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-rw-r--r--Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt6
-rw-r--r--drivers/nvmem/sunxi_sid.c62
2 files changed, 67 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt b/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt
index d543ed3f5363..ef06d061913c 100644
--- a/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt
+++ b/Documentation/devicetree/bindings/nvmem/allwinner,sunxi-sid.txt
@@ -1,7 +1,11 @@
 Allwinner sunxi-sid
 
 Required properties:
-- compatible: "allwinner,sun4i-a10-sid" or "allwinner,sun7i-a20-sid"
+- compatible: Should be one of the following:
+  "allwinner,sun4i-a10-sid"
+  "allwinner,sun7i-a20-sid"
+  "allwinner,sun8i-h3-sid"
+
 - reg: Should contain registers location and length
 
 = Data cells =
diff --git a/drivers/nvmem/sunxi_sid.c b/drivers/nvmem/sunxi_sid.c
index 69524b67007f..0d6648be93b8 100644
--- a/drivers/nvmem/sunxi_sid.c
+++ b/drivers/nvmem/sunxi_sid.c
@@ -17,6 +17,7 @@
 
 #include <linux/device.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/nvmem-provider.h>
 #include <linux/of.h>
@@ -25,6 +26,15 @@
 #include <linux/slab.h>
 #include <linux/random.h>
 
+/* Registers and special values for doing register-based SID readout on H3 */
+#define SUN8I_SID_PRCTL		0x40
+#define SUN8I_SID_RDKEY		0x60
+
+#define SUN8I_SID_OFFSET_MASK	0x1FF
+#define SUN8I_SID_OFFSET_SHIFT	16
+#define SUN8I_SID_OP_LOCK	(0xAC << 8)
+#define SUN8I_SID_READ		BIT(1)
+
 static struct nvmem_config econfig = {
 	.name = "sunxi-sid",
 	.read_only = true,
@@ -34,11 +44,14 @@ static struct nvmem_config econfig = {
 };
 
 struct sunxi_sid_cfg {
+	u32	value_offset;
 	u32	size;
+	bool	need_register_readout;
 };
 
 struct sunxi_sid {
 	void __iomem		*base;
+	u32			value_offset;
 };
 
 /* We read the entire key, due to a 32 bit read alignment requirement. Since we
@@ -63,12 +76,36 @@ static int sunxi_sid_read(void *context, unsigned int offset,
 	struct sunxi_sid *sid = context;
 	u8 *buf = val;
 
+	/* Offset the read operation to the real position of SID */
+	offset += sid->value_offset;
+
 	while (bytes--)
 		*buf++ = sunxi_sid_read_byte(sid, offset++);
 
 	return 0;
 }
 
+static int sun8i_sid_register_readout(const struct sunxi_sid *sid,
+				      const unsigned int word)
+{
+	u32 reg_val;
+	int ret;
+
+	/* Set word, lock access, and set read command */
+	reg_val = (word & SUN8I_SID_OFFSET_MASK)
+		  << SUN8I_SID_OFFSET_SHIFT;
+	reg_val |= SUN8I_SID_OP_LOCK | SUN8I_SID_READ;
+	writel(reg_val, sid->base + SUN8I_SID_PRCTL);
+
+	ret = readl_poll_timeout(sid->base + SUN8I_SID_PRCTL, reg_val,
+				 !(reg_val & SUN8I_SID_READ), 100, 250000);
+	if (ret)
+		return ret;
+
+	writel(0, sid->base + SUN8I_SID_PRCTL);
+	return 0;
+}
+
 static int sunxi_sid_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -86,6 +123,7 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 	cfg = of_device_get_match_data(dev);
 	if (!cfg)
 		return -EINVAL;
+	sid->value_offset = cfg->value_offset;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	sid->base = devm_ioremap_resource(dev, res);
@@ -94,6 +132,23 @@ static int sunxi_sid_probe(struct platform_device *pdev)
 
 	size = cfg->size;
 
+	if (cfg->need_register_readout) {
+		/*
+		 * H3's SID controller have a bug that the value at 0x200
+		 * offset is not the correct value when the hardware is reseted.
+		 * However, after doing a register-based read operation, the
+		 * value become right.
+		 * Do a full read operation here, but ignore its value
+		 * (as it's more fast to read by direct MMIO value than
+		 * with registers)
+		 */
+		for (i = 0; i < (size >> 2); i++) {
+			ret = sun8i_sid_register_readout(sid, i);
+			if (ret)
+				return ret;
+		}
+	}
+
 	econfig.size = size;
 	econfig.dev = dev;
 	econfig.reg_read = sunxi_sid_read;
@@ -138,9 +193,16 @@ static const struct sunxi_sid_cfg sun7i_a20_cfg = {
 	.size = 0x200,
 };
 
+static const struct sunxi_sid_cfg sun8i_h3_cfg = {
+	.value_offset = 0x200,
+	.size = 0x100,
+	.need_register_readout = true,
+};
+
 static const struct of_device_id sunxi_sid_of_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-sid", .data = &sun4i_a10_cfg },
 	{ .compatible = "allwinner,sun7i-a20-sid", .data = &sun7i_a20_cfg },
+	{ .compatible = "allwinner,sun8i-h3-sid", .data = &sun8i_h3_cfg },
 	{/* sentinel */},
 };
 MODULE_DEVICE_TABLE(of, sunxi_sid_of_match);