Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 1 | /* |
| 2 | * TI OMAP I2C master mode driver |
| 3 | * |
| 4 | * Copyright (C) 2003 MontaVista Software, Inc. |
| 5 | * Copyright (C) 2004 Texas Instruments. |
| 6 | * |
| 7 | * Updated to work with multiple I2C interfaces on 24xx by |
| 8 | * Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com> |
| 9 | * Copyright (C) 2005 Nokia Corporation |
| 10 | * |
Jan Engelhardt | 96de0e2 | 2007-10-19 23:21:04 +0200 | [diff] [blame] | 11 | * Cleaned up by Juha Yrjölä <juha.yrjola@nokia.com> |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 12 | * |
| 13 | * This program is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU General Public License as published by |
| 15 | * the Free Software Foundation; either version 2 of the License, or |
| 16 | * (at your option) any later version. |
| 17 | * |
| 18 | * This program is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | * GNU General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU General Public License |
| 24 | * along with this program; if not, write to the Free Software |
| 25 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 26 | */ |
| 27 | |
| 28 | #include <linux/module.h> |
| 29 | #include <linux/delay.h> |
| 30 | #include <linux/i2c.h> |
| 31 | #include <linux/err.h> |
| 32 | #include <linux/interrupt.h> |
| 33 | #include <linux/completion.h> |
| 34 | #include <linux/platform_device.h> |
| 35 | #include <linux/clk.h> |
| 36 | |
| 37 | #include <asm/io.h> |
| 38 | |
| 39 | /* timeout waiting for the controller to respond */ |
| 40 | #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) |
| 41 | |
| 42 | #define OMAP_I2C_REV_REG 0x00 |
| 43 | #define OMAP_I2C_IE_REG 0x04 |
| 44 | #define OMAP_I2C_STAT_REG 0x08 |
| 45 | #define OMAP_I2C_IV_REG 0x0c |
| 46 | #define OMAP_I2C_SYSS_REG 0x10 |
| 47 | #define OMAP_I2C_BUF_REG 0x14 |
| 48 | #define OMAP_I2C_CNT_REG 0x18 |
| 49 | #define OMAP_I2C_DATA_REG 0x1c |
| 50 | #define OMAP_I2C_SYSC_REG 0x20 |
| 51 | #define OMAP_I2C_CON_REG 0x24 |
| 52 | #define OMAP_I2C_OA_REG 0x28 |
| 53 | #define OMAP_I2C_SA_REG 0x2c |
| 54 | #define OMAP_I2C_PSC_REG 0x30 |
| 55 | #define OMAP_I2C_SCLL_REG 0x34 |
| 56 | #define OMAP_I2C_SCLH_REG 0x38 |
| 57 | #define OMAP_I2C_SYSTEST_REG 0x3c |
| 58 | |
| 59 | /* I2C Interrupt Enable Register (OMAP_I2C_IE): */ |
| 60 | #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */ |
| 61 | #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */ |
| 62 | #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */ |
| 63 | #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */ |
| 64 | #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */ |
| 65 | |
| 66 | /* I2C Status Register (OMAP_I2C_STAT): */ |
| 67 | #define OMAP_I2C_STAT_SBD (1 << 15) /* Single byte data */ |
| 68 | #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */ |
| 69 | #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */ |
| 70 | #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */ |
| 71 | #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */ |
| 72 | #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */ |
| 73 | #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */ |
| 74 | #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */ |
| 75 | #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */ |
| 76 | #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */ |
| 77 | #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */ |
| 78 | |
| 79 | /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */ |
| 80 | #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */ |
| 81 | #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */ |
| 82 | |
| 83 | /* I2C Configuration Register (OMAP_I2C_CON): */ |
| 84 | #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ |
| 85 | #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ |
| 86 | #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ |
| 87 | #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ |
| 88 | #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ |
| 89 | #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */ |
| 90 | #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */ |
| 91 | #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ |
| 92 | #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ |
| 93 | |
| 94 | /* I2C System Test Register (OMAP_I2C_SYSTEST): */ |
| 95 | #ifdef DEBUG |
| 96 | #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ |
| 97 | #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */ |
| 98 | #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */ |
| 99 | #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */ |
| 100 | #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */ |
| 101 | #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */ |
| 102 | #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */ |
| 103 | #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */ |
| 104 | #endif |
| 105 | |
| 106 | /* I2C System Status register (OMAP_I2C_SYSS): */ |
| 107 | #define OMAP_I2C_SYSS_RDONE (1 << 0) /* Reset Done */ |
| 108 | |
| 109 | /* I2C System Configuration Register (OMAP_I2C_SYSC): */ |
| 110 | #define OMAP_I2C_SYSC_SRST (1 << 1) /* Soft Reset */ |
| 111 | |
| 112 | /* REVISIT: Use platform_data instead of module parameters */ |
| 113 | /* Fast Mode = 400 kHz, Standard = 100 kHz */ |
| 114 | static int clock = 100; /* Default: 100 kHz */ |
| 115 | module_param(clock, int, 0); |
| 116 | MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)"); |
| 117 | |
| 118 | struct omap_i2c_dev { |
| 119 | struct device *dev; |
| 120 | void __iomem *base; /* virtual */ |
| 121 | int irq; |
| 122 | struct clk *iclk; /* Interface clock */ |
| 123 | struct clk *fclk; /* Functional clock */ |
| 124 | struct completion cmd_complete; |
| 125 | struct resource *ioarea; |
| 126 | u16 cmd_err; |
| 127 | u8 *buf; |
| 128 | size_t buf_len; |
| 129 | struct i2c_adapter adapter; |
| 130 | unsigned rev1:1; |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 131 | unsigned idle:1; |
| 132 | u16 iestate; /* Saved interrupt register */ |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 133 | }; |
| 134 | |
| 135 | static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev, |
| 136 | int reg, u16 val) |
| 137 | { |
| 138 | __raw_writew(val, i2c_dev->base + reg); |
| 139 | } |
| 140 | |
| 141 | static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg) |
| 142 | { |
| 143 | return __raw_readw(i2c_dev->base + reg); |
| 144 | } |
| 145 | |
| 146 | static int omap_i2c_get_clocks(struct omap_i2c_dev *dev) |
| 147 | { |
| 148 | if (cpu_is_omap16xx() || cpu_is_omap24xx()) { |
| 149 | dev->iclk = clk_get(dev->dev, "i2c_ick"); |
| 150 | if (IS_ERR(dev->iclk)) { |
| 151 | dev->iclk = NULL; |
| 152 | return -ENODEV; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | dev->fclk = clk_get(dev->dev, "i2c_fck"); |
| 157 | if (IS_ERR(dev->fclk)) { |
| 158 | if (dev->iclk != NULL) { |
| 159 | clk_put(dev->iclk); |
| 160 | dev->iclk = NULL; |
| 161 | } |
| 162 | dev->fclk = NULL; |
| 163 | return -ENODEV; |
| 164 | } |
| 165 | |
| 166 | return 0; |
| 167 | } |
| 168 | |
| 169 | static void omap_i2c_put_clocks(struct omap_i2c_dev *dev) |
| 170 | { |
| 171 | clk_put(dev->fclk); |
| 172 | dev->fclk = NULL; |
| 173 | if (dev->iclk != NULL) { |
| 174 | clk_put(dev->iclk); |
| 175 | dev->iclk = NULL; |
| 176 | } |
| 177 | } |
| 178 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 179 | static void omap_i2c_unidle(struct omap_i2c_dev *dev) |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 180 | { |
| 181 | if (dev->iclk != NULL) |
| 182 | clk_enable(dev->iclk); |
| 183 | clk_enable(dev->fclk); |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 184 | if (dev->iestate) |
| 185 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate); |
| 186 | dev->idle = 0; |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 187 | } |
| 188 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 189 | static void omap_i2c_idle(struct omap_i2c_dev *dev) |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 190 | { |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 191 | u16 iv; |
| 192 | |
| 193 | dev->idle = 1; |
| 194 | dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); |
| 195 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0); |
| 196 | if (dev->rev1) |
| 197 | iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */ |
| 198 | else |
| 199 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate); |
| 200 | clk_disable(dev->fclk); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 201 | if (dev->iclk != NULL) |
| 202 | clk_disable(dev->iclk); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 203 | } |
| 204 | |
| 205 | static int omap_i2c_init(struct omap_i2c_dev *dev) |
| 206 | { |
| 207 | u16 psc = 0; |
| 208 | unsigned long fclk_rate = 12000000; |
| 209 | unsigned long timeout; |
| 210 | |
| 211 | if (!dev->rev1) { |
| 212 | omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST); |
| 213 | /* For some reason we need to set the EN bit before the |
| 214 | * reset done bit gets set. */ |
| 215 | timeout = jiffies + OMAP_I2C_TIMEOUT; |
| 216 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); |
| 217 | while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) & |
| 218 | OMAP_I2C_SYSS_RDONE)) { |
| 219 | if (time_after(jiffies, timeout)) { |
Joe Perches | fce3ff0 | 2007-12-12 13:45:24 +0100 | [diff] [blame] | 220 | dev_warn(dev->dev, "timeout waiting " |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 221 | "for controller reset\n"); |
| 222 | return -ETIMEDOUT; |
| 223 | } |
| 224 | msleep(1); |
| 225 | } |
| 226 | } |
| 227 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); |
| 228 | |
| 229 | if (cpu_class_is_omap1()) { |
| 230 | struct clk *armxor_ck; |
| 231 | |
| 232 | armxor_ck = clk_get(NULL, "armxor_ck"); |
| 233 | if (IS_ERR(armxor_ck)) |
| 234 | dev_warn(dev->dev, "Could not get armxor_ck\n"); |
| 235 | else { |
| 236 | fclk_rate = clk_get_rate(armxor_ck); |
| 237 | clk_put(armxor_ck); |
| 238 | } |
| 239 | /* TRM for 5912 says the I2C clock must be prescaled to be |
| 240 | * between 7 - 12 MHz. The XOR input clock is typically |
| 241 | * 12, 13 or 19.2 MHz. So we should have code that produces: |
| 242 | * |
| 243 | * XOR MHz Divider Prescaler |
| 244 | * 12 1 0 |
| 245 | * 13 2 1 |
| 246 | * 19.2 2 1 |
| 247 | */ |
Jean Delvare | d7aef13 | 2006-12-10 21:21:34 +0100 | [diff] [blame] | 248 | if (fclk_rate > 12000000) |
| 249 | psc = fclk_rate / 12000000; |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 250 | } |
| 251 | |
| 252 | /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ |
| 253 | omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc); |
| 254 | |
| 255 | /* Program desired operating rate */ |
| 256 | fclk_rate /= (psc + 1) * 1000; |
| 257 | if (psc > 2) |
| 258 | psc = 2; |
| 259 | |
| 260 | omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, |
| 261 | fclk_rate / (clock * 2) - 7 + psc); |
| 262 | omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, |
| 263 | fclk_rate / (clock * 2) - 7 + psc); |
| 264 | |
| 265 | /* Take the I2C module out of reset: */ |
| 266 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); |
| 267 | |
| 268 | /* Enable interrupts */ |
| 269 | omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, |
| 270 | (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | |
| 271 | OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | |
| 272 | OMAP_I2C_IE_AL)); |
| 273 | return 0; |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Waiting on Bus Busy |
| 278 | */ |
| 279 | static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev) |
| 280 | { |
| 281 | unsigned long timeout; |
| 282 | |
| 283 | timeout = jiffies + OMAP_I2C_TIMEOUT; |
| 284 | while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { |
| 285 | if (time_after(jiffies, timeout)) { |
| 286 | dev_warn(dev->dev, "timeout waiting for bus ready\n"); |
| 287 | return -ETIMEDOUT; |
| 288 | } |
| 289 | msleep(1); |
| 290 | } |
| 291 | |
| 292 | return 0; |
| 293 | } |
| 294 | |
| 295 | /* |
| 296 | * Low level master read/write transaction. |
| 297 | */ |
| 298 | static int omap_i2c_xfer_msg(struct i2c_adapter *adap, |
| 299 | struct i2c_msg *msg, int stop) |
| 300 | { |
| 301 | struct omap_i2c_dev *dev = i2c_get_adapdata(adap); |
| 302 | int r; |
| 303 | u16 w; |
| 304 | |
| 305 | dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", |
| 306 | msg->addr, msg->len, msg->flags, stop); |
| 307 | |
| 308 | if (msg->len == 0) |
| 309 | return -EINVAL; |
| 310 | |
| 311 | omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr); |
| 312 | |
| 313 | /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ |
| 314 | dev->buf = msg->buf; |
| 315 | dev->buf_len = msg->len; |
| 316 | |
| 317 | omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len); |
| 318 | |
| 319 | init_completion(&dev->cmd_complete); |
| 320 | dev->cmd_err = 0; |
| 321 | |
| 322 | w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; |
| 323 | if (msg->flags & I2C_M_TEN) |
| 324 | w |= OMAP_I2C_CON_XA; |
| 325 | if (!(msg->flags & I2C_M_RD)) |
| 326 | w |= OMAP_I2C_CON_TRX; |
| 327 | if (stop) |
| 328 | w |= OMAP_I2C_CON_STP; |
| 329 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); |
| 330 | |
Jarkko Nikula | b7af349 | 2008-11-21 13:39:45 -0800 | [diff] [blame^] | 331 | /* |
| 332 | * REVISIT: We should abort the transfer on signals, but the bus goes |
| 333 | * into arbitration and we're currently unable to recover from it. |
| 334 | */ |
| 335 | r = wait_for_completion_timeout(&dev->cmd_complete, |
| 336 | OMAP_I2C_TIMEOUT); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 337 | dev->buf_len = 0; |
| 338 | if (r < 0) |
| 339 | return r; |
| 340 | if (r == 0) { |
| 341 | dev_err(dev->dev, "controller timed out\n"); |
| 342 | omap_i2c_init(dev); |
| 343 | return -ETIMEDOUT; |
| 344 | } |
| 345 | |
| 346 | if (likely(!dev->cmd_err)) |
| 347 | return 0; |
| 348 | |
| 349 | /* We have an error */ |
| 350 | if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR | |
| 351 | OMAP_I2C_STAT_XUDF)) { |
| 352 | omap_i2c_init(dev); |
| 353 | return -EIO; |
| 354 | } |
| 355 | |
| 356 | if (dev->cmd_err & OMAP_I2C_STAT_NACK) { |
| 357 | if (msg->flags & I2C_M_IGNORE_NAK) |
| 358 | return 0; |
| 359 | if (stop) { |
| 360 | w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG); |
| 361 | w |= OMAP_I2C_CON_STP; |
| 362 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); |
| 363 | } |
| 364 | return -EREMOTEIO; |
| 365 | } |
| 366 | return -EIO; |
| 367 | } |
| 368 | |
| 369 | |
| 370 | /* |
| 371 | * Prepare controller for a transaction and call omap_i2c_xfer_msg |
| 372 | * to do the work during IRQ processing. |
| 373 | */ |
| 374 | static int |
| 375 | omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) |
| 376 | { |
| 377 | struct omap_i2c_dev *dev = i2c_get_adapdata(adap); |
| 378 | int i; |
| 379 | int r; |
| 380 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 381 | omap_i2c_unidle(dev); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 382 | |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 383 | if ((r = omap_i2c_wait_for_bb(dev)) < 0) |
| 384 | goto out; |
| 385 | |
| 386 | for (i = 0; i < num; i++) { |
| 387 | r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); |
| 388 | if (r != 0) |
| 389 | break; |
| 390 | } |
| 391 | |
| 392 | if (r == 0) |
| 393 | r = num; |
| 394 | out: |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 395 | omap_i2c_idle(dev); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 396 | return r; |
| 397 | } |
| 398 | |
| 399 | static u32 |
| 400 | omap_i2c_func(struct i2c_adapter *adap) |
| 401 | { |
| 402 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); |
| 403 | } |
| 404 | |
| 405 | static inline void |
| 406 | omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err) |
| 407 | { |
| 408 | dev->cmd_err |= err; |
| 409 | complete(&dev->cmd_complete); |
| 410 | } |
| 411 | |
| 412 | static inline void |
| 413 | omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat) |
| 414 | { |
| 415 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); |
| 416 | } |
| 417 | |
| 418 | static irqreturn_t |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 419 | omap_i2c_rev1_isr(int this_irq, void *dev_id) |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 420 | { |
| 421 | struct omap_i2c_dev *dev = dev_id; |
| 422 | u16 iv, w; |
| 423 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 424 | if (dev->idle) |
| 425 | return IRQ_NONE; |
| 426 | |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 427 | iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); |
| 428 | switch (iv) { |
| 429 | case 0x00: /* None */ |
| 430 | break; |
| 431 | case 0x01: /* Arbitration lost */ |
| 432 | dev_err(dev->dev, "Arbitration lost\n"); |
| 433 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL); |
| 434 | break; |
| 435 | case 0x02: /* No acknowledgement */ |
| 436 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK); |
| 437 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); |
| 438 | break; |
| 439 | case 0x03: /* Register access ready */ |
| 440 | omap_i2c_complete_cmd(dev, 0); |
| 441 | break; |
| 442 | case 0x04: /* Receive data ready */ |
| 443 | if (dev->buf_len) { |
| 444 | w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); |
| 445 | *dev->buf++ = w; |
| 446 | dev->buf_len--; |
| 447 | if (dev->buf_len) { |
| 448 | *dev->buf++ = w >> 8; |
| 449 | dev->buf_len--; |
| 450 | } |
| 451 | } else |
| 452 | dev_err(dev->dev, "RRDY IRQ while no data requested\n"); |
| 453 | break; |
| 454 | case 0x05: /* Transmit data ready */ |
| 455 | if (dev->buf_len) { |
| 456 | w = *dev->buf++; |
| 457 | dev->buf_len--; |
| 458 | if (dev->buf_len) { |
| 459 | w |= *dev->buf++ << 8; |
| 460 | dev->buf_len--; |
| 461 | } |
| 462 | omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); |
| 463 | } else |
| 464 | dev_err(dev->dev, "XRDY IRQ while no data to send\n"); |
| 465 | break; |
| 466 | default: |
| 467 | return IRQ_NONE; |
| 468 | } |
| 469 | |
| 470 | return IRQ_HANDLED; |
| 471 | } |
| 472 | |
| 473 | static irqreturn_t |
David Howells | 7d12e78 | 2006-10-05 14:55:46 +0100 | [diff] [blame] | 474 | omap_i2c_isr(int this_irq, void *dev_id) |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 475 | { |
| 476 | struct omap_i2c_dev *dev = dev_id; |
| 477 | u16 bits; |
| 478 | u16 stat, w; |
| 479 | int count = 0; |
| 480 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 481 | if (dev->idle) |
| 482 | return IRQ_NONE; |
| 483 | |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 484 | bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG); |
| 485 | while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) { |
| 486 | dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat); |
| 487 | if (count++ == 100) { |
| 488 | dev_warn(dev->dev, "Too much work in one IRQ\n"); |
| 489 | break; |
| 490 | } |
| 491 | |
| 492 | omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat); |
| 493 | |
| 494 | if (stat & OMAP_I2C_STAT_ARDY) { |
| 495 | omap_i2c_complete_cmd(dev, 0); |
| 496 | continue; |
| 497 | } |
| 498 | if (stat & OMAP_I2C_STAT_RRDY) { |
| 499 | w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG); |
| 500 | if (dev->buf_len) { |
| 501 | *dev->buf++ = w; |
| 502 | dev->buf_len--; |
| 503 | if (dev->buf_len) { |
| 504 | *dev->buf++ = w >> 8; |
| 505 | dev->buf_len--; |
| 506 | } |
| 507 | } else |
Joe Perches | fce3ff0 | 2007-12-12 13:45:24 +0100 | [diff] [blame] | 508 | dev_err(dev->dev, "RRDY IRQ while no data " |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 509 | "requested\n"); |
| 510 | omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY); |
| 511 | continue; |
| 512 | } |
| 513 | if (stat & OMAP_I2C_STAT_XRDY) { |
| 514 | w = 0; |
| 515 | if (dev->buf_len) { |
| 516 | w = *dev->buf++; |
| 517 | dev->buf_len--; |
| 518 | if (dev->buf_len) { |
| 519 | w |= *dev->buf++ << 8; |
| 520 | dev->buf_len--; |
| 521 | } |
| 522 | } else |
Joe Perches | fce3ff0 | 2007-12-12 13:45:24 +0100 | [diff] [blame] | 523 | dev_err(dev->dev, "XRDY IRQ while no " |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 524 | "data to send\n"); |
| 525 | omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w); |
| 526 | omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY); |
| 527 | continue; |
| 528 | } |
| 529 | if (stat & OMAP_I2C_STAT_ROVR) { |
| 530 | dev_err(dev->dev, "Receive overrun\n"); |
| 531 | dev->cmd_err |= OMAP_I2C_STAT_ROVR; |
| 532 | } |
| 533 | if (stat & OMAP_I2C_STAT_XUDF) { |
| 534 | dev_err(dev->dev, "Transmit overflow\n"); |
| 535 | dev->cmd_err |= OMAP_I2C_STAT_XUDF; |
| 536 | } |
| 537 | if (stat & OMAP_I2C_STAT_NACK) { |
| 538 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK); |
| 539 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, |
| 540 | OMAP_I2C_CON_STP); |
| 541 | } |
| 542 | if (stat & OMAP_I2C_STAT_AL) { |
| 543 | dev_err(dev->dev, "Arbitration lost\n"); |
| 544 | omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL); |
| 545 | } |
| 546 | } |
| 547 | |
| 548 | return count ? IRQ_HANDLED : IRQ_NONE; |
| 549 | } |
| 550 | |
Jean Delvare | 8f9082c | 2006-09-03 22:39:46 +0200 | [diff] [blame] | 551 | static const struct i2c_algorithm omap_i2c_algo = { |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 552 | .master_xfer = omap_i2c_xfer, |
| 553 | .functionality = omap_i2c_func, |
| 554 | }; |
| 555 | |
| 556 | static int |
| 557 | omap_i2c_probe(struct platform_device *pdev) |
| 558 | { |
| 559 | struct omap_i2c_dev *dev; |
| 560 | struct i2c_adapter *adap; |
| 561 | struct resource *mem, *irq, *ioarea; |
| 562 | int r; |
| 563 | |
| 564 | /* NOTE: driver uses the static register mapping */ |
| 565 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 566 | if (!mem) { |
| 567 | dev_err(&pdev->dev, "no mem resource?\n"); |
| 568 | return -ENODEV; |
| 569 | } |
| 570 | irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| 571 | if (!irq) { |
| 572 | dev_err(&pdev->dev, "no irq resource?\n"); |
| 573 | return -ENODEV; |
| 574 | } |
| 575 | |
| 576 | ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1, |
| 577 | pdev->name); |
| 578 | if (!ioarea) { |
| 579 | dev_err(&pdev->dev, "I2C region already claimed\n"); |
| 580 | return -EBUSY; |
| 581 | } |
| 582 | |
| 583 | if (clock > 200) |
| 584 | clock = 400; /* Fast mode */ |
| 585 | else |
| 586 | clock = 100; /* Standard mode */ |
| 587 | |
| 588 | dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL); |
| 589 | if (!dev) { |
| 590 | r = -ENOMEM; |
| 591 | goto err_release_region; |
| 592 | } |
| 593 | |
| 594 | dev->dev = &pdev->dev; |
| 595 | dev->irq = irq->start; |
Russell King | 55c381e | 2008-09-04 14:07:22 +0100 | [diff] [blame] | 596 | dev->base = ioremap(mem->start, mem->end - mem->start + 1); |
| 597 | if (!dev->base) { |
| 598 | r = -ENOMEM; |
| 599 | goto err_free_mem; |
| 600 | } |
| 601 | |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 602 | platform_set_drvdata(pdev, dev); |
| 603 | |
| 604 | if ((r = omap_i2c_get_clocks(dev)) != 0) |
Russell King | 55c381e | 2008-09-04 14:07:22 +0100 | [diff] [blame] | 605 | goto err_iounmap; |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 606 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 607 | omap_i2c_unidle(dev); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 608 | |
| 609 | if (cpu_is_omap15xx()) |
| 610 | dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20; |
| 611 | |
| 612 | /* reset ASAP, clearing any IRQs */ |
| 613 | omap_i2c_init(dev); |
| 614 | |
| 615 | r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr, |
| 616 | 0, pdev->name, dev); |
| 617 | |
| 618 | if (r) { |
| 619 | dev_err(dev->dev, "failure requesting irq %i\n", dev->irq); |
| 620 | goto err_unuse_clocks; |
| 621 | } |
| 622 | r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff; |
| 623 | dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n", |
| 624 | pdev->id, r >> 4, r & 0xf, clock); |
| 625 | |
| 626 | adap = &dev->adapter; |
| 627 | i2c_set_adapdata(adap, dev); |
| 628 | adap->owner = THIS_MODULE; |
| 629 | adap->class = I2C_CLASS_HWMON; |
| 630 | strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); |
| 631 | adap->algo = &omap_i2c_algo; |
| 632 | adap->dev.parent = &pdev->dev; |
| 633 | |
| 634 | /* i2c device drivers may be active on return from add_adapter() */ |
David Brownell | 7c17549 | 2007-05-01 23:26:32 +0200 | [diff] [blame] | 635 | adap->nr = pdev->id; |
| 636 | r = i2c_add_numbered_adapter(adap); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 637 | if (r) { |
| 638 | dev_err(dev->dev, "failure adding adapter\n"); |
| 639 | goto err_free_irq; |
| 640 | } |
| 641 | |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 642 | omap_i2c_idle(dev); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 643 | |
| 644 | return 0; |
| 645 | |
| 646 | err_free_irq: |
| 647 | free_irq(dev->irq, dev); |
| 648 | err_unuse_clocks: |
Tony Lindgren | 3e39752 | 2008-01-14 21:53:30 +0100 | [diff] [blame] | 649 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); |
Tony Lindgren | f08ac4e | 2008-03-23 20:28:20 +0100 | [diff] [blame] | 650 | omap_i2c_idle(dev); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 651 | omap_i2c_put_clocks(dev); |
Russell King | 55c381e | 2008-09-04 14:07:22 +0100 | [diff] [blame] | 652 | err_iounmap: |
| 653 | iounmap(dev->base); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 654 | err_free_mem: |
| 655 | platform_set_drvdata(pdev, NULL); |
| 656 | kfree(dev); |
| 657 | err_release_region: |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 658 | release_mem_region(mem->start, (mem->end - mem->start) + 1); |
| 659 | |
| 660 | return r; |
| 661 | } |
| 662 | |
| 663 | static int |
| 664 | omap_i2c_remove(struct platform_device *pdev) |
| 665 | { |
| 666 | struct omap_i2c_dev *dev = platform_get_drvdata(pdev); |
| 667 | struct resource *mem; |
| 668 | |
| 669 | platform_set_drvdata(pdev, NULL); |
| 670 | |
| 671 | free_irq(dev->irq, dev); |
| 672 | i2c_del_adapter(&dev->adapter); |
| 673 | omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0); |
| 674 | omap_i2c_put_clocks(dev); |
Russell King | 55c381e | 2008-09-04 14:07:22 +0100 | [diff] [blame] | 675 | iounmap(dev->base); |
Komal Shah | 010d442c4 | 2006-08-13 23:44:09 +0200 | [diff] [blame] | 676 | kfree(dev); |
| 677 | mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 678 | release_mem_region(mem->start, (mem->end - mem->start) + 1); |
| 679 | return 0; |
| 680 | } |
| 681 | |
| 682 | static struct platform_driver omap_i2c_driver = { |
| 683 | .probe = omap_i2c_probe, |
| 684 | .remove = omap_i2c_remove, |
| 685 | .driver = { |
| 686 | .name = "i2c_omap", |
| 687 | .owner = THIS_MODULE, |
| 688 | }, |
| 689 | }; |
| 690 | |
| 691 | /* I2C may be needed to bring up other drivers */ |
| 692 | static int __init |
| 693 | omap_i2c_init_driver(void) |
| 694 | { |
| 695 | return platform_driver_register(&omap_i2c_driver); |
| 696 | } |
| 697 | subsys_initcall(omap_i2c_init_driver); |
| 698 | |
| 699 | static void __exit omap_i2c_exit_driver(void) |
| 700 | { |
| 701 | platform_driver_unregister(&omap_i2c_driver); |
| 702 | } |
| 703 | module_exit(omap_i2c_exit_driver); |
| 704 | |
| 705 | MODULE_AUTHOR("MontaVista Software, Inc. (and others)"); |
| 706 | MODULE_DESCRIPTION("TI OMAP I2C bus adapter"); |
| 707 | MODULE_LICENSE("GPL"); |
Kay Sievers | add8eda | 2008-04-22 22:16:49 +0200 | [diff] [blame] | 708 | MODULE_ALIAS("platform:i2c_omap"); |