diff options
Diffstat (limited to 'arch/blackfin')
| -rw-r--r-- | arch/blackfin/include/asm/dma.h | 17 | ||||
| -rw-r--r-- | arch/blackfin/kernel/bfin_dma_5xx.c | 31 |
2 files changed, 13 insertions, 35 deletions
diff --git a/arch/blackfin/include/asm/dma.h b/arch/blackfin/include/asm/dma.h index c9a59622e23..e3c0dfa73d1 100644 --- a/arch/blackfin/include/asm/dma.h +++ b/arch/blackfin/include/asm/dma.h @@ -10,6 +10,7 @@ #include <linux/interrupt.h> #include <mach/dma.h> +#include <asm/atomic.h> #include <asm/blackfin.h> #include <asm/page.h> @@ -19,11 +20,6 @@ * Generic DMA Declarations * ****************************************************************************/ -enum dma_chan_status { - DMA_CHANNEL_FREE, - DMA_CHANNEL_REQUESTED, - DMA_CHANNEL_ENABLED, -}; /*------------------------- * config reg bits value @@ -104,11 +100,9 @@ struct dma_register { }; -struct mutex; struct dma_channel { - struct mutex dmalock; const char *device_id; - enum dma_chan_status chan_status; + atomic_t chan_status; volatile struct dma_register *regs; struct dmasg *sg; /* large mode descriptor */ unsigned int irq; @@ -220,24 +214,19 @@ static inline void set_dma_sg(unsigned int channel, struct dmasg *sg, int ndsize static inline int dma_channel_active(unsigned int channel) { - if (dma_ch[channel].chan_status == DMA_CHANNEL_FREE) - return 0; - else - return 1; + return atomic_read(&dma_ch[channel].chan_status); } static inline void disable_dma(unsigned int channel) { dma_ch[channel].regs->cfg &= ~DMAEN; SSYNC(); - dma_ch[channel].chan_status = DMA_CHANNEL_REQUESTED; } static inline void enable_dma(unsigned int channel) { dma_ch[channel].regs->curr_x_count = 0; dma_ch[channel].regs->curr_y_count = 0; dma_ch[channel].regs->cfg |= DMAEN; - dma_ch[channel].chan_status = DMA_CHANNEL_ENABLED; } void free_dma(unsigned int channel); int request_dma(unsigned int channel, const char *device_id); diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c index 3946aff4f41..639dcee5611 100644 --- a/arch/blackfin/kernel/bfin_dma_5xx.c +++ b/arch/blackfin/kernel/bfin_dma_5xx.c @@ -37,9 +37,8 @@ static int __init blackfin_dma_init(void) printk(KERN_INFO "Blackfin DMA Controller\n"); for (i = 0; i < MAX_DMA_CHANNELS; i++) { - dma_ch[i].chan_status = DMA_CHANNEL_FREE; + atomic_set(&dma_ch[i].chan_status, 0); dma_ch[i].regs = dma_io_base_addr[i]; - mutex_init(&(dma_ch[i].dmalock)); } /* Mark MEMDMA Channel 0 as requested since we're using it internally */ request_dma(CH_MEM_STREAM0_DEST, "Blackfin dma_memcpy"); @@ -60,7 +59,7 @@ static int proc_dma_show(struct seq_file *m, void *v) int i; for (i = 0; i < MAX_DMA_CHANNELS; ++i) - if (dma_ch[i].chan_status != DMA_CHANNEL_FREE) + if (dma_channel_active(i)) seq_printf(m, "%2d: %s\n", i, dma_ch[i].device_id); return 0; @@ -107,20 +106,11 @@ int request_dma(unsigned int channel, const char *device_id) } #endif - mutex_lock(&(dma_ch[channel].dmalock)); - - if ((dma_ch[channel].chan_status == DMA_CHANNEL_REQUESTED) - || (dma_ch[channel].chan_status == DMA_CHANNEL_ENABLED)) { - mutex_unlock(&(dma_ch[channel].dmalock)); + if (atomic_cmpxchg(&dma_ch[channel].chan_status, 0, 1)) { pr_debug("DMA CHANNEL IN USE \n"); return -EBUSY; - } else { - dma_ch[channel].chan_status = DMA_CHANNEL_REQUESTED; - pr_debug("DMA CHANNEL IS ALLOCATED \n"); } - mutex_unlock(&(dma_ch[channel].dmalock)); - #ifdef CONFIG_BF54x if (channel >= CH_UART2_RX && channel <= CH_UART3_TX) { unsigned int per_map; @@ -149,7 +139,7 @@ EXPORT_SYMBOL(request_dma); int set_dma_callback(unsigned int channel, irq_handler_t callback, void *data) { BUG_ON(channel >= MAX_DMA_CHANNELS || - dma_ch[channel].chan_status == DMA_CHANNEL_FREE); + !atomic_read(&dma_ch[channel].chan_status)); if (callback != NULL) { int ret; @@ -184,7 +174,7 @@ void free_dma(unsigned int channel) { pr_debug("freedma() : BEGIN \n"); BUG_ON(channel >= MAX_DMA_CHANNELS || - dma_ch[channel].chan_status == DMA_CHANNEL_FREE); + !atomic_read(&dma_ch[channel].chan_status)); /* Halt the DMA */ disable_dma(channel); @@ -194,9 +184,7 @@ void free_dma(unsigned int channel) free_irq(dma_ch[channel].irq, dma_ch[channel].data); /* Clear the DMA Variable in the Channel */ - mutex_lock(&(dma_ch[channel].dmalock)); - dma_ch[channel].chan_status = DMA_CHANNEL_FREE; - mutex_unlock(&(dma_ch[channel].dmalock)); + atomic_set(&dma_ch[channel].chan_status, 0); pr_debug("freedma() : END \n"); } @@ -210,13 +198,14 @@ int blackfin_dma_suspend(void) { int i; - for (i = 0; i < MAX_DMA_SUSPEND_CHANNELS; ++i) { - if (dma_ch[i].chan_status == DMA_CHANNEL_ENABLED) { + for (i = 0; i < MAX_DMA_CHANNELS; ++i) { + if (dma_ch[i].regs->cfg & DMAEN) { printk(KERN_ERR "DMA Channel %d failed to suspend\n", i); return -EBUSY; } - dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map; + if (i < MAX_DMA_SUSPEND_CHANNELS) + dma_ch[i].saved_peripheral_map = dma_ch[i].regs->peripheral_map; } return 0; |