[DPU PATCH v4 2/5] drm: add constant N value in helper file

[Vara Reddy]

From: Chandan Uddaraju <chandanu at codeaurora.org>

The constant N value (0x8000) is used by multiple DP
drivers. Define this value in header file and use this
in the existing i915 display driver.

Signed-off-by: Chandan Uddaraju <chandanu at codeaurora.org>
Signed-off-by: Vara Reddy <varar at codeaurora.org>
---
 drivers/gpu/drm/i915/display/intel_display.c | 2 +-
 include/drm/drm_dp_helper.h                  | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index effc425..3c016f3 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7618,7 +7618,7 @@ static void compute_m_n(unsigned int m, unsigned int n,
 	 * which the devices expect also in synchronous clock mode.
 	 */
 	if (constant_n)
-		*ret_n = 0x8000;
+		*ret_n = DP_LINK_CONSTANT_N_VALUE;
 	else
 		*ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
 
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 51ecb51..b509e74 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1455,6 +1455,8 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
 int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
 				 u8 status[DP_LINK_STATUS_SIZE]);
 
+#define DP_LINK_CONSTANT_N_VALUE 0x8000
+
 int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
 				const u8 port_cap[4]);
 int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
-- 
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