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From:   Samuel Holland <samuel@sholland.org>
To:     Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Linus Walleij <linus.walleij@linaro.org>
Cc:     Samuel Holland <samuel@sholland.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Maxime Ripard <mripard@kernel.org>, Ondrej Jirman <x@xff.cz>,
        Rob Herring <robh+dt@kernel.org>, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev
Subject: [PATCH 3/6] pinctrl: sunxi: Support the 2.5V I/O bias mode
Date:   Sat, 25 Jun 2022 21:11:44 -0500
Message-Id: <20220626021148.56740-4-samuel@sholland.org>
In-Reply-To: <20220626021148.56740-1-samuel@sholland.org>
References: <20220626021148.56740-1-samuel@sholland.org>
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H616 and newer SoCs feature a 2.5V I/O bias mode in addition to the
1.8V and 3.3V modes. This mode is entered by selecting the 3.3V level
and disabling the "withstand function".

H616 supports this capability on its main PIO only. A100 supports this
capability on both its PIO and R-PIO.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

 drivers/pinctrl/sunxi/pinctrl-sun50i-a100-r.c |  1 +
 drivers/pinctrl/sunxi/pinctrl-sun50i-a100.c   |  2 +-
 drivers/pinctrl/sunxi/pinctrl-sun50i-h616.c   |  2 +-
 drivers/pinctrl/sunxi/pinctrl-sunxi.c         | 10 ++++++++++
 drivers/pinctrl/sunxi/pinctrl-sunxi.h         |  7 +++++++
 5 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/sunxi/pinctrl-sun50i-a100-r.c b/drivers/pinctrl/sunxi/pinctrl-sun50i-a100-r.c
index 21054fcacd34..afc1f5df7545 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sun50i-a100-r.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sun50i-a100-r.c
@@ -82,6 +82,7 @@ static const struct sunxi_pinctrl_desc a100_r_pinctrl_data = {
 	.npins = ARRAY_SIZE(a100_r_pins),
 	.pin_base = PL_BASE,
 	.irq_banks = 1,
+	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_CTL,
 };
 
 static int a100_r_pinctrl_probe(struct platform_device *pdev)
diff --git a/drivers/pinctrl/sunxi/pinctrl-sun50i-a100.c b/drivers/pinctrl/sunxi/pinctrl-sun50i-a100.c
index e69f6da40dc0..f682e0e4244d 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sun50i-a100.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sun50i-a100.c
@@ -684,7 +684,7 @@ static const struct sunxi_pinctrl_desc a100_pinctrl_data = {
 	.npins = ARRAY_SIZE(a100_pins),
 	.irq_banks = 7,
 	.irq_bank_map = a100_irq_bank_map,
-	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_SEL,
+	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_CTL,
 };
 
 static int a100_pinctrl_probe(struct platform_device *pdev)
diff --git a/drivers/pinctrl/sunxi/pinctrl-sun50i-h616.c b/drivers/pinctrl/sunxi/pinctrl-sun50i-h616.c
index 152b71226a80..d6ca720ee8d8 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sun50i-h616.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sun50i-h616.c
@@ -525,7 +525,7 @@ static const struct sunxi_pinctrl_desc h616_pinctrl_data = {
 	.irq_banks = ARRAY_SIZE(h616_irq_bank_map),
 	.irq_bank_map = h616_irq_bank_map,
 	.irq_read_needs_mux = true,
-	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_SEL,
+	.io_bias_cfg_variant = BIAS_VOLTAGE_PIO_POW_MODE_CTL,
 };
 
 static int h616_pinctrl_probe(struct platform_device *pdev)
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
index 3c5e71359ca8..eb3d595f816a 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c
@@ -662,6 +662,16 @@ static int sunxi_pinctrl_set_io_bias_cfg(struct sunxi_pinctrl *pctl,
 		reg &= ~IO_BIAS_MASK;
 		writel(reg | val, pctl->membase + sunxi_grp_config_reg(pin));
 		return 0;
+	case BIAS_VOLTAGE_PIO_POW_MODE_CTL:
+		val = uV > 1800000 && uV <= 2500000 ? BIT(bank) : 0;
+
+		raw_spin_lock_irqsave(&pctl->lock, flags);
+		reg = readl(pctl->membase + PIO_POW_MOD_CTL_REG);
+		reg &= ~BIT(bank);
+		writel(reg | val, pctl->membase + PIO_POW_MOD_CTL_REG);
+		raw_spin_unlock_irqrestore(&pctl->lock, flags);
+
+		fallthrough;
 	case BIAS_VOLTAGE_PIO_POW_MODE_SEL:
 		val = uV <= 1800000 ? 1 : 0;
 
diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.h b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
index a32bb5bcb754..0f1aab58650c 100644
--- a/drivers/pinctrl/sunxi/pinctrl-sunxi.h
+++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.h
@@ -98,6 +98,7 @@
 #define PINCTRL_SUN8I_V3S	BIT(10)
 
 #define PIO_POW_MOD_SEL_REG	0x340
+#define PIO_POW_MOD_CTL_REG	0x344
 
 enum sunxi_desc_bias_voltage {
 	BIAS_VOLTAGE_NONE,
@@ -111,6 +112,12 @@ enum sunxi_desc_bias_voltage {
 	 * register, as seen on H6 SoC, for example.
 	 */
 	BIAS_VOLTAGE_PIO_POW_MODE_SEL,
+	/*
+	 * Bias voltage is set through PIO_POW_MOD_SEL_REG
+	 * and PIO_POW_MOD_CTL_REG register, as seen on
+	 * A100 and D1 SoC, for example.
+	 */
+	BIAS_VOLTAGE_PIO_POW_MODE_CTL,
 };
 
 struct sunxi_desc_function {
-- 
2.35.1