From 3bc05faf37876f99e2a7baffa9c66fdcfb11d1f7 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 5 Dec 2023 17:42:30 +0100 Subject: 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. Link: https://lore.kernel.org/netdev/20231204154315.3906267-1-dd@embedd.com/ Signed-off-by: Vladimir Oltean Signed-off-by: Daniel Danzberger Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/dsa/microchip/ksz_common.c | 21 +++++++++++++-------- include/linux/platform_data/microchip-ksz.h | 4 +++- 2 files changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 9545aed905f5..db1bbcf3a5f2 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -1673,15 +1673,23 @@ 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; } @@ -4156,9 +4164,6 @@ 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/include/linux/platform_data/microchip-ksz.h b/include/linux/platform_data/microchip-ksz.h index ea1cc6d829e9..6480bf4af0fb 100644 --- a/include/linux/platform_data/microchip-ksz.h +++ b/include/linux/platform_data/microchip-ksz.h @@ -20,10 +20,12 @@ #define __MICROCHIP_KSZ_H #include +#include 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 -- cgit