diff options
| -rw-r--r-- | drivers/dma/amba-pl08x.c | 146 | ||||
| -rw-r--r-- | include/linux/amba/pl08x.h | 43 |
2 files changed, 72 insertions, 117 deletions
diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c index bebc678ed4f..297f48b0cba 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 5b87b6aac3f..3111385b8ca 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; @@ -119,7 +117,6 @@ struct pl08x_txd { size_t len; dma_addr_t llis_bus; struct pl08x_lli *llis_va; - bool active; /* 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 |