Re: [PATCH v2 1/2] ata: ahci_platform: Manage SATA PHY

From: Roger Quadros
Date: Fri Oct 18 2013 - 03:31:15 EST


On 10/17/2013 04:57 PM, Bartlomiej Zolnierkiewicz wrote:
>
> Hi,
>
> On Wednesday, October 16, 2013 02:42:52 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>
>> ---
>> .../devicetree/bindings/ata/ahci-platform.txt | 3 +-
>> drivers/ata/ahci.h | 2 ++
>> drivers/ata/ahci_platform.c | 29 +++++++++++++++++++-
>> 3 files changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
>> index 89de156..c8a6cea 100644
>> --- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
>> +++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
>> @@ -4,7 +4,8 @@ SATA nodes are defined to describe on-chip Serial ATA controllers.
>> Each SATA controller should have its own node.
>>
>> Required properties:
>> -- compatible : compatible list, contains "snps,spear-ahci"
>> +- compatible : compatible list, contains "snps,spear-ahci",
>> + snps,exynos5440-ahci or "snps,dwc-ahci"
>
> minor nit:
> s/snps,exynos5440-ahci/"snps,exynos5440-ahci"/

OK.
>
>> - interrupts : <interrupt mapping for SATA IRQ>
>> - reg : <registers mapping>
>>
>> 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>
>>
>> /* Enclosure Management Control */
>> #define EM_CTRL_MSG_TYPE 0x000f0000
>> @@ -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 */
>
> minor nit:
> s/If platforms use phy/If platform uses PHY/

Right.

>
>> void *plat_data; /* Other platform data */
>> };
>>
>> diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
>> index 2daaee0..5a0f1418 100644
>> --- a/drivers/ata/ahci_platform.c
>> +++ b/drivers/ata/ahci_platform.c
>> @@ -141,6 +141,21 @@ static int ahci_probe(struct platform_device *pdev)
>> }
>> }
>>
>> + hpriv->phy = devm_phy_get(dev, "sata-phy");
>> + if (IS_ERR(hpriv->phy)) {
>> + dev_dbg(dev, "can't get sata-phy\n");
>> + /* return only if -EPROBE_DEFER */
>> + if (PTR_ERR(hpriv->phy) == -EPROBE_DEFER) {
>> + rc = -EPROBE_DEFER;
>> + goto disable_unprepare_clk;
>> + }
>> + }
>> +
>> + if (!IS_ERR(hpriv->phy)) {
>> + phy_init(hpriv->phy);
>> + phy_power_on(hpriv->phy);
>> + }
>> +
>> /*
>> * Some platforms might need to prepare for mmio region access,
>> * which could be done in the following init call. So, the mmio
>> @@ -150,7 +165,7 @@ static int ahci_probe(struct platform_device *pdev)
>> 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,
>> @@ -220,6 +235,12 @@ static int ahci_probe(struct platform_device *pdev)
>> pdata_exit:
>> if (pdata && pdata->exit)
>> pdata->exit(dev);
>> +disable_phy:
>> + if (!IS_ERR(hpriv->phy)) {
>> + phy_power_off(hpriv->phy);
>> + phy_exit(hpriv->phy);
>> + }
>> +
>> disable_unprepare_clk:
>> if (!IS_ERR(hpriv->clk))
>> clk_disable_unprepare(hpriv->clk);
>> @@ -238,6 +259,11 @@ static void ahci_host_stop(struct ata_host *host)
>> if (pdata && pdata->exit)
>> pdata->exit(dev);
>>
>> + if (!IS_ERR(hpriv->phy)) {
>> + phy_power_off(hpriv->phy);
>> + phy_exit(hpriv->phy);
>> + }
>> +
>> if (!IS_ERR(hpriv->clk)) {
>> clk_disable_unprepare(hpriv->clk);
>> clk_put(hpriv->clk);
>> @@ -328,6 +354,7 @@ static SIMPLE_DEV_PM_OPS(ahci_pm_ops, ahci_suspend, ahci_resume);
>
> Shouldn't phy_power_off/on also be used in ahci_suspend() and ahci_resume()?

I think so. Maybe even phy_exit and phy_init?

>
>> static const struct of_device_id ahci_of_match[] = {
>> { .compatible = "snps,spear-ahci", },
>> { .compatible = "snps,exynos5440-ahci", },
>> + { .compatible = "snps,dwc-ahci", },
>
> This change together with ahci-platform.txt one should be in a separate patch.

Agreed.

>
>> {},
>> };
>> MODULE_DEVICE_TABLE(of, ahci_of_match);

cheers,
-roger
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