Introduce REG_BIT(n) to define register bits and REG_GENMASK(h, l) to
define register bitfield masks.
We define the above as wrappers to BIT() and GENMASK() respectively to
force u32 type to go with our register size, and to add compile time
checks on the bit numbers.
The intention is that these are easier to get right and review against
the spec than hand rolled masks.
Convert power sequencer registers as an example.
v4:
- rebase
v3:
- rename macros to REG_BIT() and REG_GENMASK() to avoid underscore
prefix and to be in line with kernel macros (Chris)
- add compile time checks (Mika)
v2:
- rename macros to just _BIT() and _MASK() to reduce verbosity
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_reg.h | 94 +++++++++++++++++++++------------
1 file changed, 61 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9b69cec21f7b..4a025e3c49c4 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -25,6 +25,8 @@
#ifndef _I915_REG_H_
#define _I915_REG_H_
+#include <linux/bits.h>
+
/**
* DOC: The i915 register macro definition style guide
*
@@ -59,15 +61,13 @@
* significant to least significant bit. Indent the register content macros
* using two extra spaces between ``#define`` and the macro name.
*
- * For bit fields, define a ``_MASK`` and a ``_SHIFT`` macro. Define bit field
- * contents so that they are already shifted in place, and can be directly
- * OR'd. 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.
+ * For bit fields, define a ``_MASK`` and a ``_SHIFT`` macro. Use
+ * ``REG_GENMASK()`` to define _MASK. Define bit field contents so that they are
+ * already shifted in place, and can be directly OR'd. 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.
*
- * Define bits using ``(1 << N)`` instead of ``BIT(N)``. We may change this in
- * the future, but this is the prevailing style. Do **not** add ``_BIT`` suffix
- * to the name.
+ * Define bits using ``REG_BIT(N)``. Do **not** add ``_BIT`` suffix to the name.
*
* Group the register and its contents together without blank lines, separate
* from other registers and their contents with one blank line.
@@ -105,8 +105,8 @@
* #define _FOO_A 0xf000
* #define _FOO_B 0xf001
* #define FOO(pipe) _MMIO_PIPE(pipe, _FOO_A, _FOO_B)
- * #define FOO_ENABLE (1 << 31)
- * #define FOO_MODE_MASK (0xf << 16)
+ * #define FOO_ENABLE REG_BIT(31)
+ * #define FOO_MODE_MASK REG_GENMASK(19, 16)
* #define FOO_MODE_SHIFT 16
* #define FOO_MODE_BAR (0 << 16)
* #define FOO_MODE_BAZ (1 << 16)
@@ -116,6 +116,34 @@
* #define GEN8_BAR _MMIO(0xb888)
*/
+/**
+ * REG_BIT() - Prepare a u32 bit value
+ * @__n: 0-based bit number
+ *
+ * Local wrapper for BIT() to force u32, with compile time checks.
+ *
+ * @return: Value with bit @__n set.
+ */
+#define REG_BIT(__n) \
+ ((u32)(BIT(__n) + \
+ BUILD_BUG_ON_ZERO(__builtin_constant_p(__n) && \
+ ((__n) < 0 || (__n) > 31))))
+
+/**
+ * REG_GENMASK() - Prepare a continuous u32 bitmask
+ * @__high: 0-based high bit
+ * @__low: 0-based low bit
+ *
+ * Local wrapper for GENMASK() to force u32, with compile time checks.
+ *
+ * @return: Continuous bitmask from @__high to @__low, inclusive.
+ */
+#define REG_GENMASK(__high, __low) \
+ ((u32)(GENMASK(__high, __low) + \
+ BUILD_BUG_ON_ZERO(__builtin_constant_p(__high) && \
+ __builtin_constant_p(__low) && \
+ ((__low) < 0 || (__high) > 31 || (__low) > (__high)))))
+
typedef struct {
u32 reg;
} i915_reg_t;
@@ -4692,18 +4720,18 @@ enum {
#define _PP_STATUS 0x61200
#define PP_STATUS(pps_idx) _MMIO_PPS(pps_idx, _PP_STATUS)
-#define PP_ON (1 << 31)
+#define PP_ON REG_BIT(31)
#define _PP_CONTROL_1 0xc7204
#define _PP_CONTROL_2 0xc7304
#define ICP_PP_CONTROL(x) _MMIO(((x) == 1) ? _PP_CONTROL_1 : \
_PP_CONTROL_2)
-#define POWER_CYCLE_DELAY_MASK (0x1f << 4)
+#define POWER_CYCLE_DELAY_MASK REG_GENMASK(8, 4)
#define POWER_CYCLE_DELAY_SHIFT 4
-#define VDD_OVERRIDE_FORCE (1 << 3)
-#define BACKLIGHT_ENABLE (1 << 2)
-#define PWR_DOWN_ON_RESET (1 << 1)
-#define PWR_STATE_TARGET (1 << 0)
+#define VDD_OVERRIDE_FORCE REG_BIT(3)
+#define BACKLIGHT_ENABLE REG_BIT(2)
+#define PWR_DOWN_ON_RESET REG_BIT(1)
+#define PWR_STATE_TARGET REG_BIT(0)
/*
* Indicates that all dependencies of the panel are on:
*
@@ -4711,14 +4739,14 @@ enum {
* - pipe enabled
* - LVDS/DVOB/DVOC on
*/
-#define PP_READY (1 << 30)
+#define PP_READY REG_BIT(30)
+#define PP_SEQUENCE_MASK REG_GENMASK(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_MASK (3 << 28)
#define PP_SEQUENCE_SHIFT 28
-#define PP_CYCLE_DELAY_ACTIVE (1 << 27)
-#define PP_SEQUENCE_STATE_MASK 0x0000000f
+#define PP_CYCLE_DELAY_ACTIVE REG_BIT(27)
+#define PP_SEQUENCE_STATE_MASK REG_GENMASK(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)
@@ -4731,41 +4759,41 @@ enum {
#define _PP_CONTROL 0x61204
#define PP_CONTROL(pps_idx) _MMIO_PPS(pps_idx, _PP_CONTROL)
+#define PANEL_UNLOCK_MASK REG_GENMASK(31, 16)
#define PANEL_UNLOCK_REGS (0xabcd << 16)
-#define PANEL_UNLOCK_MASK (0xffff << 16)
-#define BXT_POWER_CYCLE_DELAY_MASK 0x1f0
+#define BXT_POWER_CYCLE_DELAY_MASK REG_GENMASK(8, 4)
#define BXT_POWER_CYCLE_DELAY_SHIFT 4
-#define EDP_FORCE_VDD (1 << 3)
-#define EDP_BLC_ENABLE (1 << 2)
-#define PANEL_POWER_RESET (1 << 1)
-#define PANEL_POWER_ON (1 << 0)
+#define EDP_FORCE_VDD REG_BIT(3)
+#define EDP_BLC_ENABLE REG_BIT(2)
+#define PANEL_POWER_RESET REG_BIT(1)
+#define PANEL_POWER_ON REG_BIT(0)
#define _PP_ON_DELAYS 0x61208
#define PP_ON_DELAYS(pps_idx) _MMIO_PPS(pps_idx, _PP_ON_DELAYS)
#define PANEL_PORT_SELECT_SHIFT 30
-#define PANEL_PORT_SELECT_MASK (3 << 30)
+#define PANEL_PORT_SELECT_MASK REG_GENMASK(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_POWER_UP_DELAY_MASK 0x1fff0000
+#define PANEL_POWER_UP_DELAY_MASK REG_GENMASK(28, 16)
#define PANEL_POWER_UP_DELAY_SHIFT 16
-#define PANEL_LIGHT_ON_DELAY_MASK 0x1fff
+#define PANEL_LIGHT_ON_DELAY_MASK REG_GENMASK(12, 0)
#define PANEL_LIGHT_ON_DELAY_SHIFT 0
#define _PP_OFF_DELAYS 0x6120C
#define PP_OFF_DELAYS(pps_idx) _MMIO_PPS(pps_idx, _PP_OFF_DELAYS)
-#define PANEL_POWER_DOWN_DELAY_MASK 0x1fff0000
+#define PANEL_POWER_DOWN_DELAY_MASK REG_GENMASK(28, 16)
#define PANEL_POWER_DOWN_DELAY_SHIFT 16
-#define PANEL_LIGHT_OFF_DELAY_MASK 0x1fff
+#define PANEL_LIGHT_OFF_DELAY_MASK REG_GENMASK(12, 0)
#define PANEL_LIGHT_OFF_DELAY_SHIFT 0
#define _PP_DIVISOR 0x61210
#define PP_DIVISOR(pps_idx) _MMIO_PPS(pps_idx, _PP_DIVISOR)
-#define PP_REFERENCE_DIVIDER_MASK 0xffffff00
+#define PP_REFERENCE_DIVIDER_MASK REG_GENMASK(31, 8)
#define PP_REFERENCE_DIVIDER_SHIFT 8
-#define PANEL_POWER_CYCLE_DELAY_MASK 0x1f
+#define PANEL_POWER_CYCLE_DELAY_MASK REG_GENMASK(4, 0)
#define PANEL_POWER_CYCLE_DELAY_SHIFT 0
/* Panel fitting */
--
2.20.1
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