Re: [RFC PATCH 08/15] ata: ahci_platform: Manage SATA PHY

From: Sergei Shtylyov
Date: Sun Sep 22 2013 - 14:22:41 EST


Hello.

On 09/19/2013 05:05 PM, Roger Quadros wrote:

From: Balaji T K <balajitk@xxxxxx>

Some platforms have a PHY hooked up to the
SATA controller. The PHY needs to be initialized
and powered up for SATA to work. We do that
using the PHY framework.

[Roger Q] Cleaned up.

CC: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Balaji T K <balajitk@xxxxxx>
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
[...]

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 1145637..94484cb 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -37,6 +37,7 @@

#include <linux/clk.h>
#include <linux/libata.h>
+#include <linux/phy/phy.h>

struct phy;

should suffice.

@@ -322,6 +323,7 @@ struct ahci_host_priv {
u32 em_buf_sz; /* EM buffer size in byte */
u32 em_msg_type; /* EM message type */
struct clk *clk; /* Only for platforms supporting clk */
+ struct phy *phy; /* If platforms use phy */
void *plat_data; /* Other platform data */
};

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 2daaee0..f812ffa 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -23,6 +23,7 @@
#include <linux/platform_device.h>
#include <linux/libata.h>
#include <linux/ahci_platform.h>
+#include <linux/phy/phy.h>

Why include it from both ahci.h and here?

#include "ahci.h"

static void ahci_host_stop(struct ata_host *host);
@@ -141,16 +142,32 @@ static int ahci_probe(struct platform_device *pdev)
}
}

+ hpriv->phy = devm_phy_get(dev, "sata-phy");
+ if (IS_ERR(hpriv->phy)) {
+ dev_err(dev, "can't get phy\n");

Don't think it's a good idea to complain about missing PHY when the driver doesn't even use it.

+ /* return only if -EPROBE_DEFER */
+ if (PTR_ERR(hpriv->phy) == -EPROBE_DEFER) {
+ rc = -EPROBE_DEFER;
+ goto disable_unprepare_clk;
+ }
+ }
+
/*
* Some platforms might need to prepare for mmio region access,
* which could be done in the following init call. So, the mmio
* region shouldn't be accessed before init (if provided) has
* returned successfully.
*/
+
+ if (!(IS_ERR(hpriv->phy))) {

() not needed around IS_ERR() invocation.

+ phy_init(hpriv->phy);
+ phy_power_on(hpriv->phy);
+ }
+

I think this is misplaced, i.e. it should precede the comment.

if (pdata && pdata->init) {
rc = pdata->init(dev, hpriv->mmio);
if (rc)
- goto disable_unprepare_clk;
+ goto disable_phy;
}

ahci_save_initial_config(dev, hpriv,
[...]
@@ -328,6 +356,7 @@ static SIMPLE_DEV_PM_OPS(ahci_pm_ops, ahci_suspend, ahci_resume);
static const struct of_device_id ahci_of_match[] = {
{ .compatible = "snps,spear-ahci", },
{ .compatible = "snps,exynos5440-ahci", },
+ { .compatible = "snps,dwc-ahci", },

Looks like the binding documentation is incomplete -- it doesn't list "snps,exynos5440-ahci"...

WBR, Sergei

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