clk: qcom: Handle the clamp_io assert/deassert sequence

Add a flag to mark gdscs which need to support the clamp deassert/assert
before and after the gdsc enable/disable

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/qcom/gdsc.c

@@ -30,6 +30,7 @@
 #define SW_OVERRIDE_MASK	BIT(2)
 #define HW_CONTROL_MASK		BIT(1)
 #define SW_COLLAPSE_MASK	BIT(0)
+#define GMEM_CLAMP_IO_MASK	BIT(0)
 
 /* Wait 2^n CXO cycles between all states. Here, n=2 (4 cycles). */
 #define EN_REST_WAIT_VAL	(0x2 << 20)
@@ -140,6 +141,18 @@ static inline void gdsc_clear_mem_on(struct gdsc *sc)
 		regmap_update_bits(sc->regmap, sc->cxcs[i], mask, 0);
 }
 
+static inline void gdsc_deassert_clamp_io(struct gdsc *sc)
+{
+	regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+			   GMEM_CLAMP_IO_MASK, 0);
+}
+
+static inline void gdsc_assert_clamp_io(struct gdsc *sc)
+{
+	regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+			   GMEM_CLAMP_IO_MASK, 1);
+}
+
 static int gdsc_enable(struct generic_pm_domain *domain)
 {
 	struct gdsc *sc = domain_to_gdsc(domain);
@@ -148,6 +161,9 @@ static int gdsc_enable(struct generic_pm_domain *domain)
 	if (sc->pwrsts == PWRSTS_ON)
 		return gdsc_deassert_reset(sc);
 
+	if (sc->flags & CLAMP_IO)
+		gdsc_deassert_clamp_io(sc);
+
 	ret = gdsc_toggle_logic(sc, true);
 	if (ret)
 		return ret;
@@ -170,6 +186,7 @@ static int gdsc_enable(struct generic_pm_domain *domain)
 static int gdsc_disable(struct generic_pm_domain *domain)
 {
 	struct gdsc *sc = domain_to_gdsc(domain);
+	int ret;
 
 	if (sc->pwrsts == PWRSTS_ON)
 		return gdsc_assert_reset(sc);
@@ -177,7 +194,14 @@ static int gdsc_disable(struct generic_pm_domain *domain)
 	if (sc->pwrsts & PWRSTS_OFF)
 		gdsc_clear_mem_on(sc);
 
-	return gdsc_toggle_logic(sc, false);
+	ret = gdsc_toggle_logic(sc, false);
+	if (ret)
+		return ret;
+
+	if (sc->flags & CLAMP_IO)
+		gdsc_assert_clamp_io(sc);
+
+	return 0;
 }
 
 static int gdsc_init(struct gdsc *sc)

drivers/clk/qcom/gdsc.h

@@ -39,6 +39,7 @@ struct gdsc {
 	struct regmap			*regmap;
 	unsigned int			gdscr;
 	unsigned int			gds_hw_ctrl;
+	unsigned int			clamp_io_ctrl;
 	unsigned int			*cxcs;
 	unsigned int			cxc_count;
 	const u8			pwrsts;
@@ -50,6 +51,7 @@ struct gdsc {
 #define PWRSTS_RET_ON		(PWRSTS_RET | PWRSTS_ON)
 	const u8			flags;
 #define VOTABLE		BIT(0)
+#define CLAMP_IO	BIT(1)
 	struct reset_controller_dev	*rcdev;
 	unsigned int			*resets;
 	unsigned int			reset_count;