windfarm_smu_controls.c

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/*
 * Windfarm PowerMac thermal control. SMU based controls
 *
 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
 *                    <[email protected]>
 *
 * Released under the term of the GNU GPL v2.
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/completion.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/sections.h>
#include <asm/smu.h>

#include "windfarm.h"

#define VERSION "0.4"

#undef DEBUG

#ifdef DEBUG
#define DBG(args...)    printk(args)
#else
#define DBG(args...)    do { } while(0)
#endif

static int smu_supports_new_fans_ops = 1;

/*
 * SMU fans control object
 */

static LIST_HEAD(smu_fans);

struct smu_fan_control {
    struct list_head    link;
    int             fan_type;   /* 0 = rpm, 1 = pwm */
    u32         reg;        /* index in SMU */
    s32         value;      /* current value */
    s32         min, max;   /* min/max values */
    struct wf_control   ctrl;
};
#define to_smu_fan(c) container_of(c, struct smu_fan_control, ctrl)

static int smu_set_fan(int pwm, u8 id, u16 value)
{
    struct smu_cmd cmd;
    u8 buffer[16];
    DECLARE_COMPLETION_ONSTACK(comp);
    int rc;

    /* Fill SMU command structure */
    cmd.cmd = SMU_CMD_FAN_COMMAND;

    /* The SMU has an "old" and a "new" way of setting the fan speed
     * Unfortunately, I found no reliable way to know which one works
     * on a given machine model. After some investigations it appears
     * that MacOS X just tries the new one, and if it fails fallbacks
     * to the old ones ... Ugh.
     */
 retry:
    if (smu_supports_new_fans_ops) {
        buffer[0] = 0x30;
        buffer[1] = id;
        *((u16 *)(&buffer[2])) = value;
        cmd.data_len = 4;
    } else {
        if (id > 7)
            return -EINVAL;
        /* Fill argument buffer */
        memset(buffer, 0, 16);
        buffer[0] = pwm ? 0x10 : 0x00;
        buffer[1] = 0x01 << id;
        *((u16 *)&buffer[2 + id * 2]) = value;
        cmd.data_len = 14;
    }

    cmd.reply_len = 16;
    cmd.data_buf = cmd.reply_buf = buffer;
    cmd.status = 0;
    cmd.done = smu_done_complete;
    cmd.misc = &comp;

    rc = smu_queue_cmd(&cmd);
    if (rc)
        return rc;
    wait_for_completion(&comp);

    /* Handle fallback (see coment above) */
    if (cmd.status != 0 && smu_supports_new_fans_ops) {
        printk(KERN_WARNING "windfarm: SMU failed new fan command "
               "falling back to old method\n");
        smu_supports_new_fans_ops = 0;
        goto retry;
    }

    return cmd.status;
}

static void smu_fan_release(struct wf_control *ct)
{
    struct smu_fan_control *fct = to_smu_fan(ct);

    kfree(fct);
}

static int smu_fan_set(struct wf_control *ct, s32 value)
{
    struct smu_fan_control *fct = to_smu_fan(ct);

    if (value < fct->min)
        value = fct->min;
    if (value > fct->max)
        value = fct->max;
    fct->value = value;

    return smu_set_fan(fct->fan_type, fct->reg, value);
}

static int smu_fan_get(struct wf_control *ct, s32 *value)
{
    struct smu_fan_control *fct = to_smu_fan(ct);
    *value = fct->value; /* todo: read from SMU */
    return 0;
}

static s32 smu_fan_min(struct wf_control *ct)
{
    struct smu_fan_control *fct = to_smu_fan(ct);
    return fct->min;
}

static s32 smu_fan_max(struct wf_control *ct)
{
    struct smu_fan_control *fct = to_smu_fan(ct);
    return fct->max;
}

static struct wf_control_ops smu_fan_ops = {
    .set_value  = smu_fan_set,
    .get_value  = smu_fan_get,
    .get_min    = smu_fan_min,
    .get_max    = smu_fan_max,
    .release    = smu_fan_release,
    .owner      = THIS_MODULE,
};

static struct smu_fan_control *smu_fan_create(struct device_node *node,
                          int pwm_fan)
{
    struct smu_fan_control *fct;
    const s32 *v;
    const u32 *reg;
    const char *l;

    fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
    if (fct == NULL)
        return NULL;
    fct->ctrl.ops = &smu_fan_ops;
    l = of_get_property(node, "location", NULL);
    if (l == NULL)
        goto fail;

    fct->fan_type = pwm_fan;
    fct->ctrl.type = pwm_fan ? WF_CONTROL_PWM_FAN : WF_CONTROL_RPM_FAN;

    /* We use the name & location here the same way we do for SMU sensors,
     * see the comment in windfarm_smu_sensors.c. The locations are a bit
     * less consistent here between the iMac and the desktop models, but
     * that is good enough for our needs for now at least.
     *
     * One problem though is that Apple seem to be inconsistent with case
     * and the kernel doesn't have strcasecmp =P
     */

    fct->ctrl.name = NULL;

    /* Names used on desktop models */
    if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
        !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
        !strcmp(l, "CPU A EXHAUST"))
        fct->ctrl.name = "cpu-rear-fan-0";
    else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
         !strcmp(l, "CPU B EXHAUST"))
        fct->ctrl.name = "cpu-rear-fan-1";
    else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
         !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
         !strcmp(l, "CPU A INTAKE"))
        fct->ctrl.name = "cpu-front-fan-0";
    else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
         !strcmp(l, "CPU B INTAKE"))
        fct->ctrl.name = "cpu-front-fan-1";
    else if (!strcmp(l, "CPU A PUMP"))
        fct->ctrl.name = "cpu-pump-0";
    else if (!strcmp(l, "CPU B PUMP"))
        fct->ctrl.name = "cpu-pump-1";
    else if (!strcmp(l, "Slots Fan") || !strcmp(l, "Slots fan") ||
         !strcmp(l, "EXPANSION SLOTS INTAKE"))
        fct->ctrl.name = "slots-fan";
    else if (!strcmp(l, "Drive Bay") || !strcmp(l, "Drive bay") ||
         !strcmp(l, "DRIVE BAY A INTAKE"))
        fct->ctrl.name = "drive-bay-fan";
    else if (!strcmp(l, "BACKSIDE"))
        fct->ctrl.name = "backside-fan";

    /* Names used on iMac models */
    if (!strcmp(l, "System Fan") || !strcmp(l, "System fan"))
        fct->ctrl.name = "system-fan";
    else if (!strcmp(l, "CPU Fan") || !strcmp(l, "CPU fan"))
        fct->ctrl.name = "cpu-fan";
    else if (!strcmp(l, "Hard Drive") || !strcmp(l, "Hard drive"))
        fct->ctrl.name = "drive-bay-fan";
    else if (!strcmp(l, "HDD Fan")) /* seen on iMac G5 iSight */
        fct->ctrl.name = "hard-drive-fan";
    else if (!strcmp(l, "ODD Fan")) /* same */
        fct->ctrl.name = "optical-drive-fan";

    /* Unrecognized fan, bail out */
    if (fct->ctrl.name == NULL)
        goto fail;

    /* Get min & max values*/
    v = of_get_property(node, "min-value", NULL);
    if (v == NULL)
        goto fail;
    fct->min = *v;
    v = of_get_property(node, "max-value", NULL);
    if (v == NULL)
        goto fail;
    fct->max = *v;

    /* Get "reg" value */
    reg = of_get_property(node, "reg", NULL);
    if (reg == NULL)
        goto fail;
    fct->reg = *reg;

    if (wf_register_control(&fct->ctrl))
        goto fail;

    return fct;
 fail:
    kfree(fct);
    return NULL;
}


static int __init smu_controls_init(void)
{
    struct device_node *smu, *fans, *fan;

    if (!smu_present())
        return -ENODEV;

    smu = of_find_node_by_type(NULL, "smu");
    if (smu == NULL)
        return -ENODEV;

    /* Look for RPM fans */
    for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
        if (!strcmp(fans->name, "rpm-fans") ||
            of_device_is_compatible(fans, "smu-rpm-fans"))
            break;
    for (fan = NULL;
         fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
        struct smu_fan_control *fct;

        fct = smu_fan_create(fan, 0);
        if (fct == NULL) {
            printk(KERN_WARNING "windfarm: Failed to create SMU "
                   "RPM fan %s\n", fan->name);
            continue;
        }
        list_add(&fct->link, &smu_fans);
    }
    of_node_put(fans);


    /* Look for PWM fans */
    for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
        if (!strcmp(fans->name, "pwm-fans"))
            break;
    for (fan = NULL;
         fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
        struct smu_fan_control *fct;

        fct = smu_fan_create(fan, 1);
        if (fct == NULL) {
            printk(KERN_WARNING "windfarm: Failed to create SMU "
                   "PWM fan %s\n", fan->name);
            continue;
        }
        list_add(&fct->link, &smu_fans);
    }
    of_node_put(fans);
    of_node_put(smu);

    return 0;
}

static void __exit smu_controls_exit(void)
{
    struct smu_fan_control *fct;

    while (!list_empty(&smu_fans)) {
        fct = list_entry(smu_fans.next, struct smu_fan_control, link);
        list_del(&fct->link);
        wf_unregister_control(&fct->ctrl);
    }
}


module_init(smu_controls_init);
module_exit(smu_controls_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <[email protected]>");
MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
MODULE_LICENSE("GPL");