driver: flash: mcux_flexspi_nor: Second attempt to fix is25lpXXX chips

This commit changes the implementation to distinguish between is25lpXXX
and is25lpXXXd. Using RDERP as in the original solution didn't work for
is25wpXXX chips and would cause a halt. This new implementation reads
the AutoBoot register instead, which is not present in is25lpXXX but
present in is25lpXXXd, is25wpXXX and is25wpXXXd.

Tested on:
- mimxrt1020-evk
- mimxrt1170-evk rev. A
- custom board with mimxrt1170 and is25lp128d

Signed-off-by: John Barbero Unenge <git@lsrkttn.com>

Author: JBarberU

drivers/flash/flash_mcux_flexspi_nor.c

@@ -970,20 +970,20 @@ flash_flexspi_nor_is25_clear_dummy_cycles(struct flash_flexspi_nor_data *data,
 	};
 
 	/*
-	 * Get Extended Read Parameters (Non-Volatile) command (RDERP, 81h)
+	 * Read AutoBoot Register command (RDABR, 14h)
 	 *
 	 * This is done to distinguish between an IS25LPXXX and IS25LPXXXD since
 	 * the former uses the read parameters (SRPV) to set drive strength and
 	 * dummy cycles, while IS25LPXXXD uses extended read parameters (SERPV)
 	 * for drive strength and read parameters (SRPV) for dummy cycles.
 	 */
-	uint32_t resp_data;
+	uint32_t resp_data = 0;
 
 	transfer.data = &resp_data;
 	transfer.cmdType = kFLEXSPI_Read;
 
 	flexspi_lut[SCRATCH_CMD][0] =
-		FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x81,
+		FLEXSPI_LUT_SEQ(kFLEXSPI_Command_SDR, kFLEXSPI_1PAD, 0x14,
 				kFLEXSPI_Command_READ_SDR, kFLEXSPI_1PAD, 0x1);
 	ret = memc_flexspi_set_device_config(&data->controller, &config, (uint32_t *)flexspi_lut,
 					     FLEXSPI_INSTR_END * MEMC_FLEXSPI_CMD_PER_SEQ,
@@ -996,12 +996,12 @@ flash_flexspi_nor_is25_clear_dummy_cycles(struct flash_flexspi_nor_data *data,
 	ret = memc_flexspi_transfer(&data->controller, &transfer);
 
 	/*
-	 * Check that EB[7:4] is not all zero and that EB[0] (WIP)
-	 * is not 1, which should catch a chip responding to an
-	 * unsupported 81h command with either 0x00 or 0xFF
+	 * IS25LPXXX -> 0xff
+	 * IS25WPXXX -> 0
+	 * IS25LPXXXD -> 0
+	 * IS25WPXXXD -> 0
 	 */
-	const int has_extended_read_reg = resp_data & 0xF0 && !(resp_data & 0x01);
-	uint32_t read_params = has_extended_read_reg ? 0 : 0xE0U;
+	uint32_t read_params = resp_data == 0xff ? 0xE0U : 0;
 
 	/* Switch over to writing read_params (SRPV, C0h) */
 	transfer.cmdType = kFLEXSPI_Write;