diff options
Diffstat (limited to 'drivers/dma/apbh_dma.c')
| -rw-r--r-- | drivers/dma/apbh_dma.c | 211 |
1 files changed, 51 insertions, 160 deletions
diff --git a/drivers/dma/apbh_dma.c b/drivers/dma/apbh_dma.c index 69a1042..e85f5fe 100644 --- a/drivers/dma/apbh_dma.c +++ b/drivers/dma/apbh_dma.c @@ -53,6 +53,47 @@ int mxs_dma_validate_chan(int channel) } /* + * Return the address of the command within a descriptor. + */ +static unsigned int mxs_dma_cmd_address(struct mxs_dma_desc *desc) +{ + return desc->address + offsetof(struct mxs_dma_desc, cmd); +} + +/* + * Read a DMA channel's hardware semaphore. + * + * As used by the MXS platform's DMA software, the DMA channel's hardware + * semaphore reflects the number of DMA commands the hardware will process, but + * has not yet finished. This is a volatile value read directly from hardware, + * so it must be be viewed as immediately stale. + * + * If the channel is not marked busy, or has finished processing all its + * commands, this value should be zero. + * + * See mxs_dma_append() for details on how DMA command blocks must be configured + * to maintain the expected behavior of the semaphore's value. + */ +static int mxs_dma_read_semaphore(int channel) +{ + struct mx28_apbh_regs *apbh_regs = + (struct mx28_apbh_regs *)MXS_APBH_BASE; + uint32_t tmp; + int ret; + + ret = mxs_dma_validate_chan(channel); + if (ret) + return ret; + + tmp = readl(&apbh_regs->ch[channel].hw_apbh_ch_sema); + + tmp &= APBH_CHn_SEMA_PHORE_MASK; + tmp >>= APBH_CHn_SEMA_PHORE_OFFSET; + + return tmp; +} + +/* * Enable a DMA channel. * * If the given channel has any DMA descriptors on its active list, this @@ -61,7 +102,7 @@ int mxs_dma_validate_chan(int channel) * This function marks the DMA channel as "busy," whether or not there are any * descriptors to process. */ -int mxs_dma_enable(int channel) +static int mxs_dma_enable(int channel) { struct mx28_apbh_regs *apbh_regs = (struct mx28_apbh_regs *)MXS_APBH_BASE; @@ -132,7 +173,7 @@ int mxs_dma_enable(int channel) * state. It is unwise to call this function if there is ANY chance the hardware * is still processing a command. */ -int mxs_dma_disable(int channel) +static int mxs_dma_disable(int channel) { struct mxs_dma_chan *pchan; struct mx28_apbh_regs *apbh_regs = @@ -162,7 +203,7 @@ int mxs_dma_disable(int channel) /* * Resets the DMA channel hardware. */ -int mxs_dma_reset(int channel) +static int mxs_dma_reset(int channel) { struct mx28_apbh_regs *apbh_regs = (struct mx28_apbh_regs *)MXS_APBH_BASE; @@ -179,90 +220,11 @@ int mxs_dma_reset(int channel) } /* - * Freeze a DMA channel. - * - * This function causes the channel to continuously fail arbitration for bus - * access, which halts all forward progress without losing any state. A call to - * mxs_dma_unfreeze() will cause the channel to continue its current operation - * with no ill effect. - */ -int mxs_dma_freeze(int channel) -{ - struct mx28_apbh_regs *apbh_regs = - (struct mx28_apbh_regs *)MXS_APBH_BASE; - int ret; - - ret = mxs_dma_validate_chan(channel); - if (ret) - return ret; - - writel(1 << (channel + APBH_CHANNEL_CTRL_FREEZE_CHANNEL_OFFSET), - &apbh_regs->hw_apbh_channel_ctrl_set); - - return 0; -} - -/* - * Unfreeze a DMA channel. - * - * This function reverses the effect of mxs_dma_freeze(), enabling the DMA - * channel to continue from where it was frozen. - */ -int mxs_dma_unfreeze(int channel) -{ - struct mx28_apbh_regs *apbh_regs = - (struct mx28_apbh_regs *)MXS_APBH_BASE; - int ret; - - ret = mxs_dma_validate_chan(channel); - if (ret) - return ret; - - writel(1 << (channel + APBH_CHANNEL_CTRL_FREEZE_CHANNEL_OFFSET), - &apbh_regs->hw_apbh_channel_ctrl_clr); - - return 0; -} - -/* - * Read a DMA channel's hardware semaphore. - * - * As used by the MXS platform's DMA software, the DMA channel's hardware - * semaphore reflects the number of DMA commands the hardware will process, but - * has not yet finished. This is a volatile value read directly from hardware, - * so it must be be viewed as immediately stale. - * - * If the channel is not marked busy, or has finished processing all its - * commands, this value should be zero. - * - * See mxs_dma_append() for details on how DMA command blocks must be configured - * to maintain the expected behavior of the semaphore's value. - */ -int mxs_dma_read_semaphore(int channel) -{ - struct mx28_apbh_regs *apbh_regs = - (struct mx28_apbh_regs *)MXS_APBH_BASE; - uint32_t tmp; - int ret; - - ret = mxs_dma_validate_chan(channel); - if (ret) - return ret; - - tmp = readl(&apbh_regs->ch[channel].hw_apbh_ch_sema); - - tmp &= APBH_CHn_SEMA_PHORE_MASK; - tmp >>= APBH_CHn_SEMA_PHORE_OFFSET; - - return tmp; -} - -/* * Enable or disable DMA interrupt. * * This function enables the given DMA channel to interrupt the CPU. */ -int mxs_dma_enable_irq(int channel, int enable) +static int mxs_dma_enable_irq(int channel, int enable) { struct mx28_apbh_regs *apbh_regs = (struct mx28_apbh_regs *)MXS_APBH_BASE; @@ -283,32 +245,12 @@ int mxs_dma_enable_irq(int channel, int enable) } /* - * Check if a DMA interrupt is pending. - */ -int mxs_dma_irq_is_pending(int channel) -{ - struct mx28_apbh_regs *apbh_regs = - (struct mx28_apbh_regs *)MXS_APBH_BASE; - uint32_t tmp; - int ret; - - ret = mxs_dma_validate_chan(channel); - if (ret) - return ret; - - tmp = readl(&apbh_regs->hw_apbh_ctrl1); - tmp |= readl(&apbh_regs->hw_apbh_ctrl2); - - return (tmp >> channel) & 1; -} - -/* * Clear DMA interrupt. * * The software that is using the DMA channel must register to receive its * interrupts and, when they arrive, must call this function to clear them. */ -int mxs_dma_ack_irq(int channel) +static int mxs_dma_ack_irq(int channel) { struct mx28_apbh_regs *apbh_regs = (struct mx28_apbh_regs *)MXS_APBH_BASE; @@ -327,7 +269,7 @@ int mxs_dma_ack_irq(int channel) /* * Request to reserve a DMA channel */ -int mxs_dma_request(int channel) +static int mxs_dma_request(int channel) { struct mxs_dma_chan *pchan; @@ -359,7 +301,7 @@ int mxs_dma_request(int channel) * The channel will NOT be released if it's marked "busy" (see * mxs_dma_enable()). */ -int mxs_dma_release(int channel) +static int mxs_dma_release(int channel) { struct mxs_dma_chan *pchan; int ret; @@ -411,32 +353,6 @@ void mxs_dma_desc_free(struct mxs_dma_desc *pdesc) } /* - * Return the address of the command within a descriptor. - */ -unsigned int mxs_dma_cmd_address(struct mxs_dma_desc *desc) -{ - return desc->address + offsetof(struct mxs_dma_desc, cmd); -} - -/* - * Check if descriptor is on a channel's active list. - * - * This function returns the state of a descriptor's "ready" flag. This flag is - * usually set only if the descriptor appears on a channel's active list. The - * descriptor may or may not have already been processed by the hardware. - * - * The "ready" flag is set when the descriptor is submitted to a channel by a - * call to mxs_dma_append() or mxs_dma_append_list(). The "ready" flag is - * cleared when a processed descriptor is moved off the active list by a call - * to mxs_dma_finish(). The "ready" flag is NOT cleared if the descriptor is - * aborted by a call to mxs_dma_disable(). - */ -int mxs_dma_desc_pending(struct mxs_dma_desc *pdesc) -{ - return pdesc->flags & MXS_DMA_DESC_READY; -} - -/* * Add a DMA descriptor to a channel. * * If the descriptor list for this channel is not empty, this function sets the @@ -509,31 +425,6 @@ int mxs_dma_desc_append(int channel, struct mxs_dma_desc *pdesc) } /* - * Retrieve processed DMA descriptors. - * - * This function moves all the descriptors from the DMA channel's "done" list to - * the head of the given list. - */ -int mxs_dma_get_finished(int channel, struct list_head *head) -{ - struct mxs_dma_chan *pchan; - int ret; - - ret = mxs_dma_validate_chan(channel); - if (ret) - return ret; - - if (head == NULL) - return 0; - - pchan = mxs_dma_channels + channel; - - list_splice(&pchan->done, head); - - return 0; -} - -/* * Clean up processed DMA descriptors. * * This function removes processed DMA descriptors from the "active" list. Pass @@ -544,7 +435,7 @@ int mxs_dma_get_finished(int channel, struct list_head *head) * This function marks the DMA channel as "not busy" if no unprocessed * descriptors remain on the "active" list. */ -int mxs_dma_finish(int channel, struct list_head *head) +static int mxs_dma_finish(int channel, struct list_head *head) { int sem; struct mxs_dma_chan *pchan; @@ -590,7 +481,7 @@ int mxs_dma_finish(int channel, struct list_head *head) /* * Wait for DMA channel to complete */ -int mxs_dma_wait_complete(uint32_t timeout, unsigned int chan) +static int mxs_dma_wait_complete(uint32_t timeout, unsigned int chan) { struct mx28_apbh_regs *apbh_regs = (struct mx28_apbh_regs *)MXS_APBH_BASE; @@ -606,7 +497,7 @@ int mxs_dma_wait_complete(uint32_t timeout, unsigned int chan) mxs_dma_reset(chan); } - return 0; + return ret; } /* |