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/of_device.h> 13 #include <linux/mtd/map.h> 14 #include <linux/mfd/syscon.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 if (!ebi_base) 97 return -ENODEV; 98 99 /* Clear VPP and write protection bits */ 100 ret = regmap_write(syscon_regmap, 101 INTEGRATOR_SC_CTRLC_OFFSET, 102 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 103 if (ret) 104 dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n"); 105 106 /* Unlock the EBI */ 107 writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); 108 109 /* Enable write cycles on the EBI, CSR1 (flash) */ 110 val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); 111 val |= INTEGRATOR_EBI_WRITE_ENABLE; 112 writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); 113 114 /* Lock the EBI again */ 115 writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); 116 iounmap(ebi_base); 117 118 return 0; 119 } 120 121 static void ap_flash_set_vpp(struct map_info *map, int on) 122 { 123 int ret; 124 125 if (on) { 126 ret = regmap_write(syscon_regmap, 127 INTEGRATOR_SC_CTRLS_OFFSET, 128 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 129 if (ret) 130 pr_err("error enabling AP VPP\n"); 131 } else { 132 ret = regmap_write(syscon_regmap, 133 INTEGRATOR_SC_CTRLC_OFFSET, 134 INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); 135 if (ret) 136 pr_err("error disabling AP VPP\n"); 137 } 138 } 139 140 /* 141 * Flash protection handling for the Integrator/CP 142 */ 143 144 #define INTCP_FLASHPROG_OFFSET 0x04 145 #define CINTEGRATOR_FLVPPEN BIT(0) 146 #define CINTEGRATOR_FLWREN BIT(1) 147 #define CINTEGRATOR_FLMASK BIT(0)|BIT(1) 148 149 static void cp_flash_set_vpp(struct map_info *map, int on) 150 { 151 int ret; 152 153 if (on) { 154 ret = regmap_update_bits(syscon_regmap, 155 INTCP_FLASHPROG_OFFSET, 156 CINTEGRATOR_FLMASK, 157 CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN); 158 if (ret) 159 pr_err("error setting CP VPP\n"); 160 } else { 161 ret = regmap_update_bits(syscon_regmap, 162 INTCP_FLASHPROG_OFFSET, 163 CINTEGRATOR_FLMASK, 164 0); 165 if (ret) 166 pr_err("error setting CP VPP\n"); 167 } 168 } 169 170 /* 171 * Flash protection handling for the Versatiles and RealViews 172 */ 173 174 #define VERSATILE_SYS_FLASH_OFFSET 0x4C 175 176 static void versatile_flash_set_vpp(struct map_info *map, int on) 177 { 178 int ret; 179 180 ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET, 181 0x01, !!on); 182 if (ret) 183 pr_err("error setting Versatile VPP\n"); 184 } 185 186 int of_flash_probe_versatile(struct platform_device *pdev, 187 struct device_node *np, 188 struct map_info *map) 189 { 190 struct device_node *sysnp; 191 const struct of_device_id *devid; 192 struct regmap *rmap; 193 static enum versatile_flashprot versatile_flashprot; 194 int ret; 195 196 /* Not all flash chips use this protection line */ 197 if (!of_device_is_compatible(np, "arm,versatile-flash")) 198 return 0; 199 200 /* For first chip probed, look up the syscon regmap */ 201 if (!syscon_regmap) { 202 sysnp = of_find_matching_node_and_match(NULL, 203 syscon_match, 204 &devid); 205 if (!sysnp) 206 return -ENODEV; 207 208 versatile_flashprot = (enum versatile_flashprot)devid->data; 209 rmap = syscon_node_to_regmap(sysnp); 210 if (IS_ERR(rmap)) 211 return PTR_ERR(rmap); 212 213 syscon_regmap = rmap; 214 } 215 216 switch (versatile_flashprot) { 217 case INTEGRATOR_AP_FLASHPROT: 218 ret = ap_flash_init(pdev); 219 if (ret) 220 return ret; 221 map->set_vpp = ap_flash_set_vpp; 222 dev_info(&pdev->dev, "Integrator/AP flash protection\n"); 223 break; 224 case INTEGRATOR_CP_FLASHPROT: 225 map->set_vpp = cp_flash_set_vpp; 226 dev_info(&pdev->dev, "Integrator/CP flash protection\n"); 227 break; 228 case VERSATILE_FLASHPROT: 229 case REALVIEW_FLASHPROT: 230 map->set_vpp = versatile_flash_set_vpp; 231 dev_info(&pdev->dev, "versatile/realview flash protection\n"); 232 break; 233 default: 234 dev_info(&pdev->dev, "device marked as Versatile flash " 235 "but no system controller was found\n"); 236 break; 237 } 238 239 return 0; 240 } 241