[PATCH 27/48] ARM: PL08x: avoid duplicating registers in txd and phychan structures
Russell King - ARM Linux
linux at arm.linux.org.uk
Sun Jan 16 15:18:05 EST 2011
On Sun, Jan 16, 2011 at 12:03:33PM -0800, Dan Williams wrote:
> On 1/16/2011 11:59 AM, Russell King - ARM Linux wrote:
>> On Sun, Jan 16, 2011 at 11:56:08AM -0800, Dan Williams wrote:
>>> On Sun, Jan 16, 2011 at 4:36 AM, Russell King - ARM Linux
>>> <linux at arm.linux.org.uk> wrote:
>>>>>> That probably means you've got something out of order. I have them
>>>>>> ordered in my git tree, I'll recheck there.
>>>>>
>>>>> I rechecked here and I think everything is in order.
>>>>
>>>> Okay, something's screwed in the patch set - and I think I see what it is.
>>>> Patch 16 is missing a change. I'll respin.
>>>
>>> Can this be incremental to the previous series instead? I'm looking
>>> to get my 2.6.38 pull request submitted.
>>
>> In which case I don't know what state your tree in, so...
>
> Sorry, should have pointed that out, here it is:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx.git next
Hmm, I found the missing part in a follow-on patch. It should be safe
to apply but wasn't perfect so didn't get sent. (I thought it was a
little too noisy.)
Subject: [PATCH] ARM: PL08x: cleanup comments
Cleanup the formatting of comments, remove some which don't make sense
anymore.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/dma/amba-pl08x.c | 144 ++++++++++++++++----------------------------
include/linux/amba/pl08x.h | 45 +++++++-------
2 files changed, 72 insertions(+), 117 deletions(-)
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index bebc678..7b9c1b6 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -19,14 +19,14 @@
* this program; if not, write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
- * The full GNU General Public License is in this distribution in the
- * file called COPYING.
+ * The full GNU General Public License is in this distribution in the file
+ * called COPYING.
*
* Documentation: ARM DDI 0196G == PL080
- * Documentation: ARM DDI 0218E == PL081
+ * Documentation: ARM DDI 0218E == PL081
*
- * PL080 & PL081 both have 16 sets of DMA signals that can be routed to
- * any channel.
+ * PL080 & PL081 both have 16 sets of DMA signals that can be routed to any
+ * channel.
*
* The PL080 has 8 channels available for simultaneous use, and the PL081
* has only two channels. So on these DMA controllers the number of channels
@@ -91,11 +91,9 @@
#define DRIVER_NAME "pl08xdmac"
/**
- * struct vendor_data - vendor-specific config parameters
- * for PL08x derivatives
+ * struct vendor_data - vendor-specific config parameters for PL08x derivatives
* @channels: the number of channels available in this variant
- * @dualmaster: whether this version supports dual AHB masters
- * or not.
+ * @dualmaster: whether this version supports dual AHB masters or not.
*/
struct vendor_data {
u8 channels;
@@ -241,10 +239,8 @@ static void pl08x_start_txd(struct pl08x_dma_chan *plchan,
*
* Disabling individual channels could lose data.
*
- * Disable the peripheral DMA after disabling the DMAC
- * in order to allow the DMAC FIFO to drain, and
- * hence allow the channel to show inactive
- *
+ * Disable the peripheral DMA after disabling the DMAC in order to allow
+ * the DMAC FIFO to drain, and hence allow the channel to show inactive
*/
static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
{
@@ -367,6 +363,10 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
/*
* Allocate a physical channel for a virtual channel
+ *
+ * Try to locate a physical channel to be used for this transfer. If all
+ * are taken return NULL and the requester will have to cope by using
+ * some fallback PIO mode or retrying later.
*/
static struct pl08x_phy_chan *
pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
@@ -376,12 +376,6 @@ pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
unsigned long flags;
int i;
- /*
- * Try to locate a physical channel to be used for
- * this transfer. If all are taken return NULL and
- * the requester will have to cope by using some fallback
- * PIO mode or retrying later.
- */
for (i = 0; i < pl08x->vd->channels; i++) {
ch = &pl08x->phy_chans[i];
@@ -495,9 +489,9 @@ struct pl08x_lli_build_data {
};
/*
- * Autoselect a master bus to use for the transfer
- * this prefers the destination bus if both available
- * if fixed address on one bus the other will be chosen
+ * Autoselect a master bus to use for the transfer this prefers the
+ * destination bus if both available if fixed address on one bus the
+ * other will be chosen
*/
static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
struct pl08x_bus_data **mbus, struct pl08x_bus_data **sbus, u32 cctl)
@@ -530,8 +524,7 @@ static void pl08x_choose_master_bus(struct pl08x_lli_build_data *bd,
}
/*
- * Fills in one LLI for a certain transfer descriptor
- * and advance the counter
+ * Fills in one LLI for a certain transfer descriptor and advance the counter
*/
static void pl08x_fill_lli_for_desc(struct pl08x_lli_build_data *bd,
int num_llis, int len, u32 cctl)
@@ -640,15 +633,11 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
* Choose bus to align to
* - prefers destination bus if both available
* - if fixed address on one bus chooses other
- * - modifies cctl to choose an appropriate master
*/
pl08x_choose_master_bus(&bd, &mbus, &sbus, cctl);
if (txd->len < mbus->buswidth) {
- /*
- * Less than a bus width available
- * - send as single bytes
- */
+ /* Less than a bus width available - send as single bytes */
while (bd.remainder) {
dev_vdbg(&pl08x->adev->dev,
"%s single byte LLIs for a transfer of "
@@ -659,10 +648,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
total_bytes++;
}
} else {
- /*
- * Make one byte LLIs until master bus is aligned
- * - slave will then be aligned also
- */
+ /* Make one byte LLIs until master bus is aligned */
while ((mbus->addr) % (mbus->buswidth)) {
dev_vdbg(&pl08x->adev->dev,
"%s adjustment lli for less than bus width "
@@ -674,7 +660,7 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
}
/*
- * Master now aligned
+ * Master now aligned
* - if slave is not then we must set its width down
*/
if (sbus->addr % sbus->buswidth) {
@@ -732,10 +718,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
if (lli_len == target_len) {
/*
- * Can send what we wanted
- */
- /*
- * Maintain alignment
+ * Can send what we wanted.
+ * Maintain alignment
*/
lli_len = (lli_len/mbus->buswidth) *
mbus->buswidth;
@@ -743,17 +727,14 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
} else {
/*
* So now we know how many bytes to transfer
- * to get to the nearest boundary
- * The next LLI will past the boundary
- * - however we may be working to a boundary
- * on the slave bus
- * We need to ensure the master stays aligned
+ * to get to the nearest boundary. The next
+ * LLI will past the boundary. However, we
+ * may be working to a boundary on the slave
+ * bus. We need to ensure the master stays
+ * aligned, and that we are working in
+ * multiples of the bus widths.
*/
odd_bytes = lli_len % mbus->buswidth;
- /*
- * - and that we are working in multiples
- * of the bus widths
- */
lli_len -= odd_bytes;
}
@@ -793,8 +774,8 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
if (odd_bytes) {
/*
- * Creep past the boundary,
- * maintaining master alignment
+ * Creep past the boundary, maintaining
+ * master alignment
*/
int j;
for (j = 0; (j < mbus->buswidth)
@@ -837,13 +818,9 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
}
llis_va = txd->llis_va;
- /*
- * The final LLI terminates the LLI.
- */
+ /* The final LLI terminates the LLI. */
llis_va[num_llis - 1].lli = 0;
- /*
- * The final LLI element shall also fire an interrupt
- */
+ /* The final LLI element shall also fire an interrupt. */
llis_va[num_llis - 1].cctl |= PL080_CONTROL_TC_IRQ_EN;
#ifdef VERBOSE_DEBUG
@@ -891,7 +868,6 @@ static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,
list_del(&txdi->node);
pl08x_free_txd(pl08x, txdi);
}
-
}
}
@@ -1020,10 +996,9 @@ static struct dma_async_tx_descriptor *pl08x_prep_dma_interrupt(
}
/*
- * Code accessing dma_async_is_complete() in a tight loop
- * may give problems - could schedule where indicated.
- * If slaves are relying on interrupts to signal completion this
- * function must not be called with interrupts disabled
+ * Code accessing dma_async_is_complete() in a tight loop may give problems.
+ * If slaves are relying on interrupts to signal completion this function
+ * must not be called with interrupts disabled.
*/
static enum dma_status
pl08x_dma_tx_status(struct dma_chan *chan,
@@ -1046,10 +1021,6 @@ pl08x_dma_tx_status(struct dma_chan *chan,
}
/*
- * schedule(); could be inserted here
- */
-
- /*
* This cookie not complete yet
*/
last_used = plchan->chan.cookie;
@@ -1273,11 +1244,10 @@ static int pl08x_prep_channel_resources(struct pl08x_dma_chan *plchan,
}
} else
/*
- * Else we're all set, paused and ready to roll,
- * status will switch to PL08X_CHAN_RUNNING when
- * we call issue_pending(). If there is something
- * running on the channel already we don't change
- * its state.
+ * Else we're all set, paused and ready to roll, status
+ * will switch to PL08X_CHAN_RUNNING when we call
+ * issue_pending(). If there is something running on the
+ * channel already we don't change its state.
*/
if (plchan->state == PL08X_CHAN_IDLE)
plchan->state = PL08X_CHAN_PAUSED;
@@ -1528,10 +1498,9 @@ bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
/*
* Just check that the device is there and active
- * TODO: turn this bit on/off depending on the number of
- * physical channels actually used, if it is zero... well
- * shut it off. That will save some power. Cut the clock
- * at the same time.
+ * TODO: turn this bit on/off depending on the number of physical channels
+ * actually used, if it is zero... well shut it off. That will save some
+ * power. Cut the clock at the same time.
*/
static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
{
@@ -1579,16 +1548,11 @@ static void pl08x_tasklet(unsigned long data)
plchan->at = NULL;
if (txd) {
- /*
- * Update last completed
- */
+ /* Update last completed */
plchan->lc = txd->tx.cookie;
}
- /*
- * If a new descriptor is queued, set it up
- * plchan->at is NULL here
- */
+ /* If a new descriptor is queued, set it up plchan->at is NULL here */
if (!list_empty(&plchan->pend_list)) {
struct pl08x_txd *next;
@@ -1615,11 +1579,10 @@ static void pl08x_tasklet(unsigned long data)
plchan->state = PL08X_CHAN_IDLE;
/*
- * And NOW before anyone else can grab that free:d
- * up physical channel, see if there is some memcpy
- * pending that seriously needs to start because of
- * being stacked up while we were choking the
- * physical channels with data.
+ * And NOW before anyone else can grab that free:d up
+ * physical channel, see if there is some memcpy pending
+ * that seriously needs to start because of being stacked
+ * up while we were choking the physical channels with data.
*/
list_for_each_entry(waiting, &pl08x->memcpy.channels,
chan.device_node) {
@@ -1670,9 +1633,7 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
val = readl(pl08x->base + PL080_ERR_STATUS);
if (val) {
- /*
- * An error interrupt (on one or more channels)
- */
+ /* An error interrupt (on one or more channels) */
dev_err(&pl08x->adev->dev,
"%s error interrupt, register value 0x%08x\n",
__func__, val);
@@ -1696,9 +1657,7 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
mask |= (1 << i);
}
}
- /*
- * Clear only the terminal interrupts on channels we processed
- */
+ /* Clear only the terminal interrupts on channels we processed */
writel(mask, pl08x->base + PL080_TC_CLEAR);
return mask ? IRQ_HANDLED : IRQ_NONE;
@@ -1717,6 +1676,7 @@ static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
int i;
INIT_LIST_HEAD(&dmadev->channels);
+
/*
* Register as many many memcpy as we have physical channels,
* we won't always be able to use all but the code will have
@@ -1950,9 +1910,7 @@ static int pl08x_probe(struct amba_device *adev, struct amba_id *id)
/* Turn on the PL08x */
pl08x_ensure_on(pl08x);
- /*
- * Attach the interrupt handler
- */
+ /* Attach the interrupt handler */
writel(0x000000FF, pl08x->base + PL080_ERR_CLEAR);
writel(0x000000FF, pl08x->base + PL080_TC_CLEAR);
diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h
index 933b4ed..3111385 100644
--- a/include/linux/amba/pl08x.h
+++ b/include/linux/amba/pl08x.h
@@ -12,7 +12,6 @@
*
* Please credit ARM.com
* Documentation: ARM DDI 0196D
- *
*/
#ifndef AMBA_PL08X_H
@@ -55,8 +54,8 @@ enum {
* @circular_buffer: whether the buffer passed in is circular and
* shall simply be looped round round (like a record baby round
* round round round)
- * @single: the device connected to this channel will request single
- * DMA transfers, not bursts. (Bursts are default.)
+ * @single: the device connected to this channel will request single DMA
+ * transfers, not bursts. (Bursts are default.)
* @periph_buses: the device connected to this channel is accessible via
* these buses (use PL08X_AHB1 | PL08X_AHB2).
*/
@@ -78,8 +77,7 @@ struct pl08x_channel_data {
* @addr: current address
* @maxwidth: the maximum width of a transfer on this bus
* @buswidth: the width of this bus in bytes: 1, 2 or 4
- * @fill_bytes: bytes required to fill to the next bus memory
- * boundary
+ * @fill_bytes: bytes required to fill to the next bus memory boundary
*/
struct pl08x_bus_data {
dma_addr_t addr;
@@ -92,10 +90,10 @@ struct pl08x_bus_data {
* struct pl08x_phy_chan - holder for the physical channels
* @id: physical index to this channel
* @lock: a lock to use when altering an instance of this struct
- * @signal: the physical signal (aka channel) serving this
- * physical channel right now
- * @serving: the virtual channel currently being served by this
- * physical channel
+ * @signal: the physical signal (aka channel) serving this physical channel
+ * right now
+ * @serving: the virtual channel currently being served by this physical
+ * channel
*/
struct pl08x_phy_chan {
unsigned int id;
@@ -118,8 +116,7 @@ struct pl08x_txd {
dma_addr_t dst_addr;
size_t len;
dma_addr_t llis_bus;
- void *llis_va;
- bool active;
+ struct pl08x_lli *llis_va;
/* Default cctl value for LLIs */
u32 cctl;
/*
@@ -130,8 +127,8 @@ struct pl08x_txd {
};
/**
- * struct pl08x_dma_chan_state - holds the PL08x specific virtual
- * channel states
+ * struct pl08x_dma_chan_state - holds the PL08x specific virtual channel
+ * states
* @PL08X_CHAN_IDLE: the channel is idle
* @PL08X_CHAN_RUNNING: the channel has allocated a physical transport
* channel and is running a transfer on it
@@ -152,7 +149,7 @@ enum pl08x_dma_chan_state {
* @chan: wrappped abstract channel
* @phychan: the physical channel utilized by this channel, if there is one
* @phychan_hold: if non-zero, hold on to the physical channel even if we
- * have no pending entries
+ * have no pending entries
* @tasklet: tasklet scheduled by the IRQ to handle actual work etc
* @name: name of channel
* @cd: channel platform data
@@ -166,8 +163,8 @@ enum pl08x_dma_chan_state {
* @host: a pointer to the host (internal use)
* @state: whether the channel is idle, paused, running etc
* @slave: whether this channel is a device (slave) or for memcpy
- * @waiting: a TX descriptor on this channel which is waiting for
- * a physical channel to become available
+ * @waiting: a TX descriptor on this channel which is waiting for a physical
+ * channel to become available
*/
struct pl08x_dma_chan {
struct dma_chan chan;
@@ -189,16 +186,16 @@ struct pl08x_dma_chan {
};
/**
- * struct pl08x_platform_data - the platform configuration for the
- * PL08x PrimeCells.
+ * struct pl08x_platform_data - the platform configuration for the PL08x
+ * PrimeCells.
* @slave_channels: the channels defined for the different devices on the
* platform, all inclusive, including multiplexed channels. The available
- * physical channels will be multiplexed around these signals as they
- * are requested, just enumerate all possible channels.
- * @get_signal: request a physical signal to be used for a DMA
- * transfer immediately: if there is some multiplexing or similar blocking
- * the use of the channel the transfer can be denied by returning
- * less than zero, else it returns the allocated signal number
+ * physical channels will be multiplexed around these signals as they are
+ * requested, just enumerate all possible channels.
+ * @get_signal: request a physical signal to be used for a DMA transfer
+ * immediately: if there is some multiplexing or similar blocking the use
+ * of the channel the transfer can be denied by returning less than zero,
+ * else it returns the allocated signal number
* @put_signal: indicate to the platform that this physical signal is not
* running any DMA transfer and multiplexing can be recycled
* @lli_buses: buses which LLIs can be fetched from: PL08X_AHB1 | PL08X_AHB2
--
1.6.2.5
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