Vipin KUMAR | fc9589f | 2010-01-15 19:15:44 +0530 | [diff] [blame] | 1 | /* |
| 2 | * (C) Copyright 2009 |
| 3 | * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com. |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
| 24 | #include <common.h> |
| 25 | #include <asm/io.h> |
| 26 | #include <asm/arch/hardware.h> |
| 27 | #include <asm/arch/spr_i2c.h> |
| 28 | |
| 29 | static struct i2c_regs *const i2c_regs_p = |
| 30 | (struct i2c_regs *)CONFIG_SYS_I2C_BASE; |
| 31 | |
| 32 | /* |
| 33 | * set_speed - Set the i2c speed mode (standard, high, fast) |
| 34 | * @i2c_spd: required i2c speed mode |
| 35 | * |
| 36 | * Set the i2c speed mode (standard, high, fast) |
| 37 | */ |
| 38 | static void set_speed(int i2c_spd) |
| 39 | { |
| 40 | unsigned int cntl; |
| 41 | unsigned int hcnt, lcnt; |
| 42 | unsigned int high, low; |
| 43 | |
| 44 | cntl = (readl(&i2c_regs_p->ic_con) & (~IC_CON_SPD_MSK)); |
| 45 | |
| 46 | switch (i2c_spd) { |
| 47 | case IC_SPEED_MODE_MAX: |
| 48 | cntl |= IC_CON_SPD_HS; |
| 49 | high = MIN_HS_SCL_HIGHTIME; |
| 50 | low = MIN_HS_SCL_LOWTIME; |
| 51 | break; |
| 52 | |
| 53 | case IC_SPEED_MODE_STANDARD: |
| 54 | cntl |= IC_CON_SPD_SS; |
| 55 | high = MIN_SS_SCL_HIGHTIME; |
| 56 | low = MIN_SS_SCL_LOWTIME; |
| 57 | break; |
| 58 | |
| 59 | case IC_SPEED_MODE_FAST: |
| 60 | default: |
| 61 | cntl |= IC_CON_SPD_FS; |
| 62 | high = MIN_FS_SCL_HIGHTIME; |
| 63 | low = MIN_FS_SCL_LOWTIME; |
| 64 | break; |
| 65 | } |
| 66 | |
| 67 | writel(cntl, &i2c_regs_p->ic_con); |
| 68 | |
| 69 | hcnt = (IC_CLK * high) / NANO_TO_MICRO; |
| 70 | writel(hcnt, &i2c_regs_p->ic_fs_scl_hcnt); |
| 71 | |
| 72 | lcnt = (IC_CLK * low) / NANO_TO_MICRO; |
| 73 | writel(lcnt, &i2c_regs_p->ic_fs_scl_lcnt); |
| 74 | } |
| 75 | |
| 76 | /* |
| 77 | * i2c_set_bus_speed - Set the i2c speed |
| 78 | * @speed: required i2c speed |
| 79 | * |
| 80 | * Set the i2c speed. |
| 81 | */ |
| 82 | void i2c_set_bus_speed(int speed) |
| 83 | { |
| 84 | if (speed >= I2C_MAX_SPEED) |
| 85 | set_speed(IC_SPEED_MODE_MAX); |
| 86 | else if (speed >= I2C_FAST_SPEED) |
| 87 | set_speed(IC_SPEED_MODE_FAST); |
| 88 | else |
| 89 | set_speed(IC_SPEED_MODE_STANDARD); |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * i2c_get_bus_speed - Gets the i2c speed |
| 94 | * |
| 95 | * Gets the i2c speed. |
| 96 | */ |
| 97 | int i2c_get_bus_speed(void) |
| 98 | { |
| 99 | u32 cntl; |
| 100 | |
| 101 | cntl = (readl(&i2c_regs_p->ic_con) & IC_CON_SPD_MSK); |
| 102 | |
| 103 | if (cntl == IC_CON_SPD_HS) |
| 104 | return I2C_MAX_SPEED; |
| 105 | else if (cntl == IC_CON_SPD_FS) |
| 106 | return I2C_FAST_SPEED; |
| 107 | else if (cntl == IC_CON_SPD_SS) |
| 108 | return I2C_STANDARD_SPEED; |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * i2c_init - Init function |
| 115 | * @speed: required i2c speed |
| 116 | * @slaveadd: slave address for the spear device |
| 117 | * |
| 118 | * Initialization function. |
| 119 | */ |
| 120 | void i2c_init(int speed, int slaveadd) |
| 121 | { |
| 122 | unsigned int enbl; |
| 123 | |
| 124 | /* Disable i2c */ |
| 125 | enbl = readl(&i2c_regs_p->ic_enable); |
| 126 | enbl &= ~IC_ENABLE_0B; |
| 127 | writel(enbl, &i2c_regs_p->ic_enable); |
| 128 | |
| 129 | writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_regs_p->ic_con); |
| 130 | writel(IC_RX_TL, &i2c_regs_p->ic_rx_tl); |
| 131 | writel(IC_TX_TL, &i2c_regs_p->ic_tx_tl); |
| 132 | i2c_set_bus_speed(speed); |
| 133 | writel(IC_STOP_DET, &i2c_regs_p->ic_intr_mask); |
| 134 | writel(slaveadd, &i2c_regs_p->ic_sar); |
| 135 | |
| 136 | /* Enable i2c */ |
| 137 | enbl = readl(&i2c_regs_p->ic_enable); |
| 138 | enbl |= IC_ENABLE_0B; |
| 139 | writel(enbl, &i2c_regs_p->ic_enable); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * i2c_setaddress - Sets the target slave address |
| 144 | * @i2c_addr: target i2c address |
| 145 | * |
| 146 | * Sets the target slave address. |
| 147 | */ |
| 148 | static void i2c_setaddress(unsigned int i2c_addr) |
| 149 | { |
| 150 | writel(i2c_addr, &i2c_regs_p->ic_tar); |
| 151 | } |
| 152 | |
| 153 | /* |
| 154 | * i2c_flush_rxfifo - Flushes the i2c RX FIFO |
| 155 | * |
| 156 | * Flushes the i2c RX FIFO |
| 157 | */ |
| 158 | static void i2c_flush_rxfifo(void) |
| 159 | { |
| 160 | while (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) |
| 161 | readl(&i2c_regs_p->ic_cmd_data); |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * i2c_wait_for_bb - Waits for bus busy |
| 166 | * |
| 167 | * Waits for bus busy |
| 168 | */ |
| 169 | static int i2c_wait_for_bb(void) |
| 170 | { |
| 171 | unsigned long start_time_bb = get_timer(0); |
| 172 | |
| 173 | while ((readl(&i2c_regs_p->ic_status) & IC_STATUS_MA) || |
| 174 | !(readl(&i2c_regs_p->ic_status) & IC_STATUS_TFE)) { |
| 175 | |
| 176 | /* Evaluate timeout */ |
| 177 | if (get_timer(start_time_bb) > (unsigned long)(I2C_BYTE_TO_BB)) |
| 178 | return 1; |
| 179 | } |
| 180 | |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | /* check parameters for i2c_read and i2c_write */ |
| 185 | static int check_params(uint addr, int alen, uchar *buffer, int len) |
| 186 | { |
| 187 | if (buffer == NULL) { |
| 188 | printf("Buffer is invalid\n"); |
| 189 | return 1; |
| 190 | } |
| 191 | |
| 192 | if (alen > 1) { |
| 193 | printf("addr len %d not supported\n", alen); |
| 194 | return 1; |
| 195 | } |
| 196 | |
| 197 | if (addr + len > 256) { |
| 198 | printf("address out of range\n"); |
| 199 | return 1; |
| 200 | } |
| 201 | |
| 202 | return 0; |
| 203 | } |
| 204 | |
| 205 | static int i2c_xfer_init(uchar chip, uint addr) |
| 206 | { |
| 207 | if (i2c_wait_for_bb()) { |
| 208 | printf("Timed out waiting for bus\n"); |
| 209 | return 1; |
| 210 | } |
| 211 | |
| 212 | i2c_setaddress(chip); |
| 213 | writel(addr, &i2c_regs_p->ic_cmd_data); |
| 214 | |
| 215 | return 0; |
| 216 | } |
| 217 | |
| 218 | static int i2c_xfer_finish(void) |
| 219 | { |
| 220 | ulong start_stop_det = get_timer(0); |
| 221 | |
| 222 | while (1) { |
| 223 | if ((readl(&i2c_regs_p->ic_raw_intr_stat) & IC_STOP_DET)) { |
| 224 | readl(&i2c_regs_p->ic_clr_stop_det); |
| 225 | break; |
| 226 | } else if (get_timer(start_stop_det) > I2C_STOPDET_TO) { |
| 227 | break; |
| 228 | } |
| 229 | } |
| 230 | |
| 231 | if (i2c_wait_for_bb()) { |
| 232 | printf("Timed out waiting for bus\n"); |
| 233 | return 1; |
| 234 | } |
| 235 | |
| 236 | i2c_flush_rxfifo(); |
| 237 | |
| 238 | /* Wait for read/write operation to complete on actual memory */ |
| 239 | udelay(10000); |
| 240 | |
| 241 | return 0; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * i2c_read - Read from i2c memory |
| 246 | * @chip: target i2c address |
| 247 | * @addr: address to read from |
| 248 | * @alen: |
| 249 | * @buffer: buffer for read data |
| 250 | * @len: no of bytes to be read |
| 251 | * |
| 252 | * Read from i2c memory. |
| 253 | */ |
| 254 | int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) |
| 255 | { |
| 256 | unsigned long start_time_rx; |
| 257 | |
| 258 | if (check_params(addr, alen, buffer, len)) |
| 259 | return 1; |
| 260 | |
| 261 | if (i2c_xfer_init(chip, addr)) |
| 262 | return 1; |
| 263 | |
| 264 | start_time_rx = get_timer(0); |
| 265 | while (len) { |
| 266 | writel(IC_CMD, &i2c_regs_p->ic_cmd_data); |
| 267 | |
| 268 | if (readl(&i2c_regs_p->ic_status) & IC_STATUS_RFNE) { |
| 269 | *buffer++ = (uchar)readl(&i2c_regs_p->ic_cmd_data); |
| 270 | len--; |
| 271 | start_time_rx = get_timer(0); |
| 272 | |
| 273 | } else if (get_timer(start_time_rx) > I2C_BYTE_TO) { |
| 274 | printf("Timed out. i2c read Failed\n"); |
| 275 | return 1; |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | return i2c_xfer_finish(); |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * i2c_write - Write to i2c memory |
| 284 | * @chip: target i2c address |
| 285 | * @addr: address to read from |
| 286 | * @alen: |
| 287 | * @buffer: buffer for read data |
| 288 | * @len: no of bytes to be read |
| 289 | * |
| 290 | * Write to i2c memory. |
| 291 | */ |
| 292 | int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) |
| 293 | { |
| 294 | int nb = len; |
| 295 | unsigned long start_time_tx; |
| 296 | |
| 297 | if (check_params(addr, alen, buffer, len)) |
| 298 | return 1; |
| 299 | |
| 300 | if (i2c_xfer_init(chip, addr)) |
| 301 | return 1; |
| 302 | |
| 303 | start_time_tx = get_timer(0); |
| 304 | while (len) { |
| 305 | if (readl(&i2c_regs_p->ic_status) & IC_STATUS_TFNF) { |
| 306 | writel(*buffer, &i2c_regs_p->ic_cmd_data); |
| 307 | buffer++; |
| 308 | len--; |
| 309 | start_time_tx = get_timer(0); |
| 310 | |
| 311 | } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) { |
| 312 | printf("Timed out. i2c write Failed\n"); |
| 313 | return 1; |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | return i2c_xfer_finish(); |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | * i2c_probe - Probe the i2c chip |
| 322 | */ |
| 323 | int i2c_probe(uchar chip) |
| 324 | { |
| 325 | u32 tmp; |
| 326 | |
| 327 | /* |
| 328 | * Try to read the first location of the chip. |
| 329 | */ |
| 330 | return i2c_read(chip, 0, 1, (uchar *)&tmp, 1); |
| 331 | } |