linux/drivers/clk/zynqmp
Quanyang Wang 394cdb69a3 clk: zynqmp: pll: add set_pll_mode to check condition in zynqmp_pll_enable
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: 3fde0e16d0 ("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.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-04-07 18:09:35 -07:00
..
clk-gate-zynqmp.c firmware: xilinx: Remove eemi ops for clock_getstate 2020-04-28 15:45:07 +02:00
clk-mux-zynqmp.c firmware: xilinx: Remove eemi ops for clock set/get parent 2020-04-28 15:45:08 +02:00
clk-zynqmp.h clk: zynqmp: Add support for custom type flags 2020-05-26 17:59:10 -07:00
clkc.c This time around we have 4 lines of diff in the core framework, removing a 2020-06-10 11:42:19 -07:00
divider.c clk: zynqmp: divider: Add missing description for 'max_div' 2021-02-11 11:56:06 -08:00
Kconfig clk: zynqmp: Drop dependency on ARCH_ZYNQMP 2021-04-07 17:26:09 -07:00
Makefile
pll.c clk: zynqmp: pll: add set_pll_mode to check condition in zynqmp_pll_enable 2021-04-07 18:09:35 -07:00