accel/ivpu/40xx: Ensure clock resource ownership Ack before Power-Up

We need to wait for the CLOCK_RESOURCE_OWN_ACK bit to be set
after configuring the workpoint. This step ensures that the VPU
microcontroller clock is actively toggling and ready for operation.

Previously, we relied solely on the READY bit in the VPU_STATUS
register, which indicated the completion of the workpoint download.
However, this approach was insufficient, as the READY bit could be set
while the device was still running on a sideband clock until the PLL
locked. To guarantee that the PLL is locked and the device is running on
the main clock source, we now wait for the CLOCK_RESOURCE_OWN_ACK before
proceeding with the remainder of the power-up sequence.

Fixes: 79cdc56c4a54 ("accel/ivpu: Add initial support for VPU 4")
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230925121137.872158-4-stanislaw.gruszka@linux.intel.com

diff --git a/drivers/accel/ivpu/ivpu_hw_40xx.c b/drivers/accel/ivpu/ivpu_hw_40xx.c
index 00c5dbb..f4a251a 100644 (file)
--- a/drivers/accel/ivpu/ivpu_hw_40xx.c
+++ b/drivers/accel/ivpu/ivpu_hw_40xx.c
@@ -196,6 +196,14 @@ static int ivpu_pll_wait_for_status_ready(struct ivpu_device *vdev)
        return REGB_POLL_FLD(VPU_40XX_BUTTRESS_VPU_STATUS, READY, 1, PLL_TIMEOUT_US);
 }
 
+static int ivpu_wait_for_clock_own_resource_ack(struct ivpu_device *vdev)
+{
+       if (ivpu_is_simics(vdev))
+               return 0;
+
+       return REGB_POLL_FLD(VPU_40XX_BUTTRESS_VPU_STATUS, CLOCK_RESOURCE_OWN_ACK, 1, TIMEOUT_US);
+}
+
 static void ivpu_pll_init_frequency_ratios(struct ivpu_device *vdev)
 {
        struct ivpu_hw_info *hw = vdev->hw;
@@ -556,6 +564,12 @@ static int ivpu_boot_pwr_domain_enable(struct ivpu_device *vdev)
 {
        int ret;
 
+       ret = ivpu_wait_for_clock_own_resource_ack(vdev);
+       if (ret) {
+               ivpu_err(vdev, "Timed out waiting for clock own resource ACK\n");
+               return ret;
+       }
+
        ivpu_boot_pwr_island_trickle_drive(vdev, true);
        ivpu_boot_pwr_island_drive(vdev, true);
 

diff --git a/drivers/accel/ivpu/ivpu_hw_40xx_reg.h b/drivers/accel/ivpu/ivpu_hw_40xx_reg.h
index 5139cfe..ff4a5d4 100644 (file)
--- a/drivers/accel/ivpu/ivpu_hw_40xx_reg.h
+++ b/drivers/accel/ivpu/ivpu_hw_40xx_reg.h
@@ -70,6 +70,8 @@
 #define VPU_40XX_BUTTRESS_VPU_STATUS_READY_MASK                                BIT_MASK(0)
 #define VPU_40XX_BUTTRESS_VPU_STATUS_IDLE_MASK                         BIT_MASK(1)
 #define VPU_40XX_BUTTRESS_VPU_STATUS_DUP_IDLE_MASK                     BIT_MASK(2)
+#define VPU_40XX_BUTTRESS_VPU_STATUS_CLOCK_RESOURCE_OWN_ACK_MASK       BIT_MASK(6)
+#define VPU_40XX_BUTTRESS_VPU_STATUS_POWER_RESOURCE_OWN_ACK_MASK       BIT_MASK(7)
 #define VPU_40XX_BUTTRESS_VPU_STATUS_PERF_CLK_MASK                     BIT_MASK(11)
 #define VPU_40XX_BUTTRESS_VPU_STATUS_DISABLE_CLK_RELINQUISH_MASK        BIT_MASK(12)