From: Quanyang Wang quanyang.wang@windriver.com
[ Upstream commit 394cdb69a3c30b33524cf1204afe5cceaba69cdc ]
If there is a IOCTL_SET_PLL_FRAC_MODE request sent to ATF ever, we shouldn't skip invoking PM_CLOCK_ENABLE fn even though this pll has been enabled. In ATF implementation, it will only assign the mode to the variable (struct pm_pll *)pll->mode when handling IOCTL_SET_PLL_FRAC_MODE call. Invoking PM_CLOCK_ENABLE can force ATF send request to PWU to set the pll mode to PLL's register.
There is a scenario that happens in enabling VPLL_INT(clk_id:96): 1) VPLL_INT has been enabled during booting. 2) A driver calls clk_set_rate and according to the rate, the VPLL_INT should be set to FRAC mode. Then zynqmp_pll_set_mode is called to pass IOCTL_SET_PLL_FRAC_MODE to ATF. Note that at this point ATF just stores the mode to a variable. 3) This driver calls clk_prepare_enable and zynqmp_pll_enable is called to try to enable VPLL_INT pll. Because of 1), the function zynqmp_pll_enable just returns without doing anything after checking that this pll has been enabled.
In the scenario above, the pll mode of VPLL_INT will never be set successfully. So adding set_pll_mode to check condition to fix it.
Fixes: 3fde0e16d016 ("drivers: clk: Add ZynqMP clock driver") Signed-off-by: Quanyang Wang quanyang.wang@windriver.com Tested-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Link: https://lore.kernel.org/r/20210406153131.601701-1-quanyang.wang@windriver.co... Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/clk/zynqmp/pll.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/zynqmp/pll.c b/drivers/clk/zynqmp/pll.c index 03bfe62c1e62..abe6afbf3407 100644 --- a/drivers/clk/zynqmp/pll.c +++ b/drivers/clk/zynqmp/pll.c @@ -14,10 +14,12 @@ * struct zynqmp_pll - PLL clock * @hw: Handle between common and hardware-specific interfaces * @clk_id: PLL clock ID + * @set_pll_mode: Whether an IOCTL_SET_PLL_FRAC_MODE request be sent to ATF */ struct zynqmp_pll { struct clk_hw hw; u32 clk_id; + bool set_pll_mode; };
#define to_zynqmp_pll(_hw) container_of(_hw, struct zynqmp_pll, hw) @@ -81,6 +83,8 @@ static inline void zynqmp_pll_set_mode(struct clk_hw *hw, bool on) if (ret) pr_warn_once("%s() PLL set frac mode failed for %s, ret = %d\n", __func__, clk_name, ret); + else + clk->set_pll_mode = true; }
/** @@ -240,9 +244,15 @@ static int zynqmp_pll_enable(struct clk_hw *hw) u32 clk_id = clk->clk_id; int ret;
- if (zynqmp_pll_is_enabled(hw)) + /* + * Don't skip enabling clock if there is an IOCTL_SET_PLL_FRAC_MODE request + * that has been sent to ATF. + */ + if (zynqmp_pll_is_enabled(hw) && (!clk->set_pll_mode)) return 0;
+ clk->set_pll_mode = false; + ret = zynqmp_pm_clock_enable(clk_id); if (ret) pr_warn_once("%s() clock enable failed for %s, ret = %d\n",