1*8caef1faSMartin Blumenstingl /* 2*8caef1faSMartin Blumenstingl * Amlogic Meson6, Meson8 and Meson8b eFuse Driver 3*8caef1faSMartin Blumenstingl * 4*8caef1faSMartin Blumenstingl * Copyright (c) 2017 Martin Blumenstingl <martin.blumenstingl@googlemail.com> 5*8caef1faSMartin Blumenstingl * 6*8caef1faSMartin Blumenstingl * This program is free software; you can redistribute it and/or modify it 7*8caef1faSMartin Blumenstingl * under the terms of version 2 of the GNU General Public License as 8*8caef1faSMartin Blumenstingl * published by the Free Software Foundation. 9*8caef1faSMartin Blumenstingl * 10*8caef1faSMartin Blumenstingl * This program is distributed in the hope that it will be useful, but WITHOUT 11*8caef1faSMartin Blumenstingl * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12*8caef1faSMartin Blumenstingl * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13*8caef1faSMartin Blumenstingl * more details. 14*8caef1faSMartin Blumenstingl */ 15*8caef1faSMartin Blumenstingl 16*8caef1faSMartin Blumenstingl #include <linux/bitfield.h> 17*8caef1faSMartin Blumenstingl #include <linux/bitops.h> 18*8caef1faSMartin Blumenstingl #include <linux/clk.h> 19*8caef1faSMartin Blumenstingl #include <linux/delay.h> 20*8caef1faSMartin Blumenstingl #include <linux/io.h> 21*8caef1faSMartin Blumenstingl #include <linux/iopoll.h> 22*8caef1faSMartin Blumenstingl #include <linux/module.h> 23*8caef1faSMartin Blumenstingl #include <linux/nvmem-provider.h> 24*8caef1faSMartin Blumenstingl #include <linux/of.h> 25*8caef1faSMartin Blumenstingl #include <linux/of_device.h> 26*8caef1faSMartin Blumenstingl #include <linux/platform_device.h> 27*8caef1faSMartin Blumenstingl #include <linux/sizes.h> 28*8caef1faSMartin Blumenstingl #include <linux/slab.h> 29*8caef1faSMartin Blumenstingl 30*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1 0x04 31*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_PD_ENABLE BIT(27) 32*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_RD_BUSY BIT(26) 33*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_RD_START BIT(25) 34*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE BIT(24) 35*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_BYTE_WR_DATA GENMASK(23, 16) 36*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_WR_BUSY BIT(14) 37*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_WR_START BIT(13) 38*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_AUTO_WR_ENABLE BIT(12) 39*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET BIT(11) 40*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK GENMASK(10, 0) 41*8caef1faSMartin Blumenstingl 42*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL2 0x08 43*8caef1faSMartin Blumenstingl 44*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL4 0x10 45*8caef1faSMartin Blumenstingl #define MESON_MX_EFUSE_CNTL4_ENCRYPT_ENABLE BIT(10) 46*8caef1faSMartin Blumenstingl 47*8caef1faSMartin Blumenstingl struct meson_mx_efuse_platform_data { 48*8caef1faSMartin Blumenstingl const char *name; 49*8caef1faSMartin Blumenstingl unsigned int word_size; 50*8caef1faSMartin Blumenstingl }; 51*8caef1faSMartin Blumenstingl 52*8caef1faSMartin Blumenstingl struct meson_mx_efuse { 53*8caef1faSMartin Blumenstingl void __iomem *base; 54*8caef1faSMartin Blumenstingl struct clk *core_clk; 55*8caef1faSMartin Blumenstingl struct nvmem_device *nvmem; 56*8caef1faSMartin Blumenstingl struct nvmem_config config; 57*8caef1faSMartin Blumenstingl }; 58*8caef1faSMartin Blumenstingl 59*8caef1faSMartin Blumenstingl static void meson_mx_efuse_mask_bits(struct meson_mx_efuse *efuse, u32 reg, 60*8caef1faSMartin Blumenstingl u32 mask, u32 set) 61*8caef1faSMartin Blumenstingl { 62*8caef1faSMartin Blumenstingl u32 data; 63*8caef1faSMartin Blumenstingl 64*8caef1faSMartin Blumenstingl data = readl(efuse->base + reg); 65*8caef1faSMartin Blumenstingl data &= ~mask; 66*8caef1faSMartin Blumenstingl data |= (set & mask); 67*8caef1faSMartin Blumenstingl 68*8caef1faSMartin Blumenstingl writel(data, efuse->base + reg); 69*8caef1faSMartin Blumenstingl } 70*8caef1faSMartin Blumenstingl 71*8caef1faSMartin Blumenstingl static int meson_mx_efuse_hw_enable(struct meson_mx_efuse *efuse) 72*8caef1faSMartin Blumenstingl { 73*8caef1faSMartin Blumenstingl int err; 74*8caef1faSMartin Blumenstingl 75*8caef1faSMartin Blumenstingl err = clk_prepare_enable(efuse->core_clk); 76*8caef1faSMartin Blumenstingl if (err) 77*8caef1faSMartin Blumenstingl return err; 78*8caef1faSMartin Blumenstingl 79*8caef1faSMartin Blumenstingl /* power up the efuse */ 80*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 81*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_PD_ENABLE, 0); 82*8caef1faSMartin Blumenstingl 83*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL4, 84*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL4_ENCRYPT_ENABLE, 0); 85*8caef1faSMartin Blumenstingl 86*8caef1faSMartin Blumenstingl return 0; 87*8caef1faSMartin Blumenstingl } 88*8caef1faSMartin Blumenstingl 89*8caef1faSMartin Blumenstingl static void meson_mx_efuse_hw_disable(struct meson_mx_efuse *efuse) 90*8caef1faSMartin Blumenstingl { 91*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 92*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_PD_ENABLE, 93*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_PD_ENABLE); 94*8caef1faSMartin Blumenstingl 95*8caef1faSMartin Blumenstingl clk_disable_unprepare(efuse->core_clk); 96*8caef1faSMartin Blumenstingl } 97*8caef1faSMartin Blumenstingl 98*8caef1faSMartin Blumenstingl static int meson_mx_efuse_read_addr(struct meson_mx_efuse *efuse, 99*8caef1faSMartin Blumenstingl unsigned int addr, u32 *value) 100*8caef1faSMartin Blumenstingl { 101*8caef1faSMartin Blumenstingl int err; 102*8caef1faSMartin Blumenstingl u32 regval; 103*8caef1faSMartin Blumenstingl 104*8caef1faSMartin Blumenstingl /* write the address to read */ 105*8caef1faSMartin Blumenstingl regval = FIELD_PREP(MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK, addr); 106*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 107*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_BYTE_ADDR_MASK, regval); 108*8caef1faSMartin Blumenstingl 109*8caef1faSMartin Blumenstingl /* inform the hardware that we changed the address */ 110*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 111*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET, 112*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET); 113*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 114*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_BYTE_ADDR_SET, 0); 115*8caef1faSMartin Blumenstingl 116*8caef1faSMartin Blumenstingl /* start the read process */ 117*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 118*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_START, 119*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_START); 120*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 121*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_START, 0); 122*8caef1faSMartin Blumenstingl 123*8caef1faSMartin Blumenstingl /* 124*8caef1faSMartin Blumenstingl * perform a dummy read to ensure that the HW has the RD_BUSY bit set 125*8caef1faSMartin Blumenstingl * when polling for the status below. 126*8caef1faSMartin Blumenstingl */ 127*8caef1faSMartin Blumenstingl readl(efuse->base + MESON_MX_EFUSE_CNTL1); 128*8caef1faSMartin Blumenstingl 129*8caef1faSMartin Blumenstingl err = readl_poll_timeout_atomic(efuse->base + MESON_MX_EFUSE_CNTL1, 130*8caef1faSMartin Blumenstingl regval, 131*8caef1faSMartin Blumenstingl (!(regval & MESON_MX_EFUSE_CNTL1_AUTO_RD_BUSY)), 132*8caef1faSMartin Blumenstingl 1, 1000); 133*8caef1faSMartin Blumenstingl if (err) { 134*8caef1faSMartin Blumenstingl dev_err(efuse->config.dev, 135*8caef1faSMartin Blumenstingl "Timeout while reading efuse address %u\n", addr); 136*8caef1faSMartin Blumenstingl return err; 137*8caef1faSMartin Blumenstingl } 138*8caef1faSMartin Blumenstingl 139*8caef1faSMartin Blumenstingl *value = readl(efuse->base + MESON_MX_EFUSE_CNTL2); 140*8caef1faSMartin Blumenstingl 141*8caef1faSMartin Blumenstingl return 0; 142*8caef1faSMartin Blumenstingl } 143*8caef1faSMartin Blumenstingl 144*8caef1faSMartin Blumenstingl static int meson_mx_efuse_read(void *context, unsigned int offset, 145*8caef1faSMartin Blumenstingl void *buf, size_t bytes) 146*8caef1faSMartin Blumenstingl { 147*8caef1faSMartin Blumenstingl struct meson_mx_efuse *efuse = context; 148*8caef1faSMartin Blumenstingl u32 tmp; 149*8caef1faSMartin Blumenstingl int err, i, addr; 150*8caef1faSMartin Blumenstingl 151*8caef1faSMartin Blumenstingl err = meson_mx_efuse_hw_enable(efuse); 152*8caef1faSMartin Blumenstingl if (err) 153*8caef1faSMartin Blumenstingl return err; 154*8caef1faSMartin Blumenstingl 155*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 156*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE, 157*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE); 158*8caef1faSMartin Blumenstingl 159*8caef1faSMartin Blumenstingl for (i = offset; i < offset + bytes; i += efuse->config.word_size) { 160*8caef1faSMartin Blumenstingl addr = i / efuse->config.word_size; 161*8caef1faSMartin Blumenstingl 162*8caef1faSMartin Blumenstingl err = meson_mx_efuse_read_addr(efuse, addr, &tmp); 163*8caef1faSMartin Blumenstingl if (err) 164*8caef1faSMartin Blumenstingl break; 165*8caef1faSMartin Blumenstingl 166*8caef1faSMartin Blumenstingl memcpy(buf + i, &tmp, efuse->config.word_size); 167*8caef1faSMartin Blumenstingl } 168*8caef1faSMartin Blumenstingl 169*8caef1faSMartin Blumenstingl meson_mx_efuse_mask_bits(efuse, MESON_MX_EFUSE_CNTL1, 170*8caef1faSMartin Blumenstingl MESON_MX_EFUSE_CNTL1_AUTO_RD_ENABLE, 0); 171*8caef1faSMartin Blumenstingl 172*8caef1faSMartin Blumenstingl meson_mx_efuse_hw_disable(efuse); 173*8caef1faSMartin Blumenstingl 174*8caef1faSMartin Blumenstingl return err; 175*8caef1faSMartin Blumenstingl } 176*8caef1faSMartin Blumenstingl 177*8caef1faSMartin Blumenstingl static const struct meson_mx_efuse_platform_data meson6_efuse_data = { 178*8caef1faSMartin Blumenstingl .name = "meson6-efuse", 179*8caef1faSMartin Blumenstingl .word_size = 1, 180*8caef1faSMartin Blumenstingl }; 181*8caef1faSMartin Blumenstingl 182*8caef1faSMartin Blumenstingl static const struct meson_mx_efuse_platform_data meson8_efuse_data = { 183*8caef1faSMartin Blumenstingl .name = "meson8-efuse", 184*8caef1faSMartin Blumenstingl .word_size = 4, 185*8caef1faSMartin Blumenstingl }; 186*8caef1faSMartin Blumenstingl 187*8caef1faSMartin Blumenstingl static const struct meson_mx_efuse_platform_data meson8b_efuse_data = { 188*8caef1faSMartin Blumenstingl .name = "meson8b-efuse", 189*8caef1faSMartin Blumenstingl .word_size = 4, 190*8caef1faSMartin Blumenstingl }; 191*8caef1faSMartin Blumenstingl 192*8caef1faSMartin Blumenstingl static const struct of_device_id meson_mx_efuse_match[] = { 193*8caef1faSMartin Blumenstingl { .compatible = "amlogic,meson6-efuse", .data = &meson6_efuse_data }, 194*8caef1faSMartin Blumenstingl { .compatible = "amlogic,meson8-efuse", .data = &meson8_efuse_data }, 195*8caef1faSMartin Blumenstingl { .compatible = "amlogic,meson8b-efuse", .data = &meson8b_efuse_data }, 196*8caef1faSMartin Blumenstingl { /* sentinel */ }, 197*8caef1faSMartin Blumenstingl }; 198*8caef1faSMartin Blumenstingl MODULE_DEVICE_TABLE(of, meson_mx_efuse_match); 199*8caef1faSMartin Blumenstingl 200*8caef1faSMartin Blumenstingl static int meson_mx_efuse_probe(struct platform_device *pdev) 201*8caef1faSMartin Blumenstingl { 202*8caef1faSMartin Blumenstingl const struct meson_mx_efuse_platform_data *drvdata; 203*8caef1faSMartin Blumenstingl struct meson_mx_efuse *efuse; 204*8caef1faSMartin Blumenstingl struct resource *res; 205*8caef1faSMartin Blumenstingl 206*8caef1faSMartin Blumenstingl drvdata = of_device_get_match_data(&pdev->dev); 207*8caef1faSMartin Blumenstingl if (!drvdata) 208*8caef1faSMartin Blumenstingl return -EINVAL; 209*8caef1faSMartin Blumenstingl 210*8caef1faSMartin Blumenstingl efuse = devm_kzalloc(&pdev->dev, sizeof(*efuse), GFP_KERNEL); 211*8caef1faSMartin Blumenstingl if (!efuse) 212*8caef1faSMartin Blumenstingl return -ENOMEM; 213*8caef1faSMartin Blumenstingl 214*8caef1faSMartin Blumenstingl res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 215*8caef1faSMartin Blumenstingl efuse->base = devm_ioremap_resource(&pdev->dev, res); 216*8caef1faSMartin Blumenstingl if (IS_ERR(efuse->base)) 217*8caef1faSMartin Blumenstingl return PTR_ERR(efuse->base); 218*8caef1faSMartin Blumenstingl 219*8caef1faSMartin Blumenstingl efuse->config.name = devm_kstrdup(&pdev->dev, drvdata->name, 220*8caef1faSMartin Blumenstingl GFP_KERNEL); 221*8caef1faSMartin Blumenstingl efuse->config.owner = THIS_MODULE; 222*8caef1faSMartin Blumenstingl efuse->config.dev = &pdev->dev; 223*8caef1faSMartin Blumenstingl efuse->config.priv = efuse; 224*8caef1faSMartin Blumenstingl efuse->config.stride = drvdata->word_size; 225*8caef1faSMartin Blumenstingl efuse->config.word_size = drvdata->word_size; 226*8caef1faSMartin Blumenstingl efuse->config.size = SZ_512; 227*8caef1faSMartin Blumenstingl efuse->config.read_only = true; 228*8caef1faSMartin Blumenstingl efuse->config.reg_read = meson_mx_efuse_read; 229*8caef1faSMartin Blumenstingl 230*8caef1faSMartin Blumenstingl efuse->core_clk = devm_clk_get(&pdev->dev, "core"); 231*8caef1faSMartin Blumenstingl if (IS_ERR(efuse->core_clk)) { 232*8caef1faSMartin Blumenstingl dev_err(&pdev->dev, "Failed to get core clock\n"); 233*8caef1faSMartin Blumenstingl return PTR_ERR(efuse->core_clk); 234*8caef1faSMartin Blumenstingl } 235*8caef1faSMartin Blumenstingl 236*8caef1faSMartin Blumenstingl efuse->nvmem = nvmem_register(&efuse->config); 237*8caef1faSMartin Blumenstingl if (IS_ERR(efuse->nvmem)) 238*8caef1faSMartin Blumenstingl return PTR_ERR(efuse->nvmem); 239*8caef1faSMartin Blumenstingl 240*8caef1faSMartin Blumenstingl platform_set_drvdata(pdev, efuse); 241*8caef1faSMartin Blumenstingl 242*8caef1faSMartin Blumenstingl return 0; 243*8caef1faSMartin Blumenstingl } 244*8caef1faSMartin Blumenstingl 245*8caef1faSMartin Blumenstingl static int meson_mx_efuse_remove(struct platform_device *pdev) 246*8caef1faSMartin Blumenstingl { 247*8caef1faSMartin Blumenstingl struct meson_mx_efuse *efuse = platform_get_drvdata(pdev); 248*8caef1faSMartin Blumenstingl 249*8caef1faSMartin Blumenstingl return nvmem_unregister(efuse->nvmem); 250*8caef1faSMartin Blumenstingl } 251*8caef1faSMartin Blumenstingl 252*8caef1faSMartin Blumenstingl static struct platform_driver meson_mx_efuse_driver = { 253*8caef1faSMartin Blumenstingl .probe = meson_mx_efuse_probe, 254*8caef1faSMartin Blumenstingl .remove = meson_mx_efuse_remove, 255*8caef1faSMartin Blumenstingl .driver = { 256*8caef1faSMartin Blumenstingl .name = "meson-mx-efuse", 257*8caef1faSMartin Blumenstingl .of_match_table = meson_mx_efuse_match, 258*8caef1faSMartin Blumenstingl }, 259*8caef1faSMartin Blumenstingl }; 260*8caef1faSMartin Blumenstingl 261*8caef1faSMartin Blumenstingl module_platform_driver(meson_mx_efuse_driver); 262*8caef1faSMartin Blumenstingl 263*8caef1faSMartin Blumenstingl MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>"); 264*8caef1faSMartin Blumenstingl MODULE_DESCRIPTION("Amlogic Meson MX eFuse NVMEM driver"); 265*8caef1faSMartin Blumenstingl MODULE_LICENSE("GPL v2"); 266