On Mon, 2012-06-04 at 14:37 +0800, Zhangfei Gao wrote:

Add support for two-channel dma under dmaengine
support: mmp-adma and pxa910-squ

Signed-off-by: Zhangfei Gao <redacted>
Signed-off-by: Leo Yan <redacted>
Signed-off-by: Qiao Zhou <redacted>

+
+static int mmp_tdma_clear_chan_irq(struct mmp_tdma_chan *tdmac)
+{
+	u32 reg = readl(tdmac->reg_base + TDISR);
+
+	if (reg & TDISR_COMP) {
+		/* clear irq */
+		reg &= ~TDISR_COMP;
+		writel(reg, tdmac->reg_base + TDISR);
+
+		return 1;

hrmm.?

+	}
+	return 0;
+}
+
+static irqreturn_t mmp_tdma_chan_handler(int irq, void *dev_id)
+{
+	struct mmp_tdma_chan *tdmac = dev_id;
+
+	if (mmp_tdma_clear_chan_irq(tdmac)) {
+		tdmac->pos = (tdmac->pos + tdmac->period_len) % tdmac->buf_len;
+		tasklet_schedule(&tdmac->tasklet);
+		return IRQ_HANDLED;
+	} else
+		return IRQ_NONE;
+}
+
+static irqreturn_t mmp_tdma_int_handler(int irq, void *dev_id)
+{
+	struct mmp_tdma_device *tdev = dev_id;
+	int i, ret;
+	int irq_num = 0;
+
+	for (i = 0; i < TDMA_CHANNEL_NUM; i++) {
+		struct mmp_tdma_chan *tdmac = tdev->tdmac[i];
+
+		ret = mmp_tdma_chan_handler(irq, tdmac);
+		if (ret == IRQ_HANDLED)
+			irq_num++;
+	}
+
+	if (irq_num)
+		return IRQ_HANDLED;
+	else
+		return IRQ_NONE;
+}
+
+static void dma_do_tasklet(unsigned long data)
+{
+	struct mmp_tdma_chan *tdmac = (struct mmp_tdma_chan *)data;
+
+	if (tdmac->desc.callback)
+		tdmac->desc.callback(tdmac->desc.callback_param);
+
+}
+
+static void mmp_tdma_free_descriptor(struct mmp_tdma_chan *tdmac)
+{
+	struct gen_pool *gpool;
+	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
+
+	gpool = sram_get_gpool("asram");
+	if (tdmac->desc_arr)
+		gen_pool_free(gpool, (unsigned long)tdmac->desc_arr,
+				size);
+	tdmac->desc_arr = NULL;
+
+	return;
+}
+
+static dma_cookie_t mmp_tdma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(tx->chan);
+
+	mmp_tdma_chan_set_desc(tdmac, tdmac->desc_arr_phys);

This seems odd. In submit you are supposed to move this to your pending
list. Btw where is the .issue_pending handler?

+
+	return 0;
+}
+
+static int mmp_tdma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+	int ret;
+
+	dev_dbg(tdmac->dev, "%s: enter\n", __func__);
+
+	dma_async_tx_descriptor_init(&tdmac->desc, chan);
+	tdmac->desc.tx_submit = mmp_tdma_tx_submit;
+
+	if (tdmac->irq) {
+		ret = devm_request_irq(tdmac->dev, tdmac->irq,
+			mmp_tdma_chan_handler, IRQF_DISABLED, "tdma", tdmac);
+		if (ret)
+			goto err_request_irq;
+	}
+
+	return 0;

NO. This is supposed to return the number of descriptors allocated.

+
+err_request_irq:
+	mmp_tdma_free_descriptor(tdmac);
+	return ret;
+}
+
+static void mmp_tdma_free_chan_resources(struct dma_chan *chan)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+
+	dev_dbg(tdmac->dev, "%s: enter\n", __func__);
+
+	if (tdmac->irq)
+		devm_free_irq(tdmac->dev, tdmac->irq, tdmac);
+	mmp_tdma_disable_chan(tdmac);

channel should be already disabled, why do you need this here?

+	mmp_tdma_free_descriptor(tdmac);
+	return;
+}
+
+
+static struct dma_async_tx_descriptor *mmp_tdma_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
+{
+	/*
+	 * This operation is not supported on the TDMA controller
+	 *
+	 * However, we need to provide the function pointer to allow the
+	 * device_control() method to work.
+	 */
+	return NULL;
+}

Pls remove if not supported

+
+static int mmp_tdma_alloc_descriptor(struct mmp_tdma_chan *tdmac)
+{
+	struct gen_pool *gpool;
+	int size = tdmac->desc_num * sizeof(struct mmp_tdma_desc);
+
+	dev_dbg(tdmac->dev, "%s: enter\n", __func__);
+
+	gpool = sram_get_gpool("asram");
+	if (!gpool)
+		return -ENOMEM;
+
+	tdmac->desc_arr = (void *)gen_pool_alloc(gpool, size);
+	if (!tdmac->desc_arr)
+		return -ENOMEM;
+
+	tdmac->desc_arr_phys = gen_pool_virt_to_phys(gpool,
+			(unsigned long)tdmac->desc_arr);
+
+	return 0;

this needs fix

+}
+
+static struct dma_async_tx_descriptor *mmp_tdma_prep_dma_cyclic(
+		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+		size_t period_len, enum dma_transfer_direction direction,
+		void *context)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+	int num_periods = buf_len / period_len;
+	int i = 0, buf = 0;
+	int ret;
+
+	if (tdmac->status != DMA_SUCCESS)
+		return NULL;
+
+	if (period_len > TDMA_MAX_XFER_BYTES) {
+		dev_err(tdmac->dev,
+				"maximum period size exceeded: %d > %d\n",
+				period_len, TDMA_MAX_XFER_BYTES);
+		goto err_out;
+	}
+
+	tdmac->status = DMA_IN_PROGRESS;

???

+	tdmac->desc_num = num_periods;
+	ret = mmp_tdma_alloc_descriptor(tdmac);
+	if (ret < 0)
+		goto err_out;
+
+	while (buf < buf_len) {
+		struct mmp_tdma_desc *desc = &tdmac->desc_arr[i];

what if i call prepare twice on the same channel?
Better way would to manage a descriptor list, see other drivers for
examples.

+
+		if (i + 1 == num_periods)
+			desc->nxt_desc = tdmac->desc_arr_phys;
+		else
+			desc->nxt_desc = tdmac->desc_arr_phys +
+				sizeof(*desc) * (i + 1);

pls use kernel link list, it is provided to you so that you dont have to
do above.

+
+		if (direction == DMA_MEM_TO_DEV) {
+			desc->src_addr = dma_addr;
+			desc->dst_addr = tdmac->dev_addr;
+		} else {
+			desc->src_addr = tdmac->dev_addr;
+			desc->dst_addr = dma_addr;
+		}
+		desc->byte_cnt = period_len;
+		dma_addr += period_len;
+		buf += period_len;
+		i++;
+	}
+
+	tdmac->buf_len = buf_len;
+	tdmac->period_len = period_len;
+	tdmac->pos = 0;
+
+	return &tdmac->desc;
+
+err_out:
+	tdmac->status = DMA_ERROR;
+	return NULL;
+}
+
+static int mmp_tdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+		unsigned long arg)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+	struct dma_slave_config *dmaengine_cfg = (void *)arg;
+	int ret = 0;
+
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		mmp_tdma_disable_chan(tdmac);
+		break;
+	case DMA_PAUSE:
+		mmp_tdma_pause_chan(tdmac);
+		break;
+	case DMA_RESUME:
+		mmp_tdma_resume_chan(tdmac);
+		break;
+	case DMA_SLAVE_CONFIG:
+		if (dmaengine_cfg->direction == DMA_DEV_TO_MEM) {
+			tdmac->dev_addr = dmaengine_cfg->src_addr;
+			tdmac->burst_sz = dmaengine_cfg->src_maxburst;
+		} else {
+			tdmac->dev_addr = dmaengine_cfg->dst_addr;
+			tdmac->burst_sz = dmaengine_cfg->dst_maxburst;
+		}
+		tdmac->dir = dmaengine_cfg->direction;
+		return mmp_tdma_config_chan(tdmac);
+	default:
+		ret = -ENOSYS;
+	}
+
+	return ret;
+}
+
+static enum dma_status mmp_tdma_tx_status(struct dma_chan *chan,
+			dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+
+	dma_set_residue(txstate, tdmac->buf_len - tdmac->pos);
+
+	return tdmac->status;
+}
+
+static void mmp_tdma_issue_pending(struct dma_chan *chan)
+{
+	struct mmp_tdma_chan *tdmac = to_mmp_tdma_chan(chan);
+
+	mmp_tdma_enable_chan(tdmac);

can you queue the descriptors here? That was purpose to have separate
issue pending and submit.

+}
+
+static int __devexit mmp_tdma_remove(struct platform_device *pdev)
+{
+	struct mmp_tdma_device *tdev = platform_get_drvdata(pdev);
+
+	dma_async_device_unregister(&tdev->device);
+	return 0;
+}
+
+static int __devinit mmp_tdma_chan_init(struct mmp_tdma_device *tdev,
+						int idx, int irq, int type)
+{
+	struct mmp_tdma_chan *tdmac;
+
+	if (idx >= TDMA_CHANNEL_NUM) {
+		dev_err(tdev->dev, "too many channels for device!\n");
+		return -EINVAL;
+	}
+
+	/* alloc channel */
+	tdmac = devm_kzalloc(tdev->dev, sizeof(*tdmac), GFP_KERNEL);
+	if (!tdmac) {
+		dev_err(tdev->dev, "no free memory for DMA channels!\n");
+		return -ENOMEM;
+	}
+	if (irq)
+		tdmac->irq = irq + idx;
+	tdmac->dev	   = tdev->dev;
+	tdmac->chan.device = &tdev->device;
+	tdmac->idx	   = idx;
+	tdmac->type	   = type;
+	tdmac->reg_base	   = (unsigned long)tdev->base + idx * 4;
+	tdmac->status = DMA_SUCCESS;
+	tdev->tdmac[tdmac->idx] = tdmac;
+	tasklet_init(&tdmac->tasklet, dma_do_tasklet, (unsigned long)tdmac);
+
+	/* add the channel to tdma_chan list */
+	list_add_tail(&tdmac->chan.device_node,
+			&tdev->device.channels);
+
+	return 0;
+}
+
+static int __devinit mmp_tdma_probe(struct platform_device *pdev)
+{
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+	enum mmp_tdma_type type = id->driver_data;
+	struct mmp_tdma_device *tdev;
+	struct resource *iores;
+	int i, ret;
+	int irq = 0;
+	int chan_num = TDMA_CHANNEL_NUM;
+
+	/* always have couple channels */
+	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
+	if (!tdev)
+		return -ENOMEM;
+
+	tdev->dev = &pdev->dev;
+	iores = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!iores)
+		return -EINVAL;
+
+	if (resource_size(iores) != chan_num)
+		tdev->irq = iores->start;
+	else
+		irq = iores->start;
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!iores)
+		return -EINVAL;
+
+	tdev->base = devm_request_and_ioremap(&pdev->dev, iores);
+	if (!tdev->base)
+		return -EADDRNOTAVAIL;
+
+	if (tdev->irq) {
+		ret = devm_request_irq(&pdev->dev, tdev->irq,
+			mmp_tdma_int_handler, IRQF_DISABLED, "tdma", tdev);
+		if (ret)
+			return ret;
+	}
+
+	dma_cap_set(DMA_SLAVE, tdev->device.cap_mask);
+	dma_cap_set(DMA_CYCLIC, tdev->device.cap_mask);
+
+	INIT_LIST_HEAD(&tdev->device.channels);
+
+	/* initialize channel parameters */
+	for (i = 0; i < chan_num; i++) {
+		ret = mmp_tdma_chan_init(tdev, i, irq, type);
+		if (ret)
+			return ret;
+	}
+
+	tdev->device.dev = &pdev->dev;
+	tdev->device.device_alloc_chan_resources =
+					mmp_tdma_alloc_chan_resources;
+	tdev->device.device_free_chan_resources =
+					mmp_tdma_free_chan_resources;
+	tdev->device.device_prep_slave_sg = mmp_tdma_prep_slave_sg;
+	tdev->device.device_prep_dma_cyclic = mmp_tdma_prep_dma_cyclic;
+	tdev->device.device_tx_status = mmp_tdma_tx_status;
+	tdev->device.device_issue_pending = mmp_tdma_issue_pending;
+	tdev->device.device_control = mmp_tdma_control;
+	tdev->device.copy_align = TDMA_ALIGNMENT;
+
+	dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
+	platform_set_drvdata(pdev, tdev);
+
+	ret = dma_async_device_register(&tdev->device);
+	if (ret) {
+		dev_err(tdev->device.dev, "unable to register\n");
+		return ret;
+	}
+
+	dev_info(tdev->device.dev, "initialized\n");
+	return 0;
+}
+
+static const struct platform_device_id mmp_tdma_id_table[] = {
+	{ "mmp-adma",	MMP_AUD_TDMA },
+	{ "pxa910-squ",	PXA910_SQU },
+	{ },
+};
+
+static struct platform_driver mmp_tdma_driver = {
+	.driver		= {
+		.name	= "mmp-tdma",
+		.owner  = THIS_MODULE,
+	},
+	.id_table	= mmp_tdma_id_table,
+	.probe		= mmp_tdma_probe,
+	.remove		= __devexit_p(mmp_tdma_remove),
+};
+
+module_platform_driver(mmp_tdma_driver);
+
+MODULE_DESCRIPTION("MMP Two-Channel DMA Driver");
+MODULE_LICENSE("GPL");

AUTHOR, ALIAS too pls

why do you need separate header for this?


-- 
~Vinod