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authorIcenowy Zheng <icenowy@aosc.xyz>2017-03-31 13:44:48 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-04-08 17:51:48 +0200
commit1a9636426b9f994d57dfe5a64e3f4644747a2e95 (patch)
tree7f7b47253b29a169a9f21f82ee33f42822b71f74
parent4a72cda530f87ee0d96c4b79b9e1a865f7761659 (diff)
nvmem: sunxi-sid: add support for H3's SID controller
The H3 SoC have a bigger SID controller, which has its direct read address at 0x200 position in the SID block, not 0x0. Also, H3 SID controller has some silicon bug that makes the direct read value wrong at cold boot, add code to workaround the bug. (This bug has already been fixed on A64 and later SoCs) Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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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