#include <linux/highmem.h>
#include <linux/log2.h>
#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
* is asserted (likewise for RX)
* @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
* is asserted (likewise for RX)
+ * @broken_blockend: the MCI_DATABLOCKEND is broken on the hardware
+ * and will not work at all.
+ * @broken_blockend_dma: the MCI_DATABLOCKEND is broken on the hardware when
+ * using DMA.
+ * @sdio: variant supports SDIO
+ * @st_clkdiv: true if using a ST-specific clock divider algorithm
*/
struct variant_data {
unsigned int clkreg;
unsigned int datalength_bits;
unsigned int fifosize;
unsigned int fifohalfsize;
+ bool broken_blockend;
+ bool broken_blockend_dma;
+ bool sdio;
+ bool st_clkdiv;
};
static struct variant_data variant_arm = {
.fifohalfsize = 8 * 4,
.clkreg_enable = 1 << 13, /* HWFCEN */
.datalength_bits = 16,
+ .broken_blockend_dma = true,
+ .sdio = true,
};
static struct variant_data variant_ux500 = {
.clkreg = MCI_CLK_ENABLE,
.clkreg_enable = 1 << 14, /* HWFCEN */
.datalength_bits = 24,
+ .broken_blockend = true,
+ .sdio = true,
+ .st_clkdiv = true,
};
+
/*
* This must be called with host->lock held
*/
if (desired >= host->mclk) {
clk = MCI_CLK_BYPASS;
host->cclk = host->mclk;
+ } else if (variant->st_clkdiv) {
+ /*
+ * DB8500 TRM says f = mclk / (clkdiv + 2)
+ * => clkdiv = (mclk / f) - 2
+ * Round the divider up so we don't exceed the max
+ * frequency
+ */
+ clk = DIV_ROUND_UP(host->mclk, desired) - 2;
+ if (clk >= 256)
+ clk = 255;
+ host->cclk = host->mclk / (clk + 2);
} else {
+ /*
+ * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
+ * => clkdiv = mclk / (2 * f) - 1
+ */
clk = host->mclk / (2 * desired) - 1;
if (clk >= 256)
clk = 255;
spin_lock(&host->lock);
}
+static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
+{
+ void __iomem *base = host->base;
+
+ if (host->singleirq) {
+ unsigned int mask0 = readl(base + MMCIMASK0);
+
+ mask0 &= ~MCI_IRQ1MASK;
+ mask0 |= mask;
+
+ writel(mask0, base + MMCIMASK0);
+ }
+
+ writel(mask, base + MMCIMASK1);
+}
+
static void mmci_stop_data(struct mmci_host *host)
{
writel(0, host->base + MMCIDATACTRL);
- writel(0, host->base + MMCIMASK1);
+ mmci_set_mask1(host, 0);
host->data = NULL;
}
host->data = data;
host->size = data->blksz * data->blocks;
host->data_xfered = 0;
+ host->blockend = false;
+ host->dataend = false;
mmci_init_sg(host, data);
irqmask = MCI_TXFIFOHALFEMPTYMASK;
}
+ /* The ST Micro variants has a special bit to enable SDIO */
+ if (variant->sdio && host->mmc->card)
+ if (mmc_card_sdio(host->mmc->card))
+ datactrl |= MCI_ST_DPSM_SDIOEN;
+
writel(datactrl, base + MMCIDATACTRL);
writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
- writel(irqmask, base + MMCIMASK1);
+ mmci_set_mask1(host, irqmask);
}
static void
mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
unsigned int status)
{
- if (status & MCI_DATABLOCKEND) {
- host->data_xfered += data->blksz;
-#ifdef CONFIG_ARCH_U300
- /*
- * On the U300 some signal or other is
- * badly routed so that a data write does
- * not properly terminate with a MCI_DATAEND
- * status flag. This quirk will make writes
- * work again.
- */
- if (data->flags & MMC_DATA_WRITE)
- status |= MCI_DATAEND;
-#endif
- }
+ struct variant_data *variant = host->variant;
+
+ /* First check for errors */
if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ (status %08x)\n", status);
if (status & MCI_DATACRCFAIL)
data->error = -ETIMEDOUT;
else if (status & (MCI_TXUNDERRUN|MCI_RXOVERRUN))
data->error = -EIO;
- status |= MCI_DATAEND;
+
+ /* Force-complete the transaction */
+ host->blockend = true;
+ host->dataend = true;
/*
* We hit an error condition. Ensure that any data
local_irq_restore(flags);
}
}
- if (status & MCI_DATAEND) {
+
+ /*
+ * On ARM variants in PIO mode, MCI_DATABLOCKEND
+ * is always sent first, and we increase the
+ * transfered number of bytes for that IRQ. Then
+ * MCI_DATAEND follows and we conclude the transaction.
+ *
+ * On the Ux500 single-IRQ variant MCI_DATABLOCKEND
+ * doesn't seem to immediately clear from the status,
+ * so we can't use it keep count when only one irq is
+ * used because the irq will hit for other reasons, and
+ * then the flag is still up. So we use the MCI_DATAEND
+ * IRQ at the end of the entire transfer because
+ * MCI_DATABLOCKEND is broken.
+ *
+ * In the U300, the IRQs can arrive out-of-order,
+ * e.g. MCI_DATABLOCKEND sometimes arrives after MCI_DATAEND,
+ * so for this case we use the flags "blockend" and
+ * "dataend" to make sure both IRQs have arrived before
+ * concluding the transaction. (This does not apply
+ * to the Ux500 which doesn't fire MCI_DATABLOCKEND
+ * at all.) In DMA mode it suffers from the same problem
+ * as the Ux500.
+ */
+ if (status & MCI_DATABLOCKEND) {
+ /*
+ * Just being a little over-cautious, we do not
+ * use this progressive update if the hardware blockend
+ * flag is unreliable: since it can stay high between
+ * IRQs it will corrupt the transfer counter.
+ */
+ if (!variant->broken_blockend)
+ host->data_xfered += data->blksz;
+ host->blockend = true;
+ }
+
+ if (status & MCI_DATAEND)
+ host->dataend = true;
+
+ /*
+ * On variants with broken blockend we shall only wait for dataend,
+ * on others we must sync with the blockend signal since they can
+ * appear out-of-order.
+ */
+ if (host->dataend && (host->blockend || variant->broken_blockend)) {
mmci_stop_data(host);
+ /* Reset these flags */
+ host->blockend = false;
+ host->dataend = false;
+
+ /*
+ * Variants with broken blockend flags need to handle the
+ * end of the entire transfer here.
+ */
+ if (variant->broken_blockend && !data->error)
+ host->data_xfered += data->blksz * data->blocks;
+
if (!data->stop) {
mmci_request_end(host, data->mrq);
} else {
variant->fifosize : variant->fifohalfsize;
count = min(remain, maxcnt);
- writesl(base + MMCIFIFO, ptr, count >> 2);
+ /*
+ * The ST Micro variant for SDIO transfer sizes
+ * less then 8 bytes should have clock H/W flow
+ * control disabled.
+ */
+ if (variant->sdio &&
+ mmc_card_sdio(host->mmc->card)) {
+ if (count < 8)
+ writel(readl(host->base + MMCICLOCK) &
+ ~variant->clkreg_enable,
+ host->base + MMCICLOCK);
+ else
+ writel(readl(host->base + MMCICLOCK) |
+ variant->clkreg_enable,
+ host->base + MMCICLOCK);
+ }
+
+ /*
+ * SDIO especially may want to send something that is
+ * not divisible by 4 (as opposed to card sectors
+ * etc), and the FIFO only accept full 32-bit writes.
+ * So compensate by adding +3 on the count, a single
+ * byte become a 32bit write, 7 bytes will be two
+ * 32bit writes etc.
+ */
+ writesl(base + MMCIFIFO, ptr, (count + 3) >> 2);
ptr += count;
remain -= count;
* "any data available" mode.
*/
if (status & MCI_RXACTIVE && host->size < variant->fifosize)
- writel(MCI_RXDATAAVLBLMASK, base + MMCIMASK1);
+ mmci_set_mask1(host, MCI_RXDATAAVLBLMASK);
/*
* If we run out of data, disable the data IRQs; this
* stops us racing with our data end IRQ.
*/
if (host->size == 0) {
- writel(0, base + MMCIMASK1);
+ mmci_set_mask1(host, 0);
writel(readl(base + MMCIMASK0) | MCI_DATAENDMASK, base + MMCIMASK0);
}
struct mmc_data *data;
status = readl(host->base + MMCISTATUS);
+
+ if (host->singleirq) {
+ if (status & readl(host->base + MMCIMASK1))
+ mmci_pio_irq(irq, dev_id);
+
+ status &= ~MCI_IRQ1MASK;
+ }
+
status &= readl(host->base + MMCIMASK0);
writel(status, host->base + MMCICLEAR);
struct variant_data *variant = id->data;
struct mmci_host *host;
struct mmc_host *mmc;
+ unsigned int mask;
int ret;
/* must have platform data */
if (ret)
goto unmap;
- ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED, DRIVER_NAME " (pio)", host);
- if (ret)
- goto irq0_free;
+ if (dev->irq[1] == NO_IRQ)
+ host->singleirq = true;
+ else {
+ ret = request_irq(dev->irq[1], mmci_pio_irq, IRQF_SHARED,
+ DRIVER_NAME " (pio)", host);
+ if (ret)
+ goto irq0_free;
+ }
- writel(MCI_IRQENABLE, host->base + MMCIMASK0);
+ mask = MCI_IRQENABLE;
+ /* Don't use the datablockend flag if it's broken */
+ if (variant->broken_blockend)
+ mask &= ~MCI_DATABLOCKEND;
- amba_set_drvdata(dev, mmc);
+ writel(mask, host->base + MMCIMASK0);
- mmc_add_host(mmc);
+ amba_set_drvdata(dev, mmc);
- dev_info(&dev->dev, "%s: MMCI rev %x cfg %02x at 0x%016llx irq %d,%d\n",
- mmc_hostname(mmc), amba_rev(dev), amba_config(dev),
+ dev_info(&dev->dev, "%s: PL%03x rev%u at 0x%08llx irq %d,%d\n",
+ mmc_hostname(mmc), amba_part(dev), amba_rev(dev),
(unsigned long long)dev->res.start, dev->irq[0], dev->irq[1]);
+ mmc_add_host(mmc);
+
return 0;
irq0_free:
writel(0, host->base + MMCIDATACTRL);
free_irq(dev->irq[0], host);
- free_irq(dev->irq[1], host);
+ if (!host->singleirq)
+ free_irq(dev->irq[1], host);
if (host->gpio_wp != -ENOSYS)
gpio_free(host->gpio_wp);
*
* Copyright 1999 ARM Limited
* Copyright (C) 2000 Deep Blue Solutions Ltd.
+ * Copyright (C) 2010 ST-Ericsson SA
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include <linux/amba/serial.h>
#include <linux/clk.h>
#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
#include <asm/io.h>
#include <asm/sizes.h>
#define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
#define UART_DUMMY_DR_RX (1 << 16)
-/*
- * We wrap our port structure around the generic uart_port.
- */
-struct uart_amba_port {
- struct uart_port port;
- struct clk *clk;
- unsigned int im; /* interrupt mask */
- unsigned int old_status;
- unsigned int ifls; /* vendor-specific */
- unsigned int lcrh_tx; /* vendor-specific */
- unsigned int lcrh_rx; /* vendor-specific */
- bool oversampling; /* vendor-specific */
- bool autorts;
-};
-
/* There is by now at least one vendor with differing details, so handle it */
struct vendor_data {
unsigned int ifls;
unsigned int lcrh_tx;
unsigned int lcrh_rx;
bool oversampling;
+ bool dma_threshold;
};
static struct vendor_data vendor_arm = {
.lcrh_tx = UART011_LCRH,
.lcrh_rx = UART011_LCRH,
.oversampling = false,
+ .dma_threshold = false,
};
static struct vendor_data vendor_st = {
.lcrh_tx = ST_UART011_LCRH_TX,
.lcrh_rx = ST_UART011_LCRH_RX,
.oversampling = true,
+ .dma_threshold = true,
+};
+
+/* Deals with DMA transactions */
+struct pl011_dmatx_data {
+ struct dma_chan *chan;
+ struct scatterlist sg;
+ char *buf;
+ bool queued;
};
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_amba_port {
+ struct uart_port port;
+ struct clk *clk;
+ const struct vendor_data *vendor;
+ unsigned int dmacr; /* dma control reg */
+ unsigned int im; /* interrupt mask */
+ unsigned int old_status;
+ unsigned int fifosize; /* vendor-specific */
+ unsigned int lcrh_tx; /* vendor-specific */
+ unsigned int lcrh_rx; /* vendor-specific */
+ bool autorts;
+ char type[12];
+#ifdef CONFIG_DMA_ENGINE
+ /* DMA stuff */
+ bool using_dma;
+ struct pl011_dmatx_data dmatx;
+#endif
+};
+
+/*
+ * 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.
+ */
+#ifdef CONFIG_DMA_ENGINE
+
+#define PL011_DMA_BUFFER_SIZE PAGE_SIZE
+
+static void pl011_dma_probe_initcall(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 dma_slave_config tx_conf = {
+ .dst_addr = uap->port.mapbase + UART01x_DR,
+ .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+ .direction = DMA_TO_DEVICE,
+ .dst_maxburst = uap->fifosize >> 1,
+ };
+ 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;
+ }
+
+ /* 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;
+ }
+
+ dmaengine_slave_config(chan, &tx_conf);
+ uap->dmatx.chan = chan;
+
+ dev_info(uap->port.dev, "DMA channel TX %s\n",
+ dma_chan_name(uap->dmatx.chan));
+}
+
+#ifndef MODULE
+/*
+ * Stack up the UARTs and let the above initcall be done at device
+ * initcall time, because the serial driver is called as an arch
+ * initcall, and at this time the DMA subsystem is not yet registered.
+ * At this point the driver will switch over to using DMA where desired.
+ */
+struct dma_uap {
+ struct list_head node;
+ struct uart_amba_port *uap;
+};
+
+static LIST_HEAD(pl011_dma_uarts);
+
+static int __init pl011_dma_initcall(void)
+{
+ struct list_head *node, *tmp;
+
+ 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);
+ list_del(node);
+ kfree(dmau);
+ }
+ return 0;
+}
+
+device_initcall(pl011_dma_initcall);
+
+static void pl011_dma_probe(struct uart_amba_port *uap)
+{
+ struct dma_uap *dmau = kzalloc(sizeof(struct dma_uap), GFP_KERNEL);
+ if (dmau) {
+ dmau->uap = uap;
+ list_add_tail(&dmau->node, &pl011_dma_uarts);
+ }
+}
+#else
+static void pl011_dma_probe(struct uart_amba_port *uap)
+{
+ pl011_dma_probe_initcall(uap);
+}
+#endif
+
+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);
+}
+
+
+/* Forward declare this for the refill routine */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap);
+
+/*
+ * The current DMA TX buffer has been sent.
+ * Try to queue up another DMA buffer.
+ */
+static void pl011_dma_tx_callback(void *data)
+{
+ struct uart_amba_port *uap = data;
+ struct pl011_dmatx_data *dmatx = &uap->dmatx;
+ unsigned long flags;
+ u16 dmacr;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+ if (uap->dmatx.queued)
+ dma_unmap_sg(dmatx->chan->device->dev, &dmatx->sg, 1,
+ DMA_TO_DEVICE);
+
+ dmacr = uap->dmacr;
+ uap->dmacr = dmacr & ~UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+
+ /*
+ * If TX DMA was disabled, it means that we've stopped the DMA for
+ * some reason (eg, XOFF received, or we want to send an X-char.)
+ *
+ * Note: we need to be careful here of a potential race between DMA
+ * and the rest of the driver - if the driver disables TX DMA while
+ * a TX buffer completing, we must update the tx queued status to
+ * get further refills (hence we check dmacr).
+ */
+ if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
+ uart_circ_empty(&uap->port.state->xmit)) {
+ uap->dmatx.queued = false;
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+ return;
+ }
+
+ if (pl011_dma_tx_refill(uap) <= 0) {
+ /*
+ * We didn't queue a DMA buffer for some reason, but we
+ * have data pending to be sent. Re-enable the TX IRQ.
+ */
+ uap->im |= UART011_TXIM;
+ writew(uap->im, uap->port.membase + UART011_IMSC);
+ }
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+/*
+ * Try to refill the TX DMA buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * 1 if we queued up a TX DMA buffer.
+ * 0 if we didn't want to handle this by DMA
+ * <0 on error
+ */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap)
+{
+ struct pl011_dmatx_data *dmatx = &uap->dmatx;
+ struct dma_chan *chan = dmatx->chan;
+ struct dma_device *dma_dev = chan->device;
+ struct dma_async_tx_descriptor *desc;
+ struct circ_buf *xmit = &uap->port.state->xmit;
+ unsigned int count;
+
+ /*
+ * Try to avoid the overhead involved in using DMA if the
+ * transaction fits in the first half of the FIFO, by using
+ * the standard interrupt handling. This ensures that we
+ * issue a uart_write_wakeup() at the appropriate time.
+ */
+ count = uart_circ_chars_pending(xmit);
+ if (count < (uap->fifosize >> 1)) {
+ uap->dmatx.queued = false;
+ return 0;
+ }
+
+ /*
+ * Bodge: don't send the last character by DMA, as this
+ * will prevent XON from notifying us to restart DMA.
+ */
+ count -= 1;
+
+ /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
+ if (count > PL011_DMA_BUFFER_SIZE)
+ count = PL011_DMA_BUFFER_SIZE;
+
+ if (xmit->tail < xmit->head)
+ memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
+ else {
+ size_t first = UART_XMIT_SIZE - xmit->tail;
+ size_t second = xmit->head;
+
+ memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
+ if (second)
+ memcpy(&dmatx->buf[first], &xmit->buf[0], second);
+ }
+
+ dmatx->sg.length = count;
+
+ if (dma_map_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE) != 1) {
+ uap->dmatx.queued = false;
+ dev_dbg(uap->port.dev, "unable to map TX DMA\n");
+ return -EBUSY;
+ }
+
+ desc = dma_dev->device_prep_slave_sg(chan, &dmatx->sg, 1, DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ dma_unmap_sg(dma_dev->dev, &dmatx->sg, 1, DMA_TO_DEVICE);
+ uap->dmatx.queued = false;
+ /*
+ * If DMA cannot be used right now, we complete this
+ * transaction via IRQ and let the TTY layer retry.
+ */
+ dev_dbg(uap->port.dev, "TX DMA busy\n");
+ return -EBUSY;
+ }
+
+ /* Some data to go along to the callback */
+ desc->callback = pl011_dma_tx_callback;
+ desc->callback_param = uap;
+
+ /* All errors should happen at prepare time */
+ dmaengine_submit(desc);
+
+ /* Fire the DMA transaction */
+ dma_dev->device_issue_pending(chan);
+
+ uap->dmacr |= UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+ uap->dmatx.queued = true;
+
+ /*
+ * Now we know that DMA will fire, so advance the ring buffer
+ * with the stuff we just dispatched.
+ */
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ uap->port.icount.tx += count;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uap->port);
+
+ return 1;
+}
+
+/*
+ * We received a transmit interrupt without a pending X-char but with
+ * pending characters.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * false if we want to use PIO to transmit
+ * true if we queued a DMA buffer
+ */
+static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+ if (!uap->using_dma)
+ return false;
+
+ /*
+ * If we already have a TX buffer queued, but received a
+ * TX interrupt, it will be because we've just sent an X-char.
+ * Ensure the TX DMA is enabled and the TX IRQ is disabled.
+ */
+ if (uap->dmatx.queued) {
+ uap->dmacr |= UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+ uap->im &= ~UART011_TXIM;
+ writew(uap->im, uap->port.membase + UART011_IMSC);
+ return true;
+ }
+
+ /*
+ * We don't have a TX buffer queued, so try to queue one.
+ * If we succesfully queued a buffer, mask the TX IRQ.
+ */
+ if (pl011_dma_tx_refill(uap) > 0) {
+ uap->im &= ~UART011_TXIM;
+ writew(uap->im, uap->port.membase + UART011_IMSC);
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Stop the DMA transmit (eg, due to received XOFF).
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+ if (uap->dmatx.queued) {
+ uap->dmacr &= ~UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+ }
+}
+
+/*
+ * Try to start a DMA transmit, or in the case of an XON/OFF
+ * character queued for send, try to get that character out ASAP.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * false if we want the TX IRQ to be enabled
+ * true if we have a buffer queued
+ */
+static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
+{
+ u16 dmacr;
+
+ if (!uap->using_dma)
+ return false;
+
+ if (!uap->port.x_char) {
+ /* no X-char, try to push chars out in DMA mode */
+ bool ret = true;
+
+ if (!uap->dmatx.queued) {
+ if (pl011_dma_tx_refill(uap) > 0) {
+ uap->im &= ~UART011_TXIM;
+ ret = true;
+ } else {
+ uap->im |= UART011_TXIM;
+ ret = false;
+ }
+ writew(uap->im, uap->port.membase + UART011_IMSC);
+ } else if (!(uap->dmacr & UART011_TXDMAE)) {
+ uap->dmacr |= UART011_TXDMAE;
+ writew(uap->dmacr,
+ uap->port.membase + UART011_DMACR);
+ }
+ return ret;
+ }
+
+ /*
+ * We have an X-char to send. Disable DMA to prevent it loading
+ * the TX fifo, and then see if we can stuff it into the FIFO.
+ */
+ dmacr = uap->dmacr;
+ uap->dmacr &= ~UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+
+ if (readw(uap->port.membase + UART01x_FR) & UART01x_FR_TXFF) {
+ /*
+ * No space in the FIFO, so enable the transmit interrupt
+ * so we know when there is space. Note that once we've
+ * loaded the character, we should just re-enable DMA.
+ */
+ return false;
+ }
+
+ writew(uap->port.x_char, uap->port.membase + UART01x_DR);
+ uap->port.icount.tx++;
+ uap->port.x_char = 0;
+
+ /* Success - restore the DMA state */
+ uap->dmacr = dmacr;
+ writew(dmacr, uap->port.membase + UART011_DMACR);
+
+ return true;
+}
+
+/*
+ * Flush the transmit buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static void pl011_dma_flush_buffer(struct uart_port *port)
+{
+ struct uart_amba_port *uap = (struct uart_amba_port *)port;
+
+ if (!uap->using_dma)
+ return;
+
+ /* Avoid deadlock with the DMA engine callback */
+ spin_unlock(&uap->port.lock);
+ dmaengine_terminate_all(uap->dmatx.chan);
+ spin_lock(&uap->port.lock);
+ if (uap->dmatx.queued) {
+ dma_unmap_sg(uap->dmatx.chan->device->dev, &uap->dmatx.sg, 1,
+ DMA_TO_DEVICE);
+ uap->dmatx.queued = false;
+ uap->dmacr &= ~UART011_TXDMAE;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+ }
+}
+
+
+static void pl011_dma_startup(struct uart_amba_port *uap)
+{
+ if (!uap->dmatx.chan)
+ return;
+
+ uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL);
+ if (!uap->dmatx.buf) {
+ dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
+ uap->port.fifosize = uap->fifosize;
+ return;
+ }
+
+ sg_init_one(&uap->dmatx.sg, uap->dmatx.buf, PL011_DMA_BUFFER_SIZE);
+
+ /* The DMA buffer is now the FIFO the TTY subsystem can use */
+ uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
+ uap->using_dma = true;
+
+ /* Turn on DMA error (RX/TX will be enabled on demand) */
+ uap->dmacr |= UART011_DMAONERR;
+ writew(uap->dmacr, uap->port.membase + UART011_DMACR);
+
+ /*
+ * ST Micro variants has some specific dma burst threshold
+ * compensation. Set this to 16 bytes, so burst will only
+ * be issued above/below 16 bytes.
+ */
+ if (uap->vendor->dma_threshold)
+ writew(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
+ uap->port.membase + ST_UART011_DMAWM);
+}
+
+static void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+ if (!uap->using_dma)
+ return;
+
+ /* Disable RX and TX DMA */
+ while (readw(uap->port.membase + UART01x_FR) & UART01x_FR_BUSY)
+ barrier();
+
+ spin_lock_irq(&uap->port.lock);
+ uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
+ 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;
+ }
+
+ kfree(uap->dmatx.buf);
+
+ uap->using_dma = false;
+}
+
+#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_remove(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_startup(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+ return false;
+}
+
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_start(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;
uap->im &= ~UART011_TXIM;
writew(uap->im, uap->port.membase + UART011_IMSC);
+ pl011_dma_tx_stop(uap);
}
static void pl011_start_tx(struct uart_port *port)
{
struct uart_amba_port *uap = (struct uart_amba_port *)port;
- uap->im |= UART011_TXIM;
- writew(uap->im, uap->port.membase + UART011_IMSC);
+ if (!pl011_dma_tx_start(uap)) {
+ uap->im |= UART011_TXIM;
+ writew(uap->im, uap->port.membase + UART011_IMSC);
+ }
}
static void pl011_stop_rx(struct uart_port *port)
return;
}
- count = uap->port.fifosize >> 1;
+ /* If we are using DMA mode, try to send some characters. */
+ if (pl011_dma_tx_irq(uap))
+ return;
+
+ count = uap->fifosize >> 1;
do {
writew(xmit->buf[xmit->tail], uap->port.membase + UART01x_DR);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
static irqreturn_t pl011_int(int irq, void *dev_id)
{
struct uart_amba_port *uap = dev_id;
+ unsigned long flags;
unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
int handled = 0;
- spin_lock(&uap->port.lock);
+ spin_lock_irqsave(&uap->port.lock, flags);
status = readw(uap->port.membase + UART011_MIS);
if (status) {
handled = 1;
}
- spin_unlock(&uap->port.lock);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
return IRQ_RETVAL(handled);
}
if (retval)
goto clk_dis;
- writew(uap->ifls, uap->port.membase + UART011_IFLS);
+ writew(uap->vendor->ifls, uap->port.membase + UART011_IFLS);
/*
* Provoke TX FIFO interrupt into asserting.
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);
+
/*
* initialise the old status of the modem signals
*/
uap->old_status = readw(uap->port.membase + UART01x_FR) & UART01x_FR_MODEM_ANY;
+ /* Startup DMA */
+ pl011_dma_startup(uap);
+
/*
* Finally, enable interrupts
*/
writew(0xffff, uap->port.membase + UART011_ICR);
spin_unlock_irq(&uap->port.lock);
+ pl011_dma_shutdown(uap);
+
/*
* Free the interrupt
*/
struct uart_amba_port *uap = (struct uart_amba_port *)port;
unsigned int lcr_h, old_cr;
unsigned long flags;
- unsigned int baud, quot;
+ unsigned int baud, quot, clkdiv;
+
+ if (uap->vendor->oversampling)
+ clkdiv = 8;
+ else
+ clkdiv = 16;
/*
* Ask the core to calculate the divisor for us.
*/
baud = uart_get_baud_rate(port, termios, old, 0,
- port->uartclk/(uap->oversampling ? 8 : 16));
+ port->uartclk / clkdiv);
if (baud > port->uartclk/16)
quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
if (!(termios->c_cflag & PARODD))
lcr_h |= UART01x_LCRH_EPS;
}
- if (port->fifosize > 1)
+ if (uap->fifosize > 1)
lcr_h |= UART01x_LCRH_FEN;
spin_lock_irqsave(&port->lock, flags);
uap->autorts = false;
}
- if (uap->oversampling) {
- if (baud > port->uartclk/16)
+ if (uap->vendor->oversampling) {
+ if (baud > port->uartclk / 16)
old_cr |= ST_UART011_CR_OVSFACT;
else
old_cr &= ~ST_UART011_CR_OVSFACT;
static const char *pl011_type(struct uart_port *port)
{
- return port->type == PORT_AMBA ? "AMBA/PL011" : NULL;
+ struct uart_amba_port *uap = (struct uart_amba_port *)port;
+ return uap->port.type == PORT_AMBA ? uap->type : NULL;
}
/*
.break_ctl = pl011_break_ctl,
.startup = pl011_startup,
.shutdown = pl011_shutdown,
+ .flush_buffer = pl011_dma_flush_buffer,
.set_termios = pl011_set_termios,
.type = pl011_type,
.release_port = pl010_release_port,
*baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
- if (uap->oversampling) {
+ if (uap->vendor->oversampling) {
if (readw(uap->port.membase + UART011_CR)
& ST_UART011_CR_OVSFACT)
*baud *= 2;
goto unmap;
}
- uap->ifls = vendor->ifls;
+ uap->vendor = vendor;
uap->lcrh_rx = vendor->lcrh_rx;
uap->lcrh_tx = vendor->lcrh_tx;
- uap->oversampling = vendor->oversampling;
+ uap->fifosize = vendor->fifosize;
uap->port.dev = &dev->dev;
uap->port.mapbase = dev->res.start;
uap->port.membase = base;
uap->port.iotype = UPIO_MEM;
uap->port.irq = dev->irq[0];
- uap->port.fifosize = vendor->fifosize;
+ uap->port.fifosize = uap->fifosize;
uap->port.ops = &amba_pl011_pops;
uap->port.flags = UPF_BOOT_AUTOCONF;
uap->port.line = i;
+ pl011_dma_probe(uap);
+
+ snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
amba_ports[i] = uap;
if (ret) {
amba_set_drvdata(dev, NULL);
amba_ports[i] = NULL;
+ pl011_dma_remove(uap);
clk_put(uap->clk);
unmap:
iounmap(base);
if (amba_ports[i] == uap)
amba_ports[i] = NULL;
+ pl011_dma_remove(uap);
iounmap(uap->port.membase);
clk_put(uap->clk);
kfree(uap);
projects / profile / ivi / kernel-adaptation-intel-automotive.git / commitdiff