linux/drivers/tty/serial/sh-sci.c, branch v6.16

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37Z

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

serial: sh-sci: Introduced sci_of_data

2025-04-11T14:56:32Z

The aim here is to provide an easier support to more different SCI controllers, like the RZ/T2H one. The existing .data field of_sci_match is changed to a structure containing all what that can be statically initialized, and avoid a call to 'sci_probe_regmap', in both 'sci_init_single', and 'early_console_setup'. 'sci_probe_regmap' is now assumed to be called in the only case where the device description is from a board file instead of a dts. In this way, there is no need to patch 'sci_probe_regmap' for adding new SCI type, and also, the specific sci_port_params for a new SCI type can be provided by an external file. Reviewed-by: Wolfram Sang Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Thierry Bultel Link: https://lore.kernel.org/r/20250403212919.1137670-10-thierry.bultel.yh@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Introduced function pointers

2025-04-11T14:56:30Z

The aim here is to prepare support for new sci controllers like the T2H/RSCI whose registers are too much different for being handled in common code. This named serial controller also has 32 bits register, so some return types had to be changed. The needed generic functions are no longer static, with prototypes defined in sh-sci-common.h so that they can be used from specific implementation in a separate file, to keep this driver as little changed as possible. For doing so, a set of 'ops' is added to struct sci_port. Tested-by: Geert Uytterhoeven Reviewed-by: Geert Uytterhoeven Reviewed-by: Wolfram Sang Signed-off-by: Thierry Bultel Link: https://lore.kernel.org/r/20250403212919.1137670-9-thierry.bultel.yh@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Fix a comment about SCIFA

2025-04-11T14:56:22Z

The comment was correct when it was added, at that time RZ/T1 was the only SoC in the RZ/T line. Since then, further SoCs have been added with RZ/T names which do not use the same SCIFA register layout and so the comment is now misleading. So we update the comment to explicitly reference only RZ/T1 SoCs. Reviewed-by: Paul Barker Reviewed-by: Wolfram Sang Reviewed-by: Geert Uytterhoeven Signed-off-by: Thierry Bultel Link: https://lore.kernel.org/r/20250403212919.1137670-8-thierry.bultel.yh@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12Z

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

serial: sh-sci: Save and restore more registers

2025-03-20T15:10:15Z

On (H)SCIF with a Baud Rate Generator for External Clock (BRG), there are multiple ways to configure the requested serial speed. If firmware uses a different method than Linux, and if any debug info is printed after the Bit Rate Register (SCBRR) is restored, but before termios is reconfigured (which configures the alternative method), the system may lock-up during resume. Fix this by saving and restoring the contents of the BRG Frequency Division (SCDL) and Clock Select (SCCKS) registers as well. Also save and restore the HSCIF's Sampling Rate Register (HSSRR), which configures the sampling point, and the SCIFA/SCIFB's Serial Port Control and Data Registers (SCPCR/SCPDR), which configure the optional control flow signals. After this, all registers that are not saved/restored are either: - read-only, - write-only, - status registers containing flags with clear-after-set semantics, - FIFO Data Count Trigger registers, which do not matter much for the serial console. Fixes: 22a6984c5b5df8ea ("serial: sh-sci: Update the suspend/resume support") Signed-off-by: Geert Uytterhoeven Tested-by: Claudiu Beznea Reviewed-by: Claudiu Beznea Link: https://lore.kernel.org/r/11c2eab45d48211e75d8b8202cce60400880fe55.1741114989.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Switch to use hrtimer_setup()

2025-02-20T14:38:33Z

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Acked-by: Zack Rusin Signed-off-by: Nam Cao Cc: Greg Kroah-Hartman Link: https://lore.kernel.org/r/c21664d013015584aebbb6bb8cedd748182cb551.1738746904.git.namcao@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

2025-02-19T14:08:36Z

The following splat has been observed on a SAMA5D27 platform using atmel_serial: BUG: sleeping function called from invalid context at kernel/irq/manage.c:738 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0 preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<00000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec softirqs last enabled at (0): [] copy_process+0x1ca0/0x7bec softirqs last disabled at (0): [<00000000>] 0x0 CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74 Hardware name: Atmel SAMA5 Workqueue: hci0 hci_power_on [bluetooth] Call trace: unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x44/0x70 dump_stack_lvl from __might_resched+0x38c/0x598 __might_resched from disable_irq+0x1c/0x48 disable_irq from mctrl_gpio_disable_ms+0x74/0xc0 mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4 atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8 atmel_set_termios from uart_change_line_settings+0x15c/0x994 uart_change_line_settings from uart_set_termios+0x2b0/0x668 uart_set_termios from tty_set_termios+0x600/0x8ec tty_set_termios from ttyport_set_flow_control+0x188/0x1e0 ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc] wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth] hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth] hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth] hci_power_on [bluetooth] from process_one_work+0x998/0x1a38 process_one_work from worker_thread+0x6e0/0xfb4 worker_thread from kthread+0x3d4/0x484 kthread from ret_from_fork+0x14/0x28 This warning is emitted when trying to toggle, at the highest level, some flow control (with serdev_device_set_flow_control) in a device driver. At the lowest level, the atmel_serial driver is using serial_mctrl_gpio lib to enable/disable the corresponding IRQs accordingly. The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to disable_irq (called in mctrl_gpio_disable_ms) being possibly called in some atomic context (some tty drivers perform modem lines configuration in regions protected by port lock). Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one and a blocking one. Replace mctrl_gpio_disable_ms calls with the relevant version depending on whether the call is protected by some port lock. Suggested-by: Jiri Slaby Signed-off-by: Alexis Lothoré Acked-by: Richard Genoud Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Update the suspend/resume support

2025-02-14T09:05:33Z

The Renesas RZ/G3S supports a power saving mode where power to most of the SoC components is turned off. When returning from this power saving mode, SoC components need to be re-configured. The SCIFs on the Renesas RZ/G3S need to be re-configured as well when returning from this power saving mode. The sh-sci code already configures the SCIF clocks, power domain and registers by calling uart_resume_port() in sci_resume(). On suspend path the SCIF UART ports are suspended accordingly (by calling uart_suspend_port() in sci_suspend()). The only missing setting is the reset signal. For this assert/de-assert the reset signal on driver suspend/resume. In case the no_console_suspend is specified by the user, the registers need to be saved on suspend path and restore on resume path. To do this the sci_console_save()/sci_console_restore() functions were added. There is no need to cache/restore the status or FIFO registers. Only the control registers. The registers that will be saved/restored on suspend/resume are specified by the struct sci_suspend_regs data structure. Signed-off-by: Claudiu Beznea Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20250207113313.545432-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Increment the runtime usage counter for the earlycon device

2025-01-17T11:54:37Z

In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman