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ata: sata_dwc_460ex: use "dmas" DT property to find dma channel
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Currently this driver only works with a DesignWare DMA engine which it
registers manually using the second "reg" address range and interrupt
number from the DT node.

This patch makes the driver instead use the "dmas" property if present,
otherwise optionally falling back on the old way so existing device
trees can continue to work.

With this change, there is no longer any reason to depend on the 460EX
machine type so drop that from Kconfig.

Tested-by: Christian Lamparter <[email protected]>
Signed-off-by: Mans Rullgard <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
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@mansr @htejun
mansr authored and htejun committed May 10, 2016
1 parent 077028e commit 50b4337
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Showing 2 changed files with 138 additions and 71 deletions.
11 changes: 9 additions & 2 deletions drivers/ata/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -305,14 +305,21 @@ config ATA_PIIX

config SATA_DWC
tristate "DesignWare Cores SATA support"
depends on 460EX
select DW_DMAC_CORE
help
This option enables support for the on-chip SATA controller of the
AppliedMicro processor 460EX.

If unsure, say N.

config SATA_DWC_OLD_DMA
bool "Support old device trees"
depends on SATA_DWC
select DW_DMAC_CORE
default y if 460EX
help
This option enables support for old device trees without the
"dmas" property.

config SATA_DWC_DEBUG
bool "Debugging driver version"
depends on SATA_DWC
Expand Down
198 changes: 129 additions & 69 deletions drivers/ata/sata_dwc_460ex.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
Expand All @@ -42,10 +43,6 @@
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>

/* Supported DMA engine drivers */
#include <linux/platform_data/dma-dw.h>
#include <linux/dma/dw.h>

/* These two are defined in "libata.h" */
#undef DRV_NAME
#undef DRV_VERSION
Expand Down Expand Up @@ -148,7 +145,9 @@ struct sata_dwc_device {
struct ata_host *host;
u8 __iomem *reg_base;
struct sata_dwc_regs *sata_dwc_regs; /* DW Synopsys SATA specific */
#ifdef CONFIG_SATA_DWC_OLD_DMA
struct dw_dma_chip *dma;
#endif
};

#define SATA_DWC_QCMD_MAX 32
Expand All @@ -159,7 +158,6 @@ struct sata_dwc_device_port {
int dma_pending[SATA_DWC_QCMD_MAX];

/* DMA info */
struct dw_dma_slave *dws;
struct dma_chan *chan;
struct dma_async_tx_descriptor *desc[SATA_DWC_QCMD_MAX];
u32 dma_interrupt_count;
Expand Down Expand Up @@ -198,13 +196,6 @@ struct sata_dwc_host_priv {

static struct sata_dwc_host_priv host_pvt;

static struct dw_dma_slave sata_dwc_dma_dws = {
.src_id = 0,
.dst_id = 0,
.m_master = 1,
.p_master = 0,
};

/*
* Prototypes
*/
Expand All @@ -215,6 +206,99 @@ static void sata_dwc_dma_xfer_complete(struct ata_port *ap, u32 check_status);
static void sata_dwc_port_stop(struct ata_port *ap);
static void sata_dwc_clear_dmacr(struct sata_dwc_device_port *hsdevp, u8 tag);

#ifdef CONFIG_SATA_DWC_OLD_DMA

#include <linux/platform_data/dma-dw.h>
#include <linux/dma/dw.h>

static struct dw_dma_slave sata_dwc_dma_dws = {
.src_id = 0,
.dst_id = 0,
.m_master = 1,
.p_master = 0,
};

static bool sata_dwc_dma_filter(struct dma_chan *chan, void *param)
{
struct dw_dma_slave *dws = &sata_dwc_dma_dws;

if (dws->dma_dev != chan->device->dev)
return false;

chan->private = dws;
return true;
}

static int sata_dwc_dma_get_channel_old(struct sata_dwc_device_port *hsdevp)
{
struct sata_dwc_device *hsdev = hsdevp->hsdev;
struct dw_dma_slave *dws = &sata_dwc_dma_dws;
dma_cap_mask_t mask;

dws->dma_dev = hsdev->dev;

dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);

/* Acquire DMA channel */
hsdevp->chan = dma_request_channel(mask, sata_dwc_dma_filter, hsdevp);
if (!hsdevp->chan) {
dev_err(hsdev->dev, "%s: dma channel unavailable\n",
__func__);
return -EAGAIN;
}

return 0;
}

static int sata_dwc_dma_init_old(struct platform_device *pdev,
struct sata_dwc_device *hsdev)
{
struct device_node *np = pdev->dev.of_node;
int err;

hsdev->dma = devm_kzalloc(&pdev->dev, sizeof(*hsdev->dma), GFP_KERNEL);
if (!hsdev->dma)
return -ENOMEM;

hsdev->dma->dev = &pdev->dev;

/* Get SATA DMA interrupt number */
hsdev->dma->irq = irq_of_parse_and_map(np, 1);
if (hsdev->dma->irq == NO_IRQ) {
dev_err(&pdev->dev, "no SATA DMA irq\n");
return -ENODEV;
}

/* Get physical SATA DMA register base address */
hsdev->dma->regs = of_iomap(np, 1);
if (!hsdev->dma->regs) {
dev_err(&pdev->dev,
"ioremap failed for AHBDMA register address\n");
return -ENODEV;
}

/* Initialize AHB DMAC */
err = dw_dma_probe(hsdev->dma);
if (err) {
iounmap(hsdev->dma->regs);
return err;
}

return 0;
}

static void sata_dwc_dma_exit_old(struct sata_dwc_device *hsdev)
{
if (!hsdev->dma)
return;

dw_dma_remove(hsdev->dma);
iounmap(hsdev->dma->regs);
}

#endif

static const char *get_prot_descript(u8 protocol)
{
switch ((enum ata_tf_protocols)protocol) {
Expand Down Expand Up @@ -783,18 +867,6 @@ static void sata_dwc_enable_interrupts(struct sata_dwc_device *hsdev)
in_le32(&hsdev->sata_dwc_regs->errmr));
}

static bool sata_dwc_dma_filter(struct dma_chan *chan, void *param)
{
struct sata_dwc_device_port *hsdevp = param;
struct dw_dma_slave *dws = hsdevp->dws;

if (dws->dma_dev != chan->device->dev)
return false;

chan->private = dws;
return true;
}

static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
{
port->cmd_addr = (void __iomem *)base + 0x00;
Expand All @@ -817,6 +889,26 @@ static void sata_dwc_setup_port(struct ata_ioports *port, unsigned long base)
port->ctl_addr = (void __iomem *)base + 0x20;
}

static int sata_dwc_dma_get_channel(struct sata_dwc_device_port *hsdevp)
{
struct sata_dwc_device *hsdev = hsdevp->hsdev;
struct device *dev = hsdev->dev;

#ifdef CONFIG_SATA_DWC_OLD_DMA
if (!of_find_property(dev->of_node, "dmas", NULL))
return sata_dwc_dma_get_channel_old(hsdevp);
#endif

hsdevp->chan = dma_request_chan(dev, "sata-dma");
if (IS_ERR(hsdevp->chan)) {
dev_err(dev, "failed to allocate dma channel: %ld\n",
PTR_ERR(hsdevp->chan));
return PTR_ERR(hsdevp->chan);
}

return 0;
}

/*
* Function : sata_dwc_port_start
* arguments : struct ata_ioports *port
Expand All @@ -829,7 +921,6 @@ static int sata_dwc_port_start(struct ata_port *ap)
struct sata_dwc_device *hsdev;
struct sata_dwc_device_port *hsdevp = NULL;
struct device *pdev;
dma_cap_mask_t mask;
int i;

hsdev = HSDEV_FROM_AP(ap);
Expand All @@ -853,20 +944,9 @@ static int sata_dwc_port_start(struct ata_port *ap)
}
hsdevp->hsdev = hsdev;

hsdevp->dws = &sata_dwc_dma_dws;
hsdevp->dws->dma_dev = hsdev->dev;

dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);

/* Acquire DMA channel */
hsdevp->chan = dma_request_channel(mask, sata_dwc_dma_filter, hsdevp);
if (!hsdevp->chan) {
dev_err(hsdev->dev, "%s: dma channel unavailable\n",
__func__);
err = -EAGAIN;
err = sata_dwc_dma_get_channel(hsdevp);
if (err)
goto CLEANUP_ALLOC;
}

for (i = 0; i < SATA_DWC_QCMD_MAX; i++)
hsdevp->cmd_issued[i] = SATA_DWC_CMD_ISSUED_NOT;
Expand Down Expand Up @@ -1219,33 +1299,9 @@ static int sata_dwc_probe(struct platform_device *ofdev)
dev_notice(&ofdev->dev, "id %d, controller version %c.%c%c\n",
idr, ver[0], ver[1], ver[2]);

/* Get SATA DMA interrupt number */
hsdev->dma->irq = irq_of_parse_and_map(np, 1);
if (hsdev->dma->irq == NO_IRQ) {
dev_err(&ofdev->dev, "no SATA DMA irq\n");
err = -ENODEV;
goto error_iomap;
}

/* Get physical SATA DMA register base address */
hsdev->dma->regs = of_iomap(np, 1);
if (!hsdev->dma->regs) {
dev_err(&ofdev->dev,
"ioremap failed for AHBDMA register address\n");
err = -ENODEV;
goto error_iomap;
}

/* Save dev for later use in dev_xxx() routines */
hsdev->dev = &ofdev->dev;

hsdev->dma->dev = &ofdev->dev;

/* Initialize AHB DMAC */
err = dw_dma_probe(hsdev->dma);
if (err)
goto error_dma_iomap;

/* Enable SATA Interrupts */
sata_dwc_enable_interrupts(hsdev);

Expand All @@ -1257,6 +1313,14 @@ static int sata_dwc_probe(struct platform_device *ofdev)
goto error_out;
}

#ifdef CONFIG_SATA_DWC_OLD_DMA
if (!of_find_property(np, "dmas", NULL)) {
err = sata_dwc_dma_init_old(ofdev, hsdev);
if (err)
goto error_out;
}
#endif

/*
* Now, register with libATA core, this will also initiate the
* device discovery process, invoking our port_start() handler &
Expand All @@ -1270,11 +1334,6 @@ static int sata_dwc_probe(struct platform_device *ofdev)
return 0;

error_out:
/* Free SATA DMA resources */
dw_dma_remove(hsdev->dma);
error_dma_iomap:
iounmap(hsdev->dma->regs);
error_iomap:
iounmap(base);
return err;
}
Expand All @@ -1287,10 +1346,11 @@ static int sata_dwc_remove(struct platform_device *ofdev)

ata_host_detach(host);

#ifdef CONFIG_SATA_DWC_OLD_DMA
/* Free SATA DMA resources */
dw_dma_remove(hsdev->dma);
sata_dwc_dma_exit_old(hsdev);
#endif

iounmap(hsdev->dma->regs);
iounmap(hsdev->reg_base);
dev_dbg(&ofdev->dev, "done\n");
return 0;
Expand Down

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