crypto: ccree - simplify Runtime PM handling

Currently, a large part of the probe function runs before Runtime PM is
enabled.  As the driver manages the device's clock manually, this may
work fine on some systems, but may break on platforms with a more
complex power hierarchy.

Fix this by moving the initialization of Runtime PM before the first
register access (in cc_wait_for_reset_completion()), and putting the
device to sleep only after the last access (in cc_set_ree_fips_status()).

This allows to remove the pm_on flag, which was used to track manually
if Runtime PM had been enabled or not.
Remove the cc_pm_{init,go,fini}() wrappers, as they are called only
once, and obscure operation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 26 insertions, 17 deletions

diff --git a/drivers/crypto/ccree/cc_driver.c b/drivers/crypto/ccree/cc_driver.c
index a7b7f65939e2..c7e44f212d4b 100644
--- a/drivers/crypto/ccree/cc_driver.c
+++ b/drivers/crypto/ccree/cc_driver.c
@@ -14,6 +14,7 @@
 #include <linux/of.h>
 #include <linux/clk.h>
 #include <linux/of_address.h>
+#include <linux/pm_runtime.h>
 
 #include "cc_driver.h"
 #include "cc_request_mgr.h"
@@ -360,6 +361,16 @@ static int init_cc_resources(struct platform_device *plat_dev)
 
 	new_drvdata->sec_disabled = cc_sec_disable;
 
+	pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	rc = pm_runtime_get_sync(dev);
+	if (rc < 0) {
+		dev_err(dev, "pm_runtime_get_sync() failed: %d\n", rc);
+		goto post_pm_err;
+	}
+
 	/* wait for Crytpcell reset completion */
 	if (!cc_wait_for_reset_completion(new_drvdata)) {
 		dev_err(dev, "Cryptocell reset not completed");
@@ -372,7 +383,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
 			dev_err(dev, "Invalid CC signature: SIGNATURE=0x%08X != expected=0x%08X\n",
 				val, hw_rev->sig);
 			rc = -EINVAL;
-			goto post_clk_err;
+			goto post_pm_err;
 		}
 		sig_cidr = val;
 		hw_rev_pidr = cc_ioread(new_drvdata, new_drvdata->ver_offset);
@@ -383,7 +394,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
 			dev_err(dev, "Invalid CC PIDR: PIDR0124=0x%08X != expected=0x%08X\n",
 				val,  hw_rev->pidr_0124);
 			rc = -EINVAL;
-			goto post_clk_err;
+			goto post_pm_err;
 		}
 		hw_rev_pidr = val;
 
@@ -392,7 +403,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
 			dev_err(dev, "Invalid CC CIDR: CIDR0123=0x%08X != expected=0x%08X\n",
 			val,  hw_rev->cidr_0123);
 			rc = -EINVAL;
-			goto post_clk_err;
+			goto post_pm_err;
 		}
 		sig_cidr = val;
 
@@ -411,7 +422,7 @@ static int init_cc_resources(struct platform_device *plat_dev)
 		default:
 			dev_err(dev, "Unsupported engines configuration.\n");
 			rc = -EINVAL;
-			goto post_clk_err;
+			goto post_pm_err;
 		}
 
 		/* Check security disable state */
@@ -437,14 +448,14 @@ static int init_cc_resources(struct platform_device *plat_dev)
 			      new_drvdata);
 	if (rc) {
 		dev_err(dev, "Could not register to interrupt %d\n", irq);
-		goto post_clk_err;
+		goto post_pm_err;
 	}
 	dev_dbg(dev, "Registered to IRQ: %d\n", irq);
 
 	rc = init_cc_regs(new_drvdata, true);
 	if (rc) {
 		dev_err(dev, "init_cc_regs failed\n");
-		goto post_clk_err;
+		goto post_pm_err;
 	}
 
 	rc = cc_debugfs_init(new_drvdata);
@@ -483,12 +494,6 @@ static int init_cc_resources(struct platform_device *plat_dev)
 		goto post_req_mgr_err;
 	}
 
-	rc = cc_pm_init(new_drvdata);
-	if (rc) {
-		dev_err(dev, "cc_pm_init failed\n");
-		goto post_buf_mgr_err;
-	}
-
 	/* Allocate crypto algs */
 	rc = cc_cipher_alloc(new_drvdata);
 	if (rc) {
@@ -509,15 +514,13 @@ static int init_cc_resources(struct platform_device *plat_dev)
 		goto post_hash_err;
 	}
 
-	/* All set, we can allow autosuspend */
-	cc_pm_go(new_drvdata);
-
 	/* If we got here and FIPS mode is enabled
 	 * it means all FIPS test passed, so let TEE
 	 * know we're good.
 	 */
 	cc_set_ree_fips_status(new_drvdata, true);
 
+	pm_runtime_put(dev);
 	return 0;
 
 post_hash_err:
@@ -534,7 +537,10 @@ post_debugfs_err:
 	cc_debugfs_fini(new_drvdata);
 post_regs_err:
 	fini_cc_regs(new_drvdata);
-post_clk_err:
+post_pm_err:
+	pm_runtime_put_noidle(dev);
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
 	clk_disable_unprepare(new_drvdata->clk);
 	return rc;
 }
@@ -547,18 +553,21 @@ void fini_cc_regs(struct cc_drvdata *drvdata)
 
 static void cleanup_cc_resources(struct platform_device *plat_dev)
 {
+	struct device *dev = &plat_dev->dev;
 	struct cc_drvdata *drvdata =
 		(struct cc_drvdata *)platform_get_drvdata(plat_dev);
 
 	cc_aead_free(drvdata);
 	cc_hash_free(drvdata);
 	cc_cipher_free(drvdata);
-	cc_pm_fini(drvdata);
 	cc_buffer_mgr_fini(drvdata);
 	cc_req_mgr_fini(drvdata);
 	cc_fips_fini(drvdata);
 	cc_debugfs_fini(drvdata);
 	fini_cc_regs(drvdata);
+	pm_runtime_put_noidle(dev);
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
 	clk_disable_unprepare(drvdata->clk);
 }