[PATCH linux-next 2/3] mtd: brcmnand: Request and enable the clock if present

Simon Arlott
2015-12-03T20:01:25Z

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>
---
Removed ctrl->clk not NULL check.

drivers/mtd/nand/brcmnand/brcmnand.c | 64 ++++++++++++++++++++++++++++--------
1 file changed, 50 insertions(+), 14 deletions(-)

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index 35d78f7..cf0374e 100644
--- 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;
--
2.1.4

--
Simon Arlott