Sergei Shtylyov wrote:

Hello.

Hello :-)

Thanks for your review and comments.

Kukjin Kim wrote:

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From: Abhilash Kesavan <redacted>

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

the

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Libata subsystem and references the earlier patches sent for IDE

subsystem.

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Signed-off-by: Abhilash Kesavan <redacted>
Signed-off-by: Kukjin Kim <redacted>

[...]

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diff --git a/drivers/ata/pata_samsung_cf.c

b/drivers/ata/pata_samsung_cf.c

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new file mode 100644
index 0000000..aeb2825

--- /dev/null
+++ b/drivers/ata/pata_samsung_cf.c

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

[...]

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

ata_timing *ata)

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

    Could be initializers...

OK.

[...]

quoted

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

*buf,

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+				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);
+			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...

OK..will remove the invalid return.

quoted

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

[...]

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+/*
+ * 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...

Will replace it throughout the file.

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

reset

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+ */
+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);
+	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.

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

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

Will add comment.

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+	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.

quoted

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

*classes,

quoted

+			 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.

Will remove the checks associated with this flag.

quoted

+	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...

quoted

+
+	/* 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

it.

OK

quoted

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

quoted

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

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

quoted

+	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.

Will correct the indentation and add a fall through comment.

quoted

+static int __devinit pata_s3c_probe(struct platform_device *pdev)

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

instead?

No, it's not..will change to __init.

quoted

+{
+	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");
+		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

even

if there's no IRQ?

Will remove the check as driver can be used in polling mode.

[...]

quoted

+	if (!info->irq) {

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

removed.

OK

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

[...]

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

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

Will remove probe method and used platform_driver_probe().

[...]

quoted

+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

be

hot-pluggable...

Thanks. Will re-submit updated soon.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim [off-list ref], Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.