ata: ahci-dwc: Add platform-specific quirks support

Some DWC AHCI SATA IP-core derivatives require to perform small platform
or IP-core specific setups. They are too small to be placed in a dedicated
driver. It's just much easier to have a set of quirks for them right in
the DWC AHCI driver code. Since we are about to add such platform support,
as a pre-requisite we introduce a platform-data based DWC AHCI quirks API.
The platform data can be used to define the flags passed to the
ahci_platform_get_resources() method, additional AHCI host-flags and a set
of callbacks to initialize, re-initialize and clear the platform settings.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

drivers/ata/ahci_dwc.c

@@ -90,7 +90,16 @@
 #define AHCI_DWC_PORT_PHYCR		0x74
 #define AHCI_DWC_PORT_PHYSR		0x78
 
+struct ahci_dwc_plat_data {
+	unsigned int pflags;
+	unsigned int hflags;
+	int (*init)(struct ahci_host_priv *hpriv);
+	int (*reinit)(struct ahci_host_priv *hpriv);
+	void (*clear)(struct ahci_host_priv *hpriv);
+};
+
 struct ahci_dwc_host_priv {
+	const struct ahci_dwc_plat_data *pdata;
 	struct platform_device *pdev;
 
 	u32 timv;
@@ -107,11 +116,15 @@ static struct ahci_host_priv *ahci_dwc_get_resources(struct platform_device *pde
 		return ERR_PTR(-ENOMEM);
 
 	dpriv->pdev = pdev;
+	dpriv->pdata = device_get_match_data(&pdev->dev);
+	if (!dpriv->pdata)
+		return ERR_PTR(-EINVAL);
 
-	hpriv = ahci_platform_get_resources(pdev, AHCI_PLATFORM_GET_RESETS);
+	hpriv = ahci_platform_get_resources(pdev, dpriv->pdata->pflags);
 	if (IS_ERR(hpriv))
 		return hpriv;
 
+	hpriv->flags |= dpriv->pdata->hflags;
 	hpriv->plat_data = (void *)dpriv;
 
 	return hpriv;
@@ -242,22 +255,33 @@ static int ahci_dwc_init_dmacr(struct ahci_host_priv *hpriv)
 
 static int ahci_dwc_init_host(struct ahci_host_priv *hpriv)
 {
+	struct ahci_dwc_host_priv *dpriv = hpriv->plat_data;
 	int rc;
 
 	rc = ahci_platform_enable_resources(hpriv);
 	if (rc)
 		return rc;
 
+	if (dpriv->pdata->init) {
+		rc = dpriv->pdata->init(hpriv);
+		if (rc)
+			goto err_disable_resources;
+	}
+
 	ahci_dwc_check_cap(hpriv);
 
 	ahci_dwc_init_timer(hpriv);
 
 	rc = ahci_dwc_init_dmacr(hpriv);
 	if (rc)
-		goto err_disable_resources;
+		goto err_clear_platform;
 
 	return 0;
 
+err_clear_platform:
+	if (dpriv->pdata->clear)
+		dpriv->pdata->clear(hpriv);
+
 err_disable_resources:
 	ahci_platform_disable_resources(hpriv);
 
@@ -275,6 +299,12 @@ static int ahci_dwc_reinit_host(struct ahci_host_priv *hpriv)
 	if (rc)
 		return rc;
 
+	if (dpriv->pdata->reinit) {
+		rc = dpriv->pdata->reinit(hpriv);
+		if (rc)
+			goto err_disable_resources;
+	}
+
 	writel(dpriv->timv, hpriv->mmio + AHCI_DWC_HOST_TIMER1MS);
 
 	for_each_set_bit(i, &port_map, AHCI_MAX_PORTS) {
@@ -283,10 +313,20 @@ static int ahci_dwc_reinit_host(struct ahci_host_priv *hpriv)
 	}
 
 	return 0;
+
+err_disable_resources:
+	ahci_platform_disable_resources(hpriv);
+
+	return rc;
 }
 
 static void ahci_dwc_clear_host(struct ahci_host_priv *hpriv)
 {
+	struct ahci_dwc_host_priv *dpriv = hpriv->plat_data;
+
+	if (dpriv->pdata->clear)
+		dpriv->pdata->clear(hpriv);
+
 	ahci_platform_disable_resources(hpriv);
 }
 
@@ -370,9 +410,13 @@ static int ahci_dwc_resume(struct device *dev)
 static DEFINE_SIMPLE_DEV_PM_OPS(ahci_dwc_pm_ops, ahci_dwc_suspend,
 				ahci_dwc_resume);
 
+static struct ahci_dwc_plat_data ahci_dwc_plat = {
+	.pflags = AHCI_PLATFORM_GET_RESETS,
+};
+
 static const struct of_device_id ahci_dwc_of_match[] = {
-	{ .compatible = "snps,dwc-ahci", },
-	{ .compatible = "snps,spear-ahci", },
+	{ .compatible = "snps,dwc-ahci", &ahci_dwc_plat },
+	{ .compatible = "snps,spear-ahci", &ahci_dwc_plat },
 	{},
 };
 MODULE_DEVICE_TABLE(of, ahci_dwc_of_match);