From: ZhengShunQian <zhen...@rock-chips.com>

There are some SoC specified values store in eFuse,
such as the cpu_leakage and cpu_version,
this driver can expose these values to /sys base on nvmem.

Also add the docs of efuse bindings and the rk3288's efuse config.

Signed-off-by: Caesar Wang <caesar.w...@rock-chips.com>
Signed-off-by: ZhengShunQian <zhen...@rock-chips.com>
---
 .../devicetree/bindings/nvmem/rockchip-efuse.txt   |  36 +++++
 arch/arm/boot/dts/rk3288.dtsi                      |  13 ++
 drivers/nvmem/Kconfig                              |  10 ++
 drivers/nvmem/Makefile                             |   2 +
 drivers/nvmem/rockchip-efuse.c                     | 155 +++++++++++++++++++++
 5 files changed, 216 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt
 create mode 100644 drivers/nvmem/rockchip-efuse.c

diff --git a/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt 
b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt
new file mode 100644
index 0000000..bb487ec
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/rockchip-efuse.txt
@@ -0,0 +1,36 @@
+= Rockchip eFuse device tree bindings =
+
+Required properties:
+- compatible: Should be "rockchip,rockchip-efuse"
+- reg: Should contain the registers location and exact eFuse size
+
+= Data cells =
+Are child nodes of eFuse, bindings of which as described in
+bindings/nvmem/nvmem.txt
+
+Example:
+
+       efuse: efuse@ffb40000 {
+               compatible = "rockchip,rockchip-efuse";
+               reg = <0xffb40000 0x20>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               clocks = <&cru PCLK_EFUSE256>;
+               clock-names = "pclk_efuse_256";
+
+               /* Data cells */
+               cpu_leakage: cpu_leakage {
+                       reg = <0x17 0x1>;
+               };
+       };
+
+= Data consumers =
+Are device nodes which consume nvmem data cells.
+
+Example:
+
+       cpu_leakage {
+               ...
+               nvmem-cells = <&cpu_leakage>;
+               nvmem-cell-names = "cpu_leakage";
+       };
diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 2db91c9..272c0b5 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -749,6 +749,19 @@
                interrupts = <GIC_PPI 9 0xf04>;
        };
 
+       efuse: efuse@ffb40000 {
+               compatible = "rockchip,rockchip-efuse";
+               reg = <0xffb40000 0x20>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               clocks = <&cru PCLK_EFUSE256>;
+               clock-names = "pclk_efuse_256";
+
+               cpu_leakage: cpu_leakage {
+                       reg = <0x17 0x1>;
+               };
+       };
+
        usbphy: phy {
                compatible = "rockchip,rk3288-usb-phy";
                rockchip,grf = <&grf>;
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 8db2978..98f1fac 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -36,4 +36,14 @@ config NVMEM_SUNXI_SID
          This driver can also be built as a module. If so, the module
          will be called nvmem_sunxi_sid.
 
+config ROCKCHIP_EFUSE
+       tristate "Rockchip eFuse Support"
+       depends on ARCH_ROCKCHIP || COMPILE_TEST
+       help
+         This is a simple drive to dump specified values of Rockchip SoC
+         from eFuse, such as cpu-leakage.
+
+         This driver can also be built as a module. If so, the module
+         will be called nvmem_rockchip_efuse.
+
 endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 4328b93..093a528 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -10,3 +10,5 @@ obj-$(CONFIG_QCOM_QFPROM)     += nvmem_qfprom.o
 nvmem_qfprom-y                 := qfprom.o
 obj-$(CONFIG_NVMEM_SUNXI_SID)  += nvmem_sunxi_sid.o
 nvmem_sunxi_sid-y              := sunxi_sid.o
+obj-$(CONFIG_ROCKCHIP_EFUSE)   += nvmem_rockchip_efuse.o
+nvmem_rockchip_efuse-y         := rockchip-efuse.o
diff --git a/drivers/nvmem/rockchip-efuse.c b/drivers/nvmem/rockchip-efuse.c
new file mode 100644
index 0000000..30ee772
--- /dev/null
+++ b/drivers/nvmem/rockchip-efuse.c
@@ -0,0 +1,155 @@
+/*
+ * Rockchip eFuse Driver
+ *
+ * Copyright (c) 2015 Rockchip Electronics Co. Ltd.
+ * Author: Caesar Wang <w...@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/nvmem-provider.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+
+#define EFUSE_A_SHIFT                  6
+#define EFUSE_A_MASK                   0x3ff
+#define EFUSE_PGENB                    BIT(3)
+#define EFUSE_LOAD                     BIT(2)
+#define EFUSE_STROBE                   BIT(1)
+#define EFUSE_CSB                      BIT(0)
+
+#define REG_EFUSE_CTRL                 0x0000
+#define REG_EFUSE_DOUT                 0x0004
+
+static int rockchip_efuse_write(void *context, const void *data, size_t count)
+{
+       /* Nothing TBD, Read-Only */
+       return 0;
+}
+
+static int rockchip_efuse_read(void *context,
+                              const void *reg, size_t reg_size,
+                              void *val, size_t val_size)
+{
+       unsigned int offset = *(u32 *)reg;
+       void __iomem *base = context;
+       u8 *buf = val;
+
+       writel(EFUSE_LOAD | EFUSE_PGENB, base + REG_EFUSE_CTRL);
+       udelay(1);
+       while (val_size) {
+               writel(readl(base + REG_EFUSE_CTRL) &
+                            (~(EFUSE_A_MASK << EFUSE_A_SHIFT)),
+                            base + REG_EFUSE_CTRL);
+               writel(readl(base + REG_EFUSE_CTRL) |
+                            ((offset & EFUSE_A_MASK) << EFUSE_A_SHIFT),
+                            base + REG_EFUSE_CTRL);
+               udelay(1);
+               writel(readl(base + REG_EFUSE_CTRL) |
+                            EFUSE_STROBE, base + REG_EFUSE_CTRL);
+               udelay(1);
+               *buf++ = readb(base + REG_EFUSE_DOUT);
+               writel(readl(base + REG_EFUSE_CTRL) &
+                    (~EFUSE_STROBE), base + REG_EFUSE_CTRL);
+               udelay(1);
+
+               val_size -= 1;
+               offset += 1;
+       }
+
+       /* Switch to standby mode */
+       writel(EFUSE_PGENB | EFUSE_CSB, base + REG_EFUSE_CTRL);
+
+       return 0;
+}
+
+static struct regmap_bus rockchip_efuse_bus = {
+       .read = rockchip_efuse_read,
+       .write = rockchip_efuse_write,
+       .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+       .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+struct regmap_config rockchip_efuse_regmap_config = {
+       .reg_bits = 32,
+       .reg_stride = 1,
+       .val_bits = 8,
+};
+
+static struct nvmem_config econfig = {
+       .name = "rockchip-efuse",
+       .owner = THIS_MODULE,
+       .read_only = true,
+};
+
+static const struct of_device_id rockchip_efuse_match[] = {
+       { .compatible = "rockchip,rockchip-efuse",},
+       { /* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, rockchip_efuse_match);
+
+int rockchip_efuse_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct resource *res;
+       struct nvmem_device *nvmem;
+       struct regmap *regmap;
+       void __iomem *base;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       base = devm_ioremap_resource(dev, res);
+
+       if (IS_ERR(base))
+               return PTR_ERR(base);
+
+       rockchip_efuse_regmap_config.max_register = resource_size(res) - 1;
+
+       regmap = devm_regmap_init(dev, &rockchip_efuse_bus,
+                                 base, &rockchip_efuse_regmap_config);
+       if (IS_ERR(regmap)) {
+               dev_err(dev, "regmap init failed\n");
+               return PTR_ERR(regmap);
+       }
+       econfig.dev = dev;
+       nvmem = nvmem_register(&econfig);
+       if (IS_ERR(nvmem))
+               return PTR_ERR(nvmem);
+
+       platform_set_drvdata(pdev, nvmem);
+
+       return 0;
+}
+
+int rockchip_efuse_remove(struct platform_device *pdev)
+{
+       struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+       return nvmem_unregister(nvmem);
+}
+
+static struct platform_driver rockchip_efuse_driver = {
+       .probe = rockchip_efuse_probe,
+       .remove = rockchip_efuse_remove,
+       .driver = {
+               .name = "rockchip-efuse",
+               .of_match_table = rockchip_efuse_match,
+       },
+};
+
+module_platform_driver(rockchip_efuse_driver);
+MODULE_DESCRIPTION("rockchip_efuse driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to