crypto: caam - add power management support

Add support for suspend and resume operation for PM in CAAM driver.

When the CAAM goes in suspend, the hardware is considered to do nothing.

On some platforms, the power of the CAAM is not turned off so it keeps
its configuration.
On other platforms, it doesn't so it is necessary to save the state of
the CAAM:
 - JRs MID
 - Address of input and output rings

Signed-off-by: Horia Geanta <horia.geanta@nxp.com>
Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com>
Signed-off-by: Dan Douglass <dan.douglass@nxp.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: Franck LENORMAND <franck.lenormand@nxp.com>
Signed-off-by: Meenakshi Aggarwal <meenakshi.aggarwal@nxp.com>
Reviewed-by: Gaurav Jain <gaurav.jain@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 106 insertions, 0 deletions

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index ff9ddbbca377..a7a4583107f4 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -740,6 +740,109 @@ static int caam_ctrl_rng_init(struct device *dev)
 	return 0;
 }
 
+/* Indicate if the internal state of the CAAM is lost during PM */
+static int caam_off_during_pm(void)
+{
+	bool not_off_during_pm = of_machine_is_compatible("fsl,imx6q") ||
+				 of_machine_is_compatible("fsl,imx6qp") ||
+				 of_machine_is_compatible("fsl,imx6dl");
+
+	return not_off_during_pm ? 0 : 1;
+}
+
+static void caam_state_save(struct device *dev)
+{
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
+	struct caam_ctl_state *state = &ctrlpriv->state;
+	struct caam_ctrl __iomem *ctrl = ctrlpriv->ctrl;
+	u32 deco_inst, jr_inst;
+	int i;
+
+	state->mcr = rd_reg32(&ctrl->mcr);
+	state->scfgr = rd_reg32(&ctrl->scfgr);
+
+	deco_inst = (rd_reg32(&ctrl->perfmon.cha_num_ms) &
+		     CHA_ID_MS_DECO_MASK) >> CHA_ID_MS_DECO_SHIFT;
+	for (i = 0; i < deco_inst; i++) {
+		state->deco_mid[i].liodn_ms =
+			rd_reg32(&ctrl->deco_mid[i].liodn_ms);
+		state->deco_mid[i].liodn_ls =
+			rd_reg32(&ctrl->deco_mid[i].liodn_ls);
+	}
+
+	jr_inst = (rd_reg32(&ctrl->perfmon.cha_num_ms) &
+		   CHA_ID_MS_JR_MASK) >> CHA_ID_MS_JR_SHIFT;
+	for (i = 0; i < jr_inst; i++) {
+		state->jr_mid[i].liodn_ms =
+			rd_reg32(&ctrl->jr_mid[i].liodn_ms);
+		state->jr_mid[i].liodn_ls =
+			rd_reg32(&ctrl->jr_mid[i].liodn_ls);
+	}
+}
+
+static void caam_state_restore(const struct device *dev)
+{
+	const struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
+	const struct caam_ctl_state *state = &ctrlpriv->state;
+	struct caam_ctrl __iomem *ctrl = ctrlpriv->ctrl;
+	u32 deco_inst, jr_inst;
+	int i;
+
+	wr_reg32(&ctrl->mcr, state->mcr);
+	wr_reg32(&ctrl->scfgr, state->scfgr);
+
+	deco_inst = (rd_reg32(&ctrl->perfmon.cha_num_ms) &
+		     CHA_ID_MS_DECO_MASK) >> CHA_ID_MS_DECO_SHIFT;
+	for (i = 0; i < deco_inst; i++) {
+		wr_reg32(&ctrl->deco_mid[i].liodn_ms,
+			 state->deco_mid[i].liodn_ms);
+		wr_reg32(&ctrl->deco_mid[i].liodn_ls,
+			 state->deco_mid[i].liodn_ls);
+	}
+
+	jr_inst = (rd_reg32(&ctrl->perfmon.cha_num_ms) &
+		   CHA_ID_MS_JR_MASK) >> CHA_ID_MS_JR_SHIFT;
+	for (i = 0; i < jr_inst; i++) {
+		wr_reg32(&ctrl->jr_mid[i].liodn_ms,
+			 state->jr_mid[i].liodn_ms);
+		wr_reg32(&ctrl->jr_mid[i].liodn_ls,
+			 state->jr_mid[i].liodn_ls);
+	}
+
+	if (ctrlpriv->virt_en == 1)
+		clrsetbits_32(&ctrl->jrstart, 0, JRSTART_JR0_START |
+			      JRSTART_JR1_START | JRSTART_JR2_START |
+			      JRSTART_JR3_START);
+}
+
+static int caam_ctrl_suspend(struct device *dev)
+{
+	const struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
+
+	if (ctrlpriv->caam_off_during_pm && !ctrlpriv->optee_en)
+		caam_state_save(dev);
+
+	return 0;
+}
+
+static int caam_ctrl_resume(struct device *dev)
+{
+	struct caam_drv_private *ctrlpriv = dev_get_drvdata(dev);
+	int ret = 0;
+
+	if (ctrlpriv->caam_off_during_pm && !ctrlpriv->optee_en) {
+		caam_state_restore(dev);
+
+		/* HW and rng will be reset so deinstantiation can be removed */
+		devm_remove_action(dev, devm_deinstantiate_rng, dev);
+		ret = caam_ctrl_rng_init(dev);
+	}
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(caam_ctrl_pm_ops, caam_ctrl_suspend, caam_ctrl_resume);
+
 /* Probe routine for CAAM top (controller) level */
 static int caam_probe(struct platform_device *pdev)
 {
@@ -771,6 +874,8 @@ static int caam_probe(struct platform_device *pdev)
 
 	caam_imx = (bool)imx_soc_match;
 
+	ctrlpriv->caam_off_during_pm = caam_imx && caam_off_during_pm();
+
 	if (imx_soc_match) {
 		/*
 		 * Until Layerscape and i.MX OP-TEE get in sync,
@@ -1033,6 +1138,7 @@ static struct platform_driver caam_driver = {
 	.driver = {
 		.name = "caam",
 		.of_match_table = caam_match,
+		.pm = &caam_ctrl_pm_ops,
 	},
 	.probe       = caam_probe,
 };