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
104 #define STATUS_IDLE 0x0
105 #define STATUS_WRITE_IN_PROGRESS 0x1
106 #define STATUS_READ_IN_PROGRESS 0x2
108 #define TIMEOUT 20 /* ms */
111 * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register
113 * only expected abort codes are listed here
114 * refer to the datasheet for the full list
116 #define ABRT_7B_ADDR_NOACK 0
117 #define ABRT_10ADDR1_NOACK 1
118 #define ABRT_10ADDR2_NOACK 2
119 #define ABRT_TXDATA_NOACK 3
120 #define ABRT_GCALL_NOACK 4
121 #define ABRT_GCALL_READ 5
122 #define ABRT_SBYTE_ACKDET 7
123 #define ABRT_SBYTE_NORSTRT 9
124 #define ABRT_10B_RD_NORSTRT 10
125 #define ABRT_MASTER_DIS 11
128 #define DW_IC_TX_ABRT_7B_ADDR_NOACK (1UL << ABRT_7B_ADDR_NOACK)
129 #define DW_IC_TX_ABRT_10ADDR1_NOACK (1UL << ABRT_10ADDR1_NOACK)
130 #define DW_IC_TX_ABRT_10ADDR2_NOACK (1UL << ABRT_10ADDR2_NOACK)
131 #define DW_IC_TX_ABRT_TXDATA_NOACK (1UL << ABRT_TXDATA_NOACK)
132 #define DW_IC_TX_ABRT_GCALL_NOACK (1UL << ABRT_GCALL_NOACK)
133 #define DW_IC_TX_ABRT_GCALL_READ (1UL << ABRT_GCALL_READ)
134 #define DW_IC_TX_ABRT_SBYTE_ACKDET (1UL << ABRT_SBYTE_ACKDET)
135 #define DW_IC_TX_ABRT_SBYTE_NORSTRT (1UL << ABRT_SBYTE_NORSTRT)
136 #define DW_IC_TX_ABRT_10B_RD_NORSTRT (1UL << ABRT_10B_RD_NORSTRT)
137 #define DW_IC_TX_ABRT_MASTER_DIS (1UL << ABRT_MASTER_DIS)
138 #define DW_IC_TX_ARB_LOST (1UL << ARB_LOST)
140 #define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \
141 DW_IC_TX_ABRT_10ADDR1_NOACK | \
142 DW_IC_TX_ABRT_10ADDR2_NOACK | \
143 DW_IC_TX_ABRT_TXDATA_NOACK | \
144 DW_IC_TX_ABRT_GCALL_NOACK)
146 static char *abort_sources[] = {
147 [ABRT_7B_ADDR_NOACK] =
148 "slave address not acknowledged (7bit mode)",
149 [ABRT_10ADDR1_NOACK] =
150 "first address byte not acknowledged (10bit mode)",
151 [ABRT_10ADDR2_NOACK] =
152 "second address byte not acknowledged (10bit mode)",
153 [ABRT_TXDATA_NOACK] =
154 "data not acknowledged",
156 "no acknowledgement for a general call",
158 "read after general call",
159 [ABRT_SBYTE_ACKDET] =
160 "start byte acknowledged",
161 [ABRT_SBYTE_NORSTRT] =
162 "trying to send start byte when restart is disabled",
163 [ABRT_10B_RD_NORSTRT] =
164 "trying to read when restart is disabled (10bit mode)",
166 "trying to use disabled adapter",
171 u32 dw_readl(struct dw_i2c_dev *dev, int offset)
175 if (dev->accessor_flags & ACCESS_16BIT)
176 value = readw(dev->base + offset) |
177 (readw(dev->base + offset + 2) << 16);
179 value = readl(dev->base + offset);
181 if (dev->accessor_flags & ACCESS_SWAP)
182 return swab32(value);
187 void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
189 if (dev->accessor_flags & ACCESS_SWAP)
192 if (dev->accessor_flags & ACCESS_16BIT) {
193 writew((u16)b, dev->base + offset);
194 writew((u16)(b >> 16), dev->base + offset + 2);
196 writel(b, dev->base + offset);
201 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
204 * DesignWare I2C core doesn't seem to have solid strategy to meet
205 * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
206 * will result in violation of the tHD;STA spec.
210 * Conditional expression:
212 * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
214 * This is based on the DW manuals, and represents an ideal
215 * configuration. The resulting I2C bus speed will be
216 * faster than any of the others.
218 * If your hardware is free from tHD;STA issue, try this one.
220 return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
223 * Conditional expression:
225 * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
227 * This is just experimental rule; the tHD;STA period turned
228 * out to be proportinal to (_HCNT + 3). With this setting,
229 * we could meet both tHIGH and tHD;STA timing specs.
231 * If unsure, you'd better to take this alternative.
233 * The reason why we need to take into account "tf" here,
234 * is the same as described in i2c_dw_scl_lcnt().
236 return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
239 static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
242 * Conditional expression:
244 * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
246 * DW I2C core starts counting the SCL CNTs for the LOW period
247 * of the SCL clock (tLOW) as soon as it pulls the SCL line.
248 * In order to meet the tLOW timing spec, we need to take into
249 * account the fall time of SCL signal (tf). Default tf value
250 * should be 0.3 us, for safety.
252 return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
255 static void __i2c_dw_enable(struct dw_i2c_dev *dev, bool enable)
260 dw_writel(dev, enable, DW_IC_ENABLE);
261 if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == enable)
265 * Wait 10 times the signaling period of the highest I2C
266 * transfer supported by the driver (for 400KHz this is
267 * 25us) as described in the DesignWare I2C databook.
269 usleep_range(25, 250);
272 dev_warn(dev->dev, "timeout in %sabling adapter\n",
273 enable ? "en" : "dis");
277 * i2c_dw_init() - initialize the designware i2c master hardware
278 * @dev: device private data
280 * This functions configures and enables the I2C master.
281 * This function is called during I2C init function, and in case of timeout at
284 int i2c_dw_init(struct dw_i2c_dev *dev)
290 input_clock_khz = dev->get_clk_rate_khz(dev);
292 reg = dw_readl(dev, DW_IC_COMP_TYPE);
293 if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
294 /* Configure register endianess access */
295 dev->accessor_flags |= ACCESS_SWAP;
296 } else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
297 /* Configure register access mode 16bit */
298 dev->accessor_flags |= ACCESS_16BIT;
299 } else if (reg != DW_IC_COMP_TYPE_VALUE) {
300 dev_err(dev->dev, "Unknown Synopsys component type: "
305 /* Disable the adapter */
306 __i2c_dw_enable(dev, false);
308 /* set standard and fast speed deviders for high/low periods */
311 hcnt = i2c_dw_scl_hcnt(input_clock_khz,
312 40, /* tHD;STA = tHIGH = 4.0 us */
314 0, /* 0: DW default, 1: Ideal */
316 lcnt = i2c_dw_scl_lcnt(input_clock_khz,
317 47, /* tLOW = 4.7 us */
321 /* Allow platforms to specify the ideal HCNT and LCNT values */
322 if (dev->ss_hcnt && dev->ss_lcnt) {
326 dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
327 dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
328 dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
331 hcnt = i2c_dw_scl_hcnt(input_clock_khz,
332 6, /* tHD;STA = tHIGH = 0.6 us */
334 0, /* 0: DW default, 1: Ideal */
336 lcnt = i2c_dw_scl_lcnt(input_clock_khz,
337 13, /* tLOW = 1.3 us */
341 if (dev->fs_hcnt && dev->fs_lcnt) {
345 dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
346 dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
347 dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
349 /* Configure SDA Hold Time if required */
350 if (dev->sda_hold_time) {
351 reg = dw_readl(dev, DW_IC_COMP_VERSION);
352 if (reg >= DW_IC_SDA_HOLD_MIN_VERS)
353 dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
356 "Hardware too old to adjust SDA hold time.");
359 /* Configure Tx/Rx FIFO threshold levels */
360 dw_writel(dev, dev->tx_fifo_depth - 1, DW_IC_TX_TL);
361 dw_writel(dev, 0, DW_IC_RX_TL);
363 /* configure the i2c master */
364 dw_writel(dev, dev->master_cfg , DW_IC_CON);
367 EXPORT_SYMBOL_GPL(i2c_dw_init);
370 * Waiting for bus not busy
372 static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
374 int timeout = TIMEOUT;
376 while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
378 dev_warn(dev->dev, "timeout waiting for bus ready\n");
382 usleep_range(1000, 1100);
388 static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
390 struct i2c_msg *msgs = dev->msgs;
393 /* Disable the adapter */
394 __i2c_dw_enable(dev, false);
396 /* set the slave (target) address */
397 dw_writel(dev, msgs[dev->msg_write_idx].addr, DW_IC_TAR);
399 /* if the slave address is ten bit address, enable 10BITADDR */
400 ic_con = dw_readl(dev, DW_IC_CON);
401 if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
402 ic_con |= DW_IC_CON_10BITADDR_MASTER;
404 ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
405 dw_writel(dev, ic_con, DW_IC_CON);
407 /* Enable the adapter */
408 __i2c_dw_enable(dev, true);
410 /* Clear and enable interrupts */
411 i2c_dw_clear_int(dev);
412 dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK);
416 * Initiate (and continue) low level master read/write transaction.
417 * This function is only called from i2c_dw_isr, and pumping i2c_msg
418 * messages into the tx buffer. Even if the size of i2c_msg data is
419 * longer than the size of the tx buffer, it handles everything.
422 i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
424 struct i2c_msg *msgs = dev->msgs;
426 int tx_limit, rx_limit;
427 u32 addr = msgs[dev->msg_write_idx].addr;
428 u32 buf_len = dev->tx_buf_len;
429 u8 *buf = dev->tx_buf;
430 bool need_restart = false;
432 intr_mask = DW_IC_INTR_DEFAULT_MASK;
434 for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
436 * if target address has changed, we need to
437 * reprogram the target address in the i2c
438 * adapter when we are done with this transfer
440 if (msgs[dev->msg_write_idx].addr != addr) {
442 "%s: invalid target address\n", __func__);
443 dev->msg_err = -EINVAL;
447 if (msgs[dev->msg_write_idx].len == 0) {
449 "%s: invalid message length\n", __func__);
450 dev->msg_err = -EINVAL;
454 if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
456 buf = msgs[dev->msg_write_idx].buf;
457 buf_len = msgs[dev->msg_write_idx].len;
459 /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and
460 * IC_RESTART_EN are set, we must manually
461 * set restart bit between messages.
463 if ((dev->master_cfg & DW_IC_CON_RESTART_EN) &&
464 (dev->msg_write_idx > 0))
468 tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
469 rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
471 while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
475 * If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must
476 * manually set the stop bit. However, it cannot be
477 * detected from the registers so we set it always
478 * when writing/reading the last byte.
480 if (dev->msg_write_idx == dev->msgs_num - 1 &&
486 need_restart = false;
489 if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
491 /* avoid rx buffer overrun */
492 if (rx_limit - dev->rx_outstanding <= 0)
495 dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
497 dev->rx_outstanding++;
499 dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
500 tx_limit--; buf_len--;
504 dev->tx_buf_len = buf_len;
507 /* more bytes to be written */
508 dev->status |= STATUS_WRITE_IN_PROGRESS;
511 dev->status &= ~STATUS_WRITE_IN_PROGRESS;
515 * If i2c_msg index search is completed, we don't need TX_EMPTY
516 * interrupt any more.
518 if (dev->msg_write_idx == dev->msgs_num)
519 intr_mask &= ~DW_IC_INTR_TX_EMPTY;
524 dw_writel(dev, intr_mask, DW_IC_INTR_MASK);
528 i2c_dw_read(struct dw_i2c_dev *dev)
530 struct i2c_msg *msgs = dev->msgs;
533 for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
537 if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
540 if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
541 len = msgs[dev->msg_read_idx].len;
542 buf = msgs[dev->msg_read_idx].buf;
544 len = dev->rx_buf_len;
548 rx_valid = dw_readl(dev, DW_IC_RXFLR);
550 for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
551 *buf++ = dw_readl(dev, DW_IC_DATA_CMD);
552 dev->rx_outstanding--;
556 dev->status |= STATUS_READ_IN_PROGRESS;
557 dev->rx_buf_len = len;
561 dev->status &= ~STATUS_READ_IN_PROGRESS;
565 static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
567 unsigned long abort_source = dev->abort_source;
570 if (abort_source & DW_IC_TX_ABRT_NOACK) {
571 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
573 "%s: %s\n", __func__, abort_sources[i]);
577 for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
578 dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
580 if (abort_source & DW_IC_TX_ARB_LOST)
582 else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
583 return -EINVAL; /* wrong msgs[] data */
589 * Prepare controller for a transaction and call i2c_dw_xfer_msg
592 i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
594 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
597 dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
599 mutex_lock(&dev->lock);
600 pm_runtime_get_sync(dev->dev);
602 INIT_COMPLETION(dev->cmd_complete);
606 dev->msg_write_idx = 0;
607 dev->msg_read_idx = 0;
609 dev->status = STATUS_IDLE;
610 dev->abort_source = 0;
611 dev->rx_outstanding = 0;
613 ret = i2c_dw_wait_bus_not_busy(dev);
617 /* start the transfers */
618 i2c_dw_xfer_init(dev);
620 /* wait for tx to complete */
621 ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);
623 dev_err(dev->dev, "controller timed out\n");
624 /* i2c_dw_init implicitly disables the adapter */
631 * We must disable the adapter before unlocking the &dev->lock mutex
632 * below. Otherwise the hardware might continue generating interrupts
633 * which in turn causes a race condition with the following transfer.
634 * Needs some more investigation if the additional interrupts are
635 * a hardware bug or this driver doesn't handle them correctly yet.
637 __i2c_dw_enable(dev, false);
645 if (likely(!dev->cmd_err)) {
650 /* We have an error */
651 if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
652 ret = i2c_dw_handle_tx_abort(dev);
658 pm_runtime_mark_last_busy(dev->dev);
659 pm_runtime_put_autosuspend(dev->dev);
660 mutex_unlock(&dev->lock);
664 EXPORT_SYMBOL_GPL(i2c_dw_xfer);
666 u32 i2c_dw_func(struct i2c_adapter *adap)
668 struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
669 return dev->functionality;
671 EXPORT_SYMBOL_GPL(i2c_dw_func);
673 static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
678 * The IC_INTR_STAT register just indicates "enabled" interrupts.
679 * Ths unmasked raw version of interrupt status bits are available
680 * in the IC_RAW_INTR_STAT register.
683 * stat = dw_readl(IC_INTR_STAT);
685 * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
687 * The raw version might be useful for debugging purposes.
689 stat = dw_readl(dev, DW_IC_INTR_STAT);
692 * Do not use the IC_CLR_INTR register to clear interrupts, or
693 * you'll miss some interrupts, triggered during the period from
694 * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
696 * Instead, use the separately-prepared IC_CLR_* registers.
698 if (stat & DW_IC_INTR_RX_UNDER)
699 dw_readl(dev, DW_IC_CLR_RX_UNDER);
700 if (stat & DW_IC_INTR_RX_OVER)
701 dw_readl(dev, DW_IC_CLR_RX_OVER);
702 if (stat & DW_IC_INTR_TX_OVER)
703 dw_readl(dev, DW_IC_CLR_TX_OVER);
704 if (stat & DW_IC_INTR_RD_REQ)
705 dw_readl(dev, DW_IC_CLR_RD_REQ);
706 if (stat & DW_IC_INTR_TX_ABRT) {
708 * The IC_TX_ABRT_SOURCE register is cleared whenever
709 * the IC_CLR_TX_ABRT is read. Preserve it beforehand.
711 dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
712 dw_readl(dev, DW_IC_CLR_TX_ABRT);
714 if (stat & DW_IC_INTR_RX_DONE)
715 dw_readl(dev, DW_IC_CLR_RX_DONE);
716 if (stat & DW_IC_INTR_ACTIVITY)
717 dw_readl(dev, DW_IC_CLR_ACTIVITY);
718 if (stat & DW_IC_INTR_STOP_DET)
719 dw_readl(dev, DW_IC_CLR_STOP_DET);
720 if (stat & DW_IC_INTR_START_DET)
721 dw_readl(dev, DW_IC_CLR_START_DET);
722 if (stat & DW_IC_INTR_GEN_CALL)
723 dw_readl(dev, DW_IC_CLR_GEN_CALL);
729 * Interrupt service routine. This gets called whenever an I2C interrupt
732 irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
734 struct dw_i2c_dev *dev = dev_id;
737 enabled = dw_readl(dev, DW_IC_ENABLE);
738 stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
739 dev_dbg(dev->dev, "%s: %s enabled= 0x%x stat=0x%x\n", __func__,
740 dev->adapter.name, enabled, stat);
741 if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
744 stat = i2c_dw_read_clear_intrbits(dev);
746 if (stat & DW_IC_INTR_TX_ABRT) {
747 dev->cmd_err |= DW_IC_ERR_TX_ABRT;
748 dev->status = STATUS_IDLE;
751 * Anytime TX_ABRT is set, the contents of the tx/rx
752 * buffers are flushed. Make sure to skip them.
754 dw_writel(dev, 0, DW_IC_INTR_MASK);
758 if (stat & DW_IC_INTR_RX_FULL)
761 if (stat & DW_IC_INTR_TX_EMPTY)
762 i2c_dw_xfer_msg(dev);
765 * No need to modify or disable the interrupt mask here.
766 * i2c_dw_xfer_msg() will take care of it according to
767 * the current transmit status.
771 if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err)
772 complete(&dev->cmd_complete);
776 EXPORT_SYMBOL_GPL(i2c_dw_isr);
778 void i2c_dw_enable(struct dw_i2c_dev *dev)
780 /* Enable the adapter */
781 __i2c_dw_enable(dev, true);
783 EXPORT_SYMBOL_GPL(i2c_dw_enable);
785 u32 i2c_dw_is_enabled(struct dw_i2c_dev *dev)
787 return dw_readl(dev, DW_IC_ENABLE);
789 EXPORT_SYMBOL_GPL(i2c_dw_is_enabled);
791 void i2c_dw_disable(struct dw_i2c_dev *dev)
793 /* Disable controller */
794 __i2c_dw_enable(dev, false);
796 /* Disable all interupts */
797 dw_writel(dev, 0, DW_IC_INTR_MASK);
798 dw_readl(dev, DW_IC_CLR_INTR);
800 EXPORT_SYMBOL_GPL(i2c_dw_disable);
802 void i2c_dw_clear_int(struct dw_i2c_dev *dev)
804 dw_readl(dev, DW_IC_CLR_INTR);
806 EXPORT_SYMBOL_GPL(i2c_dw_clear_int);
808 void i2c_dw_disable_int(struct dw_i2c_dev *dev)
810 dw_writel(dev, 0, DW_IC_INTR_MASK);
812 EXPORT_SYMBOL_GPL(i2c_dw_disable_int);
814 u32 i2c_dw_read_comp_param(struct dw_i2c_dev *dev)
816 return dw_readl(dev, DW_IC_COMP_PARAM_1);
818 EXPORT_SYMBOL_GPL(i2c_dw_read_comp_param);
820 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
821 MODULE_LICENSE("GPL");