2 * Synopsys DesignWare I2C adapter driver (master only).
4 * Based on the TI DAVINCI I2C adapter driver.
6 * Copyright (C) 2006 Texas Instruments.
7 * Copyright (C) 2007 MontaVista Software Inc.
8 * Copyright (C) 2009 Provigent Ltd.
10 * ----------------------------------------------------------------------------
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 * ----------------------------------------------------------------------------
28 #include <linux/export.h>
29 #include <linux/clk.h>
30 #include <linux/errno.h>
31 #include <linux/err.h>
32 #include <linux/i2c.h>
33 #include <linux/interrupt.h>
35 #include <linux/pm_runtime.h>
36 #include <linux/delay.h>
37 #include <linux/module.h>
38 #include "i2c-designware-core.h"
45 #define DW_IC_DATA_CMD 0x10
46 #define DW_IC_SS_SCL_HCNT 0x14
47 #define DW_IC_SS_SCL_LCNT 0x18
48 #define DW_IC_FS_SCL_HCNT 0x1c
49 #define DW_IC_FS_SCL_LCNT 0x20
50 #define DW_IC_INTR_STAT 0x2c
51 #define DW_IC_INTR_MASK 0x30
52 #define DW_IC_RAW_INTR_STAT 0x34
53 #define DW_IC_RX_TL 0x38
54 #define DW_IC_TX_TL 0x3c
55 #define DW_IC_CLR_INTR 0x40
56 #define DW_IC_CLR_RX_UNDER 0x44
57 #define DW_IC_CLR_RX_OVER 0x48
58 #define DW_IC_CLR_TX_OVER 0x4c
59 #define DW_IC_CLR_RD_REQ 0x50
60 #define DW_IC_CLR_TX_ABRT 0x54
61 #define DW_IC_CLR_RX_DONE 0x58
62 #define DW_IC_CLR_ACTIVITY 0x5c
63 #define DW_IC_CLR_STOP_DET 0x60
64 #define DW_IC_CLR_START_DET 0x64
65 #define DW_IC_CLR_GEN_CALL 0x68
66 #define DW_IC_ENABLE 0x6c
67 #define DW_IC_STATUS 0x70
68 #define DW_IC_TXFLR 0x74
69 #define DW_IC_RXFLR 0x78
70 #define DW_IC_SDA_HOLD 0x7c
71 #define DW_IC_TX_ABRT_SOURCE 0x80
72 #define DW_IC_ENABLE_STATUS 0x9c
73 #define DW_IC_COMP_PARAM_1 0xf4
74 #define DW_IC_COMP_VERSION 0xf8
75 #define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A
76 #define DW_IC_COMP_TYPE 0xfc
77 #define DW_IC_COMP_TYPE_VALUE 0x44570140
79 #define DW_IC_INTR_RX_UNDER 0x001
80 #define DW_IC_INTR_RX_OVER 0x002
81 #define DW_IC_INTR_RX_FULL 0x004
82 #define DW_IC_INTR_TX_OVER 0x008
83 #define DW_IC_INTR_TX_EMPTY 0x010
84 #define DW_IC_INTR_RD_REQ 0x020
85 #define DW_IC_INTR_TX_ABRT 0x040
86 #define DW_IC_INTR_RX_DONE 0x080
87 #define DW_IC_INTR_ACTIVITY 0x100
88 #define DW_IC_INTR_STOP_DET 0x200
89 #define DW_IC_INTR_START_DET 0x400
90 #define DW_IC_INTR_GEN_CALL 0x800
92 #define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \
93 DW_IC_INTR_TX_EMPTY | \
94 DW_IC_INTR_TX_ABRT | \
97 #define DW_IC_STATUS_ACTIVITY 0x1
99 #define DW_IC_ERR_TX_ABRT 0x1
101 #define DW_IC_TAR_10BITADDR_MASTER BIT(12)
106 #define STATUS_IDLE 0x0
107 #define STATUS_WRITE_IN_PROGRESS 0x1
108 #define STATUS_READ_IN_PROGRESS 0x2
110 #define TIMEOUT 20 /* ms */
113 * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
115 * only expected abort codes are listed here
116 * refer to the datasheet for the full list
118 #define ABRT_7B_ADDR_NOACK 0
119 #define ABRT_10ADDR1_NOACK 1
120 #define ABRT_10ADDR2_NOACK 2
121 #define ABRT_TXDATA_NOACK 3
122 #define ABRT_GCALL_NOACK 4
123 #define ABRT_GCALL_READ 5
124 #define ABRT_SBYTE_ACKDET 7
125 #define ABRT_SBYTE_NORSTRT 9
126 #define ABRT_10B_RD_NORSTRT 10
127 #define ABRT_MASTER_DIS 11
130 #define DW_IC_TX_ABRT_7B_ADDR_NOACK (1UL << ABRT_7B_ADDR_NOACK)
131 #define DW_IC_TX_ABRT_10ADDR1_NOACK (1UL << ABRT_10ADDR1_NOACK)
132 #define DW_IC_TX_ABRT_10ADDR2_NOACK (1UL << ABRT_10ADDR2_NOACK)
133 #define DW_IC_TX_ABRT_TXDATA_NOACK (1UL << ABRT_TXDATA_NOACK)
134 #define DW_IC_TX_ABRT_GCALL_NOACK (1UL << ABRT_GCALL_NOACK)
135 #define DW_IC_TX_ABRT_GCALL_READ (1UL << ABRT_GCALL_READ)
136 #define DW_IC_TX_ABRT_SBYTE_ACKDET (1UL << ABRT_SBYTE_ACKDET)
137 #define DW_IC_TX_ABRT_SBYTE_NORSTRT (1UL << ABRT_SBYTE_NORSTRT)
138 #define DW_IC_TX_ABRT_10B_RD_NORSTRT (1UL << ABRT_10B_RD_NORSTRT)
139 #define DW_IC_TX_ABRT_MASTER_DIS (1UL << ABRT_MASTER_DIS)
140 #define DW_IC_TX_ARB_LOST (1UL << ARB_LOST)
142 #define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
143 DW_IC_TX_ABRT_10ADDR1_NOACK | \
144 DW_IC_TX_ABRT_10ADDR2_NOACK | \
145 DW_IC_TX_ABRT_TXDATA_NOACK | \
146 DW_IC_TX_ABRT_GCALL_NOACK)
148 static char *abort_sources[] = {
149 [ABRT_7B_ADDR_NOACK] =
150 "slave address not acknowledged (7bit mode)",
151 [ABRT_10ADDR1_NOACK] =
152 "first address byte not acknowledged (10bit mode)",
153 [ABRT_10ADDR2_NOACK] =
154 "second address byte not acknowledged (10bit mode)",
155 [ABRT_TXDATA_NOACK] =
156 "data not acknowledged",
158 "no acknowledgement for a general call",
160 "read after general call",
161 [ABRT_SBYTE_ACKDET] =
162 "start byte acknowledged",
163 [ABRT_SBYTE_NORSTRT] =
164 "trying to send start byte when restart is disabled",
165 [ABRT_10B_RD_NORSTRT] =
166 "trying to read when restart is disabled (10bit mode)",
168 "trying to use disabled adapter",
173 u32 dw_readl(struct dw_i2c_dev *dev, int offset)
177 if (dev->accessor_flags & ACCESS_16BIT)
178 value = readw(dev->base + offset) |
179 (readw(dev->base + offset + 2) << 16);
181 value = readl(dev->base + offset);
183 if (dev->accessor_flags & ACCESS_SWAP)
184 return swab32(value);
189 void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
191 if (dev->accessor_flags & ACCESS_SWAP)
194 if (dev->accessor_flags & ACCESS_16BIT) {
195 writew((u16)b, dev->base + offset);
196 writew((u16)(b >> 16), dev->base + offset + 2);
198 writel(b, dev->base + offset);
203 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
206 * DesignWare I2C core doesn't seem to have solid strategy to meet
207 * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
208 * will result in violation of the tHD;STA spec.
212 * Conditional expression:
214 * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
216 * This is based on the DW manuals, and represents an ideal
217 * configuration. The resulting I2C bus speed will be
218 * faster than any of the others.
220 * If your hardware is free from tHD;STA issue, try this one.
222 return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
225 * Conditional expression:
227 * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
229 * This is just experimental rule; the tHD;STA period turned
230 * out to be proportinal to (_HCNT + 3). With this setting,
231 * we could meet both tHIGH and tHD;STA timing specs.
233 * If unsure, you'd better to take this alternative.
235 * The reason why we need to take into account "tf" here,
236 * is the same as described in i2c_dw_scl_lcnt().
238 return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
241 static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
244 * Conditional expression:
246 * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
248 * DW I2C core starts counting the SCL CNTs for the LOW period
249 * of the SCL clock (tLOW) as soon as it pulls the SCL line.
250 * In order to meet the tLOW timing spec, we need to take into
251 * account the fall time of SCL signal (tf). Default tf value
252 * should be 0.3 us, for safety.
254 return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
257 static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
262 dw_writel(dev, enable, DW_IC_ENABLE);
263 if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
267 * Wait 10 times the signaling period of the highest I2C
268 * transfer supported by the driver (for 400KHz this is
269 * 25us) as described in the DesignWare I2C databook.
271 usleep_range(25, 250);
274 dev_warn(dev->dev, "timeout in %sabling adapter\n",
275 enable ? "en" : "dis");
279 * i2c_dw_init() - initialize the designware i2c master hardware
280 * @dev: device private data
282 * This functions configures and enables the I2C master.
283 * This function is called during I2C init function, and in case of timeout at
286 int i2c_dw_init(struct dw_i2c_dev *dev)
292 input_clock_khz = dev->get_clk_rate_khz(dev);
294 reg = dw_readl(dev, DW_IC_COMP_TYPE);
295 if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
296 /* Configure register endianess access */
297 dev->accessor_flags |= ACCESS_SWAP;
298 } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
299 /* Configure register access mode 16bit */
300 dev->accessor_flags |= ACCESS_16BIT;
301 } else if (reg != DW_IC_COMP_TYPE_VALUE) {
302 dev_err(dev->dev, "Unknown Synopsys component type: "
307 /* Disable the adapter */
308 __i2c_dw_enable(dev, false);
310 /* set standard and fast speed deviders for high/low periods */
313 hcnt = i2c_dw_scl_hcnt(input_clock_khz,
314 40, /* tHD;STA = tHIGH = 4.0 us */
316 0, /* 0: DW default, 1: Ideal */
318 lcnt = i2c_dw_scl_lcnt(input_clock_khz,
319 47, /* tLOW = 4.7 us */
323 /* Allow platforms to specify the ideal HCNT and LCNT values */
324 if (dev->ss_hcnt && dev->ss_lcnt) {
328 dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
329 dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
330 dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
333 hcnt = i2c_dw_scl_hcnt(input_clock_khz,
334 6, /* tHD;STA = tHIGH = 0.6 us */
336 0, /* 0: DW default, 1: Ideal */
338 lcnt = i2c_dw_scl_lcnt(input_clock_khz,
339 13, /* tLOW = 1.3 us */
343 if (dev->fs_hcnt && dev->fs_lcnt) {
347 dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
348 dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
349 dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
351 /* Configure SDA Hold Time if required */
352 if (dev->sda_hold_time) {
353 reg = dw_readl(dev, DW_IC_COMP_VERSION);
354 if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
355 dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
358 "Hardware too old to adjust SDA hold time.");
361 /* Configure Tx/Rx FIFO threshold levels */
362 dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);
363 dw_writel(dev, 0, DW_IC_RX_TL);
365 /* configure the i2c master */
366 dw_writel(dev, dev->master_cfg , DW_IC_CON);
369 EXPORT_SYMBOL_GPL(i2c_dw_init);
372 * Waiting for bus not busy
374 static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
376 int timeout = TIMEOUT;
378 while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
380 dev_warn(dev->dev, "timeout waiting for bus ready\n");
384 usleep_range(1000, 1100);
390 static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
392 struct i2c_msg *msgs = dev->msgs;
393 u32 ic_con, ic_tar = 0;
395 /* Disable the adapter */
396 __i2c_dw_enable(dev, false);
398 /* if the slave address is ten bit address, enable 10BITADDR */
399 ic_con = dw_readl(dev, DW_IC_CON);
400 if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
401 ic_con |= DW_IC_CON_10BITADDR_MASTER;
403 * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
404 * mode has to be enabled via bit 12 of IC_TAR register.
405 * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be
406 * detected from registers.
408 ic_tar = DW_IC_TAR_10BITADDR_MASTER;
410 ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
413 dw_writel(dev, ic_con, DW_IC_CON);
416 * Set the slave (target) address and enable 10-bit addressing mode
419 dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
421 /* Enable the adapter */
422 __i2c_dw_enable(dev, true);
424 /* Clear and enable interrupts */
425 i2c_dw_clear_int(dev);
426 dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK);
430 * Initiate (and continue) low level master read/write transaction.
431 * This function is only called from i2c_dw_isr, and pumping i2c_msg
432 * messages into the tx buffer. Even if the size of i2c_msg data is
433 * longer than the size of the tx buffer, it handles everything.
436 i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
438 struct i2c_msg *msgs = dev->msgs;
440 int tx_limit, rx_limit;
441 u32 addr = msgs[dev->msg_write_idx].addr;
442 u32 buf_len = dev->tx_buf_len;
443 u8 *buf = dev->tx_buf;
444 bool need_restart = false;
446 intr_mask = DW_IC_INTR_DEFAULT_MASK;
448 for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
450 * if target address has changed, we need to
451 * reprogram the target address in the i2c
452 * adapter when we are done with this transfer
454 if (msgs[dev->msg_write_idx].addr != addr) {
456 "%s: invalid target address\n", __func__);
457 dev->msg_err = -EINVAL;
461 if (msgs[dev->msg_write_idx].len == 0) {
463 "%s: invalid message length\n", __func__);
464 dev->msg_err = -EINVAL;
468 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
470 buf = msgs[dev->msg_write_idx].buf;
471 buf_len = msgs[dev->msg_write_idx].len;
473 /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
474 * IC_RESTART_EN are set, we must manually
475 * set restart bit between messages.
477 if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
478 (dev->msg_write_idx > 0))
482 tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
483 rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
485 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
489 * If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
490 * manually set the stop bit. However, it cannot be
491 * detected from the registers so we set it always
492 * when writing/reading the last byte.
494 if (dev->msg_write_idx == dev->msgs_num - 1 &&
500 need_restart = false;
503 if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
505 /* avoid rx buffer overrun */
506 if (rx_limit - dev->rx_outstanding <= 0)
509 dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
511 dev->rx_outstanding++;
513 dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
514 tx_limit--; buf_len--;
518 dev->tx_buf_len = buf_len;
521 /* more bytes to be written */
522 dev->status |= STATUS_WRITE_IN_PROGRESS;
525 dev->status &= ~STATUS_WRITE_IN_PROGRESS;
529 * If i2c_msg index search is completed, we don't need TX_EMPTY
530 * interrupt any more.
532 if (dev->msg_write_idx == dev->msgs_num)
533 intr_mask &= ~DW_IC_INTR_TX_EMPTY;
538 dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
542 i2c_dw_read(struct dw_i2c_dev *dev)
544 struct i2c_msg *msgs = dev->msgs;
547 for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
551 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
554 if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
555 len = msgs[dev->msg_read_idx].len;
556 buf = msgs[dev->msg_read_idx].buf;
558 len = dev->rx_buf_len;
562 rx_valid = dw_readl(dev, DW_IC_RXFLR);
564 for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
565 *buf++ = dw_readl(dev, DW_IC_DATA_CMD);
566 dev->rx_outstanding--;
570 dev->status |= STATUS_READ_IN_PROGRESS;
571 dev->rx_buf_len = len;
575 dev->status &= ~STATUS_READ_IN_PROGRESS;
579 static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
581 unsigned long abort_source = dev->abort_source;
584 if (abort_source & DW_IC_TX_ABRT_NOACK) {
585 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
587 "%s: %s\n", __func__, abort_sources[i]);
591 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
592 dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
594 if (abort_source & DW_IC_TX_ARB_LOST)
596 else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
597 return -EINVAL; /* wrong msgs[] data */
603 * Prepare controller for a transaction and call i2c_dw_xfer_msg
606 i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
608 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
611 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
613 mutex_lock(&dev->lock);
614 pm_runtime_get_sync(dev->dev);
616 INIT_COMPLETION(dev->cmd_complete);
620 dev->msg_write_idx = 0;
621 dev->msg_read_idx = 0;
623 dev->status = STATUS_IDLE;
624 dev->abort_source = 0;
625 dev->rx_outstanding = 0;
627 ret = i2c_dw_wait_bus_not_busy(dev);
631 /* start the transfers */
632 i2c_dw_xfer_init(dev);
634 /* wait for tx to complete */
635 ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);
637 dev_err(dev->dev, "controller timed out\n");
638 /* i2c_dw_init implicitly disables the adapter */
645 * We must disable the adapter before unlocking the &dev->lock mutex
646 * below. Otherwise the hardware might continue generating interrupts
647 * which in turn causes a race condition with the following transfer.
648 * Needs some more investigation if the additional interrupts are
649 * a hardware bug or this driver doesn't handle them correctly yet.
651 __i2c_dw_enable(dev, false);
659 if (likely(!dev->cmd_err)) {
664 /* We have an error */
665 if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
666 ret = i2c_dw_handle_tx_abort(dev);
672 pm_runtime_mark_last_busy(dev->dev);
673 pm_runtime_put_autosuspend(dev->dev);
674 mutex_unlock(&dev->lock);
678 EXPORT_SYMBOL_GPL(i2c_dw_xfer);
680 u32 i2c_dw_func(struct i2c_adapter *adap)
682 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
683 return dev->functionality;
685 EXPORT_SYMBOL_GPL(i2c_dw_func);
687 static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
692 * The IC_INTR_STAT register just indicates "enabled" interrupts.
693 * Ths unmasked raw version of interrupt status bits are available
694 * in the IC_RAW_INTR_STAT register.
697 * stat = dw_readl(IC_INTR_STAT);
699 * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
701 * The raw version might be useful for debugging purposes.
703 stat = dw_readl(dev, DW_IC_INTR_STAT);
706 * Do not use the IC_CLR_INTR register to clear interrupts, or
707 * you'll miss some interrupts, triggered during the period from
708 * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
710 * Instead, use the separately-prepared IC_CLR_* registers.
712 if (stat & DW_IC_INTR_RX_UNDER)
713 dw_readl(dev, DW_IC_CLR_RX_UNDER);
714 if (stat & DW_IC_INTR_RX_OVER)
715 dw_readl(dev, DW_IC_CLR_RX_OVER);
716 if (stat & DW_IC_INTR_TX_OVER)
717 dw_readl(dev, DW_IC_CLR_TX_OVER);
718 if (stat & DW_IC_INTR_RD_REQ)
719 dw_readl(dev, DW_IC_CLR_RD_REQ);
720 if (stat & DW_IC_INTR_TX_ABRT) {
722 * The IC_TX_ABRT_SOURCE register is cleared whenever
723 * the IC_CLR_TX_ABRT is read. Preserve it beforehand.
725 dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
726 dw_readl(dev, DW_IC_CLR_TX_ABRT);
728 if (stat & DW_IC_INTR_RX_DONE)
729 dw_readl(dev, DW_IC_CLR_RX_DONE);
730 if (stat & DW_IC_INTR_ACTIVITY)
731 dw_readl(dev, DW_IC_CLR_ACTIVITY);
732 if (stat & DW_IC_INTR_STOP_DET)
733 dw_readl(dev, DW_IC_CLR_STOP_DET);
734 if (stat & DW_IC_INTR_START_DET)
735 dw_readl(dev, DW_IC_CLR_START_DET);
736 if (stat & DW_IC_INTR_GEN_CALL)
737 dw_readl(dev, DW_IC_CLR_GEN_CALL);
743 * Interrupt service routine. This gets called whenever an I2C interrupt
746 irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
748 struct dw_i2c_dev *dev = dev_id;
751 enabled = dw_readl(dev, DW_IC_ENABLE);
752 stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
753 dev_dbg(dev->dev, "%s: %s enabled= 0x%x stat=0x%x\n", __func__,
754 dev->adapter.name, enabled, stat);
755 if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
758 stat = i2c_dw_read_clear_intrbits(dev);
760 if (stat & DW_IC_INTR_TX_ABRT) {
761 dev->cmd_err |= DW_IC_ERR_TX_ABRT;
762 dev->status = STATUS_IDLE;
765 * Anytime TX_ABRT is set, the contents of the tx/rx
766 * buffers are flushed. Make sure to skip them.
768 dw_writel(dev, 0, DW_IC_INTR_MASK);
772 if (stat & DW_IC_INTR_RX_FULL)
775 if (stat & DW_IC_INTR_TX_EMPTY)
776 i2c_dw_xfer_msg(dev);
779 * No need to modify or disable the interrupt mask here.
780 * i2c_dw_xfer_msg() will take care of it according to
781 * the current transmit status.
785 if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
786 complete(&dev->cmd_complete);
790 EXPORT_SYMBOL_GPL(i2c_dw_isr);
792 void i2c_dw_enable(struct dw_i2c_dev *dev)
794 /* Enable the adapter */
795 __i2c_dw_enable(dev, true);
797 EXPORT_SYMBOL_GPL(i2c_dw_enable);
799 u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev)
801 return dw_readl(dev, DW_IC_ENABLE);
803 EXPORT_SYMBOL_GPL(i2c_dw_is_enabled);
805 void i2c_dw_disable(struct dw_i2c_dev *dev)
807 /* Disable controller */
808 __i2c_dw_enable(dev, false);
810 /* Disable all interupts */
811 dw_writel(dev, 0, DW_IC_INTR_MASK);
812 dw_readl(dev, DW_IC_CLR_INTR);
814 EXPORT_SYMBOL_GPL(i2c_dw_disable);
816 void i2c_dw_clear_int(struct dw_i2c_dev *dev)
818 dw_readl(dev, DW_IC_CLR_INTR);
820 EXPORT_SYMBOL_GPL(i2c_dw_clear_int);
822 void i2c_dw_disable_int(struct dw_i2c_dev *dev)
824 dw_writel(dev, 0, DW_IC_INTR_MASK);
826 EXPORT_SYMBOL_GPL(i2c_dw_disable_int);
828 u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev)
830 return dw_readl(dev, DW_IC_COMP_PARAM_1);
832 EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param);
834 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
835 MODULE_LICENSE("GPL");