nvmem: mediatek: Add Mediatek EFUSE driver

Add Mediatek EFUSE driver to access hardware data like
thermal sensor calibration or HDMI impedance.

Signed-off-by: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 6ff1b50..5bd18cc 100644 (file)
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -45,6 +45,17 @@ config NVMEM_MXS_OCOTP
          This driver can also be built as a module. If so, the module
          will be called nvmem-mxs-ocotp.
 
+config MTK_EFUSE
+       tristate "Mediatek SoCs EFUSE support"
+       depends on ARCH_MEDIATEK || COMPILE_TEST
+       select REGMAP_MMIO
+       help
+         This is a driver to access hardware related data like sensor
+         calibration, HDMI impedance etc.
+
+         This driver can also be built as a module. If so, the module
+         will be called efuse-mtk.
+
 config QCOM_QFPROM
        tristate "QCOM QFPROM Support"
        depends on ARCH_QCOM || COMPILE_TEST

diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index c14a556..45ab1ae 100644 (file)
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -12,6 +12,8 @@ obj-$(CONFIG_NVMEM_LPC18XX_EEPROM)    += nvmem_lpc18xx_eeprom.o
 nvmem_lpc18xx_eeprom-y := lpc18xx_eeprom.o
 obj-$(CONFIG_NVMEM_MXS_OCOTP)  += nvmem-mxs-ocotp.o
 nvmem-mxs-ocotp-y              := mxs-ocotp.o
+obj-$(CONFIG_MTK_EFUSE)                += nvmem_mtk-efuse.o
+nvmem_mtk-efuse-y              := mtk-efuse.o
 obj-$(CONFIG_QCOM_QFPROM)      += nvmem_qfprom.o
 nvmem_qfprom-y                 := qfprom.o
 obj-$(CONFIG_ROCKCHIP_EFUSE)   += nvmem_rockchip_efuse.o

diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
new file mode 100644 (file)
index 0000000..7b35f5b
--- /dev/null
+++ b/drivers/nvmem/mtk-efuse.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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/device.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static struct regmap_config mtk_regmap_config = {
+       .reg_bits = 32,
+       .val_bits = 32,
+       .reg_stride = 4,
+};
+
+static int mtk_efuse_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct resource *res;
+       struct nvmem_device *nvmem;
+       struct nvmem_config *econfig;
+       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);
+
+       econfig = devm_kzalloc(dev, sizeof(*econfig), GFP_KERNEL);
+       if (!econfig)
+               return -ENOMEM;
+
+       mtk_regmap_config.max_register = resource_size(res) - 1;
+
+       regmap = devm_regmap_init_mmio(dev, base, &mtk_regmap_config);
+       if (IS_ERR(regmap)) {
+               dev_err(dev, "regmap init failed\n");
+               return PTR_ERR(regmap);
+       }
+
+       econfig->dev = dev;
+       econfig->owner = THIS_MODULE;
+       nvmem = nvmem_register(econfig);
+       if (IS_ERR(nvmem))
+               return PTR_ERR(nvmem);
+
+       platform_set_drvdata(pdev, nvmem);
+
+       return 0;
+}
+
+static int mtk_efuse_remove(struct platform_device *pdev)
+{
+       struct nvmem_device *nvmem = platform_get_drvdata(pdev);
+
+       return nvmem_unregister(nvmem);
+}
+
+static const struct of_device_id mtk_efuse_of_match[] = {
+       { .compatible = "mediatek,mt8173-efuse",},
+       { .compatible = "mediatek,efuse",},
+       {/* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
+
+static struct platform_driver mtk_efuse_driver = {
+       .probe = mtk_efuse_probe,
+       .remove = mtk_efuse_remove,
+       .driver = {
+               .name = "mediatek,efuse",
+               .of_match_table = mtk_efuse_of_match,
+       },
+};
+module_platform_driver(mtk_efuse_driver);
+MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
+MODULE_DESCRIPTION("Mediatek EFUSE driver");
+MODULE_LICENSE("GPL v2");