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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);

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