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 18, 2023 · 7048e48 · 7048e48
1 parent 90b9809
commit 7048e48
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diff --git a/drivers/flash/spi_nor.c b/drivers/flash/spi_nor.c
@@ -702,6 +702,33 @@ 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 = 0;
+
+	ARG_UNUSED(in);
+	ARG_UNUSED(out);
+
+	acquire_device(dev);
+
+	switch (code) {
+	case FLASH_SPI_NOR_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 +1453,9 @@ 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/drivers/flash/spi_nor.h b/drivers/flash/spi_nor.h
@@ -7,8 +7,16 @@
 #ifndef __SPI_NOR_H__
 #define __SPI_NOR_H__
 
+#include <zephyr/drivers/flash.h>
 #include <zephyr/sys/util.h>
 
+enum flash_spi_nor_ops {
+	/*
+	 * Sends Flash reset SPI commands to reset the flash device.
+	 */
+	FLASH_SPI_NOR_RESET = FLASH_EX_OP_VENDOR_BASE,
+};
+
 #define SPI_NOR_MAX_ID_LEN	3
 
 /* Status register bits */