OpenE2K
/
linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Merge branches 'mmci' and 'pl011-dma' into devel

This commit is contained in:
Russell King 2011-01-05 18:08:31 +00:00
parent 31edf274f9 8c11a94d86 38d624361b
commit aa312be198
4 changed files with 769 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

207
drivers/mmc/host/mmci.c
View File

@ -19,6 +19,7 @@
#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>
@ -45,6 +46,12 @@ static unsigned int fmax = 515633;
* 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;
@ -52,6 +59,10 @@ struct variant_data {
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 = {
@ -65,6 +76,8 @@ static struct variant_data variant_u300 = {
.fifohalfsize = 8 * 4,
.clkreg_enable = 1 << 13, /* HWFCEN */
.datalength_bits = 16,
.broken_blockend_dma = true,
.sdio = true,
};
static struct variant_data variant_ux500 = {
@ -73,7 +86,11 @@ 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
*/
@ -86,7 +103,22 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
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;
@ -129,10 +161,26 @@ mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
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;
}
@ -162,6 +210,8 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
host->data = data;
host->size = data->blksz * data->blocks;
host->data_xfered = 0;
host->blockend = false;
host->dataend = false;
mmci_init_sg(host, data);
@ -196,9 +246,14 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *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
@ -233,20 +288,9 @@ 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)
@ -255,7 +299,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
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
@ -273,9 +320,64 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *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 {
@ -356,7 +458,32 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem
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;
@ -437,7 +564,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
* "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
@ -446,7 +573,7 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
* 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);
}
@ -469,6 +596,14 @@ static irqreturn_t mmci_irq(int irq, void *dev_id)
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);
@ -635,6 +770,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
struct variant_data *variant = id->data;
struct mmci_host *host;
struct mmc_host *mmc;
unsigned int mask;
int ret;
/* must have platform data */
@ -806,20 +942,30 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id)
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;
writel(mask, host->base + MMCIMASK0);
amba_set_drvdata(dev, mmc);
mmc_add_host(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:
@ -864,7 +1010,8 @@ static int __devexit mmci_remove(struct amba_device *dev)
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);

9
drivers/mmc/host/mmci.h
View File

@ -139,6 +139,11 @@
MCI_DATATIMEOUTMASK|MCI_TXUNDERRUNMASK|MCI_RXOVERRUNMASK| \
MCI_CMDRESPENDMASK|MCI_CMDSENTMASK|MCI_DATABLOCKENDMASK)
/* These interrupts are directed to IRQ1 when two IRQ lines are available */
#define MCI_IRQ1MASK \
(MCI_RXFIFOHALFFULLMASK | MCI_RXDATAAVLBLMASK | \
MCI_TXFIFOHALFEMPTYMASK)
#define NR_SG 16
struct clk;
@ -154,6 +159,7 @@ struct mmci_host {
int gpio_cd;
int gpio_wp;
int gpio_cd_irq;
bool singleirq;
unsigned int data_xfered;
@ -171,6 +177,9 @@ struct mmci_host {
struct timer_list timer;
unsigned int oldstat;
bool blockend;
bool dataend;
/* pio stuff */
struct sg_mapping_iter sg_miter;
unsigned int size;

592
drivers/serial/amba-pl011.c
View File

@ -7,6 +7,7 @@
*
* 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
@ -48,6 +49,9 @@
#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>
@ -63,21 +67,6 @@
#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;
@ -85,6 +74,7 @@ struct vendor_data {
unsigned int lcrh_tx;
unsigned int lcrh_rx;
bool oversampling;
bool dma_threshold;
};
static struct vendor_data vendor_arm = {
@ -93,6 +83,7 @@ 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 = {
@ -101,22 +92,535 @@ 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)
@ -203,7 +707,11 @@ static void pl011_tx_chars(struct uart_amba_port *uap)
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);
@ -246,10 +754,11 @@ static void pl011_modem_status(struct uart_amba_port *uap)
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) {
@ -274,7 +783,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
handled = 1;
}
spin_unlock(&uap->port.lock);
spin_unlock_irqrestore(&uap->port.lock, flags);
return IRQ_RETVAL(handled);
}
@ -396,7 +905,7 @@ static int pl011_startup(struct uart_port *port)
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.
@ -423,11 +932,18 @@ static int pl011_startup(struct uart_port *port)
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
*/
@ -467,6 +983,8 @@ static void pl011_shutdown(struct uart_port *port)
writew(0xffff, uap->port.membase + UART011_ICR);
spin_unlock_irq(&uap->port.lock);
pl011_dma_shutdown(uap);
/*
* Free the interrupt
*/
@ -498,13 +1016,18 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
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);
@ -532,7 +1055,7 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
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);
@ -588,8 +1111,8 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
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;
@ -622,7 +1145,8 @@ pl011_set_termios(struct uart_port *port, struct ktermios *termios,
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;
}
/*
@ -679,6 +1203,7 @@ static struct uart_ops amba_pl011_pops = {
.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,
@ -761,7 +1286,7 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud,
*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;
@ -858,19 +1383,22 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
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;
@ -879,6 +1407,7 @@ static int pl011_probe(struct amba_device *dev, struct amba_id *id)
if (ret) {
amba_set_drvdata(dev, NULL);
amba_ports[i] = NULL;
pl011_dma_remove(uap);
clk_put(uap->clk);
unmap:
iounmap(base);
@ -902,6 +1431,7 @@ static int pl011_remove(struct amba_device *dev)
if (amba_ports[i] == uap)
amba_ports[i] = NULL;
pl011_dma_remove(uap);
iounmap(uap->port.membase);
clk_put(uap->clk);
kfree(uap);

22
include/linux/amba/serial.h
View File

@ -113,6 +113,21 @@
#define UART01x_LCRH_PEN 0x02
#define UART01x_LCRH_BRK 0x01
#define ST_UART011_DMAWM_RX_1 (0 << 3)
#define ST_UART011_DMAWM_RX_2 (1 << 3)
#define ST_UART011_DMAWM_RX_4 (2 << 3)
#define ST_UART011_DMAWM_RX_8 (3 << 3)
#define ST_UART011_DMAWM_RX_16 (4 << 3)
#define ST_UART011_DMAWM_RX_32 (5 << 3)
#define ST_UART011_DMAWM_RX_48 (6 << 3)
#define ST_UART011_DMAWM_TX_1 0
#define ST_UART011_DMAWM_TX_2 1
#define ST_UART011_DMAWM_TX_4 2
#define ST_UART011_DMAWM_TX_8 3
#define ST_UART011_DMAWM_TX_16 4
#define ST_UART011_DMAWM_TX_32 5
#define ST_UART011_DMAWM_TX_48 6
#define UART010_IIR_RTIS 0x08
#define UART010_IIR_TIS 0x04
#define UART010_IIR_RIS 0x02
@ -180,6 +195,13 @@ struct amba_device; /* in uncompress this is included but amba/bus.h is not */
struct amba_pl010_data {
void (*set_mctrl)(struct amba_device *dev, void __iomem *base, unsigned int mctrl);
};
struct dma_chan;
struct amba_pl011_data {
bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
void *dma_rx_param;
void *dma_tx_param;
};
#endif
#endif