Add COH 901 318 DMA block driver v5
This patch adds support for the ST-Ericsson COH 901 318 DMA block,
found in the U300 series platforms. It registers a DMA slave for
device I/O and also a memcpy slave for memcpy.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
new file mode 100644
index 0000000..4a99cd9
--- /dev/null
+++ b/drivers/dma/coh901318.c
@@ -0,0 +1,1325 @@
+/*
+ * driver/dma/coh901318.c
+ *
+ * Copyright (C) 2007-2009 ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ * DMA driver for COH 901 318
+ * Author: Per Friden <per.friden@stericsson.com>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h> /* printk() */
+#include <linux/fs.h> /* everything... */
+#include <linux/slab.h> /* kmalloc() */
+#include <linux/dmaengine.h>
+#include <linux/platform_device.h>
+#include <linux/device.h>
+#include <linux/irqreturn.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <mach/coh901318.h>
+
+#include "coh901318_lli.h"
+
+#define COHC_2_DEV(cohc) (&cohc->chan.dev->device)
+
+#ifdef VERBOSE_DEBUG
+#define COH_DBG(x) ({ if (1) x; 0; })
+#else
+#define COH_DBG(x) ({ if (0) x; 0; })
+#endif
+
+struct coh901318_desc {
+ struct dma_async_tx_descriptor desc;
+ struct list_head node;
+ struct scatterlist *sg;
+ unsigned int sg_len;
+ struct coh901318_lli *data;
+ enum dma_data_direction dir;
+ int pending_irqs;
+ unsigned long flags;
+};
+
+struct coh901318_base {
+ struct device *dev;
+ void __iomem *virtbase;
+ struct coh901318_pool pool;
+ struct powersave pm;
+ struct dma_device dma_slave;
+ struct dma_device dma_memcpy;
+ struct coh901318_chan *chans;
+ struct coh901318_platform *platform;
+};
+
+struct coh901318_chan {
+ spinlock_t lock;
+ int allocated;
+ int completed;
+ int id;
+ int stopped;
+
+ struct work_struct free_work;
+ struct dma_chan chan;
+
+ struct tasklet_struct tasklet;
+
+ struct list_head active;
+ struct list_head queue;
+ struct list_head free;
+
+ unsigned long nbr_active_done;
+ unsigned long busy;
+ int pending_irqs;
+
+ struct coh901318_base *base;
+};
+
+static void coh901318_list_print(struct coh901318_chan *cohc,
+ struct coh901318_lli *lli)
+{
+ struct coh901318_lli *l;
+ dma_addr_t addr = virt_to_phys(lli);
+ int i = 0;
+
+ while (addr) {
+ l = phys_to_virt(addr);
+ dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
+ ", dst 0x%x, link 0x%x link_virt 0x%p\n",
+ i, l, l->control, l->src_addr, l->dst_addr,
+ l->link_addr, phys_to_virt(l->link_addr));
+ i++;
+ addr = l->link_addr;
+ }
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#define COH901318_DEBUGFS_ASSIGN(x, y) (x = y)
+
+static struct coh901318_base *debugfs_dma_base;
+static struct dentry *dma_dentry;
+
+static int coh901318_debugfs_open(struct inode *inode, struct file *file)
+{
+
+ file->private_data = inode->i_private;
+ return 0;
+}
+
+static int coh901318_debugfs_read(struct file *file, char __user *buf,
+ size_t count, loff_t *f_pos)
+{
+ u64 started_channels = debugfs_dma_base->pm.started_channels;
+ int pool_count = debugfs_dma_base->pool.debugfs_pool_counter;
+ int i;
+ int ret = 0;
+ char *dev_buf;
+ char *tmp;
+ int dev_size;
+
+ dev_buf = kmalloc(4*1024, GFP_KERNEL);
+ if (dev_buf == NULL)
+ goto err_kmalloc;
+ tmp = dev_buf;
+
+ tmp += sprintf(tmp, "DMA -- enable dma channels\n");
+
+ for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
+ if (started_channels & (1 << i))
+ tmp += sprintf(tmp, "channel %d\n", i);
+
+ tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);
+ dev_size = tmp - dev_buf;
+
+ /* No more to read if offset != 0 */
+ if (*f_pos > dev_size)
+ goto out;
+
+ if (count > dev_size - *f_pos)
+ count = dev_size - *f_pos;
+
+ if (copy_to_user(buf, dev_buf + *f_pos, count))
+ ret = -EINVAL;
+ ret = count;
+ *f_pos += count;
+
+ out:
+ kfree(dev_buf);
+ return ret;
+
+ err_kmalloc:
+ return 0;
+}
+
+static const struct file_operations coh901318_debugfs_status_operations = {
+ .owner = THIS_MODULE,
+ .open = coh901318_debugfs_open,
+ .read = coh901318_debugfs_read,
+};
+
+
+static int __init init_coh901318_debugfs(void)
+{
+
+ dma_dentry = debugfs_create_dir("dma", NULL);
+
+ (void) debugfs_create_file("status",
+ S_IFREG | S_IRUGO,
+ dma_dentry, NULL,
+ &coh901318_debugfs_status_operations);
+ return 0;
+}
+
+static void __exit exit_coh901318_debugfs(void)
+{
+ debugfs_remove_recursive(dma_dentry);
+}
+
+module_init(init_coh901318_debugfs);
+module_exit(exit_coh901318_debugfs);
+#else
+
+#define COH901318_DEBUGFS_ASSIGN(x, y)
+
+#endif /* CONFIG_DEBUG_FS */
+
+static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct coh901318_chan, chan);
+}
+
+static inline dma_addr_t
+cohc_dev_addr(struct coh901318_chan *cohc)
+{
+ return cohc->base->platform->chan_conf[cohc->id].dev_addr;
+}
+
+static inline const struct coh901318_params *
+cohc_chan_param(struct coh901318_chan *cohc)
+{
+ return &cohc->base->platform->chan_conf[cohc->id].param;
+}
+
+static inline const struct coh_dma_channel *
+cohc_chan_conf(struct coh901318_chan *cohc)
+{
+ return &cohc->base->platform->chan_conf[cohc->id];
+}
+
+static void enable_powersave(struct coh901318_chan *cohc)
+{
+ unsigned long flags;
+ struct powersave *pm = &cohc->base->pm;
+
+ spin_lock_irqsave(&pm->lock, flags);
+
+ pm->started_channels &= ~(1ULL << cohc->id);
+
+ if (!pm->started_channels) {
+ /* DMA no longer intends to access memory */
+ cohc->base->platform->access_memory_state(cohc->base->dev,
+ false);
+ }
+
+ spin_unlock_irqrestore(&pm->lock, flags);
+}
+static void disable_powersave(struct coh901318_chan *cohc)
+{
+ unsigned long flags;
+ struct powersave *pm = &cohc->base->pm;
+
+ spin_lock_irqsave(&pm->lock, flags);
+
+ if (!pm->started_channels) {
+ /* DMA intends to access memory */
+ cohc->base->platform->access_memory_state(cohc->base->dev,
+ true);
+ }
+
+ pm->started_channels |= (1ULL << cohc->id);
+
+ spin_unlock_irqrestore(&pm->lock, flags);
+}
+
+static inline int coh901318_set_ctrl(struct coh901318_chan *cohc, u32 control)
+{
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ writel(control,
+ virtbase + COH901318_CX_CTRL +
+ COH901318_CX_CTRL_SPACING * channel);
+ return 0;
+}
+
+static inline int coh901318_set_conf(struct coh901318_chan *cohc, u32 conf)
+{
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ writel(conf,
+ virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING*channel);
+ return 0;
+}
+
+
+static int coh901318_start(struct coh901318_chan *cohc)
+{
+ u32 val;
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ disable_powersave(cohc);
+
+ val = readl(virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+
+ /* Enable channel */
+ val |= COH901318_CX_CFG_CH_ENABLE;
+ writel(val, virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+
+ return 0;
+}
+
+static int coh901318_prep_linked_list(struct coh901318_chan *cohc,
+ struct coh901318_lli *data)
+{
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ BUG_ON(readl(virtbase + COH901318_CX_STAT +
+ COH901318_CX_STAT_SPACING*channel) &
+ COH901318_CX_STAT_ACTIVE);
+
+ writel(data->src_addr,
+ virtbase + COH901318_CX_SRC_ADDR +
+ COH901318_CX_SRC_ADDR_SPACING * channel);
+
+ writel(data->dst_addr, virtbase +
+ COH901318_CX_DST_ADDR +
+ COH901318_CX_DST_ADDR_SPACING * channel);
+
+ writel(data->link_addr, virtbase + COH901318_CX_LNK_ADDR +
+ COH901318_CX_LNK_ADDR_SPACING * channel);
+
+ writel(data->control, virtbase + COH901318_CX_CTRL +
+ COH901318_CX_CTRL_SPACING * channel);
+
+ return 0;
+}
+static dma_cookie_t
+coh901318_assign_cookie(struct coh901318_chan *cohc,
+ struct coh901318_desc *cohd)
+{
+ dma_cookie_t cookie = cohc->chan.cookie;
+
+ if (++cookie < 0)
+ cookie = 1;
+
+ cohc->chan.cookie = cookie;
+ cohd->desc.cookie = cookie;
+
+ return cookie;
+}
+
+static struct coh901318_desc *
+coh901318_desc_get(struct coh901318_chan *cohc)
+{
+ struct coh901318_desc *desc;
+
+ if (list_empty(&cohc->free)) {
+ /* alloc new desc because we're out of used ones
+ * TODO: alloc a pile of descs instead of just one,
+ * avoid many small allocations.
+ */
+ desc = kmalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
+ if (desc == NULL)
+ goto out;
+ INIT_LIST_HEAD(&desc->node);
+ } else {
+ /* Reuse an old desc. */
+ desc = list_first_entry(&cohc->free,
+ struct coh901318_desc,
+ node);
+ list_del(&desc->node);
+ }
+
+ out:
+ return desc;
+}
+
+static void
+coh901318_desc_free(struct coh901318_chan *cohc, struct coh901318_desc *cohd)
+{
+ list_add_tail(&cohd->node, &cohc->free);
+}
+
+/* call with irq lock held */
+static void
+coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
+{
+ list_add_tail(&desc->node, &cohc->active);
+
+ BUG_ON(cohc->pending_irqs != 0);
+
+ cohc->pending_irqs = desc->pending_irqs;
+}
+
+static struct coh901318_desc *
+coh901318_first_active_get(struct coh901318_chan *cohc)
+{
+ struct coh901318_desc *d;
+
+ if (list_empty(&cohc->active))
+ return NULL;
+
+ d = list_first_entry(&cohc->active,
+ struct coh901318_desc,
+ node);
+ return d;
+}
+
+static void
+coh901318_desc_remove(struct coh901318_desc *cohd)
+{
+ list_del(&cohd->node);
+}
+
+static void
+coh901318_desc_queue(struct coh901318_chan *cohc, struct coh901318_desc *desc)
+{
+ list_add_tail(&desc->node, &cohc->queue);
+}
+
+static struct coh901318_desc *
+coh901318_first_queued(struct coh901318_chan *cohc)
+{
+ struct coh901318_desc *d;
+
+ if (list_empty(&cohc->queue))
+ return NULL;
+
+ d = list_first_entry(&cohc->queue,
+ struct coh901318_desc,
+ node);
+ return d;
+}
+
+/*
+ * DMA start/stop controls
+ */
+u32 coh901318_get_bytes_left(struct dma_chan *chan)
+{
+ unsigned long flags;
+ u32 ret;
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* Read transfer count value */
+ ret = readl(cohc->base->virtbase +
+ COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
+ cohc->id) & COH901318_CX_CTRL_TC_VALUE_MASK;
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(coh901318_get_bytes_left);
+
+
+/* Stops a transfer without losing data. Enables power save.
+ Use this function in conjunction with coh901318_continue(..)
+*/
+void coh901318_stop(struct dma_chan *chan)
+{
+ u32 val;
+ unsigned long flags;
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* Disable channel in HW */
+ val = readl(virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+
+ /* Stopping infinit transfer */
+ if ((val & COH901318_CX_CTRL_TC_ENABLE) == 0 &&
+ (val & COH901318_CX_CFG_CH_ENABLE))
+ cohc->stopped = 1;
+
+
+ val &= ~COH901318_CX_CFG_CH_ENABLE;
+ /* Enable twice, HW bug work around */
+ writel(val, virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+ writel(val, virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+
+ /* Spin-wait for it to actually go inactive */
+ while (readl(virtbase + COH901318_CX_STAT+COH901318_CX_STAT_SPACING *
+ channel) & COH901318_CX_STAT_ACTIVE)
+ cpu_relax();
+
+ /* Check if we stopped an active job */
+ if ((readl(virtbase + COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *
+ channel) & COH901318_CX_CTRL_TC_VALUE_MASK) > 0)
+ cohc->stopped = 1;
+
+ enable_powersave(cohc);
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+}
+EXPORT_SYMBOL(coh901318_stop);
+
+/* Continues a transfer that has been stopped via 300_dma_stop(..).
+ Power save is handled.
+*/
+void coh901318_continue(struct dma_chan *chan)
+{
+ u32 val;
+ unsigned long flags;
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ int channel = cohc->id;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ disable_powersave(cohc);
+
+ if (cohc->stopped) {
+ /* Enable channel in HW */
+ val = readl(cohc->base->virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING * channel);
+
+ val |= COH901318_CX_CFG_CH_ENABLE;
+
+ writel(val, cohc->base->virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING*channel);
+
+ cohc->stopped = 0;
+ }
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+}
+EXPORT_SYMBOL(coh901318_continue);
+
+bool coh901318_filter_id(struct dma_chan *chan, void *chan_id)
+{
+ unsigned int ch_nr = (unsigned int) chan_id;
+
+ if (ch_nr == to_coh901318_chan(chan)->id)
+ return true;
+
+ return false;
+}
+EXPORT_SYMBOL(coh901318_filter_id);
+
+/*
+ * DMA channel allocation
+ */
+static int coh901318_config(struct coh901318_chan *cohc,
+ struct coh901318_params *param)
+{
+ unsigned long flags;
+ const struct coh901318_params *p;
+ int channel = cohc->id;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ if (param)
+ p = param;
+ else
+ p = &cohc->base->platform->chan_conf[channel].param;
+
+ /* Clear any pending BE or TC interrupt */
+ if (channel < 32) {
+ writel(1 << channel, virtbase + COH901318_BE_INT_CLEAR1);
+ writel(1 << channel, virtbase + COH901318_TC_INT_CLEAR1);
+ } else {
+ writel(1 << (channel - 32), virtbase +
+ COH901318_BE_INT_CLEAR2);
+ writel(1 << (channel - 32), virtbase +
+ COH901318_TC_INT_CLEAR2);
+ }
+
+ coh901318_set_conf(cohc, p->config);
+ coh901318_set_ctrl(cohc, p->ctrl_lli_last);
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+
+ return 0;
+}
+
+/* must lock when calling this function
+ * start queued jobs, if any
+ * TODO: start all queued jobs in one go
+ *
+ * Returns descriptor if queued job is started otherwise NULL.
+ * If the queue is empty NULL is returned.
+ */
+static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
+{
+ struct coh901318_desc *cohd_que;
+
+ /* start queued jobs, if any
+ * TODO: transmit all queued jobs in one go
+ */
+ cohd_que = coh901318_first_queued(cohc);
+
+ if (cohd_que != NULL) {
+ /* Remove from queue */
+ coh901318_desc_remove(cohd_que);
+ /* initiate DMA job */
+ cohc->busy = 1;
+
+ coh901318_desc_submit(cohc, cohd_que);
+
+ coh901318_prep_linked_list(cohc, cohd_que->data);
+
+ /* start dma job */
+ coh901318_start(cohc);
+
+ }
+
+ return cohd_que;
+}
+
+static void dma_tasklet(unsigned long data)
+{
+ struct coh901318_chan *cohc = (struct coh901318_chan *) data;
+ struct coh901318_desc *cohd_fin;
+ unsigned long flags;
+ dma_async_tx_callback callback;
+ void *callback_param;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* get first active entry from list */
+ cohd_fin = coh901318_first_active_get(cohc);
+
+ BUG_ON(cohd_fin->pending_irqs == 0);
+
+ if (cohd_fin == NULL)
+ goto err;
+
+ cohd_fin->pending_irqs--;
+ cohc->completed = cohd_fin->desc.cookie;
+
+ BUG_ON(cohc->nbr_active_done && cohd_fin == NULL);
+
+ if (cohc->nbr_active_done == 0)
+ return;
+
+ if (!cohd_fin->pending_irqs) {
+ /* release the lli allocation*/
+ coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
+ }
+
+ dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d pending_irqs %d"
+ " nbr_active_done %ld\n", __func__,
+ cohc->id, cohc->pending_irqs, cohc->nbr_active_done);
+
+ /* callback to client */
+ callback = cohd_fin->desc.callback;
+ callback_param = cohd_fin->desc.callback_param;
+
+ if (!cohd_fin->pending_irqs) {
+ coh901318_desc_remove(cohd_fin);
+
+ /* return desc to free-list */
+ coh901318_desc_free(cohc, cohd_fin);
+ }
+
+ if (cohc->nbr_active_done)
+ cohc->nbr_active_done--;
+
+ if (cohc->nbr_active_done) {
+ if (cohc_chan_conf(cohc)->priority_high)
+ tasklet_hi_schedule(&cohc->tasklet);
+ else
+ tasklet_schedule(&cohc->tasklet);
+ }
+ spin_unlock_irqrestore(&cohc->lock, flags);
+
+ if (callback)
+ callback(callback_param);
+
+ return;
+
+ err:
+ spin_unlock_irqrestore(&cohc->lock, flags);
+ dev_err(COHC_2_DEV(cohc), "[%s] No active dma desc\n", __func__);
+}
+
+
+/* called from interrupt context */
+static void dma_tc_handle(struct coh901318_chan *cohc)
+{
+ BUG_ON(!cohc->allocated && (list_empty(&cohc->active) ||
+ list_empty(&cohc->queue)));
+
+ if (!cohc->allocated)
+ return;
+
+ BUG_ON(cohc->pending_irqs == 0);
+
+ cohc->pending_irqs--;
+ cohc->nbr_active_done++;
+
+ if (cohc->pending_irqs == 0 && coh901318_queue_start(cohc) == NULL)
+ cohc->busy = 0;
+
+ BUG_ON(list_empty(&cohc->active));
+
+ if (cohc_chan_conf(cohc)->priority_high)
+ tasklet_hi_schedule(&cohc->tasklet);
+ else
+ tasklet_schedule(&cohc->tasklet);
+}
+
+
+static irqreturn_t dma_irq_handler(int irq, void *dev_id)
+{
+ u32 status1;
+ u32 status2;
+ int i;
+ int ch;
+ struct coh901318_base *base = dev_id;
+ struct coh901318_chan *cohc;
+ void __iomem *virtbase = base->virtbase;
+
+ status1 = readl(virtbase + COH901318_INT_STATUS1);
+ status2 = readl(virtbase + COH901318_INT_STATUS2);
+
+ if (unlikely(status1 == 0 && status2 == 0)) {
+ dev_warn(base->dev, "spurious DMA IRQ from no channel!\n");
+ return IRQ_HANDLED;
+ }
+
+ /* TODO: consider handle IRQ in tasklet here to
+ * minimize interrupt latency */
+
+ /* Check the first 32 DMA channels for IRQ */
+ while (status1) {
+ /* Find first bit set, return as a number. */
+ i = ffs(status1) - 1;
+ ch = i;
+
+ cohc = &base->chans[ch];
+ spin_lock(&cohc->lock);
+
+ /* Mask off this bit */
+ status1 &= ~(1 << i);
+ /* Check the individual channel bits */
+ if (test_bit(i, virtbase + COH901318_BE_INT_STATUS1)) {
+ dev_crit(COHC_2_DEV(cohc),
+ "DMA bus error on channel %d!\n", ch);
+ BUG_ON(1);
+ /* Clear BE interrupt */
+ __set_bit(i, virtbase + COH901318_BE_INT_CLEAR1);
+ } else {
+ /* Caused by TC, really? */
+ if (unlikely(!test_bit(i, virtbase +
+ COH901318_TC_INT_STATUS1))) {
+ dev_warn(COHC_2_DEV(cohc),
+ "ignoring interrupt not caused by terminal count on channel %d\n", ch);
+ /* Clear TC interrupt */
+ BUG_ON(1);
+ __set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
+ } else {
+ /* Enable powersave if transfer has finished */
+ if (!(readl(virtbase + COH901318_CX_STAT +
+ COH901318_CX_STAT_SPACING*ch) &
+ COH901318_CX_STAT_ENABLED)) {
+ enable_powersave(cohc);
+ }
+
+ /* Must clear TC interrupt before calling
+ * dma_tc_handle
+ * in case tc_handle initate a new dma job
+ */
+ __set_bit(i, virtbase + COH901318_TC_INT_CLEAR1);
+
+ dma_tc_handle(cohc);
+ }
+ }
+ spin_unlock(&cohc->lock);
+ }
+
+ /* Check the remaining 32 DMA channels for IRQ */
+ while (status2) {
+ /* Find first bit set, return as a number. */
+ i = ffs(status2) - 1;
+ ch = i + 32;
+ cohc = &base->chans[ch];
+ spin_lock(&cohc->lock);
+
+ /* Mask off this bit */
+ status2 &= ~(1 << i);
+ /* Check the individual channel bits */
+ if (test_bit(i, virtbase + COH901318_BE_INT_STATUS2)) {
+ dev_crit(COHC_2_DEV(cohc),
+ "DMA bus error on channel %d!\n", ch);
+ /* Clear BE interrupt */
+ BUG_ON(1);
+ __set_bit(i, virtbase + COH901318_BE_INT_CLEAR2);
+ } else {
+ /* Caused by TC, really? */
+ if (unlikely(!test_bit(i, virtbase +
+ COH901318_TC_INT_STATUS2))) {
+ dev_warn(COHC_2_DEV(cohc),
+ "ignoring interrupt not caused by terminal count on channel %d\n", ch);
+ /* Clear TC interrupt */
+ __set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
+ BUG_ON(1);
+ } else {
+ /* Enable powersave if transfer has finished */
+ if (!(readl(virtbase + COH901318_CX_STAT +
+ COH901318_CX_STAT_SPACING*ch) &
+ COH901318_CX_STAT_ENABLED)) {
+ enable_powersave(cohc);
+ }
+ /* Must clear TC interrupt before calling
+ * dma_tc_handle
+ * in case tc_handle initate a new dma job
+ */
+ __set_bit(i, virtbase + COH901318_TC_INT_CLEAR2);
+
+ dma_tc_handle(cohc);
+ }
+ }
+ spin_unlock(&cohc->lock);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int coh901318_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+
+ dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d\n",
+ __func__, cohc->id);
+
+ if (chan->client_count > 1)
+ return -EBUSY;
+
+ coh901318_config(cohc, NULL);
+
+ cohc->allocated = 1;
+ cohc->completed = chan->cookie = 1;
+
+ return 1;
+}
+
+static void
+coh901318_free_chan_resources(struct dma_chan *chan)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ int channel = cohc->id;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* Disable HW */
+ writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CFG +
+ COH901318_CX_CFG_SPACING*channel);
+ writel(0x00000000U, cohc->base->virtbase + COH901318_CX_CTRL +
+ COH901318_CX_CTRL_SPACING*channel);
+
+ cohc->allocated = 0;
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+
+ chan->device->device_terminate_all(chan);
+}
+
+
+static dma_cookie_t
+coh901318_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct coh901318_desc *cohd = container_of(tx, struct coh901318_desc,
+ desc);
+ struct coh901318_chan *cohc = to_coh901318_chan(tx->chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ tx->cookie = coh901318_assign_cookie(cohc, cohd);
+
+ coh901318_desc_queue(cohc, cohd);
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+
+ return tx->cookie;
+}
+
+static struct dma_async_tx_descriptor *
+coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+ size_t size, unsigned long flags)
+{
+ struct coh901318_lli *data;
+ struct coh901318_desc *cohd;
+ unsigned long flg;
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ int lli_len;
+ u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+
+ spin_lock_irqsave(&cohc->lock, flg);
+
+ dev_vdbg(COHC_2_DEV(cohc),
+ "[%s] channel %d src 0x%x dest 0x%x size %d\n",
+ __func__, cohc->id, src, dest, size);
+
+ if (flags & DMA_PREP_INTERRUPT)
+ /* Trigger interrupt after last lli */
+ ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
+
+ lli_len = size >> MAX_DMA_PACKET_SIZE_SHIFT;
+ if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
+ lli_len++;
+
+ data = coh901318_lli_alloc(&cohc->base->pool, lli_len);
+
+ if (data == NULL)
+ goto err;
+
+ cohd = coh901318_desc_get(cohc);
+ cohd->sg = NULL;
+ cohd->sg_len = 0;
+ cohd->data = data;
+
+ cohd->pending_irqs =
+ coh901318_lli_fill_memcpy(
+ &cohc->base->pool, data, src, size, dest,
+ cohc_chan_param(cohc)->ctrl_lli_chained,
+ ctrl_last);
+ cohd->flags = flags;
+
+ COH_DBG(coh901318_list_print(cohc, data));
+
+ dma_async_tx_descriptor_init(&cohd->desc, chan);
+
+ cohd->desc.tx_submit = coh901318_tx_submit;
+
+ spin_unlock_irqrestore(&cohc->lock, flg);
+
+ return &cohd->desc;
+ err:
+ spin_unlock_irqrestore(&cohc->lock, flg);
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_data_direction direction,
+ unsigned long flags)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ struct coh901318_lli *data;
+ struct coh901318_desc *cohd;
+ struct scatterlist *sg;
+ int len = 0;
+ int size;
+ int i;
+ u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
+ u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
+ u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+ unsigned long flg;
+
+ if (!sgl)
+ goto out;
+ if (sgl->length == 0)
+ goto out;
+
+ spin_lock_irqsave(&cohc->lock, flg);
+
+ dev_vdbg(COHC_2_DEV(cohc), "[%s] sg_len %d dir %d\n",
+ __func__, sg_len, direction);
+
+ if (flags & DMA_PREP_INTERRUPT)
+ /* Trigger interrupt after last lli */
+ ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
+
+ cohd = coh901318_desc_get(cohc);
+ cohd->sg = NULL;
+ cohd->sg_len = 0;
+ cohd->dir = direction;
+
+ if (direction == DMA_TO_DEVICE) {
+ u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
+ COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
+
+ ctrl_chained |= tx_flags;
+ ctrl_last |= tx_flags;
+ ctrl |= tx_flags;
+ } else if (direction == DMA_FROM_DEVICE) {
+ u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
+ COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
+
+ ctrl_chained |= rx_flags;
+ ctrl_last |= rx_flags;
+ ctrl |= rx_flags;
+ } else
+ goto err_direction;
+
+ dma_async_tx_descriptor_init(&cohd->desc, chan);
+
+ cohd->desc.tx_submit = coh901318_tx_submit;
+
+
+ /* The dma only supports transmitting packages up to
+ * MAX_DMA_PACKET_SIZE. Calculate to total number of
+ * dma elemts required to send the entire sg list
+ */
+ for_each_sg(sgl, sg, sg_len, i) {
+ unsigned int factor;
+ size = sg_dma_len(sg);
+
+ if (size <= MAX_DMA_PACKET_SIZE) {
+ len++;
+ continue;
+ }
+
+ factor = size >> MAX_DMA_PACKET_SIZE_SHIFT;
+ if ((factor << MAX_DMA_PACKET_SIZE_SHIFT) < size)
+ factor++;
+
+ len += factor;
+ }
+
+ data = coh901318_lli_alloc(&cohc->base->pool, len);
+
+ if (data == NULL)
+ goto err_dma_alloc;
+
+ /* initiate allocated data list */
+ cohd->pending_irqs =
+ coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
+ cohc_dev_addr(cohc),
+ ctrl_chained,
+ ctrl,
+ ctrl_last,
+ direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
+ cohd->data = data;
+
+ cohd->flags = flags;
+
+ COH_DBG(coh901318_list_print(cohc, data));
+
+ spin_unlock_irqrestore(&cohc->lock, flg);
+
+ return &cohd->desc;
+ err_dma_alloc:
+ err_direction:
+ coh901318_desc_remove(cohd);
+ coh901318_desc_free(cohc, cohd);
+ spin_unlock_irqrestore(&cohc->lock, flg);
+ out:
+ return NULL;
+}
+
+static enum dma_status
+coh901318_is_tx_complete(struct dma_chan *chan,
+ dma_cookie_t cookie, dma_cookie_t *done,
+ dma_cookie_t *used)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ dma_cookie_t last_used;
+ dma_cookie_t last_complete;
+ int ret;
+
+ last_complete = cohc->completed;
+ last_used = chan->cookie;
+
+ ret = dma_async_is_complete(cookie, last_complete, last_used);
+
+ if (done)
+ *done = last_complete;
+ if (used)
+ *used = last_used;
+
+ return ret;
+}
+
+static void
+coh901318_issue_pending(struct dma_chan *chan)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ unsigned long flags;
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* Busy means that pending jobs are already being processed */
+ if (!cohc->busy)
+ coh901318_queue_start(cohc);
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+}
+
+static void
+coh901318_terminate_all(struct dma_chan *chan)
+{
+ unsigned long flags;
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ struct coh901318_desc *cohd;
+ void __iomem *virtbase = cohc->base->virtbase;
+
+ coh901318_stop(chan);
+
+ spin_lock_irqsave(&cohc->lock, flags);
+
+ /* Clear any pending BE or TC interrupt */
+ if (cohc->id < 32) {
+ writel(1 << cohc->id, virtbase + COH901318_BE_INT_CLEAR1);
+ writel(1 << cohc->id, virtbase + COH901318_TC_INT_CLEAR1);
+ } else {
+ writel(1 << (cohc->id - 32), virtbase +
+ COH901318_BE_INT_CLEAR2);
+ writel(1 << (cohc->id - 32), virtbase +
+ COH901318_TC_INT_CLEAR2);
+ }
+
+ enable_powersave(cohc);
+
+ while ((cohd = coh901318_first_active_get(cohc))) {
+ /* release the lli allocation*/
+ coh901318_lli_free(&cohc->base->pool, &cohd->data);
+
+ coh901318_desc_remove(cohd);
+
+ /* return desc to free-list */
+ coh901318_desc_free(cohc, cohd);
+ }
+
+ while ((cohd = coh901318_first_queued(cohc))) {
+ /* release the lli allocation*/
+ coh901318_lli_free(&cohc->base->pool, &cohd->data);
+
+ coh901318_desc_remove(cohd);
+
+ /* return desc to free-list */
+ coh901318_desc_free(cohc, cohd);
+ }
+
+
+ cohc->nbr_active_done = 0;
+ cohc->busy = 0;
+ cohc->pending_irqs = 0;
+
+ spin_unlock_irqrestore(&cohc->lock, flags);
+}
+void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
+ struct coh901318_base *base)
+{
+ int chans_i;
+ int i = 0;
+ struct coh901318_chan *cohc;
+
+ INIT_LIST_HEAD(&dma->channels);
+
+ for (chans_i = 0; pick_chans[chans_i] != -1; chans_i += 2) {
+ for (i = pick_chans[chans_i]; i <= pick_chans[chans_i+1]; i++) {
+ cohc = &base->chans[i];
+
+ cohc->base = base;
+ cohc->chan.device = dma;
+ cohc->id = i;
+
+ /* TODO: do we really need this lock if only one
+ * client is connected to each channel?
+ */
+
+ spin_lock_init(&cohc->lock);
+
+ cohc->pending_irqs = 0;
+ cohc->nbr_active_done = 0;
+ cohc->busy = 0;
+ INIT_LIST_HEAD(&cohc->free);
+ INIT_LIST_HEAD(&cohc->active);
+ INIT_LIST_HEAD(&cohc->queue);
+
+ tasklet_init(&cohc->tasklet, dma_tasklet,
+ (unsigned long) cohc);
+
+ list_add_tail(&cohc->chan.device_node,
+ &dma->channels);
+ }
+ }
+}
+
+static int __init coh901318_probe(struct platform_device *pdev)
+{
+ int err = 0;
+ struct coh901318_platform *pdata;
+ struct coh901318_base *base;
+ int irq;
+ struct resource *io;
+
+ io = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!io)
+ goto err_get_resource;
+
+ /* Map DMA controller registers to virtual memory */
+ if (request_mem_region(io->start,
+ resource_size(io),
+ pdev->dev.driver->name) == NULL) {
+ err = -EBUSY;
+ goto err_request_mem;
+ }
+
+ pdata = pdev->dev.platform_data;
+ if (!pdata)
+ goto err_no_platformdata;
+
+ base = kmalloc(ALIGN(sizeof(struct coh901318_base), 4) +
+ pdata->max_channels *
+ sizeof(struct coh901318_chan),
+ GFP_KERNEL);
+ if (!base)
+ goto err_alloc_coh_dma_channels;
+
+ base->chans = ((void *)base) + ALIGN(sizeof(struct coh901318_base), 4);
+
+ base->virtbase = ioremap(io->start, resource_size(io));
+ if (!base->virtbase) {
+ err = -ENOMEM;
+ goto err_no_ioremap;
+ }
+
+ base->dev = &pdev->dev;
+ base->platform = pdata;
+ spin_lock_init(&base->pm.lock);
+ base->pm.started_channels = 0;
+
+ COH901318_DEBUGFS_ASSIGN(debugfs_dma_base, base);
+
+ platform_set_drvdata(pdev, base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ goto err_no_irq;
+
+ err = request_irq(irq, dma_irq_handler, IRQF_DISABLED,
+ "coh901318", base);
+ if (err) {
+ dev_crit(&pdev->dev,
+ "Cannot allocate IRQ for DMA controller!\n");
+ goto err_request_irq;
+ }
+
+ err = coh901318_pool_create(&base->pool, &pdev->dev,
+ sizeof(struct coh901318_lli),
+ 32);
+ if (err)
+ goto err_pool_create;
+
+ /* init channels for device transfers */
+ coh901318_base_init(&base->dma_slave, base->platform->chans_slave,
+ base);
+
+ dma_cap_zero(base->dma_slave.cap_mask);
+ dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);
+
+ base->dma_slave.device_alloc_chan_resources = coh901318_alloc_chan_resources;
+ base->dma_slave.device_free_chan_resources = coh901318_free_chan_resources;
+ base->dma_slave.device_prep_slave_sg = coh901318_prep_slave_sg;
+ base->dma_slave.device_is_tx_complete = coh901318_is_tx_complete;
+ base->dma_slave.device_issue_pending = coh901318_issue_pending;
+ base->dma_slave.device_terminate_all = coh901318_terminate_all;
+ base->dma_slave.dev = &pdev->dev;
+
+ err = dma_async_device_register(&base->dma_slave);
+
+ if (err)
+ goto err_register_slave;
+
+ /* init channels for memcpy */
+ coh901318_base_init(&base->dma_memcpy, base->platform->chans_memcpy,
+ base);
+
+ dma_cap_zero(base->dma_memcpy.cap_mask);
+ dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
+
+ base->dma_memcpy.device_alloc_chan_resources = coh901318_alloc_chan_resources;
+ base->dma_memcpy.device_free_chan_resources = coh901318_free_chan_resources;
+ base->dma_memcpy.device_prep_dma_memcpy = coh901318_prep_memcpy;
+ base->dma_memcpy.device_is_tx_complete = coh901318_is_tx_complete;
+ base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
+ base->dma_memcpy.device_terminate_all = coh901318_terminate_all;
+ base->dma_memcpy.dev = &pdev->dev;
+ err = dma_async_device_register(&base->dma_memcpy);
+
+ if (err)
+ goto err_register_memcpy;
+
+ dev_dbg(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
+ (u32) base->virtbase);
+
+ return err;
+
+ err_register_memcpy:
+ dma_async_device_unregister(&base->dma_slave);
+ err_register_slave:
+ coh901318_pool_destroy(&base->pool);
+ err_pool_create:
+ free_irq(platform_get_irq(pdev, 0), base);
+ err_request_irq:
+ err_no_irq:
+ iounmap(base->virtbase);
+ err_no_ioremap:
+ kfree(base);
+ err_alloc_coh_dma_channels:
+ err_no_platformdata:
+ release_mem_region(pdev->resource->start,
+ resource_size(pdev->resource));
+ err_request_mem:
+ err_get_resource:
+ return err;
+}
+
+static int __exit coh901318_remove(struct platform_device *pdev)
+{
+ struct coh901318_base *base = platform_get_drvdata(pdev);
+
+ dma_async_device_unregister(&base->dma_memcpy);
+ dma_async_device_unregister(&base->dma_slave);
+ coh901318_pool_destroy(&base->pool);
+ free_irq(platform_get_irq(pdev, 0), base);
+ kfree(base);
+ iounmap(base->virtbase);
+ release_mem_region(pdev->resource->start,
+ resource_size(pdev->resource));
+ return 0;
+}
+
+
+static struct platform_driver coh901318_driver = {
+ .remove = __exit_p(coh901318_remove),
+ .driver = {
+ .name = "coh901318",
+ },
+};
+
+int __init coh901318_init(void)
+{
+ return platform_driver_probe(&coh901318_driver, coh901318_probe);
+}
+subsys_initcall(coh901318_init);
+
+void __exit coh901318_exit(void)
+{
+ platform_driver_unregister(&coh901318_driver);
+}
+module_exit(coh901318_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Per Friden");