Re: [PATCH V3 06/11] i3c: mipi-i3c-hci-pci: Assign unique device names and IDs for Intel LPSS I3C

Adrian Hunter
2025-12-16T17:14:49Z

On 16/12/2025 19:08, Frank Li wrote:
> On Tue, Dec 16, 2025 at 06:56:37PM +0200, Adrian Hunter wrote:
>> Simplify the code and ensure names and IDs align with device documentation.
>> Use explicit device names and IDs for Intel LPSS I3C controllers instead of
>> dynamically allocated values.
>>
>> Add "intel-lpss-i3c" to the platform_device_id table in the mipi-i3c-hci
>> driver and use the same name for Intel I3C controllers in the
>> mipi_i3c_hci_pci driver. Assign hard-coded IDs to reflect the hardware
>> layout.
>>
>> Intel SoCs include two I3C PCI devices in the Low Power Subsystem (LPSS),
>> each supporting up to two I3C buses. The second PCI device is assigned ID 2
>> (not 1) to match this topology. Additional IDs will be introduced when
>> Multi-Bus Instance support is implemented.
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>
>>
>> Change in V3:
>>
>> New patch
>>
>>
>> drivers/i3c/master/mipi-i3c-hci/core.c | 7 +++
>> .../master/mipi-i3c-hci/mipi-i3c-hci-pci.c | 43 ++++++++++---------
>> 2 files changed, 30 insertions(+), 20 deletions(-)
>>
>> diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c
>> index 07fb91a12593..3d6544a64188 100644
>> --- a/drivers/i3c/master/mipi-i3c-hci/core.c
>> +++ b/drivers/i3c/master/mipi-i3c-hci/core.c
>> @@ -790,9 +790,16 @@ static const struct acpi_device_id i3c_hci_acpi_match[] = {
>> };
>> MODULE_DEVICE_TABLE(acpi, i3c_hci_acpi_match);
>>
>> +static const struct platform_device_id i3c_hci_driver_ids[] = {
>> + { .name = "intel-lpss-i3c" },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(platform, i3c_hci_driver_ids);
>> +
>> static struct platform_driver i3c_hci_driver = {
>> .probe = i3c_hci_probe,
>> .remove = i3c_hci_remove,
>> + .id_table = i3c_hci_driver_ids,
>> .driver = {
>> .name = "mipi-i3c-hci",
>> .of_match_table = of_match_ptr(i3c_hci_of_match),
>> diff --git a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>> index 0fd3587671e1..3b319fbf18ce 100644
>> --- a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>> +++ b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>> @@ -27,10 +27,10 @@ struct mipi_i3c_hci_pci {
>> struct mipi_i3c_hci_pci_info {
>> int (*init)(struct mipi_i3c_hci_pci *hci);
>> void (*exit)(struct mipi_i3c_hci_pci *hci);
>> + const char *name;
>> + int id;
>> };
>>
>> -static DEFINE_IDA(mipi_i3c_hci_pci_ida);
>> -
>> #define INTEL_PRIV_OFFSET 0x2b0
>> #define INTEL_PRIV_SIZE 0x28
>> #define INTEL_RESETS 0x04
>> @@ -179,9 +179,18 @@ static void intel_i3c_exit(struct mipi_i3c_hci_pci *hci)
>> intel_ltr_hide(&hci->pci->dev);
>> }
>>
>> -static const struct mipi_i3c_hci_pci_info intel_info = {
>> +static const struct mipi_i3c_hci_pci_info intel_1_info = {
>> .init = intel_i3c_init,
>> .exit = intel_i3c_exit,
>> + .name = "intel-lpss-i3c",
>> + .id = 0,
>> +};
>> +
>> +static const struct mipi_i3c_hci_pci_info intel_2_info = {
>> + .init = intel_i3c_init,
>> + .exit = intel_i3c_exit,
>> + .name = "intel-lpss-i3c",
>> + .id = 2,
>> };
>>
>> static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>> @@ -189,7 +198,7 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>> {
>> struct mipi_i3c_hci_pci *hci;
>> struct resource res[2];
>> - int dev_id, ret;
>> + int ret;
>>
>> hci = devm_kzalloc(&pci->dev, sizeof(*hci), GFP_KERNEL);
>> if (!hci)
>> @@ -217,11 +226,9 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>> res[1].start = pci_irq_vector(hci->pci, 0);
>> res[1].end = res[1].start;
>>
>> - dev_id = ida_alloc(&mipi_i3c_hci_pci_ida, GFP_KERNEL);
>> - if (dev_id < 0)
>> - return dev_id;
>> + hci->info = (const struct mipi_i3c_hci_pci_info *)id->driver_data;
>>
>> - hci->pdev = platform_device_alloc("mipi-i3c-hci", dev_id);
>> + hci->pdev = platform_device_alloc(hci->info->name, hci->info->id);
>> if (!hci->pdev)
>> return -ENOMEM;
>>
>> @@ -232,7 +239,6 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>> if (ret)
>> goto err;
>>
>> - hci->info = (const struct mipi_i3c_hci_pci_info *)id->driver_data;
>> if (hci->info->init) {
>> ret = hci->info->init(hci);
>> if (ret)
>> @@ -252,7 +258,6 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>> hci->info->exit(hci);
>> err:
>> platform_device_put(hci->pdev);
>> - ida_free(&mipi_i3c_hci_pci_ida, dev_id);
>> return ret;
>> }
>>
>> @@ -260,28 +265,26 @@ static void mipi_i3c_hci_pci_remove(struct pci_dev *pci)
>> {
>> struct mipi_i3c_hci_pci *hci = pci_get_drvdata(pci);
>> struct platform_device *pdev = hci->pdev;
>> - int dev_id = pdev->id;
>>
>> if (hci->info->exit)
>> hci->info->exit(hci);
>>
>> platform_device_unregister(pdev);
>> - ida_free(&mipi_i3c_hci_pci_ida, dev_id);
>> }
>>
>> static const struct pci_device_id mipi_i3c_hci_pci_devices[] = {
>> /* Wildcat Lake-U */
>> - { PCI_VDEVICE(INTEL, 0x4d7c), (kernel_ulong_t)&intel_info},
>> - { PCI_VDEVICE(INTEL, 0x4d6f), (kernel_ulong_t)&intel_info},
>> + { PCI_VDEVICE(INTEL, 0x4d7c), (kernel_ulong_t)&intel_1_info},
>
> If there there are two 0x4d7c pcie cards in system, id will be the same.
> Is it okay?

These are not cards. These PCI device IDs are unique to each device
in the SoC, so duplicate IDs would never happen.

>
> Frank
>
>> + { PCI_VDEVICE(INTEL, 0x4d6f), (kernel_ulong_t)&intel_2_info},
>> /* Panther Lake-H */
>> - { PCI_VDEVICE(INTEL, 0xe37c), (kernel_ulong_t)&intel_info},
>> - { PCI_VDEVICE(INTEL, 0xe36f), (kernel_ulong_t)&intel_info},
>> + { PCI_VDEVICE(INTEL, 0xe37c), (kernel_ulong_t)&intel_1_info},
>> + { PCI_VDEVICE(INTEL, 0xe36f), (kernel_ulong_t)&intel_2_info},
>> /* Panther Lake-P */
>> - { PCI_VDEVICE(INTEL, 0xe47c), (kernel_ulong_t)&intel_info},
>> - { PCI_VDEVICE(INTEL, 0xe46f), (kernel_ulong_t)&intel_info},
>> + { PCI_VDEVICE(INTEL, 0xe47c), (kernel_ulong_t)&intel_1_info},
>> + { PCI_VDEVICE(INTEL, 0xe46f), (kernel_ulong_t)&intel_2_info},
>> /* Nova Lake-S */
>> - { PCI_VDEVICE(INTEL, 0x6e2c), (kernel_ulong_t)&intel_info},
>> - { PCI_VDEVICE(INTEL, 0x6e2d), (kernel_ulong_t)&intel_info},
>> + { PCI_VDEVICE(INTEL, 0x6e2c), (kernel_ulong_t)&intel_1_info},
>> + { PCI_VDEVICE(INTEL, 0x6e2d), (kernel_ulong_t)&intel_2_info},
>> { },
>> };
>> MODULE_DEVICE_TABLE(pci, mipi_i3c_hci_pci_devices);
>> --
>> 2.51.0
>>
>>
>> --
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