[PATCH v4 0/2] Meson: R/W support for pages used by boot ROM

[PATCH v4 0/2] Meson: R/W support for pages used by boot ROM

[Arseniy Krasnov]

Amlogic's boot ROM code needs that some pages on NAND must be written
in special "short" ECC mode with scrambling enabled. Such pages:
1) Contain some metadata about hardware.
2) Located with some interval starting from 0 offset, until some
   specified offset. Interval and second offset are set in the
   device tree.

This patchset adds R/W support for such pages. To enable it we can setup
it in dts:

    nand-is-boot-medium;
    amlogic,boot-page-last = <1024>;
    amlogic,boot-page-step = <128>;

It means that each 128th page in range 0 to 1024 pages will be accessed
in special mode ("short" ECC + scrambling). In practice this feature is
needed when we want to update first block of NAND - driver will enable
required mode by itself using value from device tree.

Changelog:
 v1 -> v2:
  * Rename 'meson,boot-page-XXX' -> 'amlogic,boot-page-XXX'.
  * Add words that 'amlogic,boot-page-step' is measured in pages.
  * Remove words that 'amlogic,boot-page-XXX' depends on 'nand-is-boot-medium'.
  * Make both 'amlogic,boot-page-XXX' depend on each other also, in
    addition to 'nand-is-boot-medium' dependency.
 v2 -> v3:
  * Add quotes to 0001 in dependencies. This fixes 'make dt_binding_check'
    warning.
 v3 -> v4:
  * Rename 'amlogic,boot-page-last' to 'amlogic,boot-pages'.

Arseniy Krasnov (2):
  dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code
  mtd: rawnand: meson: support R/W mode for boot ROM

 .../bindings/mtd/amlogic,meson-nand.yaml      | 14 +++
 drivers/mtd/nand/raw/meson_nand.c             | 88 +++++++++++++------
 2 files changed, 73 insertions(+), 29 deletions(-)

-- 
2.35.0

[PATCH v4 1/2] dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code

[Arseniy Krasnov]

Boot ROM code on Meson requires that some pages on NAND must be written
in special mode: "short" ECC mode where each block is 384 bytes and
scrambling mode is on. Such pages located with the specified interval
within specified offset. Both interval and offset are located in the
device tree and used by driver if 'nand-is-boot-medium' is set for
NAND chip.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
---
 .../bindings/mtd/amlogic,meson-nand.yaml           | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
index 57b6957c8415..838ae1847ef0 100644
--- a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
+++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
@@ -64,11 +64,25 @@ patternProperties:
         items:
           maximum: 0
 
+      amlogic,boot-pages:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          The NFC driver needs this information to select ECC
+          algorithms supported by the boot ROM.
+
+      amlogic,boot-page-step:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          The NFC driver needs this information to select ECC
+          algorithms supported by the boot ROM (in pages).
+
     unevaluatedProperties: false
 
     dependencies:
       nand-ecc-strength: [nand-ecc-step-size]
       nand-ecc-step-size: [nand-ecc-strength]
+      amlogic,boot-pages: [nand-is-boot-medium, "amlogic,boot-page-step"]
+      amlogic,boot-page-step: [nand-is-boot-medium, "amlogic,boot-pages"]
 
 
 required:
-- 
2.35.0

[PATCH v4 2/2] mtd: rawnand: meson: support R/W mode for boot ROM

[Arseniy Krasnov]

Boot ROM code on Meson requires that some pages on NAND must be written
in special mode: "short" ECC mode where each block is 384 bytes and
scrambling mode is on. Such pages located with the specified interval
within specified offset. Both interval and offset are located in the
device tree and used by driver if 'nand-is-boot-medium' is set for
NAND chip.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
---
 drivers/mtd/nand/raw/meson_nand.c | 88 +++++++++++++++++++++----------
 1 file changed, 59 insertions(+), 29 deletions(-)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 00ce0e5bb970..9ee11243b257 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -35,6 +35,7 @@
 #define NFC_CMD_RB		BIT(20)
 #define NFC_CMD_SCRAMBLER_ENABLE	BIT(19)
 #define NFC_CMD_SCRAMBLER_DISABLE	0
+#define NFC_CMD_SHORTMODE_ENABLE	1
 #define NFC_CMD_SHORTMODE_DISABLE	0
 #define NFC_CMD_RB_INT		BIT(14)
 #define NFC_CMD_RB_INT_NO_PIN	((0xb << 10) | BIT(18) | BIT(16))
@@ -78,6 +79,8 @@
 #define DMA_DIR(dir)		((dir) ? NFC_CMD_N2M : NFC_CMD_M2N)
 #define DMA_ADDR_ALIGN		8
 
+#define NFC_SHORT_MODE_ECC_SZ	384
+
 #define ECC_CHECK_RETURN_FF	(-1)
 
 #define NAND_CE0		(0xe << 10)
@@ -125,6 +128,8 @@ struct meson_nfc_nand_chip {
 	u32 twb;
 	u32 tadl;
 	u32 tbers_max;
+	u32 boot_pages;
+	u32 boot_page_step;
 
 	u32 bch_mode;
 	u8 *data_buf;
@@ -298,28 +303,49 @@ static void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
 	       nfc->reg_base + NFC_REG_CMD);
 }
 
-static void meson_nfc_cmd_access(struct nand_chip *nand, int raw, bool dir,
-				 int scrambler)
+static int meson_nfc_page_is_boot(struct nand_chip *nand, int page)
+{
+	const struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+
+	return (nand->options & NAND_IS_BOOT_MEDIUM) &&
+	       !(page % meson_chip->boot_page_step) &&
+	       (page < meson_chip->boot_pages);
+}
+
+static void meson_nfc_cmd_access(struct nand_chip *nand, bool raw, bool dir, int page)
 {
+	const struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
 	struct mtd_info *mtd = nand_to_mtd(nand);
 	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
-	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
-	u32 bch = meson_chip->bch_mode, cmd;
 	int len = mtd->writesize, pagesize, pages;
+	int scrambler;
+	u32 cmd;
 
-	pagesize = nand->ecc.size;
+	if (nand->options & NAND_NEED_SCRAMBLING)
+		scrambler = NFC_CMD_SCRAMBLER_ENABLE;
+	else
+		scrambler = NFC_CMD_SCRAMBLER_DISABLE;
 
 	if (raw) {
 		len = mtd->writesize + mtd->oobsize;
 		cmd = len | scrambler | DMA_DIR(dir);
-		writel(cmd, nfc->reg_base + NFC_REG_CMD);
-		return;
-	}
+	} else if (meson_nfc_page_is_boot(nand, page)) {
+		pagesize = NFC_SHORT_MODE_ECC_SZ >> 3;
+		pages = mtd->writesize / 512;
+
+		scrambler = NFC_CMD_SCRAMBLER_ENABLE;
+		cmd = CMDRWGEN(DMA_DIR(dir), scrambler, NFC_ECC_BCH8_1K,
+			       NFC_CMD_SHORTMODE_ENABLE, pagesize, pages);
+	} else {
+		pagesize = nand->ecc.size >> 3;
+		pages = len / nand->ecc.size;
 
-	pages = len / nand->ecc.size;
+		cmd = CMDRWGEN(DMA_DIR(dir), scrambler, meson_chip->bch_mode,
+			       NFC_CMD_SHORTMODE_DISABLE, pagesize, pages);
+	}
 
-	cmd = CMDRWGEN(DMA_DIR(dir), scrambler, bch,
-		       NFC_CMD_SHORTMODE_DISABLE, pagesize, pages);
+	if (scrambler == NFC_CMD_SCRAMBLER_ENABLE)
+		meson_nfc_cmd_seed(nfc, page);
 
 	writel(cmd, nfc->reg_base + NFC_REG_CMD);
 }
@@ -743,15 +769,7 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand,
 	if (ret)
 		return ret;
 
-	if (nand->options & NAND_NEED_SCRAMBLING) {
-		meson_nfc_cmd_seed(nfc, page);
-		meson_nfc_cmd_access(nand, raw, DIRWRITE,
-				     NFC_CMD_SCRAMBLER_ENABLE);
-	} else {
-		meson_nfc_cmd_access(nand, raw, DIRWRITE,
-				     NFC_CMD_SCRAMBLER_DISABLE);
-	}
-
+	meson_nfc_cmd_access(nand, raw, DIRWRITE, page);
 	cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG;
 	writel(cmd, nfc->reg_base + NFC_REG_CMD);
 	meson_nfc_queue_rb(nand, PSEC_TO_MSEC(sdr->tPROG_max), false);
@@ -829,15 +847,7 @@ static int meson_nfc_read_page_sub(struct nand_chip *nand,
 	if (ret)
 		return ret;
 
-	if (nand->options & NAND_NEED_SCRAMBLING) {
-		meson_nfc_cmd_seed(nfc, page);
-		meson_nfc_cmd_access(nand, raw, DIRREAD,
-				     NFC_CMD_SCRAMBLER_ENABLE);
-	} else {
-		meson_nfc_cmd_access(nand, raw, DIRREAD,
-				     NFC_CMD_SCRAMBLER_DISABLE);
-	}
-
+	meson_nfc_cmd_access(nand, raw, DIRREAD, page);
 	ret = meson_nfc_wait_dma_finish(nfc);
 	meson_nfc_check_ecc_pages_valid(nfc, nand, raw);
 
@@ -1436,6 +1446,26 @@ meson_nfc_nand_chip_init(struct device *dev,
 	if (ret)
 		return ret;
 
+	if (nand->options & NAND_IS_BOOT_MEDIUM) {
+		ret = of_property_read_u32(np, "amlogic,boot-pages",
+					   &meson_chip->boot_pages);
+		if (ret) {
+			dev_err(dev, "could not retrieve 'amlogic,boot-pages' property: %d",
+				ret);
+			nand_cleanup(nand);
+			return ret;
+		}
+
+		ret = of_property_read_u32(np, "amlogic,boot-page-step",
+					   &meson_chip->boot_page_step);
+		if (ret) {
+			dev_err(dev, "could not retrieve 'amlogic,boot-page-step' property: %d",
+				ret);
+			nand_cleanup(nand);
+			return ret;
+		}
+	}
+
 	ret = mtd_device_register(mtd, NULL, 0);
 	if (ret) {
 		dev_err(dev, "failed to register MTD device: %d\n", ret);
-- 
2.35.0

Re: [PATCH v4 1/2] dt-bindings: mtd: amlogic,meson-nand: support fields for boot ROM code

[Rob Herring]

On Wed, Apr 10, 2024 at 09:54:08PM +0300, Arseniy Krasnov wrote:
> Boot ROM code on Meson requires that some pages on NAND must be written
> in special mode: "short" ECC mode where each block is 384 bytes and
> scrambling mode is on. Such pages located with the specified interval
> within specified offset. Both interval and offset are located in the
> device tree and used by driver if 'nand-is-boot-medium' is set for
> NAND chip.
> 
> Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
> ---
>  .../bindings/mtd/amlogic,meson-nand.yaml           | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> index 57b6957c8415..838ae1847ef0 100644
> --- a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> +++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.yaml
> @@ -64,11 +64,25 @@ patternProperties:
>          items:
>            maximum: 0
>  
> +      amlogic,boot-pages:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description:
> +          The NFC driver needs this information to select ECC
> +          algorithms supported by the boot ROM.

'the $driver drivers needs this information' is true for every property, 
so it's redundant. You fail to say *what* the property represents or 
defines.

> +
> +      amlogic,boot-page-step:
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        description:
> +          The NFC driver needs this information to select ECC
> +          algorithms supported by the boot ROM (in pages).

Same issue here.

> +
>      unevaluatedProperties: false
>  
>      dependencies:
>        nand-ecc-strength: [nand-ecc-step-size]
>        nand-ecc-step-size: [nand-ecc-strength]
> +      amlogic,boot-pages: [nand-is-boot-medium, "amlogic,boot-page-step"]
> +      amlogic,boot-page-step: [nand-is-boot-medium, "amlogic,boot-pages"]
>  
>  
>  required:
> -- 
> 2.35.0
>