mediatek: v5.15: backport spi-mem ecc support

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>

1 files changed, 224 insertions, 0 deletions

diff --git a/target/linux/mediatek/patches-5.15/120-01-v5.18-mtd-nand-ecc-Add-infrastructure-to-support-hardware-.patch b/target/linux/mediatek/patches-5.15/120-01-v5.18-mtd-nand-ecc-Add-infrastructure-to-support-hardware-.patch
new file mode 100644
index 0000000000..b6b069d234
--- /dev/null
+++ b/target/linux/mediatek/patches-5.15/120-01-v5.18-mtd-nand-ecc-Add-infrastructure-to-support-hardware-.patch
@@ -0,0 +1,224 @@
+From ad4944aa0b02cb043afe20bc2a018c161e65c992 Mon Sep 17 00:00:00 2001
+From: Miquel Raynal <miquel.raynal@bootlin.com>
+Date: Thu, 16 Dec 2021 12:16:38 +0100
+Subject: [PATCH 01/15] mtd: nand: ecc: Add infrastructure to support hardware
+ engines
+
+Add the necessary helpers to register/unregister hardware ECC engines
+that will be called from ECC engine drivers.
+
+Also add helpers to get the right engine from the user
+perspective. Keep a reference of the in use ECC engine in order to
+prevent modules to be unloaded. Put the reference when the engine gets
+retired.
+
+A static list of hardware (only) ECC engines is setup to keep track of
+the registered engines.
+
+Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
+Link: https://lore.kernel.org/linux-mtd/20211216111654.238086-13-miquel.raynal@bootlin.com
+(cherry picked from commit 96489c1c0b53131b0e1ec33e2060538379ad6152)
+---
+ drivers/mtd/nand/core.c  | 10 +++--
+ drivers/mtd/nand/ecc.c   | 88 ++++++++++++++++++++++++++++++++++++++++
+ include/linux/mtd/nand.h | 28 +++++++++++++
+ 3 files changed, 123 insertions(+), 3 deletions(-)
+
+diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c
+index 5e13a03d2b32..b228b4d13b7a 100644
+--- a/drivers/mtd/nand/core.c
++++ b/drivers/mtd/nand/core.c
+@@ -232,7 +232,9 @@ static int nanddev_get_ecc_engine(struct nand_device *nand)
+ 		nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand);
+ 		break;
+ 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
+-		pr_err("On-host hardware ECC engines not supported yet\n");
++		nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand);
++		if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER)
++			return -EPROBE_DEFER;
+ 		break;
+ 	default:
+ 		pr_err("Missing ECC engine type\n");
+@@ -252,7 +254,7 @@ static int nanddev_put_ecc_engine(struct nand_device *nand)
+ {
+ 	switch (nand->ecc.ctx.conf.engine_type) {
+ 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
+-		pr_err("On-host hardware ECC engines not supported yet\n");
++		nand_ecc_put_on_host_hw_engine(nand);
+ 		break;
+ 	case NAND_ECC_ENGINE_TYPE_NONE:
+ 	case NAND_ECC_ENGINE_TYPE_SOFT:
+@@ -297,7 +299,9 @@ int nanddev_ecc_engine_init(struct nand_device *nand)
+ 	/* Look for the ECC engine to use */
+ 	ret = nanddev_get_ecc_engine(nand);
+ 	if (ret) {
+-		pr_err("No ECC engine found\n");
++		if (ret != -EPROBE_DEFER)
++			pr_err("No ECC engine found\n");
++
+ 		return ret;
+ 	}
+ 
+diff --git a/drivers/mtd/nand/ecc.c b/drivers/mtd/nand/ecc.c
+index 6c43dfda01d4..078f5ec38de3 100644
+--- a/drivers/mtd/nand/ecc.c
++++ b/drivers/mtd/nand/ecc.c
+@@ -96,6 +96,12 @@
+ #include <linux/module.h>
+ #include <linux/mtd/nand.h>
+ #include <linux/slab.h>
++#include <linux/of.h>
++#include <linux/of_device.h>
++#include <linux/of_platform.h>
++
++static LIST_HEAD(on_host_hw_engines);
++static DEFINE_MUTEX(on_host_hw_engines_mutex);
+ 
+ /**
+  * nand_ecc_init_ctx - Init the ECC engine context
+@@ -611,6 +617,88 @@ struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand)
+ }
+ EXPORT_SYMBOL(nand_ecc_get_on_die_hw_engine);
+ 
++int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine)
++{
++	struct nand_ecc_engine *item;
++
++	if (!engine)
++		return -EINVAL;
++
++	/* Prevent multiple registrations of one engine */
++	list_for_each_entry(item, &on_host_hw_engines, node)
++		if (item == engine)
++			return 0;
++
++	mutex_lock(&on_host_hw_engines_mutex);
++	list_add_tail(&engine->node, &on_host_hw_engines);
++	mutex_unlock(&on_host_hw_engines_mutex);
++
++	return 0;
++}
++EXPORT_SYMBOL(nand_ecc_register_on_host_hw_engine);
++
++int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine)
++{
++	if (!engine)
++		return -EINVAL;
++
++	mutex_lock(&on_host_hw_engines_mutex);
++	list_del(&engine->node);
++	mutex_unlock(&on_host_hw_engines_mutex);
++
++	return 0;
++}
++EXPORT_SYMBOL(nand_ecc_unregister_on_host_hw_engine);
++
++static struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev)
++{
++	struct nand_ecc_engine *item;
++
++	list_for_each_entry(item, &on_host_hw_engines, node)
++		if (item->dev == dev)
++			return item;
++
++	return NULL;
++}
++
++struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand)
++{
++	struct nand_ecc_engine *engine = NULL;
++	struct device *dev = &nand->mtd.dev;
++	struct platform_device *pdev;
++	struct device_node *np;
++
++	if (list_empty(&on_host_hw_engines))
++		return NULL;
++
++	/* Check for an explicit nand-ecc-engine property */
++	np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0);
++	if (np) {
++		pdev = of_find_device_by_node(np);
++		if (!pdev)
++			return ERR_PTR(-EPROBE_DEFER);
++
++		engine = nand_ecc_match_on_host_hw_engine(&pdev->dev);
++		platform_device_put(pdev);
++		of_node_put(np);
++
++		if (!engine)
++			return ERR_PTR(-EPROBE_DEFER);
++	}
++
++	if (engine)
++		get_device(engine->dev);
++
++	return engine;
++}
++EXPORT_SYMBOL(nand_ecc_get_on_host_hw_engine);
++
++void nand_ecc_put_on_host_hw_engine(struct nand_device *nand)
++{
++	put_device(nand->ecc.engine->dev);
++}
++EXPORT_SYMBOL(nand_ecc_put_on_host_hw_engine);
++
+ MODULE_LICENSE("GPL");
+ MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
+ MODULE_DESCRIPTION("Generic ECC engine");
+diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
+index 32fc7edf65b3..4ddd20fe9c9e 100644
+--- a/include/linux/mtd/nand.h
++++ b/include/linux/mtd/nand.h
+@@ -263,12 +263,36 @@ struct nand_ecc_engine_ops {
+ 			     struct nand_page_io_req *req);
+ };
+ 
++/**
++ * enum nand_ecc_engine_integration - How the NAND ECC engine is integrated
++ * @NAND_ECC_ENGINE_INTEGRATION_INVALID: Invalid value
++ * @NAND_ECC_ENGINE_INTEGRATION_PIPELINED: Pipelined engine, performs on-the-fly
++ *                                         correction, does not need to copy
++ *                                         data around
++ * @NAND_ECC_ENGINE_INTEGRATION_EXTERNAL: External engine, needs to bring the
++ *                                        data into its own area before use
++ */
++enum nand_ecc_engine_integration {
++	NAND_ECC_ENGINE_INTEGRATION_INVALID,
++	NAND_ECC_ENGINE_INTEGRATION_PIPELINED,
++	NAND_ECC_ENGINE_INTEGRATION_EXTERNAL,
++};
++
+ /**
+  * struct nand_ecc_engine - ECC engine abstraction for NAND devices
++ * @dev: Host device
++ * @node: Private field for registration time
+  * @ops: ECC engine operations
++ * @integration: How the engine is integrated with the host
++ *               (only relevant on %NAND_ECC_ENGINE_TYPE_ON_HOST engines)
++ * @priv: Private data
+  */
+ struct nand_ecc_engine {
++	struct device *dev;
++	struct list_head node;
+ 	struct nand_ecc_engine_ops *ops;
++	enum nand_ecc_engine_integration integration;
++	void *priv;
+ };
+ 
+ void of_get_nand_ecc_user_config(struct nand_device *nand);
+@@ -279,8 +303,12 @@ int nand_ecc_prepare_io_req(struct nand_device *nand,
+ int nand_ecc_finish_io_req(struct nand_device *nand,
+ 			   struct nand_page_io_req *req);
+ bool nand_ecc_is_strong_enough(struct nand_device *nand);
++int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine);
++int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine);
+ struct nand_ecc_engine *nand_ecc_get_sw_engine(struct nand_device *nand);
+ struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand);
++struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand);
++void nand_ecc_put_on_host_hw_engine(struct nand_device *nand);
+ 
+ #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING)
+ struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);
+-- 
+2.35.1
+