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From: Peter Rosin <peda@axentia.se>
To: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Cc: Peter Rosin <peda@axentia.se>, Wolfram Sang <wsa@the-dreams.de>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 2/2] i2c: mux: pca954x: verify the device id of the pca984x chips
Date: Mon, 22 Jan 2018 12:36:57 +0100	[thread overview]
Message-ID: <20180122113657.32094-3-peda@axentia.se> (raw)
In-Reply-To: <20180122113657.32094-1-peda@axentia.se>

Make sure to not disallow the chips on adapters that are not capable
of reading the device id.

Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/i2c/muxes/i2c-mux-pca954x.c | 43 +++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index fbb84c7ef282..ff0c7a144fbb 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,
+		},
 	},
 };
 
@@ -384,6 +409,24 @@ static int pca954x_probe(struct i2c_client *client,
 	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;
+		}
+	}
+
 	data->last_chan = 0;		   /* force the first selection */
 
 	idle_disconnect_dt = of_node &&
-- 
2.11.0

  parent reply	other threads:[~2018-01-22 11:37 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-22 11:36 [RFC PATCH 0/2] check I2C device id for pca984x chips Peter Rosin
2018-01-22 11:36 ` [RFC PATCH 1/2] i2c: add i2c_get_device_id() to get the standard i2c device id Peter Rosin
2018-03-04 21:47   ` Peter Rosin
2018-03-05 15:51   ` Wolfram Sang
2018-03-05 16:06     ` Peter Rosin
2018-03-05 16:27       ` Wolfram Sang
2018-01-22 11:36 ` Peter Rosin [this message]
2018-03-05 15:53   ` [RFC PATCH 2/2] i2c: mux: pca954x: verify the device id of the pca984x chips Wolfram Sang
2018-03-05 15:55     ` Peter Rosin
2018-03-05 16:29       ` Wolfram Sang
2018-01-26 16:33 ` [RFC PATCH 0/2] check I2C device id for " Adrian Fiergolski
2018-01-26 16:33   ` Adrian Fiergolski
2018-01-27  8:37   ` Peter Rosin
2018-01-29 17:38     ` Adrian Fiergolski
2018-01-29 17:38       ` Adrian Fiergolski
2018-02-01 14:41       ` Peter Rosin

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