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Subject[PATCH] ata: ahci-platform: add reset control support
Date
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>
---
.../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);

/*
--
2.7.4
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