Re: [PATCH v2 2/8] drm/msm/a6xx: use AOP-initialized PDC for a650

From: Akhil P Oommen
Date: Mon May 31 2021 - 03:24:37 EST


On 5/13/2021 10:43 PM, Jonathan Marek wrote:
SM8250 AOP firmware already sets up PDC registers for us, and it only needs
to be enabled. This path will be used for other newer GPUs.

Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 21 ++++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 3d55e153fa9c..c1ee02d6371d 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -512,19 +512,26 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
struct platform_device *pdev = to_platform_device(gmu->dev);
void __iomem *pdcptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc");
- void __iomem *seqptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc_seq");
+ void __iomem *seqptr;
uint32_t pdc_address_offset;
+ bool pdc_in_aop = false;
- if (!pdcptr || !seqptr)
+ if (!pdcptr)
goto err;
- if (adreno_is_a618(adreno_gpu) || adreno_is_a640(adreno_gpu))
+ if (adreno_is_a650(adreno_gpu))
+ pdc_in_aop = true;
+ else if (adreno_is_a618(adreno_gpu) || adreno_is_a640(adreno_gpu))
pdc_address_offset = 0x30090;
- else if (adreno_is_a650(adreno_gpu))
- pdc_address_offset = 0x300a0;
else
pdc_address_offset = 0x30080;
+ if (!pdc_in_aop) {
+ seqptr = a6xx_gmu_get_mmio(pdev, "gmu_pdc_seq");
+ if (!seqptr)
+ goto err;
+ }
+
/* Disable SDE clock gating */
gmu_write_rscc(gmu, REG_A6XX_GPU_RSCC_RSC_STATUS0_DRV0, BIT(24));
@@ -556,6 +563,9 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
gmu_write_rscc(gmu, REG_A6XX_RSCC_SEQ_MEM_0_DRV0 + 4, 0x0020e8a8);
}
+ if (pdc_in_aop)
+ goto setup_pdc;
+
/* Load PDC sequencer uCode for power up and power down sequence */
pdc_write(seqptr, REG_A6XX_PDC_GPU_SEQ_MEM_0, 0xfebea1e1);
pdc_write(seqptr, REG_A6XX_PDC_GPU_SEQ_MEM_0 + 1, 0xa5a4a3a2);
@@ -596,6 +606,7 @@ static void a6xx_gmu_rpmh_init(struct a6xx_gmu *gmu)
pdc_write(pdcptr, REG_A6XX_PDC_GPU_TCS3_CMD0_DATA + 8, 0x3);
/* Setup GPU PDC */
+setup_pdc:
pdc_write(pdcptr, REG_A6XX_PDC_GPU_SEQ_START_ADDR, 0);
pdc_write(pdcptr, REG_A6XX_PDC_GPU_ENABLE_PDC, 0x80000001);


We can simply swap the order of PDC and rsc programming here and skip pdc sequence to jump to the rscc programming for a650. This is the order followed in the downstream driver anyway.

-Akhil.