ALSA: hda: Direct MMIO accesses

HD-audio drivers access to the mmio registers indirectly via the
corresponding bus->io_ops callbacks.  This is because some platform
(notably Tegra SoC) requires the word-aligned access.  But it's rather
a rare case, and other platforms suffer from the penalties by indirect
calls unnecessarily.

This patch is an attempt to optimize and cleanup for this situation.
Now the special aligned access is used only when a new kconfig
CONFIG_SND_HDA_ALIGNED_MMIO is set.  And the HD-audio core itself
provides the aligned MMIO access helpers instead of the driver side.
If Kconfig isn't set (as default), the standard helpers like readl()
or writel() are used directly.

A couple of places in ASoC Intel drivers have the access via io_ops
reg_writel(), and they are replaced with the direct writel() calls.

And now with this patch, the whole bus->io_ops becomes empty, so it's
dropped completely.  The bus initialization functions are changed
accordingly as well to drop the whole bus->io_ops.

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 1 insertions, 67 deletions

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index ba414cc639f1..8350954b7986 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -75,72 +75,6 @@ MODULE_PARM_DESC(power_save,
 #define power_save	0
 #endif
 
-/*
- * Register access ops. Tegra HDA register access is DWORD only.
- */
-static void hda_tegra_writel(u32 value, u32 __iomem *addr)
-{
-	writel(value, addr);
-}
-
-static u32 hda_tegra_readl(u32 __iomem *addr)
-{
-	return readl(addr);
-}
-
-static void hda_tegra_writew(u16 value, u16 __iomem  *addr)
-{
-	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
-	void __iomem *dword_addr = (void __iomem *)((unsigned long)(addr) & ~0x3);
-	u32 v;
-
-	v = readl(dword_addr);
-	v &= ~(0xffff << shift);
-	v |= value << shift;
-	writel(v, dword_addr);
-}
-
-static u16 hda_tegra_readw(u16 __iomem *addr)
-{
-	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
-	void __iomem *dword_addr = (void __iomem *)((unsigned long)(addr) & ~0x3);
-	u32 v;
-
-	v = readl(dword_addr);
-	return (v >> shift) & 0xffff;
-}
-
-static void hda_tegra_writeb(u8 value, u8 __iomem *addr)
-{
-	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
-	void __iomem *dword_addr = (void __iomem *)((unsigned long)(addr) & ~0x3);
-	u32 v;
-
-	v = readl(dword_addr);
-	v &= ~(0xff << shift);
-	v |= value << shift;
-	writel(v, dword_addr);
-}
-
-static u8 hda_tegra_readb(u8 __iomem *addr)
-{
-	unsigned int shift = ((unsigned long)(addr) & 0x3) << 3;
-	void __iomem *dword_addr = (void __iomem *)((unsigned long)(addr) & ~0x3);
-	u32 v;
-
-	v = readl(dword_addr);
-	return (v >> shift) & 0xff;
-}
-
-static const struct hdac_io_ops hda_tegra_io_ops = {
-	.reg_writel = hda_tegra_writel,
-	.reg_readl = hda_tegra_readl,
-	.reg_writew = hda_tegra_writew,
-	.reg_readw = hda_tegra_readw,
-	.reg_writeb = hda_tegra_writeb,
-	.reg_readb = hda_tegra_readb,
-};
-
 static const struct hda_controller_ops hda_tegra_ops; /* nothing special */
 
 static void hda_tegra_init(struct hda_tegra *hda)
@@ -459,7 +393,7 @@ static int hda_tegra_create(struct snd_card *card,
 
 	INIT_WORK(&hda->probe_work, hda_tegra_probe_work);
 
-	err = azx_bus_init(chip, NULL, &hda_tegra_io_ops);
+	err = azx_bus_init(chip, NULL);
 	if (err < 0)
 		return err;