Hi, Philipp,
On 09.05.2025 13:51, Philipp Zabel wrote:
> Hi Claudiu,
>
> On Mi, 2025-04-30 at 13:32 +0300, Claudiu wrote:
>> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>>
>> The Renesas RZ/G3S features a PCIe IP that complies with the PCI Express
>> Base Specification 4.0 and supports speeds of up to 5 GT/s. It functions
>> only as a root complex, with a single-lane (x1) configuration. The
>> controller includes Type 1 configuration registers, as well as IP
>> specific registers (called AXI registers) required for various adjustments.
>>
>> Other Renesas RZ SoCs (e.g., RZ/G3E, RZ/V2H) share the same AXI registers
>> but have both Root Complex and Endpoint capabilities. As a result, the PCIe
>> host driver can be reused for these variants with minimal adjustments.
>>
>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>> ---
>> MAINTAINERS | 8 +
>> drivers/pci/controller/Kconfig | 7 +
>> drivers/pci/controller/Makefile | 1 +
>> drivers/pci/controller/pcie-rzg3s-host.c | 1561 ++++++++++++++++++++++
>> 4 files changed, 1577 insertions(+)
>> create mode 100644 drivers/pci/controller/pcie-rzg3s-host.c
>>
> [...]
>> diff --git a/drivers/pci/controller/pcie-rzg3s-host.c b/drivers/pci/controller/pcie-rzg3s-host.c
>> new file mode 100644
>> index 000000000000..c3bce0acd57e
>> --- /dev/null
>> +++ b/drivers/pci/controller/pcie-rzg3s-host.c
>> @@ -0,0 +1,1561 @@
> [...]
>> +static int rzg3s_pcie_resets_bulk_set(int (*action)(int num, struct reset_control_bulk_data *rstcs),
>> + struct reset_control **resets, u8 num_resets)
>> +{
>> + struct reset_control_bulk_data *data __free(kfree) =
>> + kcalloc(num_resets, sizeof(*data), GFP_KERNEL);
>> +
>> + if (!data)
>> + return -ENOMEM;
>> +
>> + for (u8 i = 0; i < num_resets; i++)
>> + data[i].rstc = resets[i];
>> +
>> + return action(num_resets, data);
>> +}
>
> What is the purpose of this? Can't you just store struct
> reset_control_bulk_data in struct rzg3s_pcie_host and call
> reset_control_bulk_assert/deassert() directly?
Yes, I can. I was trying to avoid storing also the reset_control_bulk_data
in struct rzg3s_pcie_host since all that is needed can be retrieved from
the already parsed in probe cfg_resets and power_resets.
>
>> +static int
>> +rzg3s_pcie_resets_init(struct device *dev, struct reset_control ***resets,
>> + struct reset_control *(*action)(struct device *dev, const char *id),
>> + const char * const *reset_names, u8 num_resets)
>> +{
>> + *resets = devm_kcalloc(dev, num_resets, sizeof(struct reset_control *), GFP_KERNEL);
>> + if (!*resets)
>> + return -ENOMEM;
>> +
>> + for (u8 i = 0; i < num_resets; i++) {
>> + (*resets)[i] = action(dev, reset_names[i]);
>> + if (IS_ERR((*resets)[i]))
>> + return PTR_ERR((*resets)[i]);
>> + }
>> +
>> + return 0;
>> +}
>
> Why not use devm_reset_control_bulk_get_exclusive() directly?
I wasn't able to find a bulk_get_exclusive_deasserted() kind of API.
This IP needs particular sequence for configuration. First, after power on,
the following resets need to be de-asserted:
const char * const power_resets[] = {
"aresetn", "rst_cfg_b", "rst_load_b",
};
then, after proper values are written into the configuration registers, the
rest of the resets need to be de-asserted:
const char * const cfg_resets[] = {
"rst_b", "rst_ps_b", "rst_gp_b", "rst_rsm_b",
};
So I was trying to get and de-assert the power_resets in probe and just get
the cfg_resets in the 1st step of the initialization, and later to
de-assert the cfg_resets as well.
Now, after you pointed it out, maybe you are proposing to just
get_exclusive everything in one shot and then to de-assert what is needed
at proper moments with generic reset control APIs?
Thank you for your review,
Claudiu
