/*
* Generic PXA PATA driver
*
* Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
*
* 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/ata.h>
#include <linux/libata.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <scsi/scsi_host.h>
#include <mach/pxa2xx-regs.h>
#include <mach/pata_pxa.h>
#include <mach/dma.h>
#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->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,
},
};
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);
