[PATCH 2/5] genpd/gdsc: inherit display powerdomain from bootloader

Rob Clark
2019-06-30T15:02:53Z

From: Rob Clark <robdclark@chromium.org>

Mark power domains that may be enabled by bootloader, and which should
not be disabled until a driver takes them over.

This keeps efifb alive until the real driver can be probed. In a distro
kernel, the driver will most likely built as a module, and not probed
until we get to userspace (after late_initcall)

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/base/power/domain.c | 10 ++++++++++
drivers/clk/qcom/dispcc-sdm845.c | 2 +-
drivers/clk/qcom/gdsc.c | 5 +++++
drivers/clk/qcom/gdsc.h | 1 +
include/linux/pm_domain.h | 4 ++++
5 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 33c30c1e6a30..513a8655fbd7 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -537,6 +537,16 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
not_suspended++;
}

+ /*
+ * If the power domain is enabled by the bootloader (for example
+ * display enabled by bootloader), but no devices attached yet
+ * (perhaps because driver built as kernel module), then do not
+ * suspend.
+ */
+ if ((genpd->flags & GENPD_FLAG_INHERIT_BL) &&
+ list_empty(&genpd->dev_list))
+ not_suspended++;
+
if (not_suspended > 1 || (not_suspended == 1 && !one_dev_on))
return -EBUSY;

diff --git a/drivers/clk/qcom/dispcc-sdm845.c b/drivers/clk/qcom/dispcc-sdm845.c
index 40d7e0ab4340..1d9365ac2315 100644
--- a/drivers/clk/qcom/dispcc-sdm845.c
+++ b/drivers/clk/qcom/dispcc-sdm845.c
@@ -575,7 +575,7 @@ static struct gdsc mdss_gdsc = {
.name = "mdss_gdsc",
},
.pwrsts = PWRSTS_OFF_ON,
- .flags = HW_CTRL | POLL_CFG_GDSCR,
+ .flags = HW_CTRL | POLL_CFG_GDSCR | INHERIT_BL,
};

static struct clk_regmap *disp_cc_sdm845_clocks[] = {
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
index a250f59708d8..4639fbeb9a7f 100644
--- a/drivers/clk/qcom/gdsc.c
+++ b/drivers/clk/qcom/gdsc.c
@@ -331,6 +331,11 @@ static int gdsc_init(struct gdsc *sc)
if ((sc->flags & VOTABLE) && on)
gdsc_enable(&sc->pd);

+ if ((sc->flags & INHERIT_BL) && on) {
+ pr_debug("gdsc: %s is enabled from bootloader!\n", sc->pd.name);
+ sc->pd.flags |= GENPD_FLAG_INHERIT_BL;
+ }
+
/* If ALWAYS_ON GDSCs are not ON, turn them ON */
if (sc->flags & ALWAYS_ON) {
if (!on)
diff --git a/drivers/clk/qcom/gdsc.h b/drivers/clk/qcom/gdsc.h
index 64cdc8cf0d4d..c6fe56247399 100644
--- a/drivers/clk/qcom/gdsc.h
+++ b/drivers/clk/qcom/gdsc.h
@@ -49,6 +49,7 @@ struct gdsc {
#define AON_RESET BIT(4)
#define POLL_CFG_GDSCR BIT(5)
#define ALWAYS_ON BIT(6)
+#define INHERIT_BL BIT(7)
struct reset_controller_dev *rcdev;
unsigned int *resets;
unsigned int reset_count;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 91d9bf497071..5e421afcf6f3 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -55,6 +55,9 @@
*
* GENPD_FLAG_RPM_ALWAYS_ON: Instructs genpd to always keep the PM domain
* powered on except for system suspend.
+ *
+ * GENPD_FLAG_INHERIT_BL: The bootloader has already enabled this power
+ * domain.
*/
#define GENPD_FLAG_PM_CLK (1U << 0)
#define GENPD_FLAG_IRQ_SAFE (1U << 1)
@@ -62,6 +65,7 @@
#define GENPD_FLAG_ACTIVE_WAKEUP (1U << 3)
#define GENPD_FLAG_CPU_DOMAIN (1U << 4)
#define GENPD_FLAG_RPM_ALWAYS_ON (1U << 5)
+#define GENPD_FLAG_INHERIT_BL (1U << 6)

enum gpd_status {
GPD_STATE_ACTIVE = 0, /* PM domain is active */
--
2.20.1