libata: pata_samsung_cf: Add Samsung PATA controller driver

From: Abhilash Kesavan <[email protected]>

Adds support for the Samsung PATA controller. This driver is based on the Libata subsystem and references the earlier patches sent for IDE

Signed-off-by Abhilash Kesavan <[email protected]>

Signed-off-by Kukjin Kim <[email protected]>

---

Changes since v3:

Addressed comments from

Sergei Shtylyov:
- Removed filename in header
- Used ata_timing_compute for obtaining timing parameters
- Removed valid PIO mode check
- Added softreset method and associated functions
- Used devm_request_mem_region function as had used devm_ioremap earlier
- Removed kree and release_mem_region calls because of managed kzalloc and request_mem_region fns being used
- Added return in clk_get function
- Added missing clk_put
- Corrected indentation issue

Ben Dooks:
- Added missing 'void __iomem' parameters
- Added check for trailing bytes in data_xfer function
- Removed assignment in data_xfer function
- Coding changes - e.g. in pata_s3c_enable, pata_s3c_dev_select, wait_for_host_ready
- Removed host checks in suspend/resume functions

 drivers/ata/Kconfig           |    9 +
 drivers/ata/Makefile          |    1 +
 drivers/ata/pata_samsung_cf.c |  735
+++++++++++++++++++++++++++++++++++++++++
 3 files changed, 745 insertions(+), 0 deletions(-)
 create mode 100644 drivers/ata/pata_samsung_cf.c

From: Abhilash Kesavan<[email protected]>

Adds support for the Samsung PATA controller. This driver is based on the Libata subsystem and references the earlier patches sent for IDE subsystem.

Signed-off-by Abhilash Kesavan<[email protected]>

Signed-off-by Kukjin Kim<[email protected]>

Quoted 3 lines · Kukjin Kim

From: Abhilash Kesavan<[email protected]>

Adds support for the Samsung PATA controller. This driver is based on

Quoted 1 line

Libata subsystem and references the earlier patches sent for IDE

Quoted 3 lines

Signed-off-by Abhilash Kesavan<[email protected]>

Signed-off-by Kukjin Kim<[email protected]>

Acked-by Jeff Garzik <[email protected]>

Send it through the appropriate subsystem tree for this platform...

Quoted 4 lines · Jeff Garzik

Quoted 3 lines · Kukjin Kim

From: Abhilash Kesavan<[email protected]>

Adds support for the Samsung PATA controller. This driver is based on

the

Quoted 1 line

Quoted 1 line

Libata subsystem and references the earlier patches sent for IDE

subsystem.

Quoted 6 lines

Quoted 2 lines

Signed-off-by Abhilash Kesavan<[email protected]>

Signed-off-by Kukjin Kim<[email protected]>

Acked-by Jeff Garzik <[email protected]>

Send it through the appropriate subsystem tree for this platform...

Hi,

You mean in my case, appropriate subsystem tree is ARM tree. But I think, as Ben commented, it's better drivers go to upstream via the driver's tree.
And of course, I read your comments about this like below... 'platform drivers do not build and/or work without additional platform glue...'

Hmm.
I'm not sure which way is better...

Russell,

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <[email protected]>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd.

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Dne Pá 25. června 2010 05:38:19 Kukjin Kim napsal(a):

Quoted 28 lines

Quoted 4 lines · Jeff Garzik

Quoted 3 lines · Kukjin Kim

From: Abhilash Kesavan<[email protected]>

Adds support for the Samsung PATA controller. This driver is based on

the

Quoted 1 line

Quoted 1 line

Libata subsystem and references the earlier patches sent for IDE

subsystem.

Quoted 6 lines

Quoted 2 lines

Signed-off-by Abhilash Kesavan<[email protected]>

Signed-off-by Kukjin Kim<[email protected]>

Acked-by Jeff Garzik <[email protected]>

Send it through the appropriate subsystem tree for this platform...

Hi,

You mean in my case, appropriate subsystem tree is ARM tree. But I think, as Ben commented, it's better drivers go to upstream via the driver's tree.
And of course, I read your comments about this like below... 'platform drivers do not build and/or work without additional platform glue...'

Quoted 2 lines

Hmm.
I'm not sure which way is better...

I pushed pata_pxa through Eric as well ... go for the linux-arm tree.

Cheers

Quoted 7 lines

Russell,

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

Russell,

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

Quoted 3 lines

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

If Jeff is happy, then I'm happy. However, shouldn't it also have Ben's ack?

Hello.

Russell King - ARM Linux wrote:

Quoted 6 lines

Quoted 3 lines

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

If Jeff is happy, then I'm happy. However, shouldn't it also have Ben's ack?

I for one still have comments to be addressed, will post in a jiffy...

Quoted 5 lines · Kukjin Kim

Russell,

How do you think?
May I send this to your patch tracking system?
Or...how should I handle this?

If Jeff is happy, then I'm happy. However, shouldn't it also have Ben's ack?

From: Abhilash Kesavan <[email protected]>

Adds support for the Samsung PATA controller. This driver is based on the Libata subsystem and references the earlier patches sent for IDE subsystem.

Signed-off-by Abhilash Kesavan <[email protected]>

Signed-off-by Kukjin Kim <[email protected]>

drivers/ata/pata_samsung_cf.c new file +0 -0

new file mode 100644
index 0000000..aeb2825
@@ -0,0 +1,735 @@

drivers/ata/pata_samsung_cf.c new file +20 -0

+/*
+ * pata_s3c_data_xfer - Transfer data by PIO
+ */
+unsigned int pata_s3c_data_xfer(struct ata_device *dev, unsigned char *buf,
+				unsigned int buflen, int rw)
+{
+	struct ata_port *ap = dev->link->ap;
+	struct s3c_ide_info *info = ap->host->private_data;
+	void __iomem *data_addr = ap->ioaddr.data_addr;
+	unsigned int words = buflen >> 1, i;
+	u16 *data_ptr = (u16 *)buf;
+
+	/* Requires wait same as in ata_inb/ata_outb */
+	if (rw == READ)
+		for (i = 0; i < words; i++, data_ptr++) {
+			wait_for_host_ready(info);
+			(void) readw(data_addr);
+			wait_for_host_ready(info);
+			*data_ptr = readw(info->ide_addr
+					+ S3C_ATA_PIO_RDATA);

drivers/ata/pata_samsung_cf.c new file +4 -0

+	}
+
+	return words << 1;
+}

drivers/ata/pata_samsung_cf.c new file +16 -0

+/*
+ * pata_s3c_wait_after_reset - wait for devices to become ready after reset
+ */
+static int pata_s3c_wait_after_reset(struct ata_link *link,
+		unsigned int devmask, unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_ioports *ioaddr = &ap->ioaddr;
+	unsigned int dev0 = devmask & (1 << 0);
+	unsigned int dev1 = devmask & (1 << 1);
+	int rc, ret = 0;
+
+	msleep(ATA_WAIT_AFTER_RESET);
+
+	/* always check readiness of the master device */
+	rc = ata_sff_wait_ready(link, deadline);

drivers/ata/pata_samsung_cf.c new file +9 -0

+
+		for (i = 0; i < 2; i++) {
+			u8 nsect, lbal;
+
+			nsect = ata_inb(ap->host, ioaddr->nsect_addr);
+			lbal = ata_inb(ap->host, ioaddr->lbal_addr);
+			if ((nsect == 1) && (lbal == 1))
+				break;
+			msleep(50);	/* give drive a breather */

drivers/ata/pata_samsung_cf.c new file +5 -0

+static void pata_s3c_hwinit(struct s3c_ide_info *info,
+				struct s3c_ide_platdata *pdata)
+{
+	switch (info->cpu_type) {
+	case TYPE_S3C64XX:

+static int __devinit pata_s3c_probe(struct platform_device *pdev)

drivers/ata/pata_samsung_cf.c new file +11 -0

+{
+	struct s3c_ide_platdata *pdata = pdev->dev.platform_data;
+	struct device *dev = &pdev->dev;
+	struct s3c_ide_info *info;
+	struct resource *res;
+	struct ata_port *ap;
+	struct ata_host *host;
+	enum s3c_cpu_type cpu_type;
+	int ret;
+
+	cpu_type = platform_get_device_id(pdev)->driver_data;

drivers/ata/pata_samsung_cf.c new file +4 -0

+		ap->flags |= ATA_FLAG_PIO_POLLING;
+		ata_port_desc(ap, "no IRQ, using PIO polling\n");
+	}
+

Hello.

Quoted 3 lines · Kukjin Kim

From: Abhilash Kesavan <[email protected]>

Adds support for the Samsung PATA controller. This driver is based on

Quoted 1 line

Libata subsystem and references the earlier patches sent for IDE

Quoted 3 lines

Signed-off-by Abhilash Kesavan <[email protected]>

Signed-off-by Kukjin Kim <[email protected]>

[...]

Review

Quoted 1 line

(quoted diff) +0 -0

Quoted 5 lines

new file mode 100644
index 0000000..aeb2825

drivers/ata/pata_samsung_cf.c new file +0 -0

@@ -0,0 +1,735 @@

[...]

drivers/ata/pata_samsung_cf.c

Quoted 2 lines

drivers/ata/pata_samsung_cf.c new file +2 -0

+static unsigned long
+pata_s3c_setup_timing(struct s3c_ide_info *info, const struct

drivers/ata/pata_samsung_cf.c line 80

Quoted 9 lines

drivers/ata/pata_samsung_cf.c new file +9 -0

+{
+	int t1;
+	int t2;
+	int t2i;
+	ulong piotime;
+
+	t1 = ata->setup;
+	t2 = ata->act8b;
+	t2i = ata->rec8b;

Could be initializers...

[...]

drivers/ata/pata_samsung_cf.c

Quoted 4 lines

drivers/ata/pata_samsung_cf.c new file +4 -0

+/*
+ * pata_s3c_data_xfer - Transfer data by PIO
+ */
+unsigned int pata_s3c_data_xfer(struct ata_device *dev, unsigned char

Quoted 20 lines

drivers/ata/pata_samsung_cf.c new file +20 -0

+				unsigned int buflen, int rw)
+{
+	struct ata_port *ap = dev->link->ap;
+	struct s3c_ide_info *info = ap->host->private_data;
+	void __iomem *data_addr = ap->ioaddr.data_addr;
+	unsigned int words = buflen >> 1, i;
+	u16 *data_ptr = (u16 *)buf;
+
+	/* Requires wait same as in ata_inb/ata_outb */
+	if (rw == READ)
+		for (i = 0; i < words; i++, data_ptr++) {
+			wait_for_host_ready(info);
+			(void) readw(data_addr);
+			wait_for_host_ready(info);
+			*data_ptr = readw(info->ide_addr
+					+ S3C_ATA_PIO_RDATA);
+		}
+	else
+		for (i = 0; i < words; i++, data_ptr++) {
+			wait_for_host_ready(info);

drivers/ata/pata_samsung_cf.c line 274

Quoted 6 lines

drivers/ata/pata_samsung_cf.c new file +6 -0

+			writew(*data_ptr, data_addr);
+		}
+
+	if (buflen & 0x01) {
+		dev_err(ap->dev, "unexpected trailing data\n");
+		return -EINVAL;

This method should return number of bytes consumed, never error...

Quoted 4 lines

drivers/ata/pata_samsung_cf.c new file +4 -0

+	}
+
+	return words << 1;
+}

[...]

drivers/ata/pata_samsung_cf.c line 303

Quoted 10 lines

drivers/ata/pata_samsung_cf.c new file +10 -0

+/*
+ * pata_s3c_devchk - PATA device presence detection
+ */
+static unsigned int pata_s3c_devchk(struct ata_port *ap,
+				unsigned int device)
+{
+	struct ata_ioports *ioaddr = &ap->ioaddr;
+	u8 nsect, lbal;
+
+	ap->ops->sff_dev_select(ap, device);

Can call pata_s3c_dev_select() directly...

Quoted 2 lines

+/*
+ * pata_s3c_wait_after_reset - wait for devices to become ready after

Quoted 14 lines

+ */

drivers/ata/pata_samsung_cf.c new file +13 -0

+static int pata_s3c_wait_after_reset(struct ata_link *link,
+		unsigned int devmask, unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	struct ata_ioports *ioaddr = &ap->ioaddr;
+	unsigned int dev0 = devmask & (1 << 0);
+	unsigned int dev1 = devmask & (1 << 1);
+	int rc, ret = 0;
+
+	msleep(ATA_WAIT_AFTER_RESET);
+
+	/* always check readiness of the master device */
+	rc = ata_sff_wait_ready(link, deadline);

drivers/ata/pata_samsung_cf.c line 348

Quoted 10 lines

drivers/ata/pata_samsung_cf.c new file +10 -0

+	if (rc)
+		return rc;
+
+	/* if device 1 was found in ata_devchk, wait for register
+	 * access briefly, then wait for BSY to clear.
+	 */
+	if (dev1) {
+		int i;
+
+		ap->ops->sff_dev_select(ap, 1);

Ditto.

Quoted 14 lines

drivers/ata/pata_samsung_cf.c new file +14 -0

+
+		for (i = 0; i < 2; i++) {
+			u8 nsect, lbal;
+
+			nsect = ata_inb(ap->host, ioaddr->nsect_addr);
+			lbal = ata_inb(ap->host, ioaddr->lbal_addr);
+			if ((nsect == 1) && (lbal == 1))
+				break;
+			msleep(50);	/* give drive a breather */
+		}
+
+		rc = ata_sff_wait_ready(link, deadline);
+		if (rc) {
+			if (rc != -ENODEV)

drivers/ata/pata_samsung_cf.c line 367

Quoted 5 lines

drivers/ata/pata_samsung_cf.c new file +5 -0

+				return rc;
+			ret = rc;
+		}
+	}
+

Should have copied the original commant here, cause I dount that this
drive selection trickery is indeed necessary...

drivers/ata/pata_samsung_cf.c line 372

Quoted 5 lines

drivers/ata/pata_samsung_cf.c new file +5 -0

+	ap->ops->sff_dev_select(ap, 0);
+	if (dev1)
+		ap->ops->sff_dev_select(ap, 1);
+	if (dev0)
+		ap->ops->sff_dev_select(ap, 0);

Ditto.

drivers/ata/pata_samsung_cf.c

Quoted 4 lines

drivers/ata/pata_samsung_cf.c new file +4 -0

+/*
+ * pata_s3c_softreset - reset host port via ATA SRST
+ */
+static int pata_s3c_softreset(struct ata_link *link, unsigned int

drivers/ata/pata_samsung_cf.c line 403

Quoted 4 lines

drivers/ata/pata_samsung_cf.c new file +4 -0

+			 unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;

I don't see where you set this flag, hence the check seems useless.

drivers/ata/pata_samsung_cf.c line 415

Quoted 12 lines

drivers/ata/pata_samsung_cf.c new file +12 -0

+	unsigned int devmask = 0;
+	int rc;
+	u8 err;
+
+	/* determine if device 0/1 are present */
+	if (pata_s3c_devchk(ap, 0))
+		devmask |= (1 << 0);
+	if (slave_possible && pata_s3c_devchk(ap, 1))
+		devmask |= (1 << 1);
+
+	/* select device 0 again */
+	ap->ops->sff_dev_select(ap, 0);

Can call pata_s3c_dev_select() directly...

drivers/ata/pata_samsung_cf.c line 420

Quoted 5 lines

drivers/ata/pata_samsung_cf.c new file +5 -0

+
+	/* issue bus reset */
+	rc = pata_s3c_bus_softreset(ap, devmask, deadline);
+	/* if link is occupied, -ENODEV too is an error */
+	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {

sata_scr_valid() doesn't apply to your PATA driver, no need to call

Quoted 5 lines

drivers/ata/pata_samsung_cf.c new file +5 -0

+static void pata_s3c_hwinit(struct s3c_ide_info *info,
+				struct s3c_ide_platdata *pdata)
+{
+	switch (info->cpu_type) {
+	case TYPE_S3C64XX:

drivers/ata/pata_samsung_cf.c line 499

Quoted 10 lines

drivers/ata/pata_samsung_cf.c new file +10 -0

+		/* Configure as big endian */
+		pata_s3c_cfg_mode(info->sfr_addr);
+		pata_s3c_set_endian(info->ide_addr, 1);
+		pata_s3c_enable(info->ide_addr, true);
+		msleep(100);
+
+		/* Remove IRQ Status */
+		writel(0x1f, info->ide_addr + S3C_ATA_IRQ);
+		writel(0x1b, info->ide_addr + S3C_ATA_IRQ_MSK);
+	break;

Mis-indented: one more tab needed.

drivers/ata/pata_samsung_cf.c line 502

Quoted 3 lines

drivers/ata/pata_samsung_cf.c new file +3 -0

+
+	case TYPE_S5PC100:
+		pata_s3c_cfg_mode(info->sfr_addr);

There should be a comment like /* FALLTHRU */ if *break* is omitted.

drivers/ata/pata_samsung_cf.c line 513

Quoted 10 lines

drivers/ata/pata_samsung_cf.c new file +10 -0

+	case TYPE_S5PV210:
+		/* Configure as little endian */
+		pata_s3c_set_endian(info->ide_addr, 0);
+		pata_s3c_enable(info->ide_addr, true);
+		msleep(100);
+
+		/* Remove IRQ Status */
+		writel(0x3f, info->ide_addr + S3C_ATA_IRQ);
+		writel(0x3f, info->ide_addr + S3C_ATA_IRQ_MSK);
+	break;

Mis-indented.

Quoted 1 line

+static int __devinit pata_s3c_probe(struct platform_device *pdev)

Is this device really hot-pluggable? Shouldn't this be '__init'

Quoted 15 lines

drivers/ata/pata_samsung_cf.c new file +15 -0

+{
+	struct s3c_ide_platdata *pdata = pdev->dev.platform_data;
+	struct device *dev = &pdev->dev;
+	struct s3c_ide_info *info;
+	struct resource *res;
+	struct ata_port *ap;
+	struct ata_host *host;
+	enum s3c_cpu_type cpu_type;
+	int ret;
+
+	cpu_type = platform_get_device_id(pdev)->driver_data;
+
+	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		dev_err(dev, "failed to allocate memory for device data\n");

drivers/ata/pata_samsung_cf.c line 541

Quoted 6 lines

drivers/ata/pata_samsung_cf.c new file +6 -0

+		return -ENOMEM;
+	}
+
+	info->irq = platform_get_irq(pdev, 0);
+	if (info->irq < 0) {
+		dev_err(dev, "could not obtain irq number\n");

You driver permits working without IRQ -- why require an IRQ resource

if there's no IRQ?

[...]

drivers/ata/pata_samsung_cf.c line 602

Quoted 1 line

drivers/ata/pata_samsung_cf.c new file +1 -0

+	if (!info->irq) {

    Should be (info->irq <= 0) instead, I think, with the above check

Quoted 4 lines

drivers/ata/pata_samsung_cf.c new file +4 -0

+		ap->flags |= ATA_FLAG_PIO_POLLING;
+		ata_port_desc(ap, "no IRQ, using PIO polling\n");
+	}
+

[...]

drivers/ata/pata_samsung_cf.c line 707

Quoted 2 lines

drivers/ata/pata_samsung_cf.c new file +2 -0

+static struct platform_driver pata_s3c_driver = {
+	.probe		= pata_s3c_probe,

If this function will be '__init', this needs to be removed.

[...]

drivers/ata/pata_samsung_cf.c line 721

Quoted 3 lines

drivers/ata/pata_samsung_cf.c new file +3 -0

+static int __init pata_s3c_init(void)
+{
+	return platform_driver_register(&pata_s3c_driver);

I'd coinsider platform_driver_probe() -- this device doesn't seem to

hot-pluggable...