[ALSA] protect Dreamcast PCM driver (AICA) from G2 bus effects
[linux-2.6.git] / sound / sh / aica.c
index 97bb86a..88dc840 100644 (file)
@@ -64,12 +64,6 @@ module_param(enable, bool, 0644);
 MODULE_PARM_DESC(enable, "Enable " CARD_NAME " soundcard.");
 
 /* Use workqueue */
-
-static struct spu_work_holder {
-       struct work_struct spu_dma_work;
-       void *sspointer;
-} spu_working;
-
 static struct workqueue_struct *aica_queue;
 
 /* Simple platform device */
@@ -100,9 +94,9 @@ static void spu_write_wait(void)
                        break;
                /* To ensure hardware failure doesn't wedge kernel */
                time_count++;
-               if (time_count > 0x10000)
-               {
-                       snd_printk("WARNING: G2 FIFO appears to be blocked.\n");
+               if (time_count > 0x10000) {
+                       snd_printk
+                           ("WARNING: G2 FIFO appears to be blocked.\n");
                        break;
                }
        }
@@ -112,11 +106,14 @@ static void spu_write_wait(void)
 static void spu_memset(u32 toi, u32 what, int length)
 {
        int i;
+       unsigned long flags;
        snd_assert(length % 4 == 0, return);
        for (i = 0; i < length; i++) {
                if (!(i % 8))
                        spu_write_wait();
+               local_irq_save(flags);
                writel(what, toi + SPU_MEMORY_BASE);
+               local_irq_restore(flags);
                toi++;
        }
 }
@@ -124,6 +121,7 @@ static void spu_memset(u32 toi, u32 what, int length)
 /* spu_memload - write to SPU address space */
 static void spu_memload(u32 toi, void *from, int length)
 {
+       unsigned long flags;
        u32 *froml = from;
        u32 __iomem *to = (u32 __iomem *) (SPU_MEMORY_BASE + toi);
        int i;
@@ -134,7 +132,9 @@ static void spu_memload(u32 toi, void *from, int length)
                if (!(i % 8))
                        spu_write_wait();
                val = *froml;
+               local_irq_save(flags);
                writel(val, to);
+               local_irq_restore(flags);
                froml++;
                to++;
        }
@@ -144,28 +144,36 @@ static void spu_memload(u32 toi, void *from, int length)
 static void spu_disable(void)
 {
        int i;
+       unsigned long flags;
        u32 regval;
        spu_write_wait();
        regval = readl(ARM_RESET_REGISTER);
        regval |= 1;
        spu_write_wait();
+       local_irq_save(flags);
        writel(regval, ARM_RESET_REGISTER);
+       local_irq_restore(flags);
        for (i = 0; i < 64; i++) {
                spu_write_wait();
                regval = readl(SPU_REGISTER_BASE + (i * 0x80));
                regval = (regval & ~0x4000) | 0x8000;
                spu_write_wait();
+               local_irq_save(flags);
                writel(regval, SPU_REGISTER_BASE + (i * 0x80));
+               local_irq_restore(flags);
        }
 }
 
 /* spu_enable - set spu registers to enable sound output */
 static void spu_enable(void)
 {
+       unsigned long flags;
        u32 regval = readl(ARM_RESET_REGISTER);
        regval &= ~1;
        spu_write_wait();
+       local_irq_save(flags);
        writel(regval, ARM_RESET_REGISTER);
+       local_irq_restore(flags);
 }
 
 /* 
@@ -174,25 +182,34 @@ static void spu_enable(void)
 */
 static void spu_reset(void)
 {
+       unsigned long flags;
        spu_disable();
        spu_memset(0, 0, 0x200000 / 4);
        /* Put ARM7 in endless loop */
+       local_irq_save(flags);
        ctrl_outl(0xea000002, SPU_MEMORY_BASE);
+       local_irq_restore(flags);
        spu_enable();
 }
 
 /* aica_chn_start - write to spu to start playback */
 static void aica_chn_start(void)
 {
+       unsigned long flags;
        spu_write_wait();
+       local_irq_save(flags);
        writel(AICA_CMD_KICK | AICA_CMD_START, (u32 *) AICA_CONTROL_POINT);
+       local_irq_restore(flags);
 }
 
 /* aica_chn_halt - write to spu to halt playback */
 static void aica_chn_halt(void)
 {
+       unsigned long flags;
        spu_write_wait();
+       local_irq_save(flags);
        writel(AICA_CMD_KICK | AICA_CMD_STOP, (u32 *) AICA_CONTROL_POINT);
+       local_irq_restore(flags);
 }
 
 /* ALSA code below */
@@ -219,24 +236,28 @@ static int aica_dma_transfer(int channels, int buffer_size,
        int q, err, period_offset;
        struct snd_card_aica *dreamcastcard;
        struct snd_pcm_runtime *runtime;
-       err = 0;
+       unsigned long flags;
        dreamcastcard = substream->pcm->private_data;
        period_offset = dreamcastcard->clicks;
        period_offset %= (AICA_PERIOD_NUMBER / channels);
        runtime = substream->runtime;
        for (q = 0; q < channels; q++) {
+               local_irq_save(flags);
                err = dma_xfer(AICA_DMA_CHANNEL,
-                              (unsigned long)(runtime->dma_area +
-                                              (AICA_BUFFER_SIZE * q) /
-                                              channels +
-                                              AICA_PERIOD_SIZE *
-                                              period_offset),
+                              (unsigned long) (runtime->dma_area +
+                                               (AICA_BUFFER_SIZE * q) /
+                                               channels +
+                                               AICA_PERIOD_SIZE *
+                                               period_offset),
                               AICA_CHANNEL0_OFFSET + q * CHANNEL_OFFSET +
                               AICA_PERIOD_SIZE * period_offset,
                               buffer_size / channels, AICA_DMA_MODE);
-               if (unlikely(err < 0))
+               if (unlikely(err < 0)) {
+                       local_irq_restore(flags);
                        break;
+               }
                dma_wait_for_completion(AICA_DMA_CHANNEL);
+               local_irq_restore(flags);
        }
        return err;
 }
@@ -244,26 +265,25 @@ static int aica_dma_transfer(int channels, int buffer_size,
 static void startup_aica(struct snd_card_aica *dreamcastcard)
 {
        spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,
-                   dreamcastcard->channel,
-                   sizeof(struct aica_channel));
+                   dreamcastcard->channel, sizeof(struct aica_channel));
        aica_chn_start();
 }
 
 static void run_spu_dma(struct work_struct *work)
 {
        int buffer_size;
-       struct snd_pcm_substream *substream;
        struct snd_pcm_runtime *runtime;
        struct snd_card_aica *dreamcastcard;
-       struct spu_work_holder *holder = container_of(work, struct spu_work_holder, spu_dma_work);
-       substream = holder-> sspointer;
-       dreamcastcard = substream->pcm->private_data;
-       runtime = substream->runtime;
+       dreamcastcard =
+           container_of(work, struct snd_card_aica, spu_dma_work);
+       runtime = dreamcastcard->substream->runtime;
        if (unlikely(dreamcastcard->dma_check == 0)) {
-               buffer_size = frames_to_bytes(runtime, runtime->buffer_size);
+               buffer_size =
+                   frames_to_bytes(runtime, runtime->buffer_size);
                if (runtime->channels > 1)
                        dreamcastcard->channel->flags |= 0x01;
-               aica_dma_transfer(runtime->channels, buffer_size, substream);
+               aica_dma_transfer(runtime->channels, buffer_size,
+                                 dreamcastcard->substream);
                startup_aica(dreamcastcard);
                dreamcastcard->clicks =
                    buffer_size / (AICA_PERIOD_SIZE * runtime->channels);
@@ -271,13 +291,11 @@ static void run_spu_dma(struct work_struct *work)
        } else {
                aica_dma_transfer(runtime->channels,
                                  AICA_PERIOD_SIZE * runtime->channels,
-                                 substream);
+                                 dreamcastcard->substream);
                snd_pcm_period_elapsed(dreamcastcard->substream);
                dreamcastcard->clicks++;
                if (unlikely(dreamcastcard->clicks >= AICA_PERIOD_NUMBER))
-               {
                        dreamcastcard->clicks %= AICA_PERIOD_NUMBER;
-               }
                mod_timer(&dreamcastcard->timer, jiffies + 1);
        }
 }
@@ -289,7 +307,7 @@ static void aica_period_elapsed(unsigned long timer_var)
        struct snd_pcm_runtime *runtime;
        struct snd_pcm_substream *substream;
        struct snd_card_aica *dreamcastcard;
-       substream = (struct snd_pcm_substream *)timer_var;
+       substream = (struct snd_pcm_substream *) timer_var;
        runtime = substream->runtime;
        dreamcastcard = substream->pcm->private_data;
        /* Have we played out an additional period? */
@@ -307,27 +325,24 @@ static void aica_period_elapsed(unsigned long timer_var)
                dreamcastcard->current_period = play_period;
        if (unlikely(dreamcastcard->dma_check == 0))
                dreamcastcard->dma_check = 1;
-               queue_work(aica_queue, &(spu_working.spu_dma_work));
+       queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
 }
 
 static void spu_begin_dma(struct snd_pcm_substream *substream)
 {
-       /* Must be atomic */
        struct snd_card_aica *dreamcastcard;
        struct snd_pcm_runtime *runtime;
        runtime = substream->runtime;
        dreamcastcard = substream->pcm->private_data;
-       /*  Use queue to do the heavy lifting */
-       spu_working.sspointer = substream;
-       INIT_WORK(&(spu_working.spu_dma_work), run_spu_dma);
-       queue_work(aica_queue, &(spu_working.spu_dma_work));
+       /*get the queue to do the work */
+       queue_work(aica_queue, &(dreamcastcard->spu_dma_work));
        /* Timer may already be running */
        if (unlikely(dreamcastcard->timer.data)) {
                mod_timer(&dreamcastcard->timer, jiffies + 4);
                return;
        }
        init_timer(&(dreamcastcard->timer));
-       dreamcastcard->timer.data = (unsigned long)substream;
+       dreamcastcard->timer.data = (unsigned long) substream;
        dreamcastcard->timer.function = aica_period_elapsed;
        dreamcastcard->timer.expires = jiffies + 4;
        add_timer(&(dreamcastcard->timer));
@@ -366,7 +381,9 @@ static int snd_aicapcm_pcm_close(struct snd_pcm_substream
                                 *substream)
 {
        struct snd_card_aica *dreamcastcard = substream->pcm->private_data;
-       del_timer(&dreamcastcard->timer);
+       flush_workqueue(aica_queue);
+       if (dreamcastcard->timer.data)
+               del_timer(&dreamcastcard->timer);
        kfree(dreamcastcard->channel);
        spu_disable();
        return 0;
@@ -385,7 +402,8 @@ static int snd_aicapcm_pcm_hw_params(struct snd_pcm_substream
 {
        /* Allocate a DMA buffer using ALSA built-ins */
        return
-           snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params));
+           snd_pcm_lib_malloc_pages(substream,
+                                    params_buffer_bytes(hw_params));
 }
 
 static int snd_aicapcm_pcm_prepare(struct snd_pcm_substream
@@ -402,15 +420,11 @@ static int snd_aicapcm_pcm_prepare(struct snd_pcm_substream
 static int snd_aicapcm_pcm_trigger(struct snd_pcm_substream
                                   *substream, int cmd)
 {
-       struct snd_card_aica *dreamcastcard;
        switch (cmd) {
        case SNDRV_PCM_TRIGGER_START:
                spu_begin_dma(substream);
                break;
        case SNDRV_PCM_TRIGGER_STOP:
-               dreamcastcard = substream->pcm->private_data;
-               if (dreamcastcard->timer.data)
-                       del_timer(&dreamcastcard->timer);
                aica_chn_halt();
                break;
        default:
@@ -444,7 +458,8 @@ static int __init snd_aicapcmchip(struct snd_card_aica
        int err;
        /* AICA has no capture ability */
        err =
-           snd_pcm_new(dreamcastcard->card, "AICA PCM", pcm_index, 1, 0, &pcm);
+           snd_pcm_new(dreamcastcard->card, "AICA PCM", pcm_index, 1, 0,
+                       &pcm);
        if (unlikely(err < 0))
                return err;
        pcm->private_data = dreamcastcard;
@@ -463,15 +478,7 @@ static int __init snd_aicapcmchip(struct snd_card_aica
 }
 
 /* Mixer controls */
-static int aica_pcmswitch_info(struct snd_kcontrol *kcontrol,
-                              struct snd_ctl_elem_info *uinfo)
-{
-       uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
-       uinfo->count = 1;
-       uinfo->value.integer.min = 0;
-       uinfo->value.integer.max = 1;
-       return 0;
-}
+#define aica_pcmswitch_info            snd_ctl_boolean_mono_info
 
 static int aica_pcmswitch_get(struct snd_kcontrol *kcontrol,
                              struct snd_ctl_elem_value *ucontrol)
@@ -524,9 +531,7 @@ static int aica_pcmvolume_put(struct snd_kcontrol *kcontrol,
        dreamcastcard->channel->vol = ucontrol->value.integer.value[0];
        dreamcastcard->master_volume = ucontrol->value.integer.value[0];
        spu_memload(AICA_CHANNEL0_CONTROL_OFFSET,
-                   dreamcastcard->channel,
-                   sizeof(struct aica_channel));
-
+                   dreamcastcard->channel, sizeof(struct aica_channel));
        return 1;
 }
 
@@ -610,6 +615,8 @@ static int __init snd_aica_probe(struct platform_device *devptr)
        strcpy(dreamcastcard->card->shortname, SND_AICA_DRIVER);
        strcpy(dreamcastcard->card->longname,
               "Yamaha AICA Super Intelligent Sound Processor for SEGA Dreamcast");
+       /* Prepare to use the queue */
+       INIT_WORK(&(dreamcastcard->spu_dma_work), run_spu_dma);
        /* Load the PCM 'chip' */
        err = snd_aicapcmchip(dreamcastcard, 0);
        if (unlikely(err < 0))
@@ -663,8 +670,10 @@ static int __init aica_init(void)
 
 static void __exit aica_exit(void)
 {
-       /* Destroy the aica kernel thread */
-       destroy_workqueue(aica_queue);
+       /* Destroy the aica kernel thread            *
+        * being extra cautious to check if it exists*/
+       if (likely(aica_queue))
+               destroy_workqueue(aica_queue);
        platform_device_unregister(pd);
        platform_driver_unregister(&snd_aica_driver);
        /* Kill any sound still playing and reset ARM7 to safe state */