[PATCH v2 4/6] drm/i915/bios: Extract intel_spi_read16()

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The SPI VBT codepath only knows how to read 4 bytes at a time.
So to read the 2 byte vbt_size it masks out the unwanted msbs.
Hide that little implementation detail inside a new intel_spi_read16()
helper. Alse rename the existing intel_spi_read() to intel_spi_read32()
to make it clear what it does.

Reviewed-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index d4281234773c..38ea92b4ff13 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -3053,13 +3053,18 @@ static struct vbt_header *firmware_get_vbt(struct intel_display *display,
 	return vbt;
 }
 
-static u32 intel_spi_read(struct intel_uncore *uncore, u32 offset)
+static u32 intel_spi_read32(struct intel_uncore *uncore, u32 offset)
 {
 	intel_uncore_write(uncore, PRIMARY_SPI_ADDRESS, offset);
 
 	return intel_uncore_read(uncore, PRIMARY_SPI_TRIGGER);
 }
 
+static u16 intel_spi_read16(struct intel_uncore *uncore, u32 offset)
+{
+	return intel_spi_read32(uncore, offset) & 0xffff;
+}
+
 static struct vbt_header *spi_oprom_get_vbt(struct intel_display *display,
 					    size_t *size)
 {
@@ -3078,7 +3083,7 @@ static struct vbt_header *spi_oprom_get_vbt(struct intel_display *display,
 	oprom_offset &= OROM_OFFSET_MASK;
 
 	for (count = 0; count < oprom_size; count += 4) {
-		data = intel_spi_read(&i915->uncore, oprom_offset + count);
+		data = intel_spi_read32(&i915->uncore, oprom_offset + count);
 		if (data == *((const u32 *)"$VBT")) {
 			found = oprom_offset + count;
 			break;
@@ -3094,9 +3099,8 @@ static struct vbt_header *spi_oprom_get_vbt(struct intel_display *display,
 	}
 
 	/* Get VBT size and allocate space for the VBT */
-	vbt_size = intel_spi_read(&i915->uncore,
-				  found + offsetof(struct vbt_header, vbt_size));
-	vbt_size &= 0xffff;
+	vbt_size = intel_spi_read16(&i915->uncore,
+				    found + offsetof(struct vbt_header, vbt_size));
 
 	if (vbt_size > oprom_size - count) {
 		drm_dbg_kms(display->drm,
@@ -3109,7 +3113,7 @@ static struct vbt_header *spi_oprom_get_vbt(struct intel_display *display,
 		goto err_not_found;
 
 	for (count = 0; count < vbt_size; count += 4)
-		*(vbt + store++) = intel_spi_read(&i915->uncore, found + count);
+		*(vbt + store++) = intel_spi_read32(&i915->uncore, found + count);
 
 	if (!intel_bios_is_valid_vbt(display, vbt, vbt_size))
 		goto err_free_vbt;
-- 
2.44.2