mtd: brcmnand: Request and enable the clock if present

Attempt to enable a clock named "nand" as some SoCs have a clock for the
controller that needs to be enabled.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 190a99a66010bcaacf04d0d7a6678071f15e80ca..dca816298aef0709f6e9d758d82508385d716865 100644 (file)
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -11,6 +11,7 @@
  * GNU General Public License for more details.
  */
 
+#include <linux/clk.h>
 #include <linux/version.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -122,6 +123,9 @@ struct brcmnand_controller {
        /* Some SoCs provide custom interrupt status register(s) */
        struct brcmnand_soc     *soc;
 
+       /* Some SoCs have a gateable clock for the controller */
+       struct clk              *clk;
+
        int                     cmd_pending;
        bool                    dma_pending;
        struct completion       done;
@@ -2127,10 +2131,24 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        if (IS_ERR(ctrl->nand_base))
                return PTR_ERR(ctrl->nand_base);
 
+       /* Enable clock before using NAND registers */
+       ctrl->clk = devm_clk_get(dev, "nand");
+       if (!IS_ERR(ctrl->clk)) {
+               ret = clk_prepare_enable(ctrl->clk);
+               if (ret)
+                       return ret;
+       } else {
+               ret = PTR_ERR(ctrl->clk);
+               if (ret == -EPROBE_DEFER)
+                       return ret;
+
+               ctrl->clk = NULL;
+       }
+
        /* Initialize NAND revision */
        ret = brcmnand_revision_init(ctrl);
        if (ret)
-               return ret;
+               goto err;
 
        /*
         * Most chips have this cache at a fixed offset within 'nand' block.
@@ -2139,8 +2157,10 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "nand-cache");
        if (res) {
                ctrl->nand_fc = devm_ioremap_resource(dev, res);
-               if (IS_ERR(ctrl->nand_fc))
-                       return PTR_ERR(ctrl->nand_fc);
+               if (IS_ERR(ctrl->nand_fc)) {
+                       ret = PTR_ERR(ctrl->nand_fc);
+                       goto err;
+               }
        } else {
                ctrl->nand_fc = ctrl->nand_base +
                                ctrl->reg_offsets[BRCMNAND_FC_BASE];
@@ -2150,8 +2170,10 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "flash-dma");
        if (res) {
                ctrl->flash_dma_base = devm_ioremap_resource(dev, res);
-               if (IS_ERR(ctrl->flash_dma_base))
-                       return PTR_ERR(ctrl->flash_dma_base);
+               if (IS_ERR(ctrl->flash_dma_base)) {
+                       ret = PTR_ERR(ctrl->flash_dma_base);
+                       goto err;
+               }
 
                flash_dma_writel(ctrl, FLASH_DMA_MODE, 1); /* linked-list */
                flash_dma_writel(ctrl, FLASH_DMA_ERROR_STATUS, 0);
@@ -2160,13 +2182,16 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
                ctrl->dma_desc = dmam_alloc_coherent(dev,
                                                     sizeof(*ctrl->dma_desc),
                                                     &ctrl->dma_pa, GFP_KERNEL);
-               if (!ctrl->dma_desc)
-                       return -ENOMEM;
+               if (!ctrl->dma_desc) {
+                       ret = -ENOMEM;
+                       goto err;
+               }
 
                ctrl->dma_irq = platform_get_irq(pdev, 1);
                if ((int)ctrl->dma_irq < 0) {
                        dev_err(dev, "missing FLASH_DMA IRQ\n");
-                       return -ENODEV;
+                       ret = -ENODEV;
+                       goto err;
                }
 
                ret = devm_request_irq(dev, ctrl->dma_irq,
@@ -2175,7 +2200,7 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
                if (ret < 0) {
                        dev_err(dev, "can't allocate IRQ %d: error %d\n",
                                        ctrl->dma_irq, ret);
-                       return ret;
+                       goto err;
                }
 
                dev_info(dev, "enabling FLASH_DMA\n");
@@ -2199,7 +2224,8 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        ctrl->irq = platform_get_irq(pdev, 0);
        if ((int)ctrl->irq < 0) {
                dev_err(dev, "no IRQ defined\n");
-               return -ENODEV;
+               ret = -ENODEV;
+               goto err;
        }
 
        /*
@@ -2223,7 +2249,7 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        if (ret < 0) {
                dev_err(dev, "can't allocate IRQ %d: error %d\n",
                        ctrl->irq, ret);
-               return ret;
+               goto err;
        }
 
        for_each_available_child_of_node(dn, child) {
@@ -2233,7 +2259,8 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
                        host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL);
                        if (!host) {
                                of_node_put(child);
-                               return -ENOMEM;
+                               ret = -ENOMEM;
+                               goto err;
                        }
                        host->pdev = pdev;
                        host->ctrl = ctrl;
@@ -2249,10 +2276,17 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc)
        }
 
        /* No chip-selects could initialize properly */
-       if (list_empty(&ctrl->host_list))
-               return -ENODEV;
+       if (list_empty(&ctrl->host_list)) {
+               ret = -ENODEV;
+               goto err;
+       }
 
        return 0;
+
+err:
+       clk_disable_unprepare(ctrl->clk);
+       return ret;
+
 }
 EXPORT_SYMBOL_GPL(brcmnand_probe);
 
@@ -2264,6 +2298,8 @@ int brcmnand_remove(struct platform_device *pdev)
        list_for_each_entry(host, &ctrl->host_list, node)
                nand_release(&host->mtd);
 
+       clk_disable_unprepare(ctrl->clk);
+
        dev_set_drvdata(&pdev->dev, NULL);
 
        return 0;