[PATCH RFT] pinctrl: sunxi: Fix A733 withstand programming

[Andre Przywara <andre.przywara@arm.com>]

On top of the other pinctrl changes that the Allwinner A733 introduced, it
also uses a different layout for the GPIO_POW_MOD_SEL register, to set up
the GPIO input threshold voltage for each port. For no apparent reason,
it uses now 2 bits per bank, though effectively just always setting the
higher bit to 1 is all that's needed to make it work.

Add a new BIAS_VOLTAGE_PIO_POW_SEL variant, that behaves similar to the
existing one, but uses the 2-bit encoding. Use that variant for the A733
pinctrl driver.

Fixes: 0535bfbfa97b ("pinctrl: sunxi: add support for the Allwinner A733")
Reported-by: Vinicius Pedrosa <vinicius.eduardo.pedrosa@gmail.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
Hi,

this goes on top of LinusW's pinctrl/for-next branch, which contains
both the A523 withstand fix and the A733 pinctrl bits.
Did not test on hardware, please have a look!

Cheers,
Andre

 drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c |  2 +-
 drivers/pinctrl/sunxi/pinctrl-sunxi.c       | 12 +++++++++---
 drivers/pinctrl/sunxi/pinctrl-sunxi.h       |  4 ++++
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c b/drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c
index ca82f08a3a65b..dcc2254e4089f 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sun60i-a733.c
@@ -24,7 +24,7 @@ static const u8 a733_irq_bank_muxes[SUNXI_PINCTRL_MAX_BANKS] =
 static struct sunxi_pinctrl_desc a733_pinctrl_data = {
 	.irq_banks = 10,
 	.irq_read_needs_mux = true,
-	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_SEL,
+	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_SEL_2BIT,
 };
 
 static int a733_pinctrl_probe(struct platform_device *pdev)
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 3ee5012463da3..7f4ce73bdc670 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -783,6 +783,7 @@ static int sunxi_pinctrl_set_io_bias_cfg(struct sunxi_pinctrl *pctl,
 		raw_spin_unlock_irqrestore(&pctl->lock, flags);
 
 		fallthrough;
+	case BIAS_VOLTAGE_PIO_POW_MODE_SEL_2BIT:
 	case BIAS_VOLTAGE_PIO_POW_MODE_SEL:
 		val = uV <= 1800000 ? 1 : 0;
 		if (inverted)
@@ -790,9 +791,14 @@ static int sunxi_pinctrl_set_io_bias_cfg(struct sunxi_pinctrl *pctl,
 
 		raw_spin_lock_irqsave(&pctl->lock, flags);
 		reg = readl(pctl->membase + pctl->pow_mod_sel_offset);
-		reg &= ~(1 << bank);
-		writel(reg | val << bank,
-		       pctl->membase + pctl->pow_mod_sel_offset);
+		if (pctl->desc->io_bias_cfg_variant == BIAS_VOLTAGE_PIO_POW_MODE_SEL_2BIT) {
+			reg &= ~(3U << (bank * 2));
+			reg |= (val | 0x2) << (bank * 2);
+		} else {
+			reg &= ~BIT(bank);
+			reg |= val << bank;
+		}
+		writel(reg, pctl->membase + pctl->pow_mod_sel_offset);
 		raw_spin_unlock_irqrestore(&pctl->lock, flags);
 		return 0;
 	default:
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.h b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
index 7c2f29e75519a..0945890a921b6 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
@@ -122,6 +122,10 @@ enum sunxi_desc_bias_voltage {
 	 * register, as seen on H6 SoC, for example.
 	 */
 	BIAS_VOLTAGE_PIO_POW_MODE_SEL,
+	/*
+	 * Same as above, but using a 2-bits-per-bank encoding.
+	 */
+	BIAS_VOLTAGE_PIO_POW_MODE_SEL_2BIT,
 	/*
 	 * Bias voltage is set through PIO_POW_MOD_SEL_REG
 	 * and PIO_POW_MOD_CTL_REG register, as seen on
-- 
2.43.0