diff mbox

[v2,1/3] ata: add Palmchip BK3710 PATA controller driver

Message ID 1489509414-11491-2-git-send-email-b.zolnierkie@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Bartlomiej Zolnierkiewicz March 14, 2017, 4:36 p.m. UTC
Add Palmchip BK3710 PATA controller driver.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 drivers/ata/Kconfig       |   9 ++
 drivers/ata/Makefile      |   1 +
 drivers/ata/pata_bk3710.c | 386 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 396 insertions(+)
 create mode 100644 drivers/ata/pata_bk3710.c

Comments

Sergei Shtylyov March 18, 2017, 1:52 p.m. UTC | #1
Hello!

On 3/14/2017 7:36 PM, Bartlomiej Zolnierkiewicz wrote:

> Add Palmchip BK3710 PATA controller driver.
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[...]
> diff --git a/drivers/ata/pata_bk3710.c b/drivers/ata/pata_bk3710.c
> new file mode 100644
> index 0000000..6d77217
> --- /dev/null
> +++ b/drivers/ata/pata_bk3710.c
> @@ -0,0 +1,386 @@
[...]
> +static void pata_bk3710_chipinit(void __iomem *base)
> +{
[...]
> +	/*
> +	 * IORDYTMP IORDY Timer for Primary Register
> +	 * (ATA_IORDYTMP_IORDYTMP     , 0xffff  )
> +	 */
> +	iowrite32(0xFFFF, base + BK3710_IORDYTMP);

    As I've already said, this is useless as we don't handle the IORDY timeout 
interrupt anyway; writing 0 would be fine.

> +
> +	/*
> +	 * Configure BMISP Register
> +	 * (ATA_BMISP_DMAEN1	, DISABLE )	|
> +	 * (ATA_BMISP_DMAEN0	, DISABLE )	|
> +	 * (ATA_BMISP_IORDYINT	, CLEAR)	|
> +	 * (ATA_BMISP_INTRSTAT	, CLEAR)	|
> +	 * (ATA_BMISP_DMAERROR	, CLEAR)
> +	 */
> +	iowrite16(0, base + BK3710_BMISP);

    Bits 0-3 cane only be cleared by writing 1, so this write can't clear 
them, contrary to what the comment says. Might be a material for a follow-up 
patch tho...

[...]
> +static int __init pata_bk3710_probe(struct platform_device *pdev)
> +{
> +	struct clk *clk;
> +	struct resource *mem;
> +	struct ata_host *host;
> +	struct ata_port *ap;
> +	void __iomem *base;
> +	unsigned long rate;
> +	int irq;
> +
> +	clk = devm_clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(clk))
> +		return -ENODEV;
> +
> +	clk_enable(clk);
> +	rate = clk_get_rate(clk);
> +	if (!rate)
> +		return -EINVAL;
> +
> +	/* NOTE:  round *down* to meet minimum timings; we count in clocks */
> +	ideclk_period = 1000000000UL / rate;
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (mem == NULL) {
> +		pr_err(DRV_NAME ": failed to get memory region resource\n");
> +		return -ENODEV;
> +	}

    NULL check not needed here, devm_ioremap_resource() checks this anyway.

> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		pr_err(DRV_NAME ": failed to get IRQ resource\n");
> +		return irq;
> +	}
> +
> +	base = devm_ioremap_resource(&pdev->dev, mem);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
[...]
> +/* work with hotplug and coldplug */
> +MODULE_ALIAS("platform:palm_bk3710");
> +
> +static struct platform_driver pata_bk3710_driver = {
> +	.driver = {
> +		.name = "palm_bk3710",

    Not DRV_NAME?

[...]

MBR, Sergei
Sekhar Nori March 21, 2017, 8:34 a.m. UTC | #2
Hi,

On Tuesday 14 March 2017 10:06 PM, Bartlomiej Zolnierkiewicz wrote:
> Add Palmchip BK3710 PATA controller driver.
> 
> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

There are some checkpatch suggestions that are worth fixing, I think.

[PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:277: CHECK: Alignment should match open parenthesis
[PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:320: CHECK: Alignment should match open parenthesis
[PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:489: CHECK: Comparison to NULL could be written "!mem"

Thanks,
Sekhar
Bartlomiej Zolnierkiewicz March 22, 2017, 5:49 p.m. UTC | #3
Hi,

On Tuesday, March 21, 2017 02:04:38 PM Sekhar Nori wrote:
> Hi,
> 
> On Tuesday 14 March 2017 10:06 PM, Bartlomiej Zolnierkiewicz wrote:
> > Add Palmchip BK3710 PATA controller driver.
> > 
> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> 
> There are some checkpatch suggestions that are worth fixing, I think.
> 
> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:277: CHECK: Alignment should match open parenthesis
> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:320: CHECK: Alignment should match open parenthesis
> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:489: CHECK: Comparison to NULL could be written "!mem"

Will be fixed in v3, thanks.

[ My scripts didn't run checkpatch with --strict so I haven't noticed them. ]

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
Sergei Shtylyov March 22, 2017, 5:56 p.m. UTC | #4
Hello!

On 03/22/2017 08:49 PM, Bartlomiej Zolnierkiewicz wrote:

>>> Add Palmchip BK3710 PATA controller driver.
>>>
>>> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
>>
>> There are some checkpatch suggestions that are worth fixing, I think.
>>
>> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:277: CHECK: Alignment should match open parenthesis
>> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:320: CHECK: Alignment should match open parenthesis
>> [PATCH v2 1_3] ata: add Palmchip BK3710 PATA controller driver - Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2017-03-14 2206.eml:489: CHECK: Comparison to NULL could be written "!mem"
>
> Will be fixed in v3, thanks.
>
> [ My scripts didn't run checkpatch with --strict so I haven't noticed them. ]

   --strict'ly speaking, this switch is only forced on in the networking 
trees. :-)

> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics

MBR, Sergei
Bartlomiej Zolnierkiewicz March 22, 2017, 5:59 p.m. UTC | #5
Hi,

On Saturday, March 18, 2017 04:52:18 PM Sergei Shtylyov wrote:
> Hello!
> 
> On 3/14/2017 7:36 PM, Bartlomiej Zolnierkiewicz wrote:
> 
> > Add Palmchip BK3710 PATA controller driver.
> >
> > Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> [...]
> > diff --git a/drivers/ata/pata_bk3710.c b/drivers/ata/pata_bk3710.c
> > new file mode 100644
> > index 0000000..6d77217
> > --- /dev/null
> > +++ b/drivers/ata/pata_bk3710.c
> > @@ -0,0 +1,386 @@
> [...]
> > +static void pata_bk3710_chipinit(void __iomem *base)
> > +{
> [...]
> > +	/*
> > +	 * IORDYTMP IORDY Timer for Primary Register
> > +	 * (ATA_IORDYTMP_IORDYTMP     , 0xffff  )
> > +	 */
> > +	iowrite32(0xFFFF, base + BK3710_IORDYTMP);
> 
>     As I've already said, this is useless as we don't handle the IORDY timeout 
> interrupt anyway; writing 0 would be fine.

Will fix in v3, in the incremental patch (so it is easier to revert
if it turns out to cause problems later or port to palm_bk3710).

> > +
> > +	/*
> > +	 * Configure BMISP Register
> > +	 * (ATA_BMISP_DMAEN1	, DISABLE )	|
> > +	 * (ATA_BMISP_DMAEN0	, DISABLE )	|
> > +	 * (ATA_BMISP_IORDYINT	, CLEAR)	|
> > +	 * (ATA_BMISP_INTRSTAT	, CLEAR)	|
> > +	 * (ATA_BMISP_DMAERROR	, CLEAR)
> > +	 */
> > +	iowrite16(0, base + BK3710_BMISP);
> 
>     Bits 0-3 cane only be cleared by writing 1, so this write can't clear 

The documentation does say this about bits 1-3, bit 0 is handled in
a different way.

> them, contrary to what the comment says. Might be a material for a follow-up 
> patch tho...

Will fix in the incremental patch in v3.

> [...]
> > +static int __init pata_bk3710_probe(struct platform_device *pdev)
> > +{
> > +	struct clk *clk;
> > +	struct resource *mem;
> > +	struct ata_host *host;
> > +	struct ata_port *ap;
> > +	void __iomem *base;
> > +	unsigned long rate;
> > +	int irq;
> > +
> > +	clk = devm_clk_get(&pdev->dev, NULL);
> > +	if (IS_ERR(clk))
> > +		return -ENODEV;
> > +
> > +	clk_enable(clk);
> > +	rate = clk_get_rate(clk);
> > +	if (!rate)
> > +		return -EINVAL;
> > +
> > +	/* NOTE:  round *down* to meet minimum timings; we count in clocks */
> > +	ideclk_period = 1000000000UL / rate;
> > +
> > +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	if (mem == NULL) {
> > +		pr_err(DRV_NAME ": failed to get memory region resource\n");
> > +		return -ENODEV;
> > +	}
> 
>     NULL check not needed here, devm_ioremap_resource() checks this anyway.

Will be fixed in v3.

> > +
> > +	irq = platform_get_irq(pdev, 0);
> > +	if (irq < 0) {
> > +		pr_err(DRV_NAME ": failed to get IRQ resource\n");
> > +		return irq;
> > +	}
> > +
> > +	base = devm_ioremap_resource(&pdev->dev, mem);
> > +	if (IS_ERR(base))
> > +		return PTR_ERR(base);
> > +
> [...]
> > +/* work with hotplug and coldplug */
> > +MODULE_ALIAS("platform:palm_bk3710");
> > +
> > +static struct platform_driver pata_bk3710_driver = {
> > +	.driver = {
> > +		.name = "palm_bk3710",
> 
>     Not DRV_NAME?

DRV_NAME is "pata_bk3710" and the platform driver name needs to
match the old driver name for compatibility reasons (supporting
both drivers by the arch specific code).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
diff mbox

Patch

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 70b57d2..38fa4ac 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -510,6 +510,15 @@  config PATA_BF54X
 
 	  If unsure, say N.
 
+config PATA_BK3710
+	tristate "Palmchip BK3710 PATA support"
+	depends on ARCH_DAVINCI
+	help
+	  This option enables support for the integrated IDE controller on
+	  the TI DaVinci SoC.
+
+	  If unsure, say N.
+
 config PATA_CMD64X
 	tristate "CMD64x PATA support"
 	depends on PCI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 89a0a19..9438db8 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -50,6 +50,7 @@  obj-$(CONFIG_PATA_ARTOP)	+= pata_artop.o
 obj-$(CONFIG_PATA_ATIIXP)	+= pata_atiixp.o
 obj-$(CONFIG_PATA_ATP867X)	+= pata_atp867x.o
 obj-$(CONFIG_PATA_BF54X)	+= pata_bf54x.o
+obj-$(CONFIG_PATA_BK3710)	+= pata_bk3710.o
 obj-$(CONFIG_PATA_CMD64X)	+= pata_cmd64x.o
 obj-$(CONFIG_PATA_CS5520)	+= pata_cs5520.o
 obj-$(CONFIG_PATA_CS5530)	+= pata_cs5530.o
diff --git a/drivers/ata/pata_bk3710.c b/drivers/ata/pata_bk3710.c
new file mode 100644
index 0000000..6d77217
--- /dev/null
+++ b/drivers/ata/pata_bk3710.c
@@ -0,0 +1,386 @@ 
+/*
+ * Palmchip BK3710 PATA controller driver
+ *
+ * Copyright (c) 2017 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Based on palm_bk3710.c:
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software, Inc., <source@mvista.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/ata.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/libata.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#define DRV_NAME "pata_bk3710"
+
+#define BK3710_TF_OFFSET	0x1F0
+#define BK3710_CTL_OFFSET	0x3F6
+
+#define BK3710_BMISP		0x02
+#define BK3710_IDETIMP		0x40
+#define BK3710_UDMACTL		0x48
+#define BK3710_MISCCTL		0x50
+#define BK3710_REGSTB		0x54
+#define BK3710_REGRCVR		0x58
+#define BK3710_DATSTB		0x5C
+#define BK3710_DATRCVR		0x60
+#define BK3710_DMASTB		0x64
+#define BK3710_DMARCVR		0x68
+#define BK3710_UDMASTB		0x6C
+#define BK3710_UDMATRP		0x70
+#define BK3710_UDMAENV		0x74
+#define BK3710_IORDYTMP		0x78
+
+static struct scsi_host_template pata_bk3710_sht = {
+	ATA_BMDMA_SHT(DRV_NAME),
+};
+
+static unsigned int ideclk_period; /* in nanoseconds */
+
+struct pata_bk3710_udmatiming {
+	unsigned int rptime;	/* tRP -- Ready to pause time (nsec) */
+	unsigned int cycletime;	/* tCYCTYP2/2 -- avg Cycle Time (nsec) */
+				/* tENV is always a minimum of 20 nsec */
+};
+
+static const struct pata_bk3710_udmatiming pata_bk3710_udmatimings[6] = {
+	{ 160, 240 / 2 },	/* UDMA Mode 0 */
+	{ 125, 160 / 2 },	/* UDMA Mode 1 */
+	{ 100, 120 / 2 },	/* UDMA Mode 2 */
+	{ 100,  90 / 2 },	/* UDMA Mode 3 */
+	{ 100,  60 / 2 },	/* UDMA Mode 4 */
+	{  85,  40 / 2 },	/* UDMA Mode 5 */
+};
+
+static void pata_bk3710_setudmamode(void __iomem *base, unsigned int dev,
+				    unsigned int mode)
+{
+	u32 val32;
+	u16 val16;
+	u8 tenv, trp, t0;
+
+	/* DMA Data Setup */
+	t0 = DIV_ROUND_UP(pata_bk3710_udmatimings[mode].cycletime,
+			  ideclk_period) - 1;
+	tenv = DIV_ROUND_UP(20, ideclk_period) - 1;
+	trp = DIV_ROUND_UP(pata_bk3710_udmatimings[mode].rptime,
+			   ideclk_period) - 1;
+
+	/* udmastb Ultra DMA Access Strobe Width */
+	val32 = ioread32(base + BK3710_UDMASTB) & (0xFF << (dev ? 0 : 8));
+	val32 |= t0 << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_UDMASTB);
+
+	/* udmatrp Ultra DMA Ready to Pause Time */
+	val32 = ioread32(base + BK3710_UDMATRP) & (0xFF << (dev ? 0 : 8));
+	val32 |= trp << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_UDMATRP);
+
+	/* udmaenv Ultra DMA envelop Time */
+	val32 = ioread32(base + BK3710_UDMAENV) & (0xFF << (dev ? 0 : 8));
+	val32 |= tenv << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_UDMAENV);
+
+	/* Enable UDMA for Device */
+	val16 = ioread16(base + BK3710_UDMACTL) | (1 << dev);
+	iowrite16(val16, base + BK3710_UDMACTL);
+}
+
+static void pata_bk3710_setmwdmamode(void __iomem *base, unsigned int dev,
+				   unsigned short min_cycle,
+				   unsigned int mode)
+{
+	const struct ata_timing *t;
+	int cycletime;
+	u32 val32;
+	u16 val16;
+	u8 td, tkw, t0;
+
+	t = ata_timing_find_mode(mode);
+	cycletime = max_t(int, t->cycle, min_cycle);
+
+	/* DMA Data Setup */
+	t0 = DIV_ROUND_UP(cycletime, ideclk_period);
+	td = DIV_ROUND_UP(t->active, ideclk_period);
+	tkw = t0 - td - 1;
+	td--;
+
+	val32 = ioread32(base + BK3710_DMASTB) & (0xFF << (dev ? 0 : 8));
+	val32 |= td << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_DMASTB);
+
+	val32 = ioread32(base + BK3710_DMARCVR) & (0xFF << (dev ? 0 : 8));
+	val32 |= tkw << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_DMARCVR);
+
+	/* Disable UDMA for Device */
+	val16 = ioread16(base + BK3710_UDMACTL) & ~(1 << dev);
+	iowrite16(val16, base + BK3710_UDMACTL);
+}
+
+static void pata_bk3710_set_dmamode(struct ata_port *ap,
+				    struct ata_device *adev)
+{
+	void __iomem *base = (void __iomem *)ap->ioaddr.bmdma_addr;
+	int is_slave = adev->devno;
+	const u8 xferspeed = adev->dma_mode;
+
+	if (xferspeed >= XFER_UDMA_0)
+		pata_bk3710_setudmamode(base, is_slave,
+					xferspeed - XFER_UDMA_0);
+	else
+		pata_bk3710_setmwdmamode(base, is_slave,
+				       adev->id[ATA_ID_EIDE_DMA_MIN],
+				       xferspeed);
+}
+
+static void pata_bk3710_setpiomode(void __iomem *base, struct ata_device *pair,
+				   unsigned int dev, unsigned int cycletime,
+				   unsigned int mode)
+{
+	const struct ata_timing *t;
+	u32 val32;
+	u8 t2, t2i, t0;
+
+	t = ata_timing_find_mode(XFER_PIO_0 + mode);
+
+	/* PIO Data Setup */
+	t0 = DIV_ROUND_UP(cycletime, ideclk_period);
+	t2 = DIV_ROUND_UP(t->active, ideclk_period);
+
+	t2i = t0 - t2 - 1;
+	t2--;
+
+	val32 = ioread32(base + BK3710_DATSTB) & (0xFF << (dev ? 0 : 8));
+	val32 |= t2 << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_DATSTB);
+
+	val32 = ioread32(base + BK3710_DATRCVR) & (0xFF << (dev ? 0 : 8));
+	val32 |= t2i << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_DATRCVR);
+
+	/* FIXME: this is broken also in the old driver */
+	if (pair) {
+		u8 mode2 = pair->pio_mode - XFER_PIO_0;
+
+		if (mode2 < mode)
+			mode = mode2;
+	}
+
+	/* TASKFILE Setup */
+	t0 = DIV_ROUND_UP(t->cyc8b, ideclk_period);
+	t2 = DIV_ROUND_UP(t->act8b, ideclk_period);
+
+	t2i = t0 - t2 - 1;
+	t2--;
+
+	val32 = ioread32(base + BK3710_REGSTB) & (0xFF << (dev ? 0 : 8));
+	val32 |= t2 << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_REGSTB);
+
+	val32 = ioread32(base + BK3710_REGRCVR) & (0xFF << (dev ? 0 : 8));
+	val32 |= t2i << (dev ? 8 : 0);
+	iowrite32(val32, base + BK3710_REGRCVR);
+}
+
+static void pata_bk3710_set_piomode(struct ata_port *ap,
+				    struct ata_device *adev)
+{
+	void __iomem *base = (void __iomem *)ap->ioaddr.bmdma_addr;
+	struct ata_device *pair = ata_dev_pair(adev);
+	const struct ata_timing *t = ata_timing_find_mode(adev->pio_mode);
+	const u16 *id = adev->id;
+	unsigned int cycle_time = 0;
+	int is_slave = adev->devno;
+	const u8 pio = adev->pio_mode - XFER_PIO_0;
+
+	if (id[ATA_ID_FIELD_VALID] & 2) {
+		if (ata_id_has_iordy(id))
+			cycle_time = id[ATA_ID_EIDE_PIO_IORDY];
+		else
+			cycle_time = id[ATA_ID_EIDE_PIO];
+
+		/* conservative "downgrade" for all pre-ATA2 drives */
+		if (pio < 3 && cycle_time < t->cycle)
+			cycle_time = 0; /* use standard timing */
+	}
+
+	if (!cycle_time)
+		cycle_time = t->cycle;
+
+	pata_bk3710_setpiomode(base, pair, is_slave, cycle_time, pio);
+}
+
+static void pata_bk3710_chipinit(void __iomem *base)
+{
+	/*
+	 * REVISIT:  the ATA reset signal needs to be managed through a
+	 * GPIO, which means it should come from platform_data.  Until
+	 * we get and use such information, we have to trust that things
+	 * have been reset before we get here.
+	 */
+
+	/*
+	 * Program the IDETIMP Register Value based on the following assumptions
+	 *
+	 * (ATA_IDETIMP_IDEEN		, ENABLE ) |
+	 * (ATA_IDETIMP_PREPOST1	, DISABLE) |
+	 * (ATA_IDETIMP_PREPOST0	, DISABLE) |
+	 *
+	 * DM6446 silicon rev 2.1 and earlier have no observed net benefit
+	 * from enabling prefetch/postwrite.
+	 */
+	iowrite16(BIT(15), base + BK3710_IDETIMP);
+
+	/*
+	 * UDMACTL Ultra-ATA DMA Control
+	 * (ATA_UDMACTL_UDMAP1	, 0 ) |
+	 * (ATA_UDMACTL_UDMAP0	, 0 )
+	 *
+	 */
+	iowrite16(0, base + BK3710_UDMACTL);
+
+	/*
+	 * MISCCTL Miscellaneous Conrol Register
+	 * (ATA_MISCCTL_HWNHLD1P	, 1 cycle)
+	 * (ATA_MISCCTL_HWNHLD0P	, 1 cycle)
+	 * (ATA_MISCCTL_TIMORIDE	, 1)
+	 */
+	iowrite32(0x001, base + BK3710_MISCCTL);
+
+	/*
+	 * IORDYTMP IORDY Timer for Primary Register
+	 * (ATA_IORDYTMP_IORDYTMP     , 0xffff  )
+	 */
+	iowrite32(0xFFFF, base + BK3710_IORDYTMP);
+
+	/*
+	 * Configure BMISP Register
+	 * (ATA_BMISP_DMAEN1	, DISABLE )	|
+	 * (ATA_BMISP_DMAEN0	, DISABLE )	|
+	 * (ATA_BMISP_IORDYINT	, CLEAR)	|
+	 * (ATA_BMISP_INTRSTAT	, CLEAR)	|
+	 * (ATA_BMISP_DMAERROR	, CLEAR)
+	 */
+	iowrite16(0, base + BK3710_BMISP);
+
+	pata_bk3710_setpiomode(base, NULL, 0, 600, 0);
+	pata_bk3710_setpiomode(base, NULL, 1, 600, 0);
+}
+
+static struct ata_port_operations pata_bk3710_ports_ops = {
+	.inherits		= &ata_bmdma_port_ops,
+	.cable_detect		= ata_cable_80wire,
+
+	.set_piomode		= pata_bk3710_set_piomode,
+	.set_dmamode		= pata_bk3710_set_dmamode,
+};
+
+static int __init pata_bk3710_probe(struct platform_device *pdev)
+{
+	struct clk *clk;
+	struct resource *mem;
+	struct ata_host *host;
+	struct ata_port *ap;
+	void __iomem *base;
+	unsigned long rate;
+	int irq;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk))
+		return -ENODEV;
+
+	clk_enable(clk);
+	rate = clk_get_rate(clk);
+	if (!rate)
+		return -EINVAL;
+
+	/* NOTE:  round *down* to meet minimum timings; we count in clocks */
+	ideclk_period = 1000000000UL / rate;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (mem == NULL) {
+		pr_err(DRV_NAME ": failed to get memory region resource\n");
+		return -ENODEV;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		pr_err(DRV_NAME ": failed to get IRQ resource\n");
+		return irq;
+	}
+
+	base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	/* configure the Palmchip controller */
+	pata_bk3710_chipinit(base);
+
+	/* allocate host */
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host)
+		return -ENOMEM;
+	ap = host->ports[0];
+
+	ap->ops = &pata_bk3710_ports_ops;
+	ap->pio_mask = ATA_PIO4;
+	ap->mwdma_mask = ATA_MWDMA2;
+	ap->udma_mask = rate < 100000000 ? ATA_UDMA4 : ATA_UDMA5;
+	ap->flags |= ATA_FLAG_SLAVE_POSS;
+
+	ap->ioaddr.data_addr		= base + BK3710_TF_OFFSET;
+	ap->ioaddr.error_addr		= base + BK3710_TF_OFFSET + 1;
+	ap->ioaddr.feature_addr		= base + BK3710_TF_OFFSET + 1;
+	ap->ioaddr.nsect_addr		= base + BK3710_TF_OFFSET + 2;
+	ap->ioaddr.lbal_addr		= base + BK3710_TF_OFFSET + 3;
+	ap->ioaddr.lbam_addr		= base + BK3710_TF_OFFSET + 4;
+	ap->ioaddr.lbah_addr		= base + BK3710_TF_OFFSET + 5;
+	ap->ioaddr.device_addr		= base + BK3710_TF_OFFSET + 6;
+	ap->ioaddr.status_addr		= base + BK3710_TF_OFFSET + 7;
+	ap->ioaddr.command_addr		= base + BK3710_TF_OFFSET + 7;
+
+	ap->ioaddr.altstatus_addr	= base + BK3710_CTL_OFFSET;
+	ap->ioaddr.ctl_addr		= base + BK3710_CTL_OFFSET;
+
+	ap->ioaddr.bmdma_addr		= base;
+
+	ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx",
+		      (unsigned long)base + BK3710_TF_OFFSET,
+		      (unsigned long)base + BK3710_CTL_OFFSET);
+
+	/* activate */
+	return ata_host_activate(host, irq, ata_sff_interrupt, 0,
+				 &pata_bk3710_sht);
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:palm_bk3710");
+
+static struct platform_driver pata_bk3710_driver = {
+	.driver = {
+		.name = "palm_bk3710",
+	},
+};
+
+static int __init pata_bk3710_init(void)
+{
+	return platform_driver_probe(&pata_bk3710_driver, pata_bk3710_probe);
+}
+
+module_init(pata_bk3710_init);
+MODULE_LICENSE("GPL");