1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Simulate an I2C real time clock 4 * 5 * Copyright (c) 2015 Google, Inc 6 * Written by Simon Glass <sjg@chromium.org> 7 */ 8 9 /* 10 * This is a test driver. It starts off with the current time of the machine, 11 * but also supports setting the time, using an offset from the current 12 * clock. This driver is only intended for testing, not accurate 13 * time-keeping. It does not change the system time. 14 */ 15 16 #include <common.h> 17 #include <dm.h> 18 #include <i2c.h> 19 #include <os.h> 20 #include <rtc.h> 21 #include <asm/rtc.h> 22 #include <asm/test.h> 23 24 #ifdef DEBUG 25 #define debug_buffer print_buffer 26 #else 27 #define debug_buffer(x, ...) 28 #endif 29 30 /** 31 * struct sandbox_i2c_rtc_plat_data - platform data for the RTC 32 * 33 * @base_time: Base system time when RTC device was bound 34 * @offset: RTC offset from current system time 35 * @use_system_time: true to use system time, false to use @base_time 36 * @reg: Register values 37 */ 38 struct sandbox_i2c_rtc_plat_data { 39 long base_time; 40 long offset; 41 bool use_system_time; 42 u8 reg[REG_COUNT]; 43 }; 44 45 struct sandbox_i2c_rtc { 46 unsigned int offset_secs; 47 }; 48 49 long sandbox_i2c_rtc_set_offset(struct udevice *dev, bool use_system_time, 50 int offset) 51 { 52 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev); 53 long old_offset; 54 55 old_offset = plat->offset; 56 plat->use_system_time = use_system_time; 57 if (offset != -1) 58 plat->offset = offset; 59 60 return old_offset; 61 } 62 63 long sandbox_i2c_rtc_get_set_base_time(struct udevice *dev, long base_time) 64 { 65 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev); 66 long old_base_time; 67 68 old_base_time = plat->base_time; 69 if (base_time != -1) 70 plat->base_time = base_time; 71 72 return old_base_time; 73 } 74 75 static void reset_time(struct udevice *dev) 76 { 77 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev); 78 struct rtc_time now; 79 80 os_localtime(&now); 81 plat->base_time = rtc_mktime(&now); 82 plat->offset = 0; 83 plat->use_system_time = true; 84 } 85 86 static int sandbox_i2c_rtc_get(struct udevice *dev, struct rtc_time *time) 87 { 88 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev); 89 struct rtc_time tm_now; 90 long now; 91 92 if (plat->use_system_time) { 93 os_localtime(&tm_now); 94 now = rtc_mktime(&tm_now); 95 } else { 96 now = plat->base_time; 97 } 98 99 return rtc_to_tm(now + plat->offset, time); 100 } 101 102 static int sandbox_i2c_rtc_set(struct udevice *dev, const struct rtc_time *time) 103 { 104 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(dev); 105 struct rtc_time tm_now; 106 long now; 107 108 if (plat->use_system_time) { 109 os_localtime(&tm_now); 110 now = rtc_mktime(&tm_now); 111 } else { 112 now = plat->base_time; 113 } 114 plat->offset = rtc_mktime(time) - now; 115 116 return 0; 117 } 118 119 /* Update the current time in the registers */ 120 static int sandbox_i2c_rtc_prepare_read(struct udevice *emul) 121 { 122 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul); 123 struct rtc_time time; 124 int ret; 125 126 ret = sandbox_i2c_rtc_get(emul, &time); 127 if (ret) 128 return ret; 129 130 plat->reg[REG_SEC] = time.tm_sec; 131 plat->reg[REG_MIN] = time.tm_min; 132 plat->reg[REG_HOUR] = time.tm_hour; 133 plat->reg[REG_MDAY] = time.tm_mday; 134 plat->reg[REG_MON] = time.tm_mon; 135 plat->reg[REG_YEAR] = time.tm_year - 1900; 136 plat->reg[REG_WDAY] = time.tm_wday; 137 138 return 0; 139 } 140 141 static int sandbox_i2c_rtc_complete_write(struct udevice *emul) 142 { 143 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul); 144 struct rtc_time time; 145 int ret; 146 147 time.tm_sec = plat->reg[REG_SEC]; 148 time.tm_min = plat->reg[REG_MIN]; 149 time.tm_hour = plat->reg[REG_HOUR]; 150 time.tm_mday = plat->reg[REG_MDAY]; 151 time.tm_mon = plat->reg[REG_MON]; 152 time.tm_year = plat->reg[REG_YEAR] + 1900; 153 time.tm_wday = plat->reg[REG_WDAY]; 154 155 ret = sandbox_i2c_rtc_set(emul, &time); 156 if (ret) 157 return ret; 158 159 return 0; 160 } 161 162 static int sandbox_i2c_rtc_xfer(struct udevice *emul, struct i2c_msg *msg, 163 int nmsgs) 164 { 165 struct sandbox_i2c_rtc_plat_data *plat = dev_get_platdata(emul); 166 uint offset = 0; 167 int ret; 168 169 debug("\n%s\n", __func__); 170 ret = sandbox_i2c_rtc_prepare_read(emul); 171 if (ret) 172 return ret; 173 for (; nmsgs > 0; nmsgs--, msg++) { 174 int len; 175 u8 *ptr; 176 177 len = msg->len; 178 debug(" %s: msg->len=%d", 179 msg->flags & I2C_M_RD ? "read" : "write", 180 msg->len); 181 if (msg->flags & I2C_M_RD) { 182 debug(", offset %x, len %x: ", offset, len); 183 184 /* Read the register */ 185 memcpy(msg->buf, plat->reg + offset, len); 186 memset(msg->buf + len, '\xff', msg->len - len); 187 debug_buffer(0, msg->buf, 1, msg->len, 0); 188 } else if (len >= 1) { 189 ptr = msg->buf; 190 offset = *ptr++ & (REG_COUNT - 1); 191 len--; 192 debug(", set offset %x: ", offset); 193 debug_buffer(0, msg->buf, 1, msg->len, 0); 194 195 /* Write the register */ 196 memcpy(plat->reg + offset, ptr, len); 197 if (offset == REG_RESET) 198 reset_time(emul); 199 } 200 } 201 ret = sandbox_i2c_rtc_complete_write(emul); 202 if (ret) 203 return ret; 204 205 return 0; 206 } 207 208 struct dm_i2c_ops sandbox_i2c_rtc_emul_ops = { 209 .xfer = sandbox_i2c_rtc_xfer, 210 }; 211 212 static int sandbox_i2c_rtc_bind(struct udevice *dev) 213 { 214 reset_time(dev); 215 216 return 0; 217 } 218 219 static const struct udevice_id sandbox_i2c_rtc_ids[] = { 220 { .compatible = "sandbox,i2c-rtc" }, 221 { } 222 }; 223 224 U_BOOT_DRIVER(sandbox_i2c_rtc_emul) = { 225 .name = "sandbox_i2c_rtc_emul", 226 .id = UCLASS_I2C_EMUL, 227 .of_match = sandbox_i2c_rtc_ids, 228 .bind = sandbox_i2c_rtc_bind, 229 .priv_auto_alloc_size = sizeof(struct sandbox_i2c_rtc), 230 .platdata_auto_alloc_size = sizeof(struct sandbox_i2c_rtc_plat_data), 231 .ops = &sandbox_i2c_rtc_emul_ops, 232 }; 233