[PATCH v3 04/15] soc: xilinx: vcu: add helper to wait for PLL locked
Michael Tretter
m.tretter at pengutronix.de
Thu Jan 21 02:16:48 EST 2021
Extract a helper function to wait until the PLL is locked. Also,
disabling the bypass was buried in the exit path on the wait loop.
Separate the different steps and add a helper function to make the code
more readable.
Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
Acked-by: Michal Simek <michal.simek at xilinx.com>
---
Changelog:
v3: none
v2: none
---
drivers/soc/xilinx/xlnx_vcu.c | 46 ++++++++++++++++++++---------------
1 file changed, 27 insertions(+), 19 deletions(-)
diff --git a/drivers/soc/xilinx/xlnx_vcu.c b/drivers/soc/xilinx/xlnx_vcu.c
index 7da9643820a8..0fd8356a3776 100644
--- a/drivers/soc/xilinx/xlnx_vcu.c
+++ b/drivers/soc/xilinx/xlnx_vcu.c
@@ -256,6 +256,22 @@ static void xvcu_write_field_reg(void __iomem *iomem, int offset,
xvcu_write(iomem, offset, val);
}
+static int xvcu_pll_wait_for_lock(struct xvcu_device *xvcu)
+{
+ void __iomem *base = xvcu->vcu_slcr_ba;
+ unsigned long timeout;
+ u32 lock_status;
+
+ timeout = jiffies + msecs_to_jiffies(2000);
+ do {
+ lock_status = xvcu_read(base, VCU_PLL_STATUS);
+ if (lock_status & VCU_PLL_STATUS_LOCK_STATUS_MASK)
+ return 0;
+ } while (!time_after(jiffies, timeout));
+
+ return -ETIMEDOUT;
+}
+
/**
* xvcu_set_vcu_pll_info - Set the VCU PLL info
* @xvcu: Pointer to the xvcu_device structure
@@ -428,8 +444,6 @@ static int xvcu_set_vcu_pll_info(struct xvcu_device *xvcu)
*/
static int xvcu_set_pll(struct xvcu_device *xvcu)
{
- u32 lock_status;
- unsigned long timeout;
int ret;
ret = xvcu_set_vcu_pll_info(xvcu);
@@ -447,24 +461,18 @@ static int xvcu_set_pll(struct xvcu_device *xvcu)
xvcu_write_field_reg(xvcu->vcu_slcr_ba, VCU_PLL_CTRL,
0, VCU_PLL_CTRL_RESET_MASK,
VCU_PLL_CTRL_RESET_SHIFT);
- /*
- * Defined the timeout for the max time to wait the
- * PLL_STATUS to be locked.
- */
- timeout = jiffies + msecs_to_jiffies(2000);
- do {
- lock_status = xvcu_read(xvcu->vcu_slcr_ba, VCU_PLL_STATUS);
- if (lock_status & VCU_PLL_STATUS_LOCK_STATUS_MASK) {
- xvcu_write_field_reg(xvcu->vcu_slcr_ba, VCU_PLL_CTRL,
- 0, VCU_PLL_CTRL_BYPASS_MASK,
- VCU_PLL_CTRL_BYPASS_SHIFT);
- return 0;
- }
- } while (!time_after(jiffies, timeout));
- /* PLL is not locked even after the timeout of the 2sec */
- dev_err(xvcu->dev, "PLL is not locked\n");
- return -ETIMEDOUT;
+ ret = xvcu_pll_wait_for_lock(xvcu);
+ if (ret) {
+ dev_err(xvcu->dev, "PLL is not locked\n");
+ return ret;
+ }
+
+ xvcu_write_field_reg(xvcu->vcu_slcr_ba, VCU_PLL_CTRL,
+ 0, VCU_PLL_CTRL_BYPASS_MASK,
+ VCU_PLL_CTRL_BYPASS_SHIFT);
+
+ return ret;
}
/**
--
2.20.1
More information about the linux-arm-kernel
mailing list