Re: [PATCH] ata: ahci-platform: add reset control support

Hans de Goede
2018-03-23T08:19:19Z

Hi,

On 23-03-18 02:30, Kunihiko Hayashi wrote:
> Add support to get and control a list of resets for the device
> as optional and shared. These resets must be kept de-asserted until
> the device is enabled.
>
> This is specified as shared because some SoCs like UniPhier series
> have common reset controls with all ahci controller instances.
>
> Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>

Patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans

> ---
> .../devicetree/bindings/ata/ahci-platform.txt | 1 +
> drivers/ata/ahci.h | 1 +
> drivers/ata/libahci_platform.c | 24 +++++++++++++++++++---
> 3 files changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
> index c760ecb..f4006d3 100644
> --- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
> +++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
> @@ -30,6 +30,7 @@ compatible:
> Optional properties:
> - dma-coherent : Present if dma operations are coherent
> - clocks : a list of phandle + clock specifier pairs
> +- resets : a list of phandle + reset specifier pairs
> - target-supply : regulator for SATA target power
> - phys : reference to the SATA PHY node
> - phy-names : must be "sata-phy"
> diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
> index 749fd94..47ec77a2 100644
> --- a/drivers/ata/ahci.h
> +++ b/drivers/ata/ahci.h
> @@ -347,6 +347,7 @@ struct ahci_host_priv {
> u32 em_msg_type; /* EM message type */
> bool got_runtime_pm; /* Did we do pm_runtime_get? */
> struct clk *clks[AHCI_MAX_CLKS]; /* Optional */
> + struct reset_control *rsts; /* Optional */
> struct regulator **target_pwrs; /* Optional */
> /*
> * If platform uses PHYs. There is a 1:1 relation between the port number and
> diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
> index 341d0ef..3130db9 100644
> --- a/drivers/ata/libahci_platform.c
> +++ b/drivers/ata/libahci_platform.c
> @@ -25,6 +25,7 @@
> #include <linux/phy/phy.h>
> #include <linux/pm_runtime.h>
> #include <linux/of_platform.h>
> +#include <linux/reset.h>
> #include "ahci.h"
>
> static void ahci_host_stop(struct ata_host *host);
> @@ -195,7 +196,8 @@ EXPORT_SYMBOL_GPL(ahci_platform_disable_regulators);
> * following order:
> * 1) Regulator
> * 2) Clocks (through ahci_platform_enable_clks)
> - * 3) Phys
> + * 3) Resets
> + * 4) Phys
> *
> * If resource enabling fails at any point the previous enabled resources
> * are disabled in reverse order.
> @@ -215,12 +217,19 @@ int ahci_platform_enable_resources(struct ahci_host_priv *hpriv)
> if (rc)
> goto disable_regulator;
>
> - rc = ahci_platform_enable_phys(hpriv);
> + rc = reset_control_deassert(hpriv->rsts);
> if (rc)
> goto disable_clks;
>
> + rc = ahci_platform_enable_phys(hpriv);
> + if (rc)
> + goto disable_resets;
> +
> return 0;
>
> +disable_resets:
> + reset_control_assert(hpriv->rsts);
> +
> disable_clks:
> ahci_platform_disable_clks(hpriv);
>
> @@ -239,12 +248,15 @@ EXPORT_SYMBOL_GPL(ahci_platform_enable_resources);
> * following order:
> * 1) Phys
> * 2) Clocks (through ahci_platform_disable_clks)
> - * 3) Regulator
> + * 3) Resets
> + * 4) Regulator
> */
> void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
> {
> ahci_platform_disable_phys(hpriv);
>
> + reset_control_assert(hpriv->rsts);
> +
> ahci_platform_disable_clks(hpriv);
>
> ahci_platform_disable_regulators(hpriv);
> @@ -393,6 +405,12 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev)
> hpriv->clks[i] = clk;
> }
>
> + hpriv->rsts = devm_reset_control_array_get_optional_shared(dev);
> + if (IS_ERR(hpriv->rsts)) {
> + rc = PTR_ERR(hpriv->rsts);
> + goto err_out;
> + }
> +
> hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
>
> /*
>