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authorAtish Patra <atishp@rivosinc.com>2023-11-24 08:09:04 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2024-01-10 16:04:05 +0100
commit88ead68e764cd164abb965e258c4e18841433ecf (patch)
tree12ffa2e9522e3ffc070a1618ef67a586c078e6d0 /drivers/tty/hvc
parenttty/serial: Add RISC-V SBI debug console based earlycon (diff)
downloadlinux-88ead68e764cd164abb965e258c4e18841433ecf.tar.xz
linux-88ead68e764cd164abb965e258c4e18841433ecf.zip
tty: Add SBI debug console support to HVC SBI driver
RISC-V SBI specification supports advanced debug console support via SBI DBCN extension. Extend the HVC SBI driver to support it. Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20231124070905.1043092-5-apatel@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers/tty/hvc')
-rw-r--r--drivers/tty/hvc/Kconfig2
-rw-r--r--drivers/tty/hvc/hvc_riscv_sbi.c37
2 files changed, 31 insertions, 8 deletions
diff --git a/drivers/tty/hvc/Kconfig b/drivers/tty/hvc/Kconfig
index 4f9264d005c0..6e05c5c7bca1 100644
--- a/drivers/tty/hvc/Kconfig
+++ b/drivers/tty/hvc/Kconfig
@@ -108,7 +108,7 @@ config HVC_DCC_SERIALIZE_SMP
config HVC_RISCV_SBI
bool "RISC-V SBI console support"
- depends on RISCV_SBI_V01
+ depends on RISCV_SBI
select HVC_DRIVER
help
This enables support for console output via RISC-V SBI calls, which
diff --git a/drivers/tty/hvc/hvc_riscv_sbi.c b/drivers/tty/hvc/hvc_riscv_sbi.c
index 31f53fa77e4a..2f3571f17ecd 100644
--- a/drivers/tty/hvc/hvc_riscv_sbi.c
+++ b/drivers/tty/hvc/hvc_riscv_sbi.c
@@ -39,21 +39,44 @@ static int hvc_sbi_tty_get(uint32_t vtermno, char *buf, int count)
return i;
}
-static const struct hv_ops hvc_sbi_ops = {
+static const struct hv_ops hvc_sbi_v01_ops = {
.get_chars = hvc_sbi_tty_get,
.put_chars = hvc_sbi_tty_put,
};
-static int __init hvc_sbi_init(void)
+static int hvc_sbi_dbcn_tty_put(uint32_t vtermno, const char *buf, int count)
{
- return PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_ops, 16));
+ return sbi_debug_console_write(buf, count);
}
-device_initcall(hvc_sbi_init);
-static int __init hvc_sbi_console_init(void)
+static int hvc_sbi_dbcn_tty_get(uint32_t vtermno, char *buf, int count)
{
- hvc_instantiate(0, 0, &hvc_sbi_ops);
+ return sbi_debug_console_read(buf, count);
+}
+
+static const struct hv_ops hvc_sbi_dbcn_ops = {
+ .put_chars = hvc_sbi_dbcn_tty_put,
+ .get_chars = hvc_sbi_dbcn_tty_get,
+};
+
+static int __init hvc_sbi_init(void)
+{
+ int err;
+
+ if (sbi_debug_console_available) {
+ err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_dbcn_ops, 256));
+ if (err)
+ return err;
+ hvc_instantiate(0, 0, &hvc_sbi_dbcn_ops);
+ } else if (IS_ENABLED(CONFIG_RISCV_SBI_V01)) {
+ err = PTR_ERR_OR_ZERO(hvc_alloc(0, 0, &hvc_sbi_v01_ops, 256));
+ if (err)
+ return err;
+ hvc_instantiate(0, 0, &hvc_sbi_v01_ops);
+ } else {
+ return -ENODEV;
+ }
return 0;
}
-console_initcall(hvc_sbi_console_init);
+device_initcall(hvc_sbi_init);