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From:   Claudiu <claudiu.beznea@tuxon.dev>
To:     s.shtylyov@omp.ru, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
        geert+renesas@glider.be, magnus.damm@gmail.com,
        mturquette@baylibre.com, sboyd@kernel.org,
        linus.walleij@linaro.org, prabhakar.mahadev-lad.rj@bp.renesas.com,
        biju.das.jz@bp.renesas.com
Cc:     linux-renesas-soc@vger.kernel.org, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org,
        Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Subject: [PATCH v2 05/11] pinctrl: renesas: rzg2l: Add support to select power source for Ethernet pins
Date:   Thu,  7 Dec 2023 09:06:54 +0200
Message-Id: <20231207070700.4156557-6-claudiu.beznea.uj@bp.renesas.com>
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From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

The GPIO controller available on RZ/G3S (but also on RZ/G2L) allows setting
the power source for Ethernet pins. Based on the interface b/w the Ethernet
controller and the Ethernet PHY and board design specific power source need
to be selected. The GPIO controller allows 1.8V, 2.5V and 3.3V power source
selection for Ethernet pins. This could be selected though ETHX_POC
registers (X={0, 1}).

Commit adjust the driver to support this and does proper instantiation for
RZ/G3S and RZ/G2L SoC. On RZ/G2L only get operation has been tested at the
moment.

While at it, as the power registers on RZ/G2L support access sizes of 8
bits and RZ/G3S support access sizes of 8/16/32 bits, changed
writel()/readl() on these registers with writeb()/readb(). This should
allow using the same code for both SoCs w/o any issues.

Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v2:
- removed PVDD_MASK
- use 8 bit helpers to get/set value of power register
- replaced if/else with switch/case everywhere

 drivers/pinctrl/renesas/pinctrl-rzg2l.c | 42 +++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
index 58786455ecf3..6b082161e821 100644
--- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
+++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
@@ -107,8 +107,10 @@
 #define IEN(off)		(0x1800 + (off) * 8)
 #define ISEL(off)		(0x2C00 + (off) * 8)
 #define SD_CH(off, ch)		((off) + (ch) * 4)
+#define ETH_POC(off, ch)	((off) + (ch) * 4)
 #define QSPI			(0x3008)
 
+#define PVDD_2500		2	/* I/O domain voltage 2.5V */
 #define PVDD_1800		1	/* I/O domain voltage <= 1.8V */
 #define PVDD_3300		0	/* I/O domain voltage >= 3.3V */
 
@@ -116,7 +118,6 @@
 #define PWPR_PFCWE		BIT(6)	/* PFC Register Write Enable */
 
 #define PM_MASK			0x03
-#define PVDD_MASK		0x01
 #define PFC_MASK		0x07
 #define IEN_MASK		0x01
 #define IOLH_MASK		0x03
@@ -135,10 +136,12 @@
  * struct rzg2l_register_offsets - specific register offsets
  * @pwpr: PWPR register offset
  * @sd_ch: SD_CH register offset
+ * @eth_poc: ETH_POC register offset
  */
 struct rzg2l_register_offsets {
 	u16 pwpr;
 	u16 sd_ch;
+	u16 eth_poc;
 };
 
 /**
@@ -604,6 +607,10 @@ static int rzg2l_caps_to_pwr_reg(const struct rzg2l_register_offsets *regs, u32
 		return SD_CH(regs->sd_ch, 0);
 	if (caps & PIN_CFG_IO_VMC_SD1)
 		return SD_CH(regs->sd_ch, 1);
+	if (caps & PIN_CFG_IO_VMC_ETH0)
+		return ETH_POC(regs->eth_poc, 0);
+	if (caps & PIN_CFG_IO_VMC_ETH1)
+		return ETH_POC(regs->eth_poc, 1);
 	if (caps & PIN_CFG_IO_VMC_QSPI)
 		return QSPI;
 
@@ -615,6 +622,7 @@ static int rzg2l_get_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps
 	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
 	const struct rzg2l_register_offsets *regs = &hwcfg->regs;
 	int pwr_reg;
+	u8 val;
 
 	if (caps & PIN_CFG_SOFT_PS)
 		return pctrl->settings[pin].power_source;
@@ -623,7 +631,18 @@ static int rzg2l_get_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps
 	if (pwr_reg < 0)
 		return pwr_reg;
 
-	return (readl(pctrl->base + pwr_reg) & PVDD_MASK) ? 1800 : 3300;
+	val = readb(pctrl->base + pwr_reg);
+	switch (val) {
+	case PVDD_1800:
+		return 1800;
+	case PVDD_2500:
+		return 2500;
+	case PVDD_3300:
+		return 3300;
+	default:
+		/* Should not happen. */
+		return -EINVAL;
+	}
 }
 
 static int rzg2l_set_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps, u32 ps)
@@ -631,17 +650,32 @@ static int rzg2l_set_power_source(struct rzg2l_pinctrl *pctrl, u32 pin, u32 caps
 	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
 	const struct rzg2l_register_offsets *regs = &hwcfg->regs;
 	int pwr_reg;
+	u8 val;
 
 	if (caps & PIN_CFG_SOFT_PS) {
 		pctrl->settings[pin].power_source = ps;
 		return 0;
 	}
 
+	switch (ps) {
+	case 1800:
+		val = PVDD_1800;
+		break;
+	case 2500:
+		val = PVDD_2500;
+		break;
+	case 3300:
+		val = PVDD_3300;
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	pwr_reg = rzg2l_caps_to_pwr_reg(regs, caps);
 	if (pwr_reg < 0)
 		return pwr_reg;
 
-	writel((ps == 1800) ? PVDD_1800 : PVDD_3300, pctrl->base + pwr_reg);
+	writeb(val, pctrl->base + pwr_reg);
 	pctrl->settings[pin].power_source = ps;
 
 	return 0;
@@ -1885,6 +1919,7 @@ static const struct rzg2l_hwcfg rzg2l_hwcfg = {
 	.regs = {
 		.pwpr = 0x3014,
 		.sd_ch = 0x3000,
+		.eth_poc = 0x300c,
 	},
 	.iolh_groupa_ua = {
 		/* 3v3 power source */
@@ -1897,6 +1932,7 @@ static const struct rzg2l_hwcfg rzg3s_hwcfg = {
 	.regs = {
 		.pwpr = 0x3000,
 		.sd_ch = 0x3004,
+		.eth_poc = 0x3010,
 	},
 	.iolh_groupa_ua = {
 		/* 1v8 power source */
-- 
2.39.2