Change in ...coreboot[master]: mb/emulation/qemu-riscv: Use generic 8250 uart driver

[Patrick Rudolph (Code Review)]

Patrick Rudolph has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/33735

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

mb/emulation/qemu-riscv: Use generic 8250 uart driver

Drop hacked uart code and use the generic 8250 uart driver for ns16550a.

Tested on qemu-system-riscv64:
* The UART is still working.

Change-Id: I6efda913fa39e0cfa466b52c570572aca90dacdf
Signed-off-by: Patrick Rudolph 
---
M src/mainboard/emulation/qemu-riscv/Kconfig
M src/mainboard/emulation/qemu-riscv/uart.c
2 files changed, 2 insertions(+), 35 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/35/33735/1

diff --git a/src/mainboard/emulation/qemu-riscv/Kconfig b/src/mainboard/emulation/qemu-riscv/Kconfig
index d15c99e..f0f658d 100644
--- a/src/mainboard/emulation/qemu-riscv/Kconfig
+++ b/src/mainboard/emulation/qemu-riscv/Kconfig
@@ -37,9 +37,9 @@
    def_bool y
    select SOC_UCB_RISCV
    select BOARD_ROMSIZE_KB_4096
-	select HAVE_UART_SPECIAL
    select BOOT_DEVICE_NOT_SPI_FLASH
    select MISSING_BOARD_RESET
+	select DRIVERS_UART_8250MEM

config MAINBOARD_DIR
    string
diff --git a/src/mainboard/emulation/qemu-riscv/uart.c b/src/mainboard/emulation/qemu-riscv/uart.c
index 021713a..271e994 100644
--- a/src/mainboard/emulation/qemu-riscv/uart.c
+++ b/src/mainboard/emulation/qemu-riscv/uart.c
@@ -15,42 +15,9 @@

#include <types.h>
 #include <console/uart.h>
-#include <boot/coreboot_tables.h>
 #include <mainboard/addressmap.h>

-static uint8_t *buf = (void *)QEMU_VIRT_UART0;
 uintptr_t uart_platform_base(int idx)
 {
-	return (uintptr_t) buf;
+	return (uintptr_t) QEMU_VIRT_UART0;
 }
-
-void uart_init(int idx)
-{
-}
-
-unsigned char uart_rx_byte(int idx)
-{
-	return *buf;
-}
-
-void uart_tx_byte(int idx, unsigned char data)
-{
-	*buf = data;
-}
-
-void uart_tx_flush(int idx)
-{
-}
-
-#ifndef __PRE_RAM__
-void uart_fill_lb(void *data)
-{
-	struct lb_serial serial;
-	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
-	serial.baseaddr = QEMU_VIRT_UART0;
-	serial.baud = 115200;
-	serial.regwidth = 1;
-	lb_add_serial(&serial, data);
-        lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
-}
-#endif

[Kyösti Mälkki (Code Review)]

Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

Patch Set 1:

The change brings in dependency of udelay(), so printk() before mtime_init() in riscv/mcall.c:hls_init() is wrong. It's BIOS_SPEW and UART code may never actually reach the udelay(), but there's a possible die() there in the path for this case.

Looking into riscv/arch_timer.c:timer_monotonic_get(), HLS()->time seems uninitialized and probably does not reference the intended hardware register SIFIVE_TIME_BASE (yet).
Also, I see SIFIVE_CLINT_TIMEBASE_FREQ 10+E6 in QEMU, assuming 10 MHz or 1/10 us per tick.

[Patrick Rudolph (Code Review)]

Patrick Rudolph has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

Patch Set 2:
> Patch Set 1:
>
> The change brings in dependency of udelay(), so printk() before mtime_init() in riscv/mcall.c:hls_init() is wrong. It's BIOS_SPEW and UART code may never actually reach the udelay(), but there's a possible die() there in the path for this case.
>
> Looking into riscv/arch_timer.c:timer_monotonic_get(), HLS()->time seems uninitialized and probably does not reference the intended hardware register SIFIVE_TIME_BASE (yet).
> Also, I see SIFIVE_CLINT_TIMEBASE_FREQ 10+E6 in QEMU, assuming 10 MHz or 1/10 us per tick.

Dropped debug code in a separate commit (https://review.coreboot.org/c/coreboot/+/33786). It has no effect anyway as console_init() hasn't been called yet.

[Kyösti Mälkki (Code Review)]

Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

Patch Set 2: Code-Review+1

Please check if the monotonic timer rate commented earlier is correct. (Unrelated, but I'll defer my +2 here due to that).

[Kyösti Mälkki (Code Review)]

Kyösti Mälkki has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

Patch Set 2: Code-Review+2

[Philipp Hug (Code Review)]

Philipp Hug has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

Patch Set 2: Code-Review+2

Thanks

[Patrick Rudolph (Code Review)]

Patrick Rudolph has submitted this change and it was merged. ( https://review.coreboot.org/c/coreboot/+/33735 )

Change subject: mb/emulation/qemu-riscv: Use generic 8250 uart driver
......................................................................

mb/emulation/qemu-riscv: Use generic 8250 uart driver

Drop hacked uart code and use the generic 8250 uart driver for ns16550a.

Tested on qemu-system-riscv64:
* The UART is still working.

Change-Id: I6efda913fa39e0cfa466b52c570572aca90dacdf
Signed-off-by: Patrick Rudolph 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33735
Reviewed-by: Kyösti Mälkki 
Reviewed-by: Philipp Hug 
Tested-by: build bot (Jenkins) 
---
M src/mainboard/emulation/qemu-riscv/Kconfig
M src/mainboard/emulation/qemu-riscv/uart.c
2 files changed, 2 insertions(+), 35 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Kyösti Mälkki: Looks good to me, approved
  Philipp Hug: Looks good to me, approved

diff --git a/src/mainboard/emulation/qemu-riscv/Kconfig b/src/mainboard/emulation/qemu-riscv/Kconfig
index d15c99e..f0f658d 100644
--- a/src/mainboard/emulation/qemu-riscv/Kconfig
+++ b/src/mainboard/emulation/qemu-riscv/Kconfig
@@ -37,9 +37,9 @@
    def_bool y
    select SOC_UCB_RISCV
    select BOARD_ROMSIZE_KB_4096
-	select HAVE_UART_SPECIAL
    select BOOT_DEVICE_NOT_SPI_FLASH
    select MISSING_BOARD_RESET
+	select DRIVERS_UART_8250MEM

config MAINBOARD_DIR
    string
diff --git a/src/mainboard/emulation/qemu-riscv/uart.c b/src/mainboard/emulation/qemu-riscv/uart.c
index 021713a..271e994 100644
--- a/src/mainboard/emulation/qemu-riscv/uart.c
+++ b/src/mainboard/emulation/qemu-riscv/uart.c
@@ -15,42 +15,9 @@

#include <types.h>
 #include <console/uart.h>
-#include <boot/coreboot_tables.h>
 #include <mainboard/addressmap.h>

-static uint8_t *buf = (void *)QEMU_VIRT_UART0;
 uintptr_t uart_platform_base(int idx)
 {
-	return (uintptr_t) buf;
+	return (uintptr_t) QEMU_VIRT_UART0;
 }
-
-void uart_init(int idx)
-{
-}
-
-unsigned char uart_rx_byte(int idx)
-{
-	return *buf;
-}
-
-void uart_tx_byte(int idx, unsigned char data)
-{
-	*buf = data;
-}
-
-void uart_tx_flush(int idx)
-{
-}
-
-#ifndef __PRE_RAM__
-void uart_fill_lb(void *data)
-{
-	struct lb_serial serial;
-	serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
-	serial.baseaddr = QEMU_VIRT_UART0;
-	serial.baud = 115200;
-	serial.regwidth = 1;
-	lb_add_serial(&serial, data);
-        lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
-}
-#endif