diff options
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 195 |
1 files changed, 174 insertions, 21 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 6182ae5f6fa1..f5c0ec4ea08f 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -105,6 +105,20 @@ struct plat_sci_reg { u8 offset, size; }; +struct sci_suspend_regs { + u16 scdl; + u16 sccks; + u16 scsmr; + u16 scscr; + u16 scfcr; + u16 scsptr; + u16 hssrr; + u16 scpcr; + u16 scpdr; + u8 scbrr; + u8 semr; +}; + struct sci_port_params { const struct plat_sci_reg regs[SCIx_NR_REGS]; unsigned int fifosize; @@ -135,6 +149,8 @@ struct sci_port { struct dma_chan *chan_tx; struct dma_chan *chan_rx; + struct reset_control *rstc; + #ifdef CONFIG_SERIAL_SH_SCI_DMA struct dma_chan *chan_tx_saved; struct dma_chan *chan_rx_saved; @@ -154,10 +170,12 @@ struct sci_port { int rx_trigger; struct timer_list rx_fifo_timer; int rx_fifo_timeout; + struct sci_suspend_regs suspend_regs; u16 hscif_tot; bool has_rtscts; bool autorts; + bool tx_occurred; }; #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS @@ -166,6 +184,7 @@ 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) @@ -808,6 +827,7 @@ static void sci_transmit_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; unsigned int stopped = uart_tx_stopped(port); + struct sci_port *s = to_sci_port(port); unsigned short status; unsigned short ctrl; int count; @@ -839,6 +859,7 @@ static void sci_transmit_chars(struct uart_port *port) } serial_port_out(port, SCxTDR, c); + s->tx_occurred = true; port->icount.tx++; } while (--count > 0); @@ -1191,6 +1212,8 @@ static void sci_dma_tx_complete(void *arg) if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); + s->tx_occurred = true; + if (!uart_circ_empty(xmit)) { s->cookie_tx = 0; schedule_work(&s->work_tx); @@ -1671,6 +1694,19 @@ static void sci_flush_buffer(struct uart_port *port) s->cookie_tx = -EINVAL; } } + +static void sci_dma_check_tx_occurred(struct sci_port *s) +{ + struct dma_tx_state state; + enum dma_status status; + + if (!s->chan_tx) + return; + + status = dmaengine_tx_status(s->chan_tx, s->cookie_tx, &state); + if (status == DMA_COMPLETE || status == DMA_IN_PROGRESS) + s->tx_occurred = true; +} #else /* !CONFIG_SERIAL_SH_SCI_DMA */ static inline void sci_request_dma(struct uart_port *port) { @@ -1680,6 +1716,10 @@ static inline void sci_free_dma(struct uart_port *port) { } +static void sci_dma_check_tx_occurred(struct sci_port *s) +{ +} + #define sci_flush_buffer NULL #endif /* !CONFIG_SERIAL_SH_SCI_DMA */ @@ -1992,6 +2032,12 @@ static unsigned int sci_tx_empty(struct uart_port *port) { unsigned short status = serial_port_in(port, SCxSR); unsigned short in_tx_fifo = sci_txfill(port); + struct sci_port *s = to_sci_port(port); + + sci_dma_check_tx_occurred(s); + + if (!s->tx_occurred) + return TIOCSER_TEMT; return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0; } @@ -2162,6 +2208,7 @@ static int sci_startup(struct uart_port *port) dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + s->tx_occurred = false; sci_request_dma(port); ret = sci_request_irq(s); @@ -2182,7 +2229,7 @@ static void sci_shutdown(struct uart_port *port) dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); s->autorts = false; - mctrl_gpio_disable_ms(to_sci_port(port)->gpios); + mctrl_gpio_disable_ms_sync(to_sci_port(port)->gpios); spin_lock_irqsave(&port->lock, flags); sci_stop_rx(port); @@ -2936,10 +2983,6 @@ 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; @@ -2969,11 +3012,6 @@ 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) @@ -3131,8 +3169,6 @@ static int 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) @@ -3252,6 +3288,7 @@ static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev, } sp = &sci_ports[id]; + sp->rstc = rstc; *dev_id = id; p->type = SCI_OF_TYPE(data); @@ -3265,7 +3302,8 @@ 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; @@ -3294,6 +3332,11 @@ 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); @@ -3307,13 +3350,31 @@ 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) @@ -3371,7 +3432,7 @@ static int sci_probe(struct platform_device *dev) 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; @@ -3400,13 +3461,77 @@ static int sci_probe(struct platform_device *dev) return 0; } +static void sci_console_save(struct sci_port *s) +{ + struct sci_suspend_regs *regs = &s->suspend_regs; + struct uart_port *port = &s->port; + + if (sci_getreg(port, SCDL)->size) + regs->scdl = sci_serial_in(port, SCDL); + if (sci_getreg(port, SCCKS)->size) + regs->sccks = sci_serial_in(port, SCCKS); + if (sci_getreg(port, SCSMR)->size) + regs->scsmr = sci_serial_in(port, SCSMR); + if (sci_getreg(port, SCSCR)->size) + regs->scscr = sci_serial_in(port, SCSCR); + if (sci_getreg(port, SCFCR)->size) + regs->scfcr = sci_serial_in(port, SCFCR); + if (sci_getreg(port, SCSPTR)->size) + regs->scsptr = sci_serial_in(port, SCSPTR); + if (sci_getreg(port, SCBRR)->size) + regs->scbrr = sci_serial_in(port, SCBRR); + if (sci_getreg(port, HSSRR)->size) + regs->hssrr = sci_serial_in(port, HSSRR); + if (sci_getreg(port, SCPCR)->size) + regs->scpcr = sci_serial_in(port, SCPCR); + if (sci_getreg(port, SCPDR)->size) + regs->scpdr = sci_serial_in(port, SCPDR); + if (sci_getreg(port, SEMR)->size) + regs->semr = sci_serial_in(port, SEMR); +} + +static void sci_console_restore(struct sci_port *s) +{ + struct sci_suspend_regs *regs = &s->suspend_regs; + struct uart_port *port = &s->port; + + if (sci_getreg(port, SCDL)->size) + sci_serial_out(port, SCDL, regs->scdl); + if (sci_getreg(port, SCCKS)->size) + sci_serial_out(port, SCCKS, regs->sccks); + if (sci_getreg(port, SCSMR)->size) + sci_serial_out(port, SCSMR, regs->scsmr); + if (sci_getreg(port, SCSCR)->size) + sci_serial_out(port, SCSCR, regs->scscr); + if (sci_getreg(port, SCFCR)->size) + sci_serial_out(port, SCFCR, regs->scfcr); + if (sci_getreg(port, SCSPTR)->size) + sci_serial_out(port, SCSPTR, regs->scsptr); + if (sci_getreg(port, SCBRR)->size) + sci_serial_out(port, SCBRR, regs->scbrr); + if (sci_getreg(port, HSSRR)->size) + sci_serial_out(port, HSSRR, regs->hssrr); + if (sci_getreg(port, SCPCR)->size) + sci_serial_out(port, SCPCR, regs->scpcr); + if (sci_getreg(port, SCPDR)->size) + sci_serial_out(port, SCPDR, regs->scpdr); + if (sci_getreg(port, SEMR)->size) + sci_serial_out(port, SEMR, regs->semr); +} + static __maybe_unused int sci_suspend(struct device *dev) { struct sci_port *sport = dev_get_drvdata(dev); - if (sport) + if (sport) { uart_suspend_port(&sci_uart_driver, &sport->port); + if (!console_suspend_enabled && uart_console(&sport->port)) + sci_console_save(sport); + else + return reset_control_assert(sport->rstc); + } + return 0; } @@ -3414,8 +3539,18 @@ static __maybe_unused int sci_resume(struct device *dev) { struct sci_port *sport = dev_get_drvdata(dev); - if (sport) + if (sport) { + if (!console_suspend_enabled && uart_console(&sport->port)) { + sci_console_restore(sport); + } else { + int ret = reset_control_deassert(sport->rstc); + + if (ret) + return ret; + } + uart_resume_port(&sci_uart_driver, &sport->port); + } return 0; } @@ -3454,6 +3589,22 @@ sh_early_platform_init_buffer("earlyprintk", &sci_driver, #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON 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) { @@ -3473,6 +3624,8 @@ static int __init early_console_setup(struct earlycon_device *device, 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, |