Make the code more robust and improve readability by using bitfield
macros instead of open coding bit operations.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_disp_aal.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_disp_aal.c b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
index e2e4155faf01..05790b444e17 100644
--- a/drivers/gpu/drm/mediatek/mtk_disp_aal.c
+++ b/drivers/gpu/drm/mediatek/mtk_disp_aal.c
@@ -18,6 +18,8 @@
 #define DISP_AAL_EN				0x0000
 #define AAL_EN						BIT(0)
 #define DISP_AAL_SIZE				0x0030
+#define DISP_AAL_SIZE_HSIZE				GENMASK(28, 16)
+#define DISP_AAL_SIZE_VSIZE				GENMASK(12, 0)
 #define DISP_AAL_OUTPUT_SIZE			0x04d8
 #define DISP_AAL_LUT_SIZE			512
 
@@ -56,9 +58,13 @@ void mtk_aal_config(struct device *dev, unsigned int w,
 			   unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
 {
 	struct mtk_disp_aal *aal = dev_get_drvdata(dev);
+	u32 sz;
 
-	mtk_ddp_write(cmdq_pkt, w << 16 | h, &aal->cmdq_reg, aal->regs, DISP_AAL_SIZE);
-	mtk_ddp_write(cmdq_pkt, w << 16 | h, &aal->cmdq_reg, aal->regs, DISP_AAL_OUTPUT_SIZE);
+	sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
+	sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
+
+	mtk_ddp_write(cmdq_pkt, sz, &aal->cmdq_reg, aal->regs, DISP_AAL_SIZE);
+	mtk_ddp_write(cmdq_pkt, sz, &aal->cmdq_reg, aal->regs, DISP_AAL_OUTPUT_SIZE);
 }
 
 /**
-- 
2.41.0

Hi AngeloGioacchino,

kernel test robot noticed the following build errors:

[auto build test ERROR on drm-misc/drm-misc-next]
[also build test ERROR on pza/reset/next]
[cannot apply to pza/imx-drm/next mbgg-mediatek/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/AngeloGioacchino-Del-Regno/drm-mediatek-gamma-Adjust-mtk_drm_gamma_set_common-parameters/20230803-190918
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230803110214.163645-8-angelogioacchino.delregno%40collabora.com
patch subject: [PATCH v9 07/16] drm/mediatek: aal: Use bitfield macros
config: arm-allmodconfig (https://download.01.org/0day-ci/archive/20230804/202308041431.xXkaXQ8u-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230804/202308041431.xXkaXQ8u-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308041431.xXkaXQ8u-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/mediatek/mtk_disp_aal.c: In function 'mtk_aal_config':
>> drivers/gpu/drm/mediatek/mtk_disp_aal.c:63:14: error: implicit declaration of function 'FIELD_PREP' [-Werror=implicit-function-declaration]
      63 |         sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
         |              ^~~~~~~~~~
   drivers/gpu/drm/mediatek/mtk_disp_aal.c:63:25: error: 'DISP_GAMMA_SIZE_HSIZE' undeclared (first use in this function); did you mean 'DISP_AAL_SIZE_HSIZE'?
      63 |         sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
         |                         ^~~~~~~~~~~~~~~~~~~~~
         |                         DISP_AAL_SIZE_HSIZE
   drivers/gpu/drm/mediatek/mtk_disp_aal.c:63:25: note: each undeclared identifier is reported only once for each function it appears in
   drivers/gpu/drm/mediatek/mtk_disp_aal.c:64:26: error: 'DISP_GAMMA_SIZE_VSIZE' undeclared (first use in this function); did you mean 'DISP_AAL_SIZE_VSIZE'?
      64 |         sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
         |                          ^~~~~~~~~~~~~~~~~~~~~
         |                          DISP_AAL_SIZE_VSIZE
   cc1: some warnings being treated as errors


vim +/FIELD_PREP +63 drivers/gpu/drm/mediatek/mtk_disp_aal.c

    55	
    56	void mtk_aal_config(struct device *dev, unsigned int w,
    57				   unsigned int h, unsigned int vrefresh,
    58				   unsigned int bpc, struct cmdq_pkt *cmdq_pkt)
    59	{
    60		struct mtk_disp_aal *aal = dev_get_drvdata(dev);
    61		u32 sz;
    62	
  > 63		sz = FIELD_PREP(DISP_GAMMA_SIZE_HSIZE, w);
    64		sz |= FIELD_PREP(DISP_GAMMA_SIZE_VSIZE, h);
    65	
    66		mtk_ddp_write(cmdq_pkt, sz, &aal->cmdq_reg, aal->regs, DISP_AAL_SIZE);
    67		mtk_ddp_write(cmdq_pkt, sz, &aal->cmdq_reg, aal->regs, DISP_AAL_OUTPUT_SIZE);
    68	}
    69	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki