diff options
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 1192 |
1 files changed, 628 insertions, 564 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 1b2f894bd..51c7507b0 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -84,6 +84,7 @@ struct sci_port { unsigned int overrun_reg; unsigned int overrun_mask; unsigned int error_mask; + unsigned int error_clear; unsigned int sampling_rate; resource_size_t reg_size; @@ -103,19 +104,15 @@ struct sci_port { struct dma_chan *chan_rx; #ifdef CONFIG_SERIAL_SH_SCI_DMA - struct dma_async_tx_descriptor *desc_tx; - struct dma_async_tx_descriptor *desc_rx[2]; dma_cookie_t cookie_tx; dma_cookie_t cookie_rx[2]; dma_cookie_t active_rx; - struct scatterlist sg_tx; - unsigned int sg_len_tx; + dma_addr_t tx_dma_addr; + unsigned int tx_dma_len; struct scatterlist sg_rx[2]; + void *rx_buf[2]; size_t buf_len_rx; - struct sh_dmae_slave param_tx; - struct sh_dmae_slave param_rx; struct work_struct work_tx; - struct work_struct work_rx; struct timer_list rx_timer; unsigned int rx_timeout; #endif @@ -123,11 +120,6 @@ struct sci_port { struct notifier_block freq_transition; }; -/* Function prototypes */ -static void sci_start_tx(struct uart_port *port); -static void sci_stop_tx(struct uart_port *port); -static void sci_start_rx(struct uart_port *port); - #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS static struct sci_port sci_ports[SCI_NPORTS]; @@ -146,7 +138,7 @@ struct plat_sci_reg { /* Helper for invalidating specific entries of an inherited map. */ #define sci_reg_invalid { .offset = 0, .size = 0 } -static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = { +static const struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = { [SCIx_PROBE_REGTYPE] = { [0 ... SCIx_NR_REGS - 1] = sci_reg_invalid, }, @@ -399,7 +391,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = { */ static unsigned int sci_serial_in(struct uart_port *p, int offset) { - struct plat_sci_reg *reg = sci_getreg(p, offset); + const struct plat_sci_reg *reg = sci_getreg(p, offset); if (reg->size == 8) return ioread8(p->membase + (reg->offset << p->regshift)); @@ -413,7 +405,7 @@ static unsigned int sci_serial_in(struct uart_port *p, int offset) static void sci_serial_out(struct uart_port *p, int offset, int value) { - struct plat_sci_reg *reg = sci_getreg(p, offset); + const struct plat_sci_reg *reg = sci_getreg(p, offset); if (reg->size == 8) iowrite8(value, p->membase + (reg->offset << p->regshift)); @@ -489,6 +481,105 @@ static void sci_port_disable(struct sci_port *sci_port) pm_runtime_put_sync(sci_port->port.dev); } +static inline unsigned long port_rx_irq_mask(struct uart_port *port) +{ + /* + * Not all ports (such as SCIFA) will support REIE. Rather than + * special-casing the port type, we check the port initialization + * IRQ enable mask to see whether the IRQ is desired at all. If + * it's unset, it's logically inferred that there's no point in + * testing for it. + */ + return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE); +} + +static void sci_start_tx(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + unsigned short ctrl; + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 new, scr = serial_port_in(port, SCSCR); + if (s->chan_tx) + new = scr | SCSCR_TDRQE; + else + new = scr & ~SCSCR_TDRQE; + if (new != scr) + serial_port_out(port, SCSCR, new); + } + + if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) && + dma_submit_error(s->cookie_tx)) { + s->cookie_tx = 0; + schedule_work(&s->work_tx); + } +#endif + + if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */ + ctrl = serial_port_in(port, SCSCR); + serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); + } +} + +static void sci_stop_tx(struct uart_port *port) +{ + unsigned short ctrl; + + /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */ + ctrl = serial_port_in(port, SCSCR); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_TDRQE; + + ctrl &= ~SCSCR_TIE; + + serial_port_out(port, SCSCR, ctrl); +} + +static void sci_start_rx(struct uart_port *port) +{ + unsigned short ctrl; + + ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_RDRQE; + + serial_port_out(port, SCSCR, ctrl); +} + +static void sci_stop_rx(struct uart_port *port) +{ + unsigned short ctrl; + + ctrl = serial_port_in(port, SCSCR); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + ctrl &= ~SCSCR_RDRQE; + + ctrl &= ~port_rx_irq_mask(port); + + serial_port_out(port, SCSCR, ctrl); +} + +static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask) +{ + if (port->type == PORT_SCI) { + /* Just store the mask */ + serial_port_out(port, SCxSR, mask); + } else if (to_sci_port(port)->overrun_mask == SCIFA_ORER) { + /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */ + /* Only clear the status bits we want to clear */ + serial_port_out(port, SCxSR, + serial_port_in(port, SCxSR) & mask); + } else { + /* Store the mask, clear parity/framing errors */ + serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC)); + } +} + #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) #ifdef CONFIG_CONSOLE_POLL @@ -500,7 +591,7 @@ static int sci_poll_get_char(struct uart_port *port) do { status = serial_port_in(port, SCxSR); if (status & SCxSR_ERRORS(port)) { - serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); continue; } break; @@ -513,7 +604,7 @@ static int sci_poll_get_char(struct uart_port *port) /* Dummy read */ serial_port_in(port, SCxSR); - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); return c; } @@ -528,14 +619,14 @@ static void sci_poll_put_char(struct uart_port *port, unsigned char c) } while (!(status & SCxSR_TDxE(port))); serial_port_out(port, SCxTDR, c); - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); } #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */ static void sci_init_pins(struct uart_port *port, unsigned int cflag) { struct sci_port *s = to_sci_port(port); - struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; + const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; /* * Use port-specific handler if provided. @@ -565,7 +656,7 @@ static void sci_init_pins(struct uart_port *port, unsigned int cflag) static int sci_txfill(struct uart_port *port) { - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; reg = sci_getreg(port, SCTFDR); if (reg->size) @@ -585,7 +676,7 @@ static int sci_txroom(struct uart_port *port) static int sci_rxfill(struct uart_port *port) { - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; reg = sci_getreg(port, SCRFDR); if (reg->size) @@ -655,7 +746,7 @@ static void sci_transmit_chars(struct uart_port *port) port->icount.tx++; } while (--count > 0); - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port)); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); @@ -666,7 +757,7 @@ static void sci_transmit_chars(struct uart_port *port) if (port->type != PORT_SCI) { serial_port_in(port, SCxSR); /* Dummy read */ - serial_port_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port)); } ctrl |= SCSCR_TIE; @@ -750,7 +841,7 @@ static void sci_receive_chars(struct uart_port *port) } serial_port_in(port, SCxSR); /* dummy read */ - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); copied += count; port->icount.rx += count; @@ -761,7 +852,7 @@ static void sci_receive_chars(struct uart_port *port) tty_flip_buffer_push(tport); } else { serial_port_in(port, SCxSR); /* dummy read */ - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); } } @@ -866,7 +957,7 @@ static int sci_handle_fifo_overrun(struct uart_port *port) { struct tty_port *tport = &port->state->port; struct sci_port *s = to_sci_port(port); - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; int copied = 0; u16 status; @@ -924,6 +1015,460 @@ static int sci_handle_breaks(struct uart_port *port) return copied; } +#ifdef CONFIG_SERIAL_SH_SCI_DMA +static void sci_dma_tx_complete(void *arg) +{ + struct sci_port *s = arg; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + + dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + + spin_lock_irqsave(&port->lock, flags); + + xmit->tail += s->tx_dma_len; + xmit->tail &= UART_XMIT_SIZE - 1; + + port->icount.tx += s->tx_dma_len; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (!uart_circ_empty(xmit)) { + s->cookie_tx = 0; + schedule_work(&s->work_tx); + } else { + s->cookie_tx = -EINVAL; + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 ctrl = serial_port_in(port, SCSCR); + serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE); + } + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +/* Locking: called with port lock held */ +static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count) +{ + struct uart_port *port = &s->port; + struct tty_port *tport = &port->state->port; + int copied; + + copied = tty_insert_flip_string(tport, buf, count); + if (copied < count) { + dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n", + count - copied); + port->icount.buf_overrun++; + } + + port->icount.rx += copied; + + return copied; +} + +static int sci_dma_rx_find_active(struct sci_port *s) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++) + if (s->active_rx == s->cookie_rx[i]) + return i; + + dev_err(s->port.dev, "%s: Rx cookie %d not found!\n", __func__, + s->active_rx); + return -1; +} + +static void sci_rx_dma_release(struct sci_port *s, bool enable_pio) +{ + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + s->chan_rx = NULL; + s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL; + spin_unlock_irqrestore(&port->lock, flags); + dmaengine_terminate_all(chan); + dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0], + sg_dma_address(&s->sg_rx[0])); + dma_release_channel(chan); + if (enable_pio) + sci_start_rx(port); +} + +static void sci_dma_rx_complete(void *arg) +{ + struct sci_port *s = arg; + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + struct dma_async_tx_descriptor *desc; + unsigned long flags; + int active, count = 0; + + dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line, + s->active_rx); + + spin_lock_irqsave(&port->lock, flags); + + active = sci_dma_rx_find_active(s); + if (active >= 0) + count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx); + + mod_timer(&s->rx_timer, jiffies + s->rx_timeout); + + if (count) + tty_flip_buffer_push(&port->state->port); + + desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + goto fail; + + desc->callback = sci_dma_rx_complete; + desc->callback_param = s; + s->cookie_rx[active] = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_rx[active])) + goto fail; + + s->active_rx = s->cookie_rx[!active]; + + dma_async_issue_pending(chan); + + dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n", + __func__, s->cookie_rx[active], active, s->active_rx); + spin_unlock_irqrestore(&port->lock, flags); + return; + +fail: + spin_unlock_irqrestore(&port->lock, flags); + dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); + sci_rx_dma_release(s, true); +} + +static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) +{ + struct dma_chan *chan = s->chan_tx; + struct uart_port *port = &s->port; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + s->chan_tx = NULL; + s->cookie_tx = -EINVAL; + spin_unlock_irqrestore(&port->lock, flags); + dmaengine_terminate_all(chan); + dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE, + DMA_TO_DEVICE); + dma_release_channel(chan); + if (enable_pio) + sci_start_tx(port); +} + +static void sci_submit_rx(struct sci_port *s) +{ + struct dma_chan *chan = s->chan_rx; + int i; + + for (i = 0; i < 2; i++) { + struct scatterlist *sg = &s->sg_rx[i]; + struct dma_async_tx_descriptor *desc; + + desc = dmaengine_prep_slave_sg(chan, + sg, 1, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + goto fail; + + desc->callback = sci_dma_rx_complete; + desc->callback_param = s; + s->cookie_rx[i] = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_rx[i])) + goto fail; + + dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__, + s->cookie_rx[i], i); + } + + s->active_rx = s->cookie_rx[0]; + + dma_async_issue_pending(chan); + return; + +fail: + if (i) + dmaengine_terminate_all(chan); + for (i = 0; i < 2; i++) + s->cookie_rx[i] = -EINVAL; + s->active_rx = -EINVAL; + dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n"); + sci_rx_dma_release(s, true); +} + +static void work_fn_tx(struct work_struct *work) +{ + struct sci_port *s = container_of(work, struct sci_port, work_tx); + struct dma_async_tx_descriptor *desc; + struct dma_chan *chan = s->chan_tx; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + dma_addr_t buf; + + /* + * DMA is idle now. + * Port xmit buffer is already mapped, and it is one page... Just adjust + * offsets and lengths. Since it is a circular buffer, we have to + * transmit till the end, and then the rest. Take the port lock to get a + * consistent xmit buffer state. + */ + spin_lock_irq(&port->lock); + buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1)); + s->tx_dma_len = min_t(unsigned int, + CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE), + CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE)); + spin_unlock_irq(&port->lock); + + desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n"); + /* switch to PIO */ + sci_tx_dma_release(s, true); + return; + } + + dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len, + DMA_TO_DEVICE); + + spin_lock_irq(&port->lock); + desc->callback = sci_dma_tx_complete; + desc->callback_param = s; + spin_unlock_irq(&port->lock); + s->cookie_tx = dmaengine_submit(desc); + if (dma_submit_error(s->cookie_tx)) { + dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n"); + /* switch to PIO */ + sci_tx_dma_release(s, true); + return; + } + + dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", + __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx); + + dma_async_issue_pending(chan); +} + +static void rx_timer_fn(unsigned long arg) +{ + struct sci_port *s = (struct sci_port *)arg; + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + struct dma_tx_state state; + enum dma_status status; + unsigned long flags; + unsigned int read; + int active, count; + u16 scr; + + spin_lock_irqsave(&port->lock, flags); + + dev_dbg(port->dev, "DMA Rx timed out\n"); + + active = sci_dma_rx_find_active(s); + if (active < 0) { + spin_unlock_irqrestore(&port->lock, flags); + return; + } + + status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); + if (status == DMA_COMPLETE) { + dev_dbg(port->dev, "Cookie %d #%d has already completed\n", + s->active_rx, active); + spin_unlock_irqrestore(&port->lock, flags); + + /* Let packet complete handler take care of the packet */ + return; + } + + dmaengine_pause(chan); + + /* + * sometimes DMA transfer doesn't stop even if it is stopped and + * data keeps on coming until transaction is complete so check + * for DMA_COMPLETE again + * Let packet complete handler take care of the packet + */ + status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); + if (status == DMA_COMPLETE) { + spin_unlock_irqrestore(&port->lock, flags); + dev_dbg(port->dev, "Transaction complete after DMA engine was stopped"); + return; + } + + /* Handle incomplete DMA receive */ + dmaengine_terminate_all(s->chan_rx); + read = sg_dma_len(&s->sg_rx[active]) - state.residue; + dev_dbg(port->dev, "Read %u bytes with cookie %d\n", read, + s->active_rx); + + if (read) { + count = sci_dma_rx_push(s, s->rx_buf[active], read); + if (count) + tty_flip_buffer_push(&port->state->port); + } + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + sci_submit_rx(s); + + /* Direct new serial port interrupts back to CPU */ + scr = serial_port_in(port, SCSCR); + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + scr &= ~SCSCR_RDRQE; + enable_irq(s->irqs[SCIx_RXI_IRQ]); + } + serial_port_out(port, SCSCR, scr | SCSCR_RIE); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static struct dma_chan *sci_request_dma_chan(struct uart_port *port, + enum dma_transfer_direction dir, + unsigned int id) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + struct dma_slave_config cfg; + int ret; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_slave_channel_compat(mask, shdma_chan_filter, + (void *)(unsigned long)id, port->dev, + dir == DMA_MEM_TO_DEV ? "tx" : "rx"); + if (!chan) { + dev_warn(port->dev, + "dma_request_slave_channel_compat failed\n"); + return NULL; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = port->mapbase + + (sci_getreg(port, SCxTDR)->offset << port->regshift); + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } else { + cfg.src_addr = port->mapbase + + (sci_getreg(port, SCxRDR)->offset << port->regshift); + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret); + dma_release_channel(chan); + return NULL; + } + + return chan; +} + +static void sci_request_dma(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + struct dma_chan *chan; + + dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); + + if (!port->dev->of_node && + (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0)) + return; + + s->cookie_tx = -EINVAL; + chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV, s->cfg->dma_slave_tx); + dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan); + if (chan) { + s->chan_tx = chan; + /* UART circular tx buffer is an aligned page. */ + s->tx_dma_addr = dma_map_single(chan->device->dev, + port->state->xmit.buf, + UART_XMIT_SIZE, + DMA_TO_DEVICE); + if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) { + dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n"); + dma_release_channel(chan); + s->chan_tx = NULL; + } else { + dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n", + __func__, UART_XMIT_SIZE, + port->state->xmit.buf, &s->tx_dma_addr); + } + + INIT_WORK(&s->work_tx, work_fn_tx); + } + + chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM, s->cfg->dma_slave_rx); + dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan); + if (chan) { + unsigned int i; + dma_addr_t dma; + void *buf; + + s->chan_rx = chan; + + s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize); + buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2, + &dma, GFP_KERNEL); + if (!buf) { + dev_warn(port->dev, + "Failed to allocate Rx dma buffer, using PIO\n"); + dma_release_channel(chan); + s->chan_rx = NULL; + return; + } + + for (i = 0; i < 2; i++) { + struct scatterlist *sg = &s->sg_rx[i]; + + sg_init_table(sg, 1); + s->rx_buf[i] = buf; + sg_dma_address(sg) = dma; + sg_dma_len(sg) = s->buf_len_rx; + + buf += s->buf_len_rx; + dma += s->buf_len_rx; + } + + setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s); + + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) + sci_submit_rx(s); + } +} + +static void sci_free_dma(struct uart_port *port) +{ + struct sci_port *s = to_sci_port(port); + + if (s->chan_tx) + sci_tx_dma_release(s, false); + if (s->chan_rx) + sci_rx_dma_release(s, false); +} +#else +static inline void sci_request_dma(struct uart_port *port) +{ +} + +static inline void sci_free_dma(struct uart_port *port) +{ +} +#endif + static irqreturn_t sci_rx_interrupt(int irq, void *ptr) { #ifdef CONFIG_SERIAL_SH_SCI_DMA @@ -940,10 +1485,12 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) scr |= SCSCR_RDRQE; } else { scr &= ~SCSCR_RIE; + sci_submit_rx(s); } serial_port_out(port, SCSCR, scr); /* Clear current interrupt */ - serial_port_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port))); + serial_port_out(port, SCxSR, + ssr & ~(SCIF_DR | SCxSR_RDxF(port))); dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n", jiffies, s->rx_timeout); mod_timer(&s->rx_timer, jiffies + s->rx_timeout); @@ -976,23 +1523,26 @@ static irqreturn_t sci_tx_interrupt(int irq, void *ptr) static irqreturn_t sci_er_interrupt(int irq, void *ptr) { struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); /* Handle errors */ if (port->type == PORT_SCI) { if (sci_handle_errors(port)) { /* discard character in rx buffer */ serial_port_in(port, SCxSR); - serial_port_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port)); } } else { sci_handle_fifo_overrun(port); - sci_rx_interrupt(irq, ptr); + if (!s->chan_rx) + sci_receive_chars(ptr); } - serial_port_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port)); /* Kick the transmission */ - sci_tx_interrupt(irq, ptr); + if (!s->chan_tx) + sci_tx_interrupt(irq, ptr); return IRQ_HANDLED; } @@ -1003,23 +1553,11 @@ static irqreturn_t sci_br_interrupt(int irq, void *ptr) /* Handle BREAKs */ sci_handle_breaks(port); - serial_port_out(port, SCxSR, SCxSR_BREAK_CLEAR(port)); + sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port)); return IRQ_HANDLED; } -static inline unsigned long port_rx_irq_mask(struct uart_port *port) -{ - /* - * Not all ports (such as SCIFA) will support REIE. Rather than - * special-casing the port type, we check the port initialization - * IRQ enable mask to see whether the IRQ is desired at all. If - * it's unset, it's logically inferred that there's no point in - * testing for it. - */ - return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE); -} - static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) { unsigned short ssr_status, scr_status, err_enabled, orer_status = 0; @@ -1048,11 +1586,8 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) * DR flags */ if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) && - (scr_status & SCSCR_RIE)) { - if (port->type == PORT_SCIF || port->type == PORT_HSCIF) - sci_handle_fifo_overrun(port); + (scr_status & SCSCR_RIE)) ret = sci_rx_interrupt(irq, ptr); - } /* Error Interrupt */ if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled) @@ -1063,8 +1598,10 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) ret = sci_br_interrupt(irq, ptr); /* Overrun Interrupt */ - if (orer_status & s->overrun_mask) + if (orer_status & s->overrun_mask) { sci_handle_fifo_overrun(port); + ret = IRQ_HANDLED; + } return ret; } @@ -1092,7 +1629,7 @@ static int sci_notifier(struct notifier_block *self, return NOTIFY_OK; } -static struct sci_irq_desc { +static const struct sci_irq_desc { const char *desc; irq_handler_t handler; } sci_irq_desc[] = { @@ -1134,7 +1671,7 @@ static int sci_request_irq(struct sci_port *port) int i, j, ret = 0; for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) { - struct sci_irq_desc *desc; + const struct sci_irq_desc *desc; int irq; if (SCIx_IRQ_IS_MUXED(port)) { @@ -1154,11 +1691,8 @@ static int sci_request_irq(struct sci_port *port) desc = sci_irq_desc + i; port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s", dev_name(up->dev), desc->desc); - if (!port->irqstr[j]) { - dev_err(up->dev, "Failed to allocate %s IRQ string\n", - desc->desc); + if (!port->irqstr[j]) goto out_nomem; - } ret = request_irq(irq, desc->handler, up->irqflags, port->irqstr[j], port); @@ -1232,7 +1766,7 @@ static unsigned int sci_tx_empty(struct uart_port *port) static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) { if (mctrl & TIOCM_LOOP) { - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; /* * Standard loopback mode for SCFCR ports. @@ -1254,356 +1788,10 @@ static unsigned int sci_get_mctrl(struct uart_port *port) return TIOCM_DSR | TIOCM_CAR; } -#ifdef CONFIG_SERIAL_SH_SCI_DMA -static void sci_dma_tx_complete(void *arg) -{ - struct sci_port *s = arg; - struct uart_port *port = &s->port; - struct circ_buf *xmit = &port->state->xmit; - unsigned long flags; - - dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); - - spin_lock_irqsave(&port->lock, flags); - - xmit->tail += sg_dma_len(&s->sg_tx); - xmit->tail &= UART_XMIT_SIZE - 1; - - port->icount.tx += sg_dma_len(&s->sg_tx); - - async_tx_ack(s->desc_tx); - s->desc_tx = NULL; - - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) - uart_write_wakeup(port); - - if (!uart_circ_empty(xmit)) { - s->cookie_tx = 0; - schedule_work(&s->work_tx); - } else { - s->cookie_tx = -EINVAL; - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { - u16 ctrl = serial_port_in(port, SCSCR); - serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE); - } - } - - spin_unlock_irqrestore(&port->lock, flags); -} - -/* Locking: called with port lock held */ -static int sci_dma_rx_push(struct sci_port *s, size_t count) -{ - struct uart_port *port = &s->port; - struct tty_port *tport = &port->state->port; - int i, active, room; - - room = tty_buffer_request_room(tport, count); - - if (s->active_rx == s->cookie_rx[0]) { - active = 0; - } else if (s->active_rx == s->cookie_rx[1]) { - active = 1; - } else { - dev_err(port->dev, "cookie %d not found!\n", s->active_rx); - return 0; - } - - if (room < count) - dev_warn(port->dev, "Rx overrun: dropping %zu bytes\n", - count - room); - if (!room) - return room; - - for (i = 0; i < room; i++) - tty_insert_flip_char(tport, ((u8 *)sg_virt(&s->sg_rx[active]))[i], - TTY_NORMAL); - - port->icount.rx += room; - - return room; -} - -static void sci_dma_rx_complete(void *arg) -{ - struct sci_port *s = arg; - struct uart_port *port = &s->port; - unsigned long flags; - int count; - - dev_dbg(port->dev, "%s(%d) active #%d\n", - __func__, port->line, s->active_rx); - - spin_lock_irqsave(&port->lock, flags); - - count = sci_dma_rx_push(s, s->buf_len_rx); - - mod_timer(&s->rx_timer, jiffies + s->rx_timeout); - - spin_unlock_irqrestore(&port->lock, flags); - - if (count) - tty_flip_buffer_push(&port->state->port); - - schedule_work(&s->work_rx); -} - -static void sci_rx_dma_release(struct sci_port *s, bool enable_pio) -{ - struct dma_chan *chan = s->chan_rx; - struct uart_port *port = &s->port; - - s->chan_rx = NULL; - s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL; - dma_release_channel(chan); - if (sg_dma_address(&s->sg_rx[0])) - dma_free_coherent(port->dev, s->buf_len_rx * 2, - sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0])); - if (enable_pio) - sci_start_rx(port); -} - -static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) -{ - struct dma_chan *chan = s->chan_tx; - struct uart_port *port = &s->port; - - s->chan_tx = NULL; - s->cookie_tx = -EINVAL; - dma_release_channel(chan); - if (enable_pio) - sci_start_tx(port); -} - -static void sci_submit_rx(struct sci_port *s) -{ - struct dma_chan *chan = s->chan_rx; - int i; - - for (i = 0; i < 2; i++) { - struct scatterlist *sg = &s->sg_rx[i]; - struct dma_async_tx_descriptor *desc; - - desc = dmaengine_prep_slave_sg(chan, - sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); - - if (desc) { - s->desc_rx[i] = desc; - desc->callback = sci_dma_rx_complete; - desc->callback_param = s; - s->cookie_rx[i] = desc->tx_submit(desc); - } - - if (!desc || s->cookie_rx[i] < 0) { - if (i) { - async_tx_ack(s->desc_rx[0]); - s->cookie_rx[0] = -EINVAL; - } - if (desc) { - async_tx_ack(desc); - s->cookie_rx[i] = -EINVAL; - } - dev_warn(s->port.dev, - "failed to re-start DMA, using PIO\n"); - sci_rx_dma_release(s, true); - return; - } - dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", - __func__, s->cookie_rx[i], i); - } - - s->active_rx = s->cookie_rx[0]; - - dma_async_issue_pending(chan); -} - -static void work_fn_rx(struct work_struct *work) -{ - struct sci_port *s = container_of(work, struct sci_port, work_rx); - struct uart_port *port = &s->port; - struct dma_async_tx_descriptor *desc; - int new; - - if (s->active_rx == s->cookie_rx[0]) { - new = 0; - } else if (s->active_rx == s->cookie_rx[1]) { - new = 1; - } else { - dev_err(port->dev, "cookie %d not found!\n", s->active_rx); - return; - } - desc = s->desc_rx[new]; - - if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) != - DMA_COMPLETE) { - /* Handle incomplete DMA receive */ - struct dma_chan *chan = s->chan_rx; - struct shdma_desc *sh_desc = container_of(desc, - struct shdma_desc, async_tx); - unsigned long flags; - int count; - - dmaengine_terminate_all(chan); - dev_dbg(port->dev, "Read %zu bytes with cookie %d\n", - sh_desc->partial, sh_desc->cookie); - - spin_lock_irqsave(&port->lock, flags); - count = sci_dma_rx_push(s, sh_desc->partial); - spin_unlock_irqrestore(&port->lock, flags); - - if (count) - tty_flip_buffer_push(&port->state->port); - - sci_submit_rx(s); - - return; - } - - s->cookie_rx[new] = desc->tx_submit(desc); - if (s->cookie_rx[new] < 0) { - dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); - sci_rx_dma_release(s, true); - return; - } - - s->active_rx = s->cookie_rx[!new]; - - dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", - __func__, s->cookie_rx[new], new, s->active_rx); -} - -static void work_fn_tx(struct work_struct *work) -{ - struct sci_port *s = container_of(work, struct sci_port, work_tx); - struct dma_async_tx_descriptor *desc; - struct dma_chan *chan = s->chan_tx; - struct uart_port *port = &s->port; - struct circ_buf *xmit = &port->state->xmit; - struct scatterlist *sg = &s->sg_tx; - - /* - * DMA is idle now. - * Port xmit buffer is already mapped, and it is one page... Just adjust - * offsets and lengths. Since it is a circular buffer, we have to - * transmit till the end, and then the rest. Take the port lock to get a - * consistent xmit buffer state. - */ - spin_lock_irq(&port->lock); - sg->offset = xmit->tail & (UART_XMIT_SIZE - 1); - sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) + - sg->offset; - sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE), - CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE)); - spin_unlock_irq(&port->lock); - - BUG_ON(!sg_dma_len(sg)); - - desc = dmaengine_prep_slave_sg(chan, - sg, s->sg_len_tx, DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); - if (!desc) { - /* switch to PIO */ - sci_tx_dma_release(s, true); - return; - } - - dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE); - - spin_lock_irq(&port->lock); - s->desc_tx = desc; - desc->callback = sci_dma_tx_complete; - desc->callback_param = s; - spin_unlock_irq(&port->lock); - s->cookie_tx = desc->tx_submit(desc); - if (s->cookie_tx < 0) { - dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n"); - /* switch to PIO */ - sci_tx_dma_release(s, true); - return; - } - - dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", - __func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx); - - dma_async_issue_pending(chan); -} -#endif - -static void sci_start_tx(struct uart_port *port) -{ - struct sci_port *s = to_sci_port(port); - unsigned short ctrl; - -#ifdef CONFIG_SERIAL_SH_SCI_DMA - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { - u16 new, scr = serial_port_in(port, SCSCR); - if (s->chan_tx) - new = scr | SCSCR_TDRQE; - else - new = scr & ~SCSCR_TDRQE; - if (new != scr) - serial_port_out(port, SCSCR, new); - } - - if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) && - s->cookie_tx < 0) { - s->cookie_tx = 0; - schedule_work(&s->work_tx); - } -#endif - - if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) { - /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */ - ctrl = serial_port_in(port, SCSCR); - serial_port_out(port, SCSCR, ctrl | SCSCR_TIE); - } -} - -static void sci_stop_tx(struct uart_port *port) -{ - unsigned short ctrl; - - /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */ - ctrl = serial_port_in(port, SCSCR); - - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) - ctrl &= ~SCSCR_TDRQE; - - ctrl &= ~SCSCR_TIE; - - serial_port_out(port, SCSCR, ctrl); -} - -static void sci_start_rx(struct uart_port *port) -{ - unsigned short ctrl; - - ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port); - - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) - ctrl &= ~SCSCR_RDRQE; - - serial_port_out(port, SCSCR, ctrl); -} - -static void sci_stop_rx(struct uart_port *port) -{ - unsigned short ctrl; - - ctrl = serial_port_in(port, SCSCR); - - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) - ctrl &= ~SCSCR_RDRQE; - - ctrl &= ~port_rx_irq_mask(port); - - serial_port_out(port, SCSCR, ctrl); -} - static void sci_break_ctl(struct uart_port *port, int break_state) { struct sci_port *s = to_sci_port(port); - struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; + const struct plat_sci_reg *reg = sci_regmap[s->cfg->regtype] + SCSPTR; unsigned short scscr, scsptr; /* check wheter the port has SCSPTR */ @@ -1630,142 +1818,6 @@ static void sci_break_ctl(struct uart_port *port, int break_state) serial_port_out(port, SCSCR, scscr); } -#ifdef CONFIG_SERIAL_SH_SCI_DMA -static bool filter(struct dma_chan *chan, void *slave) -{ - struct sh_dmae_slave *param = slave; - - dev_dbg(chan->device->dev, "%s: slave ID %d\n", - __func__, param->shdma_slave.slave_id); - - chan->private = ¶m->shdma_slave; - return true; -} - -static void rx_timer_fn(unsigned long arg) -{ - struct sci_port *s = (struct sci_port *)arg; - struct uart_port *port = &s->port; - u16 scr = serial_port_in(port, SCSCR); - - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { - scr &= ~SCSCR_RDRQE; - enable_irq(s->irqs[SCIx_RXI_IRQ]); - } - serial_port_out(port, SCSCR, scr | SCSCR_RIE); - dev_dbg(port->dev, "DMA Rx timed out\n"); - schedule_work(&s->work_rx); -} - -static void sci_request_dma(struct uart_port *port) -{ - struct sci_port *s = to_sci_port(port); - struct sh_dmae_slave *param; - struct dma_chan *chan; - dma_cap_mask_t mask; - int nent; - - dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); - - if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0) - return; - - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - param = &s->param_tx; - - /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */ - param->shdma_slave.slave_id = s->cfg->dma_slave_tx; - - s->cookie_tx = -EINVAL; - chan = dma_request_channel(mask, filter, param); - dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan); - if (chan) { - s->chan_tx = chan; - sg_init_table(&s->sg_tx, 1); - /* UART circular tx buffer is an aligned page. */ - BUG_ON((uintptr_t)port->state->xmit.buf & ~PAGE_MASK); - sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf), - UART_XMIT_SIZE, - (uintptr_t)port->state->xmit.buf & ~PAGE_MASK); - nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE); - if (!nent) - sci_tx_dma_release(s, false); - else - dev_dbg(port->dev, "%s: mapped %d@%p to %pad\n", - __func__, - sg_dma_len(&s->sg_tx), port->state->xmit.buf, - &sg_dma_address(&s->sg_tx)); - - s->sg_len_tx = nent; - - INIT_WORK(&s->work_tx, work_fn_tx); - } - - param = &s->param_rx; - - /* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */ - param->shdma_slave.slave_id = s->cfg->dma_slave_rx; - - chan = dma_request_channel(mask, filter, param); - dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan); - if (chan) { - dma_addr_t dma[2]; - void *buf[2]; - int i; - - s->chan_rx = chan; - - s->buf_len_rx = 2 * max(16, (int)port->fifosize); - buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2, - &dma[0], GFP_KERNEL); - - if (!buf[0]) { - dev_warn(port->dev, - "failed to allocate dma buffer, using PIO\n"); - sci_rx_dma_release(s, true); - return; - } - - buf[1] = buf[0] + s->buf_len_rx; - dma[1] = dma[0] + s->buf_len_rx; - - for (i = 0; i < 2; i++) { - struct scatterlist *sg = &s->sg_rx[i]; - - sg_init_table(sg, 1); - sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx, - (uintptr_t)buf[i] & ~PAGE_MASK); - sg_dma_address(sg) = dma[i]; - } - - INIT_WORK(&s->work_rx, work_fn_rx); - setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s); - - sci_submit_rx(s); - } -} - -static void sci_free_dma(struct uart_port *port) -{ - struct sci_port *s = to_sci_port(port); - - if (s->chan_tx) - sci_tx_dma_release(s, false); - if (s->chan_rx) - sci_rx_dma_release(s, false); -} -#else -static inline void sci_request_dma(struct uart_port *port) -{ -} - -static inline void sci_free_dma(struct uart_port *port) -{ -} -#endif - static int sci_startup(struct uart_port *port) { struct sci_port *s = to_sci_port(port); @@ -1800,6 +1852,14 @@ static void sci_shutdown(struct uart_port *port) sci_stop_tx(port); spin_unlock_irqrestore(&port->lock, flags); +#ifdef CONFIG_SERIAL_SH_SCI_DMA + if (s->chan_rx) { + dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__, + port->line); + del_timer_sync(&s->rx_timer); + } +#endif + sci_free_dma(port); sci_free_irq(s); } @@ -1892,7 +1952,7 @@ static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq, static void sci_reset(struct uart_port *port) { - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; unsigned int status; do { @@ -1910,7 +1970,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct sci_port *s = to_sci_port(port); - struct plat_sci_reg *reg; + const struct plat_sci_reg *reg; unsigned int baud, smr_val = 0, max_baud, cks = 0; int t = -1; unsigned int srr = 15; @@ -1951,7 +2011,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, sci_reset(port); - smr_val |= serial_port_in(port, SCSMR) & 3; + smr_val |= serial_port_in(port, SCSMR) & SCSMR_CKS; uart_update_timeout(port, termios->c_cflag, baud); @@ -1996,13 +2056,13 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, #ifdef CONFIG_SERIAL_SH_SCI_DMA /* * Calculate delay for 2 DMA buffers (4 FIFO). - * See drivers/serial/serial_core.c::uart_update_timeout(). With 10 - * bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function - * calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)." - * Then below we calculate 5 jiffies (20ms) for 2 DMA buffers (4 FIFO - * sizes), but when performing a faster transfer, value obtained by - * this formula is may not enough. Therefore, if value is smaller than - * 20msec, this sets 20msec as timeout of DMA. + * See serial_core.c::uart_update_timeout(). + * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above + * function calculates 1 jiffie for the data plus 5 jiffies for the + * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA + * buffers (4 FIFO sizes), but when performing a faster transfer, the + * value obtained by this formula is too small. Therefore, if the value + * is smaller than 20ms, use 20ms as the timeout value for DMA. */ if (s->chan_rx) { unsigned int bits; @@ -2187,7 +2247,6 @@ static int sci_init_single(struct platform_device *dev, { struct uart_port *port = &sci_port->port; const struct resource *res; - unsigned int sampling_rate; unsigned int i; int ret; @@ -2232,37 +2291,37 @@ static int sci_init_single(struct platform_device *dev, port->fifosize = 256; sci_port->overrun_reg = SCxSR; sci_port->overrun_mask = SCIFA_ORER; - sampling_rate = 16; + sci_port->sampling_rate = 16; break; case PORT_HSCIF: port->fifosize = 128; - sampling_rate = 0; sci_port->overrun_reg = SCLSR; sci_port->overrun_mask = SCLSR_ORER; + sci_port->sampling_rate = 0; break; case PORT_SCIFA: port->fifosize = 64; sci_port->overrun_reg = SCxSR; sci_port->overrun_mask = SCIFA_ORER; - sampling_rate = 16; + sci_port->sampling_rate = 16; break; case PORT_SCIF: port->fifosize = 16; if (p->regtype == SCIx_SH7705_SCIF_REGTYPE) { sci_port->overrun_reg = SCxSR; sci_port->overrun_mask = SCIFA_ORER; - sampling_rate = 16; + sci_port->sampling_rate = 16; } else { sci_port->overrun_reg = SCLSR; sci_port->overrun_mask = SCLSR_ORER; - sampling_rate = 32; + sci_port->sampling_rate = 32; } break; default: port->fifosize = 1; sci_port->overrun_reg = SCxSR; sci_port->overrun_mask = SCI_ORER; - sampling_rate = 32; + sci_port->sampling_rate = 32; break; } @@ -2270,8 +2329,8 @@ static int sci_init_single(struct platform_device *dev, * match the SoC datasheet, this should be investigated. Let platform * data override the sampling rate for now. */ - sci_port->sampling_rate = p->sampling_rate ? p->sampling_rate - : sampling_rate; + if (p->sampling_rate) + sci_port->sampling_rate = p->sampling_rate; if (!early) { sci_port->iclk = clk_get(&dev->dev, "sci_ick"); @@ -2303,15 +2362,22 @@ static int sci_init_single(struct platform_device *dev, /* * Establish some sensible defaults for the error detection. */ - sci_port->error_mask = (p->type == PORT_SCI) ? - SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK; + if (p->type == PORT_SCI) { + sci_port->error_mask = SCI_DEFAULT_ERROR_MASK; + sci_port->error_clear = SCI_ERROR_CLEAR; + } else { + sci_port->error_mask = SCIF_DEFAULT_ERROR_MASK; + sci_port->error_clear = SCIF_ERROR_CLEAR; + } /* * Make the error mask inclusive of overrun detection, if * supported. */ - if (sci_port->overrun_reg == SCxSR) + if (sci_port->overrun_reg == SCxSR) { sci_port->error_mask |= sci_port->overrun_mask; + sci_port->error_clear &= ~sci_port->overrun_mask; + } port->type = p->type; port->flags = UPF_FIXED_PORT | p->flags; @@ -2564,10 +2630,8 @@ sci_parse_dt(struct platform_device *pdev, unsigned int *dev_id) info = match->data; p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL); - if (!p) { - dev_err(&pdev->dev, "failed to allocate DT config data\n"); + if (!p) return NULL; - } /* Get the line number for the aliases node. */ id = of_alias_get_id(np, "serial"); |