linux/drivers/tty/serial
Stuart Menefy 5086e0a409 tty: serial: samsung: Enable baud clock during initialisation
The Exynos 5260, like the 5433, appears to require baud clock as
well as pclk to be running before accessing any of the registers,
otherwise an external abort is raised.

The serial driver already enables baud clock when required, but only
if it knows which clock is baud clock. On older SoCs baud clock may be
selected from a number of possible clocks so to support this the driver
only selects which clock to use for baud clock when a port is opened,
at which point the desired baud rate is known and the best clock can be
selected.

The result is that there are a number of circumstances in which
registers are accessed without first explicitly enabling baud clock:
 - while the driver is being initialised
 - the initial parts of opening a port for the first time
 - when resuming if the port hasn't been already opened

The 5433 overcomes this currently by marking the baud clock as
CLK_IGNORE_UNUSED, so the clock is always enabled, however
for the 5260 I've been trying to avoid this.

This change adds code to pick the first available clock to use
as baud clock and enables it while initialising the driver.

This code wouldn't be sufficient on a SoC which supports
multiple possible baud clock sources _and_ requires the
correct baud clock to be enabled before accessing any of the
serial port registers (in particular the register which selects
which clock to use as the baud clock).  As far as I know
such hardware doesn't exist.

Signed-off-by: Stuart Menefy <stuart.menefy@mathembedded.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19 13:42:08 +01:00
..
8250 serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup() 2019-02-13 19:48:57 +01:00
cpm_uart mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
jsm tty: serial: jsm: remove redundant pointer ch 2018-07-13 15:36:32 +02:00
21285.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
altera_jtaguart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
altera_uart.c serial: altera: set RRDY flag also without irq 2018-02-28 13:30:09 +01:00
amba-pl010.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
amba-pl011.c serial: set suppress_bind_attrs flag only if builtin 2018-11-09 09:07:17 -08:00
amba-pl011.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
apbuart.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
apbuart.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ar933x_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
arc_uart.c serial: arc_uart: Fix out-of-bounds access through DT alias 2018-02-28 15:29:59 +01:00
atmel_serial.c tty/serial: atmel: add ISO7816 support 2018-10-02 13:38:55 -07:00
atmel_serial.h tty/serial: atmel: add ISO7816 support 2018-10-02 13:38:55 -07:00
bcm63xx_uart.c MIPS changes for 4.15 2017-11-15 11:36:08 -08:00
clps711x.c serial: clps711x: Remove board support 2019-01-08 16:55:18 +01:00
digicolor-usart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
dz.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
dz.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
earlycon-arm-semihost.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
earlycon-riscv-sbi.c tty/serial: use uart_console_write in the RISC-V SBL early console 2019-01-23 15:41:50 -08:00
earlycon.c earlycon: Remove hardcoded port->uartclk initialization in of_setup_earlycon 2018-05-14 13:41:05 +02:00
efm32-uart.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
fsl_lpuart.c serial: fsl_lpuart: DMA support for 32-bit variant 2019-01-30 09:31:30 +01:00
icom.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
icom.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ifx6x60.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
ifx6x60.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
imx.c serial: imx: fix error handling in console_setup 2018-11-27 09:56:20 +01:00
ioc3_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ioc4_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
ip22zilog.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
ip22zilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig serial: Add Tegra Combined UART driver 2019-01-30 09:31:31 +01:00
kgdb_nmi.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
kgdboc.c kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var() 2018-12-06 15:59:07 +01:00
lantiq.c serial: lantiq: Do not swap register read/writes 2019-01-08 16:53:36 +01:00
lpc32xx_hs.c tty: serial: lpc32xx_hs: fix missing console boot messages 2019-01-18 11:23:00 +01:00
Makefile serial: Add Tegra Combined UART driver 2019-01-30 09:31:31 +01:00
max310x.c serial: max310x: Correction of the initial setting of the MODE1 bits for various supported ICs. 2019-02-08 10:14:28 +01:00
max3100.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mcf.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
men_z135_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
meson_uart.c tty: serial: meson: if no alias specified use an available id 2019-01-18 11:22:22 +01:00
mpc52xx_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
mps2-uart.c serial: mps2-uart: Add parentheses around conditional in mps2_uart_shutdown 2019-01-31 19:34:10 +01:00
mpsc.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
msm_serial.c tty: serial: msm_serial: Add __maybe_unused to suspend/resume callbacks 2018-05-14 13:41:05 +02:00
mux.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
mvebu-uart.c serial: mvebu-uart: initialize over sampling stack register 2018-11-27 09:20:17 +01:00
mxs-auart.c serial: mxs-auart: Fix potential infinite loop 2018-09-18 16:07:24 +02:00
netx-serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
omap-serial.c tty: omap-serial: Fix initial on-boot RTS GPIO level 2018-01-09 16:45:17 +01:00
owl-uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pch_uart.c pch_uart: remove set but not used variable 'tx_empty' 2018-11-09 09:07:17 -08:00
pic32_uart.c serial: set suppress_bind_attrs flag only if builtin 2018-11-09 09:07:17 -08:00
pic32_uart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
pmac_zilog.c tty: Use of_node_name_{eq,prefix} for node name comparisons 2018-12-17 16:12:17 +01:00
pmac_zilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pnx8xxx_uart.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
pxa.c serial: pxa: Fix an error handling path in 'serial_pxa_probe()' 2018-06-28 21:07:54 +09:00
qcom_geni_serial.c Merge 5.0-rc4 into tty-next 2019-01-28 08:22:00 +01:00
rda-uart.c tty: serial: Add RDA8810PL UART driver 2018-12-31 13:10:01 -08:00
rp2.c treewide: devm_kzalloc() -> devm_kcalloc() 2018-06-12 16:19:22 -07:00
sa1100.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
samsung.c tty: serial: samsung: Enable baud clock during initialisation 2019-02-19 13:42:08 +01:00
samsung.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sb1250-duart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sc16is7xx.c sc16is7xx: Use struct_size() in devm_kzalloc() 2019-01-08 16:56:04 +01:00
sccnxp.c serial: sccnxp: Allow to use non-standard baud rates 2018-12-20 16:26:59 +01:00
serial-tegra.c serial: tegra: fix some spelling mistakes 2018-11-09 08:58:18 -08:00
serial_core.c tty: serial: remove redundant likely annotation 2019-02-19 13:42:07 +01:00
serial_ks8695.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_mctrl_gpio.c gpiolib: Pass array info to get/set array functions 2018-09-13 11:16:54 +02:00
serial_mctrl_gpio.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
serial_txx9.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sh-sci.c Merge 5.0-rc6 into tty-next 2019-02-11 09:26:45 +01:00
sh-sci.h serial: sh-sci: Support for HSCIF RX sampling point adjustment 2018-04-23 10:08:18 +02:00
sirfsoc_uart.c serial: sirf: Fix out-of-bounds access through DT alias 2018-02-28 15:30:00 +01:00
sirfsoc_uart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
sn_console.c TTY: sn_console: Replace spin_is_locked() with spin_trylock() 2018-10-04 11:06:35 -07:00
sprd_serial.c serial: sprd: Fix the indentation issue 2018-09-18 16:07:24 +02:00
st-asc.c tty: serial: simplify getting .drvdata 2018-04-22 17:29:43 +02:00
stm32-usart.c serial: stm32: fix initialization of RS485 mode 2018-03-15 17:39:43 +01:00
stm32-usart.h serial: stm32: add support for RS485 hardware control mode 2018-03-14 13:35:37 +01:00
suncore.c tty: Use of_node_name_{eq,prefix} for node name comparisons 2018-12-17 16:12:17 +01:00
sunhv.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
sunsab.c treewide: kzalloc() -> kcalloc() 2018-06-12 16:19:22 -07:00
sunsab.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sunsu.c TTY/Serial driver patches for 4.21-rc1 2018-12-28 20:33:54 -08:00
sunzilog.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
sunzilog.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tegra-tcu.c serial: Add Tegra Combined UART driver 2019-01-30 09:31:31 +01:00
timbuart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
timbuart.h tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
uartlite.c serial-uartlite: fix null pointer dereference on pointer port 2018-11-27 09:08:15 +01:00
ucc_uart.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
vr41xx_siu.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
vt8500_serial.c tty: serial: Remove redundant license text 2017-11-08 13:08:12 +01:00
xilinx_uartps.c serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFO 2019-02-19 13:42:07 +01:00
zs.c tty: add SPDX identifiers to all remaining files in drivers/tty/ 2017-11-08 13:08:12 +01:00
zs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00