Re: [PATCH] pinctrl: at91-pio4: add support for fewer lines on last PIO bank

From: Ludovic Desroches
Date: Mon Nov 16 2020 - 01:15:56 EST


On Fri, Nov 13, 2020 at 03:24:29PM +0200, Eugen Hristev wrote:
> Some products, like sama7g5, do not have a full last bank of PIO lines.
> In this case for example, sama7g5 only has 8 lines for the PE bank.
> PA0-31, PB0-31, PC0-31, PD0-31, PE0-7, in total 136 lines.
> To cope with this situation, added a data attribute that is product dependent,
> to specify the number of lines of the last bank.
> In case this number is different from the macro ATMEL_PIO_NPINS_PER_BANK,
> adjust the total number of lines accordingly.
> This will avoid advertising 160 lines instead of the actual 136, as this
> product supports, and to avoid reading/writing to invalid register addresses.
>
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>

Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>

Thanks.

> ---
> drivers/pinctrl/pinctrl-at91-pio4.c | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
> index 578b387100d9..d267367d94b9 100644
> --- a/drivers/pinctrl/pinctrl-at91-pio4.c
> +++ b/drivers/pinctrl/pinctrl-at91-pio4.c
> @@ -71,8 +71,15 @@
> /* Custom pinconf parameters */
> #define ATMEL_PIN_CONFIG_DRIVE_STRENGTH (PIN_CONFIG_END + 1)
>
> +/**
> + * struct atmel_pioctrl_data - Atmel PIO controller (pinmux + gpio) data struct
> + * @nbanks: number of PIO banks
> + * @last_bank_count: number of lines in the last bank (can be less than
> + * the rest of the banks).
> + */
> struct atmel_pioctrl_data {
> unsigned nbanks;
> + unsigned last_bank_count;
> };
>
> struct atmel_group {
> @@ -980,11 +987,13 @@ static const struct dev_pm_ops atmel_pctrl_pm_ops = {
> * We can have up to 16 banks.
> */
> static const struct atmel_pioctrl_data atmel_sama5d2_pioctrl_data = {
> - .nbanks = 4,
> + .nbanks = 4,
> + .last_bank_count = ATMEL_PIO_NPINS_PER_BANK,
> };
>
> static const struct atmel_pioctrl_data microchip_sama7g5_pioctrl_data = {
> - .nbanks = 5,
> + .nbanks = 5,
> + .last_bank_count = 8, /* sama7g5 has only PE0 to PE7 */
> };
>
> static const struct of_device_id atmel_pctrl_of_match[] = {
> @@ -1025,6 +1034,11 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
> atmel_pioctrl_data = match->data;
> atmel_pioctrl->nbanks = atmel_pioctrl_data->nbanks;
> atmel_pioctrl->npins = atmel_pioctrl->nbanks * ATMEL_PIO_NPINS_PER_BANK;
> + /* if last bank has limited number of pins, adjust accordingly */
> + if (atmel_pioctrl_data->last_bank_count != ATMEL_PIO_NPINS_PER_BANK) {
> + atmel_pioctrl->npins -= ATMEL_PIO_NPINS_PER_BANK;
> + atmel_pioctrl->npins += atmel_pioctrl_data->last_bank_count;
> + }
>
> atmel_pioctrl->reg_base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(atmel_pioctrl->reg_base))
> --
> 2.25.1
>