Power Management support for CAAM

Platform can go in sleep where CAAM will remain power ON while in some
cases CAAM will be powered off during deep-sleep. The patch handles
graceful recovery of CAAM state in both the power-up and powered-down
cases across deep-sleep.

Signed-off-by: Yashpal Dutta <yashpal.dutta@freescale.com>
Change-Id: Ie27fdfa78fc50c9a05f6316938ad42a70a89a48e
Reviewed-on: http://git.am.freescale.net:8181/9771
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Reviewed-by: Jose Rivera <German.Rivera@freescale.com>
Reviewed-on: http://git.am.freescale.net:8181/10085

1 files changed, 164 insertions, 62 deletions

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index ef249a5..712a4c3 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -312,13 +312,12 @@ static int caam_remove(struct platform_device *pdev)
 /*
  * kick_trng - sets the various parameters for enabling the initialization
  *	       of the RNG4 block in CAAM
- * @pdev - pointer to the platform device
+ * @pdev - pointer to the caam device
  * @ent_delay - Defines the length (in system clocks) of each entropy sample.
  */
-static void kick_trng(struct platform_device *pdev, int ent_delay)
+static void kick_trng(struct device *dev, int ent_delay)
 {
-	struct device *ctrldev = &pdev->dev;
-	struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
 	struct caam_full __iomem *topregs;
 	struct rng4tst __iomem *r4tst;
 	u32 val;
@@ -375,10 +374,77 @@ int caam_get_era(void)
 }
 EXPORT_SYMBOL(caam_get_era);
 
+static int caam_rng_init(struct device *dev)
+{
+	int gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN;
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
+	u64 cha_vid;
+	struct caam_full __iomem *topregs;
+	int ret = 0;
+
+	topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
+	cha_vid = rd_reg64(&topregs->ctrl.perfmon.cha_id);
+	/*
+	 * If SEC has RNG version >= 4 and RNG state handle has not been
+	 * already instantiated, do RNG instantiation
+	 */
+	if ((cha_vid & CHA_ID_RNG_MASK) >> CHA_ID_RNG_SHIFT >= 4) {
+		ctrlpriv->rng4_sh_init =
+			rd_reg32(&topregs->ctrl.r4tst[0].rdsta);
+		/*
+		 * If the secure keys (TDKEK, JDKEK, TDSK), were already
+		 * generated, signal this to the function that is instantiating
+		 * the state handles. An error would occur if RNG4 attempts
+		 * to regenerate these keys before the next POR.
+		 */
+		gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1;
+		ctrlpriv->rng4_sh_init &= RDSTA_IFMASK;
+		do {
+			int inst_handles =
+				rd_reg32(&topregs->ctrl.r4tst[0].rdsta) &
+								RDSTA_IFMASK;
+			/*
+			 * If either SH were instantiated by somebody else
+			 * (e.g. u-boot) then it is assumed that the entropy
+			 * parameters are properly set and thus the function
+			 * setting these (kick_trng(...)) is skipped.
+			 * Also, if a handle was instantiated, do not change
+			 * the TRNG parameters.
+			 */
+			if (!(ctrlpriv->rng4_sh_init || inst_handles)) {
+				kick_trng(dev, ent_delay);
+				ent_delay += 400;
+			}
+			/*
+			 * if instantiate_rng(...) fails, the loop will rerun
+			 * and the kick_trng(...) function will modfiy the
+			 * upper and lower limits of the entropy sampling
+			 * interval, leading to a sucessful initialization of
+			 * the RNG.
+			 */
+			ret = instantiate_rng(dev, inst_handles,
+					      gen_sk);
+		} while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
+		if (ret) {
+			dev_err(dev, "failed to instantiate RNG");
+			return ret;
+		}
+		/*
+		 * Set handles init'ed by this module as the complement of the
+		 * already initialized ones
+		 */
+		ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_IFMASK;
+
+		/* Enable RDB bit so that RNG works faster */
+		setbits32(&topregs->ctrl.scfgr, SCFGR_RDBENABLE);
+	}
+	return 0;
+}
+
 /* Probe routine for CAAM top (controller) level */
 static int caam_probe(struct platform_device *pdev)
 {
-	int ret, ring, rspec, gen_sk, ent_delay = RTSDCTL_ENT_DLY_MIN;
+	int ret, ring, rspec;
 	u64 caam_id;
 	struct device *dev;
 	struct device_node *nprop, *np;
@@ -388,7 +454,6 @@ static int caam_probe(struct platform_device *pdev)
 #ifdef CONFIG_DEBUG_FS
 	struct caam_perfmon *perfmon;
 #endif
-	u64 cha_vid;
 
 	ctrlpriv = kzalloc(sizeof(struct caam_drv_private), GFP_KERNEL);
 	if (!ctrlpriv)
@@ -498,62 +563,10 @@ static int caam_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
-	cha_vid = rd_reg64(&topregs->ctrl.perfmon.cha_id);
-
-	/*
-	 * If SEC has RNG version >= 4 and RNG state handle has not been
-	 * already instantiated, do RNG instantiation
-	 */
-	if ((cha_vid & CHA_ID_RNG_MASK) >> CHA_ID_RNG_SHIFT >= 4) {
-		ctrlpriv->rng4_sh_init =
-			rd_reg32(&topregs->ctrl.r4tst[0].rdsta);
-		/*
-		 * If the secure keys (TDKEK, JDKEK, TDSK), were already
-		 * generated, signal this to the function that is instantiating
-		 * the state handles. An error would occur if RNG4 attempts
-		 * to regenerate these keys before the next POR.
-		 */
-		gen_sk = ctrlpriv->rng4_sh_init & RDSTA_SKVN ? 0 : 1;
-		ctrlpriv->rng4_sh_init &= RDSTA_IFMASK;
-		do {
-			int inst_handles =
-				rd_reg32(&topregs->ctrl.r4tst[0].rdsta) &
-								RDSTA_IFMASK;
-			/*
-			 * If either SH were instantiated by somebody else
-			 * (e.g. u-boot) then it is assumed that the entropy
-			 * parameters are properly set and thus the function
-			 * setting these (kick_trng(...)) is skipped.
-			 * Also, if a handle was instantiated, do not change
-			 * the TRNG parameters.
-			 */
-			if (!(ctrlpriv->rng4_sh_init || inst_handles)) {
-				kick_trng(pdev, ent_delay);
-				ent_delay += 400;
-			}
-			/*
-			 * if instantiate_rng(...) fails, the loop will rerun
-			 * and the kick_trng(...) function will modfiy the
-			 * upper and lower limits of the entropy sampling
-			 * interval, leading to a sucessful initialization of
-			 * the RNG.
-			 */
-			ret = instantiate_rng(dev, inst_handles,
-					      gen_sk);
-		} while ((ret == -EAGAIN) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
-		if (ret) {
-			dev_err(dev, "failed to instantiate RNG");
-			caam_remove(pdev);
-			return ret;
-		}
-		/*
-		 * Set handles init'ed by this module as the complement of the
-		 * already initialized ones
-		 */
-		ctrlpriv->rng4_sh_init = ~ctrlpriv->rng4_sh_init & RDSTA_IFMASK;
-
-		/* Enable RDB bit so that RNG works faster */
-		setbits32(&topregs->ctrl.scfgr, SCFGR_RDBENABLE);
+	ret = caam_rng_init(dev);
+	if (ret) {
+		caam_remove(pdev);
+		return ret;
 	}
 
 	/* NOTE: RTIC detection ought to go here, around Si time */
@@ -649,6 +662,92 @@ static int caam_probe(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int caam_stop_qi(struct caam_full __iomem *topregs)
+{
+	int qi_stopped, loop = 0;
+
+	setbits32(&topregs->qi.qi_control_lo, QICTL_STOP);
+
+	/*
+	 * Wait till QI Job's in Holding tank/deco are completed.
+	 * No dequeue from QI will be happen till QI interface is
+	 * reenabled.
+	 */
+	while (loop <= 100000) {
+		qi_stopped = rd_reg32(&topregs->qi.qi_status) &
+			 QISTA_STOPD;
+		if (qi_stopped) {
+			wr_reg32(&topregs->qi.qi_control_lo,
+				 QICTL_STOP);
+			return 0;
+		}
+		loop++;
+	}
+
+	/* Failed to stop QI interface. Reenable QI Interface */
+	wr_reg32(&topregs->qi.qi_control_lo, QICTL_DQEN);
+	return -EBUSY;
+}
+
+/* Suspend handler for caam device */
+static int caam_suspend(struct device *dev)
+{
+	struct caam_drv_private *caam_priv;
+	struct caam_full __iomem *topregs;
+	struct caam_ctrl __iomem *ctrl;
+	int ret = 0;
+
+	caam_priv = dev_get_drvdata(dev);
+	ctrl = caam_priv->ctrl;
+	topregs = (struct caam_full __iomem *)ctrl;
+
+	/* QI Interface graceful stoppping during suspend */
+	if (caam_priv->qi_present) {
+		int qi_dqen;
+
+		qi_dqen = rd_reg32(&topregs->qi.qi_control_lo) &
+			QICTL_DQEN;
+		if (qi_dqen)
+			ret = caam_stop_qi(topregs);
+	}
+
+	return ret;
+}
+
+/* Resume handler for caam device */
+static int caam_resume(struct device *dev)
+{
+	struct caam_drv_private *caam_priv;
+	struct caam_full __iomem *topregs;
+	struct caam_ctrl __iomem *ctrl;
+	int ret;
+
+	caam_priv = dev_get_drvdata(dev);
+	ctrl = caam_priv->ctrl;
+	topregs = (struct caam_full __iomem *)ctrl;
+	/*
+	 * Enable DECO watchdogs and, if this is a PHYS_ADDR_T_64BIT kernel,
+	 * long pointers in master configuration register
+	 */
+	setbits32(&topregs->ctrl.mcr, MCFGR_WDENABLE |
+		  (sizeof(dma_addr_t) == sizeof(u64) ? MCFGR_LONG_PTR : 0));
+
+	/* Enable QI interface of SEC */
+	if (caam_priv->qi_present)
+		wr_reg32(&topregs->qi.qi_control_lo, QICTL_DQEN);
+
+	ret = caam_rng_init(dev);
+
+	return ret;
+}
+
+const struct dev_pm_ops caam_pm_ops = {
+	.suspend = caam_suspend,
+	.resume = caam_resume,
+};
+#endif /* CONFIG_PM */
+
 static struct of_device_id caam_match[] = {
 	{
 		.compatible = "fsl,sec-v4.0",
@@ -665,6 +764,9 @@ static struct platform_driver caam_driver = {
 		.name = "caam",
 		.owner = THIS_MODULE,
 		.of_match_table = caam_match,
+#ifdef CONFIG_PM
+		.pm = &caam_pm_ops,
+#endif
 	},
 	.probe       = caam_probe,
 	.remove      = caam_remove,