1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/ata/pata_pxa.c b/drivers/ata/pata_pxa.c
new file mode 100644
index 000000000..985f42c4f
--- /dev/null
+++ b/drivers/ata/pata_pxa.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic PXA PATA driver
+ *
+ * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/ata.h>
+#include <linux/libata.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+#include <linux/slab.h>
+#include <linux/completion.h>
+
+#include <scsi/scsi_host.h>
+
+#include <linux/platform_data/ata-pxa.h>
+
+#define DRV_NAME	"pata_pxa"
+#define DRV_VERSION	"0.1"
+
+struct pata_pxa_data {
+	struct dma_chan		*dma_chan;
+	dma_cookie_t		dma_cookie;
+	struct completion	dma_done;
+};
+
+/*
+ * DMA interrupt handler.
+ */
+static void pxa_ata_dma_irq(void *d)
+{
+	struct pata_pxa_data *pd = d;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
+	if (status == DMA_ERROR || status == DMA_COMPLETE)
+		complete(&pd->dma_done);
+}
+
+/*
+ * Prepare taskfile for submission.
+ */
+static enum ata_completion_errors pxa_qc_prep(struct ata_queued_cmd *qc)
+{
+	struct pata_pxa_data *pd = qc->ap->private_data;
+	struct dma_async_tx_descriptor *tx;
+	enum dma_transfer_direction dir;
+
+	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
+		return AC_ERR_OK;
+
+	dir = (qc->dma_dir == DMA_TO_DEVICE ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM);
+	tx = dmaengine_prep_slave_sg(pd->dma_chan, qc->sg, qc->n_elem, dir,
+				     DMA_PREP_INTERRUPT);
+	if (!tx) {
+		ata_dev_err(qc->dev, "prep_slave_sg() failed\n");
+		return AC_ERR_OK;
+	}
+	tx->callback = pxa_ata_dma_irq;
+	tx->callback_param = pd;
+	pd->dma_cookie = dmaengine_submit(tx);
+
+	return AC_ERR_OK;
+}
+
+/*
+ * Configure the DMA controller, load the DMA descriptors, but don't start the
+ * DMA controller yet. Only issue the ATA command.
+ */
+static void pxa_bmdma_setup(struct ata_queued_cmd *qc)
+{
+	qc->ap->ops->sff_exec_command(qc->ap, &qc->tf);
+}
+
+/*
+ * Execute the DMA transfer.
+ */
+static void pxa_bmdma_start(struct ata_queued_cmd *qc)
+{
+	struct pata_pxa_data *pd = qc->ap->private_data;
+	init_completion(&pd->dma_done);
+	dma_async_issue_pending(pd->dma_chan);
+}
+
+/*
+ * Wait until the DMA transfer completes, then stop the DMA controller.
+ */
+static void pxa_bmdma_stop(struct ata_queued_cmd *qc)
+{
+	struct pata_pxa_data *pd = qc->ap->private_data;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, NULL);
+	if (status != DMA_ERROR && status != DMA_COMPLETE &&
+	    wait_for_completion_timeout(&pd->dma_done, HZ))
+		ata_dev_err(qc->dev, "Timeout waiting for DMA completion!");
+
+	dmaengine_terminate_all(pd->dma_chan);
+}
+
+/*
+ * Read DMA status. The bmdma_stop() will take care of properly finishing the
+ * DMA transfer so we always have DMA-complete interrupt here.
+ */
+static unsigned char pxa_bmdma_status(struct ata_port *ap)
+{
+	struct pata_pxa_data *pd = ap->private_data;
+	unsigned char ret = ATA_DMA_INTR;
+	struct dma_tx_state state;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(pd->dma_chan, pd->dma_cookie, &state);
+	if (status != DMA_COMPLETE)
+		ret |= ATA_DMA_ERR;
+
+	return ret;
+}
+
+/*
+ * No IRQ register present so we do nothing.
+ */
+static void pxa_irq_clear(struct ata_port *ap)
+{
+}
+
+/*
+ * Check for ATAPI DMA. ATAPI DMA is unsupported by this driver. It's still
+ * unclear why ATAPI has DMA issues.
+ */
+static int pxa_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+	return -EOPNOTSUPP;
+}
+
+static struct scsi_host_template pxa_ata_sht = {
+	ATA_BMDMA_SHT(DRV_NAME),
+};
+
+static struct ata_port_operations pxa_ata_port_ops = {
+	.inherits		= &ata_bmdma_port_ops,
+	.cable_detect		= ata_cable_40wire,
+
+	.bmdma_setup		= pxa_bmdma_setup,
+	.bmdma_start		= pxa_bmdma_start,
+	.bmdma_stop		= pxa_bmdma_stop,
+	.bmdma_status		= pxa_bmdma_status,
+
+	.check_atapi_dma	= pxa_check_atapi_dma,
+
+	.sff_irq_clear		= pxa_irq_clear,
+
+	.qc_prep		= pxa_qc_prep,
+};
+
+static int pxa_ata_probe(struct platform_device *pdev)
+{
+	struct ata_host *host;
+	struct ata_port *ap;
+	struct pata_pxa_data *data;
+	struct resource *cmd_res;
+	struct resource *ctl_res;
+	struct resource *dma_res;
+	struct pata_pxa_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct dma_slave_config	config;
+	int ret = 0;
+	int irq;
+
+	/*
+	 * Resource validation, three resources are needed:
+	 *  - CMD port base address
+	 *  - CTL port base address
+	 *  - DMA port base address
+	 *  - IRQ pin
+	 */
+	if (pdev->num_resources != 4) {
+		dev_err(&pdev->dev, "invalid number of resources\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * CMD port base address
+	 */
+	cmd_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (unlikely(cmd_res == NULL))
+		return -EINVAL;
+
+	/*
+	 * CTL port base address
+	 */
+	ctl_res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (unlikely(ctl_res == NULL))
+		return -EINVAL;
+
+	/*
+	 * DMA port base address
+	 */
+	dma_res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (unlikely(dma_res == NULL))
+		return -EINVAL;
+
+	/*
+	 * IRQ pin
+	 */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	/*
+	 * Allocate the host
+	 */
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host)
+		return -ENOMEM;
+
+	ap		= host->ports[0];
+	ap->ops		= &pxa_ata_port_ops;
+	ap->pio_mask	= ATA_PIO4;
+	ap->mwdma_mask	= ATA_MWDMA2;
+
+	ap->ioaddr.cmd_addr	= devm_ioremap(&pdev->dev, cmd_res->start,
+						resource_size(cmd_res));
+	ap->ioaddr.ctl_addr	= devm_ioremap(&pdev->dev, ctl_res->start,
+						resource_size(ctl_res));
+	ap->ioaddr.bmdma_addr	= devm_ioremap(&pdev->dev, dma_res->start,
+						resource_size(dma_res));
+
+	/*
+	 * Adjust register offsets
+	 */
+	ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
+	ap->ioaddr.data_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_DATA << pdata->reg_shift);
+	ap->ioaddr.error_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_ERR << pdata->reg_shift);
+	ap->ioaddr.feature_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_FEATURE << pdata->reg_shift);
+	ap->ioaddr.nsect_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_NSECT << pdata->reg_shift);
+	ap->ioaddr.lbal_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_LBAL << pdata->reg_shift);
+	ap->ioaddr.lbam_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_LBAM << pdata->reg_shift);
+	ap->ioaddr.lbah_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_LBAH << pdata->reg_shift);
+	ap->ioaddr.device_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_DEVICE << pdata->reg_shift);
+	ap->ioaddr.status_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_STATUS << pdata->reg_shift);
+	ap->ioaddr.command_addr	= ap->ioaddr.cmd_addr +
+					(ATA_REG_CMD << pdata->reg_shift);
+
+	/*
+	 * Allocate and load driver's internal data structure
+	 */
+	data = devm_kzalloc(&pdev->dev, sizeof(struct pata_pxa_data),
+								GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	ap->private_data = data;
+
+	memset(&config, 0, sizeof(config));
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	config.src_addr = dma_res->start;
+	config.dst_addr = dma_res->start;
+	config.src_maxburst = 32;
+	config.dst_maxburst = 32;
+
+	/*
+	 * Request the DMA channel
+	 */
+	data->dma_chan =
+		dma_request_slave_channel(&pdev->dev, "data");
+	if (!data->dma_chan)
+		return -EBUSY;
+	ret = dmaengine_slave_config(data->dma_chan, &config);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "dma configuration failed: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Activate the ATA host
+	 */
+	ret = ata_host_activate(host, irq, ata_sff_interrupt,
+				pdata->irq_flags, &pxa_ata_sht);
+	if (ret)
+		dma_release_channel(data->dma_chan);
+
+	return ret;
+}
+
+static int pxa_ata_remove(struct platform_device *pdev)
+{
+	struct ata_host *host = platform_get_drvdata(pdev);
+	struct pata_pxa_data *data = host->ports[0]->private_data;
+
+	dma_release_channel(data->dma_chan);
+
+	ata_host_detach(host);
+
+	return 0;
+}
+
+static struct platform_driver pxa_ata_driver = {
+	.probe		= pxa_ata_probe,
+	.remove		= pxa_ata_remove,
+	.driver		= {
+		.name		= DRV_NAME,
+	},
+};
+
+module_platform_driver(pxa_ata_driver);
+
+MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
+MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+MODULE_ALIAS("platform:" DRV_NAME);