| Message ID | 20230425120459.13413-2-venkatesh.abbarapu@amd.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Simon Glass |
| Headers | show |
| Series | Add support to fetch baudrate from dtb | expand |
Hi Venkatesh, On Tue, 25 Apr 2023 at 06:05, Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com> wrote: > > From: Algapally Santosh Sagar <santoshsagar.algapally@amd.com> > > The baudrate configured in .config is taken by default by serial. If > change of baudrate is required then the .config needs to changed and > u-boot recompilation is required or the u-boot environment needs to be > updated. > > To avoid this, support is added to fetch the baudrate directly from the > device tree file and update. > The serial, prints the log with the configured baudrate in the dtb. > The commit c4df0f6f315c ("arm: mvebu: Espressobin: Set default value for > $fdtfile env variable") is taken as reference for changing the default > environment variable. > > The default environment stores the default baudrate value, When default > baudrate and dtb baudrate are not same glitches are seen on the serial. > So, the environment also needs to be updated with the dtb baudrate to > avoid the glitches on the serial. > > Signed-off-by: Algapally Santosh Sagar <santoshsagar.algapally@amd.com> > Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com> > --- > drivers/serial/serial-uclass.c | 32 +++++++++++++++++++++++++++ > include/env_default.h | 7 ++++-- > include/env_internal.h | 2 +- > include/fdtdec.h | 8 +++++++ > include/serial.h | 1 + > lib/fdtdec.c | 40 ++++++++++++++++++++++++++++++++++ > 6 files changed, 87 insertions(+), 3 deletions(-) Can you please add something to doc/ for this feature? > > diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c > index 067fae2614..d77d3bda36 100644 > --- a/drivers/serial/serial-uclass.c > +++ b/drivers/serial/serial-uclass.c > @@ -154,12 +154,44 @@ static void serial_find_console_or_panic(void) > } > #endif /* CONFIG_SERIAL_PRESENT */ > > +#ifdef CONFIG_SERIAL_DT_BAUD Please drop this #ifdef > +int serial_get_valid_baudrate(int baud) > +{ > + int i; > + > + for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) { > + if (baud == baudrate_table[i]) > + return 0; > + } > + > + return -EINVAL; > +} > +#endif > + > /* Called prior to relocation */ > int serial_init(void) > { > #if CONFIG_IS_ENABLED(SERIAL_PRESENT) > serial_find_console_or_panic(); > gd->flags |= GD_FLG_SERIAL_READY; > +#ifdef CONFIG_SERIAL_DT_BAUD if (IS_ENABLED(CONFIG_SERIAL_DT_BAUD) You also should add a Kconfig option. I suggest naming it OF_SERIAL_BOARD since we typically put an OF_ prefix on such options. > + int ret = 0; > + char *ptr = &default_environment[0]; > + > + /* > + * Fetch the baudrate from the dtb and update the value in the > + * default environment. > + */ > + ret = fdtdec_get_baud_from_dtb(gd->fdt_blob); > + if (ret != -EINVAL && ret != -EFAULT) { > + gd->baudrate = ret; > + > + while (*ptr != '\0' && *(ptr + 1) != '\0') > + ptr++; > + ptr += 2; > + sprintf(ptr, "baudrate=%d", gd->baudrate); > + } > +#endif > serial_setbrg(); > #endif > > diff --git a/include/env_default.h b/include/env_default.h > index c0df39d62f..4f286ffc9e 100644 > --- a/include/env_default.h > +++ b/include/env_default.h > @@ -23,7 +23,7 @@ env_t embedded_environment __UBOOT_ENV_SECTION__(environment) = { > { > #elif defined(DEFAULT_ENV_INSTANCE_STATIC) > static char default_environment[] = { > -#elif defined(DEFAULT_ENV_IS_RW) > +#elif defined(CONFIG_DEFAULT_ENV_IS_RW) > char default_environment[] = { > #else > const char default_environment[] = { > @@ -44,7 +44,7 @@ const char default_environment[] = { > #if defined(CONFIG_BOOTDELAY) > "bootdelay=" __stringify(CONFIG_BOOTDELAY) "\0" > #endif > -#if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0) > +#if !defined(CONFIG_SERIAL_DT_BAUD) && defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0) > "baudrate=" __stringify(CONFIG_BAUDRATE) "\0" > #endif > #ifdef CONFIG_LOADS_ECHO > @@ -120,6 +120,9 @@ const char default_environment[] = { > #endif > #ifdef CFG_EXTRA_ENV_SETTINGS > CFG_EXTRA_ENV_SETTINGS > +#endif > +#ifdef CONFIG_SERIAL_DT_BAUD > + "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" What is this for? > #endif > "\0" > #else /* CONFIG_USE_DEFAULT_ENV_FILE */ > diff --git a/include/env_internal.h b/include/env_internal.h > index 6a69494646..fcb464263f 100644 > --- a/include/env_internal.h > +++ b/include/env_internal.h > @@ -89,7 +89,7 @@ typedef struct environment_s { > extern env_t embedded_environment; > #endif /* ENV_IS_EMBEDDED */ > > -#ifdef DEFAULT_ENV_IS_RW > +#ifdef CONFIG_DEFAULT_ENV_IS_RW What is this change for? > extern char default_environment[]; > #else > extern const char default_environment[]; > diff --git a/include/fdtdec.h b/include/fdtdec.h > index aa61a0fca1..48937a7a46 100644 > --- a/include/fdtdec.h > +++ b/include/fdtdec.h > @@ -657,6 +657,14 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node, > */ > int fdtdec_get_alias_highest_id(const void *blob, const char *base); Could you make this an ofnode_...() function instead? Then you can call ofnode_read_chosen_string() from your function. We are trying to drop the fdtdec API. > > +/** > + * Get baudrate from the dtb > + * > + * @param blob Device tree blob (if NULL, then error is returned) > + * @return Baud rate value, or -ve error . Return: Baud ... (we changed to that syntax to work with Sphinx) But this should become ofnode_read_baud(void) Exported functions should be documented in the header file, not the C file > + */ > +int fdtdec_get_baud_from_dtb(const void *blob); > + > /** > * Get a property from the /chosen node > * > diff --git a/include/serial.h b/include/serial.h > index 42bdf3759c..48834b517c 100644 > --- a/include/serial.h > +++ b/include/serial.h > @@ -337,6 +337,7 @@ int serial_setconfig(struct udevice *dev, uint config); > */ > int serial_getinfo(struct udevice *dev, struct serial_device_info *info); > > +int serial_get_valid_baudrate(int baud); check_valid_baudrate() would be better since it is checking the provided rate, not returning a valid rate (as I understand it). This needs function docs > void atmel_serial_initialize(void); > void mcf_serial_initialize(void); > void mpc85xx_serial_initialize(void); > diff --git a/lib/fdtdec.c b/lib/fdtdec.c > index 0827e16859..2fcc12148e 100644 > --- a/lib/fdtdec.c > +++ b/lib/fdtdec.c > @@ -570,6 +570,46 @@ int fdtdec_get_alias_highest_id(const void *blob, const char *base) > return max; > } > > +#ifdef CONFIG_SERIAL_DT_BAUD > +int fdtdec_get_baud_from_dtb(const void *blob) > +{ > + const char *str, *p, *baud_start; > + u32 baud; > + > + if (!blob) > + return -EFAULT; > + > + str = fdtdec_get_chosen_prop(blob, "stdout-path"); > + if (!str) > + return -EINVAL; > + > + p = strchr(str, ':'); > + if (!p) > + return -EINVAL; > + > + baud = 0; > + baud_start = p + 1; It would help to have a comment about the format you are parsing, e.g. an example string. I thought it was something like: "serial0:115200n8" in which case I think you could do: p = strchr(str, ':') if (p) { uint baud = dectoul(p + 1, NULL); ... } > + while (*baud_start != '\0') { > + /* > + * Uart binding is <baud>{<parity>{<bits>{...}}} > + * So the baudrate either is the whole string, or > + * ends in the parity characters. > + */ > + if (*baud_start == 'n' || *baud_start == 'o' || > + *baud_start == 'e') > + break; > + > + baud = baud * 10 + (*baud_start - '0'); > + baud_start++; > + } > + > + if (serial_get_valid_baudrate(baud) == -EINVAL) > + return -EINVAL; ret = func ... if (ret) return ret (i.e. don't change the error number, and catch all errors that it might return) > + > + return baud; > +} > +#endif > + > const char *fdtdec_get_chosen_prop(const void *blob, const char *name) > { > int chosen_node; > -- > 2.17.1 > Regards, Simon
Hi Simon, Thanks, A Santosh Sagar. > -----Original Message----- > From: Simon Glass <sjg@chromium.org> > Sent: Tuesday, April 25, 2023 11:31 PM > To: Abbarapu, Venkatesh <venkatesh.abbarapu@amd.com> > Cc: u-boot@lists.denx.de; Simek, Michal <michal.simek@amd.com>; > git@xilinx.com; Algapally, Santosh Sagar <SantoshSagar.Algapally@amd.com> > Subject: Re: [PATCH v3 1/2] serial: zynqmp: Fetch baudrate from dtb and update > > Caution: This message originated from an External Source. Use proper caution > when opening attachments, clicking links, or responding. > > > Hi Venkatesh, > > On Tue, 25 Apr 2023 at 06:05, Venkatesh Yadav Abbarapu > <venkatesh.abbarapu@amd.com> wrote: > > > > From: Algapally Santosh Sagar <santoshsagar.algapally@amd.com> > > > > The baudrate configured in .config is taken by default by serial. If > > change of baudrate is required then the .config needs to changed and > > u-boot recompilation is required or the u-boot environment needs to be > > updated. > > > > To avoid this, support is added to fetch the baudrate directly from > > the device tree file and update. > > The serial, prints the log with the configured baudrate in the dtb. > > The commit c4df0f6f315c ("arm: mvebu: Espressobin: Set default value > > for $fdtfile env variable") is taken as reference for changing the > > default environment variable. > > > > The default environment stores the default baudrate value, When > > default baudrate and dtb baudrate are not same glitches are seen on the > serial. > > So, the environment also needs to be updated with the dtb baudrate to > > avoid the glitches on the serial. > > > > Signed-off-by: Algapally Santosh Sagar > > <santoshsagar.algapally@amd.com> > > Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com> > > --- > > drivers/serial/serial-uclass.c | 32 +++++++++++++++++++++++++++ > > include/env_default.h | 7 ++++-- > > include/env_internal.h | 2 +- > > include/fdtdec.h | 8 +++++++ > > include/serial.h | 1 + > > lib/fdtdec.c | 40 ++++++++++++++++++++++++++++++++++ > > 6 files changed, 87 insertions(+), 3 deletions(-) > > Can you please add something to doc/ for this feature? Ok sure > > > > > diff --git a/drivers/serial/serial-uclass.c > > b/drivers/serial/serial-uclass.c index 067fae2614..d77d3bda36 100644 > > --- a/drivers/serial/serial-uclass.c > > +++ b/drivers/serial/serial-uclass.c > > @@ -154,12 +154,44 @@ static void serial_find_console_or_panic(void) > > } > > #endif /* CONFIG_SERIAL_PRESENT */ > > > > +#ifdef CONFIG_SERIAL_DT_BAUD > > Please drop this #ifdef Will drop > > > +int serial_get_valid_baudrate(int baud) { > > + int i; > > + > > + for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) { > > + if (baud == baudrate_table[i]) > > + return 0; > > + } > > + > > + return -EINVAL; > > +} > > +#endif > > + > > /* Called prior to relocation */ > > int serial_init(void) > > { > > #if CONFIG_IS_ENABLED(SERIAL_PRESENT) > > serial_find_console_or_panic(); > > gd->flags |= GD_FLG_SERIAL_READY; > > +#ifdef CONFIG_SERIAL_DT_BAUD > > if (IS_ENABLED(CONFIG_SERIAL_DT_BAUD) On using this if (IS_ENABLED(CONFIG_SERIAL_DT_BAUD)) The variables declared below are getting compiled and the below warning is thrown. So, not changing this. drivers/serial/serial-uclass.c: In function 'serial_init': drivers/serial/serial-uclass.c:189:21: warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers] 189 | char *ptr = &default_environment[0]; > > You also should add a Kconfig option. I suggest naming it OF_SERIAL_BOARD > since we typically put an OF_ prefix on such options. > Will change SERIAL_DT_BAUD to OF_SERIAL_DT_BAUD > > + int ret = 0; > > + char *ptr = &default_environment[0]; > > + > > + /* > > + * Fetch the baudrate from the dtb and update the value in the > > + * default environment. > > + */ > > + ret = fdtdec_get_baud_from_dtb(gd->fdt_blob); > > + if (ret != -EINVAL && ret != -EFAULT) { > > + gd->baudrate = ret; > > + > > + while (*ptr != '\0' && *(ptr + 1) != '\0') > > + ptr++; > > + ptr += 2; > > + sprintf(ptr, "baudrate=%d", gd->baudrate); > > + } > > +#endif > > serial_setbrg(); > > #endif > > > > diff --git a/include/env_default.h b/include/env_default.h index > > c0df39d62f..4f286ffc9e 100644 > > --- a/include/env_default.h > > +++ b/include/env_default.h > > @@ -23,7 +23,7 @@ env_t embedded_environment > __UBOOT_ENV_SECTION__(environment) = { > > { > > #elif defined(DEFAULT_ENV_INSTANCE_STATIC) > > static char default_environment[] = { -#elif > > defined(DEFAULT_ENV_IS_RW) > > +#elif defined(CONFIG_DEFAULT_ENV_IS_RW) > > char default_environment[] = { > > #else > > const char default_environment[] = { > > @@ -44,7 +44,7 @@ const char default_environment[] = { #if > > defined(CONFIG_BOOTDELAY) > > "bootdelay=" __stringify(CONFIG_BOOTDELAY) "\0" > > #endif > > -#if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0) > > +#if !defined(CONFIG_SERIAL_DT_BAUD) && defined(CONFIG_BAUDRATE) && > > +(CONFIG_BAUDRATE >= 0) > > "baudrate=" __stringify(CONFIG_BAUDRATE) "\0" > > #endif > > #ifdef CONFIG_LOADS_ECHO > > @@ -120,6 +120,9 @@ const char default_environment[] = { #endif > > #ifdef CFG_EXTRA_ENV_SETTINGS > > CFG_EXTRA_ENV_SETTINGS > > +#endif > > +#ifdef CONFIG_SERIAL_DT_BAUD > > + "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" > > What is this for? The padding is needed at the end of default environment for baudrate when environment is writable. > > > #endif > > "\0" > > #else /* CONFIG_USE_DEFAULT_ENV_FILE */ diff --git > > a/include/env_internal.h b/include/env_internal.h index > > 6a69494646..fcb464263f 100644 > > --- a/include/env_internal.h > > +++ b/include/env_internal.h > > @@ -89,7 +89,7 @@ typedef struct environment_s { extern env_t > > embedded_environment; #endif /* ENV_IS_EMBEDDED */ > > > > -#ifdef DEFAULT_ENV_IS_RW > > +#ifdef CONFIG_DEFAULT_ENV_IS_RW > > What is this change for? This is done as DEFAULT_ENV_IS_RW is moved to Kconfig. > > > extern char default_environment[]; > > #else > > extern const char default_environment[]; diff --git > > a/include/fdtdec.h b/include/fdtdec.h index aa61a0fca1..48937a7a46 > > 100644 > > --- a/include/fdtdec.h > > +++ b/include/fdtdec.h > > @@ -657,6 +657,14 @@ int fdtdec_get_alias_seq(const void *blob, const char > *base, int node, > > */ > > int fdtdec_get_alias_highest_id(const void *blob, const char *base); > > Could you make this an ofnode_...() function instead? Then you can call > ofnode_read_chosen_string() from your function. > > We are trying to drop the fdtdec API. Will change > > > > > +/** > > + * Get baudrate from the dtb > > + * > > + * @param blob Device tree blob (if NULL, then error is returned) > > + * @return Baud rate value, or -ve error . > > Return: Baud ... > > (we changed to that syntax to work with Sphinx) > > But this should become ofnode_read_baud(void) > > Exported functions should be documented in the header file, not the C file > Will do > > + */ > > +int fdtdec_get_baud_from_dtb(const void *blob); > > + > > /** > > * Get a property from the /chosen node > > * > > diff --git a/include/serial.h b/include/serial.h index > > 42bdf3759c..48834b517c 100644 > > --- a/include/serial.h > > +++ b/include/serial.h > > @@ -337,6 +337,7 @@ int serial_setconfig(struct udevice *dev, uint config); > > */ > > int serial_getinfo(struct udevice *dev, struct serial_device_info > > *info); > > > > +int serial_get_valid_baudrate(int baud); > > check_valid_baudrate() would be better since it is checking the provided rate, > not returning a valid rate (as I understand it). > > This needs function docs Ok sure > > void atmel_serial_initialize(void); > > void mcf_serial_initialize(void); > > void mpc85xx_serial_initialize(void); diff --git a/lib/fdtdec.c > > b/lib/fdtdec.c index 0827e16859..2fcc12148e 100644 > > --- a/lib/fdtdec.c > > +++ b/lib/fdtdec.c > > @@ -570,6 +570,46 @@ int fdtdec_get_alias_highest_id(const void *blob, > const char *base) > > return max; > > } > > > > +#ifdef CONFIG_SERIAL_DT_BAUD > > +int fdtdec_get_baud_from_dtb(const void *blob) { > > + const char *str, *p, *baud_start; > > + u32 baud; > > + > > + if (!blob) > > + return -EFAULT; > > + > > + str = fdtdec_get_chosen_prop(blob, "stdout-path"); > > + if (!str) > > + return -EINVAL; > > + > > + p = strchr(str, ':'); > > + if (!p) > > + return -EINVAL; > > + > > + baud = 0; > > + baud_start = p + 1; > > It would help to have a comment about the format you are parsing, e.g. > an example string. > > I thought it was something like: "serial0:115200n8" in which case I think you > could do: > > p = strchr(str, ':') > if (p) { > uint baud = dectoul(p + 1, NULL); > > ... > > } Will do > > + while (*baud_start != '\0') { > > + /* > > + * Uart binding is <baud>{<parity>{<bits>{...}}} > > + * So the baudrate either is the whole string, or > > + * ends in the parity characters. > > + */ > > + if (*baud_start == 'n' || *baud_start == 'o' || > > + *baud_start == 'e') > > + break; > > + > > + baud = baud * 10 + (*baud_start - '0'); > > + baud_start++; > > + } > > + > > + if (serial_get_valid_baudrate(baud) == -EINVAL) > > + return -EINVAL; > > ret = func ... > if (ret) > return ret > > (i.e. don't change the error number, and catch all errors that it might return) > Ok sure > > + > > + return baud; > > +} > > +#endif > > + > > const char *fdtdec_get_chosen_prop(const void *blob, const char > > *name) { > > int chosen_node; > > -- > > 2.17.1 > > > > Regards, > Simon Will do the changes and send v4
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c index 067fae2614..d77d3bda36 100644 --- a/drivers/serial/serial-uclass.c +++ b/drivers/serial/serial-uclass.c @@ -154,12 +154,44 @@ static void serial_find_console_or_panic(void) } #endif /* CONFIG_SERIAL_PRESENT */ +#ifdef CONFIG_SERIAL_DT_BAUD +int serial_get_valid_baudrate(int baud) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) { + if (baud == baudrate_table[i]) + return 0; + } + + return -EINVAL; +} +#endif + /* Called prior to relocation */ int serial_init(void) { #if CONFIG_IS_ENABLED(SERIAL_PRESENT) serial_find_console_or_panic(); gd->flags |= GD_FLG_SERIAL_READY; +#ifdef CONFIG_SERIAL_DT_BAUD + int ret = 0; + char *ptr = &default_environment[0]; + + /* + * Fetch the baudrate from the dtb and update the value in the + * default environment. + */ + ret = fdtdec_get_baud_from_dtb(gd->fdt_blob); + if (ret != -EINVAL && ret != -EFAULT) { + gd->baudrate = ret; + + while (*ptr != '\0' && *(ptr + 1) != '\0') + ptr++; + ptr += 2; + sprintf(ptr, "baudrate=%d", gd->baudrate); + } +#endif serial_setbrg(); #endif diff --git a/include/env_default.h b/include/env_default.h index c0df39d62f..4f286ffc9e 100644 --- a/include/env_default.h +++ b/include/env_default.h @@ -23,7 +23,7 @@ env_t embedded_environment __UBOOT_ENV_SECTION__(environment) = { { #elif defined(DEFAULT_ENV_INSTANCE_STATIC) static char default_environment[] = { -#elif defined(DEFAULT_ENV_IS_RW) +#elif defined(CONFIG_DEFAULT_ENV_IS_RW) char default_environment[] = { #else const char default_environment[] = { @@ -44,7 +44,7 @@ const char default_environment[] = { #if defined(CONFIG_BOOTDELAY) "bootdelay=" __stringify(CONFIG_BOOTDELAY) "\0" #endif -#if defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0) +#if !defined(CONFIG_SERIAL_DT_BAUD) && defined(CONFIG_BAUDRATE) && (CONFIG_BAUDRATE >= 0) "baudrate=" __stringify(CONFIG_BAUDRATE) "\0" #endif #ifdef CONFIG_LOADS_ECHO @@ -120,6 +120,9 @@ const char default_environment[] = { #endif #ifdef CFG_EXTRA_ENV_SETTINGS CFG_EXTRA_ENV_SETTINGS +#endif +#ifdef CONFIG_SERIAL_DT_BAUD + "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" #endif "\0" #else /* CONFIG_USE_DEFAULT_ENV_FILE */ diff --git a/include/env_internal.h b/include/env_internal.h index 6a69494646..fcb464263f 100644 --- a/include/env_internal.h +++ b/include/env_internal.h @@ -89,7 +89,7 @@ typedef struct environment_s { extern env_t embedded_environment; #endif /* ENV_IS_EMBEDDED */ -#ifdef DEFAULT_ENV_IS_RW +#ifdef CONFIG_DEFAULT_ENV_IS_RW extern char default_environment[]; #else extern const char default_environment[]; diff --git a/include/fdtdec.h b/include/fdtdec.h index aa61a0fca1..48937a7a46 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -657,6 +657,14 @@ int fdtdec_get_alias_seq(const void *blob, const char *base, int node, */ int fdtdec_get_alias_highest_id(const void *blob, const char *base); +/** + * Get baudrate from the dtb + * + * @param blob Device tree blob (if NULL, then error is returned) + * @return Baud rate value, or -ve error . + */ +int fdtdec_get_baud_from_dtb(const void *blob); + /** * Get a property from the /chosen node * diff --git a/include/serial.h b/include/serial.h index 42bdf3759c..48834b517c 100644 --- a/include/serial.h +++ b/include/serial.h @@ -337,6 +337,7 @@ int serial_setconfig(struct udevice *dev, uint config); */ int serial_getinfo(struct udevice *dev, struct serial_device_info *info); +int serial_get_valid_baudrate(int baud); void atmel_serial_initialize(void); void mcf_serial_initialize(void); void mpc85xx_serial_initialize(void); diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 0827e16859..2fcc12148e 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -570,6 +570,46 @@ int fdtdec_get_alias_highest_id(const void *blob, const char *base) return max; } +#ifdef CONFIG_SERIAL_DT_BAUD +int fdtdec_get_baud_from_dtb(const void *blob) +{ + const char *str, *p, *baud_start; + u32 baud; + + if (!blob) + return -EFAULT; + + str = fdtdec_get_chosen_prop(blob, "stdout-path"); + if (!str) + return -EINVAL; + + p = strchr(str, ':'); + if (!p) + return -EINVAL; + + baud = 0; + baud_start = p + 1; + while (*baud_start != '\0') { + /* + * Uart binding is <baud>{<parity>{<bits>{...}}} + * So the baudrate either is the whole string, or + * ends in the parity characters. + */ + if (*baud_start == 'n' || *baud_start == 'o' || + *baud_start == 'e') + break; + + baud = baud * 10 + (*baud_start - '0'); + baud_start++; + } + + if (serial_get_valid_baudrate(baud) == -EINVAL) + return -EINVAL; + + return baud; +} +#endif + const char *fdtdec_get_chosen_prop(const void *blob, const char *name) { int chosen_node;