/* * Rockchip eFuse Driver * * Copyright (c) 2015 Rockchip Electronics Co. Ltd. * Author: Caesar Wang * * 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 #include #include #include #include #include #include #include #include #include #define RK3288_A_SHIFT 6 #define RK3288_A_MASK 0x3ff #define RK3288_PGENB BIT(3) #define RK3288_LOAD BIT(2) #define RK3288_STROBE BIT(1) #define RK3288_CSB BIT(0) #define RK3399_A_SHIFT 16 #define RK3399_A_MASK 0x3ff #define RK3399_NBYTES 4 #define RK3399_STROBSFTSEL BIT(9) #define RK3399_RSB BIT(7) #define RK3399_PD BIT(5) #define RK3399_PGENB BIT(3) #define RK3399_LOAD BIT(2) #define RK3399_STROBE BIT(1) #define RK3399_CSB BIT(0) #define REG_EFUSE_CTRL 0x0000 #define REG_EFUSE_DOUT 0x0004 struct rockchip_efuse_chip { struct device *dev; void __iomem *base; struct clk *clk; }; static int rockchip_rk3288_efuse_read(void *context, unsigned int offset, void *val, size_t bytes) { struct rockchip_efuse_chip *efuse = context; u8 *buf = val; int ret; ret = clk_prepare_enable(efuse->clk); if (ret < 0) { dev_err(efuse->dev, "failed to prepare/enable efuse clk\n"); return ret; } writel(RK3288_LOAD | RK3288_PGENB, efuse->base + REG_EFUSE_CTRL); udelay(1); while (bytes--) { writel(readl(efuse->base + REG_EFUSE_CTRL) & (~(RK3288_A_MASK << RK3288_A_SHIFT)), efuse->base + REG_EFUSE_CTRL); writel(readl(efuse->base + REG_EFUSE_CTRL) | ((offset++ & RK3288_A_MASK) << RK3288_A_SHIFT), efuse->base + REG_EFUSE_CTRL); udelay(1); writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3288_STROBE, efuse->base + REG_EFUSE_CTRL); udelay(1); *buf++ = readb(efuse->base + REG_EFUSE_DOUT); writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3288_STROBE), efuse->base + REG_EFUSE_CTRL); udelay(1); } /* Switch to standby mode */ writel(RK3288_PGENB | RK3288_CSB, efuse->base + REG_EFUSE_CTRL); clk_disable_unprepare(efuse->clk); return 0; } static int rockchip_rk3399_efuse_read(void *context, unsigned int offset, void *val, size_t bytes) { struct rockchip_efuse_chip *efuse = context; unsigned int addr_start, addr_end, addr_offset, addr_len; u32 out_value; u8 *buf; int ret, i = 0; ret = clk_prepare_enable(efuse->clk); if (ret < 0) { dev_err(efuse->dev, "failed to prepare/enable efuse clk\n"); return ret; } addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES; addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES; addr_offset = offset % RK3399_NBYTES; addr_len = addr_end - addr_start; buf = kzalloc(sizeof(*buf) * addr_len * RK3399_NBYTES, GFP_KERNEL); if (!buf) { clk_disable_unprepare(efuse->clk); return -ENOMEM; } writel(RK3399_LOAD | RK3399_PGENB | RK3399_STROBSFTSEL | RK3399_RSB, efuse->base + REG_EFUSE_CTRL); udelay(1); while (addr_len--) { writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3399_STROBE | ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT), efuse->base + REG_EFUSE_CTRL); udelay(1); out_value = readl(efuse->base + REG_EFUSE_DOUT); writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3399_STROBE), efuse->base + REG_EFUSE_CTRL); udelay(1); memcpy(&buf[i], &out_value, RK3399_NBYTES); i += RK3399_NBYTES; } /* Switch to standby mode */ writel(RK3399_PD | RK3399_CSB, efuse->base + REG_EFUSE_CTRL); memcpy(val, buf + addr_offset, bytes); kfree(buf); clk_disable_unprepare(efuse->clk); return 0; } static struct nvmem_config econfig = { .name = "rockchip-efuse", .owner = THIS_MODULE, .stride = 1, .word_size = 1, .read_only = true, }; static const struct of_device_id rockchip_efuse_match[] = { /* deprecated but kept around for dts binding compatibility */ { .compatible = "rockchip,rockchip-efuse", .data = (void *)&rockchip_rk3288_efuse_read, }, { .compatible = "rockchip,rk3066a-efuse", .data = (void *)&rockchip_rk3288_efuse_read, }, { .compatible = "rockchip,rk3188-efuse", .data = (void *)&rockchip_rk3288_efuse_read, }, { .compatible = "rockchip,rk3288-efuse", .data = (void *)&rockchip_rk3288_efuse_read, }, { .compatible = "rockchip,rk3399-efuse", .data = (void *)&rockchip_rk3399_efuse_read, }, { /* sentinel */}, }; MODULE_DEVICE_TABLE(of, rockchip_efuse_match); static int rockchip_efuse_probe(struct platform_device *pdev) { struct resource *res; struct nvmem_device *nvmem; struct rockchip_efuse_chip *efuse; const struct of_device_id *match; struct device *dev = &pdev->dev; match = of_match_device(dev->driver->of_match_table, dev); if (!match || !match->data) { dev_err(dev, "failed to get match data\n"); return -EINVAL; } efuse = devm_kzalloc(&pdev->dev, sizeof(struct rockchip_efuse_chip), GFP_KERNEL); if (!efuse) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); efuse->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(efuse->base)) return PTR_ERR(efuse->base); efuse->clk = devm_clk_get(&pdev->dev, "pclk_efuse"); if (IS_ERR(efuse->clk)) return PTR_ERR(efuse->clk); efuse->dev = &pdev->dev; econfig.size = resource_size(res); econfig.reg_read = match->data; econfig.priv = efuse; econfig.dev = efuse->dev; nvmem = nvmem_register(&econfig); if (IS_ERR(nvmem)) return PTR_ERR(nvmem); platform_set_drvdata(pdev, nvmem); return 0; } static 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");