drm/i915/cx0: Add macro to get DDI port width from a register value

A follow-up change will need to retrieve the DDI port field from the
register value, add a macro for this. Make things symmetric with setting
the field in the register.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
Link: https://lore.kernel.org/r/20251117104602.2363671-8-mika.kahola@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_display_regs.h b/drivers/gpu/drm/i915/display/intel_display_regs.h
index 9d71e26a4fa274475a38c7be38995a0ee29486b7..c14d3caa73a7a3ffa86beca4b05700481c601899 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_display_regs.h
@@ -2349,8 +2349,13 @@ enum skl_power_gate {
 #define  DDI_BUF_CTL_TC_PHY_OWNERSHIP          REG_BIT(6)
 #define  DDI_A_4_LANES                         REG_BIT(4)
 #define  DDI_PORT_WIDTH_MASK                   REG_GENMASK(3, 1)
+#define  DDI_PORT_WIDTH_ENCODE(width)          ((width) == 3 ? 4 : (width) - 1)
+#define  DDI_PORT_WIDTH_DECODE(regval)         ((regval) == 4 ? 3 : (regval) + 1)
 #define  DDI_PORT_WIDTH(width)                 REG_FIELD_PREP(DDI_PORT_WIDTH_MASK, \
-                                                              ((width) == 3 ? 4 : (width) - 1))
+                                                              DDI_PORT_WIDTH_ENCODE(width))
+#define  DDI_PORT_WIDTH_GET(regval)            DDI_PORT_WIDTH_DECODE(REG_FIELD_GET(DDI_PORT_WIDTH_MASK, \
+                                                                                   (regval)))
+
 #define  DDI_PORT_WIDTH_SHIFT                  1
 #define  DDI_INIT_DISPLAY_DETECTED             REG_BIT(0)