1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (c) 2014 Linaro Ltd.
4 * Copyright (c) 2014 Hisilicon Limited.
6 * Now only support 7 bit address.
10 #include <linux/delay.h>
11 #include <linux/i2c.h>
13 #include <linux/interrupt.h>
14 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/pm_runtime.h>
20 #define HIX5I2C_CTRL 0x00
21 #define HIX5I2C_COM 0x04
22 #define HIX5I2C_ICR 0x08
23 #define HIX5I2C_SR 0x0c
24 #define HIX5I2C_SCL_H 0x10
25 #define HIX5I2C_SCL_L 0x14
26 #define HIX5I2C_TXR 0x18
27 #define HIX5I2C_RXR 0x1c
30 #define I2C_ENABLE BIT(8)
31 #define I2C_UNMASK_TOTAL BIT(7)
32 #define I2C_UNMASK_START BIT(6)
33 #define I2C_UNMASK_END BIT(5)
34 #define I2C_UNMASK_SEND BIT(4)
35 #define I2C_UNMASK_RECEIVE BIT(3)
36 #define I2C_UNMASK_ACK BIT(2)
37 #define I2C_UNMASK_ARBITRATE BIT(1)
38 #define I2C_UNMASK_OVER BIT(0)
39 #define I2C_UNMASK_ALL (I2C_UNMASK_ACK | I2C_UNMASK_OVER)
42 #define I2C_NO_ACK BIT(4)
43 #define I2C_START BIT(3)
44 #define I2C_READ BIT(2)
45 #define I2C_WRITE BIT(1)
46 #define I2C_STOP BIT(0)
49 #define I2C_CLEAR_START BIT(6)
50 #define I2C_CLEAR_END BIT(5)
51 #define I2C_CLEAR_SEND BIT(4)
52 #define I2C_CLEAR_RECEIVE BIT(3)
53 #define I2C_CLEAR_ACK BIT(2)
54 #define I2C_CLEAR_ARBITRATE BIT(1)
55 #define I2C_CLEAR_OVER BIT(0)
56 #define I2C_CLEAR_ALL (I2C_CLEAR_START | I2C_CLEAR_END | \
57 I2C_CLEAR_SEND | I2C_CLEAR_RECEIVE | \
58 I2C_CLEAR_ACK | I2C_CLEAR_ARBITRATE | \
62 #define I2C_BUSY BIT(7)
63 #define I2C_START_INTR BIT(6)
64 #define I2C_END_INTR BIT(5)
65 #define I2C_SEND_INTR BIT(4)
66 #define I2C_RECEIVE_INTR BIT(3)
67 #define I2C_ACK_INTR BIT(2)
68 #define I2C_ARBITRATE_INTR BIT(1)
69 #define I2C_OVER_INTR BIT(0)
71 #define HIX5I2C_MAX_FREQ 400000 /* 400k */
73 enum hix5hd2_i2c_state {
74 HIX5I2C_STAT_RW_ERR = -1,
77 HIX5I2C_STAT_SND_STOP,
78 HIX5I2C_STAT_RW_SUCCESS,
81 struct hix5hd2_i2c_priv {
82 struct i2c_adapter adap;
84 struct completion msg_complete;
91 spinlock_t lock; /* IRQ synchronization */
94 enum hix5hd2_i2c_state state;
97 static u32 hix5hd2_i2c_clr_pend_irq(struct hix5hd2_i2c_priv *priv)
99 u32 val = readl_relaxed(priv->regs + HIX5I2C_SR);
101 writel_relaxed(val, priv->regs + HIX5I2C_ICR);
106 static void hix5hd2_i2c_clr_all_irq(struct hix5hd2_i2c_priv *priv)
108 writel_relaxed(I2C_CLEAR_ALL, priv->regs + HIX5I2C_ICR);
111 static void hix5hd2_i2c_disable_irq(struct hix5hd2_i2c_priv *priv)
113 writel_relaxed(0, priv->regs + HIX5I2C_CTRL);
116 static void hix5hd2_i2c_enable_irq(struct hix5hd2_i2c_priv *priv)
118 writel_relaxed(I2C_ENABLE | I2C_UNMASK_TOTAL | I2C_UNMASK_ALL,
119 priv->regs + HIX5I2C_CTRL);
122 static void hix5hd2_i2c_drv_setrate(struct hix5hd2_i2c_priv *priv)
127 /* close all i2c interrupt */
128 val = readl_relaxed(priv->regs + HIX5I2C_CTRL);
129 writel_relaxed(val & (~I2C_UNMASK_TOTAL), priv->regs + HIX5I2C_CTRL);
132 sysclock = clk_get_rate(priv->clk);
133 scl = (sysclock / (rate * 2)) / 2 - 1;
134 writel_relaxed(scl, priv->regs + HIX5I2C_SCL_H);
135 writel_relaxed(scl, priv->regs + HIX5I2C_SCL_L);
137 /* restore original interrupt*/
138 writel_relaxed(val, priv->regs + HIX5I2C_CTRL);
140 dev_dbg(priv->dev, "%s: sysclock=%d, rate=%d, scl=%d\n",
141 __func__, sysclock, rate, scl);
144 static void hix5hd2_i2c_init(struct hix5hd2_i2c_priv *priv)
146 hix5hd2_i2c_disable_irq(priv);
147 hix5hd2_i2c_drv_setrate(priv);
148 hix5hd2_i2c_clr_all_irq(priv);
149 hix5hd2_i2c_enable_irq(priv);
152 static void hix5hd2_i2c_reset(struct hix5hd2_i2c_priv *priv)
154 clk_disable_unprepare(priv->clk);
156 clk_prepare_enable(priv->clk);
157 hix5hd2_i2c_init(priv);
160 static int hix5hd2_i2c_wait_bus_idle(struct hix5hd2_i2c_priv *priv)
162 unsigned long stop_time;
165 /* wait for 100 milli seconds for the bus to be idle */
166 stop_time = jiffies + msecs_to_jiffies(100);
168 int_status = hix5hd2_i2c_clr_pend_irq(priv);
169 if (!(int_status & I2C_BUSY))
172 usleep_range(50, 200);
173 } while (time_before(jiffies, stop_time));
178 static void hix5hd2_rw_over(struct hix5hd2_i2c_priv *priv)
180 if (priv->state == HIX5I2C_STAT_SND_STOP)
181 dev_dbg(priv->dev, "%s: rw and send stop over\n", __func__);
183 dev_dbg(priv->dev, "%s: have not data to send\n", __func__);
185 priv->state = HIX5I2C_STAT_RW_SUCCESS;
189 static void hix5hd2_rw_handle_stop(struct hix5hd2_i2c_priv *priv)
192 priv->state = HIX5I2C_STAT_SND_STOP;
193 writel_relaxed(I2C_STOP, priv->regs + HIX5I2C_COM);
195 hix5hd2_rw_over(priv);
199 static void hix5hd2_read_handle(struct hix5hd2_i2c_priv *priv)
201 if (priv->msg_len == 1) {
202 /* the last byte don't need send ACK */
203 writel_relaxed(I2C_READ | I2C_NO_ACK, priv->regs + HIX5I2C_COM);
204 } else if (priv->msg_len > 1) {
205 /* if i2c master receive data will send ACK */
206 writel_relaxed(I2C_READ, priv->regs + HIX5I2C_COM);
208 hix5hd2_rw_handle_stop(priv);
212 static void hix5hd2_write_handle(struct hix5hd2_i2c_priv *priv)
216 if (priv->msg_len > 0) {
217 data = priv->msg->buf[priv->msg_idx++];
218 writel_relaxed(data, priv->regs + HIX5I2C_TXR);
219 writel_relaxed(I2C_WRITE, priv->regs + HIX5I2C_COM);
221 hix5hd2_rw_handle_stop(priv);
225 static int hix5hd2_rw_preprocess(struct hix5hd2_i2c_priv *priv)
229 if (priv->state == HIX5I2C_STAT_INIT) {
230 priv->state = HIX5I2C_STAT_RW;
231 } else if (priv->state == HIX5I2C_STAT_RW) {
232 if (priv->msg->flags & I2C_M_RD) {
233 data = readl_relaxed(priv->regs + HIX5I2C_RXR);
234 priv->msg->buf[priv->msg_idx++] = data;
238 dev_dbg(priv->dev, "%s: error: priv->state = %d, msg_len = %d\n",
239 __func__, priv->state, priv->msg_len);
245 static irqreturn_t hix5hd2_i2c_irq(int irqno, void *dev_id)
247 struct hix5hd2_i2c_priv *priv = dev_id;
251 spin_lock(&priv->lock);
253 int_status = hix5hd2_i2c_clr_pend_irq(priv);
256 if (int_status & I2C_ARBITRATE_INTR) {
258 dev_dbg(priv->dev, "ARB bus loss\n");
260 priv->state = HIX5I2C_STAT_RW_ERR;
262 } else if (int_status & I2C_ACK_INTR) {
264 dev_dbg(priv->dev, "No ACK from device\n");
266 priv->state = HIX5I2C_STAT_RW_ERR;
270 if (int_status & I2C_OVER_INTR) {
271 if (priv->msg_len > 0) {
272 ret = hix5hd2_rw_preprocess(priv);
275 priv->state = HIX5I2C_STAT_RW_ERR;
278 if (priv->msg->flags & I2C_M_RD)
279 hix5hd2_read_handle(priv);
281 hix5hd2_write_handle(priv);
283 hix5hd2_rw_over(priv);
288 if ((priv->state == HIX5I2C_STAT_RW_SUCCESS &&
289 priv->msg->len == priv->msg_idx) ||
290 (priv->state == HIX5I2C_STAT_RW_ERR)) {
291 hix5hd2_i2c_disable_irq(priv);
292 hix5hd2_i2c_clr_pend_irq(priv);
293 complete(&priv->msg_complete);
296 spin_unlock(&priv->lock);
301 static void hix5hd2_i2c_message_start(struct hix5hd2_i2c_priv *priv, int stop)
305 spin_lock_irqsave(&priv->lock, flags);
306 hix5hd2_i2c_clr_all_irq(priv);
307 hix5hd2_i2c_enable_irq(priv);
309 writel_relaxed(i2c_8bit_addr_from_msg(priv->msg),
310 priv->regs + HIX5I2C_TXR);
312 writel_relaxed(I2C_WRITE | I2C_START, priv->regs + HIX5I2C_COM);
313 spin_unlock_irqrestore(&priv->lock, flags);
316 static int hix5hd2_i2c_xfer_msg(struct hix5hd2_i2c_priv *priv,
317 struct i2c_msg *msgs, int stop)
319 unsigned long timeout;
324 priv->msg_len = priv->msg->len;
327 priv->state = HIX5I2C_STAT_INIT;
329 reinit_completion(&priv->msg_complete);
330 hix5hd2_i2c_message_start(priv, stop);
332 timeout = wait_for_completion_timeout(&priv->msg_complete,
335 priv->state = HIX5I2C_STAT_RW_ERR;
336 priv->err = -ETIMEDOUT;
337 dev_warn(priv->dev, "%s timeout=%d\n",
338 msgs->flags & I2C_M_RD ? "rx" : "tx",
344 * If this is the last message to be transfered (stop == 1)
345 * Then check if the bus can be brought back to idle.
347 if (priv->state == HIX5I2C_STAT_RW_SUCCESS && stop)
348 ret = hix5hd2_i2c_wait_bus_idle(priv);
351 hix5hd2_i2c_reset(priv);
356 static int hix5hd2_i2c_xfer(struct i2c_adapter *adap,
357 struct i2c_msg *msgs, int num)
359 struct hix5hd2_i2c_priv *priv = i2c_get_adapdata(adap);
362 pm_runtime_get_sync(priv->dev);
364 for (i = 0; i < num; i++, msgs++) {
365 stop = (i == num - 1);
366 ret = hix5hd2_i2c_xfer_msg(priv, msgs, stop);
374 pm_runtime_mark_last_busy(priv->dev);
375 pm_runtime_put_autosuspend(priv->dev);
379 static u32 hix5hd2_i2c_func(struct i2c_adapter *adap)
381 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
384 static const struct i2c_algorithm hix5hd2_i2c_algorithm = {
385 .master_xfer = hix5hd2_i2c_xfer,
386 .functionality = hix5hd2_i2c_func,
389 static int hix5hd2_i2c_probe(struct platform_device *pdev)
391 struct device_node *np = pdev->dev.of_node;
392 struct hix5hd2_i2c_priv *priv;
393 struct resource *mem;
397 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
401 if (of_property_read_u32(np, "clock-frequency", &freq)) {
402 /* use 100k as default value */
405 if (freq > HIX5I2C_MAX_FREQ) {
406 priv->freq = HIX5I2C_MAX_FREQ;
407 dev_warn(priv->dev, "use max freq %d instead\n",
414 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
415 priv->regs = devm_ioremap_resource(&pdev->dev, mem);
416 if (IS_ERR(priv->regs))
417 return PTR_ERR(priv->regs);
419 irq = platform_get_irq(pdev, 0);
421 dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
425 priv->clk = devm_clk_get(&pdev->dev, NULL);
426 if (IS_ERR(priv->clk)) {
427 dev_err(&pdev->dev, "cannot get clock\n");
428 return PTR_ERR(priv->clk);
430 clk_prepare_enable(priv->clk);
432 strlcpy(priv->adap.name, "hix5hd2-i2c", sizeof(priv->adap.name));
433 priv->dev = &pdev->dev;
434 priv->adap.owner = THIS_MODULE;
435 priv->adap.algo = &hix5hd2_i2c_algorithm;
436 priv->adap.retries = 3;
437 priv->adap.dev.of_node = np;
438 priv->adap.algo_data = priv;
439 priv->adap.dev.parent = &pdev->dev;
440 i2c_set_adapdata(&priv->adap, priv);
441 platform_set_drvdata(pdev, priv);
442 spin_lock_init(&priv->lock);
443 init_completion(&priv->msg_complete);
445 hix5hd2_i2c_init(priv);
447 ret = devm_request_irq(&pdev->dev, irq, hix5hd2_i2c_irq,
448 IRQF_NO_SUSPEND, dev_name(&pdev->dev), priv);
450 dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", irq);
454 pm_runtime_set_autosuspend_delay(priv->dev, MSEC_PER_SEC);
455 pm_runtime_use_autosuspend(priv->dev);
456 pm_runtime_set_active(priv->dev);
457 pm_runtime_enable(priv->dev);
459 ret = i2c_add_adapter(&priv->adap);
466 pm_runtime_disable(priv->dev);
467 pm_runtime_set_suspended(priv->dev);
469 clk_disable_unprepare(priv->clk);
473 static int hix5hd2_i2c_remove(struct platform_device *pdev)
475 struct hix5hd2_i2c_priv *priv = platform_get_drvdata(pdev);
477 i2c_del_adapter(&priv->adap);
478 pm_runtime_disable(priv->dev);
479 pm_runtime_set_suspended(priv->dev);
480 clk_disable_unprepare(priv->clk);
486 static int hix5hd2_i2c_runtime_suspend(struct device *dev)
488 struct hix5hd2_i2c_priv *priv = dev_get_drvdata(dev);
490 clk_disable_unprepare(priv->clk);
495 static int hix5hd2_i2c_runtime_resume(struct device *dev)
497 struct hix5hd2_i2c_priv *priv = dev_get_drvdata(dev);
499 clk_prepare_enable(priv->clk);
500 hix5hd2_i2c_init(priv);
506 static const struct dev_pm_ops hix5hd2_i2c_pm_ops = {
507 SET_RUNTIME_PM_OPS(hix5hd2_i2c_runtime_suspend,
508 hix5hd2_i2c_runtime_resume,
512 static const struct of_device_id hix5hd2_i2c_match[] = {
513 { .compatible = "hisilicon,hix5hd2-i2c" },
516 MODULE_DEVICE_TABLE(of, hix5hd2_i2c_match);
518 static struct platform_driver hix5hd2_i2c_driver = {
519 .probe = hix5hd2_i2c_probe,
520 .remove = hix5hd2_i2c_remove,
522 .name = "hix5hd2-i2c",
523 .pm = &hix5hd2_i2c_pm_ops,
524 .of_match_table = hix5hd2_i2c_match,
528 module_platform_driver(hix5hd2_i2c_driver);
530 MODULE_DESCRIPTION("Hix5hd2 I2C Bus driver");
531 MODULE_AUTHOR("Wei Yan <sledge.yanwei@huawei.com>");
532 MODULE_LICENSE("GPL");
533 MODULE_ALIAS("platform:hix5hd2-i2c");