clk: qcom: Add a dummy enable function for GX gdsc (85a3d920) · Commits · 戴 / test

drivers/clk/qcom/gpucc-sdm845.c

+26 −0

Original line number	Diff line number	Diff line
		@@ -131,11 +131,37 @@ static struct gdsc gpu_cx_gdsc = {
		.flags = VOTABLE,
		};

		/*
		* On SDM845 the GPU GX domain is almost entirely controlled by the GMU
		* running in the CX domain so the CPU doesn't need to know anything about the
		* GX domain EXCEPT....
		*
		* Hardware constraints dictate that the GX be powered down before the CX. If
		* the GMU crashes it could leave the GX on. In order to successfully bring back
		* the device the CPU needs to disable the GX headswitch. There being no sane
		* way to reach in and touch that register from deep inside the GPU driver we
		* need to set up the infrastructure to be able to ensure that the GPU can
		* ensure that the GX is off during this super special case. We do this by
		* defining a GX gdsc with a dummy enable function and a "default" disable
		* function.
		*
		* This allows us to attach with genpd_dev_pm_attach_by_name() in the GPU
		* driver. During power up, nothing will happen from the CPU (and the GMU will
		* power up normally but during power down this will ensure that the GX domain
		* is really off - this gives us a semi standard way of doing what we need.
		*/
		static int gx_gdsc_enable(struct generic_pm_domain *domain)
		{
		/* Do nothing but give genpd the impression that we were successful */
		return 0;
		}

		static struct gdsc gpu_gx_gdsc = {
		.gdscr = 0x100c,
		.clamp_io_ctrl = 0x1508,
		.pd = {
		.name = "gpu_gx_gdsc",
		.power_on = gx_gdsc_enable,
		},
		.pwrsts = PWRSTS_OFF_ON,
		.flags = CLAMP_IO \| AON_RESET \| POLL_CFG_GDSCR,