hwmon: (i5k_amb) New memory temperature sensor driver

New driver to read FB-DIMM temperature sensors on systems with the
Intel 5000 series chipsets.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>

3 files changed, 542 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 700a1657554..a0445bea9f7 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -216,6 +216,16 @@ config SENSORS_DS1621
           This driver can also be built as a module.  If so, the module
           will be called ds1621.
 
+config SENSORS_I5K_AMB
+        tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
+        depends on PCI && EXPERIMENTAL
+        help
+          If you say yes here you get support for FB-DIMM AMB temperature
+          monitoring chips on systems with the Intel 5000 series chipset.
+
+          This driver can also be built as a module. If so, the module
+          will be called i5k_amb.
+
 config SENSORS_F71805F
         tristate "Fintek F71805F/FG, F71806F/FG and F71872F/FG"
         depends on EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 6da3eef9430..55595f6e1aa 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_SENSORS_FSCPOS)	+= fscpos.o
 obj-$(CONFIG_SENSORS_GL518SM)   += gl518sm.o
 obj-$(CONFIG_SENSORS_GL520SM)   += gl520sm.o
 obj-$(CONFIG_SENSORS_HDAPS)     += hdaps.o
+obj-$(CONFIG_SENSORS_I5K_AMB)   += i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMPEX)    += ibmpex.o
 obj-$(CONFIG_SENSORS_IT87)      += it87.o
 obj-$(CONFIG_SENSORS_K8TEMP)    += k8temp.o
diff --git a/drivers/hwmon/i5k_amb.c b/drivers/hwmon/i5k_amb.c
new file mode 100644
index 00000000000..7fdbe810e8e
--- /dev/null
+++ b/drivers/hwmon/i5k_amb.c
@@ -0,0 +1,531 @@
+/*
+ * A hwmon driver for the Intel 5000 series chipset FB-DIMM AMB
+ * temperature sensors
+ * Copyright (C) 2007 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/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/log2.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+
+#define DRVNAME "i5k_amb"
+
+#define I5K_REG_AMB_BASE_ADDR           0x48
+#define I5K_REG_AMB_LEN_ADDR            0x50
+#define I5K_REG_CHAN0_PRESENCE_ADDR     0x64
+#define I5K_REG_CHAN1_PRESENCE_ADDR     0x66
+
+#define AMB_REG_TEMP_MIN_ADDR           0x80
+#define AMB_REG_TEMP_MID_ADDR           0x81
+#define AMB_REG_TEMP_MAX_ADDR           0x82
+#define AMB_REG_TEMP_STATUS_ADDR        0x84
+#define AMB_REG_TEMP_ADDR               0x85
+
+#define AMB_CONFIG_SIZE                 2048
+#define AMB_FUNC_3_OFFSET               768
+
+#define AMB_REG_TEMP_STATUS(amb)        ((amb) * AMB_CONFIG_SIZE + \
+                        AMB_FUNC_3_OFFSET + AMB_REG_TEMP_STATUS_ADDR)
+#define AMB_REG_TEMP_MIN(amb)           ((amb) * AMB_CONFIG_SIZE + \
+                        AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MIN_ADDR)
+#define AMB_REG_TEMP_MID(amb)           ((amb) * AMB_CONFIG_SIZE + \
+                        AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MID_ADDR)
+#define AMB_REG_TEMP_MAX(amb)           ((amb) * AMB_CONFIG_SIZE + \
+                        AMB_FUNC_3_OFFSET + AMB_REG_TEMP_MAX_ADDR)
+#define AMB_REG_TEMP(amb)               ((amb) * AMB_CONFIG_SIZE + \
+                        AMB_FUNC_3_OFFSET + AMB_REG_TEMP_ADDR)
+
+#define MAX_MEM_CHANNELS                4
+#define MAX_AMBS_PER_CHANNEL            16
+#define MAX_AMBS                        (MAX_MEM_CHANNELS * \
+                                         MAX_AMBS_PER_CHANNEL)
+/*
+ * Ugly hack: For some reason the highest bit is set if there
+ * are _any_ DIMMs in the channel.  Attempting to read from
+ * this "high-order" AMB results in a memory bus error, so
+ * for now we'll just ignore that top bit, even though that
+ * might prevent us from seeing the 16th DIMM in the channel.
+ */
+#define REAL_MAX_AMBS_PER_CHANNEL       15
+#define KNOBS_PER_AMB                   5
+
+#define AMB_NUM_FROM_REG(byte_num, bit_num)     ((byte_num) * \
+                        MAX_AMBS_PER_CHANNEL) + (bit_num)
+
+#define AMB_SYSFS_NAME_LEN              16
+struct i5k_device_attribute {
+        struct sensor_device_attribute s_attr;
+        char name[AMB_SYSFS_NAME_LEN];
+};
+
+struct i5k_amb_data {
+        struct device *hwmon_dev;
+
+        unsigned long amb_base;
+        unsigned long amb_len;
+        u16 amb_present[MAX_MEM_CHANNELS];
+        void __iomem *amb_mmio;
+        struct i5k_device_attribute *attrs;
+        unsigned int num_attrs;
+};
+
+static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
+                         char *buf)
+{
+        return sprintf(buf, "%s\n", DRVNAME);
+}
+
+
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+static struct platform_device *amb_pdev;
+
+static u8 amb_read_byte(struct i5k_amb_data *data, unsigned long offset)
+{
+        return ioread8(data->amb_mmio + offset);
+}
+
+static void amb_write_byte(struct i5k_amb_data *data, unsigned long offset,
+                           u8 val)
+{
+        iowrite8(val, data->amb_mmio + offset);
+}
+
+static ssize_t show_amb_alarm(struct device *dev,
+                             struct device_attribute *devattr,
+                             char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+
+        if (!(amb_read_byte(data, AMB_REG_TEMP_STATUS(attr->index)) & 0x20) &&
+             (amb_read_byte(data, AMB_REG_TEMP_STATUS(attr->index)) & 0x8))
+                return sprintf(buf, "1\n");
+        else
+                return sprintf(buf, "0\n");
+}
+
+static ssize_t store_amb_min(struct device *dev,
+                             struct device_attribute *devattr,
+                             const char *buf,
+                             size_t count)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
+
+        if (temp > 255)
+                temp = 255;
+
+        amb_write_byte(data, AMB_REG_TEMP_MIN(attr->index), temp);
+        return count;
+}
+
+static ssize_t store_amb_mid(struct device *dev,
+                             struct device_attribute *devattr,
+                             const char *buf,
+                             size_t count)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
+
+        if (temp > 255)
+                temp = 255;
+
+        amb_write_byte(data, AMB_REG_TEMP_MID(attr->index), temp);
+        return count;
+}
+
+static ssize_t store_amb_max(struct device *dev,
+                             struct device_attribute *devattr,
+                             const char *buf,
+                             size_t count)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        unsigned long temp = simple_strtoul(buf, NULL, 10) / 500;
+
+        if (temp > 255)
+                temp = 255;
+
+        amb_write_byte(data, AMB_REG_TEMP_MAX(attr->index), temp);
+        return count;
+}
+
+static ssize_t show_amb_min(struct device *dev,
+                             struct device_attribute *devattr,
+                             char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        return sprintf(buf, "%d\n",
+                500 * amb_read_byte(data, AMB_REG_TEMP_MIN(attr->index)));
+}
+
+static ssize_t show_amb_mid(struct device *dev,
+                             struct device_attribute *devattr,
+                             char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        return sprintf(buf, "%d\n",
+                500 * amb_read_byte(data, AMB_REG_TEMP_MID(attr->index)));
+}
+
+static ssize_t show_amb_max(struct device *dev,
+                             struct device_attribute *devattr,
+                             char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        return sprintf(buf, "%d\n",
+                500 * amb_read_byte(data, AMB_REG_TEMP_MAX(attr->index)));
+}
+
+static ssize_t show_amb_temp(struct device *dev,
+                             struct device_attribute *devattr,
+                             char *buf)
+{
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        struct i5k_amb_data *data = dev_get_drvdata(dev);
+        return sprintf(buf, "%d\n",
+                500 * amb_read_byte(data, AMB_REG_TEMP(attr->index)));
+}
+
+static int __devinit i5k_amb_hwmon_init(struct platform_device *pdev)
+{
+        int i, j, k, d = 0;
+        u16 c;
+        int res = 0;
+        int num_ambs = 0;
+        struct i5k_amb_data *data = platform_get_drvdata(pdev);
+
+        /* Count the number of AMBs found */
+        /* ignore the high-order bit, see "Ugly hack" comment above */
+        for (i = 0; i < MAX_MEM_CHANNELS; i++)
+                num_ambs += hweight16(data->amb_present[i] & 0x7fff);
+
+        /* Set up sysfs stuff */
+        data->attrs = kzalloc(sizeof(*data->attrs) * num_ambs * KNOBS_PER_AMB,
+                                GFP_KERNEL);
+        if (!data->attrs)
+                return -ENOMEM;
+        data->num_attrs = 0;
+
+        for (i = 0; i < MAX_MEM_CHANNELS; i++) {
+                c = data->amb_present[i];
+                for (j = 0; j < REAL_MAX_AMBS_PER_CHANNEL; j++, c >>= 1) {
+                        struct i5k_device_attribute *iattr;
+
+                        k = AMB_NUM_FROM_REG(i, j);
+                        if (!(c & 0x1))
+                                continue;
+                        d++;
+
+                        /* Temperature sysfs knob */
+                        iattr = data->attrs + data->num_attrs;
+                        snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
+                                 "temp%d_input", d);
+                        iattr->s_attr.dev_attr.attr.name = iattr->name;
+                        iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
+                        iattr->s_attr.dev_attr.show = show_amb_temp;
+                        iattr->s_attr.index = k;
+                        res = device_create_file(&pdev->dev,
+                                                 &iattr->s_attr.dev_attr);
+                        if (res)
+                                goto exit_remove;
+                        data->num_attrs++;
+
+                        /* Temperature min sysfs knob */
+                        iattr = data->attrs + data->num_attrs;
+                        snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
+                                 "temp%d_min", d);
+                        iattr->s_attr.dev_attr.attr.name = iattr->name;
+                        iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
+                        iattr->s_attr.dev_attr.show = show_amb_min;
+                        iattr->s_attr.dev_attr.store = store_amb_min;
+                        iattr->s_attr.index = k;
+                        res = device_create_file(&pdev->dev,
+                                                 &iattr->s_attr.dev_attr);
+                        if (res)
+                                goto exit_remove;
+                        data->num_attrs++;
+
+                        /* Temperature mid sysfs knob */
+                        iattr = data->attrs + data->num_attrs;
+                        snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
+                                 "temp%d_mid", d);
+                        iattr->s_attr.dev_attr.attr.name = iattr->name;
+                        iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
+                        iattr->s_attr.dev_attr.show = show_amb_mid;
+                        iattr->s_attr.dev_attr.store = store_amb_mid;
+                        iattr->s_attr.index = k;
+                        res = device_create_file(&pdev->dev,
+                                                 &iattr->s_attr.dev_attr);
+                        if (res)
+                                goto exit_remove;
+                        data->num_attrs++;
+
+                        /* Temperature max sysfs knob */
+                        iattr = data->attrs + data->num_attrs;
+                        snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
+                                 "temp%d_max", d);
+                        iattr->s_attr.dev_attr.attr.name = iattr->name;
+                        iattr->s_attr.dev_attr.attr.mode = S_IWUSR | S_IRUGO;
+                        iattr->s_attr.dev_attr.show = show_amb_max;
+                        iattr->s_attr.dev_attr.store = store_amb_max;
+                        iattr->s_attr.index = k;
+                        res = device_create_file(&pdev->dev,
+                                                 &iattr->s_attr.dev_attr);
+                        if (res)
+                                goto exit_remove;
+                        data->num_attrs++;
+
+                        /* Temperature alarm sysfs knob */
+                        iattr = data->attrs + data->num_attrs;
+                        snprintf(iattr->name, AMB_SYSFS_NAME_LEN,
+                                 "temp%d_alarm", d);
+                        iattr->s_attr.dev_attr.attr.name = iattr->name;
+                        iattr->s_attr.dev_attr.attr.mode = S_IRUGO;
+                        iattr->s_attr.dev_attr.show = show_amb_alarm;
+                        iattr->s_attr.index = k;
+                        res = device_create_file(&pdev->dev,
+                                                 &iattr->s_attr.dev_attr);
+                        if (res)
+                                goto exit_remove;
+                        data->num_attrs++;
+                }
+        }
+
+        res = device_create_file(&pdev->dev, &dev_attr_name);
+        if (res)
+                goto exit_remove;
+
+        data->hwmon_dev = hwmon_device_register(&pdev->dev);
+        if (IS_ERR(data->hwmon_dev)) {
+                res = PTR_ERR(data->hwmon_dev);
+                goto exit_remove;
+        }
+
+        return res;
+
+exit_remove:
+        device_remove_file(&pdev->dev, &dev_attr_name);
+        for (i = 0; i < data->num_attrs; i++)
+                device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
+        kfree(data->attrs);
+
+        return res;
+}
+
+static int __devinit i5k_amb_add(void)
+{
+        int res = -ENODEV;
+
+        /* only ever going to be one of these */
+        amb_pdev = platform_device_alloc(DRVNAME, 0);
+        if (!amb_pdev)
+                return -ENOMEM;
+
+        res = platform_device_add(amb_pdev);
+        if (res)
+                goto err;
+        return 0;
+
+err:
+        platform_device_put(amb_pdev);
+        return res;
+}
+
+static int __devinit i5k_find_amb_registers(struct i5k_amb_data *data)
+{
+        struct pci_dev *pcidev;
+        u32 val32;
+        int res = -ENODEV;
+
+        /* Find AMB register memory space */
+        pcidev = pci_get_device(PCI_VENDOR_ID_INTEL,
+                                PCI_DEVICE_ID_INTEL_5000_ERR,
+                                NULL);
+        if (!pcidev)
+                return -ENODEV;
+
+        if (pci_read_config_dword(pcidev, I5K_REG_AMB_BASE_ADDR, &val32))
+                goto out;
+        data->amb_base = val32;
+
+        if (pci_read_config_dword(pcidev, I5K_REG_AMB_LEN_ADDR, &val32))
+                goto out;
+        data->amb_len = val32;
+
+        /* Is it big enough? */
+        if (data->amb_len < AMB_CONFIG_SIZE * MAX_AMBS) {
+                dev_err(&pcidev->dev, "AMB region too small!\n");
+                goto out;
+        }
+
+        res = 0;
+out:
+        pci_dev_put(pcidev);
+        return res;
+}
+
+static int __devinit i5k_channel_probe(u16 *amb_present, unsigned long dev_id)
+{
+        struct pci_dev *pcidev;
+        u16 val16;
+        int res = -ENODEV;
+
+        /* Copy the DIMM presence map for these two channels */
+        pcidev = pci_get_device(PCI_VENDOR_ID_INTEL, dev_id, NULL);
+        if (!pcidev)
+                return -ENODEV;
+
+        if (pci_read_config_word(pcidev, I5K_REG_CHAN0_PRESENCE_ADDR, &val16))
+                goto out;
+        amb_present[0] = val16;
+
+        if (pci_read_config_word(pcidev, I5K_REG_CHAN1_PRESENCE_ADDR, &val16))
+                goto out;
+        amb_present[1] = val16;
+
+        res = 0;
+
+out:
+        pci_dev_put(pcidev);
+        return res;
+}
+
+static int __devinit i5k_amb_probe(struct platform_device *pdev)
+{
+        struct i5k_amb_data *data;
+        struct resource *reso;
+        int res = -ENODEV;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        /* Figure out where the AMB registers live */
+        res = i5k_find_amb_registers(data);
+        if (res)
+                goto err;
+
+        /* Copy the DIMM presence map for the first two channels */
+        res = i5k_channel_probe(&data->amb_present[0],
+                                PCI_DEVICE_ID_INTEL_5000_FBD0);
+        if (res)
+                goto err;
+
+        /* Copy the DIMM presence map for the optional second two channels */
+        i5k_channel_probe(&data->amb_present[2],
+                          PCI_DEVICE_ID_INTEL_5000_FBD1);
+
+        /* Set up resource regions */
+        reso = request_mem_region(data->amb_base, data->amb_len, DRVNAME);
+        if (!reso) {
+                res = -EBUSY;
+                goto err;
+        }
+
+        data->amb_mmio = ioremap_nocache(data->amb_base, data->amb_len);
+        if (!data->amb_mmio) {
+                res = -EBUSY;
+                goto err_map_failed;
+        }
+
+        platform_set_drvdata(pdev, data);
+
+        res = i5k_amb_hwmon_init(pdev);
+        if (res)
+                goto err_init_failed;
+
+        return res;
+
+err_init_failed:
+        iounmap(data->amb_mmio);
+        platform_set_drvdata(pdev, NULL);
+err_map_failed:
+        release_mem_region(data->amb_base, data->amb_len);
+err:
+        kfree(data);
+        return res;
+}
+
+static int __devexit i5k_amb_remove(struct platform_device *pdev)
+{
+        int i;
+        struct i5k_amb_data *data = platform_get_drvdata(pdev);
+
+        hwmon_device_unregister(data->hwmon_dev);
+        device_remove_file(&pdev->dev, &dev_attr_name);
+        for (i = 0; i < data->num_attrs; i++)
+                device_remove_file(&pdev->dev, &data->attrs[i].s_attr.dev_attr);
+        kfree(data->attrs);
+        iounmap(data->amb_mmio);
+        release_mem_region(data->amb_base, data->amb_len);
+        platform_set_drvdata(pdev, NULL);
+        kfree(data);
+        return 0;
+}
+
+static struct platform_driver i5k_amb_driver = {
+        .driver = {
+                .owner = THIS_MODULE,
+                .name = DRVNAME,
+        },
+        .probe = i5k_amb_probe,
+        .remove = __devexit_p(i5k_amb_remove),
+};
+
+static int __init i5k_amb_init(void)
+{
+        int res;
+
+        res = platform_driver_register(&i5k_amb_driver);
+        if (res)
+                return res;
+
+        res = i5k_amb_add();
+        if (res)
+                platform_driver_unregister(&i5k_amb_driver);
+
+        return res;
+}
+
+static void __exit i5k_amb_exit(void)
+{
+        platform_device_unregister(amb_pdev);
+        platform_driver_unregister(&i5k_amb_driver);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
+MODULE_DESCRIPTION("Intel 5000 chipset FB-DIMM AMB temperature sensor");
+MODULE_LICENSE("GPL");
+
+module_init(i5k_amb_init);
+module_exit(i5k_amb_exit);