Re: [RFC PATCH 4/4] pinctrl: renesas: pinctrl-rzg2l: Add support to get/set drive-strength and output-impedance
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2021-10-07 17:23:48
Also in:
linux-gpio, linux-renesas-soc, lkml
Hi Prabhakar, On Thu, Sep 30, 2021 at 2:17 PM Lad Prabhakar [off-list ref] wrote:
Add support to get/set drive-strength and output-impedance of the pins. Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Thanks for your patch!
quoted hunk ↗ jump to hunk
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c@@ -47,6 +47,7 @@ #define PIN_CFG_FILONOFF BIT(9) #define PIN_CFG_FILNUM BIT(10) #define PIN_CFG_FILCLKSEL BIT(11) +#define PIN_CFG_GROUP_B BIT(12)
Perhaps it would be easier to have separate PIN_CFG_IOLH_A and PIN_CFG_IOLH_B flags, instead of a PIN_CFG_IOLH flag and a PIN_CFG_GROUP_B modifier flag?
#define RZG2L_MPXED_PIN_FUNCS (PIN_CFG_IOLH | \
PIN_CFG_SR | \quoted hunk ↗ jump to hunk
@@ -484,6 +513,38 @@ static int rzg2l_pinctrl_pinconf_get(struct pinctrl_dev *pctldev, break; } + case PIN_CONFIG_OUTPUT_IMPEDANCE: + case PIN_CONFIG_DRIVE_STRENGTH: { + unsigned int mA[4] = { 2, 4, 8, 12 }; + unsigned int oi[4] = { 100, 66, 50, 33 };
static const
+
+ if (param == PIN_CONFIG_DRIVE_STRENGTH) {
+ if (!(cfg & PIN_CFG_IOLH) || groupb_pin)
+ return -EINVAL;
+ } else {
+ if (!(cfg & PIN_CFG_IOLH) || !groupb_pin)
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&pctrl->lock, flags);
+
+ /* handle _L/_H for 32-bit register read/write */
+ addr = pctrl->base + IOLH(port);
+ if (bit >= 4) {
+ bit -= 4;
+ addr += 4;
+ }
+
+ reg = readl(addr) & (IOLH_MASK << (bit * 8));
+ reg = reg >> (bit * 8);
+ if (param == PIN_CONFIG_DRIVE_STRENGTH)
+ arg = mA[reg];
+ else
+ arg = oi[reg];
+ spin_unlock_irqrestore(&pctrl->lock, flags);I think you've reached the point where it starts to make sense to have helper functions to read and modify these sub-register fields that may be located into the current or next register. And after that, you can split it in two smaller separate cases for drive strength and output impedance.
+ break;
+ }
+
default:
return -ENOTSUPP;
}
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds