From patchwork Thu Feb 27 15:21:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 236956 List-Id: U-Boot discussion From: andriy.shevchenko at linux.intel.com (Andy Shevchenko) Date: Thu, 27 Feb 2020 17:21:54 +0200 Subject: [PATCH v1 1/3] dm: serial: Add clock member to struct serial_device_info Message-ID: <20200227152156.87385-1-andriy.shevchenko@linux.intel.com> Some callers of serial_getinfo() would like to know the UART base clock speed in order to make decision what to pass to OS in some cases. In particular, ACPI SPCR table expects only certain base clock speed and thus we have to act accordingly. Signed-off-by: Andy Shevchenko Reviewed-by: Simon Glass Reviewed-by: Bin Meng --- drivers/serial/sandbox.c | 1 + include/serial.h | 3 +++ test/dm/serial.c | 1 + 3 files changed, 5 insertions(+) diff --git a/drivers/serial/sandbox.c b/drivers/serial/sandbox.c index 1af5cc12f3..545ff3f747 100644 --- a/drivers/serial/sandbox.c +++ b/drivers/serial/sandbox.c @@ -198,6 +198,7 @@ static int sandbox_serial_getinfo(struct udevice *dev, .reg_width = 1, .reg_offset = 0, .reg_shift = 0, + .clock = SERIAL_DEFAULT_CLOCK, }; if (!serial_info) diff --git a/include/serial.h b/include/serial.h index 104f34ff91..54b21a0470 100644 --- a/include/serial.h +++ b/include/serial.h @@ -139,6 +139,7 @@ enum adr_space_type { * @reg_width: size (in bytes) of the IO accesses to the registers * @reg_offset: offset to apply to the @addr from the start of the registers * @reg_shift: quantity to shift the register offsets by + * @clock: UART base clock speed in Hz * @baudrate: baud rate */ struct serial_device_info { @@ -148,10 +149,12 @@ struct serial_device_info { u8 reg_width; u8 reg_offset; u8 reg_shift; + unsigned int clock; unsigned int baudrate; }; #define SERIAL_DEFAULT_ADDRESS 0xBADACCE5 +#define SERIAL_DEFAULT_CLOCK (16 * 115200) /** * struct struct dm_serial_ops - Driver model serial operations diff --git a/test/dm/serial.c b/test/dm/serial.c index 3d741a8c36..c6be6ab7ab 100644 --- a/test/dm/serial.c +++ b/test/dm/serial.c @@ -29,6 +29,7 @@ static int dm_test_serial(struct unit_test_state *uts) ut_assertok(serial_getinfo(dev_serial, &info_serial)); ut_assert(info_serial.type == SERIAL_CHIP_UNKNOWN); ut_assert(info_serial.addr == SERIAL_DEFAULT_ADDRESS); + ut_assert(info_serial.clock == SERIAL_DEFAULT_CLOCK); /* * test with a parameter which is NULL pointer */ From patchwork Thu Feb 27 15:21:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 236955 List-Id: U-Boot discussion From: andriy.shevchenko at linux.intel.com (Andy Shevchenko) Date: Thu, 27 Feb 2020 17:21:55 +0200 Subject: [PATCH v1 2/3] serial: ns16550: Provide UART base clock speed in ->getinfo() In-Reply-To: <20200227152156.87385-1-andriy.shevchenko@linux.intel.com> References: <20200227152156.87385-1-andriy.shevchenko@linux.intel.com> Message-ID: <20200227152156.87385-2-andriy.shevchenko@linux.intel.com> Some callers may need the UART base clock speed value. Provide it in the ->getinfo() callback. Signed-off-by: Andy Shevchenko Reviewed-by: Simon Glass Reviewed-by: Bin Meng --- drivers/serial/ns16550.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index 1fcbc35015..386b5e04c8 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -476,6 +476,7 @@ static int ns16550_serial_getinfo(struct udevice *dev, info->reg_width = plat->reg_width; info->reg_shift = plat->reg_shift; info->reg_offset = plat->reg_offset; + info->clock = plat->clock; return 0; } From patchwork Thu Feb 27 15:21:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 236954 List-Id: U-Boot discussion From: andriy.shevchenko at linux.intel.com (Andy Shevchenko) Date: Thu, 27 Feb 2020 17:21:56 +0200 Subject: [PATCH v1 3/3] x86: acpi: Let OS know that console already had been initialized In-Reply-To: <20200227152156.87385-1-andriy.shevchenko@linux.intel.com> References: <20200227152156.87385-1-andriy.shevchenko@linux.intel.com> Message-ID: <20200227152156.87385-3-andriy.shevchenko@linux.intel.com> SPCR has no clue if the UART base clock speed is different to the default one. However, the SPCR 1.04 defines baud rate 0 as a preconfigured state of UART and OS is supposed not to touch the configuration of the serial device. Linux kernel supports that starting from v5.0, see commit b413b1abeb21 ("ACPI: SPCR: Consider baud rate 0 as preconfigured state") for the details. Signed-off-by: Andy Shevchenko Reviewed-by: Bin Meng --- arch/x86/lib/acpi_table.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index 66e32f21bd..074987e294 100644 --- a/arch/x86/lib/acpi_table.c +++ b/arch/x86/lib/acpi_table.c @@ -471,6 +471,15 @@ static void acpi_create_spcr(struct acpi_spcr *spcr) spcr->pci_device_id = 0xffff; spcr->pci_vendor_id = 0xffff; + /* + * SPCR has no clue if the UART base clock speed is different + * to the default one. However, the SPCR 1.04 defines baud rate + * 0 as a preconfigured state of UART and OS is supposed not + * to touch the configuration of the serial device. + */ + if (serial_info.clock != SERIAL_DEFAULT_CLOCK) + spcr->baud_rate = 0; + /* Fix checksum */ header->checksum = table_compute_checksum((void *)spcr, header->length); }