nvmem: sunxi_sid: Dynamically allocate nvmem_config structure

The sunxi_sid driver currently uses a statically allocated nvmem_config
structure that is updated at probe time. This is sub-optimal as it
limits the driver to one instance, and also takes up space even if the
device is not present.

Modify the driver to allocate the nvmem_config structure at probe time,
plugging in the desired parameters along the way.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/sunxi_sid.c

@@ -35,13 +35,6 @@
 #define SUN8I_SID_OP_LOCK	(0xAC << 8)
 #define SUN8I_SID_READ		BIT(1)
 
-static struct nvmem_config econfig = {
-	.name = "sunxi-sid",
-	.read_only = true,
-	.stride = 4,
-	.word_size = 1,
-};
-
 struct sunxi_sid_cfg {
 	u32	value_offset;
 	u32	size;
@@ -150,6 +143,7 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct resource *res;
+	struct nvmem_config *nvmem_cfg;
 	struct nvmem_device *nvmem;
 	struct sunxi_sid *sid;
 	int size;
@@ -172,14 +166,23 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 
 	size = cfg->size;
 
-	econfig.size = size;
-	econfig.dev = dev;
+	nvmem_cfg = devm_kzalloc(dev, sizeof(*nvmem_cfg), GFP_KERNEL);
+	if (!nvmem_cfg)
+		return -ENOMEM;
+
+	nvmem_cfg->dev = dev;
+	nvmem_cfg->name = "sunxi-sid";
+	nvmem_cfg->read_only = true;
+	nvmem_cfg->size = cfg->size;
+	nvmem_cfg->word_size = 1;
+	nvmem_cfg->stride = 4;
+	nvmem_cfg->priv = sid;
 	if (cfg->need_register_readout)
-		econfig.reg_read = sun8i_sid_read_by_reg;
+		nvmem_cfg->reg_read = sun8i_sid_read_by_reg;
 	else
-		econfig.reg_read = sunxi_sid_read;
-	econfig.priv = sid;
-	nvmem = devm_nvmem_register(dev, &econfig);
+		nvmem_cfg->reg_read = sunxi_sid_read;
+
+	nvmem = devm_nvmem_register(dev, nvmem_cfg);
 	if (IS_ERR(nvmem))
 		return PTR_ERR(nvmem);
 
@@ -187,8 +190,7 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 	if (!randomness)
 		return -ENOMEM;
 
-	econfig.reg_read(sid, 0, randomness, size);
-
+	nvmem_cfg->reg_read(sid, 0, randomness, size);
 	add_device_randomness(randomness, size);
 	kfree(randomness);