1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Versatile OF physmap driver add-on 4 * 5 * Copyright (c) 2016, Linaro Limited 6 * Author: Linus Walleij <linus.walleij@linaro.org> 7 */ 8 #include <linux/export.h> 9 #include <linux/io.h> 10 #include <linux/of.h> 11 #include <linux/of_address.h> 12 #include <linux/mtd/map.h> 13 #include <linux/mfd/syscon.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 #include <linux/bitops.h> 17 #include "physmap-versatile.h" 18 19 static struct regmap *syscon_regmap; 20 21 enum versatile_flashprot { 22 INTEGRATOR_AP_FLASHPROT, 23 INTEGRATOR_CP_FLASHPROT, 24 VERSATILE_FLASHPROT, 25 REALVIEW_FLASHPROT, 26 }; 27 28 static const struct of_device_id syscon_match[] = { 29 { 30 .compatible = "arm,integrator-ap-syscon", 31 .data = (void *)INTEGRATOR_AP_FLASHPROT, 32 }, 33 { 34 .compatible = "arm,integrator-cp-syscon", 35 .data = (void *)INTEGRATOR_CP_FLASHPROT, 36 }, 37 { 38 .compatible = "arm,core-module-versatile", 39 .data = (void *)VERSATILE_FLASHPROT, 40 }, 41 { 42 .compatible = "arm,realview-eb-syscon", 43 .data = (void *)REALVIEW_FLASHPROT, 44 }, 45 { 46 .compatible = "arm,realview-pb1176-syscon", 47 .data = (void *)REALVIEW_FLASHPROT, 48 }, 49 { 50 .compatible = "arm,realview-pb11mp-syscon", 51 .data = (void *)REALVIEW_FLASHPROT, 52 }, 53 { 54 .compatible = "arm,realview-pba8-syscon", 55 .data = (void *)REALVIEW_FLASHPROT, 56 }, 57 { 58 .compatible = "arm,realview-pbx-syscon", 59 .data = (void *)REALVIEW_FLASHPROT, 60 }, 61 {}, 62 }; 63 64 /* 65 * Flash protection handling for the Integrator/AP 66 */ 67 #define INTEGRATOR_SC_CTRLS_OFFSET 0x08 68 #define INTEGRATOR_SC_CTRLC_OFFSET 0x0C 69 #define INTEGRATOR_SC_CTRL_FLVPPEN BIT(1) 70 #define INTEGRATOR_SC_CTRL_FLWP BIT(2) 71 72 #define INTEGRATOR_EBI_CSR1_OFFSET 0x04 73 /* The manual says bit 2, the code says bit 3, trust the code */ 74 #define INTEGRATOR_EBI_WRITE_ENABLE BIT(3) 75 #define INTEGRATOR_EBI_LOCK_OFFSET 0x20 76 #define INTEGRATOR_EBI_LOCK_VAL 0xA05F 77 78 static const struct of_device_id ebi_match[] = { 79 { .compatible = "arm,external-bus-interface"}, 80 { }, 81 }; 82 83 static int ap_flash_init(struct platform_device *pdev) 84 { 85 struct device_node *ebi; 86 void __iomem *ebi_base; 87 u32 val; 88 int ret; 89 90 /* Look up the EBI */ 91 ebi = of_find_matching_node(NULL, ebi_match); 92 if (!ebi) { 93 return -ENODEV; 94 } 95 ebi_base = of_iomap(ebi, 0); 96 of_node_put(ebi); 97 if (!ebi_base) 98 return -ENODEV; 99 100 /* Clear VPP and write protection bits */ 101 ret = regmap_write(syscon_regmap, 102 INTEGRATOR_SC_CTRLC_OFFSET, 103 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 104 if (ret) 105 dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n"); 106 107 /* Unlock the EBI */ 108 writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); 109 110 /* Enable write cycles on the EBI, CSR1 (flash) */ 111 val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); 112 val |= INTEGRATOR_EBI_WRITE_ENABLE; 113 writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); 114 115 /* Lock the EBI again */ 116 writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); 117 iounmap(ebi_base); 118 119 return 0; 120 } 121 122 static void ap_flash_set_vpp(struct map_info *map, int on) 123 { 124 int ret; 125 126 if (on) { 127 ret = regmap_write(syscon_regmap, 128 INTEGRATOR_SC_CTRLS_OFFSET, 129 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 130 if (ret) 131 pr_err("error enabling AP VPP\n"); 132 } else { 133 ret = regmap_write(syscon_regmap, 134 INTEGRATOR_SC_CTRLC_OFFSET, 135 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 136 if (ret) 137 pr_err("error disabling AP VPP\n"); 138 } 139 } 140 141 /* 142 * Flash protection handling for the Integrator/CP 143 */ 144 145 #define INTCP_FLASHPROG_OFFSET 0x04 146 #define CINTEGRATOR_FLVPPEN BIT(0) 147 #define CINTEGRATOR_FLWREN BIT(1) 148 #define CINTEGRATOR_FLMASK BIT(0)|BIT(1) 149 150 static void cp_flash_set_vpp(struct map_info *map, int on) 151 { 152 int ret; 153 154 if (on) { 155 ret = regmap_update_bits(syscon_regmap, 156 INTCP_FLASHPROG_OFFSET, 157 CINTEGRATOR_FLMASK, 158 CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN); 159 if (ret) 160 pr_err("error setting CP VPP\n"); 161 } else { 162 ret = regmap_update_bits(syscon_regmap, 163 INTCP_FLASHPROG_OFFSET, 164 CINTEGRATOR_FLMASK, 165 0); 166 if (ret) 167 pr_err("error setting CP VPP\n"); 168 } 169 } 170 171 /* 172 * Flash protection handling for the Versatiles and RealViews 173 */ 174 175 #define VERSATILE_SYS_FLASH_OFFSET 0x4C 176 177 static void versatile_flash_set_vpp(struct map_info *map, int on) 178 { 179 int ret; 180 181 ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET, 182 0x01, !!on); 183 if (ret) 184 pr_err("error setting Versatile VPP\n"); 185 } 186 187 int of_flash_probe_versatile(struct platform_device *pdev, 188 struct device_node *np, 189 struct map_info *map) 190 { 191 struct device_node *sysnp; 192 const struct of_device_id *devid; 193 struct regmap *rmap; 194 static enum versatile_flashprot versatile_flashprot; 195 int ret; 196 197 /* Not all flash chips use this protection line */ 198 if (!of_device_is_compatible(np, "arm,versatile-flash")) 199 return 0; 200 201 /* For first chip probed, look up the syscon regmap */ 202 if (!syscon_regmap) { 203 sysnp = of_find_matching_node_and_match(NULL, 204 syscon_match, 205 &devid); 206 if (!sysnp) 207 return -ENODEV; 208 209 versatile_flashprot = (uintptr_t)devid->data; 210 rmap = syscon_node_to_regmap(sysnp); 211 of_node_put(sysnp); 212 if (IS_ERR(rmap)) 213 return PTR_ERR(rmap); 214 215 syscon_regmap = rmap; 216 } 217 218 switch (versatile_flashprot) { 219 case INTEGRATOR_AP_FLASHPROT: 220 ret = ap_flash_init(pdev); 221 if (ret) 222 return ret; 223 map->set_vpp = ap_flash_set_vpp; 224 dev_info(&pdev->dev, "Integrator/AP flash protection\n"); 225 break; 226 case INTEGRATOR_CP_FLASHPROT: 227 map->set_vpp = cp_flash_set_vpp; 228 dev_info(&pdev->dev, "Integrator/CP flash protection\n"); 229 break; 230 case VERSATILE_FLASHPROT: 231 case REALVIEW_FLASHPROT: 232 map->set_vpp = versatile_flash_set_vpp; 233 dev_info(&pdev->dev, "versatile/realview flash protection\n"); 234 break; 235 default: 236 dev_info(&pdev->dev, "device marked as Versatile flash " 237 "but no system controller was found\n"); 238 break; 239 } 240 241 return 0; 242 } 243