soc/amd/common/block/i2c: move raw GPIO access functions to gpio_banks

The I2C code should use some GPIO API to access the GPIO registers
instead of accessing the GPIO MMIO regions itself.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I84dff381ad86e0c7f879f0f079186aec9cafc604
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56779
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

3 files changed, 20 insertions, 21 deletions

diff --git a/src/soc/amd/common/block/gpio_banks/gpio.c b/src/soc/amd/common/block/gpio_banks/gpio.c
index b3c1ac1b72..d0e8281f2a 100644
--- a/src/soc/amd/common/block/gpio_banks/gpio.c
+++ b/src/soc/amd/common/block/gpio_banks/gpio.c
@@ -166,6 +166,19 @@ static void set_gpio_mux(gpio_t gpio, uint8_t function)
 	iomux_read8(gpio); /* Flush posted write */
 }
 
+void gpio_save_pin_registers(gpio_t gpio, struct soc_amd_gpio_register_save *save)
+{
+	save->mux_value = iomux_read8(gpio);
+	save->control_value = gpio_read32(gpio);
+}
+
+void gpio_restore_pin_registers(gpio_t gpio, struct soc_amd_gpio_register_save *save)
+{
+	set_gpio_mux(gpio, save->mux_value);
+	gpio_write32(gpio, save->control_value);
+	gpio_read32(gpio); /* Flush posted write */
+}
+
 static void set_single_gpio(const struct soc_amd_gpio *g)
 {
 	static const struct soc_amd_event *gev_tbl;
diff --git a/src/soc/amd/common/block/i2c/i2c.c b/src/soc/amd/common/block/i2c/i2c.c
index 8a9a663383..8e79b4cabc 100644
--- a/src/soc/amd/common/block/i2c/i2c.c
+++ b/src/soc/amd/common/block/i2c/i2c.c
@@ -130,25 +130,6 @@ struct device_operations soc_amd_i2c_mmio_ops = {
 	.acpi_fill_ssdt = dw_i2c_acpi_fill_ssdt,
 };
 
-/*
- * To program I2C pins without destroying their programming, the registers
- * that will be changed need to be saved first.
- */
-static void save_i2c_pin_registers(uint8_t gpio, struct soc_amd_gpio_register_save *save_table)
-{
-	save_table->mux_value = iomux_read8(gpio);
-	save_table->control_value = gpio_read32(gpio);
-}
-
-static void restore_i2c_pin_registers(uint8_t gpio, struct soc_amd_gpio_register_save *save_table)
-{
-	/* Write and flush posted writes. */
-	iomux_write8(gpio, save_table->mux_value);
-	iomux_read8(gpio);
-	gpio_write32(gpio, save_table->control_value);
-	gpio_read32(gpio);
-}
-
 static void drive_scl(const struct soc_i2c_peripheral_reset_info *reset_info, int val)
 {
 	size_t j;
@@ -179,7 +160,9 @@ void sb_reset_i2c_peripherals(const struct soc_i2c_peripheral_reset_info *reset_
 
 	/* Save and reprogram I2C SCL pins */
 	for (i = 0; i < reset_info->num_pins; i++) {
-		save_i2c_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
+		/* To program I2C pins without destroying their programming, the registers
+		   that will be changed need to be saved first */
+		gpio_save_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
 		/* Program SCL GPIO as output driven high */
 		program_gpios(&reset_info->i2c_scl[i].pin, 1);
 	}
@@ -195,5 +178,5 @@ void sb_reset_i2c_peripherals(const struct soc_i2c_peripheral_reset_info *reset_
 
 	/* Restore I2C pins. */
 	for (i = 0; i < reset_info->num_pins; i++)
-		restore_i2c_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
+		gpio_restore_pin_registers(reset_info->i2c_scl[i].pin.gpio, &save_table[i]);
 }
diff --git a/src/soc/amd/common/block/include/amdblocks/gpio_banks.h b/src/soc/amd/common/block/include/amdblocks/gpio_banks.h
index 8f36b24313..bb82c10d75 100644
--- a/src/soc/amd/common/block/include/amdblocks/gpio_banks.h
+++ b/src/soc/amd/common/block/include/amdblocks/gpio_banks.h
@@ -91,4 +91,7 @@ int gpio_interrupt_status(gpio_t gpio);
 /* Implemented by soc, provides table of available GPIO mapping to Gevents */
 void soc_get_gpio_event_table(const struct soc_amd_event **table, size_t *items);
 
+void gpio_save_pin_registers(gpio_t gpio, struct soc_amd_gpio_register_save *save);
+void gpio_restore_pin_registers(gpio_t gpio, struct soc_amd_gpio_register_save *save);
+
 #endif /* AMD_BLOCK_GPIO_BANKS_H */