[PATCH] mtd: intel-dg: wake card on operations

[Alexander Usyskin <alexander.usyskin@intel.com>]

Enable runtime PM in mtd driver to notify parent graphics driver
that whole card should be kept awake while nvm operations are
performed through this driver.

CC: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
---
 drivers/mtd/devices/mtd_intel_dg.c | 72 +++++++++++++++++++++++++-----
 1 file changed, 60 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/devices/mtd_intel_dg.c b/drivers/mtd/devices/mtd_intel_dg.c
index b438ee5aacc3..9c8d1405219c 100644
--- a/drivers/mtd/devices/mtd_intel_dg.c
+++ b/drivers/mtd/devices/mtd_intel_dg.c
@@ -15,14 +15,18 @@
 #include <linux/module.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/pm_runtime.h>
 #include <linux/string.h>
 #include <linux/slab.h>
 #include <linux/sizes.h>
 #include <linux/types.h>
 
+#define INTEL_DG_NVM_RPM_TIMEOUT_MS 500
+
 struct intel_dg_nvm {
 	struct kref refcnt;
 	struct mtd_info mtd;
+	struct device *dev;
 	struct mutex lock; /* region access lock */
 	void __iomem *base;
 	void __iomem *base2;
@@ -421,6 +425,8 @@ static int intel_dg_nvm_init(struct intel_dg_nvm *nvm, struct device *device,
 	unsigned int i, n;
 	int ret;
 
+	nvm->dev = device;
+
 	/* clean error register, previous errors are ignored */
 	idg_nvm_error(nvm);
 
@@ -494,6 +500,7 @@ static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
 	size_t total_len;
 	unsigned int idx;
 	ssize_t bytes;
+	int ret = 0;
 	loff_t from;
 	size_t len;
 	u8 region;
@@ -512,20 +519,28 @@ static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
 	total_len = info->len;
 	addr = info->addr;
 
+	ret = pm_runtime_resume_and_get(nvm->dev);
+	if (ret < 0) {
+		dev_err(&mtd->dev, "rpm: get failed %d\n", ret);
+		return ret;
+	}
+
 	guard(mutex)(&nvm->lock);
 
 	while (total_len > 0) {
 		if (!IS_ALIGNED(addr, SZ_4K) || !IS_ALIGNED(total_len, SZ_4K)) {
 			dev_err(&mtd->dev, "unaligned erase %llx %zx\n", addr, total_len);
 			info->fail_addr = addr;
-			return -ERANGE;
+			ret = -ERANGE;
+			break;
 		}
 
 		idx = idg_nvm_get_region(nvm, addr);
 		if (idx >= nvm->nregions) {
 			dev_err(&mtd->dev, "out of range");
 			info->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
-			return -ERANGE;
+			ret = -ERANGE;
+			break;
 		}
 
 		from = addr - nvm->regions[idx].offset;
@@ -541,14 +556,17 @@ static int intel_dg_mtd_erase(struct mtd_info *mtd, struct erase_info *info)
 		if (bytes < 0) {
 			dev_dbg(&mtd->dev, "erase failed with %zd\n", bytes);
 			info->fail_addr += nvm->regions[idx].offset;
-			return bytes;
+			ret = bytes;
+			break;
 		}
 
 		addr += len;
 		total_len -= len;
 	}
 
-	return 0;
+	pm_runtime_mark_last_busy(nvm->dev);
+	pm_runtime_put_autosuspend(nvm->dev);
+	return ret;
 }
 
 static int intel_dg_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
@@ -577,17 +595,25 @@ static int intel_dg_mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
 	if (len > nvm->regions[idx].size - from)
 		len = nvm->regions[idx].size - from;
 
+	ret = pm_runtime_resume_and_get(nvm->dev);
+	if (ret < 0) {
+		dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
+		return ret;
+	}
+
 	guard(mutex)(&nvm->lock);
 
 	ret = idg_read(nvm, region, from, len, buf);
 	if (ret < 0) {
 		dev_dbg(&mtd->dev, "read failed with %zd\n", ret);
-		return ret;
+	} else {
+		*retlen = ret;
+		ret = 0;
 	}
 
-	*retlen = ret;
-
-	return 0;
+	pm_runtime_mark_last_busy(nvm->dev);
+	pm_runtime_put_autosuspend(nvm->dev);
+	return ret;
 }
 
 static int intel_dg_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
@@ -616,17 +642,25 @@ static int intel_dg_mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
 	if (len > nvm->regions[idx].size - to)
 		len = nvm->regions[idx].size - to;
 
+	ret = pm_runtime_resume_and_get(nvm->dev);
+	if (ret < 0) {
+		dev_err(&mtd->dev, "rpm: get failed %zd\n", ret);
+		return ret;
+	}
+
 	guard(mutex)(&nvm->lock);
 
 	ret = idg_write(nvm, region, to, len, buf);
 	if (ret < 0) {
 		dev_dbg(&mtd->dev, "write failed with %zd\n", ret);
-		return ret;
+	} else {
+		*retlen = ret;
+		ret = 0;
 	}
 
-	*retlen = ret;
-
-	return 0;
+	pm_runtime_mark_last_busy(nvm->dev);
+	pm_runtime_put_autosuspend(nvm->dev);
+	return ret;
 }
 
 static void intel_dg_nvm_release(struct kref *kref)
@@ -753,6 +787,17 @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
 	}
 	nvm->nregions = n; /* in case where kasprintf fail */
 
+	devm_pm_runtime_enable(device);
+
+	pm_runtime_set_autosuspend_delay(device, INTEL_DG_NVM_RPM_TIMEOUT_MS);
+	pm_runtime_use_autosuspend(device);
+
+	ret = pm_runtime_resume_and_get(device);
+	if (ret < 0) {
+		dev_err(device, "rpm: get failed %d\n", ret);
+		goto err_norpm;
+	}
+
 	nvm->base = devm_ioremap_resource(device, &invm->bar);
 	if (IS_ERR(nvm->base)) {
 		ret = PTR_ERR(nvm->base);
@@ -781,9 +826,12 @@ static int intel_dg_mtd_probe(struct auxiliary_device *aux_dev,
 
 	dev_set_drvdata(&aux_dev->dev, nvm);
 
+	pm_runtime_put(device);
 	return 0;
 
 err:
+	pm_runtime_put(device);
+err_norpm:
 	kref_put(&nvm->refcnt, intel_dg_nvm_release);
 	return ret;
 }
-- 
2.43.0