diff options
Diffstat (limited to 'arch/arm/mach-imx/dma-v1.c')
| -rw-r--r-- | arch/arm/mach-imx/dma-v1.c | 862 |
1 files changed, 862 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/dma-v1.c b/arch/arm/mach-imx/dma-v1.c new file mode 100644 index 0000000..3e8c47c --- /dev/null +++ b/arch/arm/mach-imx/dma-v1.c @@ -0,0 +1,862 @@ +/* + * linux/arch/arm/plat-mxc/dma-v1.c + * + * i.MX DMA registration and IRQ dispatching + * + * Copyright 2006 Pavel Pisa <pisa@cmp.felk.cvut.cz> + * Copyright 2008 Juergen Beisert, <kernel@pengutronix.de> + * Copyright 2008 Sascha Hauer, <s.hauer@pengutronix.de> + * + * 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 the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/clk.h> +#include <linux/scatterlist.h> +#include <linux/io.h> + +#include <asm/system.h> +#include <asm/irq.h> +#include <mach/hardware.h> +#include <mach/dma-v1.h> + +#define DMA_DCR 0x00 /* Control Register */ +#define DMA_DISR 0x04 /* Interrupt status Register */ +#define DMA_DIMR 0x08 /* Interrupt mask Register */ +#define DMA_DBTOSR 0x0c /* Burst timeout status Register */ +#define DMA_DRTOSR 0x10 /* Request timeout Register */ +#define DMA_DSESR 0x14 /* Transfer Error Status Register */ +#define DMA_DBOSR 0x18 /* Buffer overflow status Register */ +#define DMA_DBTOCR 0x1c /* Burst timeout control Register */ +#define DMA_WSRA 0x40 /* W-Size Register A */ +#define DMA_XSRA 0x44 /* X-Size Register A */ +#define DMA_YSRA 0x48 /* Y-Size Register A */ +#define DMA_WSRB 0x4c /* W-Size Register B */ +#define DMA_XSRB 0x50 /* X-Size Register B */ +#define DMA_YSRB 0x54 /* Y-Size Register B */ +#define DMA_SAR(x) (0x80 + ((x) << 6)) /* Source Address Registers */ +#define DMA_DAR(x) (0x84 + ((x) << 6)) /* Destination Address Registers */ +#define DMA_CNTR(x) (0x88 + ((x) << 6)) /* Count Registers */ +#define DMA_CCR(x) (0x8c + ((x) << 6)) /* Control Registers */ +#define DMA_RSSR(x) (0x90 + ((x) << 6)) /* Request source select Registers */ +#define DMA_BLR(x) (0x94 + ((x) << 6)) /* Burst length Registers */ +#define DMA_RTOR(x) (0x98 + ((x) << 6)) /* Request timeout Registers */ +#define DMA_BUCR(x) (0x98 + ((x) << 6)) /* Bus Utilization Registers */ +#define DMA_CCNR(x) (0x9C + ((x) << 6)) /* Channel counter Registers */ + +#define DCR_DRST (1<<1) +#define DCR_DEN (1<<0) +#define DBTOCR_EN (1<<15) +#define DBTOCR_CNT(x) ((x) & 0x7fff) +#define CNTR_CNT(x) ((x) & 0xffffff) +#define CCR_ACRPT (1<<14) +#define CCR_DMOD_LINEAR (0x0 << 12) +#define CCR_DMOD_2D (0x1 << 12) +#define CCR_DMOD_FIFO (0x2 << 12) +#define CCR_DMOD_EOBFIFO (0x3 << 12) +#define CCR_SMOD_LINEAR (0x0 << 10) +#define CCR_SMOD_2D (0x1 << 10) +#define CCR_SMOD_FIFO (0x2 << 10) +#define CCR_SMOD_EOBFIFO (0x3 << 10) +#define CCR_MDIR_DEC (1<<9) +#define CCR_MSEL_B (1<<8) +#define CCR_DSIZ_32 (0x0 << 6) +#define CCR_DSIZ_8 (0x1 << 6) +#define CCR_DSIZ_16 (0x2 << 6) +#define CCR_SSIZ_32 (0x0 << 4) +#define CCR_SSIZ_8 (0x1 << 4) +#define CCR_SSIZ_16 (0x2 << 4) +#define CCR_REN (1<<3) +#define CCR_RPT (1<<2) +#define CCR_FRC (1<<1) +#define CCR_CEN (1<<0) +#define RTOR_EN (1<<15) +#define RTOR_CLK (1<<14) +#define RTOR_PSC (1<<13) + +/* + * struct imx_dma_channel - i.MX specific DMA extension + * @name: name specified by DMA client + * @irq_handler: client callback for end of transfer + * @err_handler: client callback for error condition + * @data: clients context data for callbacks + * @dma_mode: direction of the transfer %DMA_MODE_READ or %DMA_MODE_WRITE + * @sg: pointer to the actual read/written chunk for scatter-gather emulation + * @resbytes: total residual number of bytes to transfer + * (it can be lower or same as sum of SG mapped chunk sizes) + * @sgcount: number of chunks to be read/written + * + * Structure is used for IMX DMA processing. It would be probably good + * @struct dma_struct in the future for external interfacing and use + * @struct imx_dma_channel only as extension to it. + */ + +struct imx_dma_channel { + const char *name; + void (*irq_handler) (int, void *); + void (*err_handler) (int, void *, int errcode); + void (*prog_handler) (int, void *, struct scatterlist *); + void *data; + unsigned int dma_mode; + struct scatterlist *sg; + unsigned int resbytes; + int dma_num; + + int in_use; + + u32 ccr_from_device; + u32 ccr_to_device; + + struct timer_list watchdog; + + int hw_chaining; +}; + +static void __iomem *imx_dmav1_baseaddr; + +static void imx_dmav1_writel(unsigned val, unsigned offset) +{ + __raw_writel(val, imx_dmav1_baseaddr + offset); +} + +static unsigned imx_dmav1_readl(unsigned offset) +{ + return __raw_readl(imx_dmav1_baseaddr + offset); +} + +static struct imx_dma_channel imx_dma_channels[IMX_DMA_CHANNELS]; + +static struct clk *dma_clk; + +static int imx_dma_hw_chain(struct imx_dma_channel *imxdma) +{ + if (cpu_is_mx27()) + return imxdma->hw_chaining; + else + return 0; +} + +/* + * imx_dma_sg_next - prepare next chunk for scatter-gather DMA emulation + */ +static inline int imx_dma_sg_next(int channel, struct scatterlist *sg) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long now; + + if (!imxdma->name) { + printk(KERN_CRIT "%s: called for not allocated channel %d\n", + __func__, channel); + return 0; + } + + now = min(imxdma->resbytes, sg->length); + if (imxdma->resbytes != IMX_DMA_LENGTH_LOOP) + imxdma->resbytes -= now; + + if ((imxdma->dma_mode & DMA_MODE_MASK) == DMA_MODE_READ) + imx_dmav1_writel(sg->dma_address, DMA_DAR(channel)); + else + imx_dmav1_writel(sg->dma_address, DMA_SAR(channel)); + + imx_dmav1_writel(now, DMA_CNTR(channel)); + + pr_debug("imxdma%d: next sg chunk dst 0x%08x, src 0x%08x, " + "size 0x%08x\n", channel, + imx_dmav1_readl(DMA_DAR(channel)), + imx_dmav1_readl(DMA_SAR(channel)), + imx_dmav1_readl(DMA_CNTR(channel))); + + return now; +} + +/** + * imx_dma_setup_single - setup i.MX DMA channel for linear memory to/from + * device transfer + * + * @channel: i.MX DMA channel number + * @dma_address: the DMA/physical memory address of the linear data block + * to transfer + * @dma_length: length of the data block in bytes + * @dev_addr: physical device port address + * @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory + * or %DMA_MODE_WRITE from memory to the device + * + * Return value: if incorrect parameters are provided -%EINVAL. + * Zero indicates success. + */ +int +imx_dma_setup_single(int channel, dma_addr_t dma_address, + unsigned int dma_length, unsigned int dev_addr, + unsigned int dmamode) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + + imxdma->sg = NULL; + imxdma->dma_mode = dmamode; + + if (!dma_address) { + printk(KERN_ERR "imxdma%d: imx_dma_setup_single null address\n", + channel); + return -EINVAL; + } + + if (!dma_length) { + printk(KERN_ERR "imxdma%d: imx_dma_setup_single zero length\n", + channel); + return -EINVAL; + } + + if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) { + pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d " + "dev_addr=0x%08x for read\n", + channel, __func__, (unsigned int)dma_address, + dma_length, dev_addr); + + imx_dmav1_writel(dev_addr, DMA_SAR(channel)); + imx_dmav1_writel(dma_address, DMA_DAR(channel)); + imx_dmav1_writel(imxdma->ccr_from_device, DMA_CCR(channel)); + } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) { + pr_debug("imxdma%d: %s dma_addressg=0x%08x dma_length=%d " + "dev_addr=0x%08x for write\n", + channel, __func__, (unsigned int)dma_address, + dma_length, dev_addr); + + imx_dmav1_writel(dma_address, DMA_SAR(channel)); + imx_dmav1_writel(dev_addr, DMA_DAR(channel)); + imx_dmav1_writel(imxdma->ccr_to_device, + DMA_CCR(channel)); + } else { + printk(KERN_ERR "imxdma%d: imx_dma_setup_single bad dmamode\n", + channel); + return -EINVAL; + } + + imx_dmav1_writel(dma_length, DMA_CNTR(channel)); + + return 0; +} +EXPORT_SYMBOL(imx_dma_setup_single); + +/** + * imx_dma_setup_sg - setup i.MX DMA channel SG list to/from device transfer + * @channel: i.MX DMA channel number + * @sg: pointer to the scatter-gather list/vector + * @sgcount: scatter-gather list hungs count + * @dma_length: total length of the transfer request in bytes + * @dev_addr: physical device port address + * @dmamode: DMA transfer mode, %DMA_MODE_READ from the device to the memory + * or %DMA_MODE_WRITE from memory to the device + * + * The function sets up DMA channel state and registers to be ready for + * transfer specified by provided parameters. The scatter-gather emulation + * is set up according to the parameters. + * + * The full preparation of the transfer requires setup of more register + * by the caller before imx_dma_enable() can be called. + * + * %BLR(channel) holds transfer burst length in bytes, 0 means 64 bytes + * + * %RSSR(channel) has to be set to the DMA request line source %DMA_REQ_xxx + * + * %CCR(channel) has to specify transfer parameters, the next settings is + * typical for linear or simple scatter-gather transfers if %DMA_MODE_READ is + * specified + * + * %CCR_DMOD_LINEAR | %CCR_DSIZ_32 | %CCR_SMOD_FIFO | %CCR_SSIZ_x + * + * The typical setup for %DMA_MODE_WRITE is specified by next options + * combination + * + * %CCR_SMOD_LINEAR | %CCR_SSIZ_32 | %CCR_DMOD_FIFO | %CCR_DSIZ_x + * + * Be careful here and do not mistakenly mix source and target device + * port sizes constants, they are really different: + * %CCR_SSIZ_8, %CCR_SSIZ_16, %CCR_SSIZ_32, + * %CCR_DSIZ_8, %CCR_DSIZ_16, %CCR_DSIZ_32 + * + * Return value: if incorrect parameters are provided -%EINVAL. + * Zero indicates success. + */ +int +imx_dma_setup_sg(int channel, + struct scatterlist *sg, unsigned int sgcount, + unsigned int dma_length, unsigned int dev_addr, + unsigned int dmamode) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + + if (imxdma->in_use) + return -EBUSY; + + imxdma->sg = sg; + imxdma->dma_mode = dmamode; + imxdma->resbytes = dma_length; + + if (!sg || !sgcount) { + printk(KERN_ERR "imxdma%d: imx_dma_setup_sg empty sg list\n", + channel); + return -EINVAL; + } + + if (!sg->length) { + printk(KERN_ERR "imxdma%d: imx_dma_setup_sg zero length\n", + channel); + return -EINVAL; + } + + if ((dmamode & DMA_MODE_MASK) == DMA_MODE_READ) { + pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d " + "dev_addr=0x%08x for read\n", + channel, __func__, sg, sgcount, dma_length, dev_addr); + + imx_dmav1_writel(dev_addr, DMA_SAR(channel)); + imx_dmav1_writel(imxdma->ccr_from_device, DMA_CCR(channel)); + } else if ((dmamode & DMA_MODE_MASK) == DMA_MODE_WRITE) { + pr_debug("imxdma%d: %s sg=%p sgcount=%d total length=%d " + "dev_addr=0x%08x for write\n", + channel, __func__, sg, sgcount, dma_length, dev_addr); + + imx_dmav1_writel(dev_addr, DMA_DAR(channel)); + imx_dmav1_writel(imxdma->ccr_to_device, DMA_CCR(channel)); + } else { + printk(KERN_ERR "imxdma%d: imx_dma_setup_sg bad dmamode\n", + channel); + return -EINVAL; + } + + imx_dma_sg_next(channel, sg); + + return 0; +} +EXPORT_SYMBOL(imx_dma_setup_sg); + +int +imx_dma_config_channel(int channel, unsigned int config_port, + unsigned int config_mem, unsigned int dmareq, int hw_chaining) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + u32 dreq = 0; + + imxdma->hw_chaining = 0; + + if (hw_chaining) { + imxdma->hw_chaining = 1; + if (!imx_dma_hw_chain(imxdma)) + return -EINVAL; + } + + if (dmareq) + dreq = CCR_REN; + + imxdma->ccr_from_device = config_port | (config_mem << 2) | dreq; + imxdma->ccr_to_device = config_mem | (config_port << 2) | dreq; + + imx_dmav1_writel(dmareq, DMA_RSSR(channel)); + + return 0; +} +EXPORT_SYMBOL(imx_dma_config_channel); + +void imx_dma_config_burstlen(int channel, unsigned int burstlen) +{ + imx_dmav1_writel(burstlen, DMA_BLR(channel)); +} +EXPORT_SYMBOL(imx_dma_config_burstlen); + +/** + * imx_dma_setup_handlers - setup i.MX DMA channel end and error notification + * handlers + * @channel: i.MX DMA channel number + * @irq_handler: the pointer to the function called if the transfer + * ends successfully + * @err_handler: the pointer to the function called if the premature + * end caused by error occurs + * @data: user specified value to be passed to the handlers + */ +int +imx_dma_setup_handlers(int channel, + void (*irq_handler) (int, void *), + void (*err_handler) (int, void *, int), + void *data) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long flags; + + if (!imxdma->name) { + printk(KERN_CRIT "%s: called for not allocated channel %d\n", + __func__, channel); + return -ENODEV; + } + + local_irq_save(flags); + imx_dmav1_writel(1 << channel, DMA_DISR); + imxdma->irq_handler = irq_handler; + imxdma->err_handler = err_handler; + imxdma->data = data; + local_irq_restore(flags); + return 0; +} +EXPORT_SYMBOL(imx_dma_setup_handlers); + +/** + * imx_dma_setup_progression_handler - setup i.MX DMA channel progression + * handlers + * @channel: i.MX DMA channel number + * @prog_handler: the pointer to the function called if the transfer progresses + */ +int +imx_dma_setup_progression_handler(int channel, + void (*prog_handler) (int, void*, struct scatterlist*)) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long flags; + + if (!imxdma->name) { + printk(KERN_CRIT "%s: called for not allocated channel %d\n", + __func__, channel); + return -ENODEV; + } + + local_irq_save(flags); + imxdma->prog_handler = prog_handler; + local_irq_restore(flags); + return 0; +} +EXPORT_SYMBOL(imx_dma_setup_progression_handler); + +/** + * imx_dma_enable - function to start i.MX DMA channel operation + * @channel: i.MX DMA channel number + * + * The channel has to be allocated by driver through imx_dma_request() + * or imx_dma_request_by_prio() function. + * The transfer parameters has to be set to the channel registers through + * call of the imx_dma_setup_single() or imx_dma_setup_sg() function + * and registers %BLR(channel), %RSSR(channel) and %CCR(channel) has to + * be set prior this function call by the channel user. + */ +void imx_dma_enable(int channel) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long flags; + + pr_debug("imxdma%d: imx_dma_enable\n", channel); + + if (!imxdma->name) { + printk(KERN_CRIT "%s: called for not allocated channel %d\n", + __func__, channel); + return; + } + + if (imxdma->in_use) + return; + + local_irq_save(flags); + + imx_dmav1_writel(1 << channel, DMA_DISR); + imx_dmav1_writel(imx_dmav1_readl(DMA_DIMR) & ~(1 << channel), DMA_DIMR); + imx_dmav1_writel(imx_dmav1_readl(DMA_CCR(channel)) | CCR_CEN | + CCR_ACRPT, DMA_CCR(channel)); + +#ifdef CONFIG_ARCH_MX2 + if ((cpu_is_mx21() || cpu_is_mx27()) && + imxdma->sg && imx_dma_hw_chain(imxdma)) { + imxdma->sg = sg_next(imxdma->sg); + if (imxdma->sg) { + u32 tmp; + imx_dma_sg_next(channel, imxdma->sg); + tmp = imx_dmav1_readl(DMA_CCR(channel)); + imx_dmav1_writel(tmp | CCR_RPT | CCR_ACRPT, + DMA_CCR(channel)); + } + } +#endif + imxdma->in_use = 1; + + local_irq_restore(flags); +} +EXPORT_SYMBOL(imx_dma_enable); + +/** + * imx_dma_disable - stop, finish i.MX DMA channel operatin + * @channel: i.MX DMA channel number + */ +void imx_dma_disable(int channel) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long flags; + + pr_debug("imxdma%d: imx_dma_disable\n", channel); + + if (imx_dma_hw_chain(imxdma)) + del_timer(&imxdma->watchdog); + + local_irq_save(flags); + imx_dmav1_writel(imx_dmav1_readl(DMA_DIMR) | (1 << channel), DMA_DIMR); + imx_dmav1_writel(imx_dmav1_readl(DMA_CCR(channel)) & ~CCR_CEN, + DMA_CCR(channel)); + imx_dmav1_writel(1 << channel, DMA_DISR); + imxdma->in_use = 0; + local_irq_restore(flags); +} +EXPORT_SYMBOL(imx_dma_disable); + +#ifdef CONFIG_ARCH_MX2 +static void imx_dma_watchdog(unsigned long chno) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[chno]; + + imx_dmav1_writel(0, DMA_CCR(chno)); + imxdma->in_use = 0; + imxdma->sg = NULL; + + if (imxdma->err_handler) + imxdma->err_handler(chno, imxdma->data, IMX_DMA_ERR_TIMEOUT); +} +#endif + +static irqreturn_t dma_err_handler(int irq, void *dev_id) +{ + int i, disr; + struct imx_dma_channel *imxdma; + unsigned int err_mask; + int errcode; + + disr = imx_dmav1_readl(DMA_DISR); + + err_mask = imx_dmav1_readl(DMA_DBTOSR) | + imx_dmav1_readl(DMA_DRTOSR) | + imx_dmav1_readl(DMA_DSESR) | + imx_dmav1_readl(DMA_DBOSR); + + if (!err_mask) + return IRQ_HANDLED; + + imx_dmav1_writel(disr & err_mask, DMA_DISR); + + for (i = 0; i < IMX_DMA_CHANNELS; i++) { + if (!(err_mask & (1 << i))) + continue; + imxdma = &imx_dma_channels[i]; + errcode = 0; + + if (imx_dmav1_readl(DMA_DBTOSR) & (1 << i)) { + imx_dmav1_writel(1 << i, DMA_DBTOSR); + errcode |= IMX_DMA_ERR_BURST; + } + if (imx_dmav1_readl(DMA_DRTOSR) & (1 << i)) { + imx_dmav1_writel(1 << i, DMA_DRTOSR); + errcode |= IMX_DMA_ERR_REQUEST; + } + if (imx_dmav1_readl(DMA_DSESR) & (1 << i)) { + imx_dmav1_writel(1 << i, DMA_DSESR); + errcode |= IMX_DMA_ERR_TRANSFER; + } + if (imx_dmav1_readl(DMA_DBOSR) & (1 << i)) { + imx_dmav1_writel(1 << i, DMA_DBOSR); + errcode |= IMX_DMA_ERR_BUFFER; + } + if (imxdma->name && imxdma->err_handler) { + imxdma->err_handler(i, imxdma->data, errcode); + continue; + } + + imx_dma_channels[i].sg = NULL; + + printk(KERN_WARNING + "DMA timeout on channel %d (%s) -%s%s%s%s\n", + i, imxdma->name, + errcode & IMX_DMA_ERR_BURST ? " burst" : "", + errcode & IMX_DMA_ERR_REQUEST ? " request" : "", + errcode & IMX_DMA_ERR_TRANSFER ? " transfer" : "", + errcode & IMX_DMA_ERR_BUFFER ? " buffer" : ""); + } + return IRQ_HANDLED; +} + +static void dma_irq_handle_channel(int chno) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[chno]; + + if (!imxdma->name) { + /* + * IRQ for an unregistered DMA channel: + * let's clear the interrupts and disable it. + */ + printk(KERN_WARNING + "spurious IRQ for DMA channel %d\n", chno); + return; + } + + if (imxdma->sg) { + u32 tmp; + struct scatterlist *current_sg = imxdma->sg; + imxdma->sg = sg_next(imxdma->sg); + + if (imxdma->sg) { + imx_dma_sg_next(chno, imxdma->sg); + + tmp = imx_dmav1_readl(DMA_CCR(chno)); + + if (imx_dma_hw_chain(imxdma)) { + /* FIXME: The timeout should probably be + * configurable + */ + mod_timer(&imxdma->watchdog, + jiffies + msecs_to_jiffies(500)); + + tmp |= CCR_CEN | CCR_RPT | CCR_ACRPT; + imx_dmav1_writel(tmp, DMA_CCR(chno)); + } else { + imx_dmav1_writel(tmp & ~CCR_CEN, DMA_CCR(chno)); + tmp |= CCR_CEN; + } + + imx_dmav1_writel(tmp, DMA_CCR(chno)); + + if (imxdma->prog_handler) + imxdma->prog_handler(chno, imxdma->data, + current_sg); + + return; + } + + if (imx_dma_hw_chain(imxdma)) { + del_timer(&imxdma->watchdog); + return; + } + } + + imx_dmav1_writel(0, DMA_CCR(chno)); + imxdma->in_use = 0; + if (imxdma->irq_handler) + imxdma->irq_handler(chno, imxdma->data); +} + +static irqreturn_t dma_irq_handler(int irq, void *dev_id) +{ + int i, disr; + +#ifdef CONFIG_ARCH_MX2 + if (cpu_is_mx21() || cpu_is_mx27()) + dma_err_handler(irq, dev_id); +#endif + + disr = imx_dmav1_readl(DMA_DISR); + + pr_debug("imxdma: dma_irq_handler called, disr=0x%08x\n", + disr); + + imx_dmav1_writel(disr, DMA_DISR); + for (i = 0; i < IMX_DMA_CHANNELS; i++) { + if (disr & (1 << i)) + dma_irq_handle_channel(i); + } + + return IRQ_HANDLED; +} + +/** + * imx_dma_request - request/allocate specified channel number + * @channel: i.MX DMA channel number + * @name: the driver/caller own non-%NULL identification + */ +int imx_dma_request(int channel, const char *name) +{ + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + unsigned long flags; + int ret = 0; + + /* basic sanity checks */ + if (!name) + return -EINVAL; + + if (channel >= IMX_DMA_CHANNELS) { + printk(KERN_CRIT "%s: called for non-existed channel %d\n", + __func__, channel); + return -EINVAL; + } + + local_irq_save(flags); + if (imxdma->name) { + local_irq_restore(flags); + return -EBUSY; + } + memset(imxdma, 0, sizeof(imxdma)); + imxdma->name = name; + local_irq_restore(flags); /* request_irq() can block */ + +#ifdef CONFIG_ARCH_MX2 + if (cpu_is_mx21() || cpu_is_mx27()) { + ret = request_irq(MX2x_INT_DMACH0 + channel, + dma_irq_handler, 0, "DMA", NULL); + if (ret) { + imxdma->name = NULL; + pr_crit("Can't register IRQ %d for DMA channel %d\n", + MX2x_INT_DMACH0 + channel, channel); + return ret; + } + init_timer(&imxdma->watchdog); + imxdma->watchdog.function = &imx_dma_watchdog; + imxdma->watchdog.data = channel; + } +#endif + + return ret; +} +EXPORT_SYMBOL(imx_dma_request); + +/** + * imx_dma_free - release previously acquired channel + * @channel: i.MX DMA channel number + */ +void imx_dma_free(int channel) +{ + unsigned long flags; + struct imx_dma_channel *imxdma = &imx_dma_channels[channel]; + + if (!imxdma->name) { + printk(KERN_CRIT + "%s: trying to free free channel %d\n", + __func__, channel); + return; + } + + local_irq_save(flags); + /* Disable interrupts */ + imx_dma_disable(channel); + imxdma->name = NULL; + +#ifdef CONFIG_ARCH_MX2 + if (cpu_is_mx21() || cpu_is_mx27()) + free_irq(MX2x_INT_DMACH0 + channel, NULL); +#endif + + local_irq_restore(flags); +} +EXPORT_SYMBOL(imx_dma_free); + +/** + * imx_dma_request_by_prio - find and request some of free channels best + * suiting requested priority + * @channel: i.MX DMA channel number + * @name: the driver/caller own non-%NULL identification + * + * This function tries to find a free channel in the specified priority group + * if the priority cannot be achieved it tries to look for free channel + * in the higher and then even lower priority groups. + * + * Return value: If there is no free channel to allocate, -%ENODEV is returned. + * On successful allocation channel is returned. + */ +int imx_dma_request_by_prio(const char *name, enum imx_dma_prio prio) +{ + int i; + int best; + + switch (prio) { + case (DMA_PRIO_HIGH): + best = 8; + break; + case (DMA_PRIO_MEDIUM): + best = 4; + break; + case (DMA_PRIO_LOW): + default: + best = 0; + break; + } + + for (i = best; i < IMX_DMA_CHANNELS; i++) + if (!imx_dma_request(i, name)) + return i; + + for (i = best - 1; i >= 0; i--) + if (!imx_dma_request(i, name)) + return i; + + printk(KERN_ERR "%s: no free DMA channel found\n", __func__); + + return -ENODEV; +} +EXPORT_SYMBOL(imx_dma_request_by_prio); + +static int __init imx_dma_init(void) +{ + int ret = 0; + int i; + +#ifdef CONFIG_ARCH_MX1 + if (cpu_is_mx1()) + imx_dmav1_baseaddr = MX1_IO_ADDRESS(MX1_DMA_BASE_ADDR); + else +#endif +#ifdef CONFIG_MACH_MX21 + if (cpu_is_mx21()) + imx_dmav1_baseaddr = MX21_IO_ADDRESS(MX21_DMA_BASE_ADDR); + else +#endif +#ifdef CONFIG_MACH_MX27 + if (cpu_is_mx27()) + imx_dmav1_baseaddr = MX27_IO_ADDRESS(MX27_DMA_BASE_ADDR); + else +#endif + BUG(); + + dma_clk = clk_get(NULL, "dma"); + clk_enable(dma_clk); + + /* reset DMA module */ + imx_dmav1_writel(DCR_DRST, DMA_DCR); + +#ifdef CONFIG_ARCH_MX1 + if (cpu_is_mx1()) { + ret = request_irq(MX1_DMA_INT, dma_irq_handler, 0, "DMA", NULL); + if (ret) { + pr_crit("Wow! Can't register IRQ for DMA\n"); + return ret; + } + + ret = request_irq(MX1_DMA_ERR, dma_err_handler, 0, "DMA", NULL); + if (ret) { + pr_crit("Wow! Can't register ERRIRQ for DMA\n"); + free_irq(MX1_DMA_INT, NULL); + return ret; + } + } +#endif + /* enable DMA module */ + imx_dmav1_writel(DCR_DEN, DMA_DCR); + + /* clear all interrupts */ + imx_dmav1_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_DISR); + + /* disable interrupts */ + imx_dmav1_writel((1 << IMX_DMA_CHANNELS) - 1, DMA_DIMR); + + for (i = 0; i < IMX_DMA_CHANNELS; i++) { + imx_dma_channels[i].sg = NULL; + imx_dma_channels[i].dma_num = i; + } + + return ret; +} + +arch_initcall(imx_dma_init); |
