Commit Graph

12 Commits

Author SHA1 Message Date
Yi Pei
b8f370aa37 lib: utils/serial: Clear LSR status and check RBR status
On some platforms, read RBR when it is empty may result in an error.

Signed-off-by: Yi Pei <neopimail@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/CAFPVDjQZ1gpf8-u--RBbAL1Y0FfDN2vZ3g=wBw+Bp-8ppuz3HA@mail.gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>
2025-07-20 20:37:18 +05:30
Junhui Liu
8fe835303c lib: utils/serial: Add PXA UARTs support
The PXA variant of the uart8250 adds the UART Unit Enable bit (UUE) that
needs to be set to enable the XScale PXA UART. And it is required for
some RISC-V SoCs like the Spacemit K1 that implement the PXA UART.

This introduces the "intel,xscale-uart" compatible to handle setting the
UUE bit.

Signed-off-by: Junhui Liu <junhui.liu@pigmoral.tech>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250327-pxa-uart-support-v2-1-c4400c1fcd0b@pigmoral.tech
Signed-off-by: Anup Patel <anup@brainfault.org>
2025-03-27 20:20:05 +05:30
Yu Chien Peter Lin
a12542316c lib: utils/serial: Ensure proper allocation of PMP entries for uart8250
The added memory region should start from the base address.
Otherwise, the range will be shifted by reg_offset and not
able to merge consecutive NAPOT regions in the root domain,
resulting in wasted PMP entries.

Fixes: e8bc1621 ("lib: utils/serial: Add shared regions for
serial drivers")

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2023-10-06 16:53:25 +05:30
Mayuresh Chitale
e8bc1621c6 lib: utils/serial: Add shared regions for serial drivers
The serial driver regions used by OpenSBI should be marked as a shared
read-write regions between M-mode and SU-mode as those are accessed
by earlycon and the corresponding tty serial drivers running in 'S' mode.
When the smepmp extension is enabled, PMP entries for these shared regions
will get programmed.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
2023-09-24 17:04:41 +05:30
Andrew Jones
f27203525a lib: utils/serial: Ensure baudrate is non-zero before using
RISC-V doesn't generate exceptions on divide-by-zero, but the result,
all bits set, is not likely what people expect either. In all cases
where we divide by baudrate there's a chance it's zero (when the DT
it came from is "bad"). To avoid difficult to debug situations, leave
baudrate dependent registers alone when baudrate is zero, as, also in
all cases, it appears we can skip initialization of those registers
and still [hopefully] have a functioning UART.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-07-30 11:39:42 +05:30
Zong Li
5c5cbb53a4 lib: utils/serial: support 'reg-offset' property
reg-offset property is used for offset to apply to the mapbase
from the start of the registers in 8250 UART. In Linux kernel,
it has been handled in 8250 UART driver.

dt-bindings:
<linux>/Documentation/devicetree/bindings/serial/8250.yaml

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-04-17 13:57:48 +05:30
Jakub Luzny
ce4c0188d9 lib: utils/serial: Round UART8250 baud rate divisor to nearest integer
Previously, it was rounded down and that gives suboptimal results when
non-standard clock sources or baud rates are used.

Signed-off-by: Jakub Luzny <jakub.luzny@codasip.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-02-04 11:16:29 +05:30
Jukka Laitinen
5d025eb235 lib: fix pointer of type 'void *' used in arithmetic
Using "void *" in arithmetic causes errors with strict compiler settings:
"error: pointer of type 'void *' used in arithmetic [-Werror=pointer-arith]"

Avoid these by calculating on "char *" where 1-byte data size is assumed.

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
Reviewed-by: Dong Du <Dd_nirvana@sjtu.edu.cn>
Reviewed-by: Xiang W <wxjstz@126.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2022-01-21 21:58:12 +05:30
Anup Patel
068ca086af lib: sbi: Simplify console platform operations
Instead of having console_putc() and console_getc() callbacks in
platform operations, it will be much simpler for console driver to
directly register these operations as device to the sbi_console
implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
2021-04-28 16:58:23 +05:30
Anup Patel
e6c1345f89 lib: utils/serial: Skip baudrate config if input frequency is zero
We should skip baudrate config for UART8250 and SiFive UART when
input frequency is zero.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
2020-05-01 09:36:13 +05:30
Bin Meng
078686d75c lib: serial: Fix coding style issues
This fixes various coding style issues found in the serial codes.
No functional changes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup.patel@wdc.com>
2020-03-10 10:38:08 +05:30
Atish Patra
793e5e1184 platform: Move platform common to lib/utils.
Currently, platform/common contains platform/non-platform specific
common minimal drivers and libraries. This is helpful is all platforms
are built within opensbi framework.

Move them to lib/utils so that any external platform code also can
reuse the minimalistic drivers or other common libraries.

This patch doesn't introduce any functional changes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:56 +05:30