soc/amd/common/block/i2c/i23c_pad_ctr: add & use I23C pad configuration

I2C bus 0..2 on Sabrina uses a different pad type which supports 1.1V
and 1.8V levels, but doesn't support 3.3V I2C levels. Compared to the
existing I2C pad control registers the bit definitions are different, so
add a separate function to configure those pads which however still has
the same function signature and is compatible with same data structs
used for the devicetree settings. PPR #57243 Rev 1.50 was used as a
reference.

TEST=None

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: Ie210c3437f2608d1e9fb99dcb151fc4190721375
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61570
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>

src/soc/amd/common/block/i2c/Kconfig

@@ -8,3 +8,9 @@ config SOC_AMD_COMMON_BLOCK_I2C_PAD_CTRL
 	help
 	  Select this option to add FCH I2C pad configuration functions to the
 	  build.
+
+config SOC_AMD_COMMON_BLOCK_I23C_PAD_CTRL
+	bool
+	help
+	  Select this option to add FCH I2C/I3C pad configuration functions to
+	  the build.

src/soc/amd/common/block/i2c/Makefile.inc

@@ -1,2 +1,3 @@
 all-$(CONFIG_SOC_AMD_COMMON_BLOCK_I2C) += i2c.c
 all-$(CONFIG_SOC_AMD_COMMON_BLOCK_I2C_PAD_CTRL) += i2c_pad_ctrl.c
+all-$(CONFIG_SOC_AMD_COMMON_BLOCK_I23C_PAD_CTRL) += i23c_pad_ctrl.c

src/soc/amd/common/block/i2c/i23c_pad_ctrl.c

@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <amdblocks/acpimmio.h>
+#include <amdblocks/i2c.h>
+#include <console/console.h>
+#include <types.h>
+#include "i23c_pad_def.h"
+
+void fch_i23c_pad_init(unsigned int bus,
+		       enum i2c_speed speed,
+		       const struct i2c_pad_control *ctrl)
+{
+	uint32_t pad_ctrl;
+
+	pad_ctrl = misc_read32(MISC_I23C_PAD_CTRL(bus));
+
+	pad_ctrl &= ~I23C_PAD_CTRL_MODE_I3C_I2C_MASK;
+	pad_ctrl |= I23C_PAD_CTRL_MODE_I2C;
+
+	switch (ctrl->rx_level) {
+	case I2C_PAD_RX_NO_CHANGE:
+		/* Default is enabled and thresholds for 1.8V operation */
+		break;
+	case I2C_PAD_RX_OFF:
+		pad_ctrl &= ~I23C_PAD_CTRL_RX_SEL_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_RX_SEL_OFF;
+		pad_ctrl &= ~I23C_PAD_CTRL_MODE_1_8V_1_1V_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_MODE_1_8V;
+		break;
+	case I2C_PAD_RX_1_8V:
+		pad_ctrl &= ~I23C_PAD_CTRL_RX_SEL_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_RX_SEL_ON;
+		pad_ctrl &= ~I23C_PAD_CTRL_MODE_1_8V_1_1V_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_MODE_1_8V;
+		break;
+	case I2C_PAD_RX_1_1V:
+		pad_ctrl &= ~I23C_PAD_CTRL_RX_SEL_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_RX_SEL_ON;
+		pad_ctrl &= ~I23C_PAD_CTRL_MODE_1_8V_1_1V_MASK;
+		pad_ctrl |= I23C_PAD_CTRL_MODE_1_1V;
+		break;
+	default:
+		printk(BIOS_WARNING, "Invalid I2C/I3C pad RX level for bus %u\n", bus);
+		break;
+	}
+
+	pad_ctrl &= ~I23C_PAD_CTRL_FALLSLEW_SEL_MASK;
+	pad_ctrl |= speed == I2C_SPEED_STANDARD ?
+		I23C_PAD_CTRL_FALLSLEW_SEL_STD : I23C_PAD_CTRL_FALLSLEW_SEL_LOW;
+
+	pad_ctrl &= I23C_PAD_CTRL_SLEW_N_MASK;
+	pad_ctrl |= I23C_PAD_CTRL_SLEW_N_FAST;
+
+	misc_write32(MISC_I23C_PAD_CTRL(bus), pad_ctrl);
+}

src/soc/amd/common/block/i2c/i23c_pad_def.h

@@ -0,0 +1,64 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef AMD_BLOCK_I23C_PAD_DEF_H
+#define AMD_BLOCK_I23C_PAD_DEF_H
+
+#include <types.h>
+
+/* MISC_I2Cx_PAD_CTRL and MISC_I23Cx_PAD_CTRL are in the same place, but have different bit
+   definitions. Which one is present depends on the SoC. */
+#define MISC_I23C0_PAD_CTRL		0xd8
+#define MISC_I23C_PAD_CTRL(bus)		(MISC_I23C0_PAD_CTRL + 4 * (bus))
+
+#define   I23C_PAD_CTRL_OD_RP_SW_MASK	(BIT(0) | BIT(1) | BIT(2) | BIT(3))
+#define     I23C_PAD_CTRL_OD_RP_SW_SHIFT	0
+#define   I23C_PAD_CTRL_RX_SEL_MASK		(BIT(4) | BIT(5))
+#define     I23C_PAD_CTRL_RX_SHIFT		4
+#define     I23C_PAD_CTRL_RX_SEL_OFF		(0 << I23C_PAD_CTRL_RX_SHIFT)
+#define     I23C_PAD_CTRL_RX_SEL_ON		(3 << I23C_PAD_CTRL_RX_SHIFT)
+#define   I23C_PAD_CTRL_SLEW_N_MASK		(BIT(6) | BIT(7))
+#define     I23C_PAD_CTRL_SLEW_N_SHIFT		7
+#define     I23C_PAD_CTRL_SLEW_N_DIS		(0 << I23C_PAD_CTRL_SLEW_N_SHIFT)
+#define     I23C_PAD_CTRL_SLEW_N_FAST		(3 << I23C_PAD_CTRL_SLEW_N_SHIFT)
+#define   I23C_PAD_CTRL_FALLSLEW_SEL_MASK	(BIT(8) | BIT(9))
+#define     I23C_PAD_CTRL_FALLSLEW_SEL_SHIFT	8
+#define     I23C_PAD_CTRL_FALLSLEW_SEL_STD	(0 << I23C_PAD_CTRL_FALLSLEW_SEL_SHIFT)
+#define     I23C_PAD_CTRL_FALLSLEW_SEL_LOW	(3 << I23C_PAD_CTRL_FALLSLEW_SEL_SHIFT)
+#define   I23C_PAD_CTRL_SPIKE_RC_EN_MASK	(BIT(10) | BIT(11))
+#define     I23C_PAD_CTRL_SPIKE_RC_EN_SHIFT	10
+#define     I23C_PAD_CTRL_SPIKE_RC_DIS		(0 << I23C_PAD_CTRL_SPIKE_RC_EN_SHIFT)
+#define     I23C_PAD_CTRL_SPIKE_RC_EN		(3 << I23C_PAD_CTRL_SPIKE_RC_EN_SHIFT)
+#define   I23C_PAD_CTRL_CAP_DOWN		BIT(12)
+#define   I23C_PAD_CTRL_CAP_UP			BIT(13)
+#define   I23C_PAD_CTRL_RES_DOWN		BIT(14)
+#define   I23C_PAD_CTRL_RES_UP			BIT(15)
+#define   I23C_PAD_CTRL_BIAS_CRT_EN_MASK	(BIT(16) | BIT(17))
+#define     I23C_PAD_CTRL_BIAS_CRT_EN_SHIFT	16
+#define     I23C_PAD_CTRL_BIAS_CRT_DIS		(0 << I23C_PAD_CTRL_BIAS_CRT_EN_SHIFT)
+#define     I23C_PAD_CTRL_BIAS_CRT_EN		(3 << I23C_PAD_CTRL_BIAS_CRT_EN_SHIFT)
+#define   I23C_PAD_CTRL_SPARE0			BIT(18)
+#define   I23C_PAD_CTRL_SPARE1			BIT(19)
+#define   I23C_PAD_CTRL_COMP_SEL0		BIT(20) /* unused */
+#define   I23C_PAD_CTRL_COMP_SEL1		BIT(21) /* unused */
+#define   I23C_PAD_CTRL_RES_BIAS_EN_MASK	(BIT(22) | BIT(23))
+#define     I23C_PAD_CTRL_RES_BIAS_EN_SHIFT	22
+#define     I23C_PAD_CTRL_RES_BIAS_T_COMP	(0 << I23C_PAD_CTRL_RES_BIAS_EN_SHIFT)
+#define     I23C_PAD_CTRL_RES_BIAS_CONST_GM	(3 << I23C_PAD_CTRL_RES_BIAS_EN_SHIFT)
+#define   I23C_PAD_CTRL_SLEW_P_MASK		(BIT(24) | BIT(25))
+#define     I23C_PAD_CTRL_SLEW_P_SHIFT		24
+#define     I23C_PAD_CTRL_SLEW_P_DIS		(0 << I23C_PAD_CTRL_SLEW_P_SHIFT)
+#define     I23C_PAD_CTRL_SLEW_P_EN		(3 << I23C_PAD_CTRL_SLEW_P_SHIFT)
+#define   I23C_PAD_CTRL_MODE_I3C_I2C_MASK	(BIT(26) | BIT(27))
+#define     I23C_PAD_CTRL_MODE_I3C_I2C_SHIFT	26
+#define     I23C_PAD_CTRL_MODE_I2C		(0 << I23C_PAD_CTRL_MODE_I3C_I2C_SHIFT)
+#define     I23C_PAD_CTRL_MODE_I3C		(3 << I23C_PAD_CTRL_MODE_I3C_I2C_SHIFT)
+#define   I23C_PAD_CTRL_MODE_1_8V_1_1V_MASK	(BIT(28) | BIT(29))
+#define     I23C_PAD_CTRL_MODE_1_8V_1_1V_SHIFT	28
+#define     I23C_PAD_CTRL_MODE_1_1V		(0 << I23C_PAD_CTRL_MODE_1_8V_1_1V_SHIFT)
+#define     I23C_PAD_CTRL_MODE_1_8V		(3 << I23C_PAD_CTRL_MODE_1_8V_1_1V_SHIFT)
+#define   I23C_PAD_CTRL_SPIKE_C_SEL_MASK	(BIT(30) | BIT(31))
+#define     I23C_PAD_CTRL_SPIKE_C_SEL_SHIFT	30
+#define     I23C_PAD_CTRL_SPIKE_C_SEL_DIS	(0 << I23C_PAD_CTRL_SPIKE_C_SEL_SHIFT)
+#define     I23C_PAD_CTRL_SPIKE_C_SEL_EN	(3 << I23C_PAD_CTRL_SPIKE_C_SEL_SHIFT)
+
+#endif /* AMD_BLOCK_I23C_PAD_DEF_H */

src/soc/amd/common/block/i2c/i2c_pad_def.h

@@ -5,6 +5,8 @@
 
 #include <types.h>
 
+/* MISC_I2Cx_PAD_CTRL and MISC_I23Cx_PAD_CTRL are in the same place, but have different bit
+   definitions. Which one is present depends on the SoC. */
 #define MISC_I2C0_PAD_CTRL		0xd8
 #define MISC_I2C_PAD_CTRL(bus)		(MISC_I2C0_PAD_CTRL + 4 * (bus))
 

src/soc/amd/common/block/include/amdblocks/i2c.h

@@ -61,6 +61,7 @@ enum i2c_pad_rx_level {
 	I2C_PAD_RX_OFF,
 	I2C_PAD_RX_3_3V,
 	I2C_PAD_RX_1_8V,
+	I2C_PAD_RX_1_1V,
 };
 
 struct i2c_pad_control {
@@ -71,6 +72,10 @@ void fch_i2c_pad_init(unsigned int bus,
 		      enum i2c_speed speed,
 		      const struct i2c_pad_control *ctrl);
 
+void fch_i23c_pad_init(unsigned int bus,
+		       enum i2c_speed speed,
+		       const struct i2c_pad_control *ctrl);
+
 /* Helper function to perform misc I2C configuration specific to SoC. */
 void soc_i2c_misc_init(unsigned int bus, const struct dw_i2c_bus_config *cfg);
 

src/soc/amd/sabrina/Kconfig

@@ -53,6 +53,7 @@ config SOC_SPECIFIC_OPTIONS
 	select SOC_AMD_COMMON_BLOCK_HAS_ESPI	# TODO: Check if this is still correct
 	select SOC_AMD_COMMON_BLOCK_I2C		# TODO: Check if this is still correct
 	select SOC_AMD_COMMON_BLOCK_I2C_PAD_CTRL
+	select SOC_AMD_COMMON_BLOCK_I23C_PAD_CTRL
 	select SOC_AMD_COMMON_BLOCK_IOMMU	# TODO: Check if this is still correct
 	select SOC_AMD_COMMON_BLOCK_LPC		# TODO: Check if this is still correct
 	select SOC_AMD_COMMON_BLOCK_MCAX	# TODO: Check if this is still correct

src/soc/amd/sabrina/i2c.c

@@ -41,7 +41,12 @@ void soc_i2c_misc_init(unsigned int bus, const struct dw_i2c_bus_config *cfg)
 	if (bus >= ARRAY_SIZE(config->i2c_pad))
 		return;
 
-	fch_i2c_pad_init(bus, cfg->speed, &config->i2c_pad[bus]);
+	/* The I/O pads of I2C0..2 are the new I23C pads and the I/O pads of I2C3 still are the
+	   same I2C pads as in Picasso and Cezanne. */
+	if (bus <= 2)
+		fch_i23c_pad_init(bus, cfg->speed, &config->i2c_pad[bus]);
+	else
+		fch_i2c_pad_init(bus, cfg->speed, &config->i2c_pad[bus]);
 }
 
 const struct soc_i2c_ctrlr_info *soc_get_i2c_ctrlr_info(size_t *num_ctrlrs)