[PATCHv5 6/9] OMAP: Powerdomains: Add support for checking if pwrdm/clkdm can idle

[Tero Kristo <tero.kristo@nokia.com>]

From: Tero Kristo <tero.kristo@nokia.com>

pwrdm_can_idle(pwrdm) will check if the specified powerdomain can enter
idle. This is done by checking all clockdomains under the powerdomain
if they can idle also.

omap2_clkdm_can_idle(clkdm) will check if the specified clockdomain can
enter idle. This checks the functional clocks and idle status bits of the
domain according to following rules:
1) functional clock check
  * get FCLK register content
  * ignore all clocks defined in idle_def.fclk_ignore
  * if any active functional clocks remain, domain can't idle
2) idle status check
  * get IDLEST register content
  * inverse it (any non-idle blocks are now as 1)
  * mask against idle_def.idlest_mask
  * if any bits remain high, domain can't idle

These calls can be used e.g. inside cpuidle to decide which power states
core and mpu should enter during idle, as there are certain dependencies
between wakeup capabilities and reset logic.

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
---
 arch/arm/mach-omap2/clockdomain.c             |   32 ++++++++
 arch/arm/mach-omap2/clockdomains.h            |  106 +++++++++++++++++++++++++
 arch/arm/mach-omap2/powerdomain.c             |   25 ++++++
 arch/arm/plat-omap/include/plat/clockdomain.h |   17 ++++
 arch/arm/plat-omap/include/plat/powerdomain.h |    1 +
 5 files changed, 181 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index dd285f0..63020d4 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -472,6 +472,38 @@ int omap2_clkdm_wakeup(struct clockdomain *clkdm)
 	return 0;
 }
 
+
+/**
+ * omap2_clkdm_can_idle - check if clockdomain has any active clocks or not
+ * @clkdm: struct clockdomain *
+ *
+ * Checks if the clockdomain has any active clock or not, i.e. whether it
+ * can enter idle. Returns -EINVAL if clkdm is NULL; 0 if unable to idle;
+ * 1 if can idle.
+ */
+int omap2_clkdm_can_idle(struct clockdomain *clkdm)
+{
+	int i;
+
+	if (!clkdm)
+		return -EINVAL;
+
+	for (i = 0; i < clkdm->clk_reg_num; i++) {
+		u32 idlest, fclk;
+
+		fclk = cm_read_mod_reg(clkdm->pwrdm.ptr->prcm_offs,
+				CM_FCLKEN + 4 * i);
+		if (fclk & ~clkdm->idle_def[i].fclk_ignore)
+			return 0;
+
+		idlest = cm_read_mod_reg(clkdm->pwrdm.ptr->prcm_offs,
+				CM_IDLEST + 4 * i);
+		if (~idlest & clkdm->idle_def[i].idlest_mask)
+			return 0;
+	}
+	return 1;
+}
+
 /**
  * omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
  * @clkdm: struct clockdomain *
diff --git a/arch/arm/mach-omap2/clockdomains.h b/arch/arm/mach-omap2/clockdomains.h
index c4ee076..65e2f69 100644
--- a/arch/arm/mach-omap2/clockdomains.h
+++ b/arch/arm/mach-omap2/clockdomains.h
@@ -167,6 +167,12 @@ static struct clockdomain iva2_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430_CLKTRCTRL_IVA2_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.idlest_mask = OMAP3430_ST_IVA2,
+		},
+	},
 };
 
 static struct clockdomain gfx_3430es1_clkdm = {
@@ -183,6 +189,12 @@ static struct clockdomain sgx_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430ES2_CLKTRCTRL_SGX_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_GE_OMAP3430ES2),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.idlest_mask = OMAP3430ES2_ST_SGX_SHIFT,
+		},
+	},
 };
 
 /*
@@ -206,6 +218,57 @@ static struct clockdomain core_l3_34xx_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP,
 	.clktrctrl_mask = OMAP3430_CLKTRCTRL_L3_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
+	.clk_reg_num	= 3,
+	.idle_def	= {
+		[0] = {
+			/* UARTs are controlled by idle loop so ignore */
+			.fclk_ignore = OMAP3430_EN_UART2 |
+				OMAP3430_EN_UART1,
+			/*
+			 * Reason for IDLEST ignores:
+			 * - SDRC and OMAPCTRL controlled by HW
+			 * - HSOTGUSB_IDLE bit is autoidled by HW
+			 * - MAILBOX is controlled by HW
+			 */
+			.idlest_mask =
+				OMAP3430ES2_ST_MMC3_MASK |
+				OMAP3430_ST_ICR_MASK |
+				OMAP3430_ST_AES2_MASK |
+				OMAP3430_ST_SHA12_MASK |
+				OMAP3430_ST_DES2_MASK |
+				OMAP3430_ST_MMC2_MASK |
+				OMAP3430_ST_MMC1_MASK |
+				OMAP3430_ST_MSPRO_MASK |
+				OMAP3430_ST_HDQ_MASK |
+				OMAP3430_ST_MCSPI4_MASK |
+				OMAP3430_ST_MCSPI3_MASK |
+				OMAP3430_ST_MCSPI2_MASK |
+				OMAP3430_ST_MCSPI1_MASK |
+				OMAP3430_ST_I2C3_MASK |
+				OMAP3430_ST_I2C2_MASK |
+				OMAP3430_ST_I2C1_MASK |
+				OMAP3430_ST_GPT11_MASK |
+				OMAP3430_ST_GPT10_MASK |
+				OMAP3430_ST_MCBSP5_MASK |
+				OMAP3430_ST_MCBSP1_MASK |
+				OMAP3430ES2_ST_SSI_IDLE_MASK |
+				OMAP3430ES2_ST_HSOTGUSB_STDBY_MASK |
+				OMAP3430_ST_D2D_MASK |
+				OMAP3430_ST_SDMA_MASK |
+				OMAP3430_ST_SSI_STDBY_MASK,
+		},
+		[1] = {
+			.idlest_mask = OMAP3430_ST_PKA_MASK |
+				OMAP3430_ST_AES1_MASK |
+				OMAP3430_ST_RNG_MASK |
+				OMAP3430_ST_SHA11_MASK |
+				OMAP3430_ST_DES1_MASK,
+		},
+		[2] = {
+			.idlest_mask = OMAP3430ES2_ST_USBTLL_MASK |
+				OMAP3430ES2_ST_CPEFUSE_MASK,
+		},
+	},
 };
 
 static struct clockdomain core_l4_34xx_clkdm = {
@@ -222,6 +285,13 @@ static struct clockdomain dss_34xx_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430_CLKTRCTRL_DSS_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.idlest_mask = OMAP3430ES2_ST_DSS_IDLE_MASK |
+				OMAP3430ES2_ST_DSS_STDBY_MASK,
+		},
+	},
 };
 
 static struct clockdomain cam_clkdm = {
@@ -230,6 +300,12 @@ static struct clockdomain cam_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430_CLKTRCTRL_CAM_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.idlest_mask = OMAP3430_ST_CAM,
+		},
+	},
 };
 
 static struct clockdomain usbhost_clkdm = {
@@ -238,6 +314,13 @@ static struct clockdomain usbhost_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430ES2_CLKTRCTRL_USBHOST_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_GE_OMAP3430ES2),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.idlest_mask = OMAP3430ES2_ST_USBHOST_IDLE_MASK |
+				OMAP3430ES2_ST_USBHOST_STDBY_MASK,
+		},
+	},
 };
 
 static struct clockdomain per_clkdm = {
@@ -246,6 +329,29 @@ static struct clockdomain per_clkdm = {
 	.flags		= CLKDM_CAN_HWSUP_SWSUP,
 	.clktrctrl_mask = OMAP3430_CLKTRCTRL_PER_MASK,
 	.omap_chip	= OMAP_CHIP_INIT(CHIP_IS_OMAP3430),
+	.clk_reg_num	= 1,
+	.idle_def	= {
+		[0] = {
+			.fclk_ignore = OMAP3430_ST_UART3_MASK,
+			/*
+			 * GPIO2...6 are dropped out from this mask
+			 * as they are always non-idle, UART3 is also
+			 * out as it is handled by idle loop
+			 * */
+			.idlest_mask = OMAP3430_ST_WDT3_MASK |
+				OMAP3430_ST_GPT9_MASK |
+				OMAP3430_ST_GPT8_MASK |
+				OMAP3430_ST_GPT7_MASK |
+				OMAP3430_ST_GPT6_MASK |
+				OMAP3430_ST_GPT5_MASK |
+				OMAP3430_ST_GPT4_MASK |
+				OMAP3430_ST_GPT3_MASK |
+				OMAP3430_ST_GPT2_MASK |
+				OMAP3430_ST_MCBSP4_MASK |
+				OMAP3430_ST_MCBSP3_MASK |
+				OMAP3430_ST_MCBSP2_MASK,
+		},
+	},
 };
 
 /*
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index 26b3f3e..cdbe7a9 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -1199,6 +1199,31 @@ int pwrdm_wait_transition(struct powerdomain *pwrdm)
 	return 0;
 }
 
+/**
+ * pwrdm_can_idle - check if the powerdomain can enter idle
+ * @pwrdm: struct powerdomain * the powerdomain to check status of
+ *
+ * Checks all associated clockdomains if they can idle or not.
+ * Returns 1 if the powerdomain can idle, 0 if not.
+ */
+int pwrdm_can_idle(struct powerdomain *pwrdm)
+{
+	unsigned long flags;
+	int i;
+	int ret = 1;
+
+	read_lock_irqsave(&pwrdm_rwlock, flags);
+
+	for (i = 0; i < PWRDM_MAX_CLKDMS; i++)
+		if (pwrdm->pwrdm_clkdms[i] &&
+		    !omap2_clkdm_can_idle(pwrdm->pwrdm_clkdms[i]))
+			ret = 0;
+
+	read_unlock_irqrestore(&pwrdm_rwlock, flags);
+
+	return ret;
+}
+
 int pwrdm_state_switch(struct powerdomain *pwrdm)
 {
 	return _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
diff --git a/arch/arm/plat-omap/include/plat/clockdomain.h b/arch/arm/plat-omap/include/plat/clockdomain.h
index eb73482..4ccb8c0 100644
--- a/arch/arm/plat-omap/include/plat/clockdomain.h
+++ b/arch/arm/plat-omap/include/plat/clockdomain.h
@@ -30,6 +30,12 @@
 #define CLKDM_CAN_SWSUP		(CLKDM_CAN_FORCE_SLEEP | CLKDM_CAN_FORCE_WAKEUP)
 #define CLKDM_CAN_HWSUP_SWSUP	(CLKDM_CAN_SWSUP | CLKDM_CAN_HWSUP)
 
+/*
+ * Maximum number of FCLK register masks that can be associated with a
+ * clockdomain. CORE powerdomain on OMAP3 is the worst case
+ */
+#define CLKDM_MAX_CLK_REGS			3
+
 /* OMAP24XX CM_CLKSTCTRL_*.AUTOSTATE_* register bit values */
 #define OMAP24XX_CLKSTCTRL_DISABLE_AUTO		0x0
 #define OMAP24XX_CLKSTCTRL_ENABLE_AUTO		0x1
@@ -61,6 +67,11 @@ struct clkdm_pwrdm_autodep {
 
 };
 
+struct clkdm_idle_def {
+	u32 fclk_ignore;
+	u32 idlest_mask;
+};
+
 struct clockdomain {
 
 	/* Clockdomain name */
@@ -83,6 +94,10 @@ struct clockdomain {
 	/* OMAP chip types that this clockdomain is valid on */
 	const struct omap_chip_id omap_chip;
 
+	/* For idle checks */
+	u8 clk_reg_num;
+	struct clkdm_idle_def idle_def[CLKDM_MAX_CLK_REGS];
+
 	/* Usecount tracking */
 	atomic_t usecount;
 
@@ -108,4 +123,6 @@ int omap2_clkdm_sleep(struct clockdomain *clkdm);
 int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk);
 int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk);
 
+int omap2_clkdm_can_idle(struct clockdomain *clkdm);
+
 #endif
diff --git a/arch/arm/plat-omap/include/plat/powerdomain.h b/arch/arm/plat-omap/include/plat/powerdomain.h
index 0b96005..ebac4e1 100644
--- a/arch/arm/plat-omap/include/plat/powerdomain.h
+++ b/arch/arm/plat-omap/include/plat/powerdomain.h
@@ -178,6 +178,7 @@ int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm);
 bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm);
 
 int pwrdm_wait_transition(struct powerdomain *pwrdm);
+int pwrdm_can_idle(struct powerdomain *pwrdm);
 
 int pwrdm_state_switch(struct powerdomain *pwrdm);
 int pwrdm_clkdm_state_switch(struct clockdomain *clkdm);
-- 
1.5.4.3