From 6217924a0127d073ac753c862a62c752320aa151 Mon Sep 17 00:00:00 2001
From: Daniel Danzberger
Date: Tue, 5 Dec 2023 12:08:16 +0100
Subject: [PATCH] net: dsa: microchip: properly support platform_data probing
The ksz driver has bits and pieces of platform_data probing support, but
it doesn't work.
The conventional thing to do is to have an encapsulating structure for
struct dsa_chip_data that gets put into dev->platform_data. This driver
expects a struct ksz_platform_data, but that doesn't contain a struct
dsa_chip_data as first element, which will obviously not work with
dsa_switch_probe() -> dsa_switch_parse().
Pointing dev->platform_data to a struct dsa_chip_data directly is in
principle possible, but that doesn't work either. The driver has
ksz_switch_detect() to read the device ID from hardware, followed by
ksz_check_device_id() to compare it against a predetermined expected
value. This protects against early errors in the SPI/I2C communication.
With platform_data, the mechanism in ksz_check_device_id() doesn't work
and even leads to NULL pointer dereferences, since of_device_get_match_data()
doesn't work in that probe path.
So obviously, the platform_data support is actually missing, and the
existing handling of struct ksz_platform_data is bogus. Complete the
support by adding a struct dsa_chip_data as first element, and fixing up
ksz_check_device_id() to pick up the platform_data instead of the
unavailable of_device_get_match_data().
The early dev->chip_id assignment from ksz_switch_register() is also
bogus, because ksz_switch_detect() sets it to an initial value. So
remove it.
Also, ksz_platform_data :: enabled_ports isn't used anywhere, delete it.
---
drivers/net/dsa/microchip/ksz_common.c | 21 ++++++++++++--------
drivers/net/dsa/microchip/ksz_common.h | 19 +-----------------
include/linux/platform_data/microchip-ksz.h | 22 ++++++++++++++++++++-
3 files changed, 35 insertions(+), 27 deletions(-)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index dc9eea3c8..248dc034d 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -1457,15 +1457,23 @@ static const struct ksz_chip_data *ksz_lookup_info(unsigned int prod_num)
static int ksz_check_device_id(struct ksz_device *dev)
{
- const struct ksz_chip_data *dt_chip_data;
+ const struct ksz_chip_data *expected_chip_data;
+ u32 expected_chip_id;
- dt_chip_data = of_device_get_match_data(dev->dev);
+ if (dev->pdata) {
+ expected_chip_id = dev->pdata->chip_id;
+ expected_chip_data = ksz_lookup_info(expected_chip_id);
+ if (WARN_ON(!expected_chip_data))
+ return -ENODEV;
+ } else {
+ expected_chip_data = of_device_get_match_data(dev->dev);
+ expected_chip_id = expected_chip_data->chip_id;
+ }
- /* Check for Device Tree and Chip ID */
- if (dt_chip_data->chip_id != dev->chip_id) {
+ if (expected_chip_id != dev->chip_id) {
dev_err(dev->dev,
"Device tree specifies chip %s but found %s, please fix it!\n",
- dt_chip_data->dev_name, dev->info->dev_name);
+ expected_chip_data->dev_name, dev->info->dev_name);
return -ENODEV;
}
@@ -2900,9 +2908,6 @@ int ksz_switch_register(struct ksz_device *dev)
int ret;
int i;
- if (dev->pdata)
- dev->chip_id = dev->pdata->chip_id;
-
dev->reset_gpio = devm_gpiod_get_optional(dev->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(dev->reset_gpio))
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index d1b2db8e6..fe1525ffe 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -14,6 +14,7 @@
#include
#include
#include
+#include
#define KSZ_MAX_NUM_PORTS 8
@@ -162,24 +163,6 @@ enum ksz_model {
LAN9374,
};
-enum ksz_chip_id {
- KSZ8563_CHIP_ID = 0x8563,
- KSZ8795_CHIP_ID = 0x8795,
- KSZ8794_CHIP_ID = 0x8794,
- KSZ8765_CHIP_ID = 0x8765,
- KSZ8830_CHIP_ID = 0x8830,
- KSZ9477_CHIP_ID = 0x00947700,
- KSZ9896_CHIP_ID = 0x00989600,
- KSZ9897_CHIP_ID = 0x00989700,
- KSZ9893_CHIP_ID = 0x00989300,
- KSZ9567_CHIP_ID = 0x00956700,
- LAN9370_CHIP_ID = 0x00937000,
- LAN9371_CHIP_ID = 0x00937100,
- LAN9372_CHIP_ID = 0x00937200,
- LAN9373_CHIP_ID = 0x00937300,
- LAN9374_CHIP_ID = 0x00937400,
-};
-
enum ksz_regs {
REG_IND_CTRL_0,
REG_IND_DATA_8,
diff --git a/include/linux/platform_data/microchip-ksz.h b/include/linux/platform_data/microchip-ksz.h
index ea1cc6d82..3f24a7a44 100644
--- a/include/linux/platform_data/microchip-ksz.h
+++ b/include/linux/platform_data/microchip-ksz.h
@@ -20,10 +20,30 @@
#define __MICROCHIP_KSZ_H
#include
+#include
+
+enum ksz_chip_id {
+ KSZ8563_CHIP_ID = 0x8563,
+ KSZ8795_CHIP_ID = 0x8795,
+ KSZ8794_CHIP_ID = 0x8794,
+ KSZ8765_CHIP_ID = 0x8765,
+ KSZ8830_CHIP_ID = 0x8830,
+ KSZ9477_CHIP_ID = 0x00947700,
+ KSZ9896_CHIP_ID = 0x00989600,
+ KSZ9897_CHIP_ID = 0x00989700,
+ KSZ9893_CHIP_ID = 0x00989300,
+ KSZ9567_CHIP_ID = 0x00956700,
+ LAN9370_CHIP_ID = 0x00937000,
+ LAN9371_CHIP_ID = 0x00937100,
+ LAN9372_CHIP_ID = 0x00937200,
+ LAN9373_CHIP_ID = 0x00937300,
+ LAN9374_CHIP_ID = 0x00937400,
+};
struct ksz_platform_data {
+ /* Must be first such that dsa_register_switch() can access it */
+ struct dsa_chip_data cd;
u32 chip_id;
- u16 enabled_ports;
};
#endif
--
2.39.2