kernel: nvmem: fix "fixed-layout" & support "mac-base"
DT binding for MAC cells in fixed layout was upstream approved and
accepted. Add support for it. This can replace quite some of our
downstream hacks.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 61f674df4f)
			
			
This commit is contained in:
		@@ -0,0 +1,40 @@
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From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
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Date: Thu, 13 Jul 2023 17:30:59 +0200
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Subject: [PATCH] nvmem: core: fix support for fixed cells NVMEM layout
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Returning -EPROBE_DEFER for "fixed-layout" makes nvmem_register() always
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fail (that layout is supported internally with no external module). That
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makes callers (e.g. mtd_nvmem_add()) fail as well and prevents booting
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on devices with "fixed-layout" in DT.
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Add a quick workaround for it.
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Fixes: 6468a6f45148 ("nvmem: core: handle the absence of expected layouts")
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Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
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---
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--- a/drivers/nvmem/core.c
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+++ b/drivers/nvmem/core.c
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@@ -794,6 +794,19 @@ static struct nvmem_layout *nvmem_layout
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 		return NULL;
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 	/*
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+	 * We should return -EPROBE_DEFER only when layout driver is expected to
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+	 * become available later. Otherwise NVMEM will never probe successfully
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+	 * for unsupported layouts. There is no known solution for that right
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+	 * now.
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+	 *
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+	 * This problem also affects "fixed-layout". It's supported in NVMEM
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+	 * core code so there never will be layout for it. We shouldn't return
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+	 * -EPROBE_DEFER in such case. Add a quick workaround for that.
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+	 */
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+	if (of_device_is_compatible(layout_np, "fixed-layout"))
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+		return NULL;
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+
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+	/*
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 	 * In case the nvmem device was built-in while the layout was built as a
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 	 * module, we shall manually request the layout driver loading otherwise
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 	 * we'll never have any match.
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@@ -0,0 +1,93 @@
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From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
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Date: Thu, 13 Jul 2023 18:29:19 +0200
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Subject: [PATCH] nvmem: core: support "mac-base" fixed layout cells
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Fixed layout binding allows specifying "mac-base" NVMEM cells. It's used
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for base MAC address (that can be used for calculating relative
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addresses). It can be stored in a raw binary format or as an ASCII
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string.
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---
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--- a/drivers/nvmem/Kconfig
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+++ b/drivers/nvmem/Kconfig
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@@ -1,6 +1,7 @@
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 # SPDX-License-Identifier: GPL-2.0-only
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 menuconfig NVMEM
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 	bool "NVMEM Support"
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+	select GENERIC_NET_UTILS
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 	help
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 	  Support for NVMEM(Non Volatile Memory) devices like EEPROM, EFUSES...
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--- a/drivers/nvmem/core.c
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+++ b/drivers/nvmem/core.c
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@@ -7,9 +7,11 @@
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  */
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 #include <linux/device.h>
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+#include <linux/etherdevice.h>
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 #include <linux/export.h>
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 #include <linux/fs.h>
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 #include <linux/idr.h>
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+#include <linux/if_ether.h>
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 #include <linux/init.h>
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 #include <linux/kref.h>
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 #include <linux/module.h>
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@@ -696,6 +698,37 @@ static int nvmem_validate_keepouts(struc
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 	return 0;
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 }
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+static int nvmem_mac_base_raw_read(void *context, const char *id, int index, unsigned int offset,
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+				   void *buf, size_t bytes)
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+{
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+	if (WARN_ON(bytes != ETH_ALEN))
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+		return -EINVAL;
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+
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+	if (index)
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+		eth_addr_add(buf, index);
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+
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+	return 0;
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+}
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+
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+static int nvmem_mac_base_ascii_read(void *context, const char *id, int index, unsigned int offset,
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+				     void *buf, size_t bytes)
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+{
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+	u8 mac[ETH_ALEN];
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+
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+	if (WARN_ON(bytes != 3 * ETH_ALEN - 1))
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+		return -EINVAL;
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+
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+	if (!mac_pton(buf, mac))
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+		return -EINVAL;
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+
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+	if (index)
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+		eth_addr_add(mac, index);
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+
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+	ether_addr_copy(buf, mac);
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+
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+	return 0;
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+}
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+
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 static int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np)
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 {
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 	struct nvmem_layout *layout = nvmem->layout;
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@@ -731,6 +764,20 @@ static int nvmem_add_cells_from_dt(struc
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 		if (layout && layout->fixup_cell_info)
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 			layout->fixup_cell_info(nvmem, layout, &info);
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+		if (of_device_is_compatible(np, "fixed-layout")) {
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+			if (of_device_is_compatible(child, "mac-base")) {
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+				if (info.bytes == 6) {
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+					info.raw_len = info.bytes;
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+					info.bytes = ETH_ALEN;
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+					info.read_post_process = nvmem_mac_base_raw_read;
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+				} else if (info.bytes == 3 * ETH_ALEN - 1) {
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+					info.raw_len = info.bytes;
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+					info.bytes = ETH_ALEN;
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+					info.read_post_process = nvmem_mac_base_ascii_read;
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+				}
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+			}
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+		}
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+
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 		ret = nvmem_add_one_cell(nvmem, &info);
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 		kfree(info.name);
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 		if (ret) {
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