On 23/10/2024 13:00, Daniel Machon wrote: > Hi Krzysztof, > >>> Add compatible strings for the twelve lan969x SKU's (Stock Keeping Unit) >>> that we support, and verify that the devicetree target is supported by >>> the chip target. >>> >>> Each SKU supports different bandwidths and features (see [1] for >>> details). We want to be able to run a SKU with a lower bandwidth and/or >>> feature set, than what is supported by the actual chip. In order to >>> accomplish this we: >>> >>> - add new field sparx5->target_dt that reflects the target from the >>> devicetree (compatible string). >>> >>> - compare the devicetree target with the actual chip target. If the >>> bandwidth and features provided by the devicetree target is >>> supported by the chip, we approve - otherwise reject. >>> >>> - set the core clock and features based on the devicetree target >>> >>> [1] https://www.microchip.com/en-us/product/lan9698 >>> >>> Reviewed-by: Steen Hegelund <Steen.Hegelund@xxxxxxxxxxxxx> >>> Signed-off-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx> >>> --- >>> drivers/net/ethernet/microchip/sparx5/Makefile | 1 + >>> .../net/ethernet/microchip/sparx5/sparx5_main.c | 194 ++++++++++++++++++++- >>> .../net/ethernet/microchip/sparx5/sparx5_main.h | 1 + >>> 3 files changed, 193 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/net/ethernet/microchip/sparx5/Makefile b/drivers/net/ethernet/microchip/sparx5/Makefile >>> index 3435ca86dd70..8fe302415563 100644 >>> --- a/drivers/net/ethernet/microchip/sparx5/Makefile >>> +++ b/drivers/net/ethernet/microchip/sparx5/Makefile >>> @@ -19,3 +19,4 @@ sparx5-switch-$(CONFIG_DEBUG_FS) += sparx5_vcap_debugfs.o >>> # Provide include files >>> ccflags-y += -I$(srctree)/drivers/net/ethernet/microchip/vcap >>> ccflags-y += -I$(srctree)/drivers/net/ethernet/microchip/fdma >>> +ccflags-y += -I$(srctree)/drivers/net/ethernet/microchip/lan969x >>> diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c >>> index 5c986c373b3e..edbe639d98c5 100644 >>> --- a/drivers/net/ethernet/microchip/sparx5/sparx5_main.c >>> +++ b/drivers/net/ethernet/microchip/sparx5/sparx5_main.c >>> @@ -24,6 +24,8 @@ >>> #include <linux/types.h> >>> #include <linux/reset.h> >>> >>> +#include "lan969x.h" /* lan969x_desc */ >>> + >>> #include "sparx5_main_regs.h" >>> #include "sparx5_main.h" >>> #include "sparx5_port.h" >>> @@ -227,6 +229,168 @@ bool is_sparx5(struct sparx5 *sparx5) >>> } >>> } >>> >>> +/* Set the devicetree target based on the compatible string */ >>> +static int sparx5_set_target_dt(struct sparx5 *sparx5) >>> +{ >>> + struct device_node *node = sparx5->pdev->dev.of_node; >>> + >>> + if (is_sparx5(sparx5)) >>> + /* For Sparx5 the devicetree target is always the chip target */ >>> + sparx5->target_dt = sparx5->target_ct; >>> + else if (of_device_is_compatible(node, "microchip,lan9691-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9691VAO; >>> + else if (of_device_is_compatible(node, "microchip,lan9692-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9692VAO; >>> + else if (of_device_is_compatible(node, "microchip,lan9693-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9693VAO; >>> + else if (of_device_is_compatible(node, "microchip,lan9694-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9694; >>> + else if (of_device_is_compatible(node, "microchip,lan9695-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9694TSN; >>> + else if (of_device_is_compatible(node, "microchip,lan9696-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9696; >>> + else if (of_device_is_compatible(node, "microchip,lan9697-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9696TSN; >>> + else if (of_device_is_compatible(node, "microchip,lan9698-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9698; >>> + else if (of_device_is_compatible(node, "microchip,lan9699-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9698TSN; >>> + else if (of_device_is_compatible(node, "microchip,lan969a-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9694RED; >>> + else if (of_device_is_compatible(node, "microchip,lan969b-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9696RED; >>> + else if (of_device_is_compatible(node, "microchip,lan969c-switch")) >>> + sparx5->target_dt = SPX5_TARGET_CT_LAN9698RED; >>> + else >>> + return -EINVAL; >>> + >>> + return 0; >>> +} >>> + >>> +/* Compare the devicetree target with the chip target. >>> + * Make sure the chip target supports the features and bandwidth requested >>> + * from the devicetree target. >>> + */ >>> +static int sparx5_verify_target(struct sparx5 *sparx5) >>> +{ >>> + switch (sparx5->target_dt) { >>> + case SPX5_TARGET_CT_7546: >>> + case SPX5_TARGET_CT_7549: >>> + case SPX5_TARGET_CT_7552: >>> + case SPX5_TARGET_CT_7556: >>> + case SPX5_TARGET_CT_7558: >>> + case SPX5_TARGET_CT_7546TSN: >>> + case SPX5_TARGET_CT_7549TSN: >>> + case SPX5_TARGET_CT_7552TSN: >>> + case SPX5_TARGET_CT_7556TSN: >>> + case SPX5_TARGET_CT_7558TSN: >>> + return 0; >> >> All this is weird. Why would you verify? You were matched, it cannot be >> mis-matching. > > We are verifying that the match (target/compatible string) from the > device tree is supported by the chip. Maybe I wasn't too clear about the > intend in v1. > > Each target supports different bandwidths and features. If you have a > lan9698 chip, it must, obviously, be possible to run it as a lan9698 > target. However, some targets can be run on chip targets other than > themselves, given that the chip supports the bandwidth and features of > the provided target. In contrary, trying to run as a target with a > feature not supported by the chip, or a bandwidth higher than what the > chip supports, should be rejected. But you are not supposed to compare DT with what you auto-detected. Detect your hardware, test if it is supported and then bail out. None of above explains the code. > > Without this logic, the chip id is read and a target is determined. That > means on a lan9698 chip you will always match the lan9698 target. That's not the job of kernel. > > With the new logic, it is possible to run as a different target than > what is read from the chip id, given that the target you are trying to > run as, is supported by the chip. So just run on different target. > >> >>> + case SPX5_TARGET_CT_LAN9698RED: >>> + if (sparx5->target_ct == SPX5_TARGET_CT_LAN9698RED) >> >> What is "ct"? sorry, all this code is a big no. > > In this case we were matched as a SPX5_TARGET_CT_LAN9698RED target. We > are verifying that the chip target (target_ct, which is read from the > chip) supports the target we were matched as. > >> Krzysztof >> > > This is a feature that we would like, as it gives the flexibility of > running different targets on the same chip. Now if this is something > that cannot be accepted, I will have to ditch this part. I have no clue what the "target" is but so far it looks like you try to validate DT against detected device. That's not how it should work. Best regards, Krzysztof
