[RFC PATCH v6 3/3] drivers: nvmem: Add Vybrid OCOTP support
From: Sanchayan Maity
Date: Mon Jun 29 2015 - 07:26:09 EST
The patch adds support for the On Chip One Time Programmable Peripheral
(OCOTP) on the Vybrid platform.
Signed-off-by: Sanchayan Maity <maitysanchayan@xxxxxxxxx>
---
drivers/nvmem/Kconfig | 10 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/vf610-ocotp.c | 250 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 262 insertions(+)
create mode 100644 drivers/nvmem/vf610-ocotp.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 17f1a57..84c830d 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -33,4 +33,14 @@ config NVMEM_SUNXI_SID
This driver can also be built as a module. If so, the module
will be called eeprom-sunxi-sid.
+config NVMEM_VF610_OCOTP
+ tristate "VF610 SoCs OCOTP support"
+ depends on SOC_VF610
+ help
+ This is a driver for the 'OCOTP' available on various Vybrid
+ devices.
+
+ This driver can also be built as a module. If so, the module
+ will be called nvmem-vf610-ocotp.
+
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index cc46791..a9ed113 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -11,3 +11,5 @@ 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_NVMEM_VF610_OCOTP) += nvmem-vf610-ocotp.o
+nvmem-vf610-ocotp-y := vf610-ocotp.o
diff --git a/drivers/nvmem/vf610-ocotp.c b/drivers/nvmem/vf610-ocotp.c
new file mode 100644
index 0000000..b7a782c
--- /dev/null
+++ b/drivers/nvmem/vf610-ocotp.c
@@ -0,0 +1,250 @@
+/*
+ * Copyright (C) 2015 Sanchayan Maity <sanchayan.maity@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 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/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/nvmem-provider.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* OCOTP Register Offsets */
+#define OCOTP_CTRL_REG 0x00
+#define OCOTP_CTRL_SET 0x04
+#define OCOTP_CTRL_CLR 0x08
+#define OCOTP_TIMING 0x10
+#define OCOTP_DATA 0x20
+#define OCOTP_READ_CTRL_REG 0x30
+#define OCOTP_READ_FUSE_DATA 0x40
+
+/* OCOTP Register bits and masks */
+#define OCOTP_CTRL_WR_UNLOCK 16
+#define OCOTP_CTRL_WR_UNLOCK_KEY 0x3E77
+#define OCOTP_CTRL_WR_UNLOCK_MASK 0xFFFF0000
+#define OCOTP_CTRL_ADDR 0
+#define OCOTP_CTRL_ADDR_MASK 0x7F
+#define OCOTP_CTRL_RELOAD_SHADOWS (0x1 << 10)
+#define OCOTP_CTRL_ERROR (0x1 << 9)
+#define OCOTP_CTRL_BUSY (0x1 << 8)
+
+#define OCOTP_TIMING_STROBE_READ 16
+#define OCOTP_TIMING_STROBE_READ_MASK 0x003F0000
+#define OCOTP_TIMING_RELAX 12
+#define OCOTP_TIMING_RELAX_MASK 0x0000F000
+#define OCOTP_TIMING_STROBE_PROG 0
+#define OCOTP_TIMING_STROBE_PROG_MASK 0x00000FFF
+
+#define OCOTP_READ_CTRL_READ_FUSE 0x1
+
+#define VF610_OCOTP_TIMEOUT 100000
+
+#define BF(value, field) (((value) << field) & field##_MASK)
+
+#define DEF_RELAX 20
+
+struct vf610_ocotp_dev {
+ void __iomem *base;
+ struct clk *clk;
+ struct device *dev;
+ struct resource *res;
+ struct regmap *regmap;
+ struct nvmem_device *nvmem;
+};
+
+static int ocotp_timing;
+
+static u8 valid_fuse_addr[] = {
+ 0x00, 0x01, 0x02, 0x04, 0x0F, 0x20, 0x21, 0x22, 0x23, 0x24,
+ 0x25, 0x26, 0x27, 0x28, 0x2F, 0x38, 0x39, 0x3A, 0x3B, 0x3C,
+ 0x3D, 0x3E, 0x3F
+};
+
+static int vf610_ocotp_wait_busy(void __iomem *base)
+{
+ int timeout = VF610_OCOTP_TIMEOUT;
+
+ while ((readl(base) & OCOTP_CTRL_BUSY) && --timeout)
+ udelay(10);
+
+ if (!timeout) {
+ writel(OCOTP_CTRL_ERROR, base + OCOTP_CTRL_CLR);
+ return -ETIMEDOUT;
+ }
+
+ udelay(10);
+
+ return 0;
+}
+
+static int vf610_ocotp_calculate_timing(struct vf610_ocotp_dev *ocotp_dev)
+{
+ u32 clk_rate;
+ u32 relax, strobe_read, strobe_prog;
+ u32 timing;
+
+ clk_rate = clk_get_rate(ocotp_dev->clk);
+
+ relax = clk_rate / (1000000000 / DEF_RELAX) - 1;
+ strobe_prog = clk_rate / (1000000000 / 10000) + 2 * (DEF_RELAX + 1) - 1;
+ strobe_read = clk_rate / (1000000000 / 40) + 2 * (DEF_RELAX + 1) - 1;
+
+ timing = BF(relax, OCOTP_TIMING_RELAX);
+ timing |= BF(strobe_read, OCOTP_TIMING_STROBE_READ);
+ timing |= BF(strobe_prog, OCOTP_TIMING_STROBE_PROG);
+
+ return timing;
+}
+
+static int vf610_ocotp_set_timing(void __iomem *base, int timing)
+{
+ writel(timing, base + OCOTP_TIMING);
+
+ return 0;
+}
+
+static int vf610_ocotp_write(void *context, const void *data, size_t count)
+{
+ return 0;
+}
+
+static int vf610_ocotp_read(void *context,
+ const void *offset, size_t reg_size,
+ void *val, size_t val_size)
+{
+ void __iomem *ocotp_base = context;
+ u32 *buf = val;
+ u32 reg;
+ int ret;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(valid_fuse_addr); i++) {
+ vf610_ocotp_set_timing(ocotp_base, ocotp_timing);
+ ret = vf610_ocotp_wait_busy(ocotp_base + OCOTP_CTRL_REG);
+ if (ret)
+ return ret;
+
+ reg = readl(ocotp_base + OCOTP_CTRL_REG);
+ reg &= ~OCOTP_CTRL_ADDR_MASK;
+ reg &= ~OCOTP_CTRL_WR_UNLOCK_MASK;
+ reg |= BF(valid_fuse_addr[i], OCOTP_CTRL_ADDR);
+ writel(reg, ocotp_base + OCOTP_CTRL_REG);
+
+ writel(OCOTP_READ_CTRL_READ_FUSE,
+ ocotp_base + OCOTP_READ_CTRL_REG);
+ ret = vf610_ocotp_wait_busy(ocotp_base + OCOTP_CTRL_REG);
+ if (ret)
+ return ret;
+
+ if (readl(ocotp_base) & OCOTP_CTRL_ERROR) {
+ pr_err("Error reading from fuse address %d\n",
+ valid_fuse_addr[i]);
+ writel(OCOTP_CTRL_ERROR, ocotp_base + OCOTP_CTRL_CLR);
+ }
+
+ *buf++ = readl(ocotp_base + OCOTP_READ_FUSE_DATA);
+ }
+
+ return 0;
+}
+
+static struct regmap_bus vf610_ocotp_bus = {
+ .read = vf610_ocotp_read,
+ .write = vf610_ocotp_write,
+ .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+ .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static struct regmap_config ocotp_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static struct nvmem_config ocotp_config = {
+ .name = "ocotp",
+ .owner = THIS_MODULE,
+};
+
+static const struct of_device_id ocotp_of_match[] = {
+ { .compatible = "fsl,vf610-ocotp",},
+ {/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, ocotp_of_match);
+
+static int vf610_ocotp_remove(struct platform_device *pdev)
+{
+ struct vf610_ocotp_dev *ocotp_dev = platform_get_drvdata(pdev);
+
+ return nvmem_unregister(ocotp_dev->nvmem);
+}
+
+static int vf610_ocotp_probe(struct platform_device *pdev)
+{
+ struct vf610_ocotp_dev *ocotp_dev;
+
+ ocotp_dev = devm_kzalloc(&pdev->dev,
+ sizeof(struct vf610_ocotp_dev), GFP_KERNEL);
+ if (!ocotp_dev)
+ return -ENOMEM;
+
+ ocotp_dev->dev = &pdev->dev;
+
+ ocotp_dev->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ocotp_dev->base = devm_ioremap_resource(ocotp_dev->dev, ocotp_dev->res);
+ if (IS_ERR(ocotp_dev->base))
+ return PTR_ERR(ocotp_dev->base);
+
+ ocotp_dev->clk = devm_clk_get(ocotp_dev->dev, "ocotp");
+ if (IS_ERR(ocotp_dev->clk)) {
+ dev_err(ocotp_dev->dev, "failed getting clock, err = %ld\n",
+ PTR_ERR(ocotp_dev->clk));
+ return PTR_ERR(ocotp_dev->clk);
+ }
+
+ ocotp_regmap_config.max_register = resource_size(ocotp_dev->res) - 1;
+
+ ocotp_dev->regmap = devm_regmap_init(ocotp_dev->dev,
+ &vf610_ocotp_bus, ocotp_dev->base, &ocotp_regmap_config);
+ if (IS_ERR(ocotp_dev->regmap)) {
+ dev_err(ocotp_dev->dev, "regmap init failed\n");
+ return PTR_ERR(ocotp_dev->regmap);
+ }
+ ocotp_config.dev = ocotp_dev->dev;
+
+ ocotp_dev->nvmem = nvmem_register(&ocotp_config);
+ if (IS_ERR(ocotp_dev->nvmem))
+ return PTR_ERR(ocotp_dev->nvmem);
+
+ platform_set_drvdata(pdev, ocotp_dev);
+
+ ocotp_timing = vf610_ocotp_calculate_timing(ocotp_dev);
+
+ return 0;
+}
+
+static struct platform_driver vf610_ocotp_driver = {
+ .probe = vf610_ocotp_probe,
+ .remove = vf610_ocotp_remove,
+ .driver = {
+ .name = "vf610-ocotp",
+ .of_match_table = ocotp_of_match,
+ },
+};
+module_platform_driver(vf610_ocotp_driver);
+MODULE_AUTHOR("Sanchayan Maity <sanchayan.maity@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Vybrid OCOTP driver");
+MODULE_LICENSE("GPL v2");
--
2.4.4
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