Re: [PATCH 1/2] mfd: ti_am335x_tscadc: Provide unique name for child mfd cells

From: Vignesh R
Date: Wed Nov 28 2018 - 06:43:26 EST




On 28/11/18 4:33 PM, Lee Jones wrote:
> On Wed, 28 Nov 2018, Vignesh R wrote:
>
>> Hi,
>>
>> On 28/11/18 2:37 PM, Lee Jones wrote:
>>> On Mon, 19 Nov 2018, Vignesh R wrote:
>>>
>>>> Provide unique names for child mfd cells, this is required in order to
>>>> support registering of multiple instances of same ti_am335x_tscadc IP.
>>>
>>> I don't think it is. What is the error you are receiving?
>>
>> W/o this patch I get:
>>
>> [ 2.296839] sysfs: cannot create duplicate filename '/bus/platform/devices/TI-am335x-adc'
>> [ 2.305085] CPU: 0 PID: 31 Comm: kworker/0:1 Not tainted 4.20.0-rc3-next-20181123-00018-g
>> 7791ce8f123f-dirty #182
>> [ 2.315254] Hardware name: Texas Instruments AM654 Base Board (DT)
>> [ 2.321447] Workqueue: events deferred_probe_work_func
>> [ 2.326585] Call trace:
>> [ 2.329036] dump_backtrace+0x0/0x1c0
>> [ 2.332699] show_stack+0x14/0x20
>> [ 2.336017] dump_stack+0x9c/0xbc
>> [ 2.339333] sysfs_warn_dup+0x60/0x78
>> [ 2.342995] sysfs_do_create_link_sd.isra.0+0xdc/0xe8
>> [ 2.348042] sysfs_create_link+0x20/0x40
>> [ 2.351963] bus_add_device+0x68/0x130
>> [ 2.355711] device_add+0x398/0x618
>> [ 2.359199] platform_device_add+0x120/0x290
>> [ 2.363469] mfd_add_device+0x23c/0x2e8
>> [ 2.367302] mfd_add_devices+0xb4/0x158
>> [ 2.371136] ti_tscadc_probe+0x35c/0x4c8
>> [ 2.375056] platform_drv_probe+0x50/0xa0
>> [ 2.379062] really_probe+0x204/0x2a8
>> [ 2.382722] driver_probe_device+0x58/0x100
>> [ 2.386903] __device_attach_driver+0x98/0xf0
>> [ 2.391258] bus_for_each_drv+0x64/0xc8
>> [ 2.395091] __device_attach+0xd8/0x138
>> [ 2.398923] device_initial_probe+0x10/0x18
>> [ 2.403103] bus_probe_device+0x90/0x98
>> [ 2.406938] deferred_probe_work_func+0x74/0xb0
>> [ 2.411470] process_one_work+0x1e0/0x330
>> [ 2.415478] worker_thread+0x238/0x460
>> [ 2.419225] kthread+0x128/0x130
>> [ 2.422452] ret_from_fork+0x10/0x1c
>> [ 2.426195] ti_am3359-tscadc: probe of 40210000.tscadc failed with error -1
>
> That's because of the way the cells are being registered:
>
> err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
> tscadc->used_cells, NULL, 0, NULL);
>
> The cells are not numbered (tscadc->cells->id is always 0) and you are
> forcing the use of the platform ID from the parent platform device
> (with pdev->id here). Instead you should s/pdev->id/PLATFORM_DEVID_AUTO/
> or number the cells manually. I suggest the former.
>

Using PLATFORM_DEVID_AUTO works fine. I will post v2 with this change.
Thanks for the suggestion!

Regards
Vignesh

>>>> Signed-off-by: Vignesh R <vigneshr@xxxxxx>
>>>> ---
>>>> drivers/mfd/ti_am335x_tscadc.c | 6 ++++--
>>>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
>>>> index c2d47d78705b..ee08af34f81d 100644
>>>> --- a/drivers/mfd/ti_am335x_tscadc.c
>>>> +++ b/drivers/mfd/ti_am335x_tscadc.c
>>>> @@ -248,7 +248,8 @@ static int ti_tscadc_probe(struct platform_device *pdev)
>>>> if (tsc_wires > 0) {
>>>> tscadc->tsc_cell = tscadc->used_cells;
>>>> cell = &tscadc->cells[tscadc->used_cells++];
>>>> - cell->name = "TI-am335x-tsc";
>>>> + cell->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s:%s",
>>>> + dev_name(&pdev->dev), "tsc");
>>>> cell->of_compatible = "ti,am3359-tsc";
>>>> cell->platform_data = &tscadc;
>>>> cell->pdata_size = sizeof(tscadc);
>>>> @@ -258,7 +259,8 @@ static int ti_tscadc_probe(struct platform_device *pdev)
>>>> if (adc_channels > 0) {
>>>> tscadc->adc_cell = tscadc->used_cells;
>>>> cell = &tscadc->cells[tscadc->used_cells++];
>>>> - cell->name = "TI-am335x-adc";
>>>> + cell->name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s:%s",
>>>> + dev_name(&pdev->dev), "adc");
>>>> cell->of_compatible = "ti,am3359-adc";
>>>> cell->platform_data = &tscadc;
>>>> cell->pdata_size = sizeof(tscadc);
>>>
>>
>

--
Regards
Vignesh