ALSA: als4000 - Code clean up

- use specs-derived register name enums instead of open-coded numeric
values, for better understanding of things
- fix naming confusion ("gcr" was _NOT_ the GCR register stuff, but
  instead the io _base_ which has multiplexed _access_ to GCR config
  space, at _sub_ registers 0x08 and 0x0c)
- add FIXME comments about a race condition and MPU401 features
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/pci/als4000.c

@@ -60,6 +60,7 @@
  *
  * ToDo:
  * - Proper shared IRQ handling?
+ * - by default, don't enable legacy game and use PCI game I/O
  * - power management? (card can do voice wakeup according to datasheet!!)
  */
 
@@ -107,7 +108,7 @@ MODULE_PARM_DESC(joystick_port, "Joystick port address for ALS4000 soundcard. (0
 
 struct snd_card_als4000 {
 	/* most frequent access first */
-	unsigned long gcr;
+	unsigned long iobase;
 	struct pci_dev *pci;
 	struct snd_sb *chip;
 #ifdef SUPPORT_JOYSTICK
@@ -122,24 +123,89 @@ static struct pci_device_id snd_als4000_ids[] = {
 
 MODULE_DEVICE_TABLE(pci, snd_als4000_ids);
 
-static inline void snd_als4000_gcr_write_addr(unsigned long port, u32 reg, u32 val)
+enum als4k_iobase_t {
+	/* IOx: B == Byte, W = Word, D = DWord */
+	ALS4K_IOD_00_AC97_ACCESS = 0x00,
+	ALS4K_IOW_04_AC97_READ = 0x04,
+	ALS4K_IOB_06_AC97_STATUS = 0x06,
+	ALS4K_IOB_07_IRQSTATUS = 0x07,
+	ALS4K_IOD_08_GCR_DATA = 0x08,
+	ALS4K_IOB_0C_GCR_INDEX = 0x0c,
+	ALS4K_IOB_0E_SB_MPU_IRQ = 0x0e,
+	ALS4K_IOB_10_ADLIB_ADDR0 = 0x10,
+	ALS4K_IOB_11_ADLIB_ADDR1 = 0x11,
+	ALS4K_IOB_12_ADLIB_ADDR2 = 0x12,
+	ALS4K_IOB_13_ADLIB_ADDR3 = 0x13,
+	ALS4K_IOB_14_MIXER_INDEX = 0x14,
+	ALS4K_IOB_15_MIXER_DATA = 0x15,
+	ALS4K_IOB_16_ESP_RST_PORT = 0x16,
+	ALS4K_IOB_16_CR1E_ACK_PORT = 0x16, /* 2nd function */
+	ALS4K_IOB_18_OPL_ADDR0 = 0x18,
+	ALS4K_IOB_19_OPL_ADDR1 = 0x19,
+	ALS4K_IOB_1A_ESP_RD_DATA = 0x1a,
+	ALS4K_IOB_1C_ESP_CMD_DATA = 0x1c,
+	ALS4K_IOB_1C_ESP_WR_STATUS = 0x1c, /* 2nd function */
+	ALS4K_IOB_1E_ESP_RD_STATUS8 = 0x1e,
+	ALS4K_IOB_1F_ESP_RD_STATUS16 = 0x1f,
+	ALS4K_IOB_20_ESP_GAMEPORT_200 = 0x20,
+	ALS4K_IOB_21_ESP_GAMEPORT_201 = 0x21,
+	ALS4K_IOB_30_MIDI_DATA = 0x30,
+	ALS4K_IOB_31_MIDI_STATUS = 0x31,
+	ALS4K_IOB_31_MIDI_COMMAND = 0x31, /* 2nd function */
+};
+
+enum als4k_gcr_t {
+	/* all registers 32bit wide */
+	ALS4K_GCR_8C_MISC_CTRL = 0x8c,
+	ALS4K_GCR_90_TEST_MODE_REG = 0x90,
+	ALS4K_GCR_91_DMA0_ADDR = 0x91,
+	ALS4K_GCR_92_DMA0_MODE_COUNT = 0x92,
+	ALS4K_GCR_93_DMA1_ADDR = 0x93,
+	ALS4K_GCR_94_DMA1_MODE_COUNT = 0x94,
+	ALS4K_GCR_95_DMA3_ADDR = 0x95,
+	ALS4K_GCR_96_DMA3_MODE_COUNT = 0x96,
+	ALS4K_GCR_99_DMA_EMULATION_CTRL = 0x99,
+	ALS4K_GCR_A0_FIFO1_CURRENT_ADDR = 0xa0,
+	ALS4K_GCR_A1_FIFO1_STATUS_BYTECOUNT = 0xa1,
+	ALS4K_GCR_A2_FIFO2_PCIADDR = 0xa2,
+	ALS4K_GCR_A3_FIFO2_COUNT = 0xa3,
+	ALS4K_GCR_A4_FIFO2_CURRENT_ADDR = 0xa4,
+	ALS4K_GCR_A5_FIFO1_STATUS_BYTECOUNT = 0xa5,
+	ALS4K_GCR_A6_PM_CTRL = 0xa6,
+	ALS4K_GCR_A7_PCI_ACCESS_STORAGE = 0xa7,
+	ALS4K_GCR_A8_LEGACY_CFG1 = 0xa8,
+	ALS4K_GCR_A9_LEGACY_CFG2 = 0xa9,
+	ALS4K_GCR_FF_DUMMY_SCRATCH = 0xff,
+};
+
+enum als4k_gcr_8c_t {
+	ALS4K_GCR_8C_IRQ_MASK_CTRL_ENABLE = 0x8000,
+	ALS4K_GCR_8C_CHIP_REV_MASK = 0xf0000
+};
+
+static inline void snd_als4000_gcr_write_addr(unsigned long iobase,
+						 enum als4k_gcr_t reg,
+						 u32 val)
 {
-	outb(reg, port+0x0c);
-	outl(val, port+0x08);
+	outb(reg, iobase + ALS4K_IOB_0C_GCR_INDEX);
+	outl(val, iobase + ALS4K_IOD_08_GCR_DATA);
 }
 
-static inline void snd_als4000_gcr_write(struct snd_sb *sb, u32 reg, u32 val)
+static inline void snd_als4000_gcr_write(struct snd_sb *sb,
+						 enum als4k_gcr_t reg,
+						 u32 val)
 {
 	snd_als4000_gcr_write_addr(sb->alt_port, reg, val);
 }	
 
-static inline u32 snd_als4000_gcr_read_addr(unsigned long port, u32 reg)
+static inline u32 snd_als4000_gcr_read_addr(unsigned long iobase,
+						 enum als4k_gcr_t reg)
 {
-	outb(reg, port+0x0c);
-	return inl(port+0x08);
+	outb(reg, iobase + ALS4K_IOB_0C_GCR_INDEX);
+	return inl(iobase + ALS4K_IOD_08_GCR_DATA);
 }
 
-static inline u32 snd_als4000_gcr_read(struct snd_sb *sb, u32 reg)
+static inline u32 snd_als4000_gcr_read(struct snd_sb *sb, enum als4k_gcr_t reg)
 {
 	return snd_als4000_gcr_read_addr(sb->alt_port, reg);
 }
@@ -156,15 +222,17 @@ static void snd_als4000_set_rate(struct snd_sb *chip, unsigned int rate)
 static inline void snd_als4000_set_capture_dma(struct snd_sb *chip,
 					       dma_addr_t addr, unsigned size)
 {
-	snd_als4000_gcr_write(chip, 0xa2, addr);
-	snd_als4000_gcr_write(chip, 0xa3, (size-1));
+	snd_als4000_gcr_write(chip, ALS4K_GCR_A2_FIFO2_PCIADDR, addr);
+	snd_als4000_gcr_write(chip, ALS4K_GCR_A3_FIFO2_COUNT, (size-1));
 }
 
 static inline void snd_als4000_set_playback_dma(struct snd_sb *chip,
-						dma_addr_t addr, unsigned size)
+						dma_addr_t addr,
+						unsigned size)
 {
-	snd_als4000_gcr_write(chip, 0x91, addr);
-	snd_als4000_gcr_write(chip, 0x92, (size-1)|0x180000);
+	snd_als4000_gcr_write(chip, ALS4K_GCR_91_DMA0_ADDR, addr);
+	snd_als4000_gcr_write(chip, ALS4K_GCR_92_DMA0_MODE_COUNT,
+							(size-1)|0x180000);
 }
 
 #define ALS4000_FORMAT_SIGNED	(1<<0)
@@ -305,6 +373,12 @@ static int snd_als4000_capture_trigger(struct snd_pcm_substream *substream, int
 	struct snd_sb *chip = snd_pcm_substream_chip(substream);
 	int result = 0;
 	
+	/* FIXME race condition in here!!!
+	   chip->mode non-atomic update gets consistently protected
+	   by reg_lock always, _except_ for this place!!
+	   Probably need to take reg_lock as outer (or inner??) lock, too.
+	   (or serialize both lock operations? probably not, though... - racy?)
+	*/
 	spin_lock(&chip->mixer_lock);
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
@@ -356,7 +430,8 @@ static snd_pcm_uframes_t snd_als4000_capture_pointer(struct snd_pcm_substream *s
 	unsigned int result;
 
 	spin_lock(&chip->reg_lock);	
-	result = snd_als4000_gcr_read(chip, 0xa4) & 0xffff;
+	result = snd_als4000_gcr_read(chip, ALS4K_GCR_A4_FIFO2_CURRENT_ADDR);
+	result &= 0xffff;
 	spin_unlock(&chip->reg_lock);
 	return bytes_to_frames( substream->runtime, result );
 }
@@ -367,7 +442,8 @@ static snd_pcm_uframes_t snd_als4000_playback_pointer(struct snd_pcm_substream *
 	unsigned result;
 
 	spin_lock(&chip->reg_lock);	
-	result = snd_als4000_gcr_read(chip, 0xa0) & 0xffff;
+	result = snd_als4000_gcr_read(chip, ALS4K_GCR_A0_FIFO1_CURRENT_ADDR);
+	result &= 0xffff;
 	spin_unlock(&chip->reg_lock);
 	return bytes_to_frames( substream->runtime, result );
 }
@@ -376,12 +452,13 @@ static snd_pcm_uframes_t snd_als4000_playback_pointer(struct snd_pcm_substream *
  * return IRQ_HANDLED no matter whether we actually had an IRQ flag or not).
  * ALS4000a.PDF writes that while ACKing IRQ in PCI block will *not* ACK
  * the IRQ in the SB core, ACKing IRQ in SB block *will* ACK the PCI IRQ
- * register (alt_port + 0x0e). Probably something could be optimized here to
- * query/write one register only...
+ * register (alt_port + ALS4K_IOB_0E_SB_MPU_IRQ). Probably something
+ * could be optimized here to query/write one register only...
  * And even if both registers need to be queried, then there's still the
  * question of whether it's actually correct to ACK PCI IRQ before reading
  * SB IRQ like we do now, since ALS4000a.PDF mentions that PCI IRQ will *clear*
  * SB IRQ status.
+ * (hmm, page 38 mentions it the other way around!)
  * And do we *really* need the lock here for *reading* SB_DSP4_IRQSTATUS??
  * */
 static irqreturn_t snd_als4000_interrupt(int irq, void *dev_id)
@@ -391,7 +468,7 @@ static irqreturn_t snd_als4000_interrupt(int irq, void *dev_id)
 	unsigned sb_status;
 
 	/* find out which bit of the ALS4000 produced the interrupt */
-	gcr_status = inb(chip->alt_port + 0xe);
+	gcr_status = inb(chip->alt_port + ALS4K_IOB_0E_SB_MPU_IRQ);
 
 	if ((gcr_status & 0x80) && (chip->playback_substream)) /* playback */
 		snd_pcm_period_elapsed(chip->playback_substream);
@@ -400,7 +477,7 @@ static irqreturn_t snd_als4000_interrupt(int irq, void *dev_id)
 	if ((gcr_status & 0x10) && (chip->rmidi)) /* MPU401 interrupt */
 		snd_mpu401_uart_interrupt(irq, chip->rmidi->private_data);
 	/* release the gcr */
-	outb(gcr_status, chip->alt_port + 0xe);
+	outb(gcr_status, chip->alt_port + ALS4K_IOB_0E_SB_MPU_IRQ);
 	
 	spin_lock(&chip->mixer_lock);
 	sb_status = snd_sbmixer_read(chip, SB_DSP4_IRQSTATUS);
@@ -543,25 +620,25 @@ static int __devinit snd_als4000_pcm(struct snd_sb *chip, int device)
 
 /******************************************************************/
 
-static void snd_als4000_set_addr(unsigned long gcr,
-					unsigned int sb,
-					unsigned int mpu,
-					unsigned int opl,
-					unsigned int game)
+static void snd_als4000_set_addr(unsigned long iobase,
+					unsigned int sb_io,
+					unsigned int mpu_io,
+					unsigned int opl_io,
+					unsigned int game_io)
 {
-	u32 confA = 0;
-	u32 confB = 0;
+	u32 cfg1 = 0;
+	u32 cfg2 = 0;
 
-	if (mpu > 0)
-		confB |= (mpu | 1) << 16;
-	if (sb > 0)
-		confB |= (sb | 1);
-	if (game > 0)
-		confA |= (game | 1) << 16;
-	if (opl > 0)	
-		confA |= (opl | 1);
-	snd_als4000_gcr_write_addr(gcr, 0xa8, confA);
-	snd_als4000_gcr_write_addr(gcr, 0xa9, confB);
+	if (mpu_io > 0)
+		cfg2 |= (mpu_io | 1) << 16;
+	if (sb_io > 0)
+		cfg2 |= (sb_io | 1);
+	if (game_io > 0)
+		cfg1 |= (game_io | 1) << 16;
+	if (opl_io > 0)
+		cfg1 |= (opl_io | 1);
+	snd_als4000_gcr_write_addr(iobase, ALS4K_GCR_A8_LEGACY_CFG1, cfg1);
+	snd_als4000_gcr_write_addr(iobase, ALS4K_GCR_A9_LEGACY_CFG2, cfg2);
 }
 
 static void snd_als4000_configure(struct snd_sb *chip)
@@ -579,12 +656,15 @@ static void snd_als4000_configure(struct snd_sb *chip)
 	spin_unlock_irq(&chip->mixer_lock);
 	
 	spin_lock_irq(&chip->reg_lock);
-	/* magic number. Enables interrupts(?) */
-	snd_als4000_gcr_write(chip, 0x8c, 0x28000);
-	for(i = 0x91; i <= 0x96; ++i)
+	/* enable interrupts */
+	snd_als4000_gcr_write(chip, ALS4K_GCR_8C_MISC_CTRL,
+					 ALS4K_GCR_8C_IRQ_MASK_CTRL_ENABLE);
+
+	for (i = ALS4K_GCR_91_DMA0_ADDR; i <= ALS4K_GCR_96_DMA3_MODE_COUNT; ++i)
 		snd_als4000_gcr_write(chip, i, 0);
 	
-	snd_als4000_gcr_write(chip, 0x99, snd_als4000_gcr_read(chip, 0x99));
+	snd_als4000_gcr_write(chip, ALS4K_GCR_99_DMA_EMULATION_CTRL,
+		snd_als4000_gcr_read(chip, ALS4K_GCR_99_DMA_EMULATION_CTRL));
 	spin_unlock_irq(&chip->reg_lock);
 }
 
@@ -628,7 +708,7 @@ static int __devinit snd_als4000_create_gameport(struct snd_card_als4000 *acard,
 	gameport_set_port_data(gp, r);
 
 	/* Enable legacy joystick port */
-	snd_als4000_set_addr(acard->gcr, 0, 0, 0, 1);
+	snd_als4000_set_addr(acard->iobase, 0, 0, 0, 1);
 
 	gameport_register_port(acard->gameport);
 
@@ -643,7 +723,9 @@ static void snd_als4000_free_gameport(struct snd_card_als4000 *acard)
 		gameport_unregister_port(acard->gameport);
 		acard->gameport = NULL;
 
-		snd_als4000_set_addr(acard->gcr, 0, 0, 0, 0); /* disable joystick */
+		/* disable joystick */
+		snd_als4000_set_addr(acard->iobase, 0, 0, 0, 0);
+
 		release_and_free_resource(r);
 	}
 }
@@ -654,10 +736,10 @@ static inline void snd_als4000_free_gameport(struct snd_card_als4000 *acard) { }
 
 static void snd_card_als4000_free( struct snd_card *card )
 {
-	struct snd_card_als4000 * acard = (struct snd_card_als4000 *)card->private_data;
+	struct snd_card_als4000 *acard = card->private_data;
 
 	/* make sure that interrupts are disabled */
-	snd_als4000_gcr_write_addr( acard->gcr, 0x8c, 0);
+	snd_als4000_gcr_write_addr(acard->iobase, ALS4K_GCR_8C_MISC_CTRL, 0);
 	/* free resources */
 	snd_als4000_free_gameport(acard);
 	pci_release_regions(acard->pci);
@@ -670,7 +752,7 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 	static int dev;
 	struct snd_card *card;
 	struct snd_card_als4000 *acard;
-	unsigned long gcr;
+	unsigned long iobase;
 	struct snd_sb *chip;
 	struct snd_opl3 *opl3;
 	unsigned short word;
@@ -699,7 +781,7 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 		pci_disable_device(pci);
 		return err;
 	}
-	gcr = pci_resource_start(pci, 0);
+	iobase = pci_resource_start(pci, 0);
 
 	pci_read_config_word(pci, PCI_COMMAND, &word);
 	pci_write_config_word(pci, PCI_COMMAND, word | PCI_COMMAND_IO);
@@ -713,16 +795,16 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 		return -ENOMEM;
 	}
 
-	acard = (struct snd_card_als4000 *)card->private_data;
+	acard = card->private_data;
 	acard->pci = pci;
-	acard->gcr = gcr;
+	acard->iobase = iobase;
 	card->private_free = snd_card_als4000_free;
 
 	/* disable all legacy ISA stuff */
-	snd_als4000_set_addr(acard->gcr, 0, 0, 0, 0);
+	snd_als4000_set_addr(acard->iobase, 0, 0, 0, 0);
 
 	if ((err = snd_sbdsp_create(card,
-				    gcr + 0x10,
+				    iobase + ALS4K_IOB_10_ADLIB_ADDR0,
 				    pci->irq,
 				    snd_als4000_interrupt,
 				    -1,
@@ -734,7 +816,7 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 	acard->chip = chip;
 
 	chip->pci = pci;
-	chip->alt_port = gcr;
+	chip->alt_port = iobase;
 	snd_card_set_dev(card, &pci->dev);
 
 	snd_als4000_configure(chip);
@@ -745,11 +827,16 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 		card->shortname, chip->alt_port, chip->irq);
 
 	if ((err = snd_mpu401_uart_new( card, 0, MPU401_HW_ALS4000,
-				        gcr+0x30, MPU401_INFO_INTEGRATED,
+					iobase + ALS4K_IOB_30_MIDI_DATA,
+					MPU401_INFO_INTEGRATED,
 					pci->irq, 0, &chip->rmidi)) < 0) {
-		printk(KERN_ERR "als4000: no MPU-401 device at 0x%lx?\n", gcr+0x30);
+		printk(KERN_ERR "als4000: no MPU-401 device at 0x%lx?\n",
+				iobase + ALS4K_IOB_30_MIDI_DATA);
 		goto out_err;
 	}
+	/* FIXME: ALS4000 has interesting MPU401 configuration features
+	 * at CR 0x1A (pass-thru / UART switching, fast MIDI clock, etc.),
+	 * however there doesn't seem to be an ALSA API for this... */
 
 	if ((err = snd_als4000_pcm(chip, 0)) < 0) {
 		goto out_err;
@@ -758,10 +845,13 @@ static int __devinit snd_card_als4000_probe(struct pci_dev *pci,
 		goto out_err;
 	}	    
 
-	if (snd_opl3_create(card, gcr+0x10, gcr+0x12,
+	if (snd_opl3_create(card,
+				iobase + ALS4K_IOB_10_ADLIB_ADDR0,
+				iobase + ALS4K_IOB_12_ADLIB_ADDR2,
 			    OPL3_HW_AUTO, 1, &opl3) < 0) {
 		printk(KERN_ERR "als4000: no OPL device at 0x%lx-0x%lx?\n",
-			   gcr+0x10, gcr+0x12 );
+			   iobase + ALS4K_IOB_10_ADLIB_ADDR0,
+			   iobase + ALS4K_IOB_12_ADLIB_ADDR2);
 	} else {
 		if ((err = snd_opl3_hwdep_new(opl3, 0, 1, NULL)) < 0) {
 			goto out_err;
@@ -831,13 +921,13 @@ static int snd_als4000_resume(struct pci_dev *pci)
 
 #ifdef SUPPORT_JOYSTICK
 	if (acard->gameport)
-		snd_als4000_set_addr(acard->gcr, 0, 0, 0, 1);
+		snd_als4000_set_addr(acard->iobase, 0, 0, 0, 1);
 #endif
 
 	snd_power_change_state(card, SNDRV_CTL_POWER_D0);
 	return 0;
 }
-#endif
+#endif /* CONFIG_PM */
 
 
 static struct pci_driver driver = {