i2c/busses/i2c-microchip-corei2c.c

129 static void mchp_corei2c_core_disable(struct mchp_corei2c_dev *idev)
131 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
134 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
137 static void mchp_corei2c_core_enable(struct mchp_corei2c_dev *idev)
139 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
142 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
145 static void mchp_corei2c_reset(struct mchp_corei2c_dev *idev)
147 	mchp_corei2c_core_disable(idev);
148 	mchp_corei2c_core_enable(idev);
151 static inline void mchp_corei2c_stop(struct mchp_corei2c_dev *idev)
153 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
156 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
160 					   struct mchp_corei2c_dev *idev)
183 	ctrl = readb(idev->base + CORE_I2C_CTRL);
186 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
188 	ctrl = readb(idev->base + CORE_I2C_CTRL);
195 static int mchp_corei2c_init(struct mchp_corei2c_dev *idev)
197 	u32 clk_rate = clk_get_rate(idev->i2c_clk);
198 	u32 divisor = clk_rate / idev->bus_clk_rate;
201 	ret = mchp_corei2c_set_divisor(divisor, idev);
205 	mchp_corei2c_reset(idev);
210 static void mchp_corei2c_empty_rx(struct mchp_corei2c_dev *idev)
214 	if (idev->msg_len > 0) {
215 		*idev->buf++ = readb(idev->base + CORE_I2C_DATA);
216 		idev->msg_len--;
219 	if (idev->msg_len <= 1) {
220 		ctrl = readb(idev->base + CORE_I2C_CTRL);
222 		writeb(ctrl, idev->base + CORE_I2C_CTRL);
226 static int mchp_corei2c_fill_tx(struct mchp_corei2c_dev *idev)
228 	if (idev->msg_len > 0)
229 		writeb(*idev->buf++, idev->base + CORE_I2C_DATA);
230 	idev->msg_len--;
235 static void mchp_corei2c_next_msg(struct mchp_corei2c_dev *idev)
240 	if (idev->current_num >= idev->total_num) {
241 		complete(&idev->msg_complete);
250 	if (idev->msg_err) {
251 		complete(&idev->msg_complete);
255 	this_msg = idev->msg_queue++;
257 	if (idev->current_num < (idev->total_num - 1)) {
258 		struct i2c_msg *next_msg = idev->msg_queue;
260 		idev->restart_needed = next_msg->flags & I2C_M_RD;
262 		idev->restart_needed = false;
265 	idev->addr = i2c_8bit_addr_from_msg(this_msg);
266 	idev->msg_len = this_msg->len;
267 	idev->buf = this_msg->buf;
269 	ctrl = readb(idev->base + CORE_I2C_CTRL);
271 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
273 	idev->current_num++;
276 static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev)
278 	u32 status = idev->isr_status;
282 	if (!idev->buf)
288 		ctrl = readb(idev->base + CORE_I2C_CTRL);
290 		writeb(idev->addr, idev->base + CORE_I2C_DATA);
291 		writeb(ctrl, idev->base + CORE_I2C_CTRL);
294 		idev->msg_err = -EAGAIN;
299 		if (idev->msg_len > 0) {
300 			mchp_corei2c_fill_tx(idev);
302 			if (idev->restart_needed)
311 		idev->msg_err = -ENXIO;
315 		ctrl = readb(idev->base + CORE_I2C_CTRL);
316 		if (idev->msg_len == 1u) {
318 			writeb(ctrl, idev->base + CORE_I2C_CTRL);
321 			writeb(ctrl, idev->base + CORE_I2C_CTRL);
323 		if (idev->msg_len < 1u)
327 		mchp_corei2c_empty_rx(idev);
330 		mchp_corei2c_empty_rx(idev);
331 		if (idev->msg_len == 0)
340 		mchp_corei2c_stop(idev);
343 		mchp_corei2c_next_msg(idev);
350 	struct mchp_corei2c_dev *idev = _dev;
354 	ctrl = readb(idev->base + CORE_I2C_CTRL);
356 		idev->isr_status = readb(idev->base + CORE_I2C_STATUS);
357 		ret = mchp_corei2c_handle_isr(idev);
360 	ctrl = readb(idev->base + CORE_I2C_CTRL);
362 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
370 	struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap);
375 	mchp_corei2c_core_enable(idev);
381 	idev->restart_needed = false;
382 	idev->msg_queue = msgs;
383 	idev->total_num = num;
384 	idev->current_num = 0;
390 	idev->addr = i2c_8bit_addr_from_msg(this_msg);
391 	idev->msg_len = this_msg->len;
392 	idev->buf = this_msg->buf;
393 	idev->msg_err = 0;
395 	if (idev->total_num > 1) {
398 		idev->restart_needed = next_msg->flags & I2C_M_RD;
401 	idev->current_num++;
402 	idev->msg_queue++;
404 	reinit_completion(&idev->msg_complete);
409 	ctrl = readb(idev->base + CORE_I2C_CTRL);
411 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
413 	time_left = wait_for_completion_timeout(&idev->msg_complete,
414 						idev->adapter.timeout);
418 	if (idev->msg_err)
419 		return idev->msg_err;
434 	struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap);
509 	ret = mchp_corei2c_xfer(&idev->adapter, msgs, num_msgs);
540 	struct mchp_corei2c_dev *idev;
544 	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
545 	if (!idev)
548 	idev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
549 	if (IS_ERR(idev->base))
550 		return PTR_ERR(idev->base);
556 	idev->i2c_clk = devm_clk_get(&pdev->dev, NULL);
557 	if (IS_ERR(idev->i2c_clk))
558 		return dev_err_probe(&pdev->dev, PTR_ERR(idev->i2c_clk),
561 	idev->dev = &pdev->dev;
562 	init_completion(&idev->msg_complete);
564 	ret = device_property_read_u32(idev->dev, "clock-frequency",
565 				       &idev->bus_clk_rate);
566 	if (ret || !idev->bus_clk_rate) {
568 		idev->bus_clk_rate = 100000;
571 	if (idev->bus_clk_rate > 400000)
574 				     idev->bus_clk_rate);
582 			       pdev->name, idev);
587 	ret = clk_prepare_enable(idev->i2c_clk);
592 	ret = mchp_corei2c_init(idev);
594 		clk_disable_unprepare(idev->i2c_clk);
598 	i2c_set_adapdata(&idev->adapter, idev);
599 	snprintf(idev->adapter.name, sizeof(idev->adapter.name),
601 	idev->adapter.owner = THIS_MODULE;
602 	idev->adapter.algo = &mchp_corei2c_algo;
603 	idev->adapter.dev.parent = &pdev->dev;
604 	idev->adapter.dev.of_node = pdev->dev.of_node;
605 	idev->adapter.timeout = HZ;
607 	platform_set_drvdata(pdev, idev);
609 	ret = i2c_add_adapter(&idev->adapter);
611 		clk_disable_unprepare(idev->i2c_clk);
622 	struct mchp_corei2c_dev *idev = platform_get_drvdata(pdev);
624 	clk_disable_unprepare(idev->i2c_clk);
625 	i2c_del_adapter(&idev->adapter);