diff options
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 98 |
1 files changed, 76 insertions, 22 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 924b803af440..b72c3bc19bfa 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -165,6 +165,8 @@ struct sci_port { static struct sci_port sci_ports[SCI_NPORTS]; static unsigned long sci_ports_in_use; static struct uart_driver sci_uart_driver; +static bool sci_uart_earlycon; +static bool sci_uart_earlycon_dev_probing; static inline struct sci_port * to_sci_port(struct uart_port *uart) @@ -1700,8 +1702,7 @@ static void sci_request_dma(struct uart_port *port) dma += s->buf_len_rx; } - hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - s->rx_timer.function = sci_dma_rx_timer_fn; + hrtimer_setup(&s->rx_timer, sci_dma_rx_timer_fn, CLOCK_MONOTONIC, HRTIMER_MODE_REL); s->chan_rx_saved = s->chan_rx = chan; @@ -3056,10 +3057,6 @@ static int sci_init_single(struct platform_device *dev, ret = sci_init_clocks(sci_port, &dev->dev); if (ret < 0) return ret; - - port->dev = &dev->dev; - - pm_runtime_enable(&dev->dev); } port->type = p->type; @@ -3086,11 +3083,6 @@ static int sci_init_single(struct platform_device *dev, return 0; } -static void sci_cleanup_single(struct sci_port *port) -{ - pm_runtime_disable(port->port.dev); -} - #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \ defined(CONFIG_SERIAL_SH_SCI_EARLYCON) static void serial_console_putchar(struct uart_port *port, unsigned char ch) @@ -3260,8 +3252,6 @@ static void sci_remove(struct platform_device *dev) sci_ports_in_use &= ~BIT(port->port.line); uart_remove_one_port(&sci_uart_driver, &port->port); - sci_cleanup_single(port); - if (port->port.fifosize > 1) device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger); if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF) @@ -3396,7 +3386,8 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, static int sci_probe_single(struct platform_device *dev, unsigned int index, struct plat_sci_port *p, - struct sci_port *sciport) + struct sci_port *sciport, + struct resource *sci_res) { int ret; @@ -3425,6 +3416,11 @@ static int sci_probe_single(struct platform_device *dev, if (ret) return ret; + sciport->port.dev = &dev->dev; + ret = devm_pm_runtime_enable(&dev->dev); + if (ret) + return ret; + sciport->gpios = mctrl_gpio_init(&sciport->port, 0); if (IS_ERR(sciport->gpios)) return PTR_ERR(sciport->gpios); @@ -3438,18 +3434,37 @@ static int sci_probe_single(struct platform_device *dev, sciport->port.flags |= UPF_HARD_FLOW; } - ret = uart_add_one_port(&sci_uart_driver, &sciport->port); - if (ret) { - sci_cleanup_single(sciport); - return ret; + if (sci_uart_earlycon && sci_ports[0].port.mapbase == sci_res->start) { + /* + * In case: + * - this is the earlycon port (mapped on index 0 in sci_ports[]) and + * - it now maps to an alias other than zero and + * - the earlycon is still alive (e.g., "earlycon keep_bootcon" is + * available in bootargs) + * + * we need to avoid disabling clocks and PM domains through the runtime + * PM APIs called in __device_attach(). For this, increment the runtime + * PM reference counter (the clocks and PM domains were already enabled + * by the bootloader). Otherwise the earlycon may access the HW when it + * has no clocks enabled leading to failures (infinite loop in + * sci_poll_put_char()). + */ + pm_runtime_get_noresume(&dev->dev); + + /* + * Skip cleanup the sci_port[0] in early_console_exit(), this + * port is the same as the earlycon one. + */ + sci_uart_earlycon_dev_probing = true; } - return 0; + return uart_add_one_port(&sci_uart_driver, &sciport->port); } static int sci_probe(struct platform_device *dev) { struct plat_sci_port *p; + struct resource *res; struct sci_port *sp; unsigned int dev_id; int ret; @@ -3479,9 +3494,29 @@ static int sci_probe(struct platform_device *dev) } sp = &sci_ports[dev_id]; + + /* + * In case: + * - the probed port alias is zero (as the one used by earlycon), and + * - the earlycon is still active (e.g., "earlycon keep_bootcon" in + * bootargs) + * + * defer the probe of this serial. This is a debug scenario and the user + * must be aware of it. + * + * Except when the probed port is the same as the earlycon port. + */ + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + if (sci_uart_earlycon && sp == &sci_ports[0] && sp->port.mapbase != res->start) + return dev_err_probe(&dev->dev, -EBUSY, "sci_port[0] is used by earlycon!\n"); + platform_set_drvdata(dev, sp); - ret = sci_probe_single(dev, dev_id, p, sp); + ret = sci_probe_single(dev, dev_id, p, sp, res); if (ret) return ret; @@ -3562,7 +3597,23 @@ sh_early_platform_init_buffer("earlyprintk", &sci_driver, early_serial_buf, ARRAY_SIZE(early_serial_buf)); #endif #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON -static struct plat_sci_port port_cfg __initdata; +static struct plat_sci_port port_cfg; + +static int early_console_exit(struct console *co) +{ + struct sci_port *sci_port = &sci_ports[0]; + + /* + * Clean the slot used by earlycon. A new SCI device might + * map to this slot. + */ + if (!sci_uart_earlycon_dev_probing) { + memset(sci_port, 0, sizeof(*sci_port)); + sci_uart_earlycon = false; + } + + return 0; +} static int __init early_console_setup(struct earlycon_device *device, int type) @@ -3571,15 +3622,18 @@ static int __init early_console_setup(struct earlycon_device *device, return -ENODEV; device->port.type = type; - memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port)); + sci_ports[0].port = device->port; port_cfg.type = type; sci_ports[0].cfg = &port_cfg; sci_ports[0].params = sci_probe_regmap(&port_cfg); + sci_uart_earlycon = true; port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR); sci_serial_out(&sci_ports[0].port, SCSCR, SCSCR_RE | SCSCR_TE | port_cfg.scscr); device->con->write = serial_console_write; + device->con->exit = early_console_exit; + return 0; } static int __init sci_early_console_setup(struct earlycon_device *device, |