[PATCH v2 0/2] pinctrl: mcp23s08: Fix probe issues

[PATCH v2 0/2] pinctrl: mcp23s08: Fix probe issues

[Judith Mendez]

MCP23S18 driver probe failures on AM62L3 BeagleBadge[0].

Fix MCP23S18 probe failures found with BeagleBadge which has a MCP23S18
on board chip. Fixes are made up of initializing chip data before regmap
init, and using device_property_read_u8 to match binding spec. First fix
prevents kernel oops and second fix prevents MCP chip probe failure.

[0] https://github.com/beagleboard/BeagleBadge

Changes since v1:
- Add #define for base address & use instead of 0x40 hardcode base address
- Add patch 2/2

Judith Mendez (2):
  pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap
    init
  pinctrl: mcp23s08: Read spi-present-mask as u8 not u32

 drivers/pinctrl/pinctrl-mcp23s08_spi.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

-- 
2.54.0

[PATCH v2 1/2] pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap init

[Judith Mendez]

Regmap initialization triggers regcache_maple_populate() which attempts
SPI read to populate cache. SPI read requires mcp->dev and mcp->addr to
be set, without them, NULL pointer dereference occurs during probe.

Move initialization before mcp23s08_spi_regmap_init() call.

Cc: stable@vger.kernel.org
Fixes: f9f4fda15e72 ("pinctrl: mcp23s08: init reg_defaults from HW at probe and switch cache type")
Signed-off-by: Judith Mendez <jm@ti.com>
---
Changes since v1:
- Add #define for base adress & use instead of 0x40 hardcode base address
---
 drivers/pinctrl/pinctrl-mcp23s08_spi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/pinctrl-mcp23s08_spi.c b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
index 54f61c8cb1c0f..5ed368772adb7 100644
--- a/drivers/pinctrl/pinctrl-mcp23s08_spi.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
@@ -10,6 +10,7 @@
 #include "pinctrl-mcp23s08.h"
 
 #define MCP_MAX_DEV_PER_CS	8
+#define MCP23S08_SPI_BASE	0x40
 
 /*
  * A given spi_device can represent up to eight mcp23sxx chips
@@ -173,6 +174,8 @@ static int mcp23s08_probe(struct spi_device *spi)
 	for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
 		data->mcp[addr] = &data->chip[--chips];
 		data->mcp[addr]->irq = spi->irq;
+		data->mcp[addr]->dev = dev;
+		data->mcp[addr]->addr = MCP23S08_SPI_BASE | (addr << 1);
 
 		ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, info);
 		if (ret)
@@ -184,7 +187,7 @@ static int mcp23s08_probe(struct spi_device *spi)
 		if (!data->mcp[addr]->pinctrl_desc.name)
 			return -ENOMEM;
 
-		ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1),
+		ret = mcp23s08_probe_one(data->mcp[addr], dev, MCP23S08_SPI_BASE | (addr << 1),
 					 info->type, -1);
 		if (ret < 0)
 			return ret;
-- 
2.54.0

[PATCH v2 2/2] pinctrl: mcp23s08: Read spi-present-mask as u8 not u32

[Judith Mendez]

The binding (microchip,mcp23s08) specifies microchip,spi-present-mask
as uint8, but driver would read u32, causing type mismatch. Use
device_property_read_u8 to match binding spec, hardware (8 chips max),
& prevent probe failure.

Cc: stable@vger.kernel.org
Fixes: 3ad8d3ec6d87 ("dt-bindings: pinctrl: convert pinctrl-mcp23s08.txt to yaml format")
Signed-off-by: Judith Mendez <jm@ti.com>
---
Changes since v1:
- Add patch 2/2
---
 drivers/pinctrl/pinctrl-mcp23s08_spi.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-mcp23s08_spi.c b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
index 5ed368772adb7..30775d31bd694 100644
--- a/drivers/pinctrl/pinctrl-mcp23s08_spi.c
+++ b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
@@ -144,13 +144,13 @@ static int mcp23s08_probe(struct spi_device *spi)
 	unsigned int addr;
 	int chips;
 	int ret;
-	u32 v;
+	u8 v;
 
 	info = spi_get_device_match_data(spi);
 
-	ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
+	ret = device_property_read_u8(dev, "microchip,spi-present-mask", &v);
 	if (ret) {
-		ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
+		ret = device_property_read_u8(dev, "mcp,spi-present-mask", &v);
 		if (ret) {
 			dev_err(dev, "missing spi-present-mask");
 			return ret;
-- 
2.54.0