[PATCH v2] mtd: spi-nor-core: Add fixups for s25fs512s

[tkuw584924@gmail.com]

From: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>

The current S25FS512S support has following issues that need to be fixed.

  - Non-uniform sectors by factory default. The setting needs to be
    checked and assign erase hook as needed.
  - Page size is wrongly advertised in SFDP.
  - READ_1_1_2 (3Bh/3Ch), READ_1_1_4 (6Bh/6Ch), and PP_1_1_4 (32h/34h)
    are not supported.
  - Bank Address Register (BAR) is not supported.

In addtion, volatile version of Quad Enable is used for safety.

For future use, the fixups is assigned for S25FS-S family.

The datasheet can be found in the following link.
https://www.cypress.com/file/216376/download

Tested on Xilinx Zynq-7000 FPGA board.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
---
Changes in v2:
  - Add #define S25FS_S_RDAR_DUMMY and remove hard-coding
  - Remove #ifdef CONFIG_SPI_FLASH_BAR

 drivers/mtd/spi/spi-nor-core.c | 108 +++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index f1b4e5ea8e..349b2f3f23 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -3099,6 +3099,109 @@ static int spi_nor_setup(struct spi_nor *nor, const struct flash_info *info,
 }
 
 #ifdef CONFIG_SPI_FLASH_SPANSION
+
+/* Number of dummy cycle for Read Any Register (RDAR) op. */
+#define S25FS_S_RDAR_DUMMY	8
+
+static int s25fs_s_quad_enable(struct spi_nor *nor)
+{
+	return spansion_quad_enable_volatile(nor, 0, S25FS_S_RDAR_DUMMY);
+}
+
+static int s25fs_s_erase_non_uniform(struct spi_nor *nor, loff_t addr)
+{
+	/* Support 8 x 4KB sectors at bottom */
+	return spansion_erase_non_uniform(nor, addr, SPINOR_OP_BE_4K_4B, 0,
+					  SZ_32K);
+}
+
+static int s25fs_s_setup(struct spi_nor *nor, const struct flash_info *info,
+			 const struct spi_nor_flash_parameter *params)
+{
+	int ret;
+	u8 cfr3v;
+
+	/* Bank Address Register is not supported */
+	if (CONFIG_IS_ENABLED(SPI_FLASH_BAR))
+		return -ENOTSUPP;
+
+	/*
+	 * Read CR3V to check if uniform sector is selected. If not, assign an
+	 * erase hook that supports non-uniform erase.
+	 */
+	ret = spansion_read_any_reg(nor, SPINOR_REG_ADDR_CFR3V,
+				    S25FS_S_RDAR_DUMMY, &cfr3v);
+	if (ret)
+		return ret;
+	if (!(cfr3v & CFR3V_UNHYSA))
+		nor->erase = s25fs_s_erase_non_uniform;
+
+	return spi_nor_default_setup(nor, info, params);
+}
+
+static void s25fs_s_default_init(struct spi_nor *nor)
+{
+	nor->setup = s25fs_s_setup;
+}
+
+static int s25fs_s_post_bfpt_fixup(struct spi_nor *nor,
+				   const struct sfdp_parameter_header *header,
+				   const struct sfdp_bfpt *bfpt,
+				   struct spi_nor_flash_parameter *params)
+{
+	int ret;
+	u8 cfr3v;
+
+	/* The erase size is set to 4K from BFPT, but it's wrong. Fix it. */
+	nor->erase_opcode = SPINOR_OP_SE;
+	nor->mtd.erasesize = nor->info->sector_size;
+
+	if (params->size > SZ_16M) {
+		ret = nor->write_reg(nor, SPINOR_OP_EN4B, NULL, 0);
+		if (ret)
+			return ret;
+		nor->addr_width = 4;
+	} else {
+		nor->addr_width = 3;
+	}
+
+	/*
+	 * The page_size is set to 512B from BFPT, but it actually depends on
+	 * the configuration register. Look up the CFR3V and determine the
+	 * page_size.
+	 */
+	ret = spansion_read_any_reg(nor, SPINOR_REG_ADDR_CFR3V,
+				    S25FS_S_RDAR_DUMMY, &cfr3v);
+	if (ret)
+		return ret;
+
+	if (cfr3v & CFR3V_PGMBUF)
+		params->page_size = 512;
+	else
+		params->page_size = 256;
+
+	return 0;
+}
+
+static void s25fs_s_post_sfdp_fixup(struct spi_nor *nor,
+				    struct spi_nor_flash_parameter *params)
+{
+	/* READ_1_1_2 is not supported */
+	params->hwcaps.mask &= ~SNOR_HWCAPS_READ_1_1_2;
+	/* READ_1_1_4 is not supported */
+	params->hwcaps.mask &= ~SNOR_HWCAPS_READ_1_1_4;
+	/* PP_1_1_4 is not supported */
+	params->hwcaps.mask &= ~SNOR_HWCAPS_PP_1_1_4;
+	/* Use volatile register to enable quad */
+	params->quad_enable = s25fs_s_quad_enable;
+}
+
+static struct spi_nor_fixups s25fs_s_fixups = {
+	.default_init = s25fs_s_default_init,
+	.post_bfpt = s25fs_s_post_bfpt_fixup,
+	.post_sfdp = s25fs_s_post_sfdp_fixup,
+};
+
 static int s25hx_t_mdp_ready(struct spi_nor *nor)
 {
 	u32 addr;
@@ -3646,6 +3749,11 @@ void spi_nor_set_fixups(struct spi_nor *nor)
 			break;
 		}
 	}
+
+	/* For FS-S (family ID = 0x81)  */
+	if (JEDEC_MFR(nor->info) == SNOR_MFR_SPANSION &&
+	    nor->info->id[5] == 0x81)
+		nor->fixups = &s25fs_s_fixups;
 #endif
 
 #ifdef CONFIG_SPI_FLASH_S28HS512T
-- 
2.25.1