ahci-platform: "Library-ise" ahci_probe functionality

ahci_probe consists of 3 steps:
1) Get resources (get mmio, clks, regulator)
2) Enable resources, handled by ahci_platform_enable_resouces
3) The more or less standard ahci-host controller init sequence

This commit refactors step 1 and 3 into separate functions, so the platform
drivers for AHCI implementations which need a specific order in step 2,
and / or need to do some custom register poking at some time, can re-use
ahci-platform.c code without needing to copy and paste it.

Note that ahci_platform_init_host's prototype takes the 3 non function
members of ahci_platform_data as arguments, the idea is that drivers using
the new exported utility functions will not use ahci_platform_data at all,
and hopefully in the future ahci_platform_data can go away entirely.

tj: Minor comment formatting updates.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

2 files changed, 137 insertions, 65 deletions

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index a32df31013cb..19e9eaafb1f2 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -188,64 +188,60 @@ void ahci_platform_disable_resources(struct ahci_host_priv *hpriv)
 }
 EXPORT_SYMBOL_GPL(ahci_platform_disable_resources);
 
-static void ahci_put_clks(struct ahci_host_priv *hpriv)
+static void ahci_platform_put_resources(struct device *dev, void *res)
 {
+        struct ahci_host_priv *hpriv = res;
         int c;
 
         for (c = 0; c < AHCI_MAX_CLKS && hpriv->clks[c]; c++)
                 clk_put(hpriv->clks[c]);
 }
 
-static int ahci_probe(struct platform_device *pdev)
+/**
+ * ahci_platform_get_resources - Get platform resources
+ * @pdev: platform device to get resources for
+ *
+ * This function allocates an ahci_host_priv struct, and gets the following
+ * resources, storing a reference to them inside the returned struct:
+ *
+ * 1) mmio registers (IORESOURCE_MEM 0, mandatory)
+ * 2) regulator for controlling the targets power (optional)
+ * 3) 0 - AHCI_MAX_CLKS clocks, as specified in the devs devicetree node,
+ *    or for non devicetree enabled platforms a single clock
+ *
+ * RETURNS:
+ * The allocated ahci_host_priv on success, otherwise an ERR_PTR value
+ */
+struct ahci_host_priv *ahci_platform_get_resources(
+        struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
-        struct ahci_platform_data *pdata = dev_get_platdata(dev);
-        const struct platform_device_id *id = platform_get_device_id(pdev);
-        struct ata_port_info pi = ahci_port_info[id ? id->driver_data : 0];
-        const struct ata_port_info *ppi[] = { &pi, NULL };
         struct ahci_host_priv *hpriv;
-        struct ata_host *host;
-        struct resource *mem;
         struct clk *clk;
-        int irq;
-        int n_ports;
-        int i;
-        int rc;
+        int i, rc = -ENOMEM;
 
-        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-        if (!mem) {
-                dev_err(dev, "no mmio space\n");
-                return -EINVAL;
-        }
-
-        irq = platform_get_irq(pdev, 0);
-        if (irq <= 0) {
-                dev_err(dev, "no irq\n");
-                return -EINVAL;
-        }
+        if (!devres_open_group(dev, NULL, GFP_KERNEL))
+                return ERR_PTR(-ENOMEM);
 
-        if (pdata && pdata->ata_port_info)
-                pi = *pdata->ata_port_info;
-
-        hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
-        if (!hpriv) {
-                dev_err(dev, "can't alloc ahci_host_priv\n");
-                return -ENOMEM;
-        }
+        hpriv = devres_alloc(ahci_platform_put_resources, sizeof(*hpriv),
+                             GFP_KERNEL);
+        if (!hpriv)
+                goto err_out;
 
-        hpriv->flags |= (unsigned long)pi.private_data;
+        devres_add(dev, hpriv);
 
-        hpriv->mmio = devm_ioremap(dev, mem->start, resource_size(mem));
+        hpriv->mmio = devm_ioremap_resource(dev,
+                              platform_get_resource(pdev, IORESOURCE_MEM, 0));
         if (!hpriv->mmio) {
-                dev_err(dev, "can't map %pR\n", mem);
-                return -ENOMEM;
+                dev_err(dev, "no mmio space\n");
+                goto err_out;
         }
 
         hpriv->target_pwr = devm_regulator_get_optional(dev, "target");
         if (IS_ERR(hpriv->target_pwr)) {
                 rc = PTR_ERR(hpriv->target_pwr);
                 if (rc == -EPROBE_DEFER)
-                        return -EPROBE_DEFER;
+                        goto err_out;
                 hpriv->target_pwr = NULL;
         }
 
@@ -264,33 +260,59 @@ static int ahci_probe(struct platform_device *pdev)
                 if (IS_ERR(clk)) {
                         rc = PTR_ERR(clk);
                         if (rc == -EPROBE_DEFER)
-                                goto free_clk;
+                                goto err_out;
                         break;
                 }
                 hpriv->clks[i] = clk;
         }
 
-        rc = ahci_platform_enable_resources(hpriv);
-        if (rc)
-                goto free_clk;
+        devres_remove_group(dev, NULL);
+        return hpriv;
 
-        /*
-         * Some platforms might need to prepare for mmio region access,
-         * which could be done in the following init call. So, the mmio
-         * region shouldn't be accessed before init (if provided) has
-         * returned successfully.
-         */
-        if (pdata && pdata->init) {
-                rc = pdata->init(dev, hpriv->mmio);
-                if (rc)
-                        goto disable_resources;
-        }
+err_out:
+        devres_release_group(dev, NULL);
+        return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_get_resources);
+
+/**
+ * ahci_platform_init_host - Bring up an ahci-platform host
+ * @pdev: platform device pointer for the host
+ * @hpriv: ahci-host private data for the host
+ * @pi_template: template for the ata_port_info to use
+ * @force_port_map: param passed to ahci_save_initial_config
+ * @mask_port_map: param passed to ahci_save_initial_config
+ *
+ * This function does all the usual steps needed to bring up an
+ * ahci-platform host, note any necessary resources (ie clks, phy, etc.)
+ * must be initialized / enabled before calling this.
+ *
+ * RETURNS:
+ * 0 on success otherwise a negative error code
+ */
+int ahci_platform_init_host(struct platform_device *pdev,
+                            struct ahci_host_priv *hpriv,
+                            const struct ata_port_info *pi_template,
+                            unsigned int force_port_map,
+                            unsigned int mask_port_map)
+{
+        struct device *dev = &pdev->dev;
+        struct ata_port_info pi = *pi_template;
+        const struct ata_port_info *ppi[] = { &pi, NULL };
+        struct ata_host *host;
+        int i, irq, n_ports, rc;
 
-        ahci_save_initial_config(dev, hpriv,
-                pdata ? pdata->force_port_map : 0,
-                pdata ? pdata->mask_port_map  : 0);
+        irq = platform_get_irq(pdev, 0);
+        if (irq <= 0) {
+                dev_err(dev, "no irq\n");
+                return -EINVAL;
+        }
 
         /* prepare host */
+        hpriv->flags |= (unsigned long)pi.private_data;
+
+        ahci_save_initial_config(dev, hpriv, force_port_map, mask_port_map);
+
         if (hpriv->cap & HOST_CAP_NCQ)
                 pi.flags |= ATA_FLAG_NCQ;
 
@@ -307,10 +329,8 @@ static int ahci_probe(struct platform_device *pdev)
         n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
 
         host = ata_host_alloc_pinfo(dev, ppi, n_ports);
-        if (!host) {
-                rc = -ENOMEM;
-                goto pdata_exit;
-        }
+        if (!host)
+                return -ENOMEM;
 
         host->private_data = hpriv;
 
@@ -325,7 +345,8 @@ static int ahci_probe(struct platform_device *pdev)
         for (i = 0; i < host->n_ports; i++) {
                 struct ata_port *ap = host->ports[i];
 
-                ata_port_desc(ap, "mmio %pR", mem);
+                ata_port_desc(ap, "mmio %pR",
+                              platform_get_resource(pdev, IORESOURCE_MEM, 0));
                 ata_port_desc(ap, "port 0x%x", 0x100 + ap->port_no * 0x80);
 
                 /* set enclosure management message type */
@@ -339,13 +360,53 @@ static int ahci_probe(struct platform_device *pdev)
 
         rc = ahci_reset_controller(host);
         if (rc)
-                goto pdata_exit;
+                return rc;
 
         ahci_init_controller(host);
         ahci_print_info(host, "platform");
 
-        rc = ata_host_activate(host, irq, ahci_interrupt, IRQF_SHARED,
-                               &ahci_platform_sht);
+        return ata_host_activate(host, irq, ahci_interrupt, IRQF_SHARED,
+                                 &ahci_platform_sht);
+}
+EXPORT_SYMBOL_GPL(ahci_platform_init_host);
+
+static int ahci_probe(struct platform_device *pdev)
+{
+        struct device *dev = &pdev->dev;
+        struct ahci_platform_data *pdata = dev_get_platdata(dev);
+        const struct platform_device_id *id = platform_get_device_id(pdev);
+        const struct ata_port_info *pi_template;
+        struct ahci_host_priv *hpriv;
+        int rc;
+
+        hpriv = ahci_platform_get_resources(pdev);
+        if (IS_ERR(hpriv))
+                return PTR_ERR(hpriv);
+
+        rc = ahci_platform_enable_resources(hpriv);
+        if (rc)
+                return rc;
+
+        /*
+         * Some platforms might need to prepare for mmio region access,
+         * which could be done in the following init call. So, the mmio
+         * region shouldn't be accessed before init (if provided) has
+         * returned successfully.
+         */
+        if (pdata && pdata->init) {
+                rc = pdata->init(dev, hpriv->mmio);
+                if (rc)
+                        goto disable_resources;
+        }
+
+        if (pdata && pdata->ata_port_info)
+                pi_template = pdata->ata_port_info;
+        else
+                pi_template = &ahci_port_info[id ? id->driver_data : 0];
+
+        rc = ahci_platform_init_host(pdev, hpriv, pi_template,
+                                     pdata ? pdata->force_port_map : 0,
+                                     pdata ? pdata->mask_port_map  : 0);
         if (rc)
                 goto pdata_exit;
 
@@ -355,8 +416,6 @@ pdata_exit:
                 pdata->exit(dev);
 disable_resources:
         ahci_platform_disable_resources(hpriv);
-free_clk:
-        ahci_put_clks(hpriv);
         return rc;
 }
 
@@ -370,7 +429,6 @@ static void ahci_host_stop(struct ata_host *host)
                 pdata->exit(dev);
 
         ahci_platform_disable_resources(hpriv);
-        ahci_put_clks(hpriv);
 }
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h
index b674b01ce9bc..b80c51c20f76 100644
--- a/include/linux/ahci_platform.h
+++ b/include/linux/ahci_platform.h
@@ -20,7 +20,14 @@
 struct device;
 struct ata_port_info;
 struct ahci_host_priv;
+struct platform_device;
 
+/*
+ * Note ahci_platform_data is deprecated, it is only kept around for use
+ * by the old da850 and spear13xx ahci code.
+ * New drivers should instead declare their own platform_driver struct, and
+ * use ahci_platform* functions in their own probe, suspend and resume methods.
+ */
 struct ahci_platform_data {
         int (*init)(struct device *dev, void __iomem *addr);
         void (*exit)(struct device *dev);
@@ -35,5 +42,12 @@ int ahci_platform_enable_clks(struct ahci_host_priv *hpriv);
 void ahci_platform_disable_clks(struct ahci_host_priv *hpriv);
 int ahci_platform_enable_resources(struct ahci_host_priv *hpriv);
 void ahci_platform_disable_resources(struct ahci_host_priv *hpriv);
+struct ahci_host_priv *ahci_platform_get_resources(
+        struct platform_device *pdev);
+int ahci_platform_init_host(struct platform_device *pdev,
+                            struct ahci_host_priv *hpriv,
+                            const struct ata_port_info *pi_template,
+                            unsigned int force_port_map,
+                            unsigned int mask_port_map);
 
 #endif /* _AHCI_PLATFORM_H */