[Intel-gfx] [PATCH v2 4/4] drm/i915: introduce _FIELD() to define register field values
Jani Nikula
jani.nikula at intel.com
Thu Jan 17 12:14:03 UTC 2019
Slightly verbose, but does away with hand rolled shifts. Ties the field
values with the mask defining the field.
Unfortunately we have to make a local copy of FIELD_PREP() to evaluate
to a constant expression. But with this, we can ensure the mask is
non-zero, power of 2, fits u32, and the value fits the mask (when the
value is a constant expression).
v2:
- add build-time checks with BUILD_BUG_ON_ZERO()
- rename to just _FIELD() due to regmap.h REG_FIELD() clash
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 64 +++++++++++++++++++++------------
1 file changed, 41 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 1b5cbae9c11d..a07b61cec078 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -62,8 +62,9 @@
* significant to least significant bit. Indent the register content macros
* using two extra spaces between ``#define`` and the macro name.
*
- * Define bit fields using ``_MASK(h, l)``. Define bit field contents so that
- * they are already shifted in place, and can be directly OR'd. For convenience,
+ * Define bit fields using ``_MASK(h, l)``. Define bit field contents using
+ * ``_FIELD(mask, value)``. This will define the values already shifted in
+ * place, so they can be directly OR'd together. For convenience,
* function-like macros may be used to define bit fields, but do note that the
* macros may be needed to read as well as write the register contents.
*
@@ -107,9 +108,9 @@
* #define FOO(pipe) _MMIO_PIPE(pipe, _FOO_A, _FOO_B)
* #define FOO_ENABLE _BIT(31)
* #define FOO_MODE_MASK _MASK(19, 16)
- * #define FOO_MODE_BAR (0 << 16)
- * #define FOO_MODE_BAZ (1 << 16)
- * #define FOO_MODE_QUX_SNB (2 << 16)
+ * #define FOO_MODE_BAR _FIELD(FOO_MODE_MASK, 0)
+ * #define FOO_MODE_BAZ _FIELD(FOO_MODE_MASK, 1)
+ * #define FOO_MODE_QUX_SNB _FIELD(FOO_MODE_MASK, 2)
*
* #define BAR _MMIO(0xb000)
* #define GEN8_BAR _MMIO(0xb888)
@@ -132,6 +133,23 @@
*/
#define _MASK(__high, __low) ((u32)GENMASK(__high, __low))
+#define __POWER_OF_2(x) ((x) && (((x) & ((x) - 1)) == 0))
+
+/*
+ * Macro for defining register field values. Shifts the value to the register
+ * field defined by mask.
+ *
+ * Local version of FIELD_PREP() to evaluate to an integer constant expression
+ * to allow use in e.g. case labels. Do *not* use outside of this file. Use
+ * FIELD_PREP() instead.
+ */
+#define _FIELD(__mask, __val) \
+ ((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \
+ BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
+ BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \
+ BUILD_BUG_ON_ZERO(!__POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \
+ BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0)))
+
typedef struct {
u32 reg;
} i915_reg_t;
@@ -4677,25 +4695,25 @@ enum {
*/
#define PP_READY _BIT(30)
#define PP_SEQUENCE_MASK _MASK(29, 28)
-#define PP_SEQUENCE_NONE (0 << 28)
-#define PP_SEQUENCE_POWER_UP (1 << 28)
-#define PP_SEQUENCE_POWER_DOWN (2 << 28)
+#define PP_SEQUENCE_NONE _FIELD(PP_SEQUENCE_MASK, 0)
+#define PP_SEQUENCE_POWER_UP _FIELD(PP_SEQUENCE_MASK, 1)
+#define PP_SEQUENCE_POWER_DOWN _FIELD(PP_SEQUENCE_MASK, 2)
#define PP_CYCLE_DELAY_ACTIVE _BIT(27)
#define PP_SEQUENCE_STATE_MASK _MASK(3, 0)
-#define PP_SEQUENCE_STATE_OFF_IDLE (0x0 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_1 (0x1 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_2 (0x2 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_3 (0x3 << 0)
-#define PP_SEQUENCE_STATE_ON_IDLE (0x8 << 0)
-#define PP_SEQUENCE_STATE_ON_S1_0 (0x9 << 0)
-#define PP_SEQUENCE_STATE_ON_S1_2 (0xa << 0)
-#define PP_SEQUENCE_STATE_ON_S1_3 (0xb << 0)
-#define PP_SEQUENCE_STATE_RESET (0xf << 0)
+#define PP_SEQUENCE_STATE_OFF_IDLE _FIELD(PP_SEQUENCE_STATE_MASK, 0x0)
+#define PP_SEQUENCE_STATE_OFF_S0_1 _FIELD(PP_SEQUENCE_STATE_MASK, 0x1)
+#define PP_SEQUENCE_STATE_OFF_S0_2 _FIELD(PP_SEQUENCE_STATE_MASK, 0x2)
+#define PP_SEQUENCE_STATE_OFF_S0_3 _FIELD(PP_SEQUENCE_STATE_MASK, 0x3)
+#define PP_SEQUENCE_STATE_ON_IDLE _FIELD(PP_SEQUENCE_STATE_MASK, 0x8)
+#define PP_SEQUENCE_STATE_ON_S1_0 _FIELD(PP_SEQUENCE_STATE_MASK, 0x9)
+#define PP_SEQUENCE_STATE_ON_S1_2 _FIELD(PP_SEQUENCE_STATE_MASK, 0xa)
+#define PP_SEQUENCE_STATE_ON_S1_3 _FIELD(PP_SEQUENCE_STATE_MASK, 0xb)
+#define PP_SEQUENCE_STATE_RESET _FIELD(PP_SEQUENCE_STATE_MASK, 0xf)
#define _PP_CONTROL 0x61204
#define PP_CONTROL(pps_idx) _MMIO_PPS(pps_idx, _PP_CONTROL)
#define PANEL_UNLOCK_MASK _MASK(31, 16)
-#define PANEL_UNLOCK_REGS (0xabcd << 16)
+#define PANEL_UNLOCK_REGS _FIELD(PANEL_UNLOCK_MASK, 0xabcd)
#define BXT_POWER_CYCLE_DELAY_MASK _MASK(8, 4)
#define EDP_FORCE_VDD _BIT(3)
#define EDP_BLC_ENABLE _BIT(2)
@@ -4705,11 +4723,11 @@ enum {
#define _PP_ON_DELAYS 0x61208
#define PP_ON_DELAYS(pps_idx) _MMIO_PPS(pps_idx, _PP_ON_DELAYS)
#define PANEL_PORT_SELECT_MASK _MASK(31, 30)
-#define PANEL_PORT_SELECT_LVDS (0 << 30)
-#define PANEL_PORT_SELECT_DPA (1 << 30)
-#define PANEL_PORT_SELECT_DPC (2 << 30)
-#define PANEL_PORT_SELECT_DPD (3 << 30)
-#define PANEL_PORT_SELECT_VLV(port) ((port) << 30)
+#define PANEL_PORT_SELECT_LVDS _FIELD(PANEL_PORT_SELECT_MASK, 0)
+#define PANEL_PORT_SELECT_DPA _FIELD(PANEL_PORT_SELECT_MASK, 1)
+#define PANEL_PORT_SELECT_DPC _FIELD(PANEL_PORT_SELECT_MASK, 2)
+#define PANEL_PORT_SELECT_DPD _FIELD(PANEL_PORT_SELECT_MASK, 3)
+#define PANEL_PORT_SELECT_VLV(port) _FIELD(PANEL_PORT_SELECT_MASK, port)
#define PANEL_POWER_UP_DELAY_MASK _MASK(28, 16)
#define PANEL_LIGHT_ON_DELAY_MASK _MASK(12, 0)
--
2.20.1
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