[PATCH 3/5] nvmem: mtk-efuse: fix different address space warnings of sparse

From: Masahiro Yamada
Date: Mon Sep 11 2017 - 09:02:43 EST


Fix the following sparse warnings:

drivers/nvmem/mtk-efuse.c:24:30: warning: incorrect type in initializer (different address spaces)
drivers/nvmem/mtk-efuse.c:24:30: expected void [noderef] <asn:2>*base
drivers/nvmem/mtk-efuse.c:24:30: got void *context
drivers/nvmem/mtk-efuse.c:37:30: warning: incorrect type in initializer (different address spaces)
drivers/nvmem/mtk-efuse.c:37:30: expected void [noderef] <asn:2>*base
drivers/nvmem/mtk-efuse.c:37:30: got void *context
drivers/nvmem/mtk-efuse.c:69:23: warning: incorrect type in assignment (different address spaces)
drivers/nvmem/mtk-efuse.c:69:23: expected void *priv
drivers/nvmem/mtk-efuse.c:69:23: got void [noderef] <asn:2>*[assigned] base

The type of nvmem_config->priv is (void *), so sparse complains
about assignment of the base address with (void __iomem *) type.

Even if we cast it out, sparse still warns:
warning: cast removes address space of expression

Of course, we can shut up the sparse by marking __force, but a more
correct way is to put the base address into driver private data.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

drivers/nvmem/mtk-efuse.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
index fa7a0f6..c4058b5 100644
--- a/drivers/nvmem/mtk-efuse.c
+++ b/drivers/nvmem/mtk-efuse.c
@@ -18,15 +18,19 @@
#include <linux/nvmem-provider.h>
#include <linux/platform_device.h>

+struct mtk_efuse_priv {
+ void __iomem *base;
+};
+
static int mtk_reg_read(void *context,
unsigned int reg, void *_val, size_t bytes)
{
- void __iomem *base = context;
+ struct mtk_efuse_priv *priv = context;
u32 *val = _val;
int i = 0, words = bytes / 4;

while (words--)
- *val++ = readl(base + reg + (i++ * 4));
+ *val++ = readl(priv->base + reg + (i++ * 4));

return 0;
}
@@ -34,12 +38,12 @@ static int mtk_reg_read(void *context,
static int mtk_reg_write(void *context,
unsigned int reg, void *_val, size_t bytes)
{
- void __iomem *base = context;
+ struct mtk_efuse_priv *priv = context;
u32 *val = _val;
int i = 0, words = bytes / 4;

while (words--)
- writel(*val++, base + reg + (i++ * 4));
+ writel(*val++, priv->base + reg + (i++ * 4));

return 0;
}
@@ -50,19 +54,23 @@ static int mtk_efuse_probe(struct platform_device *pdev)
struct resource *res;
struct nvmem_device *nvmem;
struct nvmem_config econfig = {};
- void __iomem *base;
+ struct mtk_efuse_priv *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- base = devm_ioremap_resource(dev, res);
- if (IS_ERR(base))
- return PTR_ERR(base);
+ priv->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);

econfig.stride = 4;
econfig.word_size = 4;
econfig.reg_read = mtk_reg_read;
econfig.reg_write = mtk_reg_write;
econfig.size = resource_size(res);
- econfig.priv = base;
+ econfig.priv = priv;
econfig.dev = dev;
econfig.owner = THIS_MODULE;
nvmem = nvmem_register(&econfig);
--
2.7.4