kernel/linux.git/drivers/tty/serial/amba-pl010.c, branch linux-4.4.y

serial: pl010: Drop CR register reset on set_termios

2022-01-27T07:46:18+00:00

[ Upstream commit 08a0c6dff91c965e39905cf200d22db989203ccb ] pl010_set_termios() briefly resets the CR register to zero. Where does this register write come from? The PL010 driver's IRQ handler ambauart_int() originally modified the CR register without holding the port spinlock. ambauart_set_termios() also modified that register. To prevent concurrent read-modify-writes by the IRQ handler and to prevent transmission while changing baudrate, ambauart_set_termios() had to disable interrupts. That is achieved by writing zero to the CR register. However in 2004 the PL010 driver was amended to acquire the port spinlock in the IRQ handler, obviating the need to disable interrupts in ->set_termios(): https://git.kernel.org/history/history/c/157c0342e591 That rendered the CR register write obsolete. Drop it. Cc: Russell King Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/fcaff16e5b1abb4cc3da5a2879ac13f278b99ed0.1641128728.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: Test/disable MSIs if switching from N_PPS

2014-11-06T22:57:27+00:00

Switching to the N_PPS line discipline may require enabling modem status interrupts; conversely switching from N_PPS may require disabling modem status interrupts. Affected drivers: 8250 amba-pl010 atmel Cc: Nicolas Ferre Cc: Russell King Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: Take uart port lock for direct *_enable_ms()

2014-11-06T22:57:27+00:00

Three UART drivers (8250, atmel & amba-pl010) directly call their enable_ms() method; the uart port lock must be acquired before any h/w programming. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: core: Pass termios to set_ldisc() notifications

2014-11-06T22:57:27+00:00

UART drivers which enable modem status interrupts when switching to N_PPS line discipline need to determine if modem status interrupts should be disabled when switching from N_PPS. Specifically, the set_ldisc() notification needs to evaluate UART_ENABLE_MS() which requires termios->c_cflag. Convert in-tree UART drivers to new interface. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: amba-pl010: use container_of to resolve uart_amba_port from uart_port

2014-11-06T03:20:52+00:00

Use container_of instead of casting first structure member. Signed-off-by: Fabian Frederick Signed-off-by: Greg Kroah-Hartman

serial: amba-pl010: Use devres APIs

2014-07-10T00:13:54+00:00

Migrating to use devres managed APIs devm_kzalloc, devm_ioremap and devm_clk_get. Signed-off-by: Tushar Behera Reviewed-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman

serial: Fix IGNBRK handling

2014-06-19T20:04:52+00:00

If IGNBRK is set without either BRKINT or PARMRK set, some uart drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the line discipline, when it should send either nothing or the TTYBREAK flag set. This happens because the read_status_mask masks out the BI condition, which uart_insert_char() then interprets as a normal 0x00 byte. SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General Terminal Interface - Input Modes, states: "If IGNBRK is set, a break condition detected on input shall be ignored; that is, not put on the input queue and therefore not read by any process." Fix read_status_mask to include the BI bit if IGNBRK is set; the lsr status retains the BI bit if a BREAK is recv'd, which is subsequently ignored in uart_insert_char() when masked with the ignore_status_mask. Affected drivers: 8250 - all serial_txx9 mfd amba-pl010 amba-pl011 atmel_serial bfin_uart dz ip22zilog max310x mxs-auart netx-serial pnx8xxx_uart pxa sb1250-duart sccnxp serial_ks8695 sirfsoc_uart st-asc vr41xx_siu zs sunzilog fsl_lpuart sunsab ucc_uart bcm63xx_uart sunsu efm32-uart pmac_zilog mpsc msm_serial m32r_sio Unaffected drivers: omap-serial rp2 sa1100 imx icom Annotated for fixes: altera_uart mcf Drivers without break detection: 21285 xilinx-uartps altera_jtaguart apbuart arc-uart clps711x max3100 uartlite msm_serial_hs nwpserial lantiq vt8500_serial Unknown: samsung mpc52xx_uart bfin_sport_uart cpm_uart/core Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag' Reported-by: Ivan Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: pl010: Convert to modern PM ops

2013-12-09T01:09:07+00:00

Convert to modern PM ops and use the SIMPLE_DEV_PM_OPS macro to set up the PM callbacks. Cc: Greg Kroah-Hartman Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman

serial: Remove unnecessary amba_set_drvdata()

2013-10-03T23:09:47+00:00

Driver core clears the driver data to NULL after device_release or on probe failure, so just remove it from here. Driver core change: "device-core: Ensure drvdata = NULL when no driver is bound" (sha1: 0998d0631001288a5974afc0b2a5f568bcdecb4d) Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman

serial: use dev_get_platdata()

2013-08-01T00:56:15+00:00

Use the wrapper function for retrieving the platform data instead of accessing dev->platform_data directly. Signed-off-by: Jingoo Han Signed-off-by: Greg Kroah-Hartman