Subject: [PATCH] add PATA host controller support for Cirrus Logic's EP93xx CPUs

From: [email-masked] (Ryan Mallon)
Date: Wed, 02 Dec 2009 13:53:53 +1300

Bartlomiej Zolnierkiewicz wrote:
> Based on the older IDE host driver by Joao Ramos and review comments
> for it from Sergei Shtylyov.  Not yet tested with the real hardware.
>

Hi Bartlomiej,

I have got as far as patching this into my kernel and doing a build test
(still need to find a hard-disk to test). I got some build errors, see
below:

> +static void pata_ep93xx_set_piomode(struct ata_port *ap,
> +				    struct ata_device *adev)
> +{
> +	void __iomem *base = ap->host->private_data;
> +	struct ata_device *pair = ata_dev_pair(adev);
> +	const struct ata_timing *t = ata_timing_find_mode(adev->pio_mode);
> +	const struct ata_timing *cmd_t = t;
> +	u32 reg = IDECFG_IDEEN | IDECFG_PIO;
> +	u8 pio = adev->pio_mode - XFER_PIO_0;
> +
> +	if (pair && pair->pio_mode < adev->pio_mode)
> +		cmd_t = ata_timing_find_mode(pair->pio_mode);
> +
> +	/*
> +	 * store the adequate PIO mode timings, to be used later
> +	 * by pata_ep93xx_{read,write}
> +	 */
> +	adev->private_data = (void *)t;
> +	ap->private_data = (void *)cmd_t;

struct ata_device has no member called private_data. Do we need to store
both t and cmd_t, or can we just store cmd_t in ap->private_data?

If we need both, can we have something like this (not sure if the member
names are sensible):

	struct ep93xx_ata_timing {
		struct ata_timing *dev_timing;
		struct ata_timing *pair_timing;
	};

and store that struct in ap?

> +unsigned int pata_ep93xx_data_xfer(struct ata_device *adev, unsigned char *buf,
> +				   unsigned int buflen, int rw)
> +{
> +	struct ata_port *ap = adev->link->ap;
> +	void __iomem *base = ap->host->private_data;
> +	void *data_addr = ap->ioaddr.data_addr;
> +	u16 *data = (u16 *)buf;
> +	struct ata_timing *t = adev->private_data;

This is the only place that uses the ata_timing structure stored in
adev->private_data, can this be changed to:

	struct ata_timing *t = ap->private_data;

~Ryan

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