drm/i915/bios: add helper for reading SPI

Add helper for reading SPI to not duplicate the write&read combo
everywhere.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230512111446.1524038-1-jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 64eb11a452659ca9c6b32a496d7dda185ea6fd0c..34a397adbd6b05529d6182d27c782081a3b68e43 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -3033,6 +3033,13 @@ bool intel_bios_is_valid_vbt(const void *buf, size_t size)
        return vbt;
 }
 
+static u32 intel_spi_read(struct intel_uncore *uncore, u32 offset)
+{
+       intel_uncore_write(uncore, PRIMARY_SPI_ADDRESS, offset);
+
+       return intel_uncore_read(uncore, PRIMARY_SPI_TRIGGER);
+}
+
 static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
 {
        u32 count, data, found, store = 0;
@@ -3049,9 +3056,7 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
        oprom_offset &= OROM_OFFSET_MASK;
 
        for (count = 0; count < oprom_size; count += 4) {
-               intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, oprom_offset + count);
-               data = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
-
+               data = intel_spi_read(&i915->uncore, oprom_offset + count);
                if (data == *((const u32 *)"$VBT")) {
                        found = oprom_offset + count;
                        break;
@@ -3062,20 +3067,16 @@ static struct vbt_header *spi_oprom_get_vbt(struct drm_i915_private *i915)
                goto err_not_found;
 
        /* Get VBT size and allocate space for the VBT */
-       intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, found +
-                  offsetof(struct vbt_header, vbt_size));
-       vbt_size = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
+       vbt_size = intel_spi_read(&i915->uncore,
+                                 found + offsetof(struct vbt_header, vbt_size));
        vbt_size &= 0xffff;
 
        vbt = kzalloc(round_up(vbt_size, 4), GFP_KERNEL);
        if (!vbt)
                goto err_not_found;
 
-       for (count = 0; count < vbt_size; count += 4) {
-               intel_uncore_write(&i915->uncore, PRIMARY_SPI_ADDRESS, found + count);
-               data = intel_uncore_read(&i915->uncore, PRIMARY_SPI_TRIGGER);
-               *(vbt + store++) = data;
-       }
+       for (count = 0; count < vbt_size; count += 4)
+               *(vbt + store++) = intel_spi_read(&i915->uncore, found + count);
 
        if (!intel_bios_is_valid_vbt(vbt, vbt_size))
                goto err_free_vbt;