ahci: implement ata_save/restore_initial_config()

[powerpc.git] / drivers / ata / ahci.c

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index fd27227..c31b663 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -188,8 +188,10 @@ struct ahci_sg {
 };
 
 struct ahci_host_priv {
-       u32                     cap;    /* cache of HOST_CAP register */
-       u32                     port_map; /* cache of HOST_PORTS_IMPL reg */
+       u32                     cap;            /* cap to use */
+       u32                     port_map;       /* port map to use */
+       u32                     saved_cap;      /* saved initial cap */
+       u32                     saved_port_map; /* saved initial port_map */
 };
 
 struct ahci_port_priv {
@@ -477,6 +479,65 @@ static inline void __iomem *ahci_port_base(void __iomem *base,
        return base + 0x100 + (port * 0x80);
 }
 
+/**
+ *     ahci_save_initial_config - Save and fixup initial config values
+ *     @probe_ent: probe_ent of target device
+ *
+ *     Some registers containing configuration info might be setup by
+ *     BIOS and might be cleared on reset.  This function saves the
+ *     initial values of those registers into @hpriv such that they
+ *     can be restored after controller reset.
+ *
+ *     If inconsistent, config values are fixed up by this function.
+ *
+ *     LOCKING:
+ *     None.
+ */
+static void ahci_save_initial_config(struct ata_probe_ent *probe_ent)
+{
+       struct ahci_host_priv *hpriv = probe_ent->private_data;
+       void __iomem *mmio = probe_ent->iomap[AHCI_PCI_BAR];
+       u32 cap, port_map;
+
+       /* Values prefixed with saved_ are written back to host after
+        * reset.  Values without are used for driver operation.
+        */
+       hpriv->saved_cap = cap = readl(mmio + HOST_CAP);
+       hpriv->saved_port_map = port_map = readl(mmio + HOST_PORTS_IMPL);
+
+       /* fixup zero port_map */
+       if (!port_map) {
+               port_map = (1 << ahci_nr_ports(hpriv->cap)) - 1;
+               dev_printk(KERN_WARNING, probe_ent->dev,
+                          "PORTS_IMPL is zero, forcing 0x%x\n", port_map);
+
+               /* write the fixed up value to the PI register */
+               hpriv->saved_port_map = port_map;
+       }
+
+       /* record values to use during operation */
+       hpriv->cap = cap;
+       hpriv->port_map = port_map;
+}
+
+/**
+ *     ahci_restore_initial_config - Restore initial config
+ *     @mmio: MMIO base for the host
+ *     @hpriv: host private data
+ *
+ *     Restore initial config stored by ahci_save_initial_config().
+ *
+ *     LOCKING:
+ *     None.
+ */
+static void ahci_restore_initial_config(void __iomem *mmio,
+                                       struct ahci_host_priv *hpriv)
+{
+       writel(hpriv->saved_cap, mmio + HOST_CAP);
+       writel(hpriv->saved_port_map, mmio + HOST_PORTS_IMPL);
+       (void) readl(mmio + HOST_PORTS_IMPL);   /* flush */
+}
+
 static u32 ahci_scr_read (struct ata_port *ap, unsigned int sc_reg_in)
 {
        unsigned int sc_reg;
@@ -653,12 +714,10 @@ static int ahci_deinit_port(void __iomem *port_mmio, u32 cap, const char **emsg)
        return 0;
 }
 
-static int ahci_reset_controller(void __iomem *mmio, struct pci_dev *pdev)
+static int ahci_reset_controller(void __iomem *mmio, struct pci_dev *pdev,
+                                struct ahci_host_priv *hpriv)
 {
-       u32 cap_save, impl_save, tmp;
-
-       cap_save = readl(mmio + HOST_CAP);
-       impl_save = readl(mmio + HOST_PORTS_IMPL);
+       u32 tmp;
 
        /* global controller reset */
        tmp = readl(mmio + HOST_CTL);
@@ -683,18 +742,8 @@ static int ahci_reset_controller(void __iomem *mmio, struct pci_dev *pdev)
        writel(HOST_AHCI_EN, mmio + HOST_CTL);
        (void) readl(mmio + HOST_CTL);  /* flush */
 
-       /* These write-once registers are normally cleared on reset.
-        * Restore BIOS values... which we HOPE were present before
-        * reset.
-        */
-       if (!impl_save) {
-               impl_save = (1 << ahci_nr_ports(cap_save)) - 1;
-               dev_printk(KERN_WARNING, &pdev->dev,
-                          "PORTS_IMPL is zero, forcing 0x%x\n", impl_save);
-       }
-       writel(cap_save, mmio + HOST_CAP);
-       writel(impl_save, mmio + HOST_PORTS_IMPL);
-       (void) readl(mmio + HOST_PORTS_IMPL);   /* flush */
+       /* some registers might be cleared on reset.  restore initial values */
+       ahci_restore_initial_config(mmio, hpriv);
 
        if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
                u16 tmp16;
@@ -1432,7 +1481,7 @@ static int ahci_pci_device_resume(struct pci_dev *pdev)
                return rc;
 
        if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
-               rc = ahci_reset_controller(mmio, pdev);
+               rc = ahci_reset_controller(mmio, pdev, hpriv);
                if (rc)
                        return rc;
 
@@ -1543,12 +1592,10 @@ static int ahci_host_init(struct ata_probe_ent *probe_ent)
        unsigned int i, cap_n_ports, using_dac;
        int rc;
 
-       rc = ahci_reset_controller(mmio, pdev);
+       rc = ahci_reset_controller(mmio, pdev, hpriv);
        if (rc)
                return rc;
 
-       hpriv->cap = readl(mmio + HOST_CAP);
-       hpriv->port_map = readl(mmio + HOST_PORTS_IMPL);
        cap_n_ports = ahci_nr_ports(hpriv->cap);
 
        VPRINTK("cap 0x%x  port_map 0x%x  n_ports %d\n",
@@ -1739,6 +1786,8 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        probe_ent->private_data = hpriv;
 
        /* initialize adapter */
+       ahci_save_initial_config(probe_ent);
+
        rc = ahci_host_init(probe_ent);
        if (rc)
                return rc;