drivers: flash: provide api to reset the flash registers

changes enable flash driver to provide api interface to send reset memory spi command to the spi flash. The reset memory command would bring the spi flash to its default power-on state and loose all the volatile register settings. Flash reset is needed when more than one controller access the flash chip in a shared mode. Signed-off-by: Deepti Deshatty <[email protected]>
zephyrproject-rtos · Oct 20, 2023 · 6d0c9e0 · 6d0c9e0
1 parent 90b9809
commit 6d0c9e0
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diff --git a/drivers/flash/Kconfig.nor b/drivers/flash/Kconfig.nor
@@ -8,6 +8,7 @@ menuconfig SPI_NOR
 	select FLASH_HAS_DRIVER_ENABLED
 	select FLASH_HAS_PAGE_LAYOUT
 	select FLASH_JESD216
+	select FLASH_HAS_EX_OP
 	select SPI
 
 if SPI_NOR

diff --git a/drivers/flash/spi_nor.c b/drivers/flash/spi_nor.c
@@ -702,6 +702,34 @@ static int spi_nor_read(const struct device *dev, off_t addr, void *dest,
 	return ret;
 }
 
+#if defined(CONFIG_FLASH_EX_OP_ENABLED)
+static int flash_spi_nor_ex_op(const struct device *dev, uint16_t code,
+			const uintptr_t in, void *out)
+{
+	int ret;
+
+	ARG_UNUSED(in);
+	ARG_UNUSED(out);
+
+	acquire_device(dev);
+
+	switch (code) {
+	case FLASH_EX_OP_RESET:
+		ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_RESET_EN);
+		if (ret == 0) {
+			ret = spi_nor_cmd_write(dev, SPI_NOR_CMD_RESET_MEM);
+		}
+		break;
+	default:
+		ret = -ENOTSUP;
+		break;
+	}
+
+	release_device(dev);
+	return ret;
+}
+#endif
+
 static int spi_nor_write(const struct device *dev, off_t addr,
 			 const void *src,
 			 size_t size)
@@ -1426,6 +1454,9 @@ static const struct flash_driver_api spi_nor_api = {
 	.sfdp_read = spi_nor_sfdp_read,
 	.read_jedec_id = spi_nor_read_jedec_id,
 #endif
+#if defined(CONFIG_FLASH_EX_OP_ENABLED)
+	.ex_op = flash_spi_nor_ex_op,
+#endif
 };
 
 #ifndef CONFIG_SPI_NOR_SFDP_RUNTIME

diff --git a/include/zephyr/drivers/flash.h b/include/zephyr/drivers/flash.h
@@ -471,6 +471,16 @@ __syscall int flash_ex_op(const struct device *dev, uint16_t code,
 #define FLASH_EX_OP_VENDOR_BASE 0x8000
 #define FLASH_EX_OP_IS_VENDOR(c) ((c) & FLASH_EX_OP_VENDOR_BASE)
 
+/**
+ *  @brief Enumeration for extra flash operations
+ */
+enum flash_ex_op_types {
+	/*
+	 * Reset flash device.
+	 */
+	FLASH_EX_OP_RESET = 0,
+};
+
 static inline int z_impl_flash_ex_op(const struct device *dev, uint16_t code,
 				     const uintptr_t in, void *out)
 {