gpio-feature.c

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/*
 * Apple Onboard Audio feature call GPIO control
 *
 * Copyright 2006 Johannes Berg <[email protected]>
 *
 * GPL v2, can be found in COPYING.
 *
 * This file contains the GPIO control routines for
 * direct (through feature calls) access to the GPIO
 * registers.
 */

#include <asm/pmac_feature.h>
#include <linux/interrupt.h>
#include "../aoa.h"

/* TODO: these are lots of global variables
 * that aren't used on most machines...
 * Move them into a dynamically allocated
 * structure and use that.
 */

/* these are the GPIO numbers (register addresses as offsets into
 * the GPIO space) */
static int headphone_mute_gpio;
static int master_mute_gpio;
static int amp_mute_gpio;
static int lineout_mute_gpio;
static int hw_reset_gpio;
static int lineout_detect_gpio;
static int headphone_detect_gpio;
static int linein_detect_gpio;

/* see the SWITCH_GPIO macro */
static int headphone_mute_gpio_activestate;
static int master_mute_gpio_activestate;
static int amp_mute_gpio_activestate;
static int lineout_mute_gpio_activestate;
static int hw_reset_gpio_activestate;
static int lineout_detect_gpio_activestate;
static int headphone_detect_gpio_activestate;
static int linein_detect_gpio_activestate;

/* node pointers that we save when getting the GPIO number
 * to get the interrupt later */
static struct device_node *lineout_detect_node;
static struct device_node *linein_detect_node;
static struct device_node *headphone_detect_node;

static int lineout_detect_irq;
static int linein_detect_irq;
static int headphone_detect_irq;

static struct device_node *get_gpio(char *name,
                    char *altname,
                    int *gpioptr,
                    int *gpioactiveptr)
{
    struct device_node *np, *gpio;
    const u32 *reg;
    const char *audio_gpio;

    *gpioptr = -1;

    /* check if we can get it the easy way ... */
    np = of_find_node_by_name(NULL, name);
    if (!np) {
        /* some machines have only gpioX/extint-gpioX nodes,
         * and an audio-gpio property saying what it is ...
         * So what we have to do is enumerate all children
         * of the gpio node and check them all. */
        gpio = of_find_node_by_name(NULL, "gpio");
        if (!gpio)
            return NULL;
        while ((np = of_get_next_child(gpio, np))) {
            audio_gpio = of_get_property(np, "audio-gpio", NULL);
            if (!audio_gpio)
                continue;
            if (strcmp(audio_gpio, name) == 0)
                break;
            if (altname && (strcmp(audio_gpio, altname) == 0))
                break;
        }
        /* still not found, assume not there */
        if (!np)
            return NULL;
    }

    reg = of_get_property(np, "reg", NULL);
    if (!reg)
        return NULL;

    *gpioptr = *reg;

    /* this is a hack, usually the GPIOs 'reg' property
     * should have the offset based from the GPIO space
     * which is at 0x50, but apparently not always... */
    if (*gpioptr < 0x50)
        *gpioptr += 0x50;

    reg = of_get_property(np, "audio-gpio-active-state", NULL);
    if (!reg)
        /* Apple seems to default to 1, but
         * that doesn't seem right at least on most
         * machines. So until proven that the opposite
         * is necessary, we default to 0
         * (which, incidentally, snd-powermac also does...) */
        *gpioactiveptr = 0;
    else
        *gpioactiveptr = *reg;

    return np;
}

static void get_irq(struct device_node * np, int *irqptr)
{
    if (np)
        *irqptr = irq_of_parse_and_map(np, 0);
    else
        *irqptr = NO_IRQ;
}

/* 0x4 is outenable, 0x1 is out, thus 4 or 5 */
#define SWITCH_GPIO(name, v, on)                \
    (((v)&~1) | ((on)?                  \
            (name##_gpio_activestate==0?4:5):   \
            (name##_gpio_activestate==0?5:4)))

#define FTR_GPIO(name, bit)                 \
static void ftr_gpio_set_##name(struct gpio_runtime *rt, int on)\
{                               \
    int v;                          \
                                \
    if (unlikely(!rt)) return;              \
                                \
    if (name##_mute_gpio < 0)               \
        return;                     \
                                \
    v = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL,     \
                  name##_mute_gpio,         \
                  0);               \
                                \
    /* muted = !on... */                    \
    v = SWITCH_GPIO(name##_mute, v, !on);           \
                                \
    pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL,        \
              name##_mute_gpio, v);         \
                                \
    rt->implementation_private &= ~(1<<bit);        \
    rt->implementation_private |= (!!on << bit);        \
}                               \
static int ftr_gpio_get_##name(struct gpio_runtime *rt)     \
{                               \
    if (unlikely(!rt)) return 0;                \
    return (rt->implementation_private>>bit)&1;     \
}

FTR_GPIO(headphone, 0);
FTR_GPIO(amp, 1);
FTR_GPIO(lineout, 2);
FTR_GPIO(master, 3);

static void ftr_gpio_set_hw_reset(struct gpio_runtime *rt, int on)
{
    int v;

    if (unlikely(!rt)) return;
    if (hw_reset_gpio < 0)
        return;

    v = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL,
                  hw_reset_gpio, 0);
    v = SWITCH_GPIO(hw_reset, v, on);
    pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL,
              hw_reset_gpio, v);
}

static struct gpio_methods methods;

static void ftr_gpio_all_amps_off(struct gpio_runtime *rt)
{
    int saved;

    if (unlikely(!rt)) return;
    saved = rt->implementation_private;
    ftr_gpio_set_headphone(rt, 0);
    ftr_gpio_set_amp(rt, 0);
    ftr_gpio_set_lineout(rt, 0);
    if (methods.set_master)
        ftr_gpio_set_master(rt, 0);
    rt->implementation_private = saved;
}

static void ftr_gpio_all_amps_restore(struct gpio_runtime *rt)
{
    int s;

    if (unlikely(!rt)) return;
    s = rt->implementation_private;
    ftr_gpio_set_headphone(rt, (s>>0)&1);
    ftr_gpio_set_amp(rt, (s>>1)&1);
    ftr_gpio_set_lineout(rt, (s>>2)&1);
    if (methods.set_master)
        ftr_gpio_set_master(rt, (s>>3)&1);
}

static void ftr_handle_notify(struct work_struct *work)
{
    struct gpio_notification *notif =
        container_of(work, struct gpio_notification, work.work);

    mutex_lock(&notif->mutex);
    if (notif->notify)
        notif->notify(notif->data);
    mutex_unlock(&notif->mutex);
}

static void gpio_enable_dual_edge(int gpio)
{
    int v;

    if (gpio == -1)
        return;
    v = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, gpio, 0);
    v |= 0x80; /* enable dual edge */
    pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, gpio, v);
}

static void ftr_gpio_init(struct gpio_runtime *rt)
{
    get_gpio("headphone-mute", NULL,
         &headphone_mute_gpio,
         &headphone_mute_gpio_activestate);
    get_gpio("amp-mute", NULL,
         &amp_mute_gpio,
         &amp_mute_gpio_activestate);
    get_gpio("lineout-mute", NULL,
         &lineout_mute_gpio,
         &lineout_mute_gpio_activestate);
    get_gpio("hw-reset", "audio-hw-reset",
         &hw_reset_gpio,
         &hw_reset_gpio_activestate);
    if (get_gpio("master-mute", NULL,
             &master_mute_gpio,
             &master_mute_gpio_activestate)) {
        methods.set_master = ftr_gpio_set_master;
        methods.get_master = ftr_gpio_get_master;
    }

    headphone_detect_node = get_gpio("headphone-detect", NULL,
                     &headphone_detect_gpio,
                     &headphone_detect_gpio_activestate);
    /* go Apple, and thanks for giving these different names
     * across the board... */
    lineout_detect_node = get_gpio("lineout-detect", "line-output-detect",
                       &lineout_detect_gpio,
                       &lineout_detect_gpio_activestate);
    linein_detect_node = get_gpio("linein-detect", "line-input-detect",
                      &linein_detect_gpio,
                      &linein_detect_gpio_activestate);

    gpio_enable_dual_edge(headphone_detect_gpio);
    gpio_enable_dual_edge(lineout_detect_gpio);
    gpio_enable_dual_edge(linein_detect_gpio);

    get_irq(headphone_detect_node, &headphone_detect_irq);
    get_irq(lineout_detect_node, &lineout_detect_irq);
    get_irq(linein_detect_node, &linein_detect_irq);

    ftr_gpio_all_amps_off(rt);
    rt->implementation_private = 0;
    INIT_DELAYED_WORK(&rt->headphone_notify.work, ftr_handle_notify);
    INIT_DELAYED_WORK(&rt->line_in_notify.work, ftr_handle_notify);
    INIT_DELAYED_WORK(&rt->line_out_notify.work, ftr_handle_notify);
    mutex_init(&rt->headphone_notify.mutex);
    mutex_init(&rt->line_in_notify.mutex);
    mutex_init(&rt->line_out_notify.mutex);
}

static void ftr_gpio_exit(struct gpio_runtime *rt)
{
    ftr_gpio_all_amps_off(rt);
    rt->implementation_private = 0;
    if (rt->headphone_notify.notify)
        free_irq(headphone_detect_irq, &rt->headphone_notify);
    if (rt->line_in_notify.gpio_private)
        free_irq(linein_detect_irq, &rt->line_in_notify);
    if (rt->line_out_notify.gpio_private)
        free_irq(lineout_detect_irq, &rt->line_out_notify);
    cancel_delayed_work_sync(&rt->headphone_notify.work);
    cancel_delayed_work_sync(&rt->line_in_notify.work);
    cancel_delayed_work_sync(&rt->line_out_notify.work);
    mutex_destroy(&rt->headphone_notify.mutex);
    mutex_destroy(&rt->line_in_notify.mutex);
    mutex_destroy(&rt->line_out_notify.mutex);
}

static irqreturn_t ftr_handle_notify_irq(int xx, void *data)
{
    struct gpio_notification *notif = data;

    schedule_delayed_work(&notif->work, 0);

    return IRQ_HANDLED;
}

static int ftr_set_notify(struct gpio_runtime *rt,
              enum notify_type type,
              notify_func_t notify,
              void *data)
{
    struct gpio_notification *notif;
    notify_func_t old;
    int irq;
    char *name;
    int err = -EBUSY;

    switch (type) {
    case AOA_NOTIFY_HEADPHONE:
        notif = &rt->headphone_notify;
        name = "headphone-detect";
        irq = headphone_detect_irq;
        break;
    case AOA_NOTIFY_LINE_IN:
        notif = &rt->line_in_notify;
        name = "linein-detect";
        irq = linein_detect_irq;
        break;
    case AOA_NOTIFY_LINE_OUT:
        notif = &rt->line_out_notify;
        name = "lineout-detect";
        irq = lineout_detect_irq;
        break;
    default:
        return -EINVAL;
    }

    if (irq == NO_IRQ)
        return -ENODEV;

    mutex_lock(&notif->mutex);

    old = notif->notify;

    if (!old && !notify) {
        err = 0;
        goto out_unlock;
    }

    if (old && notify) {
        if (old == notify && notif->data == data)
            err = 0;
        goto out_unlock;
    }

    if (old && !notify)
        free_irq(irq, notif);

    if (!old && notify) {
        err = request_irq(irq, ftr_handle_notify_irq, 0, name, notif);
        if (err)
            goto out_unlock;
    }

    notif->notify = notify;
    notif->data = data;

    err = 0;
 out_unlock:
    mutex_unlock(&notif->mutex);
    return err;
}

static int ftr_get_detect(struct gpio_runtime *rt,
              enum notify_type type)
{
    int gpio, ret, active;

    switch (type) {
    case AOA_NOTIFY_HEADPHONE:
        gpio = headphone_detect_gpio;
        active = headphone_detect_gpio_activestate;
        break;
    case AOA_NOTIFY_LINE_IN:
        gpio = linein_detect_gpio;
        active = linein_detect_gpio_activestate;
        break;
    case AOA_NOTIFY_LINE_OUT:
        gpio = lineout_detect_gpio;
        active = lineout_detect_gpio_activestate;
        break;
    default:
        return -EINVAL;
    }

    if (gpio == -1)
        return -ENODEV;

    ret = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, gpio, 0);
    if (ret < 0)
        return ret;
    return ((ret >> 1) & 1) == active;
}

static struct gpio_methods methods = {
    .init           = ftr_gpio_init,
    .exit           = ftr_gpio_exit,
    .all_amps_off       = ftr_gpio_all_amps_off,
    .all_amps_restore   = ftr_gpio_all_amps_restore,
    .set_headphone      = ftr_gpio_set_headphone,
    .set_speakers       = ftr_gpio_set_amp,
    .set_lineout        = ftr_gpio_set_lineout,
    .set_hw_reset       = ftr_gpio_set_hw_reset,
    .get_headphone      = ftr_gpio_get_headphone,
    .get_speakers       = ftr_gpio_get_amp,
    .get_lineout        = ftr_gpio_get_lineout,
    .set_notify     = ftr_set_notify,
    .get_detect     = ftr_get_detect,
};

struct gpio_methods *ftr_gpio_methods = &methods;
EXPORT_SYMBOL_GPL(ftr_gpio_methods);