nvmem: mtk-efuse: remove nvmem regmap dependency

Regmap raw accessors are bus specific implementations, using regmap raw
apis in nvmem breaks nvmem providers based on regmap mmio.
This patch moves to nvmem support in the driver to use callback
instead of regmap, which is what the nvmem core supports now.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 32 insertions, 16 deletions

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 3041d48e7155..5ff21892bcd6 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -50,7 +50,6 @@ config MTK_EFUSE
         tristate "Mediatek SoCs EFUSE support"
         depends on ARCH_MEDIATEK || COMPILE_TEST
         depends on HAS_IOMEM
-        select REGMAP_MMIO
         help
           This is a driver to access hardware related data like sensor
           calibration, HDMI impedance etc.
diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
index 9c49369beea5..32fd572e18c5 100644
--- a/drivers/nvmem/mtk-efuse.c
+++ b/drivers/nvmem/mtk-efuse.c
@@ -14,15 +14,35 @@
 
 #include <linux/device.h>
 #include <linux/module.h>
+#include <linux/io.h>
 #include <linux/nvmem-provider.h>
 #include <linux/platform_device.h>
-#include <linux/regmap.h>
 
-static struct regmap_config mtk_regmap_config = {
-        .reg_bits = 32,
-        .val_bits = 32,
-        .reg_stride = 4,
-};
+static int mtk_reg_read(void *context,
+                        unsigned int reg, void *_val, size_t bytes)
+{
+        void __iomem *base = context;
+        u32 *val = _val;
+        int i = 0, words = bytes / 4;
+
+        while (words--)
+                *val++ = readl(base + reg + (i++ * 4));
+
+        return 0;
+}
+
+static int mtk_reg_write(void *context,
+                         unsigned int reg, void *_val, size_t bytes)
+{
+        void __iomem *base = context;
+        u32 *val = _val;
+        int i = 0, words = bytes / 4;
+
+        while (words--)
+                writel(*val++, base + reg + (i++ * 4));
+
+        return 0;
+}
 
 static int mtk_efuse_probe(struct platform_device *pdev)
 {
@@ -30,7 +50,6 @@ static int mtk_efuse_probe(struct platform_device *pdev)
         struct resource *res;
         struct nvmem_device *nvmem;
         struct nvmem_config *econfig;
-        struct regmap *regmap;
         void __iomem *base;
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -42,14 +61,12 @@ static int mtk_efuse_probe(struct platform_device *pdev)
         if (!econfig)
                 return -ENOMEM;
 
-        mtk_regmap_config.max_register = resource_size(res) - 1;
-
-        regmap = devm_regmap_init_mmio(dev, base, &mtk_regmap_config);
-        if (IS_ERR(regmap)) {
-                dev_err(dev, "regmap init failed\n");
-                return PTR_ERR(regmap);
-        }
-
+        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->dev = dev;
         econfig->owner = THIS_MODULE;
         nvmem = nvmem_register(econfig);