From 2dc6c6f15da97cb3e810963c80e981f19d42cd7d Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Fri, 21 May 2010 03:12:44 +0200 Subject: [ARM] pata_pxa: DMA-capable PATA driver This patch adds a driver for a harddrive attached to PXA address and data bus. Unlike pata_platform, this driver allows usage of PXA DMA controller, making the transmission speed 3x higher. Signed-off-by: Marek Vasut Acked-by: Jeff Garzik Signed-off-by: Eric Miao --- drivers/ata/pata_pxa.c | 411 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 411 insertions(+) create mode 100644 drivers/ata/pata_pxa.c (limited to 'drivers/ata/pata_pxa.c') diff --git a/drivers/ata/pata_pxa.c b/drivers/ata/pata_pxa.c new file mode 100644 index 000000000000..1898c6ed4b4e --- /dev/null +++ b/drivers/ata/pata_pxa.c @@ -0,0 +1,411 @@ +/* + * Generic PXA PATA driver + * + * Copyright (C) 2010 Marek Vasut + * + * 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, 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; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include +#include +#include + +#define DRV_NAME "pata_pxa" +#define DRV_VERSION "0.1" + +struct pata_pxa_data { + uint32_t dma_channel; + struct pxa_dma_desc *dma_desc; + dma_addr_t dma_desc_addr; + uint32_t dma_desc_id; + + /* DMA IO physical address */ + uint32_t dma_io_addr; + /* PXA DREQ<0:2> pin selector */ + uint32_t dma_dreq; + /* DMA DCSR register value */ + uint32_t dma_dcsr; + + struct completion dma_done; +}; + +/* + * Setup the DMA descriptors. The size is transfer capped at 4k per descriptor, + * if the transfer is longer, it is split into multiple chained descriptors. + */ +static void pxa_load_dmac(struct scatterlist *sg, struct ata_queued_cmd *qc) +{ + struct pata_pxa_data *pd = qc->ap->private_data; + + uint32_t cpu_len, seg_len; + dma_addr_t cpu_addr; + + cpu_addr = sg_dma_address(sg); + cpu_len = sg_dma_len(sg); + + do { + seg_len = (cpu_len > 0x1000) ? 0x1000 : cpu_len; + + pd->dma_desc[pd->dma_desc_id].ddadr = pd->dma_desc_addr + + ((pd->dma_desc_id + 1) * sizeof(struct pxa_dma_desc)); + + pd->dma_desc[pd->dma_desc_id].dcmd = DCMD_BURST32 | + DCMD_WIDTH2 | (DCMD_LENGTH & seg_len); + + if (qc->tf.flags & ATA_TFLAG_WRITE) { + pd->dma_desc[pd->dma_desc_id].dsadr = cpu_addr; + pd->dma_desc[pd->dma_desc_id].dtadr = pd->dma_io_addr; + pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCSRCADDR | + DCMD_FLOWTRG; + } else { + pd->dma_desc[pd->dma_desc_id].dsadr = pd->dma_io_addr; + pd->dma_desc[pd->dma_desc_id].dtadr = cpu_addr; + pd->dma_desc[pd->dma_desc_id].dcmd |= DCMD_INCTRGADDR | + DCMD_FLOWSRC; + } + + cpu_len -= seg_len; + cpu_addr += seg_len; + pd->dma_desc_id++; + + } while (cpu_len); + + /* Should not happen */ + if (seg_len & 0x1f) + DALGN |= (1 << pd->dma_dreq); +} + +/* + * Prepare taskfile for submission. + */ +static void pxa_qc_prep(struct ata_queued_cmd *qc) +{ + struct pata_pxa_data *pd = qc->ap->private_data; + int si = 0; + struct scatterlist *sg; + + if (!(qc->flags & ATA_QCFLAG_DMAMAP)) + return; + + pd->dma_desc_id = 0; + + DCSR(pd->dma_channel) = 0; + DALGN &= ~(1 << pd->dma_dreq); + + for_each_sg(qc->sg, sg, qc->n_elem, si) + pxa_load_dmac(sg, qc); + + pd->dma_desc[pd->dma_desc_id - 1].ddadr = DDADR_STOP; + + /* Fire IRQ only at the end of last block */ + pd->dma_desc[pd->dma_desc_id - 1].dcmd |= DCMD_ENDIRQEN; + + DDADR(pd->dma_channel) = pd->dma_desc_addr; + DRCMR(pd->dma_dreq) = DRCMR_MAPVLD | pd->dma_channel; + +} + +/* + * 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); + DCSR(pd->dma_channel) = DCSR_RUN; +} + +/* + * 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; + + if ((DCSR(pd->dma_channel) & DCSR_RUN) && + wait_for_completion_timeout(&pd->dma_done, HZ)) + dev_err(qc->ap->dev, "Timeout waiting for DMA completion!"); + + DCSR(pd->dma_channel) = 0; +} + +/* + * 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; + + if (pd->dma_dcsr & DCSR_BUSERR) + 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, +}; + +/* + * DMA interrupt handler. + */ +static void pxa_ata_dma_irq(int dma, void *port) +{ + struct ata_port *ap = port; + struct pata_pxa_data *pd = ap->private_data; + + pd->dma_dcsr = DCSR(dma); + DCSR(dma) = pd->dma_dcsr; + + if (pd->dma_dcsr & DCSR_STOPSTATE) + complete(&pd->dma_done); +} + +static int __devinit 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 resource *irq_res; + struct pata_pxa_pdata *pdata = pdev->dev.platform_data; + int ret = 0; + + /* + * 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_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (unlikely(irq_res == NULL)) + return -EINVAL; + + /* + * 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->flags = ATA_FLAG_MMIO; + + 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; + data->dma_dreq = pdata->dma_dreq; + data->dma_io_addr = dma_res->start; + + /* + * Allocate space for the DMA descriptors + */ + data->dma_desc = dmam_alloc_coherent(&pdev->dev, PAGE_SIZE, + &data->dma_desc_addr, GFP_KERNEL); + if (!data->dma_desc) + return -EINVAL; + + /* + * Request the DMA channel + */ + data->dma_channel = pxa_request_dma(DRV_NAME, DMA_PRIO_LOW, + pxa_ata_dma_irq, ap); + if (data->dma_channel < 0) + return -EBUSY; + + /* + * Stop and clear the DMA channel + */ + DCSR(data->dma_channel) = 0; + + /* + * Activate the ATA host + */ + ret = ata_host_activate(host, irq_res->start, ata_sff_interrupt, + pdata->irq_flags, &pxa_ata_sht); + if (ret) + pxa_free_dma(data->dma_channel); + + return ret; +} + +static int __devexit pxa_ata_remove(struct platform_device *pdev) +{ + struct ata_host *host = dev_get_drvdata(&pdev->dev); + struct pata_pxa_data *data = host->ports[0]->private_data; + + pxa_free_dma(data->dma_channel); + + ata_host_detach(host); + + return 0; +} + +static struct platform_driver pxa_ata_driver = { + .probe = pxa_ata_probe, + .remove = __devexit_p(pxa_ata_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, +}; + +static int __init pxa_ata_init(void) +{ + return platform_driver_register(&pxa_ata_driver); +} + +static void __exit pxa_ata_exit(void) +{ + platform_driver_unregister(&pxa_ata_driver); +} + +module_init(pxa_ata_init); +module_exit(pxa_ata_exit); + +MODULE_AUTHOR("Marek Vasut "); +MODULE_DESCRIPTION("DMA-capable driver for PATA on PXA CPU"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRV_VERSION); +MODULE_ALIAS("platform:" DRV_NAME); -- cgit