diff options
Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 1145 |
1 files changed, 961 insertions, 184 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index e76d7d00012..0e26dcbd5ea 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -1,6 +1,4 @@ /* - * linux/drivers/char/amba.c - * * Driver for AMBA serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. @@ -31,6 +29,7 @@ * and hooked into this driver. */ + #if defined(CONFIG_SERIAL_AMBA_PL011_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif @@ -52,9 +51,13 @@ #include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/scatterlist.h> - -#include <asm/io.h> -#include <asm/sizes.h> +#include <linux/delay.h> +#include <linux/types.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/pinctrl/consumer.h> +#include <linux/sizes.h> +#include <linux/io.h> #define UART_NR 14 @@ -70,32 +73,68 @@ /* There is by now at least one vendor with differing details, so handle it */ struct vendor_data { unsigned int ifls; - unsigned int fifosize; unsigned int lcrh_tx; unsigned int lcrh_rx; bool oversampling; bool dma_threshold; + bool cts_event_workaround; + + unsigned int (*get_fifosize)(struct amba_device *dev); }; +static unsigned int get_fifosize_arm(struct amba_device *dev) +{ + return amba_rev(dev) < 3 ? 16 : 32; +} + static struct vendor_data vendor_arm = { .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8, - .fifosize = 16, .lcrh_tx = UART011_LCRH, .lcrh_rx = UART011_LCRH, .oversampling = false, .dma_threshold = false, + .cts_event_workaround = false, + .get_fifosize = get_fifosize_arm, }; +static unsigned int get_fifosize_st(struct amba_device *dev) +{ + return 64; +} + static struct vendor_data vendor_st = { .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF, - .fifosize = 64, .lcrh_tx = ST_UART011_LCRH_TX, .lcrh_rx = ST_UART011_LCRH_RX, .oversampling = true, .dma_threshold = true, + .cts_event_workaround = true, + .get_fifosize = get_fifosize_st, }; /* Deals with DMA transactions */ + +struct pl011_sgbuf { + struct scatterlist sg; + char *buf; +}; + +struct pl011_dmarx_data { + struct dma_chan *chan; + struct completion complete; + bool use_buf_b; + struct pl011_sgbuf sgbuf_a; + struct pl011_sgbuf sgbuf_b; + dma_cookie_t cookie; + bool running; + struct timer_list timer; + unsigned int last_residue; + unsigned long last_jiffies; + bool auto_poll_rate; + unsigned int poll_rate; + unsigned int poll_timeout; +}; + struct pl011_dmatx_data { struct dma_chan *chan; struct scatterlist sg; @@ -116,16 +155,75 @@ struct uart_amba_port { unsigned int fifosize; /* vendor-specific */ unsigned int lcrh_tx; /* vendor-specific */ unsigned int lcrh_rx; /* vendor-specific */ + unsigned int old_cr; /* state during shutdown */ bool autorts; char type[12]; #ifdef CONFIG_DMA_ENGINE /* DMA stuff */ - bool using_dma; + bool using_tx_dma; + bool using_rx_dma; + struct pl011_dmarx_data dmarx; struct pl011_dmatx_data dmatx; #endif }; /* + * Reads up to 256 characters from the FIFO or until it's empty and + * inserts them into the TTY layer. Returns the number of characters + * read from the FIFO. + */ +static int pl011_fifo_to_tty(struct uart_amba_port *uap) +{ + u16 status, ch; + unsigned int flag, max_count = 256; + int fifotaken = 0; + + while (max_count--) { + status = readw(uap->port.membase + UART01x_FR); + if (status & UART01x_FR_RXFE) + break; + + /* Take chars from the FIFO and update status */ + ch = readw(uap->port.membase + UART01x_DR) | + UART_DUMMY_DR_RX; + flag = TTY_NORMAL; + uap->port.icount.rx++; + fifotaken++; + + if (unlikely(ch & UART_DR_ERROR)) { + if (ch & UART011_DR_BE) { + ch &= ~(UART011_DR_FE | UART011_DR_PE); + uap->port.icount.brk++; + if (uart_handle_break(&uap->port)) + continue; + } else if (ch & UART011_DR_PE) + uap->port.icount.parity++; + else if (ch & UART011_DR_FE) + uap->port.icount.frame++; + if (ch & UART011_DR_OE) + uap->port.icount.overrun++; + + ch &= uap->port.read_status_mask; + + if (ch & UART011_DR_BE) + flag = TTY_BREAK; + else if (ch & UART011_DR_PE) + flag = TTY_PARITY; + else if (ch & UART011_DR_FE) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(&uap->port, ch & 255)) + continue; + + uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); + } + + return fifotaken; +} + + +/* * All the DMA operation mode stuff goes inside this ifdef. * This assumes that you have a generic DMA device interface, * no custom DMA interfaces are supported. @@ -134,33 +232,67 @@ struct uart_amba_port { #define PL011_DMA_BUFFER_SIZE PAGE_SIZE -static void pl011_dma_probe_initcall(struct uart_amba_port *uap) +static int pl011_sgbuf_init(struct dma_chan *chan, struct pl011_sgbuf *sg, + enum dma_data_direction dir) +{ + dma_addr_t dma_addr; + + sg->buf = dma_alloc_coherent(chan->device->dev, + PL011_DMA_BUFFER_SIZE, &dma_addr, GFP_KERNEL); + if (!sg->buf) + return -ENOMEM; + + sg_init_table(&sg->sg, 1); + sg_set_page(&sg->sg, phys_to_page(dma_addr), + PL011_DMA_BUFFER_SIZE, offset_in_page(dma_addr)); + sg_dma_address(&sg->sg) = dma_addr; + + return 0; +} + +static void pl011_sgbuf_free(struct dma_chan *chan, struct pl011_sgbuf *sg, + enum dma_data_direction dir) +{ + if (sg->buf) { + dma_free_coherent(chan->device->dev, + PL011_DMA_BUFFER_SIZE, sg->buf, + sg_dma_address(&sg->sg)); + } +} + +static void pl011_dma_probe_initcall(struct device *dev, struct uart_amba_port *uap) { /* DMA is the sole user of the platform data right now */ - struct amba_pl011_data *plat = uap->port.dev->platform_data; + struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev); struct dma_slave_config tx_conf = { .dst_addr = uap->port.mapbase + UART01x_DR, .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, - .direction = DMA_TO_DEVICE, + .direction = DMA_MEM_TO_DEV, .dst_maxburst = uap->fifosize >> 1, + .device_fc = false, }; struct dma_chan *chan; dma_cap_mask_t mask; - /* We need platform data */ - if (!plat || !plat->dma_filter) { - dev_info(uap->port.dev, "no DMA platform data\n"); - return; - } + chan = dma_request_slave_channel(dev, "tx"); - /* Try to acquire a generic DMA engine slave channel */ - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param); if (!chan) { - dev_err(uap->port.dev, "no TX DMA channel!\n"); - return; + /* We need platform data */ + if (!plat || !plat->dma_filter) { + dev_info(uap->port.dev, "no DMA platform data\n"); + return; + } + + /* Try to acquire a generic DMA engine slave TX channel */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_channel(mask, plat->dma_filter, + plat->dma_tx_param); + if (!chan) { + dev_err(uap->port.dev, "no TX DMA channel!\n"); + return; + } } dmaengine_slave_config(chan, &tx_conf); @@ -168,6 +300,57 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) dev_info(uap->port.dev, "DMA channel TX %s\n", dma_chan_name(uap->dmatx.chan)); + + /* Optionally make use of an RX channel as well */ + chan = dma_request_slave_channel(dev, "rx"); + + if (!chan && plat->dma_rx_param) { + chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param); + + if (!chan) { + dev_err(uap->port.dev, "no RX DMA channel!\n"); + return; + } + } + + if (chan) { + struct dma_slave_config rx_conf = { + .src_addr = uap->port.mapbase + UART01x_DR, + .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, + .direction = DMA_DEV_TO_MEM, + .src_maxburst = uap->fifosize >> 2, + .device_fc = false, + }; + + dmaengine_slave_config(chan, &rx_conf); + uap->dmarx.chan = chan; + + if (plat && plat->dma_rx_poll_enable) { + /* Set poll rate if specified. */ + if (plat->dma_rx_poll_rate) { + uap->dmarx.auto_poll_rate = false; + uap->dmarx.poll_rate = plat->dma_rx_poll_rate; + } else { + /* + * 100 ms defaults to poll rate if not + * specified. This will be adjusted with + * the baud rate at set_termios. + */ + uap->dmarx.auto_poll_rate = true; + uap->dmarx.poll_rate = 100; + } + /* 3 secs defaults poll_timeout if not specified. */ + if (plat->dma_rx_poll_timeout) + uap->dmarx.poll_timeout = + plat->dma_rx_poll_timeout; + else + uap->dmarx.poll_timeout = 3000; + } else + uap->dmarx.auto_poll_rate = false; + + dev_info(uap->port.dev, "DMA channel RX %s\n", + dma_chan_name(uap->dmarx.chan)); + } } #ifndef MODULE @@ -180,6 +363,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap) struct dma_uap { struct list_head node; struct uart_amba_port *uap; + struct device *dev; }; static LIST_HEAD(pl011_dma_uarts); @@ -190,7 +374,7 @@ static int __init pl011_dma_initcall(void) list_for_each_safe(node, tmp, &pl011_dma_uarts) { struct dma_uap *dmau = list_entry(node, struct dma_uap, node); - pl011_dma_probe_initcall(dmau->uap); + pl011_dma_probe_initcall(dmau->dev, dmau->uap); list_del(node); kfree(dmau); } @@ -199,18 +383,19 @@ static int __init pl011_dma_initcall(void) device_initcall(pl011_dma_initcall); -static void pl011_dma_probe(struct uart_amba_port *uap) +static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap) { struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL); if (dmau) { dmau->uap = uap; + dmau->dev = dev; list_add_tail(&dmau->node, &pl011_dma_uarts); } } #else -static void pl011_dma_probe(struct uart_amba_port *uap) +static void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap) { - pl011_dma_probe_initcall(uap); + pl011_dma_probe_initcall(dev, uap); } #endif @@ -219,9 +404,10 @@ static void pl011_dma_remove(struct uart_amba_port *uap) /* TODO: remove the initcall if it has not yet executed */ if (uap->dmatx.chan) dma_release_channel(uap->dmatx.chan); + if (uap->dmarx.chan) + dma_release_channel(uap->dmarx.chan); } - /* Forward declare this for the refill routine */ static int pl011_dma_tx_refill(struct uart_amba_port *uap); @@ -330,7 +516,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap) return -EBUSY; } - desc = dma_dev->device_prep_slave_sg(chan, &dmatx->sg, 1, DMA_TO_DEVICE, + desc = dmaengine_prep_slave_sg(chan, &dmatx->sg, 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE); @@ -380,7 +566,7 @@ static int pl011_dma_tx_refill(struct uart_amba_port *uap) */ static bool pl011_dma_tx_irq(struct uart_amba_port *uap) { - if (!uap->using_dma) + if (!uap->using_tx_dma) return false; /* @@ -398,7 +584,7 @@ static bool pl011_dma_tx_irq(struct uart_amba_port *uap) /* * We don't have a TX buffer queued, so try to queue one. - * If we succesfully queued a buffer, mask the TX IRQ. + * If we successfully queued a buffer, mask the TX IRQ. */ if (pl011_dma_tx_refill(uap) > 0) { uap->im &= ~UART011_TXIM; @@ -432,7 +618,7 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) { u16 dmacr; - if (!uap->using_dma) + if (!uap->using_tx_dma) return false; if (!uap->port.x_char) { @@ -489,10 +675,12 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) * Locking: called with port lock held and IRQs disabled. */ static void pl011_dma_flush_buffer(struct uart_port *port) +__releases(&uap->port.lock) +__acquires(&uap->port.lock) { struct uart_amba_port *uap = (struct uart_amba_port *)port; - if (!uap->using_dma) + if (!uap->using_tx_dma) return; /* Avoid deadlock with the DMA engine callback */ @@ -508,9 +696,294 @@ static void pl011_dma_flush_buffer(struct uart_port *port) } } +static void pl011_dma_rx_callback(void *data); + +static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) +{ + struct dma_chan *rxchan = uap->dmarx.chan; + struct pl011_dmarx_data *dmarx = &uap->dmarx; + struct dma_async_tx_descriptor *desc; + struct pl011_sgbuf *sgbuf; + + if (!rxchan) + return -EIO; + + /* Start the RX DMA job */ + sgbuf = uap->dmarx.use_buf_b ? + &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; + desc = dmaengine_prep_slave_sg(rxchan, &sgbuf->sg, 1, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + /* + * If the DMA engine is busy and cannot prepare a + * channel, no big deal, the driver will fall back + * to interrupt mode as a result of this error code. + */ + if (!desc) { + uap->dmarx.running = false; + dmaengine_terminate_all(rxchan); + return -EBUSY; + } + + /* Some data to go along to the callback */ + desc->callback = pl011_dma_rx_callback; + desc->callback_param = uap; + dmarx->cookie = dmaengine_submit(desc); + dma_async_issue_pending(rxchan); + + uap->dmacr |= UART011_RXDMAE; + writew(uap->dmacr, uap->port.membase + UART011_DMACR); + uap->dmarx.running = true; + + uap->im &= ~UART011_RXIM; + writew(uap->im, uap->port.membase + UART011_IMSC); + + return 0; +} + +/* + * This is called when either the DMA job is complete, or + * the FIFO timeout interrupt occurred. This must be called + * with the port spinlock uap->port.lock held. + */ +static void pl011_dma_rx_chars(struct uart_amba_port *uap, + u32 pending, bool use_buf_b, + bool readfifo) +{ + struct tty_port *port = &uap->port.state->port; + struct pl011_sgbuf *sgbuf = use_buf_b ? + &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; + int dma_count = 0; + u32 fifotaken = 0; /* only used for vdbg() */ + + struct pl011_dmarx_data *dmarx = &uap->dmarx; + int dmataken = 0; + + if (uap->dmarx.poll_rate) { + /* The data can be taken by polling */ + dmataken = sgbuf->sg.length - dmarx->last_residue; + /* Recalculate the pending size */ + if (pending >= dmataken) + pending -= dmataken; + } + + /* Pick the remain data from the DMA */ + if (pending) { + + /* + * First take all chars in the DMA pipe, then look in the FIFO. + * Note that tty_insert_flip_buf() tries to take as many chars + * as it can. + */ + dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, + pending); + + uap->port.icount.rx += dma_count; + if (dma_count < pending) + dev_warn(uap->port.dev, + "couldn't insert all characters (TTY is full?)\n"); + } + + /* Reset the last_residue for Rx DMA poll */ + if (uap->dmarx.poll_rate) + dmarx->last_residue = sgbuf->sg.length; + + /* + * Only continue with trying to read the FIFO if all DMA chars have + * been taken first. + */ + if (dma_count == pending && readfifo) { + /* Clear any error flags */ + writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS, + uap->port.membase + UART011_ICR); + + /* + * If we read all the DMA'd characters, and we had an + * incomplete buffer, that could be due to an rx error, or + * maybe we just timed out. Read any pending chars and check + * the error status. + * + * Error conditions will only occur in the FIFO, these will + * trigger an immediate interrupt and stop the DMA job, so we + * will always find the error in the FIFO, never in the DMA + * buffer. + */ + fifotaken = pl011_fifo_to_tty(uap); + } + + spin_unlock(&uap->port.lock); + dev_vdbg(uap->port.dev, + "Took %d chars from DMA buffer and %d chars from the FIFO\n", + dma_count, fifotaken); + tty_flip_buffer_push(port); + spin_lock(&uap->port.lock); +} + +static void pl011_dma_rx_irq(struct uart_amba_port *uap) +{ + struct pl011_dmarx_data *dmarx = &uap->dmarx; + struct dma_chan *rxchan = dmarx->chan; + struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? + &dmarx->sgbuf_b : &dmarx->sgbuf_a; + size_t pending; + struct dma_tx_state state; + enum dma_status dmastat; + + /* + * Pause the transfer so we can trust the current counter, + * do this before we pause the PL011 block, else we may + * overflow the FIFO. + */ + if (dmaengine_pause(rxchan)) + dev_err(uap->port.dev, "unable to pause DMA transfer\n"); + dmastat = rxchan->device->device_tx_status(rxchan, + dmarx->cookie, &state); + if (dmastat != DMA_PAUSED) + dev_err(uap->port.dev, "unable to pause DMA transfer\n"); + + /* Disable RX DMA - incoming data will wait in the FIFO */ + uap->dmacr &= ~UART011_RXDMAE; + writew(uap->dmacr, uap->port.membase + UART011_DMACR); + uap->dmarx.running = false; + + pending = sgbuf->sg.length - state.residue; + BUG_ON(pending > PL011_DMA_BUFFER_SIZE); + /* Then we terminate the transfer - we now know our residue */ + dmaengine_terminate_all(rxchan); + + /* + * This will take the chars we have so far and insert + * into the framework. + */ + pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true); + + /* Switch buffer & re-trigger DMA job */ + dmarx->use_buf_b = !dmarx->use_buf_b; + if (pl011_dma_rx_trigger_dma(uap)) { + dev_dbg(uap->port.dev, "could not retrigger RX DMA job " + "fall back to interrupt mode\n"); + uap->im |= UART011_RXIM; + writew(uap->im, uap->port.membase + UART011_IMSC); + } +} + +static void pl011_dma_rx_callback(void *data) +{ + struct uart_amba_port *uap = data; + struct pl011_dmarx_data *dmarx = &uap->dmarx; + struct dma_chan *rxchan = dmarx->chan; + bool lastbuf = dmarx->use_buf_b; + struct pl011_sgbuf *sgbuf = dmarx->use_buf_b ? + &dmarx->sgbuf_b : &dmarx->sgbuf_a; + size_t pending; + struct dma_tx_state state; + int ret; + + /* + * This completion interrupt occurs typically when the + * RX buffer is totally stuffed but no timeout has yet + * occurred. When that happens, we just want the RX + * routine to flush out the secondary DMA buffer while + * we immediately trigger the next DMA job. + */ + spin_lock_irq(&uap->port.lock); + /* + * Rx data can be taken by the UART interrupts during + * the DMA irq handler. So we check the residue here. + */ + rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); + pending = sgbuf->sg.length - state.residue; + BUG_ON(pending > PL011_DMA_BUFFER_SIZE); + /* Then we terminate the transfer - we now know our residue */ + dmaengine_terminate_all(rxchan); + + uap->dmarx.running = false; + dmarx->use_buf_b = !lastbuf; + ret = pl011_dma_rx_trigger_dma(uap); + + pl011_dma_rx_chars(uap, pending, lastbuf, false); + spin_unlock_irq(&uap->port.lock); + /* + * Do this check after we picked the DMA chars so we don't + * get some IRQ immediately from RX. + */ + if (ret) { + dev_dbg(uap->port.dev, "could not retrigger RX DMA job " + "fall back to interrupt mode\n"); + uap->im |= UART011_RXIM; + writew(uap->im, uap->port.membase + UART011_IMSC); + } +} + +/* + * Stop accepting received characters, when we're shutting down or + * suspending this port. + * Locking: called with port lock held and IRQs disabled. + */ +static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) +{ + /* FIXME. Just disable the DMA enable */ + uap->dmacr &= ~UART011_RXDMAE; + writew(uap->dmacr, uap->port.membase + UART011_DMACR); +} + +/* + * Timer handler for Rx DMA polling. + * Every polling, It checks the residue in the dma buffer and transfer + * data to the tty. Also, last_residue is updated for the next polling. + */ +static void pl011_dma_rx_poll(unsigned long args) +{ + struct uart_amba_port *uap = (struct uart_amba_port *)args; + struct tty_port *port = &uap->port.state->port; + struct pl011_dmarx_data *dmarx = &uap->dmarx; + struct dma_chan *rxchan = uap->dmarx.chan; + unsigned long flags = 0; + unsigned int dmataken = 0; + unsigned int size = 0; + struct pl011_sgbuf *sgbuf; + int dma_count; + struct dma_tx_state state; + + sgbuf = dmarx->use_buf_b ? &uap->dmarx.sgbuf_b : &uap->dmarx.sgbuf_a; + rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state); + if (likely(state.residue < dmarx->last_residue)) { + dmataken = sgbuf->sg.length - dmarx->last_residue; + size = dmarx->last_residue - state.residue; + dma_count = tty_insert_flip_string(port, sgbuf->buf + dmataken, + size); + if (dma_count == size) + dmarx->last_residue = state.residue; + dmarx->last_jiffies = jiffies; + } + tty_flip_buffer_push(port); + + /* + * If no data is received in poll_timeout, the driver will fall back + * to interrupt mode. We will retrigger DMA at the first interrupt. + */ + if (jiffies_to_msecs(jiffies - dmarx->last_jiffies) + > uap->dmarx.poll_timeout) { + + spin_lock_irqsave(&uap->port.lock, flags); + pl011_dma_rx_stop(uap); + uap->im |= UART011_RXIM; + writew(uap->im, uap->port.membase + UART011_IMSC); + spin_unlock_irqrestore(&uap->port.lock, flags); + + uap->dmarx.running = false; + dmaengine_terminate_all(rxchan); + del_timer(&uap->dmarx.timer); + } else { + mod_timer(&uap->dmarx.timer, + jiffies + msecs_to_jiffies(uap->dmarx.poll_rate)); + } +} static void pl011_dma_startup(struct uart_amba_port *uap) { + int ret; + if (!uap->dmatx.chan) return; @@ -525,8 +998,33 @@ static void pl011_dma_startup(struct uart_amba_port *uap) /* The DMA buffer is now the FIFO the TTY subsystem can use */ uap->port.fifosize = PL011_DMA_BUFFER_SIZE; - uap->using_dma = true; + uap->using_tx_dma = true; + + if (!uap->dmarx.chan) + goto skip_rx; + /* Allocate and map DMA RX buffers */ + ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_a, + DMA_FROM_DEVICE); + if (ret) { + dev_err(uap->port.dev, "failed to init DMA %s: %d\n", + "RX buffer A", ret); + goto skip_rx; + } + + ret = pl011_sgbuf_init(uap->dmarx.chan, &uap->dmarx.sgbuf_b, + DMA_FROM_DEVICE); + if (ret) { + dev_err(uap->port.dev, "failed to init DMA %s: %d\n", + "RX buffer B", ret); + pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, + DMA_FROM_DEVICE); + goto skip_rx; + } + + uap->using_rx_dma = true; + +skip_rx: /* Turn on DMA error (RX/TX will be enabled on demand) */ uap->dmacr |= UART011_DMAONERR; writew(uap->dmacr, uap->port.membase + UART011_DMACR); @@ -539,11 +1037,27 @@ static void pl011_dma_startup(struct uart_amba_port *uap) if (uap->vendor->dma_threshold) writew(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16, uap->port.membase + ST_UART011_DMAWM); + + if (uap->using_rx_dma) { + if (pl011_dma_rx_trigger_dma(uap)) + dev_dbg(uap->port.dev, "could not trigger initial " + "RX DMA job, fall back to interrupt mode\n"); + if (uap->dmarx.poll_rate) { + init_timer(&(uap->dmarx.timer)); + uap->dmarx.timer.function = pl011_dma_rx_poll; + uap->dmarx.timer.data = (unsigned long)uap; + mod_timer(&uap->dmarx.timer, + jiffies + + msecs_to_jiffies(uap->dmarx.poll_rate)); + uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; + uap->dmarx.last_jiffies = jiffies; + } + } } static void pl011_dma_shutdown(struct uart_amba_port *uap) { - if (!uap->using_dma) + if (!(uap->using_tx_dma || uap->using_rx_dma)) return; /* Disable RX and TX DMA */ @@ -555,22 +1069,43 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap) writew(uap->dmacr, uap->port.membase + UART011_DMACR); spin_unlock_irq(&uap->port.lock); - /* In theory, this should already be done by pl011_dma_flush_buffer */ - dmaengine_terminate_all(uap->dmatx.chan); - if (uap->dmatx.queued) { - dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, - DMA_TO_DEVICE); - uap->dmatx.queued = false; + if (uap->using_tx_dma) { + /* In theory, this should already be done by pl011_dma_flush_buffer */ + dmaengine_terminate_all(uap->dmatx.chan); + if (uap->dmatx.queued) { + dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1, + DMA_TO_DEVICE); + uap->dmatx.queued = false; + } + + kfree(uap->dmatx.buf); + uap->using_tx_dma = false; } - kfree(uap->dmatx.buf); + if (uap->using_rx_dma) { + dmaengine_terminate_all(uap->dmarx.chan); + /* Clean up the RX DMA */ + pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_a, DMA_FROM_DEVICE); + pl011_sgbuf_free(uap->dmarx.chan, &uap->dmarx.sgbuf_b, DMA_FROM_DEVICE); + if (uap->dmarx.poll_rate) + del_timer_sync(&uap->dmarx.timer); + uap->using_rx_dma = false; + } +} + +static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) +{ + return uap->using_rx_dma; +} - uap->using_dma = false; +static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) +{ + return uap->using_rx_dma && uap->dmarx.running; } #else /* Blank functions if the DMA engine is not available */ -static inline void pl011_dma_probe(struct uart_amba_port *uap) +static inline void pl011_dma_probe(struct device *dev, struct uart_amba_port *uap) { } @@ -600,10 +1135,32 @@ static inline bool pl011_dma_tx_start(struct uart_amba_port *uap) return false; } +static inline void pl011_dma_rx_irq(struct uart_amba_port *uap) +{ +} + +static inline void pl011_dma_rx_stop(struct uart_amba_port *uap) +{ +} + +static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap) +{ + return -EIO; +} + +static inline bool pl011_dma_rx_available(struct uart_amba_port *uap) +{ + return false; +} + +static inline bool pl011_dma_rx_running(struct uart_amba_port *uap) +{ + return false; +} + #define pl011_dma_flush_buffer NULL #endif - static void pl011_stop_tx(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; @@ -630,6 +1187,8 @@ static void pl011_stop_rx(struct uart_port *port) uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM| UART011_PEIM|UART011_BEIM|UART011_OEIM); writew(uap->im, uap->port.membase + UART011_IMSC); + + pl011_dma_rx_stop(uap); } static void pl011_enable_ms(struct uart_port *port) @@ -641,53 +1200,36 @@ static void pl011_enable_ms(struct uart_port *port) } static void pl011_rx_chars(struct uart_amba_port *uap) +__releases(&uap->port.lock) +__acquires(&uap->port.lock) { - struct tty_struct *tty = uap->port.state->port.tty; - unsigned int status, ch, flag, max_count = 256; + pl011_fifo_to_tty(uap); - status = readw(uap->port.membase + UART01x_FR); - while ((status & UART01x_FR_RXFE) == 0 && max_count--) { - ch = readw(uap->port.membase + UART01x_DR) | UART_DUMMY_DR_RX; - flag = TTY_NORMAL; - uap->port.icount.rx++; - - /* - * Note that the error handling code is - * out of the main execution path - */ - if (unlikely(ch & UART_DR_ERROR)) { - if (ch & UART011_DR_BE) { - ch &= ~(UART011_DR_FE | UART011_DR_PE); - uap->port.icount.brk++; - if (uart_handle_break(&uap->port)) - goto ignore_char; - } else if (ch & UART011_DR_PE) - uap->port.icount.parity++; - else if (ch & UART011_DR_FE) - uap->port.icount.frame++; - if (ch & UART011_DR_OE) - uap->port.icount.overrun++; - - ch &= uap->port.read_status_mask; - - if (ch & UART011_DR_BE) - flag = TTY_BREAK; - else if (ch & UART011_DR_PE) - flag = TTY_PARITY; - else if (ch & UART011_DR_FE) - flag = TTY_FRAME; + spin_unlock(&uap->port.lock); + tty_flip_buffer_push(&uap->port.state->port); + /* + * If we were temporarily out of DMA mode for a while, + * attempt to switch back to DMA mode again. + */ + if (pl011_dma_rx_available(uap)) { + if (pl011_dma_rx_trigger_dma(uap)) { + dev_dbg(uap->port.dev, "could not trigger RX DMA job " + "fall back to interrupt mode again\n"); + uap->im |= UART011_RXIM; + writew(uap->im, uap->port.membase + UART011_IMSC); + } else { +#ifdef CONFIG_DMA_ENGINE + /* Start Rx DMA poll */ + if (uap->dmarx.poll_rate) { + uap->dmarx.last_jiffies = jiffies; + uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE; + mod_timer(&uap->dmarx.timer, + jiffies + + msecs_to_jiffies(uap->dmarx.poll_rate)); + } +#endif } - - if (uart_handle_sysrq_char(&uap->port, ch & 255)) - goto ignore_char; - - uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); - - ignore_char: - status = readw(uap->port.membase + UART01x_FR); } - spin_unlock(&uap->port.lock); - tty_flip_buffer_push(tty); spin_lock(&uap->port.lock); } @@ -757,18 +1299,35 @@ static irqreturn_t pl011_int(int irq, void *dev_id) unsigned long flags; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; int handled = 0; + unsigned int dummy_read; spin_lock_irqsave(&uap->port.lock, flags); - status = readw(uap->port.membase + UART011_MIS); if (status) { do { + if (uap->vendor->cts_event_workaround) { + /* workaround to make sure that all bits are unlocked.. */ + writew(0x00, uap->port.membase + UART011_ICR); + + /* + * WA: introduce 26ns(1 uart clk) delay before W1C; + * single apb access will incur 2 pclk(133.12Mhz) delay, + * so add 2 dummy reads + */ + dummy_read = readw(uap->port.membase + UART011_ICR); + dummy_read = readw(uap->port.membase + UART011_ICR); + } + writew(status & ~(UART011_TXIS|UART011_RTIS| UART011_RXIS), uap->port.membase + UART011_ICR); - if (status & (UART011_RTIS|UART011_RXIS)) - pl011_rx_chars(uap); + if (status & (UART011_RTIS|UART011_RXIS)) { + if (pl011_dma_rx_running(uap)) + pl011_dma_rx_irq(uap); + else + pl011_rx_chars(uap); + } if (status & (UART011_DSRMIS|UART011_DCDMIS| UART011_CTSMIS|UART011_RIMIS)) pl011_modem_status(uap); @@ -788,14 +1347,14 @@ static irqreturn_t pl011_int(int irq, void *dev_id) return IRQ_RETVAL(handled); } -static unsigned int pl01x_tx_empty(struct uart_port *port) +static unsigned int pl011_tx_empty(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; unsigned int status = readw(uap->port.membase + UART01x_FR); return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT; } -static unsigned int pl01x_get_mctrl(struct uart_port *port) +static unsigned int pl011_get_mctrl(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; unsigned int result = 0; @@ -858,11 +1417,40 @@ static void pl011_break_ctl(struct uart_port *port, int break_state) } #ifdef CONFIG_CONSOLE_POLL -static int pl010_get_poll_char(struct uart_port *port) + +static void pl011_quiesce_irqs(struct uart_port *port) +{ + struct uart_amba_port *uap = (struct uart_amba_port *)port; + unsigned char __iomem *regs = uap->port.membase; + + writew(readw(regs + UART011_MIS), regs + UART011_ICR); + /* + * There is no way to clear TXIM as this is "ready to transmit IRQ", so + * we simply mask it. start_tx() will unmask it. + * + * Note we can race with start_tx(), and if the race happens, the + * polling user might get another interrupt just after we clear it. + * But it should be OK and can happen even w/o the race, e.g. + * controller immediately got some new data and raised the IRQ. + * + * And whoever uses polling routines assumes that it manages the device + * (including tx queue), so we're also fine with start_tx()'s caller + * side. + */ + writew(readw(regs + UART011_IMSC) & ~UART011_TXIM, regs + UART011_IMSC); +} + +static int pl011_get_poll_char(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; unsigned int status; + /* + * The caller might need IRQs lowered, e.g. if used with KDB NMI + * debugger. + */ + pl011_quiesce_irqs(port); + status = readw(uap->port.membase + UART01x_FR); if (status & UART01x_FR_RXFE) return NO_POLL_CHAR; @@ -870,7 +1458,7 @@ static int pl010_get_poll_char(struct uart_port *port) return readw(uap->port.membase + UART01x_DR); } -static void pl010_put_poll_char(struct uart_port *port, +static void pl011_put_poll_char(struct uart_port *port, unsigned char ch) { struct uart_amba_port *uap = (struct uart_amba_port *)port; @@ -883,21 +1471,73 @@ static void pl010_put_poll_char(struct uart_port *port, #endif /* CONFIG_CONSOLE_POLL */ -static int pl011_startup(struct uart_port *port) +static int pl011_hwinit(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; - unsigned int cr; int retval; + /* Optionaly enable pins to be muxed in and configured */ + pinctrl_pm_select_default_state(port->dev); + /* * Try to enable the clock producer. */ - retval = clk_enable(uap->clk); + retval = clk_prepare_enable(uap->clk); if (retval) goto out; uap->port.uartclk = clk_get_rate(uap->clk); + /* Clear pending error and receive interrupts */ + writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS | + UART011_RTIS | UART011_RXIS, uap->port.membase + UART011_ICR); + + /* + * Save interrupts enable mask, and enable RX interrupts in case if + * the interrupt is used for NMI entry. + */ + uap->im = readw(uap->port.membase + UART011_IMSC); + writew(UART011_RTIM | UART011_RXIM, uap->port.membase + UART011_IMSC); + + if (dev_get_platdata(uap->port.dev)) { + struct amba_pl011_data *plat; + + plat = dev_get_platdata(uap->port.dev); + if (plat->init) + plat->init(); + } + return 0; + out: + return retval; +} + +static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h) +{ + writew(lcr_h, uap->port.membase + uap->lcrh_rx); + if (uap->lcrh_rx != uap->lcrh_tx) { + int i; + /* + * Wait 10 PCLKs before writing LCRH_TX register, + * to get this delay write read only register 10 times + */ + for (i = 0; i < 10; ++i) + writew(0xff, uap->port.membase + UART011_MIS); + writew(lcr_h, uap->port.membase + uap->lcrh_tx); + } +} + +static int pl011_startup(struct uart_port *port) +{ + struct uart_amba_port *uap = (struct uart_amba_port *)port; + unsigned int cr, lcr_h, fbrd, ibrd; + int retval; + + retval = pl011_hwinit(port); + if (retval) + goto clk_dis; + + writew(uap->im, uap->port.membase + UART011_IMSC); + /* * Allocate the IRQ */ @@ -908,33 +1548,35 @@ static int pl011_startup(struct uart_port *port) writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS); /* - * Provoke TX FIFO interrupt into asserting. + * Provoke TX FIFO interrupt into asserting. Taking care to preserve + * baud rate and data format specified by FBRD, IBRD and LCRH as the + * UART may already be in use as a console. */ + spin_lock_irq(&uap->port.lock); + + fbrd = readw(uap->port.membase + UART011_FBRD); + ibrd = readw(uap->port.membase + UART011_IBRD); + lcr_h = readw(uap->port.membase + uap->lcrh_rx); + cr = UART01x_CR_UARTEN | UART011_CR_TXE | UART011_CR_LBE; writew(cr, uap->port.membase + UART011_CR); writew(0, uap->port.membase + UART011_FBRD); writew(1, uap->port.membase + UART011_IBRD); - writew(0, uap->port.membase + uap->lcrh_rx); - if (uap->lcrh_tx != uap->lcrh_rx) { - int i; - /* - * Wait 10 PCLKs before writing LCRH_TX register, - * to get this delay write read only register 10 times - */ - for (i = 0; i < 10; ++i) - writew(0xff, uap->port.membase + UART011_MIS); - writew(0, uap->port.membase + uap->lcrh_tx); - } + pl011_write_lcr_h(uap, 0); writew(0, uap->port.membase + UART01x_DR); while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY) barrier(); - cr = UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; + writew(fbrd, uap->port.membase + UART011_FBRD); + writew(ibrd, uap->port.membase + UART011_IBRD); + pl011_write_lcr_h(uap, lcr_h); + + /* restore RTS and DTR */ + cr = uap->old_cr & (UART011_CR_RTS | UART011_CR_DTR); + cr |= UART01x_CR_UARTEN | UART011_CR_RXE | UART011_CR_TXE; writew(cr, uap->port.membase + UART011_CR); - /* Clear pending error interrupts */ - writew(UART011_OEIS | UART011_BEIS | UART011_PEIS | UART011_FEIS, - uap->port.membase + UART011_ICR); + spin_unlock_irq(&uap->port.lock); /* * initialise the old status of the modem signals @@ -945,18 +1587,24 @@ static int pl011_startup(struct uart_port *port) pl011_dma_startup(uap); /* - * Finally, enable interrupts + * Finally, enable interrupts, only timeouts when using DMA + * if initial RX DMA job failed, start in interrupt mode + * as well. */ spin_lock_irq(&uap->port.lock); - uap->im = UART011_RXIM | UART011_RTIM; + /* Clear out any spuriously appearing RX interrupts */ + writew(UART011_RTIS | UART011_RXIS, + uap->port.membase + UART011_ICR); + uap->im = UART011_RTIM; + if (!pl011_dma_rx_running(uap)) + uap->im |= UART011_RXIM; writew(uap->im, uap->port.membase + UART011_IMSC); spin_unlock_irq(&uap->port.lock); return 0; clk_dis: - clk_disable(uap->clk); - out: + clk_disable_unprepare(uap->clk); return retval; } @@ -973,6 +1621,7 @@ static void pl011_shutdown_channel(struct uart_amba_port *uap, static void pl011_shutdown(struct uart_port *port) { struct uart_amba_port *uap = (struct uart_amba_port *)port; + unsigned int cr; /* * disable all interrupts @@ -992,9 +1641,18 @@ static void pl011_shutdown(struct uart_port *port) /* * disable the port + * disable the port. It should not disable RTS and DTR. + * Also RTS and DTR state should be preserved to restore + * it during startup(). */ uap->autorts = false; - writew(UART01x_CR_UARTEN | UART011_CR_TXE, uap->port.membase + UART011_CR); + spin_lock_irq(&uap->port.lock); + cr = readw(uap->port.membase + UART011_CR); + uap->old_cr = cr; + cr &= UART011_CR_RTS | UART011_CR_DTR; + cr |= UART01x_CR_UARTEN | UART011_CR_TXE; + writew(cr, uap->port.membase + UART011_CR); + spin_unlock_irq(&uap->port.lock); /* * disable break condition and fifos @@ -1006,7 +1664,18 @@ static void pl011_shutdown(struct uart_port *port) /* * Shut down the clock producer */ - clk_disable(uap->clk); + clk_disable_unprepare(uap->clk); + /* Optionally let pins go into sleep states */ + pinctrl_pm_select_sleep_state(port->dev); + + if (dev_get_platdata(uap->port.dev)) { + struct amba_pl011_data *plat; + + plat = dev_get_platdata(uap->port.dev); + if (plat->exit) + plat->exit(); + } + } static void @@ -1028,6 +1697,13 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, */ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / clkdiv); +#ifdef CONFIG_DMA_ENGINE + /* + * Adjust RX DMA polling rate with baud rate if not specified. + */ + if (uap->dmarx.auto_poll_rate) + uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud); +#endif if (baud > port->uartclk/16) quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud); @@ -1068,7 +1744,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, port->read_status_mask = UART011_DR_OE | 255; if (termios->c_iflag & INPCK) port->read_status_mask |= UART011_DR_FE | UART011_DR_PE; - if (termios->c_iflag & (BRKINT | PARMRK)) + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= UART011_DR_BE; /* @@ -1118,26 +1794,29 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios, old_cr &= ~ST_UART011_CR_OVSFACT; } + /* + * Workaround for the ST Micro oversampling variants to + * increase the bitrate slightly, by lowering the divisor, + * to avoid delayed sampling of start bit at high speeds, + * else we see data corruption. + */ + if (uap->vendor->oversampling) { + if ((baud >= 3000000) && (baud < 3250000) && (quot > 1)) + quot -= 1; + else if ((baud > 3250000) && (quot > 2)) + quot -= 2; + } /* Set baud rate */ writew(quot & 0x3f, port->membase + UART011_FBRD); writew(quot >> 6, port->membase + UART011_IBRD); /* * ----------v----------v----------v----------v----- - * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L + * NOTE: lcrh_tx and lcrh_rx MUST BE WRITTEN AFTER + * UART011_FBRD & UART011_IBRD. * ----------^----------^----------^----------^----- */ - writew(lcr_h, port->membase + uap->lcrh_rx); - if (uap->lcrh_rx != uap->lcrh_tx) { - int i; - /* - * Wait 10 PCLKs before writing LCRH_TX register, - * to get this delay write read only register 10 times - */ - for (i = 0; i < 10; ++i) - writew(0xff, uap->port.membase + UART011_MIS); - writew(lcr_h, port->membase + uap->lcrh_tx); - } + pl011_write_lcr_h(uap, lcr_h); writew(old_cr, port->membase + UART011_CR); spin_unlock_irqrestore(&port->lock, flags); @@ -1152,7 +1831,7 @@ static const char *pl011_type(struct uart_port *port) /* * Release the memory region(s) being used by 'port' */ -static void pl010_release_port(struct uart_port *port) +static void pl011_release_port(struct uart_port *port) { release_mem_region(port->mapbase, SZ_4K); } @@ -1160,7 +1839,7 @@ static void pl010_release_port(struct uart_port *port) /* * Request the memory region(s) being used by 'port' */ -static int pl010_request_port(struct uart_port *port) +static int pl011_request_port(struct uart_port *port) { return request_mem_region(port->mapbase, SZ_4K, "uart-pl011") != NULL ? 0 : -EBUSY; @@ -1169,18 +1848,18 @@ static int pl010_request_port(struct uart_port *port) /* * Configure/autoconfigure the port. */ -static void pl010_config_port(struct uart_port *port, int flags) +static void pl011_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_AMBA; - pl010_request_port(port); + pl011_request_port(port); } } /* * verify the new serial_struct (for TIOCSSERIAL). */ -static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser) +static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA) @@ -1193,9 +1872,9 @@ static int pl010_verify_port(struct uart_port *port, struct serial_struct *ser) } static struct uart_ops amba_pl011_pops = { - .tx_empty = pl01x_tx_empty, + .tx_empty = pl011_tx_empty, .set_mctrl = pl011_set_mctrl, - .get_mctrl = pl01x_get_mctrl, + .get_mctrl = pl011_get_mctrl, .stop_tx = pl011_stop_tx, .start_tx = pl011_start_tx, .stop_rx = pl011_stop_rx, @@ -1206,13 +1885,14 @@ static struct uart_ops amba_pl011_pops = { .flush_buffer = pl011_dma_flush_buffer, .set_termios = pl011_set_termios, .type = pl011_type, - .release_port = pl010_release_port, - .request_port = pl010_request_port, - .config_port = pl010_config_port, - .verify_port = pl010_verify_port, + .release_port = pl011_release_port, + .request_port = pl011_request_port, + .config_port = pl011_config_port, + .verify_port = pl011_verify_port, #ifdef CONFIG_CONSOLE_POLL - .poll_get_char = pl010_get_poll_char, - .poll_put_char = pl010_put_poll_char, + .poll_init = pl011_hwinit, + .poll_get_char = pl011_get_poll_char, + .poll_put_char = pl011_put_poll_char, #endif }; @@ -1234,9 +1914,19 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) { struct uart_amba_port *uap = amba_ports[co->index]; unsigned int status, old_cr, new_cr; + unsigned long flags; + int locked = 1; clk_enable(uap->clk); + local_irq_save(flags); + if (uap->port.sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&uap->port.lock); + else + spin_lock(&uap->port.lock); + /* * First save the CR then disable the interrupts */ @@ -1256,6 +1946,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) } while (status & UART01x_FR_BUSY); writew(old_cr, uap->port.membase + UART011_CR); + if (locked) + spin_unlock(&uap->port.lock); + local_irq_restore(flags); + clk_disable(uap->clk); } @@ -1301,6 +1995,7 @@ static int __init pl011_console_setup(struct console *co, char *options) int bits = 8; int parity = 'n'; int flow = 'n'; + int ret; /* * Check whether an invalid uart number has been specified, and @@ -1313,6 +2008,21 @@ static int __init pl011_console_setup(struct console *co, char *options) if (!uap) return -ENODEV; + /* Allow pins to be muxed in and configured */ + pinctrl_pm_select_default_state(uap->port.dev); + + ret = clk_prepare(uap->clk); + if (ret) + return ret; + + if (dev_get_platdata(uap->port.dev)) { + struct amba_pl011_data *plat; + + plat = dev_get_platdata(uap->port.dev); + if (plat->init) + plat->init(); + } + uap->port.uartclk = clk_get_rate(uap->clk); if (options) @@ -1335,6 +2045,35 @@ static struct console amba_console = { }; #define AMBA_CONSOLE (&amba_console) + +static void pl011_putc(struct uart_port *port, int c) +{ + while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF) + ; + writeb(c, port->membase + UART01x_DR); + while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY) + ; +} + +static void pl011_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, pl011_putc); +} + +static int __init pl011_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = pl011_early_write; + return 0; +} +EARLYCON_DECLARE(pl011, pl011_early_console_setup); +OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup); + #else #define AMBA_CONSOLE NULL #endif @@ -1349,7 +2088,39 @@ static struct uart_driver amba_reg = { .cons = AMBA_CONSOLE, }; -static int pl011_probe(struct amba_device *dev, struct amba_id *id) +static int pl011_probe_dt_alias(int index, struct device *dev) +{ + struct device_node *np; + static bool seen_dev_with_alias = false; + static bool seen_dev_without_alias = false; + int ret = index; + + if (!IS_ENABLED(CONFIG_OF)) + return ret; + + np = dev->of_node; + if (!np) + return ret; + + ret = of_alias_get_id(np, "serial"); + if (IS_ERR_VALUE(ret)) { + seen_dev_without_alias = true; + ret = index; + } else { + seen_dev_with_alias = true; + if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) { + dev_warn(dev, "requested serial port %d not available.\n", ret); + ret = index; + } + } + + if (seen_dev_with_alias && seen_dev_without_alias) + dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n"); + + return ret; +} + +static int pl011_probe(struct amba_device *dev, const struct amba_id *id) { struct uart_amba_port *uap; struct vendor_data *vendor = id->data; @@ -1365,28 +2136,33 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id) goto out; } - uap = kzalloc(sizeof(struct uart_amba_port), GFP_KERNEL); + uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port), + GFP_KERNEL); if (uap == NULL) { ret = -ENOMEM; goto out; } - base = ioremap(dev->res.start, resource_size(&dev->res)); + i = pl011_probe_dt_alias(i, &dev->dev); + + base = devm_ioremap(&dev->dev, dev->res.start, + resource_size(&dev->res)); if (!base) { ret = -ENOMEM; - goto free; + goto out; } - uap->clk = clk_get(&dev->dev, NULL); + uap->clk = devm_clk_get(&dev->dev, NULL); if (IS_ERR(uap->clk)) { ret = PTR_ERR(uap->clk); - goto unmap; + goto out; } uap->vendor = vendor; uap->lcrh_rx = vendor->lcrh_rx; uap->lcrh_tx = vendor->lcrh_tx; - uap->fifosize = vendor->fifosize; + uap->old_cr = 0; + uap->fifosize = vendor->get_fifosize(dev); uap->port.dev = &dev->dev; uap->port.mapbase = dev->res.start; uap->port.membase = base; @@ -1396,23 +2172,31 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id) uap->port.ops = &amba_pl011_pops; uap->port.flags = UPF_BOOT_AUTOCONF; uap->port.line = i; - pl011_dma_probe(uap); + pl011_dma_probe(&dev->dev, uap); + + /* Ensure interrupts from this UART are masked and cleared */ + writew(0, uap->port.membase + UART011_IMSC); + writew(0xffff, uap->port.membase + UART011_ICR); snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev)); amba_ports[i] = uap; amba_set_drvdata(dev, uap); + + if (!amba_reg.state) { + ret = uart_register_driver(&amba_reg); + if (ret < 0) { + pr_err("Failed to register AMBA-PL011 driver\n"); + return ret; + } + } + ret = uart_add_one_port(&amba_reg, &uap->port); if (ret) { - amba_set_drvdata(dev, NULL); amba_ports[i] = NULL; + uart_unregister_driver(&amba_reg); pl011_dma_remove(uap); - clk_put(uap->clk); - unmap: - iounmap(base); - free: - kfree(uap); } out: return ret; @@ -1421,27 +2205,27 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id) static int pl011_remove(struct amba_device *dev) { struct uart_amba_port *uap = amba_get_drvdata(dev); + bool busy = false; int i; - amba_set_drvdata(dev, NULL); - uart_remove_one_port(&amba_reg, &uap->port); for (i = 0; i < ARRAY_SIZE(amba_ports); i++) if (amba_ports[i] == uap) amba_ports[i] = NULL; + else if (amba_ports[i]) + busy = true; pl011_dma_remove(uap); - iounmap(uap->port.membase); - clk_put(uap->clk); - kfree(uap); + if (!busy) + uart_unregister_driver(&amba_reg); return 0; } -#ifdef CONFIG_PM -static int pl011_suspend(struct amba_device *dev, pm_message_t state) +#ifdef CONFIG_PM_SLEEP +static int pl011_suspend(struct device *dev) { - struct uart_amba_port *uap = amba_get_drvdata(dev); + struct uart_amba_port *uap = dev_get_drvdata(dev); if (!uap) return -EINVAL; @@ -1449,9 +2233,9 @@ static int pl011_suspend(struct amba_device *dev, pm_message_t state) return uart_suspend_port(&amba_reg, &uap->port); } -static int pl011_resume(struct amba_device *dev) +static int pl011_resume(struct device *dev) { - struct uart_amba_port *uap = amba_get_drvdata(dev); + struct uart_amba_port *uap = dev_get_drvdata(dev); if (!uap) return -EINVAL; @@ -1460,6 +2244,8 @@ static int pl011_resume(struct amba_device *dev) } #endif +static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume); + static struct amba_id pl011_ids[] = { { .id = 0x00041011, @@ -1474,37 +2260,28 @@ static struct amba_id pl011_ids[] = { { 0, 0 }, }; +MODULE_DEVICE_TABLE(amba, pl011_ids); + static struct amba_driver pl011_driver = { .drv = { .name = "uart-pl011", + .pm = &pl011_dev_pm_ops, }, .id_table = pl011_ids, .probe = pl011_probe, .remove = pl011_remove, -#ifdef CONFIG_PM - .suspend = pl011_suspend, - .resume = pl011_resume, -#endif }; static int __init pl011_init(void) { - int ret; printk(KERN_INFO "Serial: AMBA PL011 UART driver\n"); - ret = uart_register_driver(&amba_reg); - if (ret == 0) { - ret = amba_driver_register(&pl011_driver); - if (ret) - uart_unregister_driver(&amba_reg); - } - return ret; + return amba_driver_register(&pl011_driver); } static void __exit pl011_exit(void) { amba_driver_unregister(&pl011_driver); - uart_unregister_driver(&amba_reg); } /* |