2 * TI OMAP I2C master mode driver
4 * Copyright (C) 2003 MontaVista Software, Inc.
5 * Copyright (C) 2005 Nokia Corporation
6 * Copyright (C) 2004 - 2007 Texas Instruments.
8 * Originally written by MontaVista Software, Inc.
9 * Additional contributions by:
10 * Tony Lindgren <tony@atomide.com>
11 * Imre Deak <imre.deak@nokia.com>
12 * Juha Yrjölä <juha.yrjola@solidboot.com>
13 * Syed Khasim <x0khasim@ti.com>
14 * Nishant Menon <nm@ti.com>
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31 #include <linux/module.h>
32 #include <linux/delay.h>
33 #include <linux/i2c.h>
34 #include <linux/err.h>
35 #include <linux/interrupt.h>
36 #include <linux/completion.h>
37 #include <linux/platform_device.h>
38 #include <linux/clk.h>
40 #include <linux/slab.h>
41 #include <linux/i2c-omap.h>
42 #include <linux/pm_runtime.h>
44 /* I2C controller revisions */
45 #define OMAP_I2C_OMAP1_REV_2 0x20
47 /* I2C controller revisions present on specific hardware */
48 #define OMAP_I2C_REV_ON_2430 0x36
49 #define OMAP_I2C_REV_ON_3430 0x3C
50 #define OMAP_I2C_REV_ON_3530_4430 0x40
52 /* timeout waiting for the controller to respond */
53 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
55 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
75 /* only on OMAP4430 */
76 OMAP_I2C_IP_V2_REVNB_LO,
77 OMAP_I2C_IP_V2_REVNB_HI,
78 OMAP_I2C_IP_V2_IRQSTATUS_RAW,
79 OMAP_I2C_IP_V2_IRQENABLE_SET,
80 OMAP_I2C_IP_V2_IRQENABLE_CLR,
83 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
84 #define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
85 #define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
86 #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
87 #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
88 #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
89 #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
90 #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
92 /* I2C Status Register (OMAP_I2C_STAT): */
93 #define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
94 #define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
95 #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
96 #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
97 #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
98 #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
99 #define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
100 #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
101 #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
102 #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
103 #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
104 #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
106 /* I2C WE wakeup enable register */
107 #define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
108 #define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
109 #define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
110 #define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
111 #define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
112 #define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
113 #define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
114 #define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
115 #define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
116 #define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
118 #define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
119 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
120 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
121 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
122 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
124 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
125 #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
126 #define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
127 #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
128 #define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
130 /* I2C Configuration Register (OMAP_I2C_CON): */
131 #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
132 #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
133 #define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
134 #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
135 #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
136 #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
137 #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
138 #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
139 #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
140 #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
142 /* I2C SCL time value when Master */
143 #define OMAP_I2C_SCLL_HSSCLL 8
144 #define OMAP_I2C_SCLH_HSSCLH 8
146 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
148 #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
149 #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
150 #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
151 #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
152 #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
153 #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
154 #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
155 #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
158 /* OCP_SYSSTATUS bit definitions */
159 #define SYSS_RESETDONE_MASK (1 << 0)
161 /* OCP_SYSCONFIG bit definitions */
162 #define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
163 #define SYSC_SIDLEMODE_MASK (0x3 << 3)
164 #define SYSC_ENAWAKEUP_MASK (1 << 2)
165 #define SYSC_SOFTRESET_MASK (1 << 1)
166 #define SYSC_AUTOIDLE_MASK (1 << 0)
168 #define SYSC_IDLEMODE_SMART 0x2
169 #define SYSC_CLOCKACTIVITY_FCLK 0x2
171 /* Errata definitions */
172 #define I2C_OMAP_ERRATA_I207 (1 << 0)
173 #define I2C_OMAP3_1P153 (1 << 1)
175 struct omap_i2c_dev {
177 void __iomem *base; /* virtual */
179 int reg_shift; /* bit shift for I2C register addresses */
180 struct completion cmd_complete;
181 struct resource *ioarea;
182 u32 latency; /* maximum mpu wkup latency */
183 void (*set_mpu_wkup_lat)(struct device *dev,
185 u32 speed; /* Speed of bus in Khz */
190 struct i2c_adapter adapter;
191 u8 fifo_size; /* use as flag and value
192 * fifo_size==0 implies no fifo
193 * if set, should be trsh+1
196 unsigned b_hw:1; /* bad h/w fixes */
197 u16 iestate; /* Saved interrupt register */
207 static const u8 reg_map_ip_v1[] = {
208 [OMAP_I2C_REV_REG] = 0x00,
209 [OMAP_I2C_IE_REG] = 0x01,
210 [OMAP_I2C_STAT_REG] = 0x02,
211 [OMAP_I2C_IV_REG] = 0x03,
212 [OMAP_I2C_WE_REG] = 0x03,
213 [OMAP_I2C_SYSS_REG] = 0x04,
214 [OMAP_I2C_BUF_REG] = 0x05,
215 [OMAP_I2C_CNT_REG] = 0x06,
216 [OMAP_I2C_DATA_REG] = 0x07,
217 [OMAP_I2C_SYSC_REG] = 0x08,
218 [OMAP_I2C_CON_REG] = 0x09,
219 [OMAP_I2C_OA_REG] = 0x0a,
220 [OMAP_I2C_SA_REG] = 0x0b,
221 [OMAP_I2C_PSC_REG] = 0x0c,
222 [OMAP_I2C_SCLL_REG] = 0x0d,
223 [OMAP_I2C_SCLH_REG] = 0x0e,
224 [OMAP_I2C_SYSTEST_REG] = 0x0f,
225 [OMAP_I2C_BUFSTAT_REG] = 0x10,
228 static const u8 reg_map_ip_v2[] = {
229 [OMAP_I2C_REV_REG] = 0x04,
230 [OMAP_I2C_IE_REG] = 0x2c,
231 [OMAP_I2C_STAT_REG] = 0x28,
232 [OMAP_I2C_IV_REG] = 0x34,
233 [OMAP_I2C_WE_REG] = 0x34,
234 [OMAP_I2C_SYSS_REG] = 0x90,
235 [OMAP_I2C_BUF_REG] = 0x94,
236 [OMAP_I2C_CNT_REG] = 0x98,
237 [OMAP_I2C_DATA_REG] = 0x9c,
238 [OMAP_I2C_SYSC_REG] = 0x20,
239 [OMAP_I2C_CON_REG] = 0xa4,
240 [OMAP_I2C_OA_REG] = 0xa8,
241 [OMAP_I2C_SA_REG] = 0xac,
242 [OMAP_I2C_PSC_REG] = 0xb0,
243 [OMAP_I2C_SCLL_REG] = 0xb4,
244 [OMAP_I2C_SCLH_REG] = 0xb8,
245 [OMAP_I2C_SYSTEST_REG] = 0xbC,
246 [OMAP_I2C_BUFSTAT_REG] = 0xc0,
247 [OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
248 [OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
249 [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
250 [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
251 [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
254 static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
257 __raw_writew(val, i2c_dev->base +
258 (i2c_dev->regs[reg] << i2c_dev->reg_shift));
261 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
263 return __raw_readw(i2c_dev->base +
264 (i2c_dev->regs[reg] << i2c_dev->reg_shift));
267 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
269 struct omap_i2c_bus_platform_data *pdata;
271 pdata = dev->dev->platform_data;
273 if (pdata->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
274 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
275 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
276 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
277 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
278 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
279 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, dev->syscstate);
280 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
281 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
285 * Don't write to this register if the IE state is 0 as it can
289 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
292 static void omap_i2c_idle(struct omap_i2c_dev *dev)
294 struct omap_i2c_bus_platform_data *pdata;
297 pdata = dev->dev->platform_data;
299 dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
300 if (pdata->rev == OMAP_I2C_IP_VERSION_2)
301 omap_i2c_write_reg(dev, OMAP_I2C_IP_V2_IRQENABLE_CLR, 1);
303 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
305 if (dev->rev < OMAP_I2C_OMAP1_REV_2) {
306 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
308 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
310 /* Flush posted write */
311 omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
315 static int omap_i2c_init(struct omap_i2c_dev *dev)
317 u16 psc = 0, scll = 0, sclh = 0, buf = 0;
318 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
319 unsigned long fclk_rate = 12000000;
320 unsigned long timeout;
321 unsigned long internal_clk = 0;
323 struct omap_i2c_bus_platform_data *pdata;
325 pdata = dev->dev->platform_data;
327 if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
328 /* Disable I2C controller before soft reset */
329 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
330 omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
333 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
334 /* For some reason we need to set the EN bit before the
335 * reset done bit gets set. */
336 timeout = jiffies + OMAP_I2C_TIMEOUT;
337 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
338 while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
339 SYSS_RESETDONE_MASK)) {
340 if (time_after(jiffies, timeout)) {
341 dev_warn(dev->dev, "timeout waiting "
342 "for controller reset\n");
348 /* SYSC register is cleared by the reset; rewrite it */
349 if (dev->rev == OMAP_I2C_REV_ON_2430) {
351 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
354 } else if (dev->rev >= OMAP_I2C_REV_ON_3430) {
355 dev->syscstate = SYSC_AUTOIDLE_MASK;
356 dev->syscstate |= SYSC_ENAWAKEUP_MASK;
357 dev->syscstate |= (SYSC_IDLEMODE_SMART <<
358 __ffs(SYSC_SIDLEMODE_MASK));
359 dev->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
360 __ffs(SYSC_CLOCKACTIVITY_MASK));
362 omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG,
365 * Enabling all wakup sources to stop I2C freezing on
367 * REVISIT: Some wkup sources might not be needed.
369 dev->westate = OMAP_I2C_WE_ALL;
370 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG,
374 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
376 if (pdata->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
378 * The I2C functional clock is the armxor_ck, so there's
379 * no need to get "armxor_ck" separately. Now, if OMAP2420
380 * always returns 12MHz for the functional clock, we can
381 * do this bit unconditionally.
383 fclk = clk_get(dev->dev, "fck");
384 fclk_rate = clk_get_rate(fclk);
387 /* TRM for 5912 says the I2C clock must be prescaled to be
388 * between 7 - 12 MHz. The XOR input clock is typically
389 * 12, 13 or 19.2 MHz. So we should have code that produces:
391 * XOR MHz Divider Prescaler
396 if (fclk_rate > 12000000)
397 psc = fclk_rate / 12000000;
400 if (!(pdata->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
403 * HSI2C controller internal clk rate should be 19.2 Mhz for
404 * HS and for all modes on 2430. On 34xx we can use lower rate
405 * to get longer filter period for better noise suppression.
406 * The filter is iclk (fclk for HS) period.
408 if (dev->speed > 400 ||
409 pdata->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
410 internal_clk = 19200;
411 else if (dev->speed > 100)
415 fclk = clk_get(dev->dev, "fck");
416 fclk_rate = clk_get_rate(fclk) / 1000;
419 /* Compute prescaler divisor */
420 psc = fclk_rate / internal_clk;
423 /* If configured for High Speed */
424 if (dev->speed > 400) {
427 /* For first phase of HS mode */
428 scl = internal_clk / 400;
429 fsscll = scl - (scl / 3) - 7;
430 fssclh = (scl / 3) - 5;
432 /* For second phase of HS mode */
433 scl = fclk_rate / dev->speed;
434 hsscll = scl - (scl / 3) - 7;
435 hssclh = (scl / 3) - 5;
436 } else if (dev->speed > 100) {
440 scl = internal_clk / dev->speed;
441 fsscll = scl - (scl / 3) - 7;
442 fssclh = (scl / 3) - 5;
445 fsscll = internal_clk / (dev->speed * 2) - 7;
446 fssclh = internal_clk / (dev->speed * 2) - 5;
448 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
449 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
451 /* Program desired operating rate */
452 fclk_rate /= (psc + 1) * 1000;
455 scll = fclk_rate / (dev->speed * 2) - 7 + psc;
456 sclh = fclk_rate / (dev->speed * 2) - 7 + psc;
459 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
460 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
462 /* SCL low and high time values */
463 omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
464 omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
466 if (dev->fifo_size) {
467 /* Note: setup required fifo size - 1. RTRSH and XTRSH */
468 buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
469 (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
470 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
473 /* Take the I2C module out of reset: */
474 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
478 if (pdata->flags & OMAP_I2C_FLAG_APPLY_ERRATA_I207)
479 dev->errata |= I2C_OMAP_ERRATA_I207;
481 /* Enable interrupts */
482 dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
483 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
484 OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
485 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
486 omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
487 if (pdata->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
489 dev->scllstate = scll;
490 dev->sclhstate = sclh;
497 * Waiting on Bus Busy
499 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
501 unsigned long timeout;
503 timeout = jiffies + OMAP_I2C_TIMEOUT;
504 while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
505 if (time_after(jiffies, timeout)) {
506 dev_warn(dev->dev, "timeout waiting for bus ready\n");
516 * Low level master read/write transaction.
518 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
519 struct i2c_msg *msg, int stop)
521 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
525 dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
526 msg->addr, msg->len, msg->flags, stop);
531 omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
533 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */
535 dev->buf_len = msg->len;
537 omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
539 /* Clear the FIFO Buffers */
540 w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
541 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
542 omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
544 init_completion(&dev->cmd_complete);
547 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
549 /* High speed configuration */
550 if (dev->speed > 400)
551 w |= OMAP_I2C_CON_OPMODE_HS;
553 if (msg->flags & I2C_M_TEN)
554 w |= OMAP_I2C_CON_XA;
555 if (!(msg->flags & I2C_M_RD))
556 w |= OMAP_I2C_CON_TRX;
558 if (!dev->b_hw && stop)
559 w |= OMAP_I2C_CON_STP;
561 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
564 * Don't write stt and stp together on some hardware.
566 if (dev->b_hw && stop) {
567 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
568 u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
569 while (con & OMAP_I2C_CON_STT) {
570 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
572 /* Let the user know if i2c is in a bad state */
573 if (time_after(jiffies, delay)) {
574 dev_err(dev->dev, "controller timed out "
575 "waiting for start condition to finish\n");
581 w |= OMAP_I2C_CON_STP;
582 w &= ~OMAP_I2C_CON_STT;
583 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
587 * REVISIT: We should abort the transfer on signals, but the bus goes
588 * into arbitration and we're currently unable to recover from it.
590 r = wait_for_completion_timeout(&dev->cmd_complete,
596 dev_err(dev->dev, "controller timed out\n");
601 if (likely(!dev->cmd_err))
604 /* We have an error */
605 if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
606 OMAP_I2C_STAT_XUDF)) {
611 if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
612 if (msg->flags & I2C_M_IGNORE_NAK)
615 w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
616 w |= OMAP_I2C_CON_STP;
617 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
626 * Prepare controller for a transaction and call omap_i2c_xfer_msg
627 * to do the work during IRQ processing.
630 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
632 struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
636 pm_runtime_get_sync(dev->dev);
638 r = omap_i2c_wait_for_bb(dev);
642 if (dev->set_mpu_wkup_lat != NULL)
643 dev->set_mpu_wkup_lat(dev->dev, dev->latency);
645 for (i = 0; i < num; i++) {
646 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
651 if (dev->set_mpu_wkup_lat != NULL)
652 dev->set_mpu_wkup_lat(dev->dev, -1);
657 omap_i2c_wait_for_bb(dev);
659 pm_runtime_put(dev->dev);
664 omap_i2c_func(struct i2c_adapter *adap)
666 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
670 omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
673 complete(&dev->cmd_complete);
677 omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
679 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
682 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *dev, u16 stat)
685 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
686 * Not applicable for OMAP4.
687 * Under certain rare conditions, RDR could be set again
688 * when the bus is busy, then ignore the interrupt and
689 * clear the interrupt.
691 if (stat & OMAP_I2C_STAT_RDR) {
692 /* Step 1: If RDR is set, clear it */
693 omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
696 if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
697 & OMAP_I2C_STAT_BB)) {
700 if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
701 & OMAP_I2C_STAT_RDR) {
702 omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
703 dev_dbg(dev->dev, "RDR when bus is busy.\n");
710 /* rev1 devices are apparently only on some 15xx */
711 #ifdef CONFIG_ARCH_OMAP15XX
714 omap_i2c_omap1_isr(int this_irq, void *dev_id)
716 struct omap_i2c_dev *dev = dev_id;
719 if (pm_runtime_suspended(dev->dev))
722 iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
724 case 0x00: /* None */
726 case 0x01: /* Arbitration lost */
727 dev_err(dev->dev, "Arbitration lost\n");
728 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
730 case 0x02: /* No acknowledgement */
731 omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
732 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
734 case 0x03: /* Register access ready */
735 omap_i2c_complete_cmd(dev, 0);
737 case 0x04: /* Receive data ready */
739 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
743 *dev->buf++ = w >> 8;
747 dev_err(dev->dev, "RRDY IRQ while no data requested\n");
749 case 0x05: /* Transmit data ready */
754 w |= *dev->buf++ << 8;
757 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
759 dev_err(dev->dev, "XRDY IRQ while no data to send\n");
768 #define omap_i2c_omap1_isr NULL
772 * OMAP3430 Errata 1.153: When an XRDY/XDR is hit, wait for XUDF before writing
773 * data to DATA_REG. Otherwise some data bytes can be lost while transferring
774 * them from the memory to the I2C interface.
776 static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err)
778 unsigned long timeout = 10000;
780 while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
781 if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
782 omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
784 *err |= OMAP_I2C_STAT_XUDF;
789 *stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
793 dev_err(dev->dev, "timeout waiting on XUDF bit\n");
801 omap_i2c_isr(int this_irq, void *dev_id)
803 struct omap_i2c_dev *dev = dev_id;
807 struct omap_i2c_bus_platform_data *pdata;
809 pdata = dev->dev->platform_data;
811 if (pm_runtime_suspended(dev->dev))
814 bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
815 while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
816 dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
817 if (count++ == 100) {
818 dev_warn(dev->dev, "Too much work in one IRQ\n");
825 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
826 * acked after the data operation is complete.
827 * Ref: TRM SWPU114Q Figure 18-31
829 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
830 ~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
831 OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
833 if (stat & OMAP_I2C_STAT_NACK) {
834 err |= OMAP_I2C_STAT_NACK;
835 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
838 if (stat & OMAP_I2C_STAT_AL) {
839 dev_err(dev->dev, "Arbitration lost\n");
840 err |= OMAP_I2C_STAT_AL;
843 * ProDB0017052: Clear ARDY bit twice
845 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
847 omap_i2c_ack_stat(dev, stat &
848 (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
849 OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
850 OMAP_I2C_STAT_ARDY));
851 omap_i2c_complete_cmd(dev, err);
854 if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
857 if (dev->errata & I2C_OMAP_ERRATA_I207)
858 i2c_omap_errata_i207(dev, stat);
860 if (dev->fifo_size) {
861 if (stat & OMAP_I2C_STAT_RRDY)
862 num_bytes = dev->fifo_size;
863 else /* read RXSTAT on RDR interrupt */
864 num_bytes = (omap_i2c_read_reg(dev,
865 OMAP_I2C_BUFSTAT_REG)
870 w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
875 * Data reg in 2430, omap3 and
876 * omap4 is 8 bit wide
879 OMAP_I2C_FLAG_16BIT_DATA_REG) {
881 *dev->buf++ = w >> 8;
886 if (stat & OMAP_I2C_STAT_RRDY)
888 "RRDY IRQ while no data"
890 if (stat & OMAP_I2C_STAT_RDR)
892 "RDR IRQ while no data"
897 omap_i2c_ack_stat(dev,
898 stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
901 if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
903 if (dev->fifo_size) {
904 if (stat & OMAP_I2C_STAT_XRDY)
905 num_bytes = dev->fifo_size;
906 else /* read TXSTAT on XDR interrupt */
907 num_bytes = omap_i2c_read_reg(dev,
908 OMAP_I2C_BUFSTAT_REG)
918 * Data reg in 2430, omap3 and
919 * omap4 is 8 bit wide
922 OMAP_I2C_FLAG_16BIT_DATA_REG) {
924 w |= *dev->buf++ << 8;
929 if (stat & OMAP_I2C_STAT_XRDY)
933 if (stat & OMAP_I2C_STAT_XDR)
940 if ((dev->errata & I2C_OMAP3_1P153) &&
941 errata_omap3_1p153(dev, &stat, &err))
944 omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
946 omap_i2c_ack_stat(dev,
947 stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
950 if (stat & OMAP_I2C_STAT_ROVR) {
951 dev_err(dev->dev, "Receive overrun\n");
952 dev->cmd_err |= OMAP_I2C_STAT_ROVR;
954 if (stat & OMAP_I2C_STAT_XUDF) {
955 dev_err(dev->dev, "Transmit underflow\n");
956 dev->cmd_err |= OMAP_I2C_STAT_XUDF;
960 return count ? IRQ_HANDLED : IRQ_NONE;
963 static const struct i2c_algorithm omap_i2c_algo = {
964 .master_xfer = omap_i2c_xfer,
965 .functionality = omap_i2c_func,
969 omap_i2c_probe(struct platform_device *pdev)
971 struct omap_i2c_dev *dev;
972 struct i2c_adapter *adap;
973 struct resource *mem, *irq, *ioarea;
974 struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
979 /* NOTE: driver uses the static register mapping */
980 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
982 dev_err(&pdev->dev, "no mem resource?\n");
985 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
987 dev_err(&pdev->dev, "no irq resource?\n");
991 ioarea = request_mem_region(mem->start, resource_size(mem),
994 dev_err(&pdev->dev, "I2C region already claimed\n");
998 dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
1001 goto err_release_region;
1004 if (pdata != NULL) {
1005 speed = pdata->clkrate;
1006 dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
1008 speed = 100; /* Default speed */
1009 dev->set_mpu_wkup_lat = NULL;
1013 dev->dev = &pdev->dev;
1014 dev->irq = irq->start;
1015 dev->base = ioremap(mem->start, resource_size(mem));
1021 platform_set_drvdata(pdev, dev);
1023 dev->reg_shift = (pdata->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
1025 if (pdata->rev == OMAP_I2C_IP_VERSION_2)
1026 dev->regs = (u8 *)reg_map_ip_v2;
1028 dev->regs = (u8 *)reg_map_ip_v1;
1030 pm_runtime_enable(dev->dev);
1031 pm_runtime_get_sync(dev->dev);
1033 dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
1035 if (dev->rev <= OMAP_I2C_REV_ON_3430)
1036 dev->errata |= I2C_OMAP3_1P153;
1038 if (!(pdata->flags & OMAP_I2C_FLAG_NO_FIFO)) {
1041 /* Set up the fifo size - Get total size */
1042 s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
1043 dev->fifo_size = 0x8 << s;
1046 * Set up notification threshold as half the total available
1047 * size. This is to ensure that we can handle the status on int
1048 * call back latencies.
1051 dev->fifo_size = (dev->fifo_size / 2);
1053 if (dev->rev >= OMAP_I2C_REV_ON_3530_4430)
1054 dev->b_hw = 0; /* Disable hardware fixes */
1056 dev->b_hw = 1; /* Enable hardware fixes */
1058 /* calculate wakeup latency constraint for MPU */
1059 if (dev->set_mpu_wkup_lat != NULL)
1060 dev->latency = (1000000 * dev->fifo_size) /
1064 /* reset ASAP, clearing any IRQs */
1067 isr = (dev->rev < OMAP_I2C_OMAP1_REV_2) ? omap_i2c_omap1_isr :
1069 r = request_irq(dev->irq, isr, 0, pdev->name, dev);
1072 dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
1073 goto err_unuse_clocks;
1076 dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", pdev->id,
1077 pdata->rev, dev->rev >> 4, dev->rev & 0xf, dev->speed);
1079 pm_runtime_put(dev->dev);
1081 adap = &dev->adapter;
1082 i2c_set_adapdata(adap, dev);
1083 adap->owner = THIS_MODULE;
1084 adap->class = I2C_CLASS_HWMON;
1085 strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
1086 adap->algo = &omap_i2c_algo;
1087 adap->dev.parent = &pdev->dev;
1089 /* i2c device drivers may be active on return from add_adapter() */
1090 adap->nr = pdev->id;
1091 r = i2c_add_numbered_adapter(adap);
1093 dev_err(dev->dev, "failure adding adapter\n");
1100 free_irq(dev->irq, dev);
1102 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1103 pm_runtime_put(dev->dev);
1106 platform_set_drvdata(pdev, NULL);
1109 release_mem_region(mem->start, resource_size(mem));
1115 omap_i2c_remove(struct platform_device *pdev)
1117 struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
1118 struct resource *mem;
1120 platform_set_drvdata(pdev, NULL);
1122 free_irq(dev->irq, dev);
1123 i2c_del_adapter(&dev->adapter);
1124 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
1127 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1128 release_mem_region(mem->start, resource_size(mem));
1132 #ifdef CONFIG_PM_RUNTIME
1133 static int omap_i2c_runtime_suspend(struct device *dev)
1135 struct platform_device *pdev = to_platform_device(dev);
1136 struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1138 omap_i2c_idle(_dev);
1143 static int omap_i2c_runtime_resume(struct device *dev)
1145 struct platform_device *pdev = to_platform_device(dev);
1146 struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
1148 omap_i2c_unidle(_dev);
1153 static struct dev_pm_ops omap_i2c_pm_ops = {
1154 .runtime_suspend = omap_i2c_runtime_suspend,
1155 .runtime_resume = omap_i2c_runtime_resume,
1157 #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
1159 #define OMAP_I2C_PM_OPS NULL
1162 static struct platform_driver omap_i2c_driver = {
1163 .probe = omap_i2c_probe,
1164 .remove = omap_i2c_remove,
1167 .owner = THIS_MODULE,
1168 .pm = OMAP_I2C_PM_OPS,
1172 /* I2C may be needed to bring up other drivers */
1174 omap_i2c_init_driver(void)
1176 return platform_driver_register(&omap_i2c_driver);
1178 subsys_initcall(omap_i2c_init_driver);
1180 static void __exit omap_i2c_exit_driver(void)
1182 platform_driver_unregister(&omap_i2c_driver);
1184 module_exit(omap_i2c_exit_driver);
1186 MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
1187 MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
1188 MODULE_LICENSE("GPL");
1189 MODULE_ALIAS("platform:omap_i2c");