[PATCH] ics932s401: New driver

[PATCH] ics932s401: New driver

[Darrick J. Wong]

The ics932s401 is a clock generator chip.  This driver allows users to read
the current clock outputs.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---

 Documentation/ics932s401  |   31 +++
 drivers/misc/Kconfig      |   10 +
 drivers/misc/Makefile     |    1 
 drivers/misc/ics932s401.c |  515 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 557 insertions(+), 0 deletions(-)

diff --git a/Documentation/ics932s401 b/Documentation/ics932s401
new file mode 100644
index 0000000..07a739f
--- /dev/null
+++ b/Documentation/ics932s401
@@ -0,0 +1,31 @@
+Kernel driver ics932s401
+======================
+
+Supported chips:
+  * IDT ICS932S401
+    Prefix: 'ics932s401'
+    Addresses scanned: I2C 0x69
+    Datasheet: Publically available at the IDT website
+
+Author: Darrick J. Wong
+
+Description
+-----------
+
+This driver implements support for the IDT ICS932S401 chip family.
+
+This chip has 4 clock outputs--a base clock for the CPU (which is likely
+multiplied to get the real CPU clock), a system clock, a PCI clock, a USB
+clock, and a reference clock.  The driver reports selected and actual
+frequency.  If spread spectrum mode is enabled, the driver also reports by what
+percent the clock signal is being spread, which should be between 0 and -0.5%.
+All frequencies are reported in KHz.
+
+The ICS932S401 monitors all inputs continuously. The driver will not read
+the registers more often than once every other second.
+
+Special Features
+----------------
+
+The clocks could be reprogrammed to increase system speed.  I will not help you
+do this, as you risk damaging your system!
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 9494400..6917d61 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -227,6 +227,16 @@ config HP_WMI
          To compile this driver as a module, choose M here: the module will
          be called hp-wmi.
 
+config ICS932S401
+	tristate "Integrated Circuits ICS932S401"
+	depends on I2C && EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Integrated Circuits
+	  ICS932S401 clock control chips.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called ics932s401.
+
 config MSI_LAPTOP
         tristate "MSI Laptop Extras"
         depends on X86
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 909e246..bb14633 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_ATMEL_PWM)		+= atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)		+= atmel-ssc.o
 obj-$(CONFIG_ATMEL_TCLIB)	+= atmel_tclib.o
 obj-$(CONFIG_HP_WMI)		+= hp-wmi.o
+obj-$(CONFIG_ICS932S401)	+= ics932s401.o
 obj-$(CONFIG_TC1100_WMI)	+= tc1100-wmi.o
 obj-$(CONFIG_LKDTM)		+= lkdtm.o
 obj-$(CONFIG_TIFM_CORE)       	+= tifm_core.o
diff --git a/drivers/misc/ics932s401.c b/drivers/misc/ics932s401.c
new file mode 100644
index 0000000..6e43ab4
--- /dev/null
+++ b/drivers/misc/ics932s401.c
@@ -0,0 +1,515 @@
+/*
+ * A driver for the Integrated Circuits ICS932S401
+ * Copyright (C) 2008 IBM
+ *
+ * Author: Darrick J. Wong <djwong@us.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/log2.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
+
+/* Insmod parameters */
+I2C_CLIENT_INSMOD_1(ics932s401);
+
+/* ICS932S401 registers */
+#define ICS932S401_REG_CFG2			0x01
+#define 	ICS932S401_CFG1_SPREAD		0x01
+#define ICS932S401_REG_CFG7			0x06
+#define		ICS932S401_FS_MASK		0x07
+#define	ICS932S401_REG_VENDOR_REV		0x07
+#define		ICS932S401_VENDOR		1
+#define		ICS932S401_VENDOR_MASK		0x0F
+#define		ICS932S401_REV			4
+#define		ICS932S401_REV_SHIFT		4
+#define ICS932S401_REG_DEVICE			0x09
+#define		ICS932S401_DEVICE		11
+#define	ICS932S401_REG_CTRL			0x0A
+#define		ICS932S401_MN_ENABLED		0x80
+#define		ICS932S401_CPU_ALT		0x04
+#define		ICS932S401_SRC_ALT		0x08
+#define ICS932S401_REG_CPU_M_CTRL		0x0B
+#define		ICS932S401_M_MASK		0x3F
+#define	ICS932S401_REG_CPU_N_CTRL		0x0C
+#define	ICS932S401_REG_CPU_SPREAD1		0x0D
+#define ICS932S401_REG_CPU_SPREAD2		0x0E
+#define		ICS932S401_SPREAD_MASK		0x7FFF
+#define ICS932S401_REG_SRC_M_CTRL		0x0F
+#define ICS932S401_REG_SRC_N_CTRL		0x10
+#define	ICS932S401_REG_SRC_SPREAD1		0x11
+#define ICS932S401_REG_SRC_SPREAD2		0x12
+#define ICS932S401_REG_CPU_DIVISOR		0x13
+#define 	ICS932S401_CPU_DIVISOR_SHIFT	4
+#define ICS932S401_REG_PCISRC_DIVISOR		0x14
+#define		ICS932S401_SRC_DIVISOR_MASK	0x0F
+#define		ICS932S401_PCI_DIVISOR_SHIFT	4
+
+/* Base clock is 14.318MHz */
+#define BASE_CLOCK				14318
+
+#define NUM_REGS				21
+#define NUM_MIRRORED_REGS			15
+
+static int regs_to_copy[NUM_MIRRORED_REGS] = {
+	ICS932S401_REG_CFG2,
+	ICS932S401_REG_CFG7,
+	ICS932S401_REG_VENDOR_REV,
+	ICS932S401_REG_DEVICE,
+	ICS932S401_REG_CTRL,
+	ICS932S401_REG_CPU_M_CTRL,
+	ICS932S401_REG_CPU_N_CTRL,
+	ICS932S401_REG_CPU_SPREAD1,
+	ICS932S401_REG_CPU_SPREAD2,
+	ICS932S401_REG_SRC_M_CTRL,
+	ICS932S401_REG_SRC_N_CTRL,
+	ICS932S401_REG_SRC_SPREAD1,
+	ICS932S401_REG_SRC_SPREAD2,
+	ICS932S401_REG_CPU_DIVISOR,
+	ICS932S401_REG_PCISRC_DIVISOR,
+};
+
+/* How often do we reread sensors values? (In jiffies) */
+#define SENSOR_REFRESH_INTERVAL	(2 * HZ)
+
+/* How often do we reread sensor limit values? (In jiffies) */
+#define LIMIT_REFRESH_INTERVAL	(60 * HZ)
+
+struct ics932s401_data {
+	struct attribute_group	attrs;
+	struct mutex		lock;
+	char			sensors_valid;
+	unsigned long		sensors_last_updated;	/* In jiffies */
+
+	u8			regs[NUM_REGS];
+};
+
+static int ics932s401_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id);
+static int ics932s401_detect(struct i2c_client *client, int kind,
+			  struct i2c_board_info *info);
+static int ics932s401_remove(struct i2c_client *client);
+
+static const struct i2c_device_id ics932s401_id[] = {
+	{ "ics932s401", ics932s401 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ics932s401_id);
+
+static struct i2c_driver ics932s401_driver = {
+	.class		= I2C_CLASS_HWMON,
+	.driver = {
+		.name	= "ics932s401",
+	},
+	.probe		= ics932s401_probe,
+	.remove		= ics932s401_remove,
+	.id_table	= ics932s401_id,
+	.detect		= ics932s401_detect,
+	.address_data	= &addr_data,
+};
+
+static struct ics932s401_data *ics932s401_update_device(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct ics932s401_data *data = i2c_get_clientdata(client);
+	unsigned long local_jiffies = jiffies;
+	int i, temp;
+
+	mutex_lock(&data->lock);
+	if (time_before(local_jiffies, data->sensors_last_updated +
+		SENSOR_REFRESH_INTERVAL)
+		&& data->sensors_valid)
+		goto out;
+
+	/*
+	 * Each register must be read as a word and then right shifted 8 bits.
+	 * Not really sure why this is; setting the "byte count programming"
+	 * register to 1 does not fix this problem.
+	 */
+	for (i = 0; i < NUM_MIRRORED_REGS; i++) {
+		temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
+		data->regs[regs_to_copy[i]] = temp >> 8;
+	}
+
+	data->sensors_last_updated = local_jiffies;
+	data->sensors_valid = 1;
+
+out:
+	mutex_unlock(&data->lock);
+	return data;
+}
+
+static ssize_t show_spread_enabled(struct device *dev,
+				   struct device_attribute *devattr,
+				   char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+
+	if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
+		return sprintf(buf, "1\n");
+
+	return sprintf(buf, "0\n");
+}
+
+/* bit to cpu khz map */
+static const int fs_speeds[] = {
+	266666,
+	133333,
+	200000,
+	166666,
+	333333,
+	100000,
+	400000,
+	0,
+};
+
+/* clock divisor map */
+static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
+			       24, 40, 120};
+
+/* Calculate CPU frequency from the M/N registers. */
+static int calculate_cpu_freq(struct ics932s401_data *data)
+{
+	int m, n, freq;
+
+	m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
+	n = data->regs[ICS932S401_REG_CPU_N_CTRL];
+
+	/* Pull in bits 8 & 9 from the M register */
+	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
+	n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
+
+	freq = BASE_CLOCK * (n + 8) / (m + 2);
+	freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
+			 ICS932S401_CPU_DIVISOR_SHIFT];
+
+	return freq;
+}
+
+static ssize_t show_cpu_clock(struct device *dev,
+			      struct device_attribute *devattr,
+			      char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+
+	return sprintf(buf, "%d\n", calculate_cpu_freq(data));
+}
+
+static ssize_t show_cpu_clock_sel(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+	int freq;
+
+	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
+		freq = calculate_cpu_freq(data);
+	else {
+		/* Freq is neatly wrapped up for us */
+		int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
+		freq = fs_speeds[fid];
+		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
+			switch (freq) {
+			case 166666:
+				freq = 160000;
+				break;
+			case 333333:
+				freq = 320000;
+				break;
+			}
+		}
+	}
+
+	return sprintf(buf, "%d\n", freq);
+}
+
+/* Calculate SRC frequency from the M/N registers. */
+static int calculate_src_freq(struct ics932s401_data *data)
+{
+	int m, n, freq;
+
+	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
+	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
+
+	/* Pull in bits 8 & 9 from the M register */
+	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
+	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
+
+	freq = BASE_CLOCK * (n + 8) / (m + 2);
+	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
+			 ICS932S401_SRC_DIVISOR_MASK];
+
+	return freq;
+}
+
+static ssize_t show_src_clock(struct device *dev,
+			      struct device_attribute *devattr,
+			      char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+
+	return sprintf(buf, "%d\n", calculate_src_freq(data));
+}
+
+static ssize_t show_src_clock_sel(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+	int freq;
+
+	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
+		freq = calculate_src_freq(data);
+	else
+		/* Freq is neatly wrapped up for us */
+		if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
+		    data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
+			freq = 96000;
+		else
+			freq = 100000;
+
+	return sprintf(buf, "%d\n", freq);
+}
+
+/* Calculate PCI frequency from the SRC M/N registers. */
+static int calculate_pci_freq(struct ics932s401_data *data)
+{
+	int m, n, freq;
+
+	m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
+	n = data->regs[ICS932S401_REG_SRC_N_CTRL];
+
+	/* Pull in bits 8 & 9 from the M register */
+	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
+	n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
+
+	freq = BASE_CLOCK * (n + 8) / (m + 2);
+	freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
+			 ICS932S401_PCI_DIVISOR_SHIFT];
+
+	return freq;
+}
+
+static ssize_t show_pci_clock(struct device *dev,
+			      struct device_attribute *devattr,
+			      char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+
+	return sprintf(buf, "%d\n", calculate_pci_freq(data));
+}
+
+static ssize_t show_pci_clock_sel(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+	int freq;
+
+	if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
+		freq = calculate_pci_freq(data);
+	else
+		freq = 33333;
+
+	return sprintf(buf, "%d\n", freq);
+}
+
+static ssize_t show_value(struct device *dev,
+			  struct device_attribute *devattr,
+			  char *buf);
+
+static ssize_t show_spread(struct device *dev,
+			   struct device_attribute *devattr,
+			   char *buf);
+
+static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
+static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
+static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
+static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
+static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
+static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
+static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
+static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
+static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
+static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
+static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
+
+static struct attribute *ics932s401_attr[] =
+{
+	&dev_attr_spread_enabled.attr,
+	&dev_attr_cpu_clock_selection.attr,
+	&dev_attr_cpu_clock.attr,
+	&dev_attr_src_clock_selection.attr,
+	&dev_attr_src_clock.attr,
+	&dev_attr_pci_clock_selection.attr,
+	&dev_attr_pci_clock.attr,
+	&dev_attr_usb_clock.attr,
+	&dev_attr_ref_clock.attr,
+	&dev_attr_cpu_spread.attr,
+	&dev_attr_src_spread.attr,
+	NULL
+};
+
+static ssize_t show_value(struct device *dev,
+			  struct device_attribute *devattr,
+			  char *buf)
+{
+	int x;
+
+	if (devattr == &dev_attr_usb_clock)
+		x = 48000;
+	else if (devattr == &dev_attr_ref_clock)
+		x = BASE_CLOCK;
+	else
+		BUG();
+
+	return sprintf(buf, "%d\n", x);
+}
+
+static ssize_t show_spread(struct device *dev,
+			   struct device_attribute *devattr,
+			   char *buf)
+{
+	struct ics932s401_data *data = ics932s401_update_device(dev);
+	int reg;
+	unsigned long val;
+
+	if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
+		return sprintf(buf, "0%%\n");
+
+	if (devattr == &dev_attr_src_spread)
+		reg = ICS932S401_REG_SRC_SPREAD1;
+	else if (devattr == &dev_attr_cpu_spread)
+		reg = ICS932S401_REG_CPU_SPREAD1;
+	else
+		BUG();
+
+	val = data->regs[reg] | (data->regs[reg + 1] << 8);
+	val &= ICS932S401_SPREAD_MASK;
+
+	/* Scale 0..2^14 to -0.5. */
+	val = 500000 * val / 16384;
+	return sprintf(buf, "-0.%lu%%\n", val);
+}
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int ics932s401_detect(struct i2c_client *client, int kind,
+			  struct i2c_board_info *info)
+{
+	struct i2c_adapter *adapter = client->adapter;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+		return -ENODEV;
+
+	if (kind <= 0) {
+		int vendor, device, revision;
+
+		vendor = i2c_smbus_read_word_data(client,
+						  ICS932S401_REG_VENDOR_REV);
+		vendor >>= 8;
+		revision = vendor >> ICS932S401_REV_SHIFT;
+		vendor &= ICS932S401_VENDOR_MASK;
+		if (vendor != ICS932S401_VENDOR)
+			return -ENODEV;
+
+		device = i2c_smbus_read_word_data(client,
+						  ICS932S401_REG_DEVICE);
+		device >>= 8;
+		if (device != ICS932S401_DEVICE)
+			return -ENODEV;
+
+		if (revision != ICS932S401_REV)
+			dev_info(&adapter->dev, "Unknown revision %d\n",
+				 revision);
+	} else
+		dev_dbg(&adapter->dev, "detection forced\n");
+
+	strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
+
+	return 0;
+}
+
+static int ics932s401_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct ics932s401_data *data;
+	int err;
+
+	data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	i2c_set_clientdata(client, data);
+	mutex_init(&data->lock);
+
+	dev_info(&client->dev, "%s chip found\n", client->name);
+
+	/* Register sysfs hooks */
+	data->attrs.attrs = ics932s401_attr;
+	err = sysfs_create_group(&client->dev.kobj, &data->attrs);
+	if (err)
+		goto exit_free;
+
+	return 0;
+
+exit_free:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int ics932s401_remove(struct i2c_client *client)
+{
+	struct ics932s401_data *data = i2c_get_clientdata(client);
+
+	sysfs_remove_group(&client->dev.kobj, &data->attrs);
+	kfree(data);
+	return 0;
+}
+
+static int __init ics932s401_init(void)
+{
+	return i2c_add_driver(&ics932s401_driver);
+}
+
+static void __exit ics932s401_exit(void)
+{
+	i2c_del_driver(&ics932s401_driver);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
+MODULE_DESCRIPTION("ICS932S401 driver");
+MODULE_LICENSE("GPL");
+
+module_init(ics932s401_init);
+module_exit(ics932s401_exit);
+
+/* IBM IntelliStation Z30 */
+MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
+MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
+
+/* IBM x3650/x3550 */
+MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
+MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");

Re: [PATCH] ics932s401: New driver

[Andrew Morton]

These are nice-looking drivers and I'm inclined to slip them into
2.6.28, but..

On Fri, 07 Nov 2008 11:11:10 -0800
"Darrick J. Wong" <djwong@us.ibm.com> wrote:

> +/* Addresses to scan */
> +static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };

These are the sorts of drivers which must go blindly poking at
hardwired IO addresses, aren't they?  So if someone accidentally
compiles it up and loads it, it will reach out and fry their pr0n
collection?

Re: [PATCH] ics932s401: New driver

[Darrick J. Wong]

On Fri, Nov 07, 2008 at 11:31:42AM -0800, Andrew Morton wrote:
> 
> These are nice-looking drivers and I'm inclined to slip them into
> 2.6.28, but..
> 
> On Fri, 07 Nov 2008 11:11:10 -0800
> "Darrick J. Wong" <djwong@us.ibm.com> wrote:
> 
> > +/* Addresses to scan */
> > +static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
> 
> These are the sorts of drivers which must go blindly poking at
> hardwired IO addresses, aren't they?  So if someone accidentally
> compiles it up and loads it, it will reach out and fry their pr0n
> collection?

Yep.  Alas, there's not a whole lot we can do about that, other than say
"insmodder beware".  Were it a hwmon driver, we could blacklist it in
sensors-detct, but Jean already NAK'd it for hwmon.  I plan to stick to
the DMI whitelist and add a DMI blacklist if necessary.

Of course, if you're really intent upon frying (someone else's) pr0n
collection... this chip can help with that.

--D