[PATCH v2 01/14] spi: spi-fsl-dspi: restrict register range for regmap access

[James Clark]

From: Larisa Grigore <larisa.grigore at nxp.com>

DSPI registers are NOT continuous, some registers are reserved and
accessing them from userspace will trigger external abort, add regmap
register access table to avoid below abort.

  For example on S32G:

  # cat /sys/kernel/debug/regmap/401d8000.spi/registers

  Internal error: synchronous external abort: 96000210 1 PREEMPT SMP
  ...
  Call trace:
  regmap_mmio_read32le+0x24/0x48
  regmap_mmio_read+0x48/0x70
  _regmap_bus_reg_read+0x38/0x48
  _regmap_read+0x68/0x1b0
  regmap_read+0x50/0x78
  regmap_read_debugfs+0x120/0x338

Fixes: 1acbdeb92c87 ("spi/fsl-dspi: Convert to use regmap and add big-endian support")
Co-developed-by: Xulin Sun <xulin.sun at windriver.com>
Signed-off-by: Xulin Sun <xulin.sun at windriver.com>
Signed-off-by: Larisa Grigore <larisa.grigore at nxp.com>
Signed-off-by: James Clark <james.clark at linaro.org>
---
 drivers/spi/spi-fsl-dspi.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 067c954cb6ea..effb460d436d 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0+
 //
 // Copyright 2013 Freescale Semiconductor, Inc.
-// Copyright 2020 NXP
+// Copyright 2020-2025 NXP
 //
 // Freescale DSPI driver
 // This file contains a driver for the Freescale DSPI
@@ -1167,6 +1167,20 @@ static int dspi_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
 
+static const struct regmap_range dspi_yes_ranges[] = {
+	regmap_reg_range(SPI_MCR, SPI_MCR),
+	regmap_reg_range(SPI_TCR, SPI_CTAR(3)),
+	regmap_reg_range(SPI_SR, SPI_TXFR3),
+	regmap_reg_range(SPI_RXFR0, SPI_RXFR3),
+	regmap_reg_range(SPI_CTARE(0), SPI_CTARE(3)),
+	regmap_reg_range(SPI_SREX, SPI_SREX),
+};
+
+static const struct regmap_access_table dspi_access_table = {
+	.yes_ranges	= dspi_yes_ranges,
+	.n_yes_ranges	= ARRAY_SIZE(dspi_yes_ranges),
+};
+
 static const struct regmap_range dspi_volatile_ranges[] = {
 	regmap_reg_range(SPI_MCR, SPI_TCR),
 	regmap_reg_range(SPI_SR, SPI_SR),
@@ -1184,6 +1198,8 @@ static const struct regmap_config dspi_regmap_config = {
 	.reg_stride	= 4,
 	.max_register	= 0x88,
 	.volatile_table	= &dspi_volatile_table,
+	.rd_table	= &dspi_access_table,
+	.wr_table	= &dspi_access_table,
 };
 
 static const struct regmap_range dspi_xspi_volatile_ranges[] = {
@@ -1205,6 +1221,8 @@ static const struct regmap_config dspi_xspi_regmap_config[] = {
 		.reg_stride	= 4,
 		.max_register	= 0x13c,
 		.volatile_table	= &dspi_xspi_volatile_table,
+		.rd_table	= &dspi_access_table,
+		.wr_table	= &dspi_access_table,
 	},
 	{
 		.name		= "pushr",

-- 
2.34.1