3 files changed, 282 insertions, 5 deletions

diff --git a/Documentation/hwmon/pc87427 b/Documentation/hwmon/pc87427
index db5cc1227a83..3282bf39d67d 100644
--- a/Documentation/hwmon/pc87427
+++ b/Documentation/hwmon/pc87427
@@ -20,8 +20,8 @@ The National Semiconductor Super I/O chip includes complete hardware
 monitoring capabilities. It can monitor up to 18 voltages, 8 fans and
 6 temperature sensors. Only the fans are supported at the moment.
 
-This chip also has fan controlling features, which are not yet supported
-by this driver either.
+This chip also has fan controlling features (up to 4 PWM outputs),
+which are partly supported by this driver.
 
 The driver assumes that no more than one chip is present, which seems
 reasonable.
@@ -36,3 +36,12 @@ signal. Speeds down to 83 RPM can be measured.
 An alarm is triggered if the rotation speed drops below a programmable
 limit. Another alarm is triggered if the speed is too low to be measured
 (including stalled or missing fan).
+
+
+Fan Speed Control
+-----------------
+
+Fan speed can be controlled by PWM outputs. There are 4 possible modes:
+always off, always on, manual and automatic. The latter isn't supported
+by the driver: you can only return to that mode if it was the original
+setting, and the configuration interface is missing.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d50e9fa8016f..ea3d8dff684b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -711,7 +711,8 @@ config SENSORS_PC87427
           functions of the National Semiconductor PC87427 Super-I/O chip.
           The chip has two distinct logical devices, one for fan speed
           monitoring and control, and one for voltage and temperature
-          monitoring. Only fan speed monitoring is supported right now.
+          monitoring. Only fan speed monitoring and control is supported
+          right now.
 
           This driver can also be built as a module.  If so, the module
           will be called pc87427.
diff --git a/drivers/hwmon/pc87427.c b/drivers/hwmon/pc87427.c
index 0ac55ba6c6b8..869822785b4f 100644
--- a/drivers/hwmon/pc87427.c
+++ b/drivers/hwmon/pc87427.c
@@ -15,10 +15,10 @@
  *  Supports the following chips:
  *
  *  Chip        #vin    #fan    #pwm    #temp   devid
- *  PC87427     -       8       -       -       0xF2
+ *  PC87427     -       8       4       -       0xF2
  *
  *  This driver assumes that no more than one chip is present.
- *  Only fan inputs are supported so far, although the chip can do much more.
+ *  Only fans are supported so far, although the chip can do much more.
  */
 
 #include <linux/module.h>
@@ -57,10 +57,16 @@ struct pc87427_data {
         u16 fan[8];                     /* register values */
         u16 fan_min[8];                 /* register values */
         u8 fan_status[8];               /* register values */
+
+        u8 pwm_enabled;                 /* bit vector */
+        u8 pwm_auto_ok;                 /* bit vector */
+        u8 pwm_enable[4];               /* register values */
+        u8 pwm[4];                      /* register values */
 };
 
 struct pc87427_sio_data {
         u8 has_fanin;
+        u8 has_fanout;
 };
 
 /*
@@ -72,7 +78,9 @@ struct pc87427_sio_data {
 #define SIOREG_CF2      0x22    /* Configuration 2 */
 #define SIOREG_CF3      0x23    /* Configuration 3 */
 #define SIOREG_CF4      0x24    /* Configuration 4 */
+#define SIOREG_CF5      0x25    /* Configuration 5 */
 #define SIOREG_CFB      0x2B    /* Configuration B */
+#define SIOREG_CFC      0x2C    /* Configuration C */
 #define SIOREG_CFD      0x2D    /* Configuration D */
 #define SIOREG_ACT      0x30    /* Device activation */
 #define SIOREG_MAP      0x50    /* I/O or memory mapping */
@@ -188,6 +196,61 @@ static inline u16 fan_to_reg(unsigned long val)
 }
 
 /*
+ * PWM registers and conversions
+ */
+
+#define PC87427_REG_PWM_ENABLE          0x10
+#define PC87427_REG_PWM_DUTY            0x12
+
+#define PWM_ENABLE_MODE_MASK            (7 << 4)
+#define PWM_ENABLE_CTLEN                (1 << 0)
+
+#define PWM_MODE_MANUAL                 (0 << 4)
+#define PWM_MODE_AUTO                   (1 << 4)
+#define PWM_MODE_OFF                    (2 << 4)
+#define PWM_MODE_ON                     (7 << 4)
+
+/* Dedicated function to read all registers related to a given PWM output.
+   This saves us quite a few locks and bank selections.
+   Must be called with data->lock held.
+   nr is from 0 to 3 */
+static void pc87427_readall_pwm(struct pc87427_data *data, u8 nr)
+{
+        int iobase = data->address[LD_FAN];
+
+        outb(BANK_FC(nr), iobase + PC87427_REG_BANK);
+        data->pwm_enable[nr] = inb(iobase + PC87427_REG_PWM_ENABLE);
+        data->pwm[nr] = inb(iobase + PC87427_REG_PWM_DUTY);
+}
+
+static inline int pwm_enable_from_reg(u8 reg)
+{
+        switch (reg & PWM_ENABLE_MODE_MASK) {
+        case PWM_MODE_ON:
+                return 0;
+        case PWM_MODE_MANUAL:
+        case PWM_MODE_OFF:
+                return 1;
+        case PWM_MODE_AUTO:
+                return 2;
+        default:
+                return -EPROTO;
+        }
+}
+
+static inline u8 pwm_enable_to_reg(unsigned long val, u8 pwmval)
+{
+        switch (val) {
+        default:
+                return PWM_MODE_ON;
+        case 1:
+                return pwmval ? PWM_MODE_MANUAL : PWM_MODE_OFF;
+        case 2:
+                return PWM_MODE_AUTO;
+        }
+}
+
+/*
  * Data interface
  */
 
@@ -207,6 +270,14 @@ static struct pc87427_data *pc87427_update_device(struct device *dev)
                         continue;
                 pc87427_readall_fan(data, i);
         }
+
+        /* PWM outputs */
+        for (i = 0; i < 4; i++) {
+                if (!(data->pwm_enabled & (1 << i)))
+                        continue;
+                pc87427_readall_pwm(data, i);
+        }
+
         data->last_updated = jiffies;
 
 done:
@@ -384,6 +455,145 @@ static const struct attribute_group pc87427_group_fan[8] = {
         { .attrs = pc87427_attributes_fan[7] },
 };
 
+/* Must be called with data->lock held and pc87427_readall_pwm() freshly
+   called */
+static void update_pwm_enable(struct pc87427_data *data, int nr, u8 mode)
+{
+        int iobase = data->address[LD_FAN];
+        data->pwm_enable[nr] &= ~PWM_ENABLE_MODE_MASK;
+        data->pwm_enable[nr] |= mode;
+        outb(data->pwm_enable[nr], iobase + PC87427_REG_PWM_ENABLE);
+}
+
+static ssize_t show_pwm_enable(struct device *dev, struct device_attribute
+                               *devattr, char *buf)
+{
+        struct pc87427_data *data = pc87427_update_device(dev);
+        int nr = to_sensor_dev_attr(devattr)->index;
+        int pwm_enable;
+
+        pwm_enable = pwm_enable_from_reg(data->pwm_enable[nr]);
+        if (pwm_enable < 0)
+                return pwm_enable;
+        return sprintf(buf, "%d\n", pwm_enable);
+}
+
+static ssize_t set_pwm_enable(struct device *dev, struct device_attribute
+                              *devattr, const char *buf, size_t count)
+{
+        struct pc87427_data *data = dev_get_drvdata(dev);
+        int nr = to_sensor_dev_attr(devattr)->index;
+        unsigned long val;
+
+        if (strict_strtoul(buf, 10, &val) < 0 || val > 2)
+                return -EINVAL;
+        /* Can't go to automatic mode if it isn't configured */
+        if (val == 2 && !(data->pwm_auto_ok & (1 << nr)))
+                return -EINVAL;
+
+        mutex_lock(&data->lock);
+        pc87427_readall_pwm(data, nr);
+        update_pwm_enable(data, nr, pwm_enable_to_reg(val, data->pwm[nr]));
+        mutex_unlock(&data->lock);
+
+        return count;
+}
+
+static ssize_t show_pwm(struct device *dev, struct device_attribute
+                        *devattr, char *buf)
+{
+        struct pc87427_data *data = pc87427_update_device(dev);
+        int nr = to_sensor_dev_attr(devattr)->index;
+
+        return sprintf(buf, "%d\n", (int)data->pwm[nr]);
+}
+
+static ssize_t set_pwm(struct device *dev, struct device_attribute
+                       *devattr, const char *buf, size_t count)
+{
+        struct pc87427_data *data = dev_get_drvdata(dev);
+        int nr = to_sensor_dev_attr(devattr)->index;
+        unsigned long val;
+        int iobase = data->address[LD_FAN];
+        u8 mode;
+
+        if (strict_strtoul(buf, 10, &val) < 0 || val > 0xff)
+                return -EINVAL;
+
+        mutex_lock(&data->lock);
+        pc87427_readall_pwm(data, nr);
+        mode = data->pwm_enable[nr] & PWM_ENABLE_MODE_MASK;
+        if (mode != PWM_MODE_MANUAL && mode != PWM_MODE_OFF) {
+                dev_notice(dev, "Can't set PWM%d duty cycle while not in "
+                           "manual mode\n", nr + 1);
+                mutex_unlock(&data->lock);
+                return -EPERM;
+        }
+
+        /* We may have to change the mode */
+        if (mode == PWM_MODE_MANUAL && val == 0) {
+                /* Transition from Manual to Off */
+                update_pwm_enable(data, nr, PWM_MODE_OFF);
+                mode = PWM_MODE_OFF;
+                dev_dbg(dev, "Switching PWM%d from %s to %s\n", nr + 1,
+                        "manual", "off");
+        } else if (mode == PWM_MODE_OFF && val != 0) {
+                /* Transition from Off to Manual */
+                update_pwm_enable(data, nr, PWM_MODE_MANUAL);
+                mode = PWM_MODE_MANUAL;
+                dev_dbg(dev, "Switching PWM%d from %s to %s\n", nr + 1,
+                        "off", "manual");
+        }
+
+        data->pwm[nr] = val;
+        if (mode == PWM_MODE_MANUAL)
+                outb(val, iobase + PC87427_REG_PWM_DUTY);
+        mutex_unlock(&data->lock);
+
+        return count;
+}
+
+static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
+                          show_pwm_enable, set_pwm_enable, 0);
+static SENSOR_DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO,
+                          show_pwm_enable, set_pwm_enable, 1);
+static SENSOR_DEVICE_ATTR(pwm3_enable, S_IWUSR | S_IRUGO,
+                          show_pwm_enable, set_pwm_enable, 2);
+static SENSOR_DEVICE_ATTR(pwm4_enable, S_IWUSR | S_IRUGO,
+                          show_pwm_enable, set_pwm_enable, 3);
+
+static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 0);
+static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
+static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 2);
+static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 3);
+
+static struct attribute *pc87427_attributes_pwm[4][3] = {
+        {
+                &sensor_dev_attr_pwm1_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm1.dev_attr.attr,
+                NULL
+        }, {
+                &sensor_dev_attr_pwm2_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm2.dev_attr.attr,
+                NULL
+        }, {
+                &sensor_dev_attr_pwm3_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm3.dev_attr.attr,
+                NULL
+        }, {
+                &sensor_dev_attr_pwm4_enable.dev_attr.attr,
+                &sensor_dev_attr_pwm4.dev_attr.attr,
+                NULL
+        }
+};
+
+static const struct attribute_group pc87427_group_pwm[4] = {
+        { .attrs = pc87427_attributes_pwm[0] },
+        { .attrs = pc87427_attributes_pwm[1] },
+        { .attrs = pc87427_attributes_pwm[2] },
+        { .attrs = pc87427_attributes_pwm[3] },
+};
+
 static ssize_t show_name(struct device *dev, struct device_attribute
                          *devattr, char *buf)
 {
@@ -431,6 +641,25 @@ static void __devinit pc87427_init_device(struct device *dev)
                 }
                 data->fan_enabled = sio_data->has_fanin;
         }
+
+        /* Check which PWM outputs are enabled */
+        for (i = 0; i < 4; i++) {
+                if (!(sio_data->has_fanout & (1 << i))) /* Not wired */
+                        continue;
+                reg = pc87427_read8_bank(data, LD_FAN, BANK_FC(i),
+                                         PC87427_REG_PWM_ENABLE);
+                if (reg & PWM_ENABLE_CTLEN)
+                        data->pwm_enabled |= (1 << i);
+
+                /* We don't expose an interface to reconfigure the automatic
+                   fan control mode, so only allow to return to this mode if
+                   it was originally set. */
+                if ((reg & PWM_ENABLE_MODE_MASK) == PWM_MODE_AUTO) {
+                        dev_dbg(dev, "PWM%d is in automatic control mode\n",
+                                i + 1);
+                        data->pwm_auto_ok |= (1 << i);
+                }
+        }
 }
 
 static int __devinit pc87427_probe(struct platform_device *pdev)
@@ -474,6 +703,14 @@ static int __devinit pc87427_probe(struct platform_device *pdev)
                 if (err)
                         goto exit_remove_files;
         }
+        for (i = 0; i < 4; i++) {
+                if (!(data->pwm_enabled & (1 << i)))
+                        continue;
+                err = sysfs_create_group(&pdev->dev.kobj,
+                                         &pc87427_group_pwm[i]);
+                if (err)
+                        goto exit_remove_files;
+        }
 
         data->hwmon_dev = hwmon_device_register(&pdev->dev);
         if (IS_ERR(data->hwmon_dev)) {
@@ -490,6 +727,11 @@ exit_remove_files:
                         continue;
                 sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_fan[i]);
         }
+        for (i = 0; i < 4; i++) {
+                if (!(data->pwm_enabled & (1 << i)))
+                        continue;
+                sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_pwm[i]);
+        }
 exit_release_region:
         release_region(res->start, resource_size(res));
 exit_kfree:
@@ -512,6 +754,11 @@ static int __devexit pc87427_remove(struct platform_device *pdev)
                         continue;
                 sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_fan[i]);
         }
+        for (i = 0; i < 4; i++) {
+                if (!(data->pwm_enabled & (1 << i)))
+                        continue;
+                sysfs_remove_group(&pdev->dev.kobj, &pc87427_group_pwm[i]);
+        }
         platform_set_drvdata(pdev, NULL);
         kfree(data);
 
@@ -648,6 +895,26 @@ static int __init pc87427_find(int sioaddr, unsigned short *address,
         if ((cfg & (1 << 3)) && !(cfg_b & (1 << 5)))
                 sio_data->has_fanin |= (1 << 6);        /* FANIN6 */
 
+        /* Check which fan outputs are wired */
+        sio_data->has_fanout = (1 << 0);                /* FANOUT0 */
+        if (cfg_b & (1 << 0))
+                sio_data->has_fanout |= (1 << 3);       /* FANOUT3 */
+
+        cfg = superio_inb(sioaddr, SIOREG_CFC);
+        if (!(cfg & (1 << 4))) {
+                if (cfg_b & (1 << 1))
+                        sio_data->has_fanout |= (1 << 1); /* FANOUT1 */
+                if (cfg_b & (1 << 2))
+                        sio_data->has_fanout |= (1 << 2); /* FANOUT2 */
+        }
+
+        /* FANOUT1 and FANOUT2 can each be routed to 2 different pins */
+        cfg = superio_inb(sioaddr, SIOREG_CF5);
+        if (cfg & (1 << 6))
+                sio_data->has_fanout |= (1 << 1);       /* FANOUT1 */
+        if (cfg & (1 << 5))
+                sio_data->has_fanout |= (1 << 2);       /* FANOUT2 */
+
 exit:
         superio_exit(sioaddr);
         return err;