diff options
Diffstat (limited to 'arch/arm/mach-s3c64xx/dma.c')
-rw-r--r-- | arch/arm/mach-s3c64xx/dma.c | 750 |
1 files changed, 750 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c64xx/dma.c b/arch/arm/mach-s3c64xx/dma.c new file mode 100644 index 000000000000..0e0edf75e8ed --- /dev/null +++ b/arch/arm/mach-s3c64xx/dma.c @@ -0,0 +1,750 @@ +/* linux/arch/arm/plat-s3c64xx/dma.c + * + * Copyright 2009 Openmoko, Inc. + * Copyright 2009 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk> + * http://armlinux.simtec.co.uk/ + * + * S3C64XX DMA core + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/dmapool.h> +#include <linux/sysdev.h> +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <mach/dma.h> +#include <mach/map.h> +#include <mach/irqs.h> + +#include <plat/dma-plat.h> +#include <mach/regs-sys.h> + +#include <asm/hardware/pl080.h> + +/* dma channel state information */ + +struct s3c64xx_dmac { + struct sys_device sysdev; + struct clk *clk; + void __iomem *regs; + struct s3c2410_dma_chan *channels; + enum dma_ch chanbase; +}; + +/* pool to provide LLI buffers */ +static struct dma_pool *dma_pool; + +/* Debug configuration and code */ + +static unsigned char debug_show_buffs = 0; + +static void dbg_showchan(struct s3c2410_dma_chan *chan) +{ + pr_debug("DMA%d: %08x->%08x L %08x C %08x,%08x S %08x\n", + chan->number, + readl(chan->regs + PL080_CH_SRC_ADDR), + readl(chan->regs + PL080_CH_DST_ADDR), + readl(chan->regs + PL080_CH_LLI), + readl(chan->regs + PL080_CH_CONTROL), + readl(chan->regs + PL080S_CH_CONTROL2), + readl(chan->regs + PL080S_CH_CONFIG)); +} + +static void show_lli(struct pl080s_lli *lli) +{ + pr_debug("LLI[%p] %08x->%08x, NL %08x C %08x,%08x\n", + lli, lli->src_addr, lli->dst_addr, lli->next_lli, + lli->control0, lli->control1); +} + +static void dbg_showbuffs(struct s3c2410_dma_chan *chan) +{ + struct s3c64xx_dma_buff *ptr; + struct s3c64xx_dma_buff *end; + + pr_debug("DMA%d: buffs next %p, curr %p, end %p\n", + chan->number, chan->next, chan->curr, chan->end); + + ptr = chan->next; + end = chan->end; + + if (debug_show_buffs) { + for (; ptr != NULL; ptr = ptr->next) { + pr_debug("DMA%d: %08x ", + chan->number, ptr->lli_dma); + show_lli(ptr->lli); + } + } +} + +/* End of Debug */ + +static struct s3c2410_dma_chan *s3c64xx_dma_map_channel(unsigned int channel) +{ + struct s3c2410_dma_chan *chan; + unsigned int start, offs; + + start = 0; + + if (channel >= DMACH_PCM1_TX) + start = 8; + + for (offs = 0; offs < 8; offs++) { + chan = &s3c2410_chans[start + offs]; + if (!chan->in_use) + goto found; + } + + return NULL; + +found: + s3c_dma_chan_map[channel] = chan; + return chan; +} + +int s3c2410_dma_config(unsigned int channel, int xferunit) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + + if (chan == NULL) + return -EINVAL; + + switch (xferunit) { + case 1: + chan->hw_width = 0; + break; + case 2: + chan->hw_width = 1; + break; + case 4: + chan->hw_width = 2; + break; + default: + printk(KERN_ERR "%s: illegal width %d\n", __func__, xferunit); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL(s3c2410_dma_config); + +static void s3c64xx_dma_fill_lli(struct s3c2410_dma_chan *chan, + struct pl080s_lli *lli, + dma_addr_t data, int size) +{ + dma_addr_t src, dst; + u32 control0, control1; + + switch (chan->source) { + case S3C2410_DMASRC_HW: + src = chan->dev_addr; + dst = data; + control0 = PL080_CONTROL_SRC_AHB2; + control0 |= PL080_CONTROL_DST_INCR; + break; + + case S3C2410_DMASRC_MEM: + src = data; + dst = chan->dev_addr; + control0 = PL080_CONTROL_DST_AHB2; + control0 |= PL080_CONTROL_SRC_INCR; + break; + default: + BUG(); + } + + /* note, we do not currently setup any of the burst controls */ + + control1 = size >> chan->hw_width; /* size in no of xfers */ + control0 |= PL080_CONTROL_PROT_SYS; /* always in priv. mode */ + control0 |= PL080_CONTROL_TC_IRQ_EN; /* always fire IRQ */ + control0 |= (u32)chan->hw_width << PL080_CONTROL_DWIDTH_SHIFT; + control0 |= (u32)chan->hw_width << PL080_CONTROL_SWIDTH_SHIFT; + + lli->src_addr = src; + lli->dst_addr = dst; + lli->next_lli = 0; + lli->control0 = control0; + lli->control1 = control1; +} + +static void s3c64xx_lli_to_regs(struct s3c2410_dma_chan *chan, + struct pl080s_lli *lli) +{ + void __iomem *regs = chan->regs; + + pr_debug("%s: LLI %p => regs\n", __func__, lli); + show_lli(lli); + + writel(lli->src_addr, regs + PL080_CH_SRC_ADDR); + writel(lli->dst_addr, regs + PL080_CH_DST_ADDR); + writel(lli->next_lli, regs + PL080_CH_LLI); + writel(lli->control0, regs + PL080_CH_CONTROL); + writel(lli->control1, regs + PL080S_CH_CONTROL2); +} + +static int s3c64xx_dma_start(struct s3c2410_dma_chan *chan) +{ + struct s3c64xx_dmac *dmac = chan->dmac; + u32 config; + u32 bit = chan->bit; + + dbg_showchan(chan); + + pr_debug("%s: clearing interrupts\n", __func__); + + /* clear interrupts */ + writel(bit, dmac->regs + PL080_TC_CLEAR); + writel(bit, dmac->regs + PL080_ERR_CLEAR); + + pr_debug("%s: starting channel\n", __func__); + + config = readl(chan->regs + PL080S_CH_CONFIG); + config |= PL080_CONFIG_ENABLE; + + pr_debug("%s: writing config %08x\n", __func__, config); + writel(config, chan->regs + PL080S_CH_CONFIG); + + return 0; +} + +static int s3c64xx_dma_stop(struct s3c2410_dma_chan *chan) +{ + u32 config; + int timeout; + + pr_debug("%s: stopping channel\n", __func__); + + dbg_showchan(chan); + + config = readl(chan->regs + PL080S_CH_CONFIG); + config |= PL080_CONFIG_HALT; + writel(config, chan->regs + PL080S_CH_CONFIG); + + timeout = 1000; + do { + config = readl(chan->regs + PL080S_CH_CONFIG); + pr_debug("%s: %d - config %08x\n", __func__, timeout, config); + if (config & PL080_CONFIG_ACTIVE) + udelay(10); + else + break; + } while (--timeout > 0); + + if (config & PL080_CONFIG_ACTIVE) { + printk(KERN_ERR "%s: channel still active\n", __func__); + return -EFAULT; + } + + config = readl(chan->regs + PL080S_CH_CONFIG); + config &= ~PL080_CONFIG_ENABLE; + writel(config, chan->regs + PL080S_CH_CONFIG); + + return 0; +} + +static inline void s3c64xx_dma_bufffdone(struct s3c2410_dma_chan *chan, + struct s3c64xx_dma_buff *buf, + enum s3c2410_dma_buffresult result) +{ + if (chan->callback_fn != NULL) + (chan->callback_fn)(chan, buf->pw, 0, result); +} + +static void s3c64xx_dma_freebuff(struct s3c64xx_dma_buff *buff) +{ + dma_pool_free(dma_pool, buff->lli, buff->lli_dma); + kfree(buff); +} + +static int s3c64xx_dma_flush(struct s3c2410_dma_chan *chan) +{ + struct s3c64xx_dma_buff *buff, *next; + u32 config; + + dbg_showchan(chan); + + pr_debug("%s: flushing channel\n", __func__); + + config = readl(chan->regs + PL080S_CH_CONFIG); + config &= ~PL080_CONFIG_ENABLE; + writel(config, chan->regs + PL080S_CH_CONFIG); + + /* dump all the buffers associated with this channel */ + + for (buff = chan->curr; buff != NULL; buff = next) { + next = buff->next; + pr_debug("%s: buff %p (next %p)\n", __func__, buff, buff->next); + + s3c64xx_dma_bufffdone(chan, buff, S3C2410_RES_ABORT); + s3c64xx_dma_freebuff(buff); + } + + chan->curr = chan->next = chan->end = NULL; + + return 0; +} + +int s3c2410_dma_ctrl(unsigned int channel, enum s3c2410_chan_op op) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + + WARN_ON(!chan); + if (!chan) + return -EINVAL; + + switch (op) { + case S3C2410_DMAOP_START: + return s3c64xx_dma_start(chan); + + case S3C2410_DMAOP_STOP: + return s3c64xx_dma_stop(chan); + + case S3C2410_DMAOP_FLUSH: + return s3c64xx_dma_flush(chan); + + /* belive PAUSE/RESUME are no-ops */ + case S3C2410_DMAOP_PAUSE: + case S3C2410_DMAOP_RESUME: + case S3C2410_DMAOP_STARTED: + case S3C2410_DMAOP_TIMEOUT: + return 0; + } + + return -ENOENT; +} +EXPORT_SYMBOL(s3c2410_dma_ctrl); + +/* s3c2410_dma_enque + * + */ + +int s3c2410_dma_enqueue(unsigned int channel, void *id, + dma_addr_t data, int size) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + struct s3c64xx_dma_buff *next; + struct s3c64xx_dma_buff *buff; + struct pl080s_lli *lli; + unsigned long flags; + int ret; + + WARN_ON(!chan); + if (!chan) + return -EINVAL; + + buff = kzalloc(sizeof(struct s3c64xx_dma_buff), GFP_ATOMIC); + if (!buff) { + printk(KERN_ERR "%s: no memory for buffer\n", __func__); + return -ENOMEM; + } + + lli = dma_pool_alloc(dma_pool, GFP_ATOMIC, &buff->lli_dma); + if (!lli) { + printk(KERN_ERR "%s: no memory for lli\n", __func__); + ret = -ENOMEM; + goto err_buff; + } + + pr_debug("%s: buff %p, dp %08x lli (%p, %08x) %d\n", + __func__, buff, data, lli, (u32)buff->lli_dma, size); + + buff->lli = lli; + buff->pw = id; + + s3c64xx_dma_fill_lli(chan, lli, data, size); + + local_irq_save(flags); + + if ((next = chan->next) != NULL) { + struct s3c64xx_dma_buff *end = chan->end; + struct pl080s_lli *endlli = end->lli; + + pr_debug("enquing onto channel\n"); + + end->next = buff; + endlli->next_lli = buff->lli_dma; + + if (chan->flags & S3C2410_DMAF_CIRCULAR) { + struct s3c64xx_dma_buff *curr = chan->curr; + lli->next_lli = curr->lli_dma; + } + + if (next == chan->curr) { + writel(buff->lli_dma, chan->regs + PL080_CH_LLI); + chan->next = buff; + } + + show_lli(endlli); + chan->end = buff; + } else { + pr_debug("enquing onto empty channel\n"); + + chan->curr = buff; + chan->next = buff; + chan->end = buff; + + s3c64xx_lli_to_regs(chan, lli); + } + + local_irq_restore(flags); + + show_lli(lli); + + dbg_showchan(chan); + dbg_showbuffs(chan); + return 0; + +err_buff: + kfree(buff); + return ret; +} + +EXPORT_SYMBOL(s3c2410_dma_enqueue); + + +int s3c2410_dma_devconfig(int channel, + enum s3c2410_dmasrc source, + unsigned long devaddr) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + u32 peripheral; + u32 config = 0; + + pr_debug("%s: channel %d, source %d, dev %08lx, chan %p\n", + __func__, channel, source, devaddr, chan); + + WARN_ON(!chan); + if (!chan) + return -EINVAL; + + peripheral = (chan->peripheral & 0xf); + chan->source = source; + chan->dev_addr = devaddr; + + pr_debug("%s: peripheral %d\n", __func__, peripheral); + + switch (source) { + case S3C2410_DMASRC_HW: + config = 2 << PL080_CONFIG_FLOW_CONTROL_SHIFT; + config |= peripheral << PL080_CONFIG_SRC_SEL_SHIFT; + break; + case S3C2410_DMASRC_MEM: + config = 1 << PL080_CONFIG_FLOW_CONTROL_SHIFT; + config |= peripheral << PL080_CONFIG_DST_SEL_SHIFT; + break; + default: + printk(KERN_ERR "%s: bad source\n", __func__); + return -EINVAL; + } + + /* allow TC and ERR interrupts */ + config |= PL080_CONFIG_TC_IRQ_MASK; + config |= PL080_CONFIG_ERR_IRQ_MASK; + + pr_debug("%s: config %08x\n", __func__, config); + + writel(config, chan->regs + PL080S_CH_CONFIG); + + return 0; +} +EXPORT_SYMBOL(s3c2410_dma_devconfig); + + +int s3c2410_dma_getposition(unsigned int channel, + dma_addr_t *src, dma_addr_t *dst) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + + WARN_ON(!chan); + if (!chan) + return -EINVAL; + + if (src != NULL) + *src = readl(chan->regs + PL080_CH_SRC_ADDR); + + if (dst != NULL) + *dst = readl(chan->regs + PL080_CH_DST_ADDR); + + return 0; +} +EXPORT_SYMBOL(s3c2410_dma_getposition); + +/* s3c2410_request_dma + * + * get control of an dma channel +*/ + +int s3c2410_dma_request(unsigned int channel, + struct s3c2410_dma_client *client, + void *dev) +{ + struct s3c2410_dma_chan *chan; + unsigned long flags; + + pr_debug("dma%d: s3c2410_request_dma: client=%s, dev=%p\n", + channel, client->name, dev); + + local_irq_save(flags); + + chan = s3c64xx_dma_map_channel(channel); + if (chan == NULL) { + local_irq_restore(flags); + return -EBUSY; + } + + dbg_showchan(chan); + + chan->client = client; + chan->in_use = 1; + chan->peripheral = channel; + + local_irq_restore(flags); + + /* need to setup */ + + pr_debug("%s: channel initialised, %p\n", __func__, chan); + + return chan->number | DMACH_LOW_LEVEL; +} + +EXPORT_SYMBOL(s3c2410_dma_request); + +/* s3c2410_dma_free + * + * release the given channel back to the system, will stop and flush + * any outstanding transfers, and ensure the channel is ready for the + * next claimant. + * + * Note, although a warning is currently printed if the freeing client + * info is not the same as the registrant's client info, the free is still + * allowed to go through. +*/ + +int s3c2410_dma_free(unsigned int channel, struct s3c2410_dma_client *client) +{ + struct s3c2410_dma_chan *chan = s3c_dma_lookup_channel(channel); + unsigned long flags; + + if (chan == NULL) + return -EINVAL; + + local_irq_save(flags); + + if (chan->client != client) { + printk(KERN_WARNING "dma%d: possible free from different client (channel %p, passed %p)\n", + channel, chan->client, client); + } + + /* sort out stopping and freeing the channel */ + + + chan->client = NULL; + chan->in_use = 0; + + if (!(channel & DMACH_LOW_LEVEL)) + s3c_dma_chan_map[channel] = NULL; + + local_irq_restore(flags); + + return 0; +} + +EXPORT_SYMBOL(s3c2410_dma_free); + +static irqreturn_t s3c64xx_dma_irq(int irq, void *pw) +{ + struct s3c64xx_dmac *dmac = pw; + struct s3c2410_dma_chan *chan; + enum s3c2410_dma_buffresult res; + u32 tcstat, errstat; + u32 bit; + int offs; + + tcstat = readl(dmac->regs + PL080_TC_STATUS); + errstat = readl(dmac->regs + PL080_ERR_STATUS); + + for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) { + struct s3c64xx_dma_buff *buff; + + if (!(errstat & bit) && !(tcstat & bit)) + continue; + + chan = dmac->channels + offs; + res = S3C2410_RES_ERR; + + if (tcstat & bit) { + writel(bit, dmac->regs + PL080_TC_CLEAR); + res = S3C2410_RES_OK; + } + + if (errstat & bit) + writel(bit, dmac->regs + PL080_ERR_CLEAR); + + /* 'next' points to the buffer that is next to the + * currently active buffer. + * For CIRCULAR queues, 'next' will be same as 'curr' + * when 'end' is the active buffer. + */ + buff = chan->curr; + while (buff && buff != chan->next + && buff->next != chan->next) + buff = buff->next; + + if (!buff) + BUG(); + + if (buff == chan->next) + buff = chan->end; + + s3c64xx_dma_bufffdone(chan, buff, res); + + /* Free the node and update curr, if non-circular queue */ + if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) { + chan->curr = buff->next; + s3c64xx_dma_freebuff(buff); + } + + /* Update 'next' */ + buff = chan->next; + if (chan->next == chan->end) { + chan->next = chan->curr; + if (!(chan->flags & S3C2410_DMAF_CIRCULAR)) + chan->end = NULL; + } else { + chan->next = buff->next; + } + } + + return IRQ_HANDLED; +} + +static struct sysdev_class dma_sysclass = { + .name = "s3c64xx-dma", +}; + +static int s3c64xx_dma_init1(int chno, enum dma_ch chbase, + int irq, unsigned int base) +{ + struct s3c2410_dma_chan *chptr = &s3c2410_chans[chno]; + struct s3c64xx_dmac *dmac; + char clkname[16]; + void __iomem *regs; + void __iomem *regptr; + int err, ch; + + dmac = kzalloc(sizeof(struct s3c64xx_dmac), GFP_KERNEL); + if (!dmac) { + printk(KERN_ERR "%s: failed to alloc mem\n", __func__); + return -ENOMEM; + } + + dmac->sysdev.id = chno / 8; + dmac->sysdev.cls = &dma_sysclass; + + err = sysdev_register(&dmac->sysdev); + if (err) { + printk(KERN_ERR "%s: failed to register sysdevice\n", __func__); + goto err_alloc; + } + + regs = ioremap(base, 0x200); + if (!regs) { + printk(KERN_ERR "%s: failed to ioremap()\n", __func__); + err = -ENXIO; + goto err_dev; + } + + snprintf(clkname, sizeof(clkname), "dma%d", dmac->sysdev.id); + + dmac->clk = clk_get(NULL, clkname); + if (IS_ERR(dmac->clk)) { + printk(KERN_ERR "%s: failed to get clock %s\n", __func__, clkname); + err = PTR_ERR(dmac->clk); + goto err_map; + } + + clk_enable(dmac->clk); + + dmac->regs = regs; + dmac->chanbase = chbase; + dmac->channels = chptr; + + err = request_irq(irq, s3c64xx_dma_irq, 0, "DMA", dmac); + if (err < 0) { + printk(KERN_ERR "%s: failed to get irq\n", __func__); + goto err_clk; + } + + regptr = regs + PL080_Cx_BASE(0); + + for (ch = 0; ch < 8; ch++, chno++, chptr++) { + printk(KERN_INFO "%s: registering DMA %d (%p)\n", + __func__, chno, regptr); + + chptr->bit = 1 << ch; + chptr->number = chno; + chptr->dmac = dmac; + chptr->regs = regptr; + regptr += PL008_Cx_STRIDE; + } + + /* for the moment, permanently enable the controller */ + writel(PL080_CONFIG_ENABLE, regs + PL080_CONFIG); + + printk(KERN_INFO "PL080: IRQ %d, at %p\n", irq, regs); + + return 0; + +err_clk: + clk_disable(dmac->clk); + clk_put(dmac->clk); +err_map: + iounmap(regs); +err_dev: + sysdev_unregister(&dmac->sysdev); +err_alloc: + kfree(dmac); + return err; +} + +static int __init s3c64xx_dma_init(void) +{ + int ret; + + printk(KERN_INFO "%s: Registering DMA channels\n", __func__); + + dma_pool = dma_pool_create("DMA-LLI", NULL, sizeof(struct pl080s_lli), 16, 0); + if (!dma_pool) { + printk(KERN_ERR "%s: failed to create pool\n", __func__); + return -ENOMEM; + } + + ret = sysdev_class_register(&dma_sysclass); + if (ret) { + printk(KERN_ERR "%s: failed to create sysclass\n", __func__); + return -ENOMEM; + } + + /* Set all DMA configuration to be DMA, not SDMA */ + writel(0xffffff, S3C_SYSREG(0x110)); + + /* Register standard DMA controlers */ + s3c64xx_dma_init1(0, DMACH_UART0, IRQ_DMA0, 0x75000000); + s3c64xx_dma_init1(8, DMACH_PCM1_TX, IRQ_DMA1, 0x75100000); + + return 0; +} + +arch_initcall(s3c64xx_dma_init); |