bcm53xx: add support for reading NVRAM based on DT mapping

[openwrt/openwrt.git] / target / linux / bcm53xx / patches-5.4 / 181-0002-firmware-bcm47xx_nvram-support-platform-device-brcm-.patch

diff --git a/target/linux/bcm53xx/patches-5.4/181-0002-firmware-bcm47xx_nvram-support-platform-device-brcm-.patch b/target/linux/bcm53xx/patches-5.4/181-0002-firmware-bcm47xx_nvram-support-platform-device-brcm-.patch
new file mode 100644 (file)
index 0000000..c1dea1f
--- /dev/null
+++ b/target/linux/bcm53xx/patches-5.4/181-0002-firmware-bcm47xx_nvram-support-platform-device-brcm-.patch
@@ -0,0 +1,85 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Tue, 2 Mar 2021 08:33:13 +0100
+Subject: [PATCH] firmware: bcm47xx_nvram: support platform device "brcm,nvram"
+
+Add support for platform device providing mapping resource. This allows
+reading NVRAM based on DT mapping binding. It's required for devices
+that boot depending on NVRAM stored setup and provides early access to
+NVRAM data.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/firmware/broadcom/bcm47xx_nvram.c | 55 +++++++++++++++++++++++
+ 1 file changed, 55 insertions(+)
+
+--- a/drivers/firmware/broadcom/bcm47xx_nvram.c
++++ b/drivers/firmware/broadcom/bcm47xx_nvram.c
+@@ -13,6 +13,7 @@
+ #include <linux/kernel.h>
+ #include <linux/string.h>
+ #include <linux/mtd/mtd.h>
++#include <linux/platform_device.h>
+ #include <linux/bcm47xx_nvram.h>
+ 
+ #define NVRAM_MAGIC                   0x48534C46      /* 'FLSH' */
+@@ -162,6 +163,60 @@ static int nvram_init(void)
+       return -ENXIO;
+ }
+ 
++static int brcm_nvram_probe(struct platform_device *pdev)
++{
++      struct nvram_header __iomem *header;
++      struct device *dev = &pdev->dev;
++      struct resource *res;
++      void __iomem *mmio;
++      size_t copy_len;
++
++      res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++      if (!res) {
++              dev_err(dev, "Failed to get resource\n");
++              return -ENODEV;
++      }
++
++      mmio = ioremap(res->start, resource_size(res));
++      if (!mmio)
++              return -ENOMEM;
++
++      header = (struct nvram_header *)mmio;
++      copy_len = DIV_ROUND_UP(sizeof(*header) + header->len, 4);
++      if (header->magic != NVRAM_MAGIC) {
++              dev_err(dev, "No NVRAM found at %pR\n", res);
++              return -EPROTO;
++      } else if (copy_len > resource_size(res)) {
++              dev_err(dev, "NVRAM size exceeds %pR\n", res);
++              return -ERANGE;
++      } else if (copy_len >= NVRAM_SPACE) {
++              dev_err(dev, "NVRAM size exceeds buffer size %d\n", NVRAM_SPACE);
++              return -ENOMEM;
++      }
++
++      __ioread32_copy(nvram_buf, mmio, copy_len);
++      nvram_buf[NVRAM_SPACE - 1] = '\0';
++
++      iounmap(mmio);
++
++      return 0;
++}
++
++static const struct of_device_id brcm_nvram_of_match[] = {
++      { .compatible = "brcm,nvram "},
++      {},
++};
++
++static struct platform_driver brcm_nvram_driver = {
++      .driver = {
++              .name = "brcm_nvram",
++              .of_match_table = brcm_nvram_of_match,
++      },
++      .probe  = brcm_nvram_probe,
++};
++
++module_platform_driver(brcm_nvram_driver);
++
+ int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len)
+ {
+       char *var, *value, *end, *eq;