i2c/busses/i2c-axxia.c

154 static void i2c_int_disable(struct axxia_i2c_dev *idev, u32 mask)
158 	int_en = readl(idev->base + MST_INT_ENABLE);
159 	writel(int_en & ~mask, idev->base + MST_INT_ENABLE);
162 static void i2c_int_enable(struct axxia_i2c_dev *idev, u32 mask)
166 	int_en = readl(idev->base + MST_INT_ENABLE);
167 	writel(int_en | mask, idev->base + MST_INT_ENABLE);
178 static int axxia_i2c_init(struct axxia_i2c_dev *idev)
180 	u32 divisor = clk_get_rate(idev->i2c_clk) / idev->bus_clk_rate;
181 	u32 clk_mhz = clk_get_rate(idev->i2c_clk) / 1000000;
188 	dev_dbg(idev->dev, "rate=%uHz per_clk=%uMHz -> ratio=1:%u\n",
189 		idev->bus_clk_rate, clk_mhz, divisor);
192 	writel(0x01, idev->base + SOFT_RESET);
194 	while (readl(idev->base + SOFT_RESET) & 1) {
196 			dev_warn(idev->dev, "Soft reset failed\n");
202 	writel(0x1, idev->base + GLOBAL_CONTROL);
204 	if (idev->bus_clk_rate <= I2C_MAX_STANDARD_MODE_FREQ) {
217 	writel(t_high, idev->base + SCL_HIGH_PERIOD);
219 	writel(t_low, idev->base + SCL_LOW_PERIOD);
221 	writel(t_setup, idev->base + SDA_SETUP_TIME);
223 	writel(ns_to_clk(300, clk_mhz), idev->base + SDA_HOLD_TIME);
225 	writel(ns_to_clk(50, clk_mhz), idev->base + SPIKE_FLTR_LEN);
240 	writel(prescale, idev->base + TIMER_CLOCK_DIV);
242 	writel(WT_EN | WT_VALUE(tmo_clk), idev->base + WAIT_TIMER_CONTROL);
245 	i2c_int_disable(idev, ~0);
248 	writel(0x01, idev->base + INTERRUPT_ENABLE);
267 static int axxia_i2c_empty_rx_fifo(struct axxia_i2c_dev *idev)
269 	struct i2c_msg *msg = idev->msg_r;
270 	size_t rx_fifo_avail = readl(idev->base + MST_RX_FIFO);
271 	int bytes_to_transfer = min(rx_fifo_avail, msg->len - idev->msg_xfrd_r);
274 		int c = readl(idev->base + MST_DATA);
276 		if (idev->msg_xfrd_r == 0 && i2c_m_recv_len(msg)) {
281 				idev->msg_err = -EPROTO;
282 				i2c_int_disable(idev, ~MST_STATUS_TSS);
283 				complete(&idev->msg_complete);
287 			writel(msg->len, idev->base + MST_RX_XFER);
289 		msg->buf[idev->msg_xfrd_r++] = c;
299 static int axxia_i2c_fill_tx_fifo(struct axxia_i2c_dev *idev)
301 	struct i2c_msg *msg = idev->msg;
302 	size_t tx_fifo_avail = FIFO_SIZE - readl(idev->base + MST_TX_FIFO);
303 	int bytes_to_transfer = min(tx_fifo_avail, msg->len - idev->msg_xfrd);
304 	int ret = msg->len - idev->msg_xfrd - bytes_to_transfer;
307 		writel(msg->buf[idev->msg_xfrd++], idev->base + MST_DATA);
312 static void axxia_i2c_slv_fifo_event(struct axxia_i2c_dev *idev)
314 	u32 fifo_status = readl(idev->base + SLV_RX_FIFO);
317 	dev_dbg(idev->dev, "slave irq fifo_status=0x%x\n", fifo_status);
321 			i2c_slave_event(idev->slave,
324 		val = readl(idev->base + SLV_DATA);
325 		i2c_slave_event(idev->slave, I2C_SLAVE_WRITE_RECEIVED, &val);
328 		readl(idev->base + SLV_DATA); /* dummy read */
329 		i2c_slave_event(idev->slave, I2C_SLAVE_STOP, &val);
332 		readl(idev->base + SLV_DATA); /* dummy read */
335 static irqreturn_t axxia_i2c_slv_isr(struct axxia_i2c_dev *idev)
337 	u32 status = readl(idev->base + SLV_INT_STATUS);
340 	dev_dbg(idev->dev, "slave irq status=0x%x\n", status);
343 		axxia_i2c_slv_fifo_event(idev);
345 		i2c_slave_event(idev->slave, I2C_SLAVE_READ_REQUESTED, &val);
346 		writel(val, idev->base + SLV_DATA);
349 		i2c_slave_event(idev->slave, I2C_SLAVE_READ_PROCESSED, &val);
350 		writel(val, idev->base + SLV_DATA);
353 		i2c_slave_event(idev->slave, I2C_SLAVE_STOP, &val);
355 	writel(INT_SLV, idev->base + INTERRUPT_STATUS);
361 	struct axxia_i2c_dev *idev = _dev;
365 	status = readl(idev->base + INTERRUPT_STATUS);
368 		ret = axxia_i2c_slv_isr(idev);
373 	status = readl(idev->base + MST_INT_STATUS);
375 	if (!idev->msg) {
376 		dev_warn(idev->dev, "unexpected interrupt\n");
381 	if (i2c_m_rd(idev->msg_r) && (status & MST_STATUS_RFL))
382 		axxia_i2c_empty_rx_fifo(idev);
385 	if (!i2c_m_rd(idev->msg) && (status & MST_STATUS_TFL)) {
386 		if (axxia_i2c_fill_tx_fifo(idev) == 0)
387 			i2c_int_disable(idev, MST_STATUS_TFL);
392 		i2c_int_disable(idev, ~0);
394 			idev->msg_err = -EAGAIN;
396 			idev->msg_err = -ENXIO;
398 			idev->msg_err = -EIO;
399 		dev_dbg(idev->dev, "error %#x, addr=%#x rx=%u/%u tx=%u/%u\n",
401 			idev->msg->addr,
402 			readl(idev->base + MST_RX_BYTES_XFRD),
403 			readl(idev->base + MST_RX_XFER),
404 			readl(idev->base + MST_TX_BYTES_XFRD),
405 			readl(idev->base + MST_TX_XFER));
406 		complete(&idev->msg_complete);
409 		i2c_int_disable(idev, ~MST_STATUS_TSS);
410 		complete(&idev->msg_complete);
413 		int mask = idev->last ? ~0 : ~MST_STATUS_TSS;
415 		i2c_int_disable(idev, mask);
416 		if (i2c_m_rd(idev->msg_r) && idev->msg_xfrd_r < idev->msg_r->len)
417 			axxia_i2c_empty_rx_fifo(idev);
418 		complete(&idev->msg_complete);
421 		idev->msg_err = -ETIMEDOUT;
422 		i2c_int_disable(idev, ~MST_STATUS_TSS);
423 		complete(&idev->msg_complete);
428 	writel(INT_MST, idev->base + INTERRUPT_STATUS);
433 static void axxia_i2c_set_addr(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
445 	writel(addr_1, idev->base + MST_ADDR_1);
446 	writel(addr_2, idev->base + MST_ADDR_2);
453 static int axxia_i2c_handle_seq_nak(struct axxia_i2c_dev *idev)
458 		if ((readl(idev->base + MST_COMMAND) & CMD_BUSY) == 0)
466 static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
472 	axxia_i2c_set_addr(idev, &msgs[0]);
474 	writel(msgs[0].len, idev->base + MST_TX_XFER);
475 	writel(rlen, idev->base + MST_RX_XFER);
477 	idev->msg = &msgs[0];
478 	idev->msg_r = &msgs[1];
479 	idev->msg_xfrd = 0;
480 	idev->msg_xfrd_r = 0;
481 	idev->last = true;
482 	axxia_i2c_fill_tx_fifo(idev);
484 	writel(CMD_SEQUENCE, idev->base + MST_COMMAND);
486 	reinit_completion(&idev->msg_complete);
487 	i2c_int_enable(idev, int_mask);
489 	time_left = wait_for_completion_timeout(&idev->msg_complete,
492 	if (idev->msg_err == -ENXIO) {
493 		if (axxia_i2c_handle_seq_nak(idev))
494 			axxia_i2c_init(idev);
495 	} else if (readl(idev->base + MST_COMMAND) & CMD_BUSY) {
496 		dev_warn(idev->dev, "busy after xfer\n");
500 		idev->msg_err = -ETIMEDOUT;
501 		i2c_recover_bus(&idev->adapter);
502 		axxia_i2c_init(idev);
505 	if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO)
506 		axxia_i2c_init(idev);
508 	return idev->msg_err;
511 static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg,
519 	idev->msg = msg;
520 	idev->msg_r = msg;
521 	idev->msg_xfrd = 0;
522 	idev->msg_xfrd_r = 0;
523 	idev->last = last;
524 	reinit_completion(&idev->msg_complete);
526 	axxia_i2c_set_addr(idev, msg);
538 	writel(rx_xfer, idev->base + MST_RX_XFER);
539 	writel(tx_xfer, idev->base + MST_TX_XFER);
543 	else if (axxia_i2c_fill_tx_fifo(idev) != 0)
546 	wt_value = WT_VALUE(readl(idev->base + WAIT_TIMER_CONTROL));
548 	writel(wt_value, idev->base + WAIT_TIMER_CONTROL);
550 	if (idev->msg_err)
554 		writel(CMD_MANUAL, idev->base + MST_COMMAND);
557 		writel(CMD_AUTO, idev->base + MST_COMMAND);
561 	writel(WT_EN | wt_value, idev->base + WAIT_TIMER_CONTROL);
563 	i2c_int_enable(idev, int_mask);
565 	time_left = wait_for_completion_timeout(&idev->msg_complete,
568 	i2c_int_disable(idev, int_mask);
570 	if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
571 		dev_warn(idev->dev, "busy after xfer\n");
574 		idev->msg_err = -ETIMEDOUT;
575 		i2c_recover_bus(&idev->adapter);
576 		axxia_i2c_init(idev);
580 	if (unlikely(idev->msg_err) && idev->msg_err != -ENXIO &&
581 			idev->msg_err != -ETIMEDOUT)
582 		axxia_i2c_init(idev);
584 	return idev->msg_err;
602 	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
606 	idev->msg_err = 0;
609 		ret = axxia_i2c_xfer_seq(idev, msgs);
613 	i2c_int_enable(idev, MST_STATUS_TSS);
616 		ret = axxia_i2c_xfer_msg(idev, &msgs[i], i == (num - 1));
623 	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
625 	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SCLS);
630 	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
634 	tmp = readl(idev->base + I2C_BUS_MONITOR) & BM_SDAC;
637 	writel(tmp, idev->base + I2C_BUS_MONITOR);
642 	struct axxia_i2c_dev *idev = i2c_get_adapdata(adap);
644 	return !!(readl(idev->base + I2C_BUS_MONITOR) & BM_SDAS);
663 	struct axxia_i2c_dev *idev = i2c_get_adapdata(slave->adapter);
667 	if (idev->slave)
670 	idev->slave = slave;
673 	writel(GLOBAL_MST_EN | GLOBAL_SLV_EN, idev->base + GLOBAL_CONTROL);
674 	writel(INT_MST | INT_SLV, idev->base + INTERRUPT_ENABLE);
681 	writel(SLV_RX_ACSA1, idev->base + SLV_RX_CTL);
682 	writel(dec_ctl, idev->base + SLV_ADDR_DEC_CTL);
683 	writel(slave->addr, idev->base + SLV_ADDR_1);
688 	writel(slv_int_mask, idev->base + SLV_INT_ENABLE);
695 	struct axxia_i2c_dev *idev = i2c_get_adapdata(slave->adapter);
698 	writel(GLOBAL_MST_EN, idev->base + GLOBAL_CONTROL);
699 	writel(INT_MST, idev->base + INTERRUPT_ENABLE);
701 	synchronize_irq(idev->irq);
703 	idev->slave = NULL;
723 	struct axxia_i2c_dev *idev = NULL;
727 	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
728 	if (!idev)
735 	idev->irq = platform_get_irq(pdev, 0);
736 	if (idev->irq < 0)
737 		return idev->irq;
739 	idev->i2c_clk = devm_clk_get(&pdev->dev, "i2c");
740 	if (IS_ERR(idev->i2c_clk)) {
742 		return PTR_ERR(idev->i2c_clk);
745 	idev->base = base;
746 	idev->dev = &pdev->dev;
747 	init_completion(&idev->msg_complete);
749 	of_property_read_u32(np, "clock-frequency", &idev->bus_clk_rate);
750 	if (idev->bus_clk_rate == 0)
751 		idev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ;	/* default clock rate */
753 	ret = clk_prepare_enable(idev->i2c_clk);
759 	ret = axxia_i2c_init(idev);
765 	ret = devm_request_irq(&pdev->dev, idev->irq, axxia_i2c_isr, 0,
766 			       pdev->name, idev);
768 		dev_err(&pdev->dev, "failed to claim IRQ%d\n", idev->irq);
772 	i2c_set_adapdata(&idev->adapter, idev);
773 	strscpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
774 	idev->adapter.owner = THIS_MODULE;
775 	idev->adapter.algo = &axxia_i2c_algo;
776 	idev->adapter.bus_recovery_info = &axxia_i2c_recovery_info;
777 	idev->adapter.quirks = &axxia_i2c_quirks;
778 	idev->adapter.dev.parent = &pdev->dev;
779 	idev->adapter.dev.of_node = pdev->dev.of_node;
781 	platform_set_drvdata(pdev, idev);
783 	ret = i2c_add_adapter(&idev->adapter);
790 	clk_disable_unprepare(idev->i2c_clk);
796 	struct axxia_i2c_dev *idev = platform_get_drvdata(pdev);
798 	clk_disable_unprepare(idev->i2c_clk);
799 	i2c_del_adapter(&idev->adapter);