03-05 20:58 [PATCH v2 0/2] check I2C device id for pca984x chips Peter Rosin
@ 2018-03-05 20:58 ` Peter Rosin
2018-03-05 20:58 ` [PATCH v2 2/2] i2c: mux: pca954x: verify the device id of the pca984x chips Peter Rosin
2018-03-10 0:05 ` [PATCH v2 0/2] check I2C device id for " Peter Rosin
2 siblings, 0 replies; 4+ messages in thread
From: Peter Rosin @ 2018-03-05 20:58 UTC (permalink / raw)
To: linux-kernel; +Cc: Peter Rosin, Wolfram Sang, Adrian Fiergolski, linux-i2c
Can be used during probe to double check that the probed device is
what is expected.
Loosely based on code from Adrian Fiergolski <adrian.fiergolski@cern.ch>.
Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/i2c-core-base.c | 33 +++++++++++++++++++++++++++++++++
include/linux/i2c.h | 30 ++++++++++++++++++++++++++++++
2 files changed, 63 insertions(+)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 5a00bf443d06..aa03eeb43814 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -58,6 +58,8 @@
#define I2C_ADDR_7BITS_MAX 0x77
#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1)
+#define I2C_ADDR_DEVICE_ID 0x7c
+
/*
* core_lock protects i2c_adapter_idr, and guarantees that device detection,
* deletion of detected devices, and attach_adapter calls are serialized
@@ -1968,6 +1970,37 @@ int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf,
}
EXPORT_SYMBOL(i2c_transfer_buffer_flags);
+/**
+ * i2c_get_device_id - get manufacturer, part id and die revision of a device
+ * @client: The device to query
+ * @id: The queried information
+ *
+ * Returns negative errno on error, zero on success.
+ */
+int i2c_get_device_id(const struct i2c_client *client,
+ struct i2c_device_identity *id)
+{
+ struct i2c_adapter *adap = client->adapter;
+ union i2c_smbus_data raw_id;
+ int ret;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+ return -EOPNOTSUPP;
+
+ raw_id.block[0] = 3;
+ ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0,
+ I2C_SMBUS_READ, client->addr << 1,
+ I2C_SMBUS_I2C_BLOCK_DATA, &raw_id);
+ if (ret)
+ return ret;
+
+ id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4);
+ id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3);
+ id->die_revision = raw_id.block[3] & 0x7;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(i2c_get_device_id);
+
/* ----------------------------------------------------
* the i2c address scanning function
* Will not work for 10-bit addresses!
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 419a38e7c315..44ad14e016b5 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -47,6 +47,7 @@ struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
+struct i2c_device_identity;
union i2c_smbus_data;
struct i2c_board_info;
enum i2c_slave_event;
@@ -186,8 +187,37 @@ extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
extern s32
i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
u8 command, u8 length, u8 *values);
+int i2c_get_device_id(const struct i2c_client *client,
+ struct i2c_device_identity *id);
#endif /* I2C */
+/**
+ * struct i2c_device_identity - i2c client device identification
+ * @manufacturer_id: 0 - 4095, database maintained by NXP
+ * @part_id: 0 - 511, according to manufacturer
+ * @die_revision: 0 - 7, according to manufacturer
+ */
+struct i2c_device_identity {
+ u16 manufacturer_id;
+#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
+#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
+#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
+#define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
+#define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
+#define I2C_DEVICE_ID_ANALOG_DEVICES 5
+#define I2C_DEVICE_ID_STMICROELECTRONICS 6
+#define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
+#define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
+#define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
+#define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
+#define I2C_DEVICE_ID_FLIR 11
+#define I2C_DEVICE_ID_O2MICRO 12
+#define I2C_DEVICE_ID_ATMEL 13
+#define I2C_DEVICE_ID_NONE 0xffff
+ u16 part_id;
+ u8 die_revision;
+};
+
enum i2c_alert_protocol {
I2C_PROTOCOL_SMBUS_ALERT,
I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
--
2.11.0
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v2 2/2] i2c: mux: pca954x: verify the device id of the pca984x chips
2018-03-05 20:58 [PATCH v2 0/2] check I2C device id for pca984x chips Peter Rosin
2018-03-05 20:58 ` [PATCH v2 1/2] i2c: add i2c_get_device_id() to get the standard i2c device id Peter Rosin
@ 2018-03-05 20:58 ` Peter Rosin
2018-03-10 0:05 ` [PATCH v2 0/2] check I2C device id for " Peter Rosin
2 siblings, 0 replies; 4+ messages in thread
From: Peter Rosin @ 2018-03-05 20:58 UTC (permalink / raw)
To: linux-kernel; +Cc: Peter Rosin, Wolfram Sang, Adrian Fiergolski, linux-i2c
Make sure to not disallow the chips on adapters that are not capable
of reading the device id, but also make sure to check the device id
before writing to the chip.
Tested-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/muxes/i2c-mux-pca954x.c | 55 +++++++++++++++++++++++++++++++++----
1 file changed, 49 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index fbb84c7ef282..09bafd3e68fa 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -77,6 +77,7 @@ struct chip_desc {
pca954x_ismux = 0,
pca954x_isswi
} muxtype;
+ struct i2c_device_identity id;
};
struct pca954x {
@@ -97,59 +98,83 @@ static const struct chip_desc chips[] = {
.nchans = 2,
.enable = 0x4,
.muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9542] = {
.nchans = 2,
.enable = 0x4,
.has_irq = 1,
.muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9543] = {
.nchans = 2,
.has_irq = 1,
.muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9544] = {
.nchans = 4,
.enable = 0x4,
.has_irq = 1,
.muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9545] = {
.nchans = 4,
.has_irq = 1,
.muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9546] = {
.nchans = 4,
.muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9547] = {
.nchans = 8,
.enable = 0x8,
.muxtype = pca954x_ismux,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9548] = {
.nchans = 8,
.muxtype = pca954x_isswi,
+ .id = { .manufacturer_id = I2C_DEVICE_ID_NONE },
},
[pca_9846] = {
.nchans = 4,
.muxtype = pca954x_isswi,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x10b,
+ },
},
[pca_9847] = {
.nchans = 8,
.enable = 0x8,
.muxtype = pca954x_ismux,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x108,
+ },
},
[pca_9848] = {
.nchans = 8,
.muxtype = pca954x_isswi,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x10a,
+ },
},
[pca_9849] = {
.nchans = 4,
.enable = 0x4,
.muxtype = pca954x_ismux,
+ .id = {
+ .manufacturer_id = I2C_DEVICE_ID_NXP_SEMICONDUCTORS,
+ .part_id = 0x109,
+ },
},
};
@@ -369,6 +394,30 @@ static int pca954x_probe(struct i2c_client *client,
if (IS_ERR(gpio))
return PTR_ERR(gpio);
+ match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
+ if (match)
+ data->chip = of_device_get_match_data(&client->dev);
+ else
+ data->chip = &chips[id->driver_data];
+
+ if (data->chip->id.manufacturer_id != I2C_DEVICE_ID_NONE) {
+ struct i2c_device_identity id;
+
+ ret = i2c_get_device_id(client, &id);
+ if (ret && ret != -EOPNOTSUPP)
+ return ret;
+
+ if (!ret &&
+ (id.manufacturer_id != data->chip->id.manufacturer_id ||
+ id.part_id != data->chip->id.part_id)) {
+ dev_warn(&client->dev,
+ "unexpected device id %03x-%03x-%x\n",
+ id.manufacturer_id, id.part_id,
+ id.die_revision);
+ return -ENODEV;
+ }
+ }
+
/* Write the mux register at addr to verify
* that the mux is in fact present. This also
* initializes the mux to disconnected state.
@@ -378,12 +427,6 @@ static int pca954x_probe(struct i2c_client *client,
return -ENODEV;
}
- match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
- if (match)
- data->chip = of_device_get_match_data(&client->dev);
- else
- data->chip = &chips[id->driver_data];
-
data->last_chan = 0; /* force the first selection */
idle_disconnect_dt = of_node &&
--
2.11.0
^ permalink raw reply [flat|nested] 4+ messages in thread