soc/amd/common/block/lpc: Split lpc_set_spibase() into two functions

This change splits lpc_set_spibase() into two separate functions:
lpc_set_spibase() - Sets MMIO base address for SPI controller and eSPI
controller (if supported by platforms)
lpc_enable_spi_rom() - Enables SPI ROM

This split is done to allow setting of MMIO base independent of ROM
enable bits. On platforms like Picasso, eSPI base is determined by the
same register and hence eSPI can set the BAR without having to touch
the enable bits.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I3f270ba1745b4bb8a403f00cd069a02e21d444be
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41247
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

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

@@ -179,6 +179,15 @@ int lpc_find_wideio_range(uint16_t start, uint16_t size);
 int lpc_set_wideio_range(uint16_t start, uint16_t size);
 
 uintptr_t lpc_get_spibase(void);
-void lpc_set_spibase(uint32_t base, uint32_t enable);
+
+/*
+ * Sets MMIO base address for SPI controller and eSPI controller (if supported by platform).
+ *
+ * eSPI base = SPI base + 0x10000
+ */
+void lpc_set_spibase(uint32_t base);
+
+/* Enable SPI ROM (SPI_ROM_ENABLE, SPI_ROM_ALT_ENABLE) */
+void lpc_enable_spi_rom(uint32_t enable);
 
 #endif /* __AMDBLOCKS_LPC_H__ */

src/soc/amd/common/block/lpc/lpc_util.c

@@ -322,19 +322,29 @@ uintptr_t lpc_get_spibase(void)
 	return (uintptr_t)base;
 }
 
-void lpc_set_spibase(u32 base, u32 enable)
+void lpc_set_spibase(uint32_t base)
 {
-	u32 reg32;
+	uint32_t reg32;
+
+	reg32 = pci_read_config32(_LPCB_DEV, SPIROM_BASE_ADDRESS_REGISTER);
+
+	reg32 &= SPI_BASE_ALIGNMENT - 1; /* preserve only reserved, enables */
+	reg32 |= ALIGN_DOWN(base, SPI_BASE_ALIGNMENT);
+
+	pci_write_config32(_LPCB_DEV, SPIROM_BASE_ADDRESS_REGISTER, reg32);
+}
+
+void lpc_enable_spi_rom(uint32_t enable)
+{
+	uint32_t reg32;
 
 	/* only two types of CS# enables are allowed */
 	enable &= SPI_ROM_ENABLE | SPI_ROM_ALT_ENABLE;
 
 	reg32 = pci_read_config32(_LPCB_DEV, SPIROM_BASE_ADDRESS_REGISTER);
 
-	reg32 &= SPI_BASE_ALIGNMENT - 1; /* preserve only reserved, enables */
 	reg32 &= ~(SPI_ROM_ENABLE | SPI_ROM_ALT_ENABLE);
 	reg32 |= enable;
-	reg32 |= ALIGN_DOWN(base, SPI_BASE_ALIGNMENT);
 
 	pci_write_config32(_LPCB_DEV, SPIROM_BASE_ADDRESS_REGISTER, reg32);
 }

src/soc/amd/picasso/southbridge.c

@@ -207,7 +207,9 @@ static uintptr_t sb_init_spi_base(void)
 	if (base)
 		return base;
 
-	lpc_set_spibase(SPI_BASE_ADDRESS, SPI_ROM_ENABLE);
+	lpc_set_spibase(SPI_BASE_ADDRESS);
+	lpc_enable_spi_rom(SPI_ROM_ENABLE);
+
 	return SPI_BASE_ADDRESS;
 }
 

src/soc/amd/stoneyridge/southbridge.c

@@ -265,7 +265,9 @@ static uintptr_t sb_init_spi_base(void)
 	if (base)
 		return base;
 
-	lpc_set_spibase(SPI_BASE_ADDRESS, SPI_ROM_ENABLE);
+	lpc_set_spibase(SPI_BASE_ADDRESS);
+	lpc_enable_spi_rom(SPI_ROM_ENABLE);
+
 	return SPI_BASE_ADDRESS;
 }