ics932s401: new clock generator chip driver

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 557 insertions, 0 deletions

diff --git a/Documentation/ics932s401 b/Documentation/ics932s401
new file mode 100644
index 000000000000..07a739f406d8
--- /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 4494ad27cbf1..dcac7ca76937 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 909e2468cdc9..bb14633d1362 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 000000000000..6e43ab4231ae
--- /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,